Journal of Cachexia Sarcopenia and Muscle

Astaxanthin stimulates mitochondrial biogenesis in insulin resistant muscle via activation of AMPK pathway

31-01-2020 – Yasuhiro Nishida, Allah Nawaz, Tomonobu Kado, Akiko Takikawa, Yoshiko Igarashi, Yasuhiro Onogi, Tsutomu Wada, Toshiyasu Sasaoka, Seiji Yamamoto, Masakiyo Sasahara, Johji Imura, Kumpei Tokuyama, Isao Usui, Takashi Nakagawa, Shiho Fujisaka, Yagi Kunimasa, Kazuyuki Tobe

Abstract
Background
Skeletal muscle is mainly responsible for insulin‐stimulated glucose disposal. Dysfunction in skeletal muscle metabolism especially during obesity contributes to the insulin resistance. Astaxanthin (AX), a natural antioxidant, has been shown to ameliorate hepatic insulin resistance in obese mice. However, its effects in skeletal muscle are poorly understood. The current study aimed to investigate the molecular target of AX in ameliorating skeletal muscle insulin resistance.
Methods
We fed 6‐week‐old male C57BL/6J mice with normal chow (NC) or NC supplemented with AX (NC+AX) and high‐fat‐diet (HFD) or HFD supplemented with AX for 24 weeks. We determined the effect of AX on various parameters including insulin sensitivity, glucose uptake, inflammation, kinase signaling, gene expression, and mitochondrial function in muscle. We also determined energy metabolism in intact C2C12 cells treated with AX using the Seahorse XFe96 Extracellular Flux Analyzer and assessed the effect of AX on mitochondrial oxidative phosphorylation and mitochondrial biogenesis.
Results
AX‐treated HFD mice showed improved metabolic status with significant reduction in blood glucose, serum total triglycerides, and cholesterol (p< 0.05). AX‐treated HFD mice also showed improved glucose metabolism by enhancing glucose incorporation into peripheral target tissues, such as the skeletal muscle, rather than by suppressing gluconeogenesis in the liver as shown by hyperinsulinemic–euglycemic clamp study. AX activated AMPK in the skeletal muscle of the HFD mice and upregulated the expressions of transcriptional factors and coactivator, thereby inducing mitochondrial remodeling, including increased mitochondrial oxidative phosphorylation component and free fatty acid metabolism. We also assessed the effects of AX on mitochondrial biogenesis in the si
RNA‐mediated AMPK‐depleted C2C12 cells and showed that the effect of AX was lost in the genetically AMPK‐depleted C2C12 cells. Collectively, AX treatment (i) significantly ameliorated insulin resistance and glucose intolerance through regulation of AMPK activation in the muscle, (ii) stimulated mitochondrial biogenesis in the muscle, (iii) enhanced exercise tolerance and exercise‐induced fatty acid metabolism, and (iv) exerted antiinflammatory effects via its antioxidant activity in adipose tissue.
Conclusions
We concluded that AX treatment stimulated mitochondrial biogenesis and significantly ameliorated insulin resistance through activation of AMPK pathway in the skeletal muscle.

A counterintuitive perspective for the role of fat‐free mass in metabolic health

30-01-2020 – Jean‐Christophe Lagacé, Martin Brochu, Isabelle J. Dionne

Editorial

Abstract
Fat‐free mass (FFM) has long been recognized to play a role in metabolic homeostasis. Over the years, it has become widely accepted by the scientific and general community alike that having a greater FFM can be protective for metabolic health. Hence, in the context of an aging population concurrently facing sarcopenia and an elevated incidence of metabolic diseases, substantial efforts are being made to study and develop interventions aiming to maintain or increase FFM. However, accumulating evidence now suggests that a large FFM may be deleterious to metabolic health, at least in some populations. The objective of this article is thus to raise awareness surrounding these results and to explore possible explanations and mechanisms underlying this counterintuitive association.

Muscle loss during primary debulking surgery and chemotherapy predicts poor survival in advanced‐stage ovarian cancer

30-01-2020 – Chueh‐Yi Huang, Yuh‐Cheng Yang, Tze‐Chien Chen, Jen‐Ruei Chen, Yu‐Jen Chen, Meng‐Hao Wu, Ya‐Ting Jan, Chih‐Long Chang, Jie Lee

Journal Article

Abstract
Background
Sarcopenia is commonly observed in patients with advanced‐stage epithelial ovarian cancer (EOC). However, the effect of body composition changes—during primary debulking surgery (PDS) and adjuvant platinum‐based chemotherapy—on outcomes of patients with advanced‐stage EOC is unknown. This study aimed to evaluate the association between body composition changes and outcomes of patients with stage III EOC treated with PDS and adjuvant platinum‐based chemotherapy.
Methods
Pre‐treatment and post‐treatment computed tomography (CT) images of 139 patients with stage III EOC were analysed. All CT images were contrast‐enhanced scans and were acquired according to a standardized protocol. The skeletal muscle index (SMI), skeletal muscle radiodensity (SMD), and total adipose tissue index were measured using CT images obtained at the L3 vertebral level. Predictors of overall survival were identified using Cox regression models.
Results
The median follow‐up was 37.9 months. The median duration between pre‐treatment and post‐treatment CT was 182 days (interquartile range: 161–225 days). Patients experienced an average SMI loss of 1.8%/180 days (95% confidence interval: −3.1 to −0.4; P = 0.01) and SMD loss of 1.7%/180 days (95% confidence interval: −3.3 to −0.03; P = 0.046). SMI and SMD changes were weakly correlated with body mass index changes (Spearman ρ for SMI, 0.15, P = 0.07; ρ for SMD, 0.02, P = 0.82). The modified Glasgow prognostic score was associated with SMI loss (odds ratio: 2.42, 95% confidence interval: 1.03–5.69; P = 0.04). The median time to disease recurrence was significantly shorter in patients with SMI loss ≥5% after treatment than in those with SMI loss <5% or gain (5.4 vs. 11.2 months, P = 0.01). Pre‐treatment SMI (1 cm2/m2 decrease; hazard ratio: 1.08, 95% confidence interval: 1.03–1.11; P = 0.002) and SMI change (1%/180 days decrease; hazard ratio: 1.04, 95% confidence interval: 1.01–1.08; P = 0.002) were independently associated with poorer overall survival. SMD, body mass index, and total adipose tissue index at baseline and changes were not associated with overall survival.
Conclusions
Skeletal muscle index decreased significantly during treatment and was independently associated with poor overall survival in patients with stage III EOC treated with PDS and adjuvant platinum‐based chemotherapy. The modified Glasgow prognostic score might be a predictor of SMI loss during treatment.

Comprehensive geriatric intervention in community‐dwelling older adults: a cluster‐randomized controlled trial

29-01-2020 – Yuya Watanabe, Yosuke Yamada, Tsukasa Yoshida, Keiichi Yokoyama, Motoko Miyake, Emi Yamagata, Minoru Yamada, Yasuko Yoshinaka, Misaka Kimura, for Kyoto‐Kameoka Study Group

Journal Article

Abstract
Background
In longevity societies, one of the most serious social issues is sarcopenia and/or frailty. Preventing them is important for maintaining independence and quality of life in the older population. This study investigated the effect of a self‐monitoring comprehensive geriatric intervention programme (CGIP) on physical function and muscle size in community‐dwelling older adults. We compared the effects of a CGIP using weekly class‐styled (CS) sessions and a home‐based (HB) programme.
Methods
The 526 participants were randomized into one of two groups (CS 251, HB 275) based on their residential districts. We conducted a 12 week CGIP, which consisted of low‐load resistance exercise, physical activity increments, oral function improvements, and a nutritional guide. All participants were encouraged to attend two 90 min lectures that included instructions on the CGIP. They were provided with exercise materials (triaxial‐accelerometers/pedometers, ankle weights, and elastic bands) and diary logs. The CS group attended 90 min weekly sessions and independently executed the programme on other days, whereas the HB group only received instructions on how to execute the programme. Physical functions, such as knee extension strength (KES), normal and maximum walking speed, the timed up‐and‐go test, and anterior thigh muscle thickness (MT), were measured and analysed using intention‐to‐treat analysis before and after the 12 week intervention.
Results
Of the 526 participants identified, 517 (CS 243 age 74.0 ± 5.4 women 57.2%, HB 274 age 74.0 ± 5.6 women 58.8%) were enrolled. Nine (CS 8, HB 1) were excluded from the analysis because they did not participate in the pre‐intervention measurements. Both interventions significantly improved KES (CS 18.5%, HB 10.6%), normal walking speed (CS 3.7%, HB 2.8%), and MT (CS 3.2%, HB 3.5%). Greater improvement of KES was observed in the CS group (P = 0.003). Maximum walking speed (CS 4.7%, HB 1.8%; P = 0.001) and timed up‐and‐go (CS −4.7%, HB −0.2%; P < 0.001) significantly improved in the CS group only.
Conclusions
The intervention was effective in preventing sarcopenia and/or frailty. Most physical functions and MT improved after both interventions. The HB intervention is cost‐effective and may help prevent sarcopenia and/or frailty in the large older population.

Vibration and β‐hydroxy‐β‐methylbutyrate treatment suppresses intramuscular fat infiltration and adipogenic differentiation in sarcopenic mice

28-01-2020 – Jinyu Wang, Can Cui, Yu Ning Chim, Hao Yao, Liu Shi, Jiankun Xu, Jiali Wang, Ronald Man Yeung Wong, Kwok‐Sui Leung, Simon Kwoon‐Ho Chow, Wing Hoi Cheung

Journal Article

Abstract
Background
Sarcopenia is an aging‐induced deterioration of skeletal muscle mass and function. Low‐magnitude high‐frequency vibration (LMHFV) was shown to improve muscle functions and β‐hydroxy‐β‐methylbutyrate (HMB) to increase muscle mass and strength. Muscle‐derived stem cells (MDSCs) are progenitor cells important for muscle regeneration. We hypothesized that LMHFV and HMB could retard sarcopenia by reducing fat infiltration through inhibiting adipogenesis in MDSCs.
Methods
Senescence‐accelerated mouse P8 male mice were randomized into control (CTL), HMB, LMHFV (VIB), and combined (COM) groups. Interventions started at age of month 7 and assessed at 1, 2, and 3 months post‐intervention by densitometry, histology, and functional tests. In vitro, MDSCs isolated from gastrocnemius of senescence‐accelerated mouse P8 mice were characterized, randomized into CTL, VIB, HMB, and COM groups, and assessed by oil red O staining, m
RNA, and protein expression.
Results
At 2 months post‐intervention, percentage lean mass of HMB, VIB, and COM groups were significantly higher than CTL group. Twitch, tetanic, and specific tetanic forces of COM group were higher, while specific twitch force of both VIB and COM groups were higher. Grip strength of HMB, VIB, and COM groups were higher. Histologically, both VIB and COM groups presented lower oil red O area than CTL group. Type I muscle fibre in CTL group was higher than HMB, VIB, and COM groups. MDSC were detected in situ by immunofluorescence stain with stem cell antigen‐1 signals confirmed with higher β‐catenin expression in the COM group. The observations were also confirmed in vitro, MDSCs in the HMB, VIB, and COM groups presented lower adipogenesis vs. the CTL group. β‐Catenin m
RNA and protein expressions were lower in the CTL group while their relationship was further validated through β‐catenin knock‐down approach.
Conclusions
Our results showed that combined LMHFV and HMB interventions enhanced muscle strength and decreased percentage fat mass and intramuscular fat infiltration as compared with either treatment alone. Additive effect of LMHFV and HMB was demonstrated in β‐catenin expression than either treatment in MDSCs and altered cell fate from adipogenesis to myogenesis, leading to inhibition of intramuscular lipid accumulation. Wnt/β‐catenin signalling pathway was found to be the predominant regulatory mechanism through which LMHFV and HMB combined treatment suppressed MDSCs adipogenesis.

Comparative proteomic analyses of Duchenne muscular dystrophy and Becker muscular dystrophy muscles: changes contributing to preserve muscle function in Becker muscular dystrophy patients

28-01-2020 – Daniele Capitanio, Manuela Moriggi, Enrica Torretta, Pietro Barbacini, Sara De Palma, Agnese Viganò, Hanns Lochmüller, Francesco Muntoni, Alessandra Ferlini, Marina Mora, Cecilia Gelfi

Journal Article

Abstract
Background
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are characterized by muscle wasting leading to loss of ambulation in the first or third decade, respectively. In DMD, the lack of dystrophin hampers connections between intracellular cytoskeleton and cell membrane leading to repeated cycles of necrosis and regeneration associated with inflammation and loss of muscle ordered structure. BMD has a similar muscle phenotype but milder. Here, we address the question whether proteins at variance in BMD compared with DMD contribute to the milder phenotype in BMD, thus identifying a specific signature to be targeted for DMD treatment.
Methods
Proteins extracted from skeletal muscle from DMD/BMD patients and young healthy subjects were either reduced and solubilized prior two‐dimensional difference in gel electrophoresis/mass spectrometry differential analysis or tryptic digested prior label‐free liquid chromatography with tandem mass spectrometry. Statistical analyses of proteins and peptides were performed by De
Cyder and Perseus software and protein validation and verification by immunoblotting.
Results
Proteomic results indicate minor changes in the extracellular matrix (ECM) protein composition in BMD muscles with retention of mechanotransduction signalling, reduced changes in cytoskeletal and contractile proteins. Conversely, in DMD patients, increased levels of several ECM cytoskeletal and contractile proteins were observed whereas some proteins of fast fibres and of Z‐disc decreased. Detyrosinated alpha‐tubulin was unchanged in BMD and increased in DMD although neuronal nitric oxide synthase was unchanged in BMD and greatly reduced in DMD. Metabolically, the tissue is characterized by a decrement of anaerobic metabolism both in DMD and BMD compared with controls, with increased levels of the glycogen metabolic pathway in BMD. Oxidative metabolism is severely compromised in DMD with impairment of malate shuttle; conversely, it is active in BMD supporting the tricarboxylic acid cycle and respiratory chain. Adipogenesis characterizes DMD, whereas proteins involved in fatty acids beta‐oxidation are increased in BMD. Proteins involved in protein/amino acid metabolism, cell development, calcium handling, endoplasmic reticulum/sarcoplasmic reticulum stress response, and inflammation/immune response were increased in DMD. Both disorders are characterized by the impairment of N‐linked protein glycosylation in the endoplasmic reticulum. Authophagy was decreased in DMD whereas it was retained in BMD.
Conclusions
The mechanosensing and metabolic disruption are central nodes of DMD/BMD phenotypes. The ECM proteome composition and the metabolic rewiring in BMD lead to preservation of energy levels supporting autophagy and cell renewal, thus promoting the retention of muscle function. Conversely, DMD patients are characterized by extracellular and cytoskeletal protein dysregulation and by metabolic restriction at the level of α‐ketoglutarate leading to shortage of glutamate‐derived molecules that over time triggers lipogenesis and lipotoxicity.

The mechanisms and treatments for sarcopenia: could exosomes be a perspective research strategy in the future?

27-01-2020 – Shuang Rong, Liangliang Wang, Zhao Peng, Yuxiao Liao, Dan Li, Xuefeng Yang, Andreas K. Nuessler, Liegang Liu, Wei Bao, Wei Yang

Journal Article, Review

Abstract
The age‐related loss of muscle mass and muscle function known as sarcopenia is a primary contributor to the problems faced by the old people. Sarcopenia has been a major public health problem with high prevalence in many countries. The related underlying molecular mechanisms of sarcopenia are not completely understood. This review is focused on the potential mechanisms and current research strategies for sarcopenia with the aim of facilitating the recognition and treatment of age‐related sarcopenia. Previous studies suggested that protein synthesis and degradation, autophagy, impaired satellite cell activation, mitochondria dysfunction, and other factors associated with muscle weakness and muscle degeneration may be potential molecular pathophysiology of sarcopenia. Importantly, we also prospectively highlight that exosomes (small vesicles) as carriers can regulate muscle regeneration and protein synthesis according to recent researches. Dietary strategies and exercise represent the interventions that can also alleviate the progression of sarcopenia. At last, building on recent studies pointing to exosomes with the roles in increasing muscle regeneration, mediating the beneficial effects of exercise, and serving as messengers of intercellular communication and as carriers for research strategies of many diseases, we propose that exosomes could be a potential research direction or strategies of sarcopenia in the future.

Lipid is heterogeneously distributed in muscle and associates with low radiodensity in cancer patients

27-01-2020 – Amritpal S. Bhullar, Ana Anoveros‐Barrera, Abha Dunichand‐Hoedl, Karen Martins, David Bigam, Rachel G. Khadaroo, Todd McMullen, Oliver F. Bathe, Charles T. Putman, Michael T. Clandinin, Vickie E. Baracos, Vera C. Mazurak

Journal Article

Abstract
Background
Low muscle radiodensity is associated with mortality in a variety of cancer types. Biochemical and morphological correlates are unknown. We aimed to evaluate triglyceride (TG) content and location as a function of computed tomography (CT)‐derived measures of skeletal muscle radiodensity in cancer patients.
Methods
Rectus abdominis (RA) biopsies were collected during cancer surgery from 75 patients diagnosed with cancer. Thin‐layer chromatography and gas chromatography were used for quantification of TG content of the muscle. Axial CT images of lumbar vertebra were used to measure muscle radiodensity. Oil Red O staining was used to determine the location of neutral lipids in frozen muscle sections.
Results
There was wide variation in RA radiodensity in repeated measures (CV% ranged from 3 to 55% based on 10 serial images) as well as within one slice (CV% ranged from 6 to 61% based on 10 subregions). RA radiodensity and total lumbar muscle radiodensity were inversely associated with TG content of RA (r = −0.396, P < 0.001, and r = −0.355, P = 0.002, respectively). Of the total percentage area of muscle staining positive for neutral lipid, 54 ± 17% was present as extramyocellular lipids (range 23.5–77.8%) and 46 ± 17% (range 22.2–76.5%) present as intramyocellular lipid droplets.
Conclusions
Repeated measures revealed wide variation in radiodensity of RA muscle, both vertically and horizontally. Low muscle radiodensity reflects high level of TG in patients with cancer. Non‐uniform distribution of intramyocellular and extramyocellular lipids was evident using light microscopy. These results warrant investigation of mechanisms resulting in lipid deposition in muscles of cancer patients.

AdipoRon, a new therapeutic prospect for Duchenne muscular dystrophy

21-01-2020 – Michel Abou‐Samra, Camille M. Selvais, Raphael Boursereau, Sophie Lecompte, Laurence Noel, Sonia M. Brichard

Journal Article

Abstract
Background
Adiponectin (Ap
N) is a hormone known to exhibit insulin‐sensitizing, fat‐burning, and anti‐inflammatory properties in several tissues, including the skeletal muscle. Duchenne muscular dystrophy (DMD) is a devastating disease characterized by dystrophin deficiency with subsequent chronic inflammation, myofiber necrosis, and impaired regeneration. Previously, we showed that transgenic up‐regulation of Ap
N could significantly attenuate the dystrophic phenotype in mdx mice (model of DMD). Recently, an orally active Ap
N receptor agonist, Adipo
Ron, has been identified. This synthetic small molecule has the advantage of being more easily produced and administrable than Ap
N. The aim of this study was to investigate the potential effects of Adipo
Ron on the dystrophic muscle.
Methods
Four‐week‐old mdx mice (n = 6–9 per group) were orally treated with Adipo
Ron (mdx‐AR) for 8 weeks and compared with untreated (mdx) mice and to control (wild‐type) mice. In vivo functional tests were carried out to measure the global force and endurance of mice. Ex vivo biochemical and molecular analyses were performed to evaluate the pathophysiology of the skeletal muscle. Finally, in vitro tests were conducted on primary cultures of healthy and DMD human myotubes.
Results
Adipo
Ron treatment mitigated oxidative stress (−30% to 45% for 4‐hydroxy‐2‐nonenal and peroxiredoxin 3, P < 0.0001) as well as inflammation in muscles of mdx mice (−35% to 65% for interleukin 1 beta, tumour necrosis factor alpha, and cluster of differentiation 68, a macrophage maker, P < 0.0001) while increasing the anti‐inflammatory cytokine, interleukin 10 (~5‐fold, P < 0.0001). Adipo
Ron also improved the myogenic programme as assessed by a ~2‐fold rise in markers of muscle proliferation and differentiation (P < 0.01 or less vs. untreated mdx). Plasma lactate dehydrogenase and creatine kinase were reduced by 30–40% in mdx‐AR mice, reflecting less sarcolemmal damage (P < 0.0001). When compared with untreated mdx mice, mdx‐AR mice exhibited enhanced physical performance with an increase in both muscle force and endurance and a striking restoration of the running capacity during eccentric exercise. Adipo
Ron mainly acted through Ap
N receptor 1 by increasing AMP‐activated protein kinase signalling, which led to repression of nuclear factor‐kappa B, up‐regulation of utrophin (a dystrophin analogue), and a switch towards an oxidative and more resistant fibre phenotype. The effects of Adipo
Ron were then recapitulated in human DMD myotubes.
Conclusions
These results demonstrate that Adipo
Ron exerts several beneficial effects on the dystrophic muscle. This molecule could offer promising therapeutic prospect for managing DMD or other muscle and inflammatory disorders.

Reference values for skeletal muscle mass and fat mass measured by bioelectrical impedance in 390xa0565 UK adults

13-01-2020 – Mei‐Man Lee, Susan A. Jebb, Jason Oke, Carmen Piernas

Journal Article

Abstract
Background
Loss of skeletal muscle mass (SMM) increases the risk of frailty and, together with excess fat mass (FM), is a risk factor for cardio‐metabolic disease. However, use of body composition measurements in nutritional surveillance and routine clinical practice is limited by the lack of reference data. Our aim was to produce age‐specific and sex‐specific reference values for SMM and FM in the White ethnic adult population in the UK. Secondary objectives were to examine the tracking over time using a subsample of the population with repeated measures of body composition and to assess the validity of these reference values in different ethnic subgroups.
Methods
We used data from segmental bioelectrical impedance analysis (BIA) in 390 565 participants, aged 40–69 years, in the UK Biobank, and data from dual‐energy X‐ray absorptiometry from n = 905 participants to validate the BIA measurements. SMM was calculated as the sum of the predicted muscle mass from the limbs. The LMS method was used to produce percentile curves for the SMM index (SMMI = SMM/height2) and the FM index (FMI = FM/height2). We investigated the validity of the White ethnic reference values by plotting z‐scores (99.7% confidence interval) from Black and Asian groups to check if their confidence interval included zero. Longitudinal trajectories were predicted based on the baseline z‐scores and the correlation between repeated measurements at follow‐up.
Results
The percentile curves show that SMMI declines in men from the age of 40, whereas in women, SMMI is more stable and decreases only slightly among women in the higher percentiles. FMI increases with age in both men and women. Women have higher FMI and lower SMMI than men in all age groups. The validity of the White‐based reference values for non‐White ethnic groups is poor. Longitudinal trajectories in body composition in the subsample of participants with a follow‐up assessment show regression towards the mean in both men and women, with some evidence of declining SMMI only among men. The predicted 90% limits for the expected 5 year trajectories of SMMI and FMI can be used to identify people with unusual trajectories and in clinical practice to identify and track individuals at risk of excessive loss of SMM.
Conclusions
These body composition reference values developed from BIA in a middle/older‐aged healthy White ethnic population in the UK could be used as a simple assessment tool for nutritional surveillance and to identify individuals with low SMMI or high FMI who may be at increased risk of disease and/or frailty.

Paediatric reference values for total psoas muscle area

09-01-2020 – Eberhard Lurz, Hiten Patel, Gerald Lebovic, Claudia Quammie, Jessica P. Woolfson, Manuela Perez, Amanda Ricciuto, Paul W. Wales, Binita M. Kamath, Govind B. Chavhan, Peter Jüni, Vicky L. Ng

Journal Article

Abstract
Background
Sarcopenia, the unintentional loss of skeletal muscle mass, is associated with poor outcomes in adult patient populations. In adults, sarcopenia is often ascertained by cross‐sectional imaging of the psoas muscle area (PMA). Although children with chronic medical illnesses may be at increased risk for muscle loss because of nutritional deficiencies, physical deconditioning, endocrine anomalies, and systemic inflammation, consistent quantitative definitions for sarcopenia in children are lacking. We aimed to generate paediatric reference values for PMA at two intervertebral lumbar levels, L3–4 and L4–5.
Methods
In this cross‐sectional study, we analysed abdominal computed tomography scans of consecutive children presenting to the emergency department. Participants were children 1–16 years who required abdominal cross‐sectional imaging after paediatric trauma between January 1, 2005 and December 31, 2015 in a large Canadian quaternary care centre. Children with a documented chronic medical illness or an acute spinal trauma at presentation were excluded. Total PMA (t
PMA) at levels L3–4 and L4–5 were measured in square millimetres (mm2) as the sum of left and right PMA. Age‐specific and sex‐specific t
PMA percentile curves were modelled using quantile regression.
Results
Computed tomography images from 779 children were included. Values of t
PMA at L4–5 were significantly larger than at L3–4 at all ages, but their correlation was high for both girls (r = 0.95) and boys (r = 0.98). Amongst girls, t
PMA 50th percentile values ranged from 365 to 2336 mm2 at L3–4 and from 447 to 2704 mm2 for L4–5. Amongst boys, 50th percentile values for t
PMA ranged between 394 and 3050 mm2 at L3–4 and from 498 to 3513 mm2 at L4–5. Intraclass correlation coefficients were excellent at L3–4 (0.97, 95% CI 0.94 to 0.981) and L4–5 (0.99, 95% CI 0.986 to 0.995). Weight and t
PMA were correlated, stratified by sex for boys (L3–4 r = 0.90; L4–5 r = 0.90) and for girls (L3–4 r = 0.87; L4–5 r = 0.87). An online application was subsequently developed to easily calculate age‐specific and sex‐specific z‐scores and percentiles.
Conclusions
We provide novel paediatric age‐specific and sex‐specific growth curves for t
PMA at intervertebral L3–4 and L4–5 levels for children between the ages of 1‐16 years. Together with an online tool (https://ahrc‐apps.shinyapps.io/sarcopenia/), these t
PMA curves should serve as a reference enabling earlier identification and targeted intervention of sarcopenia in children with chronic medical conditions.

Which one came first: movement behavior or frailty? A cross‐lagged panel model in the Toledo Study for Healthy Aging

08-01-2020 – Asier Mañas, Borja Pozo‐Cruz, Irene Rodríguez‐Gómez, José Losa‐Reyna, Leocadio Rodríguez‐Mañas, Francisco J. García‐García, Ignacio Ara

Journal Article

Abstract
Background
There has been limited longitudinal assessment of the relationship between moderate‐to‐vigorous physical activity (MVPA) and sedentary behaviour (SB) with frailty, and no studies have explored the possibility of reverse causality. This study aimed to determine the potential bidirectionality of the relationship between accelerometer‐assessed MVPA, SB, and frailty over time in older adults.
Methods
Participants were from the Toledo Study for Healthy Aging. We analysed 186 older people aged 67 to 90 (76.7 ± 3.9; 52.7% female participants) over a 4‐year period. Time spent in SB and MVPA was assessed by accelerometry. Frailty Trait Scale was used to determine frailty levels. A cross‐lagged panel model design was used to test the reciprocal relationships between MVPA/SB and frailty.
Results
Frailty Trait Scale score changed from 35.4 to 43.8 points between the two times (P < 0.05). We also found a reduction of 7 min/day in the time spent on MVPA (P < 0.05), and participants tended to spend more time on SB (P = 0.076). Our analyses revealed that lower levels of initial MVPA predicted higher levels of later frailty std. β = −0.126; confidence interval (CI) = −0.231, −0.021; P < 0.05, whereas initial spent time on SB did not predict later frailty (std. β = −0.049; CI = −0.185, 0.087; P = 0.48). Conversely, an initial increased frailty status predicted higher levels of later SB (std. β = 0.167; CI = 0.026, 0.307; P < 0.05) but not those of MVPA (std. β = 0.071; CI = −0.033, 0.175; P = 0.18).
Conclusions
Our observations suggest that the relationship between MVPA/SB and frailty is unidirectional: individuals who spent less time on MVPA at baseline are more likely to increase their frailty score, and individuals who are more frail are more likely to spent more time on SB at follow‐up. Interventions and policies should aim to increase MVPA levels from earlier stages to promote successful aging.

Biomarkers of sarcopenia in very old patients with hip fracture

08-01-2020 – Carmen Sánchez‐Castellano, Sagrario Martín‐Aragón, Paloma Bermejo‐Bescós, Nieves Vaquero‐Pinto, Carmen Miret‐Corchado, Ana Merello de Miguel, Alfonso José Cruz‐Jentoft

Journal Article

Abstract
Background
Hip fracture is both a cause and a consequence of sarcopenia. Older persons with sarcopenia have an increased risk of falling, and the prevalence of sarcopenia may be increased in those who suffer a hip fracture. The aim of this study was to explore potential biomarkers (neuromuscular and peripheral pro‐inflammatory and oxidative stress markers) that may be associated with sarcopenia in very old persons with hip fracture.
Methods
We recruited 150 consecutive patients ≥80 years old admitted to an orthogeriatric unit for an osteoporotic hip fracture. Muscle mass was assessed pre‐operatively using bioelectrical impedance analysis; Janssens (J) and Masanés (M) reference cut‐off points were used to define low muscle mass. Muscle strength was assessed with handgrip strength (Jamars dynamometer). Sarcopenia was defined by having both low muscle mass and strength and using the European Working Group on Sarcopenia in Older People 2 definition of probable sarcopenia (low grip strength). Peripheral markers—pro‐inflammatory and oxidative stress parameters—were determined either in the plasma or in the erythrocyte fraction obtained from peripheral whole blood of every patient pre‐operatively.
Results
Mean age was 87.6 ± 4.9 years, and 78.7% were women. The prevalence of sarcopenia was 11.5% with Janssens, 34.9% with Masanés cut‐offs, and 93.3% with the European Working Group on Sarcopenia in Older People 2 definition of probable sarcopenia. Among the four pro‐inflammatory cytokines tested in plasma, only tumour necrosis factor‐α was different (lower) in sarcopenic than in non‐sarcopenic participants using both muscle mass cut‐offs (J 7.9 ± 6.2 vs. 8.3 ± 5.8, M 6.8 ± 4.7 vs. 9.1 ± 6.2). Erythrocyte glutathione system showed a non‐significant tendency to lower glutathione levels and glutathione/oxidized glutathione ratios in sarcopenic participants compared with non‐sarcopenic subjects. Catalase activity was also lower in sarcopenic participants (J 2904 ± 1429 vs. 3329 ± 1483, M 3037 ± 1430 vs. 3431 ± 1498). No significant differences were found between groups in chymotrypsin‐like activity of the 20S proteasome, superoxide dismutase, glutathione peroxidase and butyrylcholinesterase activity, C‐terminal agrin fragment, interferon‐γ, or interleukin‐1β.
Conclusions
The prevalence of sarcopenia in patients with hip fracture varies according to the definition and the muscle mass reference cut‐off points used. We did not find differences in most neuromuscular, pro‐inflammatory, or oxidative stress markers, except for lower peripheral tumour necrosis factor‐α levels and catalase activity in sarcopenic participants, which may be markers of an early inflammatory reaction that is hampered in sarcopenic patients.

Comparison of multidimensional frailty score, grip strength, and gait speed in older surgical patients

08-01-2020 – Jung‐Yeon Choi, Kwang‐il Kim, YoungRok Choi, Sang‐Hoon Ahn, Eunyoung Kang, Heung‐Kwon Oh, Duck‐Woo Kim, Eun‐Kyu Kim, Yoo‐Seok Yoon, Sung‐Bum Kang, Hyung‐Ho Kim, Ho‐Seong Han, Cheol‐Ho Kim

Journal Article

Abstract
Background
Frail older adults are at increased risk of post‐operative morbidity compared with robust counterparts. Simple methods testing frailty such as grip strength or gait speed have shown promising results for predicting post‐operative outcome, but there is a debate regarding the most appropriate and precise frailty assessment method. We compared the predictive value of multidimensional frailty score (MFS) with grip strength, gait speed, or conventional risk stratification tool for predicting post‐operative complications in older surgical patients.
Methods
From January 2016 to June 2017, 648 older surgical patients (age ≥ 65 years) were included for analysis. MFS was calculated based on the preoperative comprehensive geriatric assessment. Grip strength and gait speed were measured before surgery. The primary outcome was a composite of post‐operative complications (e.g. pneumonia, urinary tract infection, delirium, acute pulmonary thromboembolism, and unplanned intensive care unit admission). The secondary outcome was the 6 month all‐cause mortality.
Results
Among 648 patients (mean age 76.6 ± 5.4 years, 52.8% female), 66 (10.2%) patients experienced post‐operative complications, and the 6 month mortality was 3.9% (n = 25). Grip strength, gait speed, MFS, and American Society of Anesthesiologists (ASA) classification could predict post‐operative complication but only MFS (hazard ratio = 1.581, 95% confidence interval 1.276–1.959, P < 0.001) could predict 6 month mortality after adjustment. MFS (C‐index = 0.750) had a superior prognostic utility compared with age (0.638, P = 0.008), grip strength (0.566, P < 0.001), and ASA classification (0.649, P = 0.004). MFS improved the predictive value on age C‐index of 0.638 (age) vs. 0.758 (age + MFS), P < 0.001 and ASA classification C‐index of 0.649 (ASA) vs. 0.765 (ASA + MFS), P < 0.001 for post‐operative complication; however, gait speed or grip strength did not provide additional prognostic value in both age and ASA.
Conclusions
Multidimensional frailty score based on preoperative comprehensive geriatric assessment showed better utility than age, grip strength, gait speed, or ASA classification for predicting post‐operative complication and 6 month mortality. MFS also showed incremental predictive ability for post‐operative complications with the addition of age and ASA classification. Accordingly, MFS is superior to grip strength or gait speed for predicting complications among older surgical patients.

Nutrition interventions to treat low muscle mass in cancer

08-01-2020 – Carla M. Prado, Sarah A. Purcell, Alessandro Laviano

Journal Article, Review

Abstract
Many patients with cancer experience poor nutritional status, which detrimentally impacts clinical outcomes. Poor nutritional status in cancer is primarily manifested by severe muscle mass (MM) depletion, which may occur at any stage (from curative to palliative) and often co‐exists with obesity. The objective of this article was to discuss gaps and opportunities related to the role of nutrition in preventing and reversing low MM in cancer. It also provides a narrative review of relevant nutritional interventions for patients capable of oral intake. The impact of nutrition interventions to prevent/treat low MM in cancer is not well understood, potentially due to the limited number of studies and of clinically viable, accurate body composition assessment tools. Additionally, the type of study designs, inclusion criteria, length of intervention, and choice of nutritional strategies have not been optimal, likely underestimating the anabolic potential of nutrition interventions. Nutrition studies are also often of short duration, and interventions that adapt to the metabolic and behavioural changes during the clinical journey are needed. We discuss energy requirements (25–30 kcal/kg/day) and interventions of protein (1.0–1.5 g/kg/day), branched‐chain amino acids (leucine: 2–4 g/day), β‐hydroxy β‐methylbutyrate (3 g/day), glutamine (0.3 g/kg/day), carnitine (4–6 g/day), creatine (5 g/day), fish oil/eicosapentanoic acid (2.0–2.2 g/day EPA and 1.5 g/day DHA), vitamin/minerals (e.g. vitamin D: 600–800 international units per day), and multimodal approaches (nutrition, exercise, and pharmaceutical) to countermeasure low MM in cancer. Although the evidence is variable by modality type, interventions were generally not specifically studied in the context of cancer. Understanding patients nutritional requirements could lead to targeted prescriptions to prevent or attenuate low MM in cancer, with the overall aim of minimizing muscle loss during anti‐cancer therapy and maximizing muscle anabolism during recovery. It is anticipated that this will, in turn, improve overall health and prognostication including tolerance to treatment and survival. However, oncology‐specific interventions with more robust study designs are needed to facilitate these goals.

The authors reply: Letter on: “ Sarcopenia and its association with falls and fracturesin older adults: A systematic review andmeta‐analysis” by Zhang et al.

05-01-2020 – Suey S.Y. Yeung, Martijn W. Heymans, Andrea B. Maier

Letter

p300 and cAMP response element‐binding protein‐binding protein in skeletal muscle homeostasis, contractile function, and survival

03-01-2020 – Kristoffer Svensson, Samuel A. LaBarge, Abha Sathe, Vitor F. Martins, Shahriar Tahvilian, Jennifer M. Cunliffe, Roman Sasik, Sushil K. Mahata, Gretchen A. Meyer, Andrew Philp, Larry L. David, Samuel R. Ward, Carrie E. McCurdy, Joseph E. Aslan, Simon Schenk

Journal Article

Abstract
Background
Reversible ε‐amino acetylation of lysine residues regulates transcription as well as metabolic flux; however, roles for specific lysine acetyltransferases in skeletal muscle physiology and function are unknown. In this study, we investigated the role of the related acetyltransferases p300 and cAMP response element‐binding protein‐binding protein (CBP) in skeletal muscle transcriptional homeostasis and physiology in adult mice.
Methods
Mice with skeletal muscle‐specific and inducible knockout of p300 and CBP (PCKO) were generated by crossing mice with a tamoxifen‐inducible Cre recombinase expressed under the human α‐skeletal actin promoter with mice having Lox
P sites flanking exon 9 of the Ep300 and Crebbp genes. Knockout of PCKO was induced at 13–15 weeks of age via oral gavage of tamoxifen for 5 days to both PCKO and littermate control wildtype (WT) mice. Body composition, food intake, and muscle function were assessed on day 0 (D0) through 5 (D5). Microarray and tandem mass tag mass spectrometry analyses were performed to assess global RNA and protein levels in skeletal muscle of PCKO and WT mice.
Results
At D5 after initiating tamoxifen treatment, there was a reduction in body weight (−15%), food intake (−78%), stride length (−46%), and grip strength (−45%) in PCKO compared with WT mice. Additionally, ex vivo contractile function tetanic tension (k
Pa) was severely impaired in PCKO vs. WT mice at D3 (~70–80% lower) and D5 (~80–95% lower) and resulted in lethality within 1 week—a phenotype that is reversed by the presence of a single allele of either p300 or CBP. The impaired muscle function in PCKO mice was paralleled by substantial transcriptional alterations (3310 genes; false discovery rate < 0.1), especially in gene networks central to muscle contraction and structural integrity. This transcriptional uncoupling was accompanied by changes in protein expression patterns indicative of impaired muscle function, albeit to a smaller magnitude (446 proteins; fold‐change > 1.25; false discovery rate < 0.1).
Conclusions
These data reveal that p300 and CBP are required for the control and maintenance of contractile function and transcriptional homeostasis in skeletal muscle and, ultimately, organism survival. By extension, modulating p300/CBP function may hold promise for the treatment of disorders characterized by impaired contractile function in humans.

Comment on: “Sarcopenia and its association with falls and fractures in older adults: A systematic review and meta‐analysis” by Yeung et al.

03-01-2020 – Xiao‐Ming Zhang, Andy S.K. Cheng, Qingli Dou, Wenwu Zhang, Yingchun Zeng

Letter

Sarcopenia, long‐term conditions, and multimorbidity: findings from UK Biobank participants

30-12-2019 – Richard M. Dodds, Antoneta Granic, Sian M. Robinson, Avan A. Sayer

Journal Article

Abstract
Background
Sarcopenia, the loss of muscle strength and mass, predicts adverse outcomes and becomes common with age. There is recognition that sarcopenia may occur at younger ages in those with long‐term conditions (LTCs) as well as those with multimorbidity (the presence of two or more LTCs), but their relationships have been little explored. Our aims were to describe the prevalence of sarcopenia in UK Biobank, a large sample of men and women aged 40–70 years, and to explore relationships with different categories of LTCs and multimorbidity.
Methods
We used data from 499 046 participants in the baseline of UK Biobank. Our main outcome was probable sarcopenia based on maximum grip strength below sex‐specific cut‐points. Participants LTCs were recorded during an interview and categorized against a hierarchy. We used logistic regression to examine the independent associations between each category of LTCs and probable sarcopenia, including adjustment for age, sex, and body mass index. We also examined the association with multimorbidity.
Results
Probable sarcopenia had an overall prevalence of 5.3% and increased with age. The categories with the strongest associations with probable sarcopenia were musculoskeletal/trauma OR 2.17 (95% CI: 2.11, 2.23), endocrine/diabetes OR 1.49 (95% CI: 1.45, 1.55), and neurological/psychiatric OR 1.39 (95% CI: 1.34, 1.43) LTCs. Almost half of the sample (44.5%) had multimorbidity, and they were at nearly twice the odds of probable sarcopenia OR 1.96 (95% CI: 1.91, 2.02) compared with those without.
Conclusions
We have shown an overall prevalence of 5.3% of probable sarcopenia at ages 40–70 in UK Biobank. The risk of probable sarcopenia was higher in those with some categories of LTCs, suggesting that these groups may stand to benefit from assessment of sarcopenia, during mid‐life as well as old age.

Longitudinal serum biomarker screening identifies malate dehydrogenase 2 as candidate prognostic biomarker for Duchenne muscular dystrophy

27-12-2019 – Mirko Signorelli, Burcu Ayoglu, Camilla Johansson, Hanns Lochmüller, Volker Straub, Francesco Muntoni, Erik Niks, Roula Tsonaka, Anja Persson, Annemieke Aartsma‐Rus, Peter Nilsson, Cristina Al‐Khalili Szigyarto, Pietro Spitali

Journal Article

Abstract
Background
Duchenne muscular dystrophy (DMD) is a fatal disease for which no cure is available. Clinical trials have shown to be largely underpowered due to inter‐individual variability and noisy outcome measures. The availability of biomarkers able to anticipate clinical benefit is highly needed to improve clinical trial design and facilitate drug development.
Methods
In this study, we aimed to appraise the value of protein biomarkers to predict prognosis and monitor disease progression or treatment outcome in patients affected by DMD. We collected clinical data and 303 blood samples from 157 DMD patients in three clinical centres; 78 patients contributed multiple blood samples over time, with a median follow‐up time of 2 years. We employed linear mixed models to identify biomarkers that are associated with disease progression, wheelchair dependency, and treatment with corticosteroids and performed survival analysis to find biomarkers whose levels are associated with time to loss of ambulation.
Results
Our analysis led to the identification of 21 proteins whose levels significantly decrease with age and nine proteins whose levels significantly increase. Seven of these proteins are also differentially expressed in non‐ambulant patients, and three proteins are differentially expressed in patients treated with glucocorticosteroids. Treatment with corticosteroids was found to partly counteract the effect of disease progression on two biomarkers, namely, malate dehydrogenase 2 (MDH2, P = 0.0003) and ankyrin repeat domain 2 (P = 0.0005); however, patients treated with corticosteroids experienced a further reduction on collagen 1 serum levels (P = 0.0003), especially following administration of deflazacort. A time to event analysis allowed to further support the use of MDH2 as a prognostic biomarker as it was associated with an increased risk of wheelchair dependence (P = 0.0003). The obtained data support the prospective evaluation of the identified biomarkers in natural history and clinical trials as exploratory biomarkers.
Conclusions
We identified a number of serum biomarkers associated with disease progression, loss of ambulation, and treatment with corticosteroids. The identified biomarkers are promising candidate prognostic and surrogate biomarkers, which may support drug developers if confirmed in prospective studies. The serum levels of MDH2 are of particular interest, as they correlate with disease stage and response to treatment with corticosteroids, and are also associated with the risk of wheelchair dependency and pulmonary function.

Grip strength mediates the relationship between muscle mass and frailty

26-12-2019 – Yu‐Ri Choe, Ju‐Ri Jeong, Yeon‐Pyo Kim

Journal Article

Abstract
Background
Although sarcopenia and frailty are important diseases in geriatrics, few studies have investigated the association between the two diseases. Thus, this study aimed to examine the relationship between two components of sarcopenia (muscle mass and muscle function) and frailty.
Methods
In total, 997 Korean older adults (456 men and 541 women) were included in this cross‐sectional observational study. We used a polynomial linear regression analysis to obtain standardized sex, age, and height‐adjusted appendicular skeletal muscle mass (z
ASM), as well as to standardized sex, age, and height‐adjusted grip strength (z
GS). We then performed a causal mediation analysis to confirm the relationship between z
ASM and frailty.
Results
In both men and women, z
GS mediated the relationship between z
ASM and frailty (average causal mediation effect in men: −0.096 {−0.159 to −0.050}; in women: −0.053 {−0.098 to −0.010}). For every one‐point increase in z
GS score, the relative risk of a one‐point increase in frailty was reduced by 21% in men (e−0.238 = 0.788) and by 11% in women (e−0.113 = 0.893).
Conclusions
In this study on Korean older adults, muscle mass did not have a direct effect on frailty but had an indirect effect through altered muscle function.

Chronic heart failure with diabetes mellitus is characterized by a severe skeletal muscle pathology

21-12-2019 – Jack O. Garnham, Lee D. Roberts, Ever Espino‐Gonzalez, Anna Whitehead, Peter P. Swoboda, Aaron Koshy, John Gierula, Maria F. Paton, Richard M. Cubbon, Mark T. Kearney, Stuart Egginton, T. Scott Bowen, Klaus K. Witte

Journal Article

Abstract
Background
Patients with coexistent chronic heart failure (CHF) and diabetes mellitus (DM) demonstrate greater exercise limitation and worse prognosis compared with CHF patients without DM, even when corrected for cardiac dysfunction. Understanding the origins of symptoms in this subgroup may facilitate development of targeted treatments. We therefore characterized the skeletal muscle phenotype and its relationship to exercise limitation in patients with diabetic heart failure (D‐HF).
Methods
In one of the largest muscle sampling studies in a CHF population, pectoralis major biopsies were taken from age‐matched controls (n = 25), DM (n = 10), CHF (n = 52), and D‐HF (n = 28) patients. In situ mitochondrial function and reactive oxygen species, fibre morphology, capillarity, and gene expression analyses were performed and correlated to whole‐body exercise capacity.
Results
Mitochondrial respiration, content, coupling efficiency, and intrinsic function were lower in D‐HF patients compared with other groups (P < 0.05). A unique mitochondrial complex I dysfunction was present in D‐HF patients only (P < 0.05), which strongly correlated to exercise capacity (R2 = 0.64; P < 0.001). Mitochondrial impairments in D‐HF corresponded to higher levels of mitochondrial reactive oxygen species (P < 0.05) and lower gene expression of anti‐oxidative enzyme superoxide dismutase 2 (P < 0.05) and complex I subunit NDUFS1 (P < 0.05). D‐HF was also associated with severe fibre atrophy (P < 0.05) and reduced local fibre capillarity (P < 0.05).
Conclusions
Patients with D‐HF develop a specific skeletal muscle pathology, characterized by mitochondrial impairments, fibre atrophy, and derangements in the capillary network that are linked to exercise intolerance. These novel preliminary data support skeletal muscle as a potential therapeutic target for treating patients with D‐HF.

Characteristics of sarcopenia by European consensuses and a phenotype score

21-12-2019 – Il‐Young Jang, Eunju Lee, Heayon Lee, Hyungchul Park, Sunyoung Kim, Kwang‐il Kim, Hee‐Won Jung, Dae Hyun Kim

Journal Article

Abstract
Background
We aimed to assess the clinical characteristics of sarcopenia by the original and revised European Working Group on Sarcopenia in Older People (EWGSOP 1 and 2), and to propose a new sarcopenia phenotype score (SPS) to improve relevance of clinical outcomes.
Methods
Analyses were performed in 1408 older adults of the Aging Study of Pyeong
Chang Rural Area, a community‐based cohort in Korea. For sarcopenia definitions, we used EWGSOP 1, EWGSOP 2, and SPS, a new index counting number of abnormal domains among components of grip strength, gait speed, or muscle mass. Frailty status by the frailty index and the Cardiovascular Health Study frailty score was compared with sarcopenia measures. Prediction ability for composite outcome combining death and institutionalization due to functional decline was assessed among sarcopenia measures.
Results
Generally, sarcopenia spectrum by both EWGSOP 1 and 2 was associated with worse functional status in parameters of geriatric assessments. However, population who were considered as sarcopenic by EWGSOP 1, but not by EWGSOP 2, showed increased risk of composite outcome and worse frailty status, compared with people who were classified as not sarcopenic by both EWGSOP 1 and 2. With SPS, dose–response relationship was observed with both frailty status and outcome prediction. Prediction for composite outcome was better in SPS than in EWGSOP 2 classification.
Conclusions
A new SPS might be used to classify sarcopenic burden in older adults to resolve possible inconsistencies in phenotype correlation and outcome prediction of EWGSOP 2 criteria.

Uniform sarcolemmal dystrophin expression is required to prevent extracellular microRNA release and improve dystrophic pathology

17-12-2019 – Tirsa L.E. Westering, Yulia Lomonosova, Anna M.L. Coenen‐Stass, Corinne A. Betts, Amarjit Bhomra, Margriet Hulsker, Lucy E. Clark, Graham McClorey, Annemieke Aartsma‐Rus, Maaike Putten, Matthew J.A. Wood, Thomas C. Roberts

Journal Article

Abstract
Background
Duchenne muscular dystrophy (DMD) is a fatal muscle‐wasting disorder caused by genetic loss of dystrophin protein. Extracellular micro
RNAs (ex‐mi
RNAs) are putative, minimally invasive biomarkers of DMD. Specific ex‐mi
RNAs (e.g. mi
R‐1, mi
R‐133a, mi
R‐206, and mi
R‐483) are highly up‐regulated in the serum of DMD patients and dystrophic animal models and are restored to wild‐type levels following exon skipping‐mediated dystrophin rescue in mdx mice. As such, ex‐mi
RNAs are promising pharmacodynamic biomarkers of exon skipping efficacy. Here, we aimed to determine the degree to which ex‐mi
RNA levels reflect the underlying level of dystrophin protein expression in dystrophic muscle.
Methods
Candidate ex‐mi
RNA biomarker levels were investigated in mdx mice in which dystrophin was restored with peptide‐PMO (PPMO) exon skipping conjugates and in mdx‐XistΔhs mice that express variable amounts of dystrophin from birth as a consequence of skewed X‐chromosome inactivation. mi
RNA profiling was performed in mdx‐XistΔhs mice using the Fire
Plex methodology and key results validated by small RNA Taq
Man RT‐q
PCR. The muscles from each animal model were further characterized by dystrophin western blot and immunofluorescence staining.
Results
The restoration of ex‐myomi
R abundance observed following PPMO treatment was not recapitulated in the high dystrophin‐expressing mdx‐XistΔhs group, despite these animals expressing similar amounts of total dystrophin protein (~37% of wild‐type levels). Instead, ex‐mi
RNAs were present at high levels in mdx‐XistΔhs mice regardless of dystrophin expression. PPMO‐treated muscles exhibited a uniform pattern of dystrophin localization and were devoid of regenerating fibres, whereas mdx‐XistΔhs muscles showed non‐homogeneous dystrophin staining and sporadic regenerating foci.
Conclusions
Uniform dystrophin expression is required to prevent ex‐mi
RNA release, stabilize myofiber turnover, and attenuate pathology in dystrophic muscle.

Identification of microRNAs in skeletal muscle associated with lung cancer cachexia

11-12-2019 – Wouter R.P.H. Worp, Annemie M.W.J. Schols, Anne‐Marie C. Dingemans, Céline M.H. Op den Kamp, Juliette H.R.J. Degens, Marco C.J.M. Kelders, Susan Coort, Henry C. Woodruff, Gueorqui Kratassiouk, Annick Harel‐Bellan, Jan Theys, Ardy Helvoort, Ramon C.J. Langen

Journal Article

Abstract
Background
Cachexia, highly prevalent in patients with non‐small cell lung cancer (NSCLC), impairs quality of life and is associated with reduced tolerance and responsiveness to cancer therapy and decreased survival. Micro
RNAs (mi
RNAs) are small non‐coding RNAs that play a central role in post‐transcriptional gene regulation. Changes in intramuscular levels of mi
RNAs have been implicated in muscle wasting conditions. Here, we aimed to identify mi
RNAs that are differentially expressed in skeletal muscle of cachectic lung cancer patients to increase our understanding of cachexia and to allow us to probe their potential as therapeutic targets.
Methods
A total of 754 unique mi
RNAs were profiled and analysed in vastus lateralis muscle biopsies of newly diagnosed treatment‐naïve NSCLC patients with cachexia (n = 8) and age‐matched and sex‐matched healthy controls (n = 8). mi
RNA expression analysis was performed using a Taq
Man Micro
RNA Array. In silico network analysis was performed on all significant differentially expressed mi
RNAs. Differential expression of the top‐ranked mi
RNAs was confirmed using reverse transcription–quantitative real‐time PCR in an extended group (n = 48) consisting of NSCLC patients with (n = 15) and without cachexia (n = 11) and healthy controls (n = 22). Finally, these mi
RNAs were subjected to univariate and multivariate Cox proportional hazard analysis using overall survival and treatment‐induced toxicity data obtained during the follow‐up of this group of patients.
Results
We identified 28 significant differentially expressed mi
RNAs, of which five mi
RNAs were up‐regulated and 23 were down‐regulated. In silico mi
RNA‐target prediction analysis showed 158 functional gene targets, and pathway analysis identified 22 pathways related to the degenerative or regenerative processes of muscle tissue. Subsequently, the expression of six top‐ranked mi
RNAs was measured in muscle biopsies of the entire patient group. Five mi
RNAs were detectable with reverse transcription–quantitative real‐time PCR analysis, and their altered expression (expressed as fold change, FC) was confirmed in muscle of cachectic NSCLC patients compared with healthy control subjects: mi
R‐424‐5p (FC = 4.5), mi
R‐424‐3p (FC = 12), mi
R‐450a‐5p (FC = 8.6), mi
R‐144‐5p (FC = 0.59), and mi
R‐451a (FC = 0.57). In non‐cachectic NSCLC patients, only mi
R‐424‐3p was significantly increased (FC = 5.6) compared with control. Although the statistical support was not sufficient to imply these mi
RNAs as individual predictors of overall survival or treatment‐induced toxicity, when combined in multivariate analysis, mi
R‐450‐5p and mi
R‐451a resulted in a significant stratification between short‐term and long‐term survival.
Conclusions
We identified differentially expressed mi
RNAs putatively involved in lung cancer cachexia. These findings call for further studies to investigate the causality of these mi
RNAs in muscle atrophy and the mechanisms underlying their differential expression in lung cancer cachexia.

Inter‐individual variability in response to exercise intervention or usual care in hospitalized older adults

10-12-2019 – Mikel L. Sáez de Asteasu, Nicolás Martínez‐Velilla, Fabricio Zambom‐Ferraresi, Álvaro Casas‐Herrero, Eduardo L. Cadore, Robinson Ramirez‐Velez, Mikel Izquierdo

Journal Article

Abstract
Background
Exercise protocols applied during hospitalization can prevent functional and cognitive decline in older adults. The purpose of this study was to examine the individual response of acutely hospitalized patients to usual care and to physical exercise on functional capacity, muscle strength, and cognitive function and to assess the relationship with mortality at 1 year post‐discharge.
Methods
In a single‐blind randomized clinical trial, 370 hospitalized patients 56.5% women; mean age (standard deviation) 87.3 (4.9) years were allocated to an exercise intervention group (IG, n = 185) or a control group (CG, n = 185). The participants were older adults aged 75 years or older in an acute care unit in a tertiary public hospital in Navarra, Spain. The usual care group received habitual hospital care, which included physical rehabilitation when needed. The in‐hospital intervention included individualized multicomponent exercise training programme performed during 5–7 consecutive days (two sessions/day). Functional capacity was assessed with the Short Physical Performance Battery (SPPB) test and the Gait Velocity Test (GVT). Handgrip strength and cognitive function were also measured at admission and discharge. Patients in both groups were categorized as responders (Rs), non‐responders (NRs), and adverse responders (ARs) based on the individual response to each treatment during hospitalization.
Results
The prevalence of Rs was higher and the prevalence of NRs and ARs was lower in the intervention group than in the control group for functional capacity (SPPB IG: Rs 85.3%, NRs 8.7%, ARs 6.0% vs. CG: Rs 37.9%, NRs 28.8%, ARs 33.3% and GVT IG: Rs 51.2%, NRs 47.3, ARs 1.6% vs. CG: Rs 18.0%, NRs 67.7%, ARs 14.3%), muscle strength (IG: Rs 62.3%, NRs 26.5%, ARs 11.3% vs. CG: Rs 20.0%, NRs 38.0%, ARs 42.0%), and cognition (IG: Rs 41.5%, NRs 57.1%, ARs 1.4% vs. CG: Rs 13.8%, NRs 76.6%, ARs 9.7%) (all P < 0.001). The ARs for the GVT in the control group and the ARs for the SPPB in the intervention group had a significantly higher rate of mortality than the NRs and Rs in the equivalent groups (0.01 and 0.03, respectively) at follow‐up.
Conclusions
Older patients performing an individualized exercise intervention presented higher prevalence of Rs and a lower prevalence of NRs and ARs for functional capacity, muscle strength, and cognitive function than those who were treated with usual care during acute hospitalization. An adverse response on functional capacity in older patients to physical exercise or usual care during hospitalization was associated with mortality at 1 year post‐discharge.

Weight loss in heart failure is associated with increased mortality only in non‐obese patients without diabetes

10-12-2019 – Jacek T. Niedziela, Bartosz Hudzik, Krzysztof Strojek, Lech Poloński, Mariusz Gąsior, Piotr Rozentryt

Journal Article

Abstract
Background
Weight loss (WL) is an independent predictor of mortality in patients with heart failure (HF). Moderate WL is recommended for overweight or obese patients with type 2 diabetes mellitus (DM). The aim of this study was to assess the prognostic impact of body weight reduction on survival in patients with both HF with reduced ejection fraction (HFr
EF) and DM.
Methods
The study comprised patients with HFr
EF at the outpatient clinic. WL was defined as a body weight reduction of at least 7.5% during at least 6 months. Clinical features and 1 year mortality were analysed in WL and DM groups. Multivariate regression model was chosen to assess the predictive role of WL in HF patients with and without DM. The analysis regarding obesity before HF was also performed.
Results
The study comprised 777 patients with HFr
EF. Mean age was 53.2 ± 9.2, 12.0% were women, mean EF was 23.7 ± 6.0 %, and New York Heart Association III or IV class, DM, and WL were found in 60.5%, 33.3%, and 47.1% patients, respectively. WL was more prevalent in diabetic patients, comparing with those without DM (53.7% vs. 43.8%, respectively, 0.01), and was associated with higher 1 year mortality only in non‐diabetic group (17.6% for WL vs. 8.2% for non‐WL, log‐rank 0.001). In the multivariate analysis, WL was associated with a higher risk of 1 year mortality in non‐diabetic patients: HR 1.76 (1.05–2.95), 0.03 and only in the subgroup without obesity: HR 2.35 (1.28–4.32), 0.006. In non‐diabetic patients with obesity and in diabetic patients regardless of weight status, WL was not associated with worse prognosis (thereof, WL was excluded from the multivariate models).
Conclusions
Overall, WL in HFr
EF has emerged as a predictor of unfavourable outcomes only in non‐obese patients without DM. More importantly, this study has identified that the presence of DM (irrespective of weight status) or the presence of obesity in non‐diabetic patients abolished the unfavourable impact of WL on long‐term outcomes.

Testosterone therapy induces molecular programming augmenting physiological adaptations to resistance exercise in older men

10-12-2019 – Nima Gharahdaghi, Supreeth Rudrappa, Matthew S. Brook, Iskandar Idris, Hannah Crossland, Claire Hamrock, Muhammad Hariz Abdul Aziz, Fawzi Kadi, Janelle Tarum, Paul L. Greenhaff, Dumitru Constantin‐Teodosiu, Jessica Cegielski, Bethan E. Phillips, Daniel J. Wilkinson, Nathaniel J. Szewczyk, Kenneth Smith, Philip J. Atherton

Journal Article

Abstract
Background
The andropause is associated with declines in serum testosterone (T), loss of muscle mass (sarcopenia), and frailty. Two major interventions purported to offset sarcopenia are anabolic steroid therapies and resistance exercise training (RET). Nonetheless, the efficacy and physiological and molecular impacts of T therapy adjuvant to short‐term RET remain poorly defined.
Methods
Eighteen non‐hypogonadal healthy older men, 65–75 years, were assigned in a random double‐blinded fashion to receive, biweekly, either placebo (P, saline, n = 9) or T (Sustanon 250 mg, n = 9) injections over 6 week whole‐body RET (three sets of 8–10 repetitions at 80% one‐repetition maximum). Subjects underwent dual‐energy X‐ray absorptiometry, ultrasound of vastus lateralis (VL) muscle architecture, and knee extensor isometric muscle force tests; VL muscle biopsies were taken to quantify myogenic/anabolic gene expression, anabolic signalling, muscle protein synthesis (D2O), and breakdown (extrapolated).
Results
Testosterone adjuvant to RET augmented total fat‐free mass (P=0.007), legs fat‐free mass (P=0.02), and appendicular fat‐free mass (P=0.001) gains while decreasing total fat mass (P=0.02). Augmentations in VL muscle thickness, fascicle length, and quadriceps cross‐section area with RET occured to a greater extent in T (P < 0.05). Sum strength (P=0.0009) and maximal voluntary contract (e.g. knee extension at 70°) (P=0.002) increased significantly more in the T group. Mechanistically, both muscle protein synthesis rates (T: 2.13 ± 0.21%·day−1 vs. P: 1.34 ± 0.13%·day−1, P=0.0009) and absolute breakdown rates (T: 140.2 ± 15.8 g·day−1 vs. P: 90.2 ± 11.7 g·day−1, P=0.02) were elevated with T therapy, which led to higher net turnover and protein accretion in the T group (T: 8.3 ± 1.4 g·day−1 vs. P: 1.9 ± 1.2 g·day−1, P=0.004). Increases in ribosomal biogenesis (RNA:DNA ratio); m
RNA expression relating to T metabolism (androgen receptor: 1.4‐fold; Srd5a1: 1.6‐fold; AKR1C3: 2.1‐fold; and HSD17β3: two‐fold); insulin‐like growth factor (IGF)‐1 signalling IGF‐1Ea (3.5‐fold) and IGF‐1Ec (three‐fold) and myogenic regulatory factors; and the activity of anabolic signalling (e.g. m
TOR, AKT, and RPS6; P < 0.05) were all up‐regulated with T therapy. Only T up‐regulated mitochondrial citrate synthase activity (P=0.03) and transcription factor A (1.41 ± 0.2‐fold, P=0.0002), in addition to peroxisome proliferator‐activated receptor‐γ co‐activator 1‐α m
RNA (1.19 ± 0.21‐fold, P=0.037).
Conclusions
Administration of T adjuvant to RET enhanced skeletal muscle mass and performance, while up‐regulating myogenic gene programming, myocellular translational efficiency and capacity, collectively resulting in higher protein turnover, and net protein accretion. T coupled with RET is an effective short‐term intervention to improve muscle mass/function in older non‐hypogonadal men.

Associations between severe co‐morbidity and muscle measures in advanced non‐small cell lung cancer patients

10-12-2019 – Bjørn H. Grønberg, Christine Damgaard Valan, Tarje Halvorsen, Bjørg Sjøblom, Marit S. Jordhøy

Journal Article

Abstract
Background
Studies show that low skeletal muscle index (SMI) and low skeletal muscle density (SMD) are negative prognostic factors and associated with more toxicity from systemic therapy in cancer patients. However, muscle depletion can be caused by a range of diseases, and many cancer patients have significant co‐morbidity. The aim of this study was to investigate whether there were associations between co‐morbidity and muscle measures in patients with advanced non‐small cell lung cancer.
Methods
Patients in a Phase III trial comparing two chemotherapy regimens in advanced non‐small cell lung cancer were analysed (n = 436). Co‐morbidity was assessed using the Cumulative Illness Rating Scale for Geriatrics (CIRS‐G), which rates co‐morbidity from 0 to 4 on 14 different organ scales. Severe co‐morbidity was defined as having any grades 3 and 4 CIRS‐G score. Muscle measures were assessed from baseline computed tomography slides at the L3 level using the Slice
OMatic software.
Results
Complete data were available for 263 patients (60%). Median age was 66, 57.0% were men, 78.7% had performance status 0–1, 25.9% Stage IIIB, 11.4% appetite loss, 92.4% were current/former smokers, 22.8% were underweight, 43.7% had normal weight, 26.6% were overweight, and 6.8% obese. The median total CIRS‐G score was 7 (range: 0–16), and 48.2% had severe co‐morbidity. Mean SMI was 44.7 cm2/m2 (range: 27–71), and the mean SMD was 37.3 Hounsfield units (HU) (range: 16–60). When comparing patients with and without severe co‐morbidity, there were no significant differences in median SMI (44.5 vs. 44.1 cm2/m2; 0.70), but patients with severe co‐morbidity had a significantly lower median SMD (36 HU vs. 39 HU; 0.001), mainly due to a significant difference in SMD between those with severe heart disease and those without (32.5 vs. 37.9 HU; 0.002). Linear regression analyses confirmed the association between severe co‐morbidity and SMD both in the simple analysis (0.001) and the multiple analysis (0.037) adjusting for baseline characteristics. Stage of disease, gender, and body mass index (BMI) were significantly associated with SMI in both the simple and multiple analyses. Age and BMI were significantly associated with SMD in the simple analysis; and age, gender, and BMI were significantly associated in the multiple analysis.
Conclusions
There were no significant differences in SMI between patients with and patients without severe co‐morbidity, but patients with severe co‐morbidity had lower SMD than other patients, mainly due to severe heart disease. Co‐morbidity might be a confounder in studies of the clinical role of SMD in cancer patients.

The Copenhagen Sarcopenia Study: lean mass, strength, power, and physical function in a Danish cohort aged 20–93 years

10-12-2019 – Charlotte Suetta, Bryan Haddock, Julian Alcazar, Tim Noerst, Ole M. Hansen, Helle Ludvig, Rikke Stefan Kamper, Peter Schnohr, Eva Prescott, Lars L. Andersen, Ulrik Frandsen, Per Aagaard, Jens Bülow, Peter Hovind, Lene Simonsen

Journal Article

Abstract
Background
Despite no international consensus on the diagnostic criteria for sarcopenia, low lean mass, muscle strength, and physical function are important risk factors for disability, frailty, and mortality in older individuals, as well as in a wide range of patients with muscle loss. Here, we provide a population‐based reference material of total and regional lean body mass, muscle strength/power parameters, and physical function in a healthy cohort of Danish men and women across the lifespan.
Methods
Volunteers aged 20–93 years from the Copenhagen City Heart Study were invited to establish a Danish reference material (Copenhagen Sarcopenia Study) on lean mass characteristics appendicular lean mass (ALM), i
DXA, GE Lunar, muscle function handgrip strength (HGS), Jamar dynamometer and leg extension power (LEP), Nottingham Power Rig, and physical function 30 s sit‐to‐stand test (STS), 10‐m maximal and habitual gait speed (GS).
Results
A total of 1305 participants 729 women (age: 56.4 ± 18.9 years, height: 1.66 ± 0.01 m, body mass index: 24.6 ± 4.3 kg/m2 and 576 men, age: 57.0 ± 17.5 years, height: 1.80 ± 0.07 m, body mass index: 26.0 ± 3.9 kg/m2 completed all measurements and were included in the present analysis. Lean mass characteristics (TLM, ALM, and ALM/h2) decreased with increasing age in both men and women (P < 0.001). Men demonstrated larger absolute and relative total ALM and higher HGS and LEP compared with women at all age intervals (P < 0.001). HGS and LEP decreased progressively with age in both men and women (P < 0.01); 30 s STS performance, habitual GS, and maximal GS decreased at an accellerated rate of decline with increasing age in both men and women (P < 0.001). Habitual GS was reduced in men and women aged ≥70 years, while maximal GS was reduced from the age of ≥60 years compared with young adults (P < 0.001). Regardless of sex, 30 s STS was reduced from the age of ≥50 years compared with the young reference group (P < 0.001)Conclusions
While the power‐based measurements (LEP and 30 s STS) started to decline already at age +50 years, less power‐based parameters (GS and HGS) and lean mass characteristics (TLM, ALM, and ALM/h2) remained unaltered until after the age of +70 years. Notably, the cut‐off thresholds derived in the present study differed from earlier reference data, which underlines the importance of obtaining updated and local reference materials.

Mice with myocyte deletion of vitamin D receptor have sarcopenia and impaired muscle function

10-12-2019 – Christian M. Girgis, Kuan Minn Cha, Benjamin So, Michael Tsang, Jennifer Chen, Peter J. Houweling, Aaron Schindeler, Rebecca Stokes, Michael M. Swarbrick, Frances J. Evesson, Sandra T. Cooper, Jenny E. Gunton

Journal Article

Abstract
Background
It has long been recognized that vitamin D deficiency is associated with muscle weakness and falls. Vitamin D receptor (VDR) is present at very low levels in normal muscle. Whether vitamin D plays a direct role in muscle function is unknown and is a subject of hot debate. Myocyte‐specific deletion of VDR would provide a strategy to answer this question.
Methods
Myocyte‐specific vitamin D receptor (m
VDR) null mice were generated by crossing human skeletal actin‐Cre mice with floxed VDR mice. The effects of gene deletion on the muscle phenotype were studied in terms of body tissue composition, muscle tissue histology, and gene expression by real‐time PCR.
Results
Unlike whole‐body VDR knockout mice, m
VDR mice showed a normal body size. The m
VDR showed a distinct muscle phenotype featuring reduced proportional lean mass (70% vs. 78% of lean mass), reduced voluntary wheel‐running distance (22% decrease, P = 0.009), reduced average running speed, and reduced grip strength (7–16% reduction depending on age at testing). With their decreased voluntary exercise, and decreased lean mass, m
VDR have increased proportional fat mass at 20% compared with 13%.
Surprisingly, their muscle fibres showed slightly increased diameter, as well as the presence of angular fibres and central nuclei suggesting ongoing remodelling. There were, however, no clear changes in fibre type and there was no increase in muscle fibrosis. VDR is a transcriptional regulator, and changes in the expression of candidate genes was examined in RNA extracted from skeletal muscle. Alterations were seen in myogenic gene expression, and there was decreased expression of cell cycle genes cyclin D1, D2, and D3 and cyclin‐dependent kinases Cdk‐2 and Cdk‐4. Expression of calcium handling genes sarcoplasmic/endoplasmic reticulum calcium ATPases (SERCA) Serca2b and Serca3 was decreased and Calbindin m
RNA was lower in m
VDR muscle.
Conclusions
This study demonstrates that vitamin D signalling is needed for myocyte function. Despite the low level of VDR protein normally found muscle, deleting myocyte VDR had important effects on muscle size and strength. Maintenance of normal vitamin D signalling is a useful strategy to prevent loss of muscle function and size.

Signal regulatory protein alpha initiates cachexia through muscle to adipose tissue crosstalk

10-12-2019 – Jiao Wu, Jiangling Dong, Daniela Verzola, Keith Hruska, Giacomo Garibotto, Zhaoyong Hu, William E. Mitch, Sandhya S. Thomas

Journal Article

Abstract
Background
Muscle wasting from chronic kidney disease (CKD) or from defective insulin signalling results in morbidity and, ultimately, mortality. We have identified an endogenous mediator of insulin resistance, signal regulatory protein alpha (SIRPα), which leads to cachexia in mice and is associated with cachexia in patients with CKD.
Methods
We assessed insulin signalling and mechanisms causing muscle atrophy plus white adipose tissue (WAT) metabolism in mouse models of CKD or acute diabetes (streptozotocin treatment). We then examined these factors in mice with global knockout (KO) of SIRPα and sought mediators of metabolic responses in muscle and adipose tissues of mice with either muscle‐specific or adipose tissue‐specific KO of SIRPα. Metabolic responses were confirmed in primary cultures of adipose cells.
Results
In mice with CKD, SIRPα expression was increased in WAT (three‐fold, P < 0.05), and this was associated with precursors of cachexia: ‘pathologic browning, thermogenesis, and a two‐fold activation of protein kinase A (P < 0.05 vs. control mice) plus loss of adipose tissue mass. In contrast, mice with SIRPα global KO and CKD or acute diabetes experienced improved insulin signalling and activation of p
Akt plus ‘physiologic browning of WAT. These mice avoided losses of muscle and adipose tissues and experienced a 31% improvement in survival (P < 0.05) than did wild‐type mice with CKD. In muscle‐specific SIRPα KO mice with CKD, we uncovered that serum SIRPα levels (P < 0.05) were suppressed and were associated with improved insulin signalling both in skeletal muscles and in WAT. These changes were accompanied by physiologic WAT browning. However, in adipose‐specific SIRPα KO mice with CKD, levels of serum SIRPα were increased over two‐fold (P < 0.05), while muscle losses were minimally inhibited. Clinical implications of SIRPα signalling are suggested by our findings that include increased SIRPα expression in muscle and adipose tissues (P < 0.05 vs. healthy controls) plus higher SIRPα levels in the serum of patients with CKD (2.4‐fold, P=0.000017 vs. healthy controls).
Conclusions
Our results show that SIRPα plays an important role as an anti‐insulin mediator regulating pathways to cachexia. In muscle‐specific SIRPα KO, changes in SIRPα serum levels seem to improve insulin signalling in muscle and WAT, suggesting crosstalk between muscle and adipose tissue. Therefore, targeting SIRPα may prevent cachexia in patients with CKD or acute diabetes.

Muscle‐specific changes in protein synthesis with aging and reloading after disuse atrophy

10-12-2019 – Benjamin F. Miller, Leslie M. Baehr, Robert V. Musci, Justin J. Reid, Frederick F. Peelor, Karyn L. Hamilton, Sue C. Bodine

Journal Article

Abstract
Background
Successful strategies to halt or reverse sarcopenia require a basic understanding of the factors that cause muscle loss with age. Acute periods of muscle loss in older individuals have an incomplete recovery of muscle mass and strength, thus accelerating sarcopenic progression. The purpose of the current study was to further understand the mechanisms underlying the failure of old animals to completely recover muscle mass and function after a period of hindlimb unloading.
Methods
Hindlimb unloading was used to induce muscle atrophy in Fischer 344–Brown Norway (F344BN F1) rats at 24, 28, and 30 months of age. Rats were hindlimb unloaded for 14 days and then reloaded at 24 months (Reloaded 24), 28 months (Reloaded 28), and 24 and 28 months (Reloaded 24/28) of age. Isometric torque was determined at 24 months of age (24 months), at 28 months of age (28 months), immediately after 14 days of reloading, and at 30 months of age (30 months). During control or reloaded conditions, rats were labelled with deuterium oxide (D2O) to determine rates of muscle protein synthesis and RNA synthesis.
Results
After 14 days of reloading, in vivo isometric torque returned to baseline in Reloaded 24, but not Reloaded 28 and Reloaded 24/28. Despite the failure of Reloaded 28 and Reloaded 24/28 to regain peak force, all groups were equally depressed in peak force generation at 30 months. Increased age did not decrease muscle protein synthesis rates, and in fact, increased resting rates of protein synthesis were measured in the myofibrillar fraction (Fractional synthesis rate (FSR): %/day) of the plantaris (24 months: 2.53 ± 0.17; 30 months: 3.29 ± 0.17), and in the myofibrillar (24 months: 2.29 ± 0.07; 30 months: 3.34 ± 0.11), collagen (24 months: 1.11 ± 0.07; 30 months: 1.55 ± 0.14), and mitochondrial (24 months: 2.38 ± 0.16; 30 months: 3.20 ± 0.10) fractions of the tibialis anterior (TA). All muscles increased myofibrillar protein synthesis (%/day) in Reloaded 24 (soleus: 3.36 ± 0.11, 5.23 ± 0.19; plantaris: 2.53 ± 0.17, 3.66 ± 0.07; TA: 2.29 ± 0.14, 3.15 ± 0.12); however, in Reloaded 28, only the soleus had myofibrillar protein synthesis rates (%/day) >28 months (28 months: 3.80 ± 0.10; Reloaded 28: 4.86 ± 0.19). Across the muscles, rates of protein synthesis were correlated with RNA synthesis (all muscles combined, R2 = 0.807, P < 0.0001).
Conclusions
These data add to the growing body of literature that indicate that changes with age, including following disuse atrophy, differ by muscle. In addition, our findings lead to additional questions of the underlying mechanisms by which some muscles are maintained with age while others are not.

Tracking muscle wasting and disease activity in facioscapulohumeral muscular dystrophy by qualitative longitudinal imaging

10-12-2019 – Mauro Monforte, Francesco Laschena, Pierfrancesco Ottaviani, Maria Rosaria Bagnato, Anna Pichiecchio, Giorgio Tasca, Enzo Ricci

Journal Article

Abstract
Background
Facioscapulohumeral muscular dystrophy (FSHD) is one of the most frequent late‐onset muscular dystrophies, characterized by progressive fatty replacement and degeneration involving single muscles in an asynchronous manner. With clinical trials at the horizon in this disease, the knowledge of its natural history is of paramount importance to understand the impact of new therapies. The aim of this study was to assess disease progression in FSHD using qualitative muscle magnetic resonance imaging, with a focus on the evolution of hyperintense lesions identified on short‐tau inversion recovery (STIR+) sequences, hypothesized to be markers of active muscle injury.
Methods
One hundred genetically confirmed consecutive FSHD patients underwent lower limb muscle magnetic resonance imaging at baseline and after 365 ± 60 days in this prospective longitudinal study. T1 weighted (T1w) and STIR sequences were used to assess fatty replacement using a semiquantitative visual score and muscle oedema. The baseline and follow‐up scans of each patient were also evaluated by unblinded direct comparison to detect the changes not captured by the scoring system.
Results
Forty‐nine patients showed progression on T1w sequences after 1 year, and 30 patients showed at least one new STIR+ lesion. Increased fat deposition at follow‐up was observed in 13.9% STIR+ and in only 0.21% STIR‐ muscles at baseline (P < 0.001). Overall, 89.9% of the muscles that showed increased fatty replacement were STIR+ at baseline and 7.8% were STIR+ at 12 months. A higher number of STIR+ muscles at baseline was associated with radiological worsening (odds ratio 1.17, 95% confidence interval 1.06–1.30, P = 0.003).
Conclusions
Our study confirms that STIR+ lesions represent prognostic biomarkers in FSHD and contributes to delineate its radiological natural history, providing useful information for clinical trial design. Given the peculiar muscle‐by‐muscle involvement in FSHD, MRI represents an invaluable tool to explore the modalities and rate of disease progression.

Mechanisms involved in follistatin‐induced hypertrophy and increased insulin action in skeletal muscle

10-12-2019 – Xiuqing Han, Lisbeth Liliendal Valbjørn Møller, Estelle De Groote, Kirstine Nyvold Bojsen‐Møller, Jonathan Davey, Carlos Henríquez‐Olguin, Zhencheng Li, Jonas Roland Knudsen, Thomas Elbenhardt Jensen, Sten Madsbad, Paul Gregorevic, Erik Arne Richter, Lykke Sylow

Journal Article

Abstract
Background
Skeletal muscle wasting is often associated with insulin resistance. A major regulator of muscle mass is the transforming growth factor β (TGF‐β) superfamily, including activin A, which causes atrophy. TGF‐β superfamily ligands also negatively regulate insulin‐sensitive proteins, but whether this pathway contributes to insulin action remains to be determined.
Methods
To elucidate if TGF‐β superfamily ligands regulate insulin action, we used an adeno‐associated virus gene editing approach to overexpress an activin A inhibitor, follistatin (Fst288), in mouse muscle of lean and diet‐induced obese mice. We determined basal and insulin‐stimulated 2‐deoxy‐glucose uptake using isotopic tracers in vivo. Furthermore, to evaluate whether circulating Fst and activin A concentrations are associated with obesity, insulin resistance, and weight loss in humans, we analysed serum from morbidly obese subjects before, 1 week, and 1 year after Roux‐en‐Y gastric bypass (RYGB).
Results
Fst288 muscle overexpression markedly increased in vivo insulin‐stimulated (but not basal) glucose uptake (+75%, P < 0.05) and increased protein expression and intracellular insulin signalling of AKT, TBC1D4, PAK1, pyruvate dehydrogenase‐E1α, and p70S6K, while decreasing TBC1D1 signaling (P < 0.05). Fst288 increased both basal and insulin‐stimulated protein synthesis, but no correlation was observed between the Fst288‐driven hypertrophy and the increase in insulin‐stimulated glucose uptake. Importantly, Fst288 completely normalized muscle glucose uptake in insulin‐resistant diet‐induced obese mice. RYGB surgery doubled circulating Fst and reduced activin A (−24%, P < 0.05) concentration 1 week after surgery before any significant weight loss in morbidly obese normoglycemic patients, while major weight loss after 1 year did not further change the concentrations.
Conclusions
We here present evidence that Fst is a potent regulator of insulin action in muscle, and in addition to AKT and p70S6K, we identify TBC1D1, TBC1D4, pyruvate dehydrogenase‐E1α, and PAK1 as Fst targets. Circulating Fst more than doubled post‐RYGB surgery, a treatment that markedly improved insulin sensitivity, suggesting a role for Fst in regulating glycaemic control. These findings demonstrate the therapeutic potential of inhibiting TGF‐β superfamily ligands to improve insulin action and Fsts relevance to muscle wasting‐associated insulin‐resistant conditions in mice and humans.

Differentially methylated gene patterns between age‐matched sarcopenic and non‐sarcopenic women

10-12-2019 – Lingxiao He, Praval Khanal, Christopher I. Morse, Alun Williams, Martine Thomis

Journal Article

Abstract
Background
Sarcopenia is characterized by progressive decreases in muscle mass, muscle strength, and muscle function with ageing. Although many studies have investigated the mechanisms of sarcopenia, its connection with epigenetic factors, such as DNA methylation, still remains poorly understood. The aim of this study was to explore sarcopenia‐related DNA methylation differences in blood samples between age‐matched sarcopenic and non‐sarcopenic older women.
Methods
A sarcopenic group (n = 24) was identified and selected from a set of 247 older Caucasian women (aged 65–80 years) based on cut‐off points of skeletal muscle index at 6.75 kg/m2 and grip strength at 26 kg (the lower quintile of grip strength in the set). A non‐sarcopenic group (n = 24) was created with a similar age distribution as that of the sarcopenic group. DNA methylation patterns of whole blood samples from both groups were analysed using Infinium Methylation
EPIC Bead
Chip arrays. Differentially methylated cytosin–phosphate–guanine sites (dm
Cp
Gs) were identified at a P value threshold of 0.01 by comparing methylation levels between the sarcopenic and non‐sarcopenic groups at each Cp
G site. dm
Cp
G‐related genes were annotated based on Homo sapiens hg19 genome build. The functions of these genes were further examined by GO and KEGG pathway enrichment analysis.
Results
The global methylation level of all analysed Cp
G sites (n = 788 074) showed no significant difference between the sarcopenic and non‐sarcopenic groups (0.812), while the average methylation level of dm
Cp
Gs (n = 6258) was significantly lower in the sarcopenic group (0.004). The sarcopenic group had significantly higher methylation levels in TSS200 (the region from transcription start site to 200 nucleotides upstream of the site) and lower methylation levels in gene body and 3UTR regions. In respect of Cp
G regions, Cp
G islands in promoters and some intragenic regions showed greater levels of methylation in the sarcopenic group. dm
Cp
G‐related KEGG pathways were mainly associated with muscle function, actin cytoskeleton regulation, and energy metabolism. Seven genes (HSPB1, PBX4, CNKSR3, ORMDL3, MIR10A, ZNF619, and CRADD) were found with the same methylation direction as previous studies of blood sample methylation during ageing. Fifty‐four genes were shared with previous studies of resistance training.
Conclusions
Our results improve understanding of epigenetic mechanisms of sarcopenia by identifying sarcopenia‐related DNA methylation differences in blood samples of older women. These methylation differences suggest underlying alterations of gene expression and pathway function, which can partially explain sarcopenia‐related muscular changes.

Associations of fat‐soluble micronutrients and redox biomarkers with frailty status in the FRAILOMIC initiative

10-12-2019 – Bastian Kochlik, Wolfgang Stuetz, Karine Pérès, Sophie Pilleron, Catherine Féart, Francisco José García García, Stefania Bandinelli, David Gomez‐Cabrero, Leocadio Rodriguez‐Mañas, Tilman Grune, Daniela Weber

Journal Article

Abstract
Background
A poor fat‐soluble micronutrient (FMN) and a high oxidative stress status are associated with frailty. Our aim was to determine the cross‐sectional association of FMNs and oxidative stress biomarkers protein carbonyls (Pr
Carb) and 3‐nitrotyrosine with the frailty status in participants older than 65 years.
Methods
Plasma levels of vitamins A (retinol), D3, E (α‐tocopherol and γ‐tocopherol) and carotenoids (α‐carotene and β‐carotene, lycopene, lutein/zeaxanthin, and β‐cryptoxanthin), Pr
Carb, and 3‐nitrotyrosine were measured in 1450 individuals of the FRAILOMIC initiative. Participants were classified into robust, pre‐frail, and frail using Frieds frailty criteria. Associations between biomarkers and frailty status were assessed by general linear and logistic regression models, both adjusted for cohort, season of blood sampling, gender, age, height, weight, and smoking.
Results
Robust participants had significantly higher vitamin D3 and lutein/zeaxanthin concentrations than pre‐frail and frail subjects; had significantly higher γ‐tocopherol, α‐carotene, β‐carotene, lycopene, and β‐cryptoxanthin concentrations than frail subjects, and had significantly lower Pr
Carb concentrations than frail participants in multivariate linear models. Frail subjects were more likely to be in the lowest than in the highest tertile for vitamin D3 (adjusted odds ratio: 2.15; 95% confidence interval: 1.42–3.26), α‐tocopherol (2.12; 1.39–3.24), α‐carotene (1.69; 1.00–2.88), β‐carotene (1.84; 1.13–2.99), lycopene (1.94; 1.24–3.05), lutein/zeaxanthin (3.60; 2.34–5.53), and β‐cryptoxanthin (3.02; 1.95–4.69) and were more likely to be in the highest than in the lowest tertile for Pr
Carb (2.86; 1.82–4.49) than robust subjects in multivariate regression models.
Conclusions
Our study indicates that both low FMN and high Pr
Carb concentrations are associated with pre‐frailty and frailty.

The prognostic significance of weight loss in chronic obstructive pulmonary disease‐related cachexia: a prospective cohort study

10-12-2019 – Hoi Yee Kwan, Matthew Maddocks, Claire M. Nolan, Sarah E. Jones, Suhani Patel, Ruth E. Barker, Samantha S.C. Kon, Michael I. Polkey, Paul Cullinan, William D.‐C. Man

Journal Article

Abstract
Background
Cachexia is an important extra‐pulmonary manifestation of chronic obstructive pulmonary disease (COPD) presenting as unintentional weight loss and altered body composition. Previous studies have focused on the relative importance of body composition compared with body mass rather than the relative importance of dynamic compared with static measures. We aimed to determine the prevalence of cachexia and pre‐cachexia phenotypes in COPD and examine the associations between cachexia and its component features with all‐cause mortality.
Methods
We enrolled 1755 consecutive outpatients with stable COPD from two London centres between 2012 and 2017, stratified according to European Respiratory Society Task Force defined cachexia unintentional weight loss >5% and low fat‐free mass index (FFMI), pre‐cachexia (weight loss >5% but preserved FFMI), or no cachexia. The primary outcome was all‐cause mortality. We calculated hazard ratios (HRs) using Cox proportional hazards regression for cachexia classifications (cachexia, pre‐cachexia, and no cachexia) and component features (weight loss and FFMI) and mortality, adjusting for age, sex, body mass index, and disease‐specific prognostic markers.
Results
The prevalence of cachexia was 4.6% 95% confidence interval (CI): 3.6–5.6 and pre‐cachexia 1.6% (95% CI: 1.0–2.2). Prevalence was similar across sexes but increased with worsening Global Initiative for Chronic Obstructive Pulmonary Disease spirometric stage and Medical Research Council dyspnoea score (all P < 0.001). There were 313 (17.8%) deaths over a median (interquartile range) follow‐up duration 1089 (547–1704) days. Both cachexia HR 1.98 (95% CI: 1.31–2.99), P = 0.002 and pre‐cachexia HR 2.79 (95% CI: 1.48–5.29), P = 0.001 were associated with increased mortality. In multivariable analysis, the unintentional weight loss feature of cachexia was independently associated with mortality HR 2.16 (95% CI: 1.31–3.08), P < 0.001, whereas low FFMI was not HR 0.88 (95% CI: 0.64–1.20), P = 0.402. Sensitivity analyses using body mass index‐specific, age‐specific, and gender‐specific low FFMI values found consistent findings.
Conclusions
Despite the low prevalence of cachexia and pre‐cachexia, both confer increased mortality risk in COPD, driven by the unintentional weight loss component. Our data suggest that low FFMI without concurrent weight loss may not confer the poor prognosis as previously reported for this group. Weight loss should be regularly monitored in practice and may represent an important target in COPD management. We propose the incorporation of weight monitoring into national and international COPD guidance.

Clinical and biological characterization of skeletal muscle tissue biopsies of surgical cancer patients

10-12-2019 – Ana Anoveros‐Barrera, Amritpal S. Bhullar, Cynthia Stretch, Nina Esfandiari, Abha R. Dunichand‐Hoedl, Karen J.B. Martins, David Bigam, Rachel G. Khadaroo, Todd McMullen, Oliver F. Bathe, Sambasivarao Damaraju, Richard J. Skipworth, Charles T. Putman, Vickie E. Baracos, Vera C. Mazurak

Journal Article

Abstract
Background
Researchers increasingly use intraoperative muscle biopsy to investigate mechanisms of skeletal muscle atrophy in patients with cancer. Muscles have been assessed for morphological, cellular, and biochemical features. The aim of this study was to conduct a state‐of‐the‐science review of this literature and, secondly, to evaluate clinical and biological variation in biopsies of rectus abdominis (RA) muscle from a cohort of patients with malignancies.
Methods
Literature was searched for reports on muscle biopsies from patients with a cancer diagnosis. Quality of reports and risk of bias were assessed. Data abstracted included patient characteristics and diagnoses, sample size, tissue collection and biobanking procedures, and results. A cohort of cancer patients (n = 190, 88% gastrointestinal malignancies), who underwent open abdominal surgery as part of their clinical care, consented to RA biopsy from the site of incision. Computed tomography (CT) scans were used to quantify total abdominal muscle and RA cross‐sectional areas and radiodensity. Biopsies were assessed for muscle fibre area (μm2), fibre types, myosin heavy chain isoforms, and expression of genes selected for their involvement in catabolic pathways of muscle.
Results
Muscle biopsy occurred in 59 studies (total N = 1585 participants). RA was biopsied intraoperatively in 40 studies (67%), followed by quadriceps (26%; percutaneous biopsy) and other muscles (7%). Cancer site and stage, % of male participants, and age were highly variable between studies. Details regarding patient medical history and biopsy procedures were frequently absent. Lack of description of the population(s) sampled and low sample size contributed to low quality and risk of bias. Weight‐losing cases were compared with weight stable cancer or healthy controls without considering a measure of muscle mass in 21 out of 44 studies. In the cohort of patients providing biopsy for this study, 78% of patients had preoperative CT scans and a high proportion (64%) met published criteria for sarcopenia. Fibre type distribution in RA was type I (46% ± 13), hybrid type I/IIA (1% ± 1), type IIA (36% ± 10), hybrid type IIA/D (15% ± 14), and type IID (2% ± 5). Sexual dimorphism was prominent in RA CT cross‐sectional area, mean fibre cross‐sectional area, and in expression of genes associated with muscle growth, apoptosis, and inflammation (P < 0.05). Medical history revealed multiple co‐morbid conditions and medications.
Conclusions
Continued collaboration between researchers and cancer surgeons enables a more complete understanding of mechanisms of cancer‐associated muscle atrophy. Standardization of biobanking practices, tissue manipulation, patient characterization, and classification will enhance the consistency, reliability, and comparability of future studies.

Abstract

10-12-2019 –

The Journal of Cachexia, Sarcopenia and Muscle stays the front‐runner in geriatrics and gerontology

10-12-2019 – Markus S. Anker, Stefan D. Anker, Andrew J.S. Coats, Stephan Haehling

Editorial

With Appreciation

10-12-2019 –

Issue Information

10-12-2019 –

No abstract is available for this article.

Remarks on the design and analyses of longitudinal studies for cancer patients with anorexia and weight loss

10-12-2019 – Jennifer G. Le‐Rademacher, Elizabeth M. Storrick, Aminah Jatoi

Journal Article, Review

Abstract
Longitudinal data serve an important role in understanding the cancer anorexia weight loss syndrome and in testing interventions to palliative and treat patients who develop this syndrome. The element of time and the interrelatedness of data points define longitudinal data and add to the richness of this type of data. However, longitudinal data can also give rise to non‐random, missing data that can lead to flawed conclusions. This paper discusses these issues and suggests practical considerations for design and analysis of longitudinal cancer anorexia weight loss studies.

Metastasis and cachexia: alongside in clinics, but not so in animal models

10-12-2019 – Rebeka Tomasin, Ana Carolina Baptista Moreno Martin, Márcia Regina Cominetti

Journal Article, Review

Abstract
Cancer cachexia is a paraneoplastic syndrome characterized by lean mass wasting (with or without fat mass decrease), culminating in involuntary weight loss, which is the key clinical observation nowadays. There is a notable lack of studies involving animal models to mimic the clinical reality, which are mostly patients with cachexia and metastatic disease. This mismatch between the clinical reality and animal models could at least partly contribute to the poor translation observed in the field. In this paper, we retrieved and compared animal models used for cachexia research from 2017 and 10 years earlier (2007) and observed that very little has changed. Especially, clinically relevant models where cachexia is studied in an orthotopic or metastatic context were and still are very scarce. Finally, we described and supported the biological rationale behind why, despite technical challenges, these two phenomena—metastasis and cachexia—should be modelled in parallel, highlighting the overlapping pathways between them. To sum up, this review aims to contribute to rethinking and possibly switching the models currently used for cachexia research, to hopefully obtain better and more translational outcomes.

Sarcopenia and ovarian cancer survival: a systematic review and meta‐analysis

10-12-2019 – Jorne Ubachs, Janine Ziemons, Iris J.G. Minis‐Rutten, Roy F.P.M. Kruitwagen, Jos Kleijnen, Sandrina Lambrechts, Steven W.M. Olde Damink, Sander S. Rensen, Toon Van Gorp

Journal Article, Review

Abstract
Background
Sarcopenia is the loss of skeletal muscle mass and function that occurs with advancing age and certain diseases. It is thought to have a negative impact on survival in cancer patients. Routine computed tomography imaging is often used to quantify skeletal muscle in cancer patients. Sarcopenia is defined by a low skeletal muscle index (SMI). Skeletal muscle radiation attenuation (SMRA) is used to define muscle quality. The primary aim of this meta‐analysis was to study the association between sarcopenia or SMRA and overall survival (OS) or complications in patients with ovarian cancer.
Methods
Medline, Embase, CINAHL, and PEDro databases were searched from inception to 15 February 2019. Studies evaluating the prognostic effect of SMI and SMRA on ovarian cancer survival or surgical complications were included. Risk of bias and study quality were evaluated with the Quality in Prognosis Studies Instrument (QUIPS) according to the modified Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework.
Results
The search strategy yielded 4262 hits in all four databases combined. Ten and eight studies were included for qualitative and quantitative analysis, respectively. Meta‐analysis revealed a significant association between the SMI and OS 0.007; hazard ratio (HR): 1.11, 95% confidence interval (CI): 1.03–1.20. SMRA was also significantly associated with OS (P < 0.001; HR: 1.14, 95% CI: 1.08–1.20). Association between the SMI and surgical complications had borderline statistical significance (0.05; HR: 1.23, 95% CI: 1.00–1.52). The risk of bias assessed with QUIPS was high in all studies. The quality of the evidence was very low.
Conclusions
Whereas our meta‐analysis indicated that a low SMI and low SMRA are associated with survival in ovarian cancer patients, the low quality of the source data precludes drawing definitive conclusions.

Relationship between pulmonary function and physical performance among community‐living people: results from Look‐up 7+ study

04-12-2019 – Francesco Landi, Sara Salini, Maria Beatrice Zazzara, Anna Maria Martone, Sofia Fabrizi, Mariangela Bianchi, Matteo Tosato, Anna Picca, Riccardo Calvani, Emanuele Marzetti

Journal Article

Abstract
Background
While respiratory muscle strength is recognized to decline with aging process, the relationship between sarcopenia and pulmonary function remains to be studied. The present study was undertaken to provide a better insight into the comprehension of the relationship between pulmonary function and muscle function (strength and physical performance) using an unselected sample of subjects assessed during the Longevity Check‐up 7+ project.
Methods
Look‐up 7+ is an ongoing cross‐sectional survey started in June 2015 and conducted in unconventional settings (i.e. exhibitions, malls, and health promotion campaigns) across Italy. Candidate participants are eligible for enrolment if they are at least 18 years of age and provide written informed consent. Muscle strength was assessed by handgrip strength test, and physical performance was evaluated by chair stand test. Spirometer analysis was performed using the Air
Smart system, and the largest forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and peak expiratory flow (PEF) values were collected.
Results
The mean age of 925 subjects participating in the Longevity check‐7+ surveys and receiving the spirometer evaluation was 55.6 years (range from 18 to 98 years), and 501 (54%) were women. Overall, both in male and female participants, FVC, FEV1 and PEF positively correlated with handgrip strength and chair stand tests. The receiver operator characteristic curve analysis revealed that the areas under the curves for FVC, FEV1, and PEF were 0.79, 0.80 and 0.80, respectively.
Conclusions
The results clearly show that pulmonary function was positively associated with handgrip strength and chair stand tests. Based on this observation, muscle strength, physical performance, and pulmonary function should be recommended as the method of choice for the early detection of individuals at risk of probable sarcopenia and at the same time to better characterized the severity of sarcopenia status.

Muscle mass, strength, and physical performance predicting activities of daily living: a meta‐analysis

01-12-2019 – Daniel X.M. Wang, Jessica Yao, Yasar Zirek, Esmee M. Reijnierse, Andrea B. Maier

Journal Article, Review

Abstract
Background
Activities of daily living (ADLs) and instrumental activities of daily living (IADLs) are essential for independent living and are predictors of morbidity and mortality in older populations. Older adults who are dependent in ADLs and IADLs are also more likely to have poor muscle measures defined as low muscle mass, muscle strength, and physical performance, which further limit their ability to perform activities. The aim of this systematic review and meta‐analysis was to determine if muscle measures are predictive of ADL and IADL in older populations.
Methods
A systematic search was conducted using four databases (MEDLINE, EMBASE, Cochrane, and CINAHL) from date of inception to 7 June 2018. Longitudinal cohorts were included that reported baseline muscle measures defined by muscle mass, muscle strength, and physical performance in conjunction with prospective ADL or IADL in participants aged 65 years and older at follow‐up. Meta‐analyses were conducted using a random effect model.
Results
Of the 7760 articles screened, 83 articles were included for the systematic review and involved a total of 108 428 (54.8% female) participants with a follow‐up duration ranging from 11 days to 25 years. Low muscle mass was positively associated with ADL dependency in 5/9 articles and 5/5 for IADL dependency. Low muscle strength was associated with ADL dependency in 22/34 articles and IADL dependency in 8/9 articles. Low physical performance was associated with ADL dependency in 37/49 articles and with IADL dependency in 9/11 articles. Forty‐five articles were pooled into the meta‐analyses, 36 reported ADL, 11 reported IADL, and 2 reported ADL and IADL as a composite outcome. Low muscle mass was associated with worsening ADL (pooled odds ratio (95% confidence interval) 3.19 (1.29–7.92)) and worsening IADL (1.28 (1.02–1.61)). Low handgrip strength was associated with both worsening ADL and IADL (1.51 (1.34–1.70); 1.59 (1.04–2.31) respectively). Low scores on the short physical performance battery and gait speed were associated with worsening ADL (3.49 (2.47–4.92); 2.33 (1.58–3.44) respectively) and IADL (3.09 (1.06–8.98); 1.93 (1.69–2.21) respectively). Low one leg balance (2.74 (1.31–5.72)), timed up and go (3.41 (1.86–6.28)), and chair stand test time (1.90 (1.63–2.21)) were associated with worsening ADL.
Conclusions
Muscle measures at baseline are predictors of future ADL and IADL dependence in the older adult population.

Effects of aerobic and inspiratory training on skeletal muscle microRNA‐1 and downstream‐associated pathways in patients with heart failure

19-11-2019 – Ligia M. Antunes‐Correa, Patricia F. Trevizan, Aline V.N. Bacurau, Larissa Ferreira‐Santos, João L.P. Gomes, Ursula Urias, Patricia A. Oliveira, Maria Janieire N.N. Alves, Dirceu R. Almeida, Patricia C. Brum, Edilamar M. Oliveira, Ludhmila Hajjar, Roberto Kalil Filho, Carlos Eduardo Negrão

Journal Article

Abstract
Background
The exercise intolerance in chronic heart failure with reduced ejection fraction (HFr
EF) is mostly attributed to alterations in skeletal muscle. However, the mechanisms underlying the skeletal myopathy in patients with HFr
EF are not completely understood. We hypothesized that (i) aerobic exercise training (AET) and inspiratory muscle training (IMT) would change skeletal muscle micro
RNA‐1 expression and downstream‐associated pathways in patients with HFr
EF and (ii) AET and IMT would increase leg blood flow (LBF), functional capacity, and quality of life in these patients.
Methods
Patients age 35 to 70 years, left ventricular ejection fraction (LVEF) ≤40%, New York Heart Association functional classes II–III, were randomized into control, IMT, and AET groups. Skeletal muscle changes were examined by vastus lateralis biopsy. LBF was measured by venous occlusion plethysmography, functional capacity by cardiopulmonary exercise test, and quality of life by Minnesota Living with Heart Failure Questionnaire. All patients were evaluated at baseline and after 4 months.
Results
Thirty‐three patients finished the study protocol: control (n = 10; LVEF = 25 ± 1%; six males), IMT (n = 11; LVEF = 31 ± 2%; three males), and AET (n = 12; LVEF = 26 ± 2%; seven males). AET, but not IMT, increased the expression of micro
RNA‐1 (P = 0.02; percent changes = 53 ± 17%), decreased the expression of PTEN (P = 0.003; percent changes = −15 ± 0.03%), and tended to increase the p‐AKTser473/AKT ratio (P = 0.06). In addition, AET decreased HDAC4 expression (P = 0.03; percent changes = −40 ± 19%) and upregulated follistatin (P = 0.01; percent changes = 174 ± 58%), MEF2C (P = 0.05; percent changes = 34 ± 15%), and Myo
D expression (P = 0.05; percent changes = 47 ± 18%). AET also increased muscle cross‐sectional area (P = 0.01). AET and IMT increased LBF, functional capacity, and quality of life. Further analyses showed a significant correlation between percent changes in micro
RNA‐1 and percent changes in follistatin m
RNA (P = 0.001, rho = 0.58) and between percent changes in follistatin m
RNA and percent changes in peak VO2 (P = 0.004, rho = 0.51).
Conclusions
AET upregulates micro
RNA‐1 levels and decreases the protein expression of PTEN, which reduces the inhibitory action on the PI3K‐AKT pathway that regulates the skeletal muscle tropism. The increased levels of micro
RNA‐1 also decreased HDAC4 and increased MEF2c, Myo
D, and follistatin expression, improving skeletal muscle regeneration. These changes associated with the increase in muscle cross‐sectional area and LBF contribute to the attenuation in skeletal myopathy, and the improvement in functional capacity and quality of life in patients with HFr
EF. IMT caused no changes in micro
RNA‐1 and in the downstream‐associated pathway. The increased functional capacity provoked by IMT seems to be associated with amelioration in the respiratory function instead of changes in skeletal muscle.
Clinical
Trials.gov (Identifier: NCT01747395)

Derangements of amino acids in cachectic skeletal muscle are caused by mitochondrial dysfunction

13-11-2019 – Thomas Kunzke, Achim Buck, Verena M. Prade, Annette Feuchtinger, Olga Prokopchuk, Marc E. Martignoni, Simone Heisz, Hans Hauner, Klaus‐Peter Janssen, Axel Walch, Michaela Aichler

Journal Article

Abstract
Background
Cachexia is the direct cause of at least 20% of cancer‐associated deaths. Muscle wasting in skeletal muscle results in weakness, immobility, and death secondary to impaired respiratory muscle function. Muscle proteins are massively degraded in cachexia; nevertheless, the molecular mechanisms related to this process are poorly understood. Previous studies have reported conflicting results regarding the amino acid abundances in cachectic skeletal muscle tissues. There is a clear need to identify the molecular processes of muscle metabolism in the context of cachexia, especially how different types of molecules are involved in the muscle wasting process.
Methods
New in situ ‐omics techniques were used to produce a more comprehensive picture of amino acid metabolism in cachectic muscles by determining the quantities of amino acids, proteins, and cellular metabolites. Using matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry imaging, we determined the in situ concentrations of amino acids and proteins, as well as energy and other cellular metabolites, in skeletal muscle tissues from genetic mouse cancer models (n = 21) and from patients with cancer (n = 6). Combined results from three individual MALDI mass spectrometry imaging methods were obtained and interpreted. Immunohistochemistry staining for mitochondrial proteins and myosin heavy chain expression, digital image analysis, and transmission electron microscopy complemented the MALDI mass spectrometry imaging results.
Results
Metabolic derangements in cachectic mouse muscle tissues were detected, with significantly increased quantities of lysine, arginine, proline, and tyrosine (P = 0.0037, P = 0.0048, P = 0.0430, and P = 0.0357, respectively) and significantly reduced quantities of glutamate and aspartate (P = 0.0008 and P = 0.0124). Human skeletal muscle tissues revealed similar tendencies. A majority of altered amino acids were released by the breakdown of proteins involved in oxidative phosphorylation. Decreased energy charge was observed in cachectic muscle tissues (P = 0.0101), which was related to the breakdown of specific proteins. Additionally, expression of the cationic amino acid transporter CAT1 was significantly decreased in the mitochondria of cachectic mouse muscles (P = 0.0133); this decrease may play an important role in the alterations of cationic amino acid metabolism and decreased quantity of glutamate observed in cachexia.
Conclusions
Our results suggest that mitochondrial dysfunction has a substantial influence on amino acid metabolism in cachectic skeletal muscles, which appears to be triggered by diminished CAT1 expression, as well as the degradation of mitochondrial proteins. These findings provide new insights into the pathobiochemistry of muscle wasting.

Vitamin D repletion ameliorates adipose tissue browning and muscle wasting in infantile nephropathic cystinosis‐associated cachexia

13-11-2019 – Wai W. Cheung, Sheng Hao, Zhen Wang, Wei Ding, Ronghao Zheng, Alex Gonzalez, Jian‐Ying Zhan, Ping Zhou, Shiping Li, Mary C. Esparza, Hal M. Hoffman, Richard L. Lieber, Robert H. Mak

Journal Article

Abstract
Background
Ctns−/− mice, a mouse model of infantile nephropathic cystinosis, exhibit hypermetabolism with adipose tissue browning and profound muscle wasting. Ctns−/− mice are 25(OH)D3 and 1,25(OH)2D3 insufficient. We investigated whether vitamin D repletion could ameliorate adipose tissue browning and muscle wasting in Ctns−/− mice.
Methods
Twelve‐month‐old Ctns−/− mice and wild‐type controls were treated with 25(OH)D3 and 1,25(OH)2D3 (75 μg/kg/day and 60 ng/kg/day, respectively) or an ethylene glycol vehicle for 6 weeks. Serum chemistry and parameters of energy homeostasis were measured. We quantitated total fat mass and studied expression of molecules regulating adipose tissue browning, energy metabolism, and inflammation. We measured lean mass content, skeletal muscle fibre size, in vivo muscle function (grip strength and rotarod activity), and expression of molecules regulating muscle metabolism. We also analysed the transcriptome of skeletal muscle in Ctns−/− mice using RNAseq.
Results
Supplementation of 25(OH)D3 and 1,25(OH)2D3 normalized serum concentration of 25(OH)D3 and 1,25(OH)2D3 in Ctns−/− mice, respectively. Repletion of vitamin D partially or fully normalized food intake, weight gain, gain of fat, and lean mass, improved energy homeostasis, and attenuated perturbations of uncoupling proteins and adenosine triphosphate content in adipose tissue and muscle in Ctns−/− mice. Vitamin D repletion attenuated elevated expression of beige adipose cell biomarkers (UCP‐1, CD137, Tmem26, and Tbx1) as well as aberrant expression of molecules implicated in adipose tissue browning (Cox2, Pgf2α, and NF‐κB pathway) in inguinal white adipose tissue in Ctns−/− mice. Vitamin D repletion normalized skeletal muscle fibre size and improved in vivo muscle function in Ctns−/− mice. This was accompanied by correcting the increased muscle catabolic signalling (increased protein contents of IL‐1β, IL‐6, and TNF‐α as well as an increased gene expression of Murf‐2, atrogin‐1, and myostatin) and promoting the decreased muscle regeneration and myogenesis process (decreased gene expression of Igf1, Pax7, and Myo
D) in skeletal muscles of Ctns−/− mice. Muscle RNAseq analysis revealed aberrant gene expression profiles associated with reduced muscle and neuron regeneration, increased energy metabolism, and fibrosis in Ctns−/− mice. Importantly, repletion of 25(OH)D3 and 1,25(OH)2D3 normalized the top 20 differentially expressed genes in Ctns−/− mice.
Conclusions
We report the novel findings that correction of 25(OH)D3 and 1,25(OH)2D3 insufficiency reverses cachexia and may improve quality of life by restoring muscle function in an animal model of infantile nephropathic cystinosis. Mechanistically, vitamin D repletion attenuates adipose tissue browning and muscle wasting in Ctns−/− mice via multiple cellular and molecular mechanisms.

mTORC1 signalling is not essential for the maintenance of muscle mass and function in adult sedentary mice

07-11-2019 – Alexander S. Ham, Kathrin Chojnowska, Lionel A. Tintignac, Shuo Lin, Alexander Schmidt, Daniel J. Ham, Michael Sinnreich, Markus A. Rüegg

Journal Article

Abstract
Background
The balance between protein synthesis and degradation (proteostasis) is a determining factor for muscle size and function. Signalling via the mammalian target of rapamycin complex 1 (m
TORC1) regulates proteostasis in skeletal muscle by affecting protein synthesis and autophagosomal protein degradation. Indeed, genetic inactivation of m
TORC1 in developing and growing muscle causes atrophy resulting in a lethal myopathy. However, systemic dampening of m
TORC1 signalling by its allosteric inhibitor rapamycin is beneficial at the organismal level and increases lifespan. Whether the beneficial effect of rapamycin comes at the expense of muscle mass and function is yet to be established.
Methods
We conditionally ablated the gene coding for the m
TORC1‐essential component raptor in muscle fibres of adult mice inducible raptor muscle‐specific knockout (i
RAm
KO). We performed detailed phenotypic and biochemical analyses of i
RAm
KO mice and compared them with muscle‐specific raptor knockout (RAm
KO) mice, which lack raptor in developing muscle fibres. We also used polysome profiling and proteomics to assess protein translation and associated signalling in skeletal muscle of i
RAm
KO mice.
Results
Analysis at different time points reveal that, as in RAm
KO mice, the proportion of oxidative fibres decreases, but slow‐type fibres increase in i
RAm
KO mice. Nevertheless, no significant decrease in body and muscle mass or muscle fibre area was detected up to 5 months post‐raptor depletion. Similarly, ex vivo muscle force was not significantly reduced in i
RAm
KO mice. Despite stable muscle size and function, inducible raptor depletion significantly reduced the expression of key components of the translation machinery and overall translation rates.
Conclusions
Raptor depletion and hence complete inhibition of m
TORC1 signalling in fully grown muscle leads to metabolic and morphological changes without inducing muscle atrophy even after 5 months. Together, our data indicate that maintenance of muscle size does not require m
TORC1 signalling, suggesting that rapamycin treatment is unlikely to negatively affect muscle mass and function.

The authors reply: Letter on: “Fibroblast growth factor 21 controls mitophagy and muscle mass” by Oost et al.

06-11-2019 – Lynette J. Oost, Marco Sandri, Vanina Romanello

Letter

The relationship between the BMI‐adjusted weight loss grading system and quality of life in patients with incurable cancer

06-11-2019 – Louise Daly, Ross Dolan, Derek Power, Éadaoin Ní Bhuachalla, Wei Sim, Marie Fallon, Samantha Cushen, Claribel Simmons, Donald C. McMillan, Barry J. Laird, Aoife Ryan

Journal Article

Abstract
Background
Weight loss (WL) has long been recognized as an important factor associated with reduced quality of life (QoL) and reduced survival in patients with cancer. The body mass index (BMI)‐adjusted weight loss grading system (WLGS) has been shown to be associated with reduced survival. However, its impact on QoL has not been established. The aim of this study was to assess the relationship between this WLGS and QoL in patients with advanced cancer.
Methods
A biobank analysis was undertaken of adult patients with advanced cancer. Data collected included patient demographics, Eastern Cooperative Oncology Group performance status, and anthropometric parameters (BMI and %WL). Patients were categorized according to the BMI‐adjusted WLGS into one of five distinct WL grades (grades 0–4). QoL was collected using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire‐C30. The Kruskal–Wallis test and multivariate logistic regression analyses were used to assess the relationship between the WLGS and QoL scores. Overall survival was assessed using Kaplan–Meier curve and Cox proportional hazard models.
Results
A total of 1027 patients were assessed (51% male, median age: 66 years). Gastrointestinal cancer was most prevalent (40%), and 87% of patients had metastatic disease. Half (58%) of patients had a WL grade of 0–1, while 12%, 20%, and 10% had WL grades of 2, 3, and 4, respectively. Increasing WL grades were significantly associated with poorer QoL functioning and symptoms scales (all P < 0.05). Physical, role, and emotional functioning decreased by a median of >20 points between WL grade 0 and WL grade 4, while appetite loss, pain, dyspnoea, and fatigue increased by a median score >20 points, indicative of a large clinical significant difference. Increasing WL grades were associated with deteriorating QoL summary score. WL grades 2, 3, and 4 were independently associated with a QoL summary score below the median (<77.7) odds ratio (OR) 1.69, P = 0.034; OR 2.06, P = 0.001; OR 4.29, P < 0.001, respectively. WL grades 3 and 4 were independently associated with reduced overall survival hazard ratio 1.54 (95% confidence interval: 1.22–1.93), P < 0.001 and hazard ratio 1.87 (95% confidence interval: 1.42–2.45), P < 0.001, respectively.
Conclusions
Our findings support that the WLGS is useful in identifying patients at risk of poor QoL that deteriorates with increasing WL grades. WL grade 4 is independently associated with a particularly worse prognosis and increased symptom burden. Identification and early referral to palliative care services may benefit these patients.

Skeletal muscle mTORC1 regulates neuromuscular junction stability

25-10-2019 – Martina Baraldo, Alessia Geremia, Marco Pirazzini, Leonardo Nogara, Francesca Solagna, Clara Türk, Hendrik Nolte, Vanina Romanello, Aram Megighian, Simona Boncompagni, Marcus Kruger, Marco Sandri, Bert Blaauw

Journal Article

Abstract
Background
Skeletal muscle is a plastic tissue that can adapt to different stimuli. It is well established that Mammalian Target of Rapamycin Complex 1 (m
TORC1) signalling is a key modulator in mediating increases in skeletal muscle mass and function. However, the role of m
TORC1 signalling in adult skeletal muscle homeostasis is still not well defined.
Methods
Inducible, muscle‐specific Raptor and m
TOR k.o. mice were generated. Muscles at 1 and 7 months after deletion were analysed to assess muscle histology and muscle force.
Results
We found no change in muscle size or contractile properties 1 month after deletion. Prolonging deletion of Raptor to 7 months, however, leads to a very marked phenotype characterized by weakness, muscle regeneration, mitochondrial dysfunction, and autophagy impairment. Unexpectedly, reduced m
TOR signalling in muscle fibres is accompanied by the appearance of markers of fibre denervation, like the increased expression of the neural cell adhesion molecule (NCAM). Both muscle‐specific deletion of m
TOR or Raptor, or the use of rapamycin, was sufficient to induce 3–8% of NCAM‐positive fibres (P < 0.01), muscle fibrillation, and neuromuscular junction (NMJ) fragmentation in 24% of examined fibres (P < 0.001). Mechanistically, reactivation of autophagy with the small peptide Tat‐beclin1 is sufficient to prevent mitochondrial dysfunction and the appearance of NCAM‐positive fibres in Raptor k.o. muscles.
Conclusions
Our study shows that m
TOR signalling in skeletal muscle fibres is critical for maintaining proper fibre innervation, preserving the NMJ structure in both the muscle fibre and the motor neuron. In addition, considering the beneficial effects of exercise in most pathologies affecting the NMJ, our findings suggest that part of these beneficial effects of exercise are through the well‐established activation of m
TORC1 in skeletal muscle during and after exercise.

Myopalladin promotes muscle growth through modulation of the serum response factor pathway

24-10-2019 – Maria Carmela Filomena, Daniel L. Yamamoto, Marco Caremani, Vinay K. Kadarla, Giuseppina Mastrototaro, Simone Serio, Anupama Vydyanath, Margherita Mutarelli, Arcamaria Garofalo, Irene Pertici, Ralph Knöll, Vincenzo Nigro, Pradeep K. Luther, Richard L. Lieber, Moriah R. Beck, Marco Linari, Marie‐Louise Bang

Journal Article

Abstract
Background
Myopalladin (MYPN) is a striated muscle‐specific, immunoglobulin‐containing protein located in the Z‐line and I‐band of the sarcomere as well as the nucleus. Heterozygous MYPN gene mutations are associated with hypertrophic, dilated, and restrictive cardiomyopathy, and homozygous loss‐of‐function truncating mutations have recently been identified in patients with cap myopathy, nemaline myopathy, and congenital myopathy with hanging big toe.
Methods
Constitutive MYPN knockout (MKO) mice were generated, and the role of MYPN in skeletal muscle was studied through molecular, cellular, biochemical, structural, biomechanical, and physiological studies in vivo and in vitro.
Results
MKO mice were 13% smaller compared with wild‐type controls and exhibited a 48% reduction in myofibre cross‐sectional area (CSA) and significantly increased fibre number. Similarly, reduced myotube width was observed in MKO primary myoblast cultures. Biomechanical studies showed reduced isometric force and power output in MKO mice as a result of the reduced CSA, whereas the force developed by each myosin molecular motor was unaffected. While the performance by treadmill running was similar in MKO and wild‐type mice, MKO mice showed progressively decreased exercise capability, Z‐line damage, and signs of muscle regeneration following consecutive days of downhill running. Additionally, MKO muscle exhibited progressive Z‐line widening starting from 8 months of age. RNA‐sequencing analysis revealed down‐regulation of serum response factor (SRF)‐target genes in muscles from postnatal MKO mice, important for muscle growth and differentiation. The SRF pathway is regulated by actin dynamics as binding of globular actin to the SRF‐cofactor myocardin‐related transcription factor A (MRTF‐A) prevents its translocation to the nucleus where it binds and activates SRF. MYPN was found to bind and bundle filamentous actin as well as interact with MRTF‐A. In particular, while MYPN reduced actin polymerization, it strongly inhibited actin depolymerization and consequently increased MRTF‐A‐mediated activation of SRF signalling in myogenic cells. Reduced myotube width in MKO primary myoblast cultures was rescued by transduction with constitutive active SRF, demonstrating that MYPN promotes skeletal muscle growth through activation of the SRF pathway.
Conclusions
Myopalladin plays a critical role in the control of skeletal muscle growth through its effect on actin dynamics and consequently the SRF pathway. In addition, MYPN is important for the maintenance of Z‐line integrity during exercise and aging. These results suggest that muscle weakness in patients with biallelic MYPN mutations may be associated with reduced myofibre CSA and SRF signalling and that the disease phenotype may be aggravated by exercise.

Association of change in muscle mass assessed by D3‐creatine dilution with changes in grip strength and walking speed

17-10-2019 – Kate A. Duchowny, Katherine E. Peters, Steven R. Cummings, Eric S. Orwoll, Andrew R. Hoffman, Kristine E. Ensrud, Jane A. Cauley, William J. Evans, Peggy M. Cawthon, for the Osteoporotic Fractures in Men (MrOS) Study Research Group

Journal Article

Abstract
Background
Muscle mass declines with age. However, common assessments used to quantify muscle mass are indirect. The D3‐creatine (D3Cr) dilution method is a direct assessment of muscle mass; however, longitudinal changes have not been examined in relation to changes in other measures of muscle mass, strength, and performance.
Methods
A convenience sample of 40 men from the Osteoporotic Fractures in Men Study (mean age = 83.3 years, standard deviation = 3.9) underwent repeat assessment of D3Cr muscle mass, dual‐energy X‐ray absorptiometry (DXA) lean mass, grip strength, and walking speed at two time points approximately 1.6 years apart (2014–2016). One‐sample t‐tests and Pearson correlations were used to examine changes in DXA total body lean mass, DXA appendicular lean mass/height2, DXA appendicular lean mass/weight, D3Cr muscle mass, D3Cr muscle mass/weight, grip strength, walking speed, and weight.
Results
D3‐creatine muscle mass, D3Cr muscle mass/weight, grip strength, and walking speed all significantly declined (all P < 0.01). The change in DXA measures of lean mass was moderately correlated with changes in D3Cr muscle mass. There was no significant correlation between the change in DXA measures of lean mass and change in walking speed (all P > 0.05). The change in D3Cr muscle mass/weight was moderately correlated with change in walking speed (r = 0.33, P < .05). The change in grip strength was weakly correlated with the change in DXA measures of lean mass and D3Cr muscle mass (r = 0.19–0.32).
Conclusions
The results of our study provide new insights regarding the decline in muscle strength and D3Cr muscle mass. The D3Cr method may be a feasible tool to measure declines in muscle mass over time.

Disease‐induced and treatment‐induced alterations in body composition in locally advanced head and neck squamous cell carcinoma

19-09-2019 – Anna C.H. Willemsen, Ann Hoeben, Roy I. Lalisang, Ardy Van Helvoort, Frederik W.R. Wesseling, Frank Hoebers, Laura W.J. Baijens, Annemie M.W.J. Schols

Journal Article

Abstract
Background
Chemoradiation or bioradiation treatment (CRT/BRT) of locally advanced head and neck squamous cell carcinoma (LAHNSCC) comes with high toxicity rates, often leading to temporary tube feeding (TF) dependency. Cachexia is a common problem in LAHNSCC. Yet changes in body composition and muscle weakness during CRT/BRT are underexplored. Strong evidence on the effect of TF on body composition during treatment is lacking. The aim of this cohort study was to assess (i) the relationship of fat‐free mass index (FFMI) and handgrip strength (HGS) with CRT/BRT toxicity and outcome, (ii) body composition in patients treated with chemoradiation (cisplatin) vs. bioradiation (cetuximab), and (iii) the effect of the current TF regime on body composition and muscle strength.
Methods
Locally advanced head and neck squamous cell carcinoma patients treated with CRT/BRT between January 2013 and December 2016 were included (n = 137). Baseline measurements of body composition (bioelectrical impedance analysis) and HGS were performed. Toxicity grades (Common Terminology Criteria for Adverse Events) were scored. In a subset of 69 patients, weight loss, body composition, and HGS were additionally assessed during and after CRT/BRT. TF was initiated according to the Dutch guidelines for malnutrition.
Results
In this cohort (68% male, mean age 59 ± 8 years), the incidence of baseline muscle wasting, defined as FFMI < P10, was 29%. Muscle wasting was present in 23 of 100 (23%) chemoradiation patients and 17 of 37 (46%) bioradiation patients (P = 0.009). Muscle‐wasted patients required more unplanned hospitalizations during CRT (P = 0.035). In the chemoradiation subset, dose‐limiting toxicity was significantly higher in wasted vs. non‐wasted patients (57% vs. 25%, P = 0.004). Median follow‐up was 32 months. Multivariate Cox regression analysis identified muscle wasting as independent unfavourable prognostic factor for overall survival hazard ratio 2.1 (95% CI 1.1–4.1), P = 0.022 and cisplatin as favourable prognostic factor hazard ratio 0.3 (95% CI 0.2–0.6), P = 0.001. Weight and HGS significantly decreased during CRT/BRT, −3.7 ± 3.5 kg (P < 0.001) and −3.1 ± 6.0 kg (P < 0.001), respectively. Sixty‐four per cent of the patients required TF 21 days (range 0–59) after CRT/BRT initiation. Total weight loss during CRT/BRT was significantly (P = 0.007) higher in the total oral diet group (5.5 ± 3.7 kg) compared with the TF group (3.0 ± 3.2 kg). Loss of FFM and HGS was similar in both groups.
Conclusions
In LAHNSCC patients undergoing CRT/BRT, FFMI < P10 is an unfavourable prognostic factor for overall survival, treatment toxicity, and tolerance. Patients experience significant weight and FFM loss during treatment. Current TF regime attenuates weight loss but does not overcome loss of muscle mass and function during therapy. Future interventions should consider nutritional intake and additional strategies specifically targeting metabolism, loss of muscle mass, and function.

Prognostic role of body composition parameters in gastric/gastroesophageal junction cancer patients from the EXPAND trial

28-08-2019 – Ulrich T. Hacker, Dirk Hasenclever, Nicolas Linder, Gertraud Stocker, Hyun‐Cheol Chung, Yoon‐Koo Kang, Markus Moehler, Harald Busse, Florian Lordick

Journal Article

Abstract
Background
Body fat and/or muscle composition influences prognosis in several cancer types. For advanced gastric and gastroesophageal junction cancer, we investigated which body composition parameters carry prognostic information beyond well‐established clinical parameters using robust model selection strategy such that parameters identified can be expected to generalize and to be reproducible beyond our particular data set. Then we modelled how differences in these parameters translate into survival outcomes.
Methods
Fat and muscle parameters were measured on baseline computed tomography scans in 761 patients with advanced gastric or gastroesophageal junction cancer from the phase III EXPAND trial, undergoing first‐line chemotherapy. Cox regression analysis for overall survival (OS) and progression‐free survival (PFS) included body composition parameters and clinical prognostic factors. All continuous variables were entered linearly into the model as there was no evidence of non‐linear prognostic impact. For transferability, the final model included only parameters that were picked by Bayesian information criterion model selection followed by bootstrap analysis to identify the most robust model.
Results
Muscle and fat parameters formed correlation clusters without relevant between‐cluster correlation. Mean muscle attenuation (MA) clusters with the fat parameters. In multivariate analysis, MA was prognostic for OS (P < 0.0001) but not for PFS, while skeletal muscle index was prognostic for PFS (P = 0.02) but not for OS. Worse performance status Eastern Cooperative Oncology Group (ECOG 1/0), younger age (on a linear scale), and the number of metastatic sites were strong negative clinical prognostic factors for both OS and PFS. MA remained in the model for OS (P = 0.0001) following Bayesian information criterion model selection in contrast to skeletal muscle index that remained prognostic for PFS (P = 0.009). Applying stricter criteria for transferability, MA represented the only prognostic body composition parameter for OS, selected in >80% of bootstrap replicates. Finally, Cox model‐derived survival curves indicated that large differences in MA translate into only moderate differences in expected OS in this cohort.
Conclusions
Among body composition parameters, only MA has robust prognostic impact for OS. Data suggest that treatment approaches targeting muscle quality are unlikely to prolong OS noticeably on their own in advanced gastric cancer patients, indicating that multimodal approaches should be pursued in the future.

Serum amyloid A1 mediates myotube atrophy via Toll‐like receptors

23-08-2019 – Alexander Hahn, Melanie Kny, Cristina Pablo‐Tortola, Mihail Todiras, Michael Willenbrock, Sibylle Schmidt, Katrin Schmoeckel, Ilka Jorde, Marcel Nowak, Ernst Jarosch, Thomas Sommer, Barbara M. Bröker, Stephan B. Felix, Claus Scheidereit, Steffen Weber‐Carstens, Christian Butter, Friedrich C. Luft, Jens Fielitz

Journal Article

Abstract
Background
Critically ill patients frequently develop muscle atrophy and weakness in the intensive‐care‐unit setting intensive care unit‐acquired weakness (ICUAW). Sepsis, systemic inflammation, and acute‐phase response are major risk factors. We reported earlier that the acute‐phase protein serum amyloid A1 (SAA1) is increased and accumulates in muscle of ICUAW patients, but its relevance was unknown. Our objectives were to identify SAA1 receptors and their downstream signalling pathways in myocytes and skeletal muscle and to investigate the role of SAA1 in inflammation‐induced muscle atrophy.
Methods
We performed cell‐based in vitro and animal in vivo experiments. The atrophic effect of SAA1 on differentiated C2C12 myotubes was investigated by analysing gene expression, protein content, and the atrophy phenotype. We used the cecal ligation and puncture model to induce polymicrobial sepsis in wild type mice, which were treated with the IкB kinase inhibitor Bristol‐Myers Squibb (BMS)‐345541 or vehicle. Morphological and molecular analyses were used to investigate the phenotype of inflammation‐induced muscle atrophy and the effects of BMS‐345541 treatment.
Results
The SAA1 receptors Tlr2, Tlr4, Cd36, P2rx7, Vimp, and Scarb1 were all expressed in myocytes and skeletal muscle. Treatment of differentiated C2C12 myotubes with recombinant SAA1 caused myotube atrophy and increased interleukin 6 (Il6) gene expression. These effects were mediated by Toll‐like receptors (TLR) 2 and 4. SAA1 increased the phosphorylation and activity of the transcription factor nuclear factor ‘kappa‐light‐chain‐enhancer’ of activated B‐cells (NF‐κB) p65 via TLR2 and TLR4 leading to an increased binding of NF‐κB to NF‐κB response elements in the promoter region of its target genes resulting in an increased expression of NF‐κB target genes. In polymicrobial sepsis, skeletal muscle mass, tissue morphology, gene expression, and protein content were associated with the atrophy response. Inhibition of NF‐κB signalling by BMS‐345541 increased survival (28.6% vs. 91.7%, P < 0.01). BMS‐345541 diminished inflammation‐induced atrophy as shown by a reduced weight loss of the gastrocnemius/plantaris (vehicle: −21.2% and BMS‐345541: −10.4%; P < 0.05), tibialis anterior (vehicle: −22.7% and BMS‐345541: −17.1%; P < 0.05) and soleus (vehicle: −21.1% and BMS‐345541: −11.3%; P < 0.05) in septic mice. Analysis of the fiber type specific myocyte cross‐sectional area showed that BMS‐345541 reduced inflammation‐induced atrophy of slow/type I and fast/type II myofibers compared with vehicle‐treated septic mice. BMS‐345541 reversed the inflammation‐induced atrophy program as indicated by a reduced expression of the atrogenes Trim63/Mu
RF1, Fbxo32/Atrogin1, and Fbxo30/Mu
SA1.
Conclusions
SAA1 activates the TLR2/TLR4//NF‐κB p65 signalling pathway to cause myocyte atrophy. Systemic inhibition of the NF‐κB pathway reduced muscle atrophy and increased survival of septic mice. The SAA1/TLR2/TLR4//NF‐κB p65 atrophy pathway could have utility in combatting ICUAW.

Predictivity of bioimpedance phase angle for incident disability in older adults

22-08-2019 – Kazuki Uemura, Takehiko Doi, Kota Tsutsumimoto, Sho Nakakubo, Min‐Ji Kim, Satoshi Kurita, Hideaki Ishii, Hiroyuki Shimada

Journal Article

Abstract
Background
Bioelectrical impedance analysis (BIA)‐derived phase angle is expected to be an efficient prognostic marker of health adverse events with aging as an alternative of muscle mass. We aimed to examine the predictive ability of phase angle for incident disability in community‐dwelling elderly and determine the optimal cut‐off values.
Methods
Community‐dwelling elderly aged ≥65 years (n = 4452; mean age = 71.8 ± 5.3 years, 48.3% women) without disability at baseline participated in this prospective cohort study. Phase angle and appendicular skeletal muscle mass (ASM) were examined using a multi‐frequency BIA at baseline. Other potential confounding factors (demographics, cognitive function, depressive symptoms, medications, and physical performance) were also assessed. Incident disability was monitored on the basis of long‐term care insurance certification.
Results
Over a follow‐up of 24 months, 4.0% (n = 174) experienced disability, with an overall incidence rate of 20.6 per 1000 person‐years. The Cox hazard regression analysis showed that phase angle, as a continuous variable, was independently associated with incident disability after adjusting the covariates male: hazard ratios (HRs) = 0.61, 95% confidence interval (CI) = 0.37–0.98; female: HR = 0.58, 95% CI = 0.37–0.90, although body mass index adjusted ASM was not. Receiver operating characteristic analysis indicated moderate predictive abilities of phase angle for incident disability male: area under the receiver operating characteristic curve (AUC) = 0.76, 95% CI = 0.70–0.83; female: AUC = 0.71, 95% CI = 0.65–0.76, while those of body mass index adjusted ASM were low (male: AUC = 0.59, 95% CI = 0.521–0.66; female: AUC = 0.58, 95% CI = 0.52–0.63). Multivariate Cox regression analysis showed that low phase angle categorized by cut‐off value (male, ≤4.95°; female, ≤4.35°) was independently related to increased risk of incident disability (HR = 1.95, 95% CI = 1.37–2.78).
Conclusions
Lower phase angle independently predicts the incident disability separately from known risk factors. BIA‐derived phase angle can be used as a valuable and simple prognostic tool to identify the elderly at risk of disability as targets of preventive treatment.

Autocrine activin A signalling in ovarian cancer cells regulates secretion of interleukin 6, autophagy, and cachexia

21-08-2019 – Kristine Pettersen, Sonja Andersen, Anna Veen, Unni Nonstad, Shinji Hatakeyama, Christian Lambert, Estelle Lach‐Trifilieff, Siver Moestue, Jana Kim, Bjørn Henning Grønberg, Alain Schilb, Carsten Jacobi, Geir Bjørkøy

Journal Article

Abstract
Background
The majority of patients with advanced cancer develop cachexia, a weight loss syndrome that severely reduces quality of life and limits survival. Our understanding of the underlying mechanisms that cause the condition is limited, and there are currently no treatment options that can completely reverse cachexia. Several tumour‐derived factors and inflammatory mediators have been suggested to contribute to weight loss in cachectic patients. However, inconsistencies between studies are recurrent. Activin A and interleukin 6 (IL‐6) are among the best studied factors that seem to be important, and several studies support their individual role in cachexia development.
Methods
We investigated the interplay between activin A and IL‐6 in the cachexia‐inducing TOV21G cell line, both in culture and in tumours in mice. We previously found that the human TOV21G cells secrete IL‐6 that induces autophagy in reporter cells and cachexia in mice. Using this established cachexia cell model, we targeted autocrine activin A by genetic, chemical, and biological approaches. The secretion of IL‐6 from the cancer cells was determined in both culture and tumour‐bearing mice by a species‐specific ELISA. Autophagy reporter cells were used to monitor the culture medium for autophagy‐inducing activities, and muscle mass changes were evaluated in tumour‐bearing mice.
Results
We show that activin A acts in an autocrine manner to promote the synthesis and secretion of IL‐6 from cancer cells. By inhibiting activin A signalling, the production of IL‐6 from the cancer cells is reduced by 40–50% (up to 42% reduction on protein level, P = 0.0048, and 48% reduction on m
RNA level, P = 0.0308). Significantly reduced IL‐6 secretion (P < 0.05) from the cancer cells is consistently observed when using biological, chemical, and genetic approaches to interfere with the autocrine activin A loop. Inhibiting activin signalling also reduces the ability of the cancer cells to accelerate autophagy in non‐cancerous cells (up to 43% reduced autophagy flux, P = 0.0006). Coherent to the in vitro data, the use of an anti‐activin receptor 2 antibody in cachectic tumour‐bearing mice reduces serum levels of cancer cell‐derived IL‐6 by 62% (from 417 to 159 pg/m
L, P = 0.03), and, importantly, it reverses cachexia and counteracts loss of all measured muscle groups (P < 0.0005).
Conclusions
Our data support a functional link between activin A and IL‐6 signalling pathways and indicate that interference with activin A‐induced IL‐6 secretion from the tumour has therapeutic potential for cancer‐induced cachexia.

Defining barriers to implementation of nutritional advice in patients with cachexia

21-08-2019 – Rima Nasrah, Christina Van Der Borch, Mary Kanbalian, R. Thomas Jagoe

Journal Article

Abstract
Background
Cancer cachexia is a multidimensional wasting syndrome and a reduced dietary intake is both common and strongly correlated with degree of weight loss. Many patients with cachexia do not achieve recommended dietary intake even after nutritional counselling. Prior reports suggest this is likely due to barrier symptoms, but other potential contributory factors have not been studied in detail.
Methods
Dietitian‐assigned barriers to successful nutritional intervention were recorded at each visit in all patients attending a multidisciplinary clinic for management of cancer cachexia. The barriers were grouped into 15 categories and classified as either symptom‐related or not symptom‐related. In addition, symptom scores, dietary intake, and weight change were recorded.
Results
Data on 94 new patients showed that 89% of patients had at least one major barrier. Four of the five most common barriers and 65% of all barriers identified were not symptom‐related. Over sequential visits the specific barrier(s) in any one patient changed approximately 50% of the time. However, the presence of barriers did not render patients refractory to nutritional intervention and with intervention from the CNR‐JGH team, mean dietary intake increased significantly.
Conclusions
In advanced cancer patients with cachexia, non‐symptom‐related barriers to nutritional intervention are more common than symptom‐related. Barriers are dynamic, and repeated careful evaluation over time is required to achieve optimal impact with nutritional intervention in cancer cachexia. Members of the multidisciplinary team need appropriate expertise to address the barriers identified and achieve optimal results with nutritional intervention.

Divergent skeletal muscle mitochondrial phenotype between male and female patients with chronic heart failure

20-08-2019 – Jack O. Garnham, Lee D. Roberts, Talia Caspi, Moza M. Al‐Owais, Max Bullock, Peter P. Swoboda, Aaron Koshy, John Gierula, Maria F. Paton, Richard M. Cubbon, Mark T. Kearney, T. Scott Bowen, Klaus K. Witte

Journal Article

Abstract
Background
Previous studies in heart failure with reduced ejection fraction (HFr
EF) suggest that skeletal muscle mitochondrial impairments are associated with exercise intolerance in men. However, the nature of this relationship in female patients remains to be elucidated. This study aimed to determine the relationship between skeletal muscle mitochondrial impairments and exercise intolerance in male and female patients with HFr
EF.
Methods
Mitochondrial respiration, enzyme activity, and gene expression were examined in pectoralis major biopsies from age‐matched male (n = 45) and female (n = 11) patients with HFr
EF and healthy‐matched male (n = 24) and female (n = 11) controls. Mitochondrial variables were compared between sex and related to peak exercise capacity.
Results
Compared with sex‐matched controls, complex I mitochondrial oxygen flux was 17% (P = 0.030) and 29% (P = 0.013) lower in male and female patients with HFr
EF, respectively, which correlated to exercise capacity (r = 0.71; P > 0.0001). Female HFr
EF patients had a 32% (P = 0.023) lower mitochondrial content compared with controls. However, after adjusting for mitochondrial content, male patients demonstrated lower complex I function by 15% (P = 0.030). Expression of key mitochondrial genes regulating organelle dynamics and maintenance (i.e. optic atrophy 1, peroxisome proliferator‐activated receptor γ coactivator‐1α, NADH:ubiquinone oxidoreductase core subunit S1/S3, and superoxide dismutase 2) were selectively lower in female HFr
EF patients.
Conclusions
These data provide novel evidence that HFr
EF induces divergent sex‐specific mitochondrial phenotypes in skeletal muscle that predispose towards exercise intolerance, impacting mitochondrial ‘quantity’ in female patients and mitochondrial ‘quality’ in male patients. Therapeutic strategies to improve exercise tolerance in HFr
EF should consider targeting sex‐specific mitochondrial abnormalities in skeletal muscle.

Comment on: “Fibroblast growth factor 21 controls mitophagy and muscle mass” by Oost et al.

15-07-2019 – Yeshun Wu, Bin Zhu, Zijun Chen, Jiahao Duan, Ling Yang

Letter