Prevalence, incidence, and clinical impact of sarcopenia: facts, numbers, and epidemiology-update 2014

Osteosarcopenic obesity in women: impact, prevalence, and management challenges

Osteosarcopenic obesity syndrome (OSO) has recently been identified as a condition encompassing osteopenia/osteoporosis, sarcopenia and obesity. OSO is especially deleterious in older adults (even if they are not obese by conventional measures), due to age-related redistribution of fat and its infiltration into bone and muscle. Osteoporosis and bone fractures in elderly increase the risk of sarcopenia, which, through decreased mobility, increases the risk of more falls and fractures, creating a vicious cycle. Obesity plays a dual role: to a certain extent, it promotes bone and muscle gains through mechanical loading; in contrast, increased adiposity is also a source of pro-inflammatory cytokines and other endocrine factors that impair bone and muscle. As the elderly population increases, changes in lifestyle to delay the onset of OSO, or prevent OSO, are warranted. Among these changes, dietary patterns and physical activity modifications are the first ones to be implemented. The typical Western diet (and lifestyle) promotes several chronic diseases including OSO, by facilitating a pro-inflammatory state, largely via the imbalance in omega-6/omega-3 fatty acid ratio and low-fiber and high-processed food consumption. Nutritional modifications to prevent and/or alleviate the OSO syndrome include adequate intake of protein, calcium, magnesium and vitamin D and increasing consumptions of foods containing omega-3 polyunsaturated fatty acids and fiber. Certain types of physical activity, often decreased in overweight/obese women and in elderly, might preserve bone and muscle, as well as help in reducing body fat accrual and fat infiltration. Habitual daily activities and some alternative modes of exercise may be more appropriate for older adults and play a crucial role in preventing bone and muscle loss and maintaining optimal weight. In conclusion, older adults who suffer from OSO syndrome may benefit from combined efforts to improve diet and physical activity, and such recommendations should be fostered as part of public health programs.

Physical Training and Activity in People With Diabetic Peripheral Neuropathy: Paradigm Shift

Diabetic peripheral neuropathy (DPN) occurs in more than 50% of people with diabetes and is an important risk factor for skin breakdown, amputation, and reduced physical mobility (ie, walking and stair climbing). Although many beneficial effects of exercise for people with diabetes have been well established, few studies have examined whether exercise provides comparable benefits to people with DPN. Until recently, DPN was considered to be a contraindication for walking or any weight-bearing exercise because of concerns about injuring a person's insensitive feet. These guidelines were recently adjusted, however, after research demonstrated that weight-bearing activities do not increase the risk of foot ulcers in people who have DPN but do not have severe foot deformity. Emerging research has revealed positive adaptations in response to overload stress in these people, including evidence for peripheral neuroplasticity in animal models and early clinical trials. This perspective article reviews the evidence for peripheral neuroplasticity in animal models and early clinical trials, as well as adaptations of the integumentary system and the musculoskeletal system in response to overload stress. These positive adaptations are proposed to promote improved function in people with DPN and to foster the paradigm shift to including weight-bearing exercise for people with DPN. This perspective article also provides specific assessment and treatment recommendations for this important, high-risk group.

Utility of SARC-F for Assessing Physical Function in Elderly Patients With Cardiovascular Disease

OBJECTIVES

A simple and inexpensive tool for screening of sarcopenia would be helpful for clinicians. The present study was performed to determine whether the SARC-F questionnaire is useful in screening of patients with cardiovascular disease (CVD) for impaired physical function.

DESIGN

Cross-sectional study.

SETTING

Single university hospital.

PARTICIPANTS

A total of 235 Japanese patients ≥65 years old admitted to our hospital for CVD.

MEASUREMENTS

SARC-F, handgrip strength, leg strength, respiratory muscle strength, standing balance, usual gait speed, Short Physical Performance Battery (SPPB) score, and 6-minute walking distance were measured before discharge from hospital. The patients were divided into 2 groups according to SARC-F score: SARC-F < 4 (nonsarcopenia group) and SARC-F ≥ 4 (sarcopenia group).

RESULTS

The sarcopenia prevalence rate was 25.5% and increased with age (P trend < .001). The sarcopenia group (SARC-F score ≥ 4) had significantly lower handgrip strength, leg strength, and respiratory muscle strength, poorer standing balance, slower usual gait speed, lower SPPB score, and shorter 6-minute walking distance compared to the nonsarcopenia group (SARC-F score < 4). Patients in the sarcopenia group had consistently poorer physical function even after adjusting for covariates.

CONCLUSION

The SARC-F questionnaire is a useful screening tool for impaired physical function in elderly CVD patients. These findings support the use of the SARC-F for screening in hospital settings.

Type 2 diabetes mellitus is associated with increased risks of sarcopenia and pre-sarcopenia in Chinese elderly

Sarcopenia is a condition characterized by progressive and generalized loss of skeletal muscle mass and function. In this study, we used a cross-sectional study with 1090 community-dwelling Chinese citizens aged 60 years and older to evaluate the association of type 2 diabetes mellitus (T2DM) with the risk of sarcopenia and pre-sarcopenia. Sarcopenia was defined using the Asian Working Group for Sarcopenia (AWGS) criteria that include both muscle mass and muscle function/physical activity. Pre-sarcopenia was defined as having low skeletal muscle index but with normal muscle/physical activity. The prevalence of sarcopenia and pre-sarcopenia was significantly higher in T2DM patients than in healthy controls (14.8% vs. 11.2%, p = 0.035 for sarcopenia, and 14.4% vs. 8.4%, p = 0.002 for pre-sarcopenia). In multivariate logistic regression analyses adjusting by age, gender, anti-diabetic medication, energy intake, protein intake, physical activity, and visceral fat area, we found that Chinese elderly with T2DM exhibited significantly increased risks of sarcopenia (OR = 1.37, 95% CI = 1.02-2.03) and pre-sarcopenia (OR = 1.73, 95% CI = 1.10-2.83) compared to non-diabetic individuals. This is the first study to evaluate the association of T2DM with the risks of sarcopenia and pre-sarcopenia in China. Among a group of community-dwelling Chinese elderly, T2DM was significantly associated with increased risks of sarcopenia and pre-sarcopenia.

Prevalence and clinical impact of cachexia in chronic illness in Europe, USA, and Japan: facts and numbers update 2016

Cachexia is a serious clinical consequence of almost all chronic diseases when reaching advanced stages. Its prevalence ranges from 5-15% in end-stage chronic heart failure to 50-80% in advanced malignant cancer. Cachexia is also frequently occurring in patients with chronic kidney disease, chronic obstructive pulmonary disease (COPD) or neurological diseases, and rheumatoid arthritis. Mortality rates of patients with cachexia range from 15-25% per year in severe COPD through 20-40% per year in patients with chronic heart failure or chronic kidney disease to 20-80% in cancer cachexia. In the industrialized world (North America, Europe, and Japan) where epidemiological data are to some degree available, the overall prevalence of cachexia (due to any disease and not necessarily associated with hospital admission) is growing with the growth of the chronic illness prevalence, and it currently affects around 0.5-1.0% of the population, i.e. around 6-12 million people. From this, one can estimate that 1.5-2 million deaths are occurring in patients with cachexia per year. It is also a very significant health problem in other parts of the globe, but epidemiological data are scarce. The multifactorial nature of cachexia is now much better understood, and particularly, the role of inflammatory mediators and the imbalance of anabolism and catabolism are considered important therapeutic targets. Several approaches to develop cachexia and muscle wasting treatments have failed to be successful in phase III clinical trials, but new approaches are in development. Given the high prevalence and very high mortality associated with cachexia, advances are urgently needed for patients worldwide.

Cachexia research in Japan: facts and numbers on prevalence, incidence and clinical impact

Even though most clinical data on cachexia have been reported from Western countries, cachexia may be a growing problem in Asia as well, as the population in this area of the world is considerably larger. Considering the current definitions of obesity and sarcopenia in Japan, which are different from the ones in Western countries, the lack of a distinct cachexia definition in Japan is strinking. Only one epidemiological study has reported the prevalence of cachexia using weight loss as part of the definition in patients with stage III or IV non-small cell lung cancer. Although the reported prevalence of 45.6% is within the range of that in Western countries (28-57% in advanced cancer), we cannot compare the prevalence of cachexia in other types of cancer, heart failure, chronic obstructive pulmonary disease (COPD), and kidney disease (CKD) between Japan and Western countries. In patients with heart failure, one third of Japanese patients has a body mass index <20.3 kg/m² whereas the prevalence of underweight is 13.6% in reports from Western countries. These results may suggest that there are more cachectic heart failure patients in Japan, or that using the same definition like Western countries leads to gross overestimation of the prevalence of cachexia in Japan. The rate of underweight patients in COPD has been reported as 31-41% in COPD and seems to be high in comparison to the prevalence of cachexia in Western countries (27-35%). The reported lowest quartile value of BMI (19.6 kg/m²) in CKD may match with the prevalence of cachexia in Western countries (30-60%). The number of clinical trials targeting cachexia is very limited in Japan so far.

Welcome to the ICD-10 code for sarcopenia

The new ICD-10-CM (M62.84) code for sarcopenia represents a major step forward in recognizing sarcopenia as a disease. This should lead to an increase in availability of diagnostic tools and the enthusiasm for pharmacological companies to develop drugs for sarcopenia.

Publication trends in cachexia and sarcopenia in elderly heart failure patients

The loss of skeletal mass - sarcopenia and cachexia - is considered to be a major contributor to morbidity and mortality in chronic heart failure (CHF). Unfortunately, sarcopenia is generally considered to be a geriatric syndrome, but not necessarily seen as a comorbidity in CHF, even though it has a wide range of adverse health outcomes. While there were 15,574 publication with the title word "heart failure" in PubMed in the 5‑year period from 1 June 2011 to 31 May 2016, only 22 or 71 publications were found with the search combination "sarcopenia" or "cachexia" (title word) and "heart failure" (all fields), respectively. This shows very clearly that loss of muscle quality and function due to heart failure is still an underappreciated problem in the medical field.

Sarcopenia and post-hospital outcomes in older adults: A longitudinal study

INTRODUCTION

Sarcopenia poses a significant problem for older adults, yet very little is known about this medical condition in the hospital setting. The aims of this hospital-based study were to determine: (i) the prevalence of sarcopenia; (ii) factors associated with sarcopenia; and (iii) the association of sarcopenia with adverse clinical outcomes post-hospitalisation.

METHODS

This is a longitudinal analysis of consecutive patients aged ≥70 years admitted to a Geriatric Management and Evaluation Unit (GEMU) ward. Sarcopenia was classified using the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm, which included: handgrip strength, gait speed, and muscle mass using Bioelectrical Impedance Analysis (BIA). Outcomes were assessed at 12-months post-hospital discharge, and included both mortality and admission to a hospital Emergency Department (ED). Kaplan-Meier methods were used to estimate survival, with Cox proportion hazard models then applied. All regression analyses controlled for age, sex, and co-morbidity.

RESULTS

172 patients (72% female) with a mean (SD) age of 85.2 (6.4) years were included. Sarcopenia was present in 69 (40.1%) of patients. Patients with sarcopenia were twice as likely to die in the 12-months post-hospitalisation (HR, 95% CI=2.23, 1.15-4.34), but did not have an increased likelihood of ED admission.

CONCLUSIONS

Sarcopenia showed an independent association with 12-month post-hospital mortality in older adults. With the new recognition of sarcopenia as a medical condition with its own unique ICD-10-CM code, awareness and diagnosis of sarcopenia in clinical settings is paramount.

Cross-Cultural Adaptation and Validation of the Spanish-Language Version of the SARC-F to Assess Sarcopenia in Mexican Community-Dwelling Older Adults

OBJECTIVES

To cross-culturally adapt and validate the Spanish-language version of the SARC-F in Mexican community-dwelling older adults.

DESIGN

Cross-sectional analysis of a prospective cohort.

SETTING

The FraDySMex study, a 2-round evaluation of community-dwelling adults from 2 municipalities in Mexico City.

PARTICIPANTS

Participants were 487 men and women older than 60 years, living in the designated area in Mexico City.

MEASUREMENTS

Information from questionnaires regarding demographic characteristics, comorbidities, mental status, nutritional status, dependence in activities of daily living, frailty, and quality of life. Objective measurements of muscle mass, strength and function were as follows: skeletal muscle mass index (SMI) was taken using dual-energy x-ray, grip strength using a hand dynamometer, 6-meter gait speed using a GAIT Rite instrumented walkway, peak torque and power for knee extension using a isokinetic dynamometer, lower extremity functioning measured by the Short Physical Performance Battery (SPPB), and balance using evaluation on a foam surface, with closed eyes, in the Modified Clinical Test of Sensory Integration. The SARC-F scale translated to Spanish and the consensus panels' criteria from European, international, and Asian sarcopenia working groups were applied to evaluate sarcopenia.

RESULTS

The Spanish language version of the SARC-F scale showed reliability (Cronbach alfa = 0.641. All items in the scale correlated to the scale's total score, rho = 0.43 to 0.76), temporal consistency evaluated by test-retest (CCI = 0.80), criterion validity when compared to the consensus panels' criteria (high specificity and negative predictive values). The scale was also correlated to other measures related to sarcopenia (such as age, quality of life, self-rated health status, cognition, dependence in activities of daily living, nutritional status, depression, gait speed, grip strength, peak torque and power for knee extension, SPPB, balance, SMI, and frailty).

CONCLUSION

The SARC-F scale was successfully adapted to Spanish language and validated in community-dwelling Mexican older adults.

Measuring the musculoskeletal aging phenotype

The world is aging. The population aged over sixty years worldwide is predicted to rise from 841 million in 2013 to more than 2 billion by 2050. Musculoskeletal (MSK) disease is a significant burden on the aging population, contributing 7.5% of the disease burden in those aged over 60 years. MSK diseases have a pronounced effect on disability level and independence in old age, with a consequent significant public health burden and impact on quality of later life. As numbers of older individuals and their disease burden increase, it is important to examine MSK disease in older life in detail. The musculoskeletal aging phenotype comprises four often interwoven key elements - osteoporosis, osteoarthritis, sarcopenia and frailty - and this review will focus on these four themes. It is crucial that we are able to accurately measure each phenotype in order that we might identify those individuals at greatest risk of developing these conditions, and design trials of therapeutic agents that might impact their development. Accurate measurement of the musculoskeletal aging phenotype is necessary firstly to document the burden of each condition, and then to enable factors to be identified which may accelerate or retard their development or progression. In some areas of MSK disease, this work is more advanced (osteoporosis); in other areas (sarcopenia) the field is currently very rapidly evolving. We will explore the tools currently used to measure the musculoskeletal aging phenotype and how they compare, as well as highlight areas where more work is needed.

Soy-Dairy Protein Blend or Whey Protein Isolate Ingestion Induces Similar Postexercise Muscle Mechanistic Target of Rapamycin Complex 1 Signaling and Protein Synthesis Responses in Older Men

Background: Previous work demonstrated that a soy-dairy protein blend (PB) prolongs hyperaminoacidemia and muscle protein synthesis in young adults after resistance exercise.

Objective: We investigated the effect of PB in older adults. We hypothesized that PB would prolong hyperaminoacidemia, enhancing mechanistic target of rapamycin complex 1 (mTORC1) signaling and muscle protein anabolism compared with a whey protein isolate (WPI).

Methods: This double-blind, randomized controlled trial studied men 55–75 y of age. Subjects consumed 30 g protein from WPI or PB (25% soy, 25% whey, and 50% casein) 1 h after leg extension exercise (8 sets of 10 repetitions at 70% one-repetition maximum). Blood and muscle amino acid concentrations and basal and postexercise muscle protein turnover were measured by using stable isotopic methods. Muscle mTORC1 signaling was assessed by immunoblotting.

Results: Both groups increased amino acid concentrations (P < 0.05) and mTORC1 signaling after protein ingestion (P < 0.05). Postexercise fractional synthesis rate (FSR; P ≥ 0.05), fractional breakdown rate (FBR; P ≥ 0.05), and net balance (P = 0.08) did not differ between groups. WPI increased FSR by 67% (mean ± SEM: rest: 0.05% ± 0.01%; postexercise: 0.09% ± 0.01%; P < 0.05), decreased FBR by 46% (rest: 0.17% ± 0.01%; postexercise: 0.09% ± 0.03%; P < 0.05), and made net balance less negative (P < 0.05). PB ingestion did not increase FSR (rest: 0.07% ± 0.03%; postexercise: 0.09% ± 0.01%; P ≥ 0.05), tended to decrease FBR by 42% (rest: 0.25% ± 0.08%; postexercise: 0.15% ± 0.08%; P = 0.08), and made net balance less negative (P < 0.05). Within-group percentage of change differences were not different between groups for FSR, FBR, or net balance (P ≥ 0.05).

Conclusions: WPI and PB ingestion after exercise in older men induced similar responses in hyperaminoacidemia, mTORC1 signaling, muscle protein synthesis, and breakdown. These data add new evidence for the use of whey or soy-dairy PBs as targeted nutritional interventions to counteract sarcopenia. This trial was registered at clinicaltrials.gov as NCT01847261.

Plasma Biomarkers of Poor Muscle Quality in Older Men and Women from the Baltimore Longitudinal Study of Aging

Aging is characterized by progressive decline in muscle mass, strength, and quality all of which contribute to functional impairment, falls, mobility disability, and frailty. Circulating factors may provide clues on the mechanisms for decline in muscle quality with aging. Characterizing the metabolic profile associated with reduced muscle quality in older persons could have important translational implications for the early identification of subjects at high risk of developing sarcopenia and the identification of targets for new preventive strategies and treatments. In a pilot cross-sectional, case-control study nested in the Baltimore Longitudinal Study on Aging, we compared circulating metabolites between 79 participants with low muscle quality ratio and 79 controls with high muscle quality, matched by age, sex, and height. The concentrations of 180 metabolites were determined by LC MS/MS, using the Biocrates p180 system, a targeted metabolomics approach. Participants with low muscle quality had significantly higher levels of leucine, isoleucine, tryptophan, serotonin, and methionine, while those with high muscle quality had significantly lower levels of putrescine and the selected phophatidylcholine (PCs) and lysoPCs. The results of this study open a new road for future investigations aimed at identifying new metabolic pathways involved in the decline of muscle quality with aging.

Frailty and sarcopenia in elderly

Frailty is a pre-disability syndrome where an older person can be identified as being at risk when exposed to stressors associated with high risk for disability or needing to be hospitalized. Two major frailty definitions exist. The physical phenotype of frailty and the multiple deficit model. A simple frailty screening tool-FRAIL-has been validated. Treatment of frailty involves resistance exercise, optimization of nutrition, and treatment of fatigue (sleep apnea, depression), treatable causes of weight loss and adjustment of polypharmacy. Sarcopenia (decline in function with low muscle mass) is a major cause of frailty. A simple sarcopenia screening tool-SARC-F-has been validated. The multiple causes of sarcopenia are reviewed. Optimal treatment is resistance exercise, leucine-enriched essential amino acids and vitamin D replacement.

Prevalence of malnutrition and sarcopenia in a post-acute care geriatric unit: Applying the new ESPEN definition and EWGSOP criteria

BACKGROUNDS & AIMS

The European Society of Clinical Nutrition and Metabolism (ESPEN) consensus definition of malnutrition has been applied in hospitalized older diabetics and middle-aged patients, geriatric outpatients, and healthy elderly and young individuals. In a post-acute care setting, our aim was to assess malnutrition (ESPEN definition) and determine its relationship with sarcopenia in older in-patients deconditioned due to an acute process.

METHODS

Eighty-eight in-patients aged ≥70 years with body mass index (BMI) <30 kg/m² were included (84.1 years old; 62% women) and screened for malnutrition risk using biochemical markers and Mini-Nutritional Assessment-Short Form (MNA-SF). The ESPEN definition was applied: 1) BMI <18.5 kg/m² or 2) unintentional weight loss plus a) low BMI or b) low fat-free mass index (FFMI). European Working Group on Sarcopenia in Older People (EWGSOP) criteria were also applied.

RESULTS

Unintentional weight loss occurred in 27 (30.7%) of 88 in-patients considered "at risk" by MNA-SF. Malnutrition prevalence was 4.5%, 7.9%, and 17% using ESPEN definitions 1, 2a, and 2b, respectively; 19.3% were malnourished. Prevalence of sarcopenia was 37.5%, of which 90.9% fulfilled ESPEN malnutrition criteria, a significant association (p = 0.02). No differences in biochemical markers were observed between patients with or without malnutrition or sarcopenia.

CONCLUSIONS

ESPEN criteria constitute an appropriate tool to establish a malnutrition diagnosis in post-acute care. Sarcopenia, as defined by EWGSOP, was present in 37.5% of patients, of which 90.9% fulfilled ESPEN criteria; therefore, malnutrition was significantly related to sarcopenia. Additional work is needed to determine further implications of the ESPEN consensus definition.

Mitochondria in the Aging Muscles of Flies and Mice: New Perspectives for Old Characters

Sarcopenia is the loss of muscle mass accompanied by a decrease in muscle strength and resistance and is the main cause of disability among the elderly. Muscle loss begins long before there is any clear physical impact in the senior adult. Despite all this, the molecular mechanisms underlying muscle aging are far from being understood. Recent studies have identified that not only mitochondrial metabolic dysfunction but also mitochondrial dynamics and mitochondrial calcium uptake could be involved in the degeneration of skeletal muscle mass. Mitochondrial homeostasis influences muscle quality which, in turn, could play a triggering role in signaling of systemic aging. Thus, it has become apparent that mitochondrial status in muscle cells could be a driver of whole body physiology and organismal aging. In the present review, we discuss the existing evidence for the mitochondria related mechanisms underlying the appearance of muscle aging and sarcopenia in flies and mice.

Sodium nitrate co-ingestion with protein does not augment postprandial muscle protein synthesis rates in older, type 2 diabetes patients

The age-related anabolic resistance to protein ingestion is suggested to be associated with impairments in insulin-mediated capillary recruitment and postprandial muscle tissue perfusion. The present study investigated whether dietary nitrate co-ingestion with protein improves muscle protein synthesis in older, type 2 diabetes patients. Twenty-four men with type 2 diabetes (72 ± 1 yr, 26.7 ± 1.4 m/kg(2) body mass index, 7.3 ± 0.4% HbA1C) received a primed continuous infusion of l-[ring-(2)H5]phenylalanine and l-[1-(13)C]leucine and ingested 20 g of intrinsically l-[1-(13)C]phenylalanine- and l-[1-(13)C]leucine-labeled protein with (PRONO3) or without (PRO) sodium nitrate (0.15 mmol/kg). Blood and muscle samples were collected to assess protein digestion and absorption kinetics and postprandial muscle protein synthesis rates. Upon protein ingestion, exogenous phenylalanine appearance rates increased in both groups (P < 0.001), resulting in 55 ± 2% and 53 ± 2% of dietary protein-derived amino acids becoming available in the circulation over the 5h postprandial period in the PRO and PRONO3 groups, respectively. Postprandial myofibrillar protein synthesis rates based on l-[ring-(2)H5]phenylalanine did not differ between groups (0.025 ± 0.004 and 0.021 ± 0.007%/h over 0-2 h and 0.032 ± 0.004 and 0.030 ± 0.003%/h over 2-5 h in PRO and PRONO3, respectively, P = 0.7). No differences in incorporation of dietary protein-derived l-[1-(13)C]phenylalanine into de novo myofibrillar protein were observed at 5 h (0.016 ± 0.002 and 0.014 ± 0.002 mole percent excess in PRO and PRONO3, respectively, P = 0.8). Dietary nitrate co-ingestion with protein does not modulate protein digestion and absorption kinetics, nor does it further increase postprandial muscle protein synthesis rates or the incorporation of dietary protein-derived amino acids into de novo myofibrillar protein in older, type 2 diabetes patients.

Oxandrolone Augmentation of Resistance Training in Older Women: A Randomized Trial

INTRODUCTION

Sarcopenia is disproportionately present in older women with disability, and optimum treatment is not clear. We conducted a double-blind, randomized, placebo-controlled trial to determine whether oxandrolone administration in elderly women improves body composition or physical function beyond that which occurs in response to progressive resistance training (PRT).

METHODS

Twenty-nine sedentary women (age 74.9 ± 6.8 yr; 5.9 ± 2.8 medications per day) were randomized to receive high-intensity PRT (three times a week for 12 wk) combined with either oxandrolone (10 mg·d(-1)) or an identical placebo. Peak strength was assessed for leg press, chest press, triceps, knee extension, and knee flexion. Power was assessed for leg press and chest press. Physical function measures included static and dynamic balance, chair rise, stair climb, gait speed, and 6-min walk test. Body composition was assessed using dual energy x-ray absorptiometry.

RESULTS

Oxandrolone treatment augmented increases in lean tissue for the whole body (2.6 kg; 95% confidence interval (CI), 1.0-4.2 kg; P = 0.003), arms (0.3 kg; 95% CI, 0.1-0.5 kg; P = 0.001), legs (0.8 kg; 95% CI, 0.1-1.4 kg; P = 0.018), and trunk (1.4 kg; 95% CI, 0.4-2.3 kg; P = 0.004). Oxandrolone also augmented loss of fat tissue of the whole body (-1 kg; 95% CI, -1.6 to -0.4; P = 0.002), arms (-0.2 kg; 95% CI, -0.5 to -0.02 kg; P = 0.032), legs (-0.4 kg; 95% CI, -0.6 to -0.1; P = 0.009), and tended to reduce trunk fat (-0.4 kg; 95% CI, -0.9 to 0.04; P = 0.07). Improvements in muscle strength and power, chair stand, and dynamic balance were all significant over time (P < 0.05) but not different between groups (P > 0.05).

CONCLUSIONS

Oxandrolone improves body composition adaptations to PRT in older women over 12 wk without augmenting muscle function or functional performance beyond that of PRT alone.

Sarcopenia in patients with heart failure with preserved ejection fraction: Impact on muscle strength, exercise capacity and quality of life

BACKGROUND

To describe the prevalence of sarcopenia in ambulatory patients with heart failure with preserved ejection fraction (HFpEF) and its relation to reduced exercise capacity, muscle strength, and quality of life (QoL).

METHODS AND RESULTS

A total of 117 symptomatic outpatients with HFpEF were prospectively enrolled in Germany, England, and Slovenia as part of the Studies Investigating Co-morbidities Aggravating Heart Failure (SICA-HF). Appendicular skeletal muscle (ASM) mass (the sum of muscle mass in both arms and legs) was assessed by DEXA. Echocardiography, 6-minute walk testing (6-MWT), muscle strength assessment, spiroergometry and QoL evaluation using EQ-5D Questionnaire were performed. Sarcopenia was defined as ASM 2 standard deviations below the mean of a healthy reference group aged 18-40years. Patients were divided into 3 groups according to the E/e' value: ≤8, 9-14, and ≥15. Sarcopenia was detected in 19.7% of all patients. These patients performed worse during 6-MWT (404±116 vs. 307±145m, p=0.003) and showed lower absolute peak oxygen consumption (1579±474 vs. 1211±442mL/min, p<0.05). Both ASM and muscle strength were lowest in patients with E/e' >15 (p<0.05). Higher values of muscle strength/ASM were associated with a better QoL (r=0.5, p<0.0005). Logistic regression showed ASM to be independently associated with reduced distance walked during the 6-MWT adjusted for NYHA, height, left atrium diameter, ferritin and forced expiratory volume in 1s (FEV1) (odds ratio 1.2, p=0.02).

CONCLUSION

Sarcopenia affects a clinically relevant proportion of patients with HFpEF. Low ASM is strongly linked to reduced muscle strength, exercise capacity and QoL in these patients.

Association between Thigh Muscle Volume and Leg Muscle Power in Older Women

The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years) was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628), leg push power (r = 0.550), isometric quadriceps strength (r = 0.442), hand grip strength (r = 0.367), fast gait speed (r = 0.291), habitual gait speed (r = 0.256), body mass index (r = 0.411) and age (r = -0.392). Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.

MicroRNA-Regulated Proinflammatory Cytokines in Sarcopenia

Sarcopenia has been defined as the aging-related disease with the declined mass, strength, and function of skeletal muscle, which is the major cause of frailty and falls in elders. The activation of inflammatory signal pathways due to diseases and aging is suggested to reveal the critical impact on sarcopenia. Several proinflammatory cytokines, especially interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), play crucial roles in modulation of inflammatory signaling pathway during the aging-related loss of skeletal muscle. MicroRNAs (miRNAs) have emerged as the important regulators for the mass and functional maintenance of skeletal muscle through regulating gene expression of proinflammatory cytokines. In this paper, we have systematically discussed regulatory mechanisms of miRNAs for the expression and secretion of inflammatory cytokines during sarcopenia, which will provide some novel targets and therapeutic strategies for controlling aging-related atrophy of skeletal muscle and corresponding chronic inflammatory diseases.

Cardiac cachexia: hic et nunc

Cardiac cachexia (CC) is the clinical entity at the end of the chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely, the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. A better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia, and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

A robust neuromuscular system protects rat and human skeletal muscle from sarcopenia

Declining muscle mass and function is one of the main drivers of loss of independence in the elderly. Sarcopenia is associated with numerous cellular and endocrine perturbations, and it remains challenging to identify those changes that play a causal role and could serve as targets for therapeutic intervention. In this study, we uncovered a remarkable differential susceptibility of certain muscles to age-related decline. Aging rats specifically lose muscle mass and function in the hindlimbs, but not in the forelimbs. By performing a comprehensive comparative analysis of these muscles, we demonstrate that regional susceptibility to sarcopenia is dependent on neuromuscular junction fragmentation, loss of motoneuron innervation, and reduced excitability. Remarkably, muscle loss in elderly humans also differs in vastus lateralis and tibialis anterior muscles in direct relation to neuromuscular dysfunction. By comparing gene expression in susceptible and non-susceptible muscles, we identified a specific transcriptomic signature of neuromuscular impairment. Importantly, differential molecular profiling of the associated peripheral nerves revealed fundamental changes in cholesterol biosynthetic pathways. Altogether our results provide compelling evidence that susceptibility to sarcopenia is tightly linked to neuromuscular decline in rats and humans, and identify dysregulation of sterol metabolism in the peripheral nervous system as an early event in this process.

Evaluation of C-terminal Agrin Fragment as a marker of muscle wasting in patients after acute stroke during early rehabilitation

BACKGROUND

C-terminal Agrin Fragment (CAF) has been proposed as a novel biomarker for sarcopenia originating from the degeneration of the neuromuscular junctions. In patients with stroke muscle wasting is a common observation that predicts functional outcome. We aimed to evaluate agrin sub-fragment CAF22 as a marker of decreased muscle mass and physical performance in the early phase after acute stroke.

METHODS

Patients with acute ischaemic or haemorrhagic stroke (n = 123, mean age 70 ± 11 y, body mass index BMI 27.0 ± 4.9 kg/m(2)) admitted to inpatient rehabilitation were studied in comparison to 26 healthy controls of similar age and BMI. Functional assessments were performed at begin (23 ± 17 days post stroke) and at the end of the structured rehabilitation programme (49 ± 18 days post stroke) that included physical assessment, maximum hand grip strength, Rivermead motor assessment, and Barthel index. Body composition was assessed by bioelectrical impedance analysis (BIA). Serum levels of CAF22 were measured by ELISA.

RESULTS

CAF22 levels were elevated in stroke patients at admission (134.3 ± 52.3 pM) and showed incomplete recovery until discharge (118.2 ± 42.7 pM) compared to healthy controls (95.7 ± 31.8 pM, p < 0.001). Simple regression analyses revealed an association between CAF22 levels and parameters of physical performance, hand grip strength, and phase angle, a BIA derived measure of the muscle cellular integrity. Improvement of the handgrip strength of the paretic arm during rehabilitation was independently related to the recovery of CAF22 serum levels only in those patients who showed increased lean mass during the rehabilitation.

CONCLUSIONS

CAF22 serum profiles showed a dynamic elevation and recovery in the subacute phase after acute stroke. Further studies are needed to explore the potential of CAF22 as a serum marker to monitor the muscle status in patients after stroke.

Aging Reduces the Activation of the mTORC1 Pathway after Resistance Exercise and Protein Intake in Human Skeletal Muscle: Potential Role of REDD1 and Impaired Anabolic Sensitivity

This study was designed to better understand the molecular mechanisms involved in the anabolic resistance observed in elderly people. Nine young (22 ± 0.1 years) and 10 older (69 ± 1.7 years) volunteers performed a one-leg extension exercise consisting of 10 × 10 repetitions at 70% of their 3-RM, immediately after which they ingested 30 g of whey protein. Muscle biopsies were taken from the vastus lateralis at rest in the fasted state and 30 min after protein ingestion in the non-exercised (Pro) and exercised (Pro+ex) legs. Plasma insulin levels were determined at the same time points. No age difference was measured in fasting insulin levels but the older subjects had a 50% higher concentration than the young subjects in the fed state (p < 0.05). While no difference was observed in the fasted state, in response to exercise and protein ingestion, the phosphorylation state of PKB (p < 0.05 in Pro and Pro+ex) and S6K1 (p = 0.059 in Pro; p = 0.066 in Pro+ex) was lower in the older subjects compared with the young subjects. After Pro+ex, REDD1 expression tended to be higher (p = 0.087) in the older group while AMPK phosphorylation was not modified by any condition. In conclusion, we show that the activation of the mTORC1 pathway is reduced in skeletal muscle of older subjects after resistance exercise and protein ingestion compared with young subjects, which could be partially due to an increased expression of REDD1 and an impaired anabolic sensitivity.

New Predictive Index for Lumbar Paraspinal Muscle Degeneration Associated With Aging

STUDY DESIGN

A cross-sectional imaging study of paraspinal muscle degeneration using a new index for easy evaluation.

OBJECTIVE

To examine the natural progression of age-related changes in the lumbar paraspinal muscles and to verify the validity of our new index for evaluating paraspinal muscle degenerationSUMMARY OF BACKGROUND DATA.: Measurement of paraspinal muscle morphology is an effective method for reflecting atrophy and fat infiltration, but it is complicated to perform. Therefore, we focused on the groove between lumbar paraspinal muscles as a simple index for evaluating paraspinal muscle degeneration.

METHODS

A total of 160 subjects aged 10 to 88 years (10 male and 10 female subjects in each decade) with lumbar lordosis of more than 20° were included. Body mass index (BMI) was calculated. Sagittal T2-weighted magnetic resonance imaging (MRI) was used to measure lumbar lordosis, while axial T2-weighted MRI was used to measure cross-sectional area (CSA) and fat infiltration rate of the paraspinal muscles at the intervertebral disc level from L1 to L5. To quantify the depth of the groove between the paraspinal muscles, our own image index (lumbar indentation value (LIV): equal to the length of the bulge of the muscle to the attachment of the spinous process), also was measured. We then determined the correlation between LIV and paraspinal muscle degeneration.

RESULTS

There were no significant differences in BMI and lumbar lordosis between age groups. CSA of the paraspinal muscles tended to decrease with age, and fat infiltration rate increased with age. There was a negative correlation between CSA and fat infiltration rate at all levels (r = -0.474 to -0.634). LIV decreased significantly with age and strongly correlated with CSA at all levels (r = 0.709-0.789).

CONCLUSION

Our new index is a simple and effective parameter for evaluating paraspinal muscle degeneration associated with aging.

LEVEL OF EVIDENCE

4.