Healthy community-living older men differ from women in associations between myostatin levels and skeletal muscle mass

DNA methylation of skeletal muscle function-related secretary factors identifies FGF2 as a potential biomarker for sarcopenia

BACKGROUND

Sarcopenia is characterized by progressive loss of muscle mass and function due to aging. DNA methylation has been identified to play important roles in the dysfunction of skeletal muscle. The aim of our present study was to explore the whole blood sample-based methylation changes of skeletal muscle function-related factors in patients with sarcopenia.

METHODS

The overall DNA methylation levels were analysed by using MethlTarget™ DNA Methylation Analysis platform in a discovery set consistent of 50 sarcopenic older adults (aged ≥65 years) and 50 age- and sex-matched non-sarcopenic individuals. The candidate differentially methylated regions (DMRs) were further validated by Methylation-specific PCR (MSP) in another two independent larger sets and confirmed by pyrosequencing. Receiver operating characteristic (ROC) curve analysis was used to determine the optimum cut-off levels of fibroblast growth factor 2 (FGF2)_30 methylation best predicting sarcopenia and area under the ROC curve (AUC) was measured. The correlation between candidate DMRs and the risk of sarcopenia was investigated by univariate analysis and multivariate logistic regression analysis.

RESULTS

Among 1149 cytosine-phosphate-guanine (CpG) sites of 27 skeletal muscle function-related secretary factors, 17 differentially methylated CpG sites and 7 differentially methylated regions (DMRs) were detected between patients with sarcopenia and control subjects in the discovery set. Further methylation-specific PCR identified that methylation of fibroblast growth factor 2 (FGF2)_30 was lower in patients with sarcopenia and the level was decreased as the severity of sarcopenia increased, which was confirmed by pyrosequencing. Correlation analysis demonstrated that the methylation level of FGF2_30 was positively correlated to ASMI (r = 0.372, P < 0.001), grip strength (r = 0.334, P < 0.001), and gait speed (r = 0.411, P < 0.001). ROC curve analysis indicated that the optimal cut-off value of FGF2_30 methylation level that predicted sarcopenia was 0.15 with a sensitivity of 84.6% and a specificity of 70.1% (AUC = 0.807, 95% CI = 0.756-0.858, P < 0.001). Multivariate logistic regression analyses showed that lower FGF2_30 methylation level (<0.15) was significantly associated with increased risk of sarcopenia even after adjustment for potential confounders including age, sex, and BMI (adjusted OR = 9.223, 95% CI: 6.614-12.861, P < 0.001).

CONCLUSIONS

Our results suggest that lower FGF2_30 methylation is correlated with the risk and severity of sarcopenia in the older adults, indicating that FGF2 methylation serve as a surrogate biomarker for the screening and evaluation of sarcopenia.

A low baseline serum myostatin concentration is associated with poor clinical outcome in patients with primary biliary cholangitis

BACKGROUND AND AIM

Primary biliary cholangitis (PBC) is an autoimmune-mediated cholestatic liver disease that can progress to biliary cirrhosis and liver-related death. The associations between baseline myostatin levels and clinical outcomes in PBC patients are unknown. We aimed to clarify the influence of myostatin levels on the clinical outcomes of PBC patients.

METHODS

A total of 119 PBC patients were analyzed in this study. Myostatin levels were measured in stored sera before ursodeoxycholic acid treatment, and their associations with the clinical features and prognosis of PBC patients were analyzed. We analyzed the correlation between serum myostatin and chemokines/cytokines.

RESULTS

Serum myostatin was significantly lower in PBC patients (2343 pg/mL) than in healthy controls (4059 pg/mL, P < 0.001). The prevalence of patients with low myostatin levels increased according to the severity of histological fibrosis. The serum myostatin concentration was negatively correlated with the IL-6 and leucine-rich α2 glycoprotein levels, but the chemokine concentration was not correlated with the myostatin concentration. Low myostatin in PBC patients was associated with shorter survival without liver-related complications (hazard ratio [HR], 3.598; 95% confidence interval [CI], 1.27-10.1; P = 0.015) and shorter transplant-free survival (HR, 3.129; 95% CI, 1.02-9.56; P = 0.045) independent of pretreatment GLOBE score. Patients with both high pretreatment GLOBE scores and low myostatin levels had poor prognoses (log-rank test: P < 0.001).

CONCLUSIONS

A low serum myostatin concentration at diagnosis was associated with poor clinical outcomes. Assessment of circulating myostatin levels may improve the prediction of outcomes in patients with PBC.

Effectiveness of resistance training in modulating inflammatory biomarkers among Asian patients with sarcopenia: a systematic review and meta-analysis of randomized controlled trials

Objective

Given the high incidence of sarcopenia among Asians, it is imperative to identify appropriate intervention methods. The International Clinical Practice Guidelines for Sarcopenia, developed by the International Conference on Sarcopenia and Frailty Research (ICFSR) task force, recommends resistance training (RT) as a primary treatment for managing sarcopenia. Inflammatory biomarkers serve as indicators of sarcopenia. However, there is currently insufficient conclusive evidence regarding the effectiveness of RT in modulating inflammatory biomarker levels among Asian participants with sarcopenia.

Data sources

Four databases were utilized for this study until October 9, 2023. This study focused on randomized controlled trials (RCTs) that examined the effects of RT on interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and interleukin-10 (IL-10) about sarcopenia. This study has been registered in the PROSPERO database (CRD42024501855).

Results

The meta-analysis included six studies from Asians involving 278 participants. The results showed a significant decrease in RT for IL-6 (weighted mean difference (WMD) = -0.73, 95% confidence interval (CI) = -1.02 to -0.44; n=5). However, no significant differences were found for TNF-α (WMD = -1.00, 95% CI = -2.47 to 0.46; n=5), CRP (WMD = -0.45, 95% CI = -1.14 to 0.23; n=3), and IL-10 (WMD = 0.13, 95% CI = -3.99 to 4.25; n=2). Subgroup analysis revealed that factors including gender selection, intervention methods, frequency, period, and duration could have a particular effect on the part of inflammatory biomarkers.

Conclusion

RT has been shown to reduce part of the level of inflammatory markers, specifically IL-6, in Asian sarcopenia participants. However, other inflammatory factors, such as TNF-α, CRP, and IL-10, did not show significant changes. Further research should confirm the impact of RT on these indicators and explore the potential effects of various factors on different inflammatory markers, such as diet, body composition, and medications.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=501855, identifier CRD42024501855.

Protein-enriched soup and weekly exercise improve muscle health: A randomized trial in mid-to-old age with inadequate protein intake

BACKGROUND

Prior research has highlighted the synergistic impact of protein supplementation on muscle function post-exercise in adults; however, evidence supporting the combined effects were less robust and inconsistent on those with protein insufficiency. This investigation aims to explore efficacy of protein-enriched soup coupled with exercise on muscle health and metabolism in middle-aged and older adults with suboptimal protein intake.

METHODS

An open-label, 12-week, randomized controlled trial involving participants with insufficient protein intake (<1.0 g/kg/day) was done. The intervention group consumed protein-enriched soup (24-30 g protein daily) and 1-h weekly exercise, while controls received health education. Assessments included laboratory tests, functional assessments, and body composition.

RESULTS

In this trial, 97 out of 100 randomized participants (mean age: 64.65 ± 4.84 years, 81.8% female) completed the study (47 in intervention group and 50 in control group). Compared results of baselines, at 1 and 3 months of intervention, significant improvements in waist circumference (83.48 ± 10.22 vs. 82.5 ± 9.88 vs. 82.37 ± 9.42 cm, P for trend = 0.046), 6-min walking distance (525.65 ± 58.46 vs. 534.47 ± 51.87 vs. 552.02 ± 57.66 m, P for trend = 0.001), five-time sit-to-stand time (7.63 ± 1.63 vs. 6.81 ± 1.8 vs. 6.4 ± 1.42 s, P for trend <0.001), grip strength (26.74 ± 6.54 vs. 27.53 ± 6.99 vs. 28.52 ± 7.09 kg, P for trend <0.001), and MNA score (26.8 ± 2.14 vs. 27.73 ± 1.74 vs. 27.55 ± 1.72, P for trend <0.001) were discerned within the intervention group. The intervention demonstrated a significant reduction in serum triglyceride (105.32 ± 49.84 vs. 101.36 ± 42.58 vs. 93.43 ± 41.49 mg/dL, P for trend = 0.023), increased HDL-C (60.04 ± 16.21 vs. 60 ± 17.37 vs. 62.55 ± 18.27 mg/dL, P for trend = 0.02), and DHEA-S levels (97.11 ± 54.39 vs. 103.39 ± 56.75 vs. 106.83 ± 60.56 μg/dL, P for trend = 0.002). Serum myostatin did not differ in both groups, but serum leptin levels significantly increased (9118.88 ± 5811.68 vs. 11508.97 ± 7151.08 vs. 11220.80 ± 7190.71 pg/mL, P for trend = 0.016) in controls. The intervention group showed greater improvements in 6 min walking distance (β = 0.71, 95% CI: 6.88 to 40.79, P = 0.006), five-time sit-to-stand test (β = -0.87, 95% CI: -1.59 to -0.15, P = 0.017), MNA score (β = 0.96, 95% CI: 0.20 to 1.71, P = 0.013), serum triglycerides (β = -15.01, 95% CI: -27.83 to -2.20, P = 0.022), LDL-C (β = -9.23, 95% CI: -16.98 to -1.47, P = 0.020), and DHEA-S levels (β = 9.98, 95% CI: 0.45 to 19.51, P = 0.04) than controls.

CONCLUSIONS

Protein-enriched soup with weekly exercise over 12 weeks significantly improved physical performance, lipid profile, and DHEA-S levels among middle-aged and older adults with inadequate protein intake, while studies assessing long-term benefits of the intervention are needed.

Role of irisin and myostatin on sarcopenia in malnourished patients diagnosed with GLIM criteria

OBJECTIVES

Sarcopenia is characterized by the loss of muscle mass. Skeletal muscle can produce and secrete different molecules called myokines. Irisin and myostatin are antagonistic myokines, and to our knowledge, no studies of both myokines have been conducted in patients with disease-related malnutrition (DRM). This study aimed to investigate the role of circulating irisin and myostatin in sarcopenia in patients with DRM.

METHODS

The study included 108 outpatients with DRM according to the Global Leadership Initiative on Malnutrition criteria. Participants had a mean age of 67.4 ± 3.4 y. Anthropometric data, muscle mass by ultrasound at the rectus femoris quadriceps (RFQ) level, impedancemetry (skeletal muscle mass [SMM], appendicular SMM [aSMM], and aSMM index [aSMMI]), dynamometry, biochemical parameters, dietary intake, circulating irisin and myostatin levels were determined in all patients. Confirmed sarcopenia was diagnosed as criteria of probable sarcopenia (low muscle strength) plus abnormal aSMMI.

RESULTS

Of the 108 patients, 44 presented sarcopenia (41%); 64 did not present with the disorder (59%). The following parameters were worse in patients with sarcopenia: Patients without sarcopenia were stronger than those with the disorder (7.9 ±1.3 kg; P = 0.01). Circulating irisin levels were higher in patients without sarcopenia than those with sarcopenia (651.3 ± 221.3 pg/mL; P =0.01). Myostatin levels were similar in both groups. Finally, logistic regression analysis reported a low risk for sarcopenia (odds ratio, 0.39; 95% confidence interval, 0.19-0.92; P = 0.03) in high irisin median levels as a dichotomic parameter after adjusting for body mass index, sex, energy intake, and age.

CONCLUSION

The present study reported that low levels of serum irisin were closely associated with sarcopenia in patients with DRM.

Sex differences in the frailty phenotype and mortality in the I-Lan longitudinal aging study cohort

BACKGROUND

Frailty is a common geriatric syndrome related to multiple adverse outcomes. Sex differences in its prevalence and impact on mortality remain incompletely understood.

METHODS

This study was conducted with data from the I-Lan Longitudinal Aging Study, in which community-dwelling subjects aged > 50 years without coronary artery disease or diabetes were enrolled. Sex disparities in phenotypically defined frailty and sex-morality predictor interactions were evaluated. Sex- and frailty-stratified analyses of mortality were performed.

RESULTS

The sample comprised 1371 subjects (51.4% women, median age 61 years). The median follow-up period was 6.3 (interquartile range, 5.8-7.0) years. The frailty prevalence did not differ between men (5.3%) and women (5.8%). Frail individuals were older and less educated and had poorer renal function than did non-frail individuals. Body composition trends differed between sexes, regardless of frailty. Relative to non-frail men, frail men had significantly lower body mass indices (BMIs; 24.5 vs. 23.4 kg/m2, p = 0.04) and relative appendicular skeletal muscle masses (7.87 vs. 7.05 kg/m2, p < 0.001). Frail women had significantly higher BMIs (25.2 vs. 23.9 kg/m2, p = 0.02) and waist circumferences (88 vs. 80 cm, p < 0.001) than did non-frail women. Frailty was an independent mortality predictor for men only [hazard ratio (95% confidence interval) = 3.395 (1.809-6.371), psex-frailty interaction = 0.03].

CONCLUSION

Frailty reflected poorer health in men than in women in the present cohort. This study revealed sex disparities in the impact of frailty on mortality among relatively healthy community-dwelling older adults.

Navigating sarcopenia in COVID-19 patients and survivors: Understanding the long-term consequences, transitioning from hospital to community with mechanisms and interventions for future preparedness

The coronavirus disease 2019 (COVID-19) pandemic has caused widespread devastation, with millions of confirmed cases and deaths worldwide. Although there were efforts made to develop treatments and vaccines for COVID-19, the coexistence of sarcopenia, a muscle disorder, has been largely overlooked. It is while new variants of this disease (eg, BA.2.86) are challenging the current protocols. Sarcopenia is associated with increased mortality and disability, and shares common mechanisms with COVID-19, such as inflammation, hormonal changes, and malnutrition. This can worsen the effects of both conditions. Furthermore, survived patients with COVID-19 who have elevated risk, as well as aging, which increases the process of sarcopenia. Therefore, addressing sarcopenia in patients with COVID-19 and surviving individuals can be crucial for improving outcomes and preventing long-term disability. During hospital stays, assessing sarcopenia through indicators like muscle wasting and malnutrition is important. Nutritional interventions, such as malnutrition screening and enteral feeding, play a critical role in preventing sarcopenia in hospitals. Mental health and physical activity evaluations and interventions are also necessary. Even after recovering from COVID-19, there is a risk of developing sarcopenia, requiring continued monitoring. Nutrition and physical activity considerations are vital for prevention and management, necessitating tailored training programs and diet therapy. Mental health should not be overlooked, with regular screening, and community-based interventions. Infrastructure should support physical activity, and mental health services must become more accessible. Community engagement through support groups and peer networks can foster resilience and social connection. Efforts are needed to promote healthy diets and ensure access to nutritious foods.

Development of multiple biomarker panels for prediction of sarcopenia in community-dwelling older adults

BACKGROUND

It is required to consider multiple biomarkers simultaneously to predict sarcopenia and to understand its complex pathological mechanisms. This study aimed to develop multiple biomarker panels for predicting sarcopenia in older adults and to further examine its association with the incidence of sarcopenia.

METHODS

A total of 1,021 older adults were selected from the Korean Frailty and Aging Cohort Study. Sarcopenia was defined by the Asian Working Group for Sarcopenia 2019 criteria. Among the 14 biomarker candidates at baseline, eight biomarkers that could optimally detect individuals with sarcopenia were selected to develop a multi-biomarker risk score (range from 0 to 10). The utility of developed multi-biomarker risk score in discriminating sarcopenia was investigated using receiver operating characteristic (ROC) analysis.

RESULTS

The multi-biomarker risk score had an area under the ROC curve (AUC) of 0.71 with an optimal cut-off of 1.76 score, which was significantly higher than all single biomarkers with AUC of <0.7 (all, p<0.01). During the two-year follow-up, the incidence of sarcopenia was 11.1%. Continuous multi-biomarker risk score was positively associated with incidence of sarcopenia after adjusting confounders (odds ratio [OR]=1.63; 95% confidence interval [CI]=1.23-2.17). Participants with a high risk score had higher odds of sarcopenia than those with a low risk score (OR=1.82; 95% CI=1.04-3.19).

CONCLUSIONS

Multi-biomarker risk score, which was a combination of eight biomarkers with different pathophysiologies, better discriminated the presence of sarcopenia than a single biomarker, and it could further predict the incidence of sarcopenia over two years in older adults.

Muscle-bone crosstalk via endocrine signals and potential targets for osteosarcopenia-related fracture

Background

Osteosarcopenia is a syndrome coexisting sarcopenia and osteopenia/osteoporosis, with a high fracture risk. Recently, skeletal muscle and bone have been recognized as endocrine organs capable of communication through secreting myokines and osteokines, respectively. With a deeper understanding of the muscle-bone crosstalk, these endocrine signals exhibit an important role in osteosarcopenia development and fracture healing.

Methods

This review summarizes the role of myokines and osteokines in the development and treatment of osteosarcopenia and fracture, and discusses their potential for osteosarcopenia-related fracture treatment.

Results

Several well-defined myokines (myostatin and irisin) and osteokines (RANKL and SOST) are found to not only regulate skeletal muscle and bone metabolism but also influence fracture healing processes. Systemic interventions targeting these biochemical signals has shown promising results in improving the mass and functions of skeletal muscle and bone, as well as accelerating fracture healing processes.

Conclusion

The regulation of muscle-bone crosstalk via biochemical signals presents a novel and promising strategy for treating osteosarcopenia and fracture by simultaneously enhancing bone and muscle anabolism. We propose that myostatin, irisin, RANKL, and SOST may serve as potential targets to treat fracture patients with osteosarcopenia.

The translational potential of this article

Osteosarcopenia is an emerging geriatric syndrome where sarcopenia and osteoporosis coexist, with high fracture risk, delayed fracture healing, and increased mortality. However, no pharmacological agent is available to treat fracture patients with osteosarcopenia. This review summarizes the role of several myokines and osteokines in the development and treatment of osteosacropenia and fracture, as well as discusses their potential as intervention targets for osteosarcopenia-related fracture, which provides a novel and promising strategy for future osteosarcopenia-related fracture treatment.

Mechanisms of sarcopenia in liver cirrhosis and the role of myokines

Sarcopenia is a syndrome characterized by a decline in skeletal muscle quantity and/or quality, strength and performance, leading to unfortunate events, such as injurious falls or even death. It is not identical to frailty and malnutrition, even though there is a significant overlap among these syndromes. In patients with liver cirrhosis (LC), sarcopenia is classified as secondary and has been associated with increased morbidity and mortality during the pre- and post-transplantation period. It can be a result of malnutrition, hyperammonemia, low physical activity, endocrine abnormalities, accelerated starvation, metabolic disturbances, altered gut function leading to chronic inflammation, and alcohol abuse. Myokines are peptides mainly synthesized by contracting muscle and adipose tissue cells and may play a key role in the pathophysiology of sarcopenia. More than a hundred myokines have been recognized, but only a few have been investigated. They can be classified as negative regulators, such as myostatin, tumor growth factor-β, activins, growth differentiation factor-11, and positive regulators of muscle growth including follistatin, bone morphogenic proteins, and irisin. So far, only myostatin, follistatin, irisin and decorin have been studied in LC-associated sarcopenia. In this review, we focused on the mechanisms of cirrhosis-related sarcopenia and the role of myokines that have already been studied in the literature, either as markers helping in the diagnostic evaluation of sarcopenia, or as prognostic factors of survival. Standard therapeutic options to prevent or treat sarcopenia in LC are also being reported, as well as the possible therapeutic implication of myokines.

The effects of resistance training on myostatin and follistatin in adults: A systematic review and meta-analysis

INTRODUCTION AND AIM

Myostatin and follistatin are the main hormones for regulating muscle mass, and previous research suggests they are modulated by resistance training. We therefore performed a systematic review and meta-analysis to investigate the impact of resistance training on circulating myostatin and follistatin in adults.

METHODS

A search was conducted in PubMed and Web of science from inception until October 2022 to identify original studies investigating the effects of resistance training compared with controls that did not exercise. Standardized mean differences and 95% confidence intervals (CIs) were calculated using random effects models.

RESULTS

A total 26 randomized studies, including 36 interventions, and involving 768 participants (aged ∼18 to 82 years), were included in the meta-analysis. Resistance training effectively decreased myostatin [-1.31 (95% CI -1.74 to -0.88, p=0.001, 26 studies] and increased follistatin [2.04 (95% CI: 1.51 to 2.52), p=0.001, 14 studies]. Subgroup analyses revealed a significant decrease in myostatin and increase in follistatin regardless of age.

CONCLUSION

Resistance training in adults is effective for reducing myostatin and increasing follistatin which may contribute to the beneficial effects of resistance training on muscle mass and metabolic outcomes.

A Phase 1 study for safety and pharmacokinetics of BIO101 (20-hydroxyecdysone) in healthy young and older adults

BACKGROUND

Sarcopenia is an age-related skeletal muscle disorder characterized by loss of muscle mass and strength leading to mobility disability. 20-Hydroxyecdysone (20E) is a polyhydroxylated plant steroid that demonstrates pharmacological effects in many disease animal models including ageing/sarcopenia. BIO101 is a 20E purified investigational drug (≥97%) that previously demonstrated good toxicology profiles in rat and dog. BIO101 is evaluated in healthy young and older adults in a Phase 1 study.

METHODS

This study is a Single Ascending Dose (SAD) followed by a 14-day Multiple Ascending Dose (MAD). In SAD, BIO101 was administered orally to 16 young adults at doses from 100 to 1400 mg and to 8 older adults (age ≥65 years) at 1400 mg. In MAD, doses of 350 mg once daily (qd), 350 mg twice daily (bid) and 450 mg bid were administered to 10 older adults. The primary objective was to evaluate safety and pharmacokinetics (PK), including dosing of circulating metabolites. Pharmacodynamic effects were investigated with regard to myostatin, procollagen-III-amino-terminal propeptide (PIIINP), myoglobin, creatine-kinase Muscle Brain (CKMB), renin and aldosterone plasma/serum levels.

RESULTS

BIO101 showed a good safety profile with only mild to moderate adverse events and a satisfactory pharmacokinetic profile. In SAD, at 100 mg to 1400 mg, mean Cmax and areas under the curve increased less than dose-proportionally. Mean half-life was short (2.4-4.9 h), and mean renal clearance was comparable in all doses (4.05-5.05 L/h). Mean plasma exposure was slightly lower in older adults (22% lower for Cmax and 13%-15% lower for AUCs) compared with young subjects. In MAD, 350 and 450 mg bid led to a slight accumulation over 14 days (mean ratio of accumulation [Rac] of 1.31 in both cohorts). Reduction of biomarkers (myoglobin, CK-MB) mean serum levels (vs. baseline) was observed at 450 mg bid. Two major metabolites of 20E (14-deoxy-20-hydroxyecdysone and 14-deoxypoststerone) were identified and quantified.

CONCLUSIONS

BIO101 shows a good safety and pharmacokinetic profile that led to the selection of doses for the subsequent interventional clinical trials of Phase 2 in age-related sarcopenia (SARA-INT) and Phase 3 in Covid-19 (COVA).

Sex Differences in Inflammation and Muscle Wasting in Aging and Disease

Only in recent years, thanks to a precision medicine-based approach, have treatments tailored to the sex of each patient emerged in clinical trials. In this regard, both striated muscle tissues present significant differences between the two sexes, which may have important consequences for diagnosis and therapy in aging and chronic illness. In fact, preservation of muscle mass in disease conditions correlates with survival; however, sex should be considered when protocols for the maintenance of muscle mass are designed. One obvious difference is that men have more muscle than women. Moreover, the two sexes differ in inflammation parameters, particularly in response to infection and disease. Therefore, unsurprisingly, men and women respond differently to therapies. In this review, we present an up-to-date overview on what is known about sex differences in skeletal muscle physiology and disfunction, such as disuse atrophy, age-related sarcopenia, and cachexia. In addition, we summarize sex differences in inflammation which may underly the aforementioned conditions because pro-inflammatory cytokines deeply affect muscle homeostasis. The comparison of these three conditions and their sex-related bases is interesting because different forms of muscle atrophy share common mechanisms; for instance, those responsible for protein dismantling are similar although differing in terms of kinetics, severity, and regulatory mechanisms. In pre-clinical research, exploring sexual dimorphism in disease conditions could highlight new efficacious treatments or recommend implementation of an existing one. Any protective factors discovered in one sex could be exploited to achieve lower morbidity, reduce the severity of the disease, or avoid mortality in the opposite sex. Thus, the understanding of sex-dependent responses to different forms of muscle atrophy and inflammation is of pivotal importance to design innovative, tailored, and efficient interventions.

Serum transthyretin and aminotransferases are associated with lean mass in people with coronary heart disease: Further insights from the CARE-CR study

Background

Low muscle mass disproportionately affects people with coronary heart disease compared to healthy controls but is under-researched and insufficiently treated. Inflammation, poor nutrition, and neural decline might contribute to low muscle mass. This study aimed to assess circulatory biomarkers related to these mechanisms [albumin, transthyretin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and C-terminal agrin fragment] and their relationship with muscle mass in people with coronary heart disease. Our findings could be beneficial to indicate mechanisms of sarcopenia, detect sarcopenia, and evaluate treatment.

Methods

Serum blood samples from people with coronary heart disease were analysed for biomarker concentrations using enzyme-linked immunosorbent assays. Skeletal muscle mass was estimated using dual X-ray absorptiometry derived appendicular lean mass and reported as skeletal muscle index (SMI; kg m^-2), and as a proportion of total body mass [appendicular skeletal mass (ASM%)]. Low muscle mass was defined as a SMI <7.0 and <6.0 kg m^-2, or ASM% <25.72 and <19.43% for men and women, respectively. Associations between biomarkers and lean mass were adjusted for age and inflammation.

Results

Sixty-four people were assessed; 14 (21.9%) had low muscle mass. People with low muscle mass had lower transthyretin (effect size 0.34, p = 0.007), ALT (effect size 0.34, p = 0.008), and AST (effect size 0.26, p = 0.037) concentrations, compared to those with normal muscle mass. SMI was associated with inflammation-corrected ALT (r = 0.261, p = 0.039) and with inflammation- and age-adjusted AST/ALT ratio (r = -0.257, p = 0.044). Albumin and C-terminal agrin fragment were not associated with muscle mass indices.

Conclusion

Circulatory transthyretin, ALT and AST were associated with low muscle mass in people with coronary heart disease. Low concentrations of these biomarkers might indicate that low muscle mass is partially explained by poor nutrition and high inflammation in this cohort. Targeted treatments to address these factors could be considered for people with coronary heart disease.

Are Skeletal Muscle Changes during Prolonged Space Flights Similar to Those Experienced by Frail and Sarcopenic Older Adults?

Microgravity exposure causes several physiological and psychosocial alterations that challenge astronauts' health during space flight. Notably, many of these changes are mostly related to physical inactivity influencing different functional systems and organ biology, in particular the musculoskeletal system, dramatically resulting in aging-like phenotypes, such as those occurring in older persons on Earth. In this sense, sarcopenia, a syndrome characterized by the loss in muscle mass and strength due to skeletal muscle unloading, is undoubtedly one of the most critical aging-like adverse effects of microgravity and a prevalent problem in the geriatric population, still awaiting effective countermeasures. Therefore, there is an urgent demand to identify clinically relevant biological markers and to underline molecular mechanisms behind these effects that are still poorly understood. From this perspective, a lesson from Geroscience may help tailor interventions to counteract the adverse effects of microgravity. For instance, decades of studies in the field have demonstrated that in the older people, the clinical picture of sarcopenia remarkably overlaps (from a clinical and biological point of view) with that of frailty, primarily when referred to the physical function domain. Based on this premise, here we provide a deeper understanding of the biological mechanisms of sarcopenia and frailty, which in aging are often considered together, and how these converge with those observed in astronauts after space flight.

Energy metabolism and frailty: The potential role of exercise-induced myokines - A narrative review

Frailty is a complex condition that emerges from dysregulation in multiple physiological systems. Increasing evidence suggests the potential role of age-related energy dysregulation as a key driver of frailty. Exercise is considered the most efficacious intervention to prevent and even ameliorate frailty as it up-tunes and improves the function of several related systems. However, the mechanisms and molecules responsible for these intersystem benefits are not fully understood. The skeletal muscle is considered a secretory organ with endocrine functions that can produce and secrete exercise-related molecules such as myokines. These molecules are cytokines and other peptides released by muscle fibers in response to acute and/or chronic exercise. The available evidence supports that several myokines can elicit autocrine, paracrine, or endocrine effects, partly mediating inter-organ crosstalk and also having a critical role in improving cardiovascular, metabolic, immune, and neurological health. This review describes the current evidence about the potential link between energy metabolism dysregulation and frailty and provides a theoretical framework for the potential role of myokines (via exercise) in counteracting frailty. It also summarizes the physiological role of selected myokines and their response to different acute and chronic exercise protocols in older adults.

Inflammaging: Implications in Sarcopenia

In a world in which life expectancy is increasing, understanding and promoting healthy aging becomes a contemporary demand. In the elderly, a sterile, chronic and low-grade systemic inflammation known as "inflammaging" is linked with many age-associated diseases. Considering sarcopenia as a loss of strength and mass of skeletal muscle related to aging, correlations between these two terms have been proposed. Better knowledge of the immune system players in skeletal muscle would help to elucidate their implications in sarcopenia. Characterizing the activators of damage sensors and the downstream effectors explains the inference with skeletal muscle performance. Sarcopenia has also been linked to chronic diseases such as diabetes, metabolic syndrome and obesity. Implications of inflammatory signals from these diseases negatively affect skeletal muscle. Autophagic mechanisms are closely related with the inflammasome, as autophagy eliminates stress signaling sent by damage organelles, but also acts with an immunomodulatory function affecting immune cells and cytokine release. The use of melatonin, an antioxidant, ROS scavenger and immune and autophagy modulator, or senotherapeutic compounds targeting senescent cells could represent strategies to counteract inflammation. This review aims to present the many factors regulating skeletal muscle inflammaging and their major implications in order to understand the molecular mechanisms involved in sarcopenia.

Association of Myostatin Gene Polymorphisms with Strength and Muscle Mass in Athletes: A Systematic Review and Meta-Analysis of the MSTN rs1805086 Mutation

Polymorphism (rs1805086), c.458A>G, p.Lys(K)153Arg(R), (K153R) of the myostatin gene (MSTN) has been associated with a skeletal muscle phenotype (hypertrophic response in muscles due to strength training). However, there are not enough reliable data to demonstrate whether MSTN rs1805086 K and R allelic variants are valid genetic factors that can affect the strength phenotype of athletes' skeletal muscles. The aim is to conduct a systematic review and meta-analysis of the association of MSTN rs1805086 polymorphism with the strength phenotype of athletes. This study analyzed 71 research articles on MSTN and performed a meta-analysis of MSTN K153R rs1805086 polymorphism in strength-oriented athletes and a control (non-athletes) group. It was found that athletes in the strength-oriented athlete group had a higher frequency of the R minor variant than that in the control group (OR = 2.02, P = 0.05). Thus, the obtained results convincingly demonstrate that there is an association between the studied polymorphism and strength phenotype of athletes; therefore, further studies on this association are scientifically warranted.

The Role of Crosstalk between Adipose Cells and Myocytes in the Pathogenesis of Sarcopenic Obesity in the Elderly

As a result of aging, body composition changes, with a decline in muscle mass and an increase in adipose tissue (AT), which reallocates from subcutaneous to visceral depots and stores ectopically in the liver, heart and muscles. Furthermore, with aging, muscle and AT, both of which have recognized endocrine activity, become dysfunctional and contribute, in the case of positive energy balance, to the development of sarcopenic obesity (SO). SO is defined as the co-existence of excess adiposity and low muscle mass and function, and its prevalence increases with age. SO is strongly associated with greater morbidity and mortality. The pathogenesis of SO is complex and multifactorial. This review focuses mainly on the role of crosstalk between age-related dysfunctional adipose and muscle cells as one of the mechanisms leading to SO. A better understanding of this mechanisms may be useful for development of prevention strategies and treatments aimed at reducing the occurrence of SO.

Myostatin and its Regulation: A Comprehensive Review of Myostatin Inhibiting Strategies

Myostatin (MSTN) is a well-reported negative regulator of muscle growth and a member of the transforming growth factor (TGF) family. MSTN has important functions in skeletal muscle (SM), and its crucial involvement in several disorders has made it an important therapeutic target. Several strategies based on the use of natural compounds to inhibitory peptides are being used to inhibit the activity of MSTN. This review delivers an overview of the current state of knowledge about SM and myogenesis with particular emphasis on the structural characteristics and regulatory functions of MSTN during myogenesis and its involvements in various muscle related disorders. In addition, we review the diverse approaches used to inhibit the activity of MSTN, especially in silico approaches to the screening of natural compounds and the design of novel short peptides derived from proteins that typically interact with MSTN.

Myostatin Levels and the Risk of Myopenia and Rheumatoid Cachexia in Women with Rheumatoid Arthritis

Background

Myostatin is a regulator of muscle size. To date, there have been no published studies focusing on the relation between myostin levels and myopenia in rheumatoid arthritis (RA).

Objective

Evaluate the value of serum myostatin as a biomarker of cachexia and low skeletal muscle mass (LSMM) in RA patients, along with whether high serum myostatin is associated to these conditions after adjusting for potential confounders.

Methods

This cross-sectional study included 161 female RA patients and 72 female controls. In the RA group, we assessed several potential risk factors for LSMM and rheumatoid cachexia. Dual-energy X-ray absorptiometry was used to quantify the skeletal muscle mass index (SMMI) (considering LSMM ≤ 5.5 kg/m²) and the presence of rheumatoid cachexia (a fat-free mass index ≤ 10 percentile and fat mass index ≥ 25 percentile of the reference population). Serum myostatin concentrations were determined by ELISA. To identify a cut-off for high serum myostatin levels, we performed ROC curve analysis. Multivariable logistic regression analysis was used to identify the risk factors for LSMM and rheumatoid cachexia. The risk was expressed as odds ratios (ORs) and their 95% confidence intervals (95% CIs).

Results

Compared to the controls, the RA group had a higher proportion of LSMM and exhibited high serum myostatin levels (p < 0.001). ROC curve analysis showed that a myostatin level ≥ 17 ng/mL was the most efficient cut-off for identifying rheumatoid cachexia (sensitivity: 53%, specificity: 71%) and LSMM (sensitivity: 43%, specificity: 77%). In the multivariable logistic regression, RA with high myostatin levels (≥17 ng/mL) was found to increase the risk of cachexia (OR = 2.79, 95% CI: 1.24-6.29; p = 0.01) and LSMM (OR = 3.04, 95% CI: 1.17-7.89; p = 0.02).

Conclusions

High serum myostatin levels increase the risk of LSMM and rheumatoid cachexia. We propose that high myostatin levels are useful biomarkers for the identification of patients in risk of rheumatoid cachexia and myopenia.

Myostatin/Activin Receptor Ligands in Muscle and the Development Status of Attenuating Drugs

Muscle wasting disease indications are among the most debilitating and often deadly noncommunicable disease states. As a comorbidity, muscle wasting is associated with different neuromuscular diseases and myopathies, cancer, heart failure, chronic pulmonary and renal diseases, peripheral neuropathies, inflammatory disorders, and, of course, musculoskeletal injuries. Current treatment strategies are relatively ineffective and can at best only limit the rate of muscle degeneration. This includes nutritional supplementation and appetite stimulants as well as immunosuppressants capable of exacerbating muscle loss. Arguably, the most promising treatments in development attempt to disrupt myostatin and activin receptor signaling because these circulating factors are potent inhibitors of muscle growth and regulators of muscle progenitor cell differentiation. Indeed, several studies demonstrated the clinical potential of "inhibiting the inhibitors," increasing muscle cell protein synthesis, decreasing degradation, enhancing mitochondrial biogenesis, and preserving muscle function. Such changes can prevent muscle wasting in various disease animal models yet many drugs targeting this pathway failed during clinical trials, some from serious treatment-related adverse events and off-target interactions. More often, however, failures resulted from the inability to improve muscle function despite preserving muscle mass. Drugs still in development include antibodies and gene therapeutics, all with different targets and thus, safety, efficacy, and proposed use profiles. Each is unique in design and, if successful, could revolutionize the treatment of both acute and chronic muscle wasting. They could also be used in combination with other developing therapeutics for related muscle pathologies or even metabolic diseases.

Muscle-to-fat ratio identifies functional impairments and cardiometabolic risk and predicts outcomes: biomarkers of sarcopenic obesity

BACKGROUND

Sarcopenic obesity aims to capture the risk of functional decline and cardiometabolic diseases, but its operational definition and associated clinical outcomes remain unclear. Using data from the Longitudinal Aging Study of Taipei, this study explored the roles of the muscle-to-fat ratio (MFR) with different definitions and its associations with clinical characteristics, functional performance, cardiometabolic risk and outcomes.

METHODS

(1) Appendicular muscle mass divided by total body fat mass (aMFR), (2) total body muscle mass divided by total body fat mass (tMFR) and (3) relative appendicular skeletal muscle mass (RASM) were measured. Each measurement was categorized by the sex-specific lowest quintiles for all study participants. Clinical outcomes included all-cause mortality and fracture.

RESULTS

Data from 1060 community-dwelling older adults (mean age: 71.0 ± 4.8 years) were retrieved for the study. Overall, 196 (34.2% male participants) participants had low RASM, but none was sarcopenic. Compared with those with high aMFR, participants with low aMFR were older (72 ± 5.6 vs. 70.7 ± 4.6 years, P = 0.005); used more medications (2.9 ± 3.3 vs. 2.1 ± 2.5, P = 0.002); had a higher body fat percentage (38 ± 4.8% vs. 28 ± 6.4%, P < 0.001), RASM (6.7 ± 1.0 vs. 6.5 ± 1.1 kg/m² , P = 0.001), and cardiometabolic risk [fasting glucose: 105 ± 27.5 vs. 96.8 ± 18.7 mg/dL, P < 0.001; glycated haemoglobin (HbA1c): 6.0 ± 0.8 vs. 5.8 ± 0.6%, P < 0.001; triglyceride: 122.5 ± 56.9 vs. 108.6 ± 67.5 mg/dL, P < 0.001; high-density lipoprotein cholesterol (HDL-C): 56.2 ± 14.6 vs. 59.8 ± 16 mg/dL, P = 0.010]; and had worse functional performance [Montreal Cognitive Assessment (MoCA): 25.7 ± 4.2 vs. 26.4 ± 3.0, P = 0.143, handgrip strength: 24.7 ± 6.7 vs. 26.1 ± 7.9 kg, P = 0.047; gait speed: 1.8 ± 0.6 vs. 1.9 ± 0.6 m/s, P < 0.001]. Multivariate linear regression showed that age (β = 0.093, P = 0.001), body mass index (β = 0.151, P = 0.046), total percentage of body fat (β = 0.579, P < 0001) and RASM (β = 0.181, P = 0.016) were associated with low aMFR. Compared with those with high tMFR, participants with low tMFR were older (71.7 ± 5.5 vs. 70.8 ± 4.7 years, P = 0.075); used more medications (2.8 ± 3.3 vs. 2.1 ± 2.5, P = 0.006); had a higher body fat percentage (38.1 ± 4.7 vs. 28 ± 6.3%, P < 0.001), RASM (6.8 ± 1.0 vs. 6.5 ± 1.1 kg/m² , P < 0.001), and cardiometabolic risk (fasting glucose: 104.8 ± 27.6 vs. 96.9 ± 18.7 mg/dL, P < 0.001; HbA1c: 6.1 ± 0.9 vs. 5.8 ± 0.6%, P < 0.001; triglyceride: 121.4 ± 55.5 vs. 108.8 ± 67.8 mg/dL, P < 0.001; HDL-C: 56.4 ± 14.9 vs. 59.7 ± 15.9 mg/dL, P = 0.021); and had worse functional performance (MoCA: 25.6 ± 4.2 vs. 26.5 ± 3.0, P = 0.056; handgrip strength: 24.6 ± 6.7 vs. 26.2 ± 7.9 kg, P = 0.017; gait speed: 1.8 ± 0.6 vs. 1.9 ± 0.6 m/s, P < 0.001). Low tMFR was associated with body fat percentage (β = 0.766, P < 0.001), RASM (β = 0.476, P < 0.001) and Mini-Nutritional Assessment (β = -0.119, P < 0.001). Gait speed, MoCA score, fasting glucose, HbA1c and tMFR were significantly associated with adverse outcomes, and the effects of aMFR were marginal (P = 0.074).

CONCLUSIONS

Older adults identified with low MFR had unfavourable body composition, poor functional performance, high cardiometabolic risk and a high risk for the clinical outcome.

Multifactorial Mechanism of Sarcopenia and Sarcopenic Obesity. Role of Physical Exercise, Microbiota and Myokines

Obesity and ageing place a tremendous strain on the global healthcare system. Age-related sarcopenia is characterized by decreased muscular strength, decreased muscle quantity, quality, and decreased functional performance. Sarcopenic obesity (SO) is a condition that combines sarcopenia and obesity and has a substantial influence on the older adults’ health. Because of the complicated pathophysiology, there are disagreements and challenges in identifying and diagnosing SO. Recently, it has become clear that dysbiosis may play a role in the onset and progression of sarcopenia and SO. Skeletal muscle secretes myokines during contraction, which play an important role in controlling muscle growth, function, and metabolic balance. Myokine dysfunction can cause and aggravate obesity, sarcopenia, and SO. The only ways to prevent and slow the progression of sarcopenia, particularly sarcopenic obesity, are physical activity and correct nutritional support. While exercise cannot completely prevent sarcopenia and age-related loss in muscular function, it can certainly delay development and slow down the rate of sarcopenia. The purpose of this review was to discuss potential pathways to muscle deterioration in obese individuals. We also want to present the current understanding of the role of various factors, including microbiota and myokines, in the process of sarcopenia and SO.

Serum Myostatin and Follistatin Levels in Patients With Dermatomyositis and Polymyositis

BACKGROUND

Myostatin is a protein in the TGF-β family that negatively regulates muscle mass, and follistatin is a myostatin antagonist.

OBJECTIVE

The aim of this study was to measure serum levels of myostatin and follistatin in idiopathic inflammatory myopathy patients and correlate these levels with muscle strength, fatigue, functional capacity, damage, and serum levels of muscle enzymes.

METHODS

This was a multicenter cross-sectional study including 50 patients (34 dermatomyositis and 16 polymyositis [PM]) and 52 healthy individuals (control group [CG]). The disease status was evaluated according to the International Myositis Assessment & Clinical Studies. Fatigue was rated according to the Fatigue Severity Scale, and body composition was measured using dual-energy x-ray emission densitometry. Myostatin and follistatin were measured using enzyme-linked immunosorbent assays.

RESULTS

Mean age was 50.9 ± 14.0 years, and mean disease duration was 89.2 ± 80.9 months. There were no differences in levels of myostatin (14.15 ± 9.65 vs. 10.97 ± 6.77 ng/mL; p = 0.131) or follistatin (0.53 ± 0.71 vs. 0.49 ± 0.60 ng/mL; p = 0.968) between patients and the CG. However, myostatin levels were higher in PM than CG (16.9 ± 12.1 vs. 11.0 ± 6.8 ng/mL; p = 0.036). There was no difference in serum myostatin among patients with and without low lean mass. Patients not treated with corticosteroids had higher serum levels of myostatin than the CG. There was a weak negative correlation between follistatin and Manual Muscle Testing and a Subset of Eight Muscles and a weak positive correlation between follistatin and Healthy Assessment Questionnaire.

CONCLUSIONS

Serum levels of myostatin and follistatin did not differ between dermatomyositis and PM patients and control subjects. The assessment of serum levels of myostatin and follistatin in idiopathic inflammatory myopathy patients seems not to be helpful in clinical practice.

Muscle-derived factors influencing bone metabolism

A significant amount of attention has been brought to the endocrine-like function of skeletal muscle on various tissues, particularly with bone. Several lines of investigation indicate that the physiology of both bone and muscle systems may be regulated by a given stimulus, such as exercise, aging, and inactivity. Moreover, emerging evidence indicates that bone is heavily influenced by soluble factors derived from skeletal muscle (i.e., muscle-to-bone communication). The purpose of this review is to discuss the regulation of bone remodeling (formation and/or resorption) through skeletal muscle-derived cytokines (hereafter myokines) including the anti-inflammatory cytokine METRNL and pro-inflammatory cytokines (e.g., TNF-α, IL-6, FGF-2 and others). Our goal is to highlight possible therapeutic opportunities to improve muscle and bone health in aging.

Changes in Serum Myostatin Levels in Alcoholic Hepatitis Correlate with Improvement in MELD

BACKGROUND

Alcoholic hepatitis (AH) is a serious clinical syndrome often associated with muscle wasting. Myostatin, a member of the transforming growth factor-β superfamily, has been studied in diseases with muscle wasting; however, the role of myostatin in AH is unknown.

AIMS

To investigate the association between myostatin, clinical variables, and outcomes in AH.

METHODS

We analyzed data for cases of AH and controls of heavy drinkers (HD) in TREAT001 (NCT02172898) with serum myostatin levels (AH: n = 131, HD: n = 124). We compared characteristics between the two groups at baseline, 30, and 90 days and explored correlations between myostatin and clinical variables. We then modeled the relationship of myostatin to other variables, including mortality.

RESULTS

Baseline median myostatin was lower in AH compared to HD (males: 1.58 vs 3.06 ng/ml, p < 0.001; females: 0.84 vs 2.01 ng/ml, p < 0.001). In multivariable linear regression, bilirubin, WBC, and platelet count remained negatively correlated with myostatin in AH. AH females who died at 90 days had significantly lower myostatin, but in a multivariable logistic model with MELD and myostatin, only MELD remained significantly associated with 90-day mortality. During 1-year follow-up, AH cases (n = 30) demonstrated an increase in myostatin (mean, 1.73 ng/ml) which correlated with decreasing MELD scores (ρ = - 0.42, p = 0.01).

CONCLUSIONS

Myostatin levels are significantly lower in AH compared to HD and are negatively correlated with total bilirubin, WBC, and platelet count. Myostatin increased as patients experienced decreases in MELD. Overall, myostatin demonstrated a dynamic relationship with AH outcomes and future studies are needed to understand the prognostic role of myostatin in AH.

Serum Amino Acids Patterns and 4-Year Sarcopenia Risk in Community-Dwelling Chinese Older Adults

INTRODUCTION

Dietary protein intake and serum amino acids (AAs) are factors controlling the rate of muscle protein synthesis and catabolism. This study examined the association between serum AAs patterns and incident sarcopenia in community-dwelling older adults.

METHODS

Chinese older adults in Hong Kong aged ≥65 years attended a health check at baseline and 4-year follow-up. At baseline, fasting blood was collected to measure 17 serum AAs. Serum AAs patterns were identified using principal component analysis. Dietary protein intake was assessed using a validated food frequency questionnaire. A composite score was computed by summing the principal component score and sex-standardized protein intake. Six composite scores representing each AAs pattern were available for each participant. Sarcopenia was defined using the updated version of the Asian Working Group for Sarcopenia. Crude and adjusted multiple logistic regressions were performed to examine the associations between each of the 6 composite scores and sarcopenia over 4 years. Results are presented as odds ratio (OR) and 95% confidence interval (CI). To address multiple testing, a Bonferroni correction was applied using a corrected significance level of p < 0.008 (α 0.05/6 patterns).

RESULTS

Data of 2,610 participants (mean age 71.6 years, 45.4% men) were available. In men, serum AAs patterns characterized by high branched-chain AAs (BCAAs) (OR 0.77, 95% CI 0.69-0.87, p < 0.001) and tyrosine, tryptophan, and phenylalanine (OR 0.79, 95% CI 0.71-0.89, p < 0.001) were significantly associated with a lower risk of sarcopenia over 4-year follow-up. After adjusting for confounders, the associations were no longer significant. In women, serum AAs patterns characterized by glutamine, glutamic acid, and methionine (OR 1.28, 95% CI 1.11-1.47, p = 0.001) and arginine, taurine, and serine (OR 1.20, 95% CI 1.06-1.35, p = 0.003) were associated with a higher risk of sarcopenia. After adjusting for confounders, serum AAs pattern characterized by high BCAAs (adjusted OR 1.52, 95% CI 1.25-1.86, p < 0.001) and arginine, taurine, and serine (adjusted OR 1.30, 95% CI 1.09-1.56, p = 0.004) were significantly associated with a higher risk of sarcopenia. No association between other AAs patterns with incident sarcopenia was found.

CONCLUSIONS

In community-dwelling Chinese older adults, serum AAs patterns characterized by high BCAAs and nonessential AAs (arginine, taurine, and serine) were associated with a higher risk of sarcopenia in women. Findings may allow identifying new targets for interventions.

Myostatin/Appendicular Skeletal Muscle Mass (ASM) Ratio, Not Myostatin, Is Associated with Low Handgrip Strength in Community-Dwelling Older Women

Background/Aims: Elevated levels of serum myostatin have been proposed as a biomarker for sarcopenia. Recent studies have shown that elevated level of serum myostatin was associated with physical fitness and performance. This study aimed to examine the significance of myostatin in the association between muscle mass and physical performance in the elderly. Methods: This cross-sectional study is based on the Korean Frailty and Aging Cohort study involving 1053 people aged 70 years or over. Anthropometric, physical performance, and laboratory data were collected. Results: The mean age of the participants was 75.8 years, and 50.7% of them were female. Serum myostatin levels in men (3.7 ± 1.2 vs. 3.2 ± 1.1 ng/mL, p < 0.001) were higher compared with that in women. Serum myostatin level was associated with appendicular skeletal muscle mass (ASM) index and eGFR by cystatin C. Serum myostatin/ASM ratio was associated with handgrip strength in women. Conclusion: Higher serum myostatin levels were related with higher muscle mass and better physical performances in the elderly. Serum myostatin/ASM ratio may be a predictor for physical performance rather than myostatin.

A highly prevalent SINE mutation in the myostatin (MSTN) gene promoter is associated with low circulating myostatin concentration in Thoroughbred racehorses

Horse racing is a popular and financially important industry worldwide and researchers and horse owners are interested in genetic and training influences that maximise athletic performance. An association has been found between the presence of a short interspersed nuclear element (SINE) mutation in the myostatin (MSTN) gene promoter and optimal race distance in Thoroughbred horses. There is previous laboratory evidence that this mutation reduces MSTN expression in a cell culture model and influences skeletal muscle fibre type proportions in horses. Manipulating MSTN expression has been proposed for illicit gene doping in human and equine athletes and already, researchers have generated homozygous and heterozygous MSTN-null horse embryos following CRISPR/Cas9 editing at the equine MSTN locus and nuclear transfer, aiming artificially to enhance performance. To date however, the role of the naturally-occurring equine MSTN SINE mutation in vivo has remained unclear; here we hypothesised that it reduces, but does not ablate circulating myostatin expression. Following validation of an ELISA for detection of myostatin in equine serum and using residual whole blood and serum samples from 176 Thoroughbred racehorses under identical management, horses were genotyped for the SINE mutation by PCR and their serum myostatin concentrations measured. In our population, the proportions of SINE homozygotes, heterozygotes and normal horses were 27%, 46% and 27% respectively. Results indicated that horses that are homozygous for the SINE mutation have detectable, but significantly lower (p < 0.0001) serum myostatin concentrations (226.8 pg/ml; 69.3–895.4 pg/ml; median; minimum–maximum) than heterozygous (766 pg/ml; 64.6–1182 pg/ml) and normal horses (1099 pg/ml; 187.8–1743 pg/ml). Heterozygotes have significantly lower (p < 0.0001) myostatin concentrations than normal horses. Variation in serum myostatin concentrations across horses was not influenced by age or sex. This is the first study to reveal the direct functional effect of a highly prevalent mutation in the equine MSTN gene associated with exercise performance. Determining the reason for variation in expression of myostatin within SINE-genotyped groups might identify additional performance-associated environmental or genetic influences in Thoroughbreds. Understanding the mechanism by which altered myostatin expression influences skeletal muscle fibre type remains to be determined.

The prevalence of sarcopenia and relationships between dietary intake and muscle mass in head and neck cancer patients undergoing radiotherapy: A longitudinal study

PURPOSE

Our study aims to investigate dietary intake characteristics and their association with skeletal muscle mass in head and neck cancer patients treated with radiotherapy.

METHODS

From March 2017 to August 2018, patients with head and neck cancer who received radiotherapy at our affiliated hospital were enrolled. Dietary intake was assessed through 24-hr dietary recall and skeletal muscle mass was evaluated by bioelectrical impedance analysis at three-time points. Appendicular skeletal muscle mass was adjusted for height squared defined sarcopenia and correlated with dietary intake by generalized estimating equations (GEE).

RESULTS

This study sample comprised 287 patients [median age: 54 years; 187 (65.2%) men]. Median dietary intake at post-treatment was 14.95 kcal/kg/day energy and 0.63 g/kg/day protein. Skeletal muscle mass decreased significantly in all patients. The prevalence of sarcopenia increased from 24.4% before treatment to 46.7% at the end of treatment. Exploratory univariate GEE analysis revealed that radiotherapy time-point, male-gender, age ≥60 and decreased dietary energy intake significantly impacted on muscle loss represented by the appendicular skeletal muscle index. After controlling covariates, dietary energy intake was only positively associated with muscle loss in women (P = 0.013, 95% CI = 0.003-0.027) but not in men (P = 0.788, 95% CI = -0.007-0.009).

CONCLUSION

While the loss in skeletal muscle is more prevalent in men receiving radiotherapy, the effects of dietary energy intake were only associated with women. A prospective randomized clinical trial is required to identify the appropriate amount of dietary energy supplement by gender in cancer patients treated with radiotherapy.

Antimyostatin Treatment in Health and Disease: The Story of Great Expectations and Limited Success

In the past 20 years, myostatin, a negative regulator of muscle mass, has attracted attention as a potential therapeutic target in muscular dystrophies and other conditions. Preclinical studies have shown potential for increasing muscular mass and ameliorating the pathological features of dystrophic muscle by the inhibition of myostatin in various ways. However, hardly any clinical trials have proven to translate the promising results from the animal models into patient populations. We present the background for myostatin regulation, clinical and preclinical results and discuss why translation from animal models to patients is difficult. Based on this, we put the clinical relevance of future antimyostatin treatment into perspective.

Association of serum adiponectin and myostatin levels with skeletal muscle in patients with obesity: A cross-sectional study

Background

Adiponectin has been reported to be associated with lower skeletal muscle mass and skeletal strength and may be involved in skeletal muscle regulation along with myostatin. This study aims to evaluate the association between serum adiponectin and myostatin levels and identify independent factors using body composition and metabolic parameters in patients with obesity.

Methods

Overall, 148 patients (age, 45.9 ± 14.3 years, body mass index, 37.2 ± 8.0 kg/m²) who initially visited the outpatient clinic of obesity between November 2013 and November 2019 were included. Body composition was measured using InBody 720 and dual energy X-ray absorptiometry. In addition, muscle strength, vascular function, and metabolic parameters were measured. Serum levels of adiponectin, leptin, myostatin, and irisin were measured from blood samples.

Results

The serum adiponectin level was 2.9 μg/mL (1.7–4.1 μg/mL), and the serum myostatin level was 2398.4 pg/mL (1,777.1–2952.5 pg/mL). The stepwise regression analysis revealed less leg strength, homeostasis model assessment of insulin resistance, and C-reactive protein as an independent predictor of serum adiponectin levels based on the significance of the univariate analysis (R² = 0.190, P < 0.001). A high appendicular lean mass/body weight, reactive hyperemia index, and irisin were independent factors for serum myostatin levels (R² = 0.260, P < 0.001)

Conclusion

The serum adiponectin level was associated with less muscle strength. Although serum myostatin was associated with a high appendicular lean mass, it is possible that myostatin was regulated by the percentage of body weight from appendicular lean mass.

Muscle mass and plasma myostatin after exercise training: a substudy of Renal Exercise (RENEXC)-a randomized controlled trial

BACKGROUND

Sarcopenia increases as renal function declines and is associated with higher morbidity and mortality. Myostatin is a negative regulator of muscle growth. Its expression in response to exercise is unclear. In this prespecified substudy of the Renal Exercise (RENEXC) trial, we investigated the effects of 12 months of exercise training on sarcopenia, muscle mass and plasma myostatin and the relationships between physical performance, muscle mass and plasma myostatin.

METHODS

A total of 151 non-dialysis-dependent patients (average measured glomerular filtration rate 23 ± 8 mL/min/1.73 m2), irrespective of age or comorbidity, were randomly assigned to either strength or balance in combination with endurance training. Body composition was measured with dual-energy X-ray absorptiometry. Plasma myostatin was analysed using enzyme-linked immunosorbent assay kits.

RESULTS

After 12 months, the prevalence of sarcopenia was unchanged, leg and whole-body lean mass increased significantly in the balance group and was unchanged in the strength group. Whole fat mass decreased significantly in both groups. There were no significant between-group differences in sarcopenia or body composition. Plasma myostatin levels increased significantly in both groups, with a significant difference in favour of the strength group. Plasma myostatin was significantly positively related to muscle mass and physical performance at baseline, but these relationships were attenuated after 12 months.

CONCLUSIONS

Exercise training seems to be effective in preventing sarcopenia and maintaining muscle mass in non-dialysis-dependent patients with chronic kidney disease (CKD). However, the role of plasma myostatin on muscle mass and physical performance in patients with CKD warrants further study.

The relationship between circulating vitamin D3 and subclinical atherosclerosis in an elderly Asian population

The current evidence regarding the association between vitamin D deficiency and cardiovascular diseases/metabolic disorders is contradictory and inconclusive. In this large-scale observational study, we investigated the relationship between the serum 25-hydroxy vitamin D3 [25(OH)D] concentration and subclinical atherosclerosis in an elderly Asian population. In the I-Lan longitudinal study (ILAS), 1798 elderly, aged 50 and older, were enrolled. For each subject, serum 25-hydroxy vitamin D3 [25(OH)D] concentration and demographic data were recorded. The participants were divided into two groups according to their serum 25(OH)D level (sufficient, > 20 ng/mL and deficient, ≤ 20 ng/mL). Carotid intima-media thickness (cIMT) was measured at bilateral common carotid arteries. Subclinical atherosclerosis was defined as a mean cIMT > 0.81 mm. The mean subject age was 64 ± 9 years old, and 604 (33.6%) were identified as having serum 25(OH)D level ≤ 20 ng/mL. Subjects with serum 25(OH)D level ≤ 20 ng/mL were younger, more likely to be female and smoker, and had a higher incidence of hypertension, dyslipidemia, and metabolic syndrome, compared to those with serum 25(OH)D level > 20 ng/mL. Additionally, patients with serum 25(OH)D level ≤ 20 ng/mL were associated with a lower risk of subclinical atherosclerosis (crude OR: 0.63, 95% CI 0.50–0.81, p < 0.001), according to univariate analysis. However, after adjusting for gender and age, serum 25(OH)D level ≤ 20 ng/mL was not a significant risk factor for subclinical atherosclerosis. Serum 25(OH)D level ≤ 20 ng/mL was not an independent risk factor for subclinical atherosclerosis in this large elderly Asian population. Association observed in the univariate analysis may be confounded by gender or comorbidities.

Exercise-Induced Myokines can Explain the Importance of Physical Activity in the Elderly: An Overview

Physical activity has been found to aid the maintenance of health in the elderly. Exercise-induced skeletal muscle contractions lead to the production and secretion of many small proteins and proteoglycan peptides called myokines. Thus, studies on myokines are necessary for ensuring the maintenance of skeletal muscle health in the elderly. This review summarizes 13 myokines regulated by physical activity that are affected by aging and aims to understand their potential roles in metabolic diseases. We categorized myokines into two groups based on regulation by aerobic and anaerobic exercise. With aging, the secretion of apelin, β-aminoisobutyric acid (BAIBA), bone morphogenetic protein 7 (BMP-7), decorin, insulin-like growth factor 1 (IGF-1), interleukin-15 (IL-15), irisin, stromal cell-derived factor 1 (SDF-1), sestrin, secreted protein acidic rich in cysteine (SPARC), and vascular endothelial growth factor A (VEGF-A) decreased, while that of IL-6 and myostatin increased. Aerobic exercise upregulates apelin, BAIBA, IL-15, IL-6, irisin, SDF-1, sestrin, SPARC, and VEGF-A expression, while anaerobic exercise upregulates BMP-7, decorin, IGF-1, IL-15, IL-6, irisin, and VEGF-A expression. Myostatin is downregulated by both aerobic and anaerobic exercise. This review provides a rationale for developing exercise programs or interventions that maintain a balance between aerobic and anaerobic exercise in the elderly.

Subtypes of physical frailty and their long-term outcomes: a longitudinal cohort study

BACKGROUND

Components of physical frailty cluster into subtypes, but it remains unknown how these might be associated with age-related functional declines and multimorbidities. This study aims to investigated associations of physical frailty subtypes with functional declines and multimorbidity in a 10 year longitudinal cohort survey.

METHODS

Complementary longitudinal cohort study used group-based multitrajectory modelling to verify whether frailty subtypes discovered in Taiwan are presented in another aging cohort, then investigated associations of these subtypes with cognitive decline and multimorbidity. Participants aged ≥50 years were recruited from the third to sixth waves (May 2002 to July 2010) of the National Institute for Longevity Sciences-Longitudinal Study of Aging, in Japan. People with incomplete data, pre-frail/frail status before their index wave, and those with incomplete data or who died during follow-up, were excluded. Group-based trajectory analysis denoted five established physical frailty criteria as time-varying binary variables in each wave during follow-up. Incident frailty was classified as mobility subtype (weakness/slowness), non-mobility subtype (weight loss/exhaustion), or low physical activity subtype. General linear modelling investigated associations of these frailty subtypes with activities of daily living, digit symbol substitution test (DSST) and Charlson Comorbidity Index (CCI) at 2 year follow-up.

RESULTS

We identified four longitudinal trajectories of physical frailty, which corroborated the distinct subtypes we discovered previously. Among 940 eligible participants, 38.0% were robust, 18.4% had mobility subtype frailty, 20.7% non-mobility subtype, and 20.1% low physical activity subtype. People with mobility subtype frailty were older than those with other frailty subtypes or robust status and had higher prevalence of hypertension, diabetes, and heart failure. In the multivariable-adjusted general linear models, mobility-subtype frailty was associated with a significantly lower DSST score (point estimate -2.28, P = 0.03) and higher CCI (point estimate 0.82, P < 0.01) than the other groups.

CONCLUSIONS

Mobility-subtype frailty was associated with functional declines and progression of multimorbidity; the long-term effects of physical frailty subtypes deserve further investigation.

The role of activin: the other side of chronic kidney disease-mineral bone disorder?

Chronic kidney disease-mineral bone disorder (CKD-MBD) plays a pivotal role in the excess of cardiovascular morbidity and mortality associated with CKD. There is now a growing awareness that pathways involved in CKD-MBD, like canonical Wnt signalling, are activated from the earliest stages of CKD, playing a role in the development of adynamic bone disease with unknown consequences on vasculature. These changes occur before the classic changes in mineral metabolism: secondary hyperparathyroidism, calcitriol deficiency and hyperphosphataemia. Furthermore, vascular calcification is frequently associated and evolves with decreased bone mineral density and deranged bone turnover, while bone and arterial mineralization share common pathways. Therefore, results of clinical trials focused on mineral bone disorder, aimed at preserving bone and cardiovascular health, are considered unsatisfactory. In order to identify more effective therapeutic strategies, it is necessary to clarify the pathways modulating the cross-talk between bone and vasculature and identify new mediators involved in the pathogenesis of CKD-MBD. Much attention has been paid recently to the role of the transforming growth factor-beta superfamily members in renal disease, and in particular of activin A (ActA). Preclinical studies demonstrate an upgrade of ActA signalling in kidney, skeleton, vasculature and heart during CKD. This supports the idea that an endocrine factor produced in the kidney during renal disease, in addition to promoting the progression of kidney damage, deranges other organs' homoeostasis and participates in CKD-MBD. In this review, we analyse the contribution of ActA to kidney fibrosis and inflammation as well as its role in the development of CKD-MBD.

Comparisons of Muscle Quality and Muscle Growth Factor Between Sarcopenic and Non-Sarcopenic Older Women

Sarcopenia, an age-related disease, is one of the important health problems in the elderly and the prevalence of sarcopenia is rapidly increased among the Korean population. This study examined the muscle quality and muscle growth factors of elderly women to identify the potential diagnostic tool for sarcopenia. One hundred and thirty-six elderly women, aged over 65 years old, initially enrolled, but only 59 participants who met the criteria (sarcopenic group, n = 27; non-sarcopenic group, n = 32) completed the study. Muscle quality assessment included thigh cross-sectional computed tomography scan and maximal isometric muscle strength. Muscle growth factors such as GDF-15, myostatin, activin A, and follistatin were analyzed, and a battery of Senior Fitness Test was used to examine functional fitness. The statistical significance level was set at 0.05. Elderly women with sarcopenia had a lower thigh muscle volume (-20.1%), and a higher thigh intermuscular adipose tissue (15.8%) than those of the non-sarcopenic group (p < 0.05). However, no significant differences in muscle growth factors were observed between the groups. Muscle quality variables including maximal voluntary isometric contraction (OR: 0.968, p < 0.001), relative maximal voluntary isometric contraction (OR: 0.989, p < 0.05), thigh muscle volume (OR: 0.836, p < 0.001), and thigh intermuscular adipose tissue (OR: 1.138, p < 0.05) were associated with a risk of sarcopenia. Our findings suggest that the sarcopenic group exhibits a poor thigh muscle quality in comparison with the non-sarcopenic group. Muscle quality assessment can be utilized for sarcopenia identification, but our study remains inconclusive for the causality of muscle growth factors in sarcopenia.

Associations of body composition with incident dementia in older adults: Cardiovascular Health Study-Cognition Study

INTRODUCTION

A body of literature reported associations between late-life general adiposity measures (eg, body mass index) and dementia. Little is known about the association of late-life body composition with dementia risk.

METHODS

We determined this association among cognitively normal participants from the Cardiovascular Health Study- Cognition Study. Body composition was assessed by dual-energy x-ray absorptiometry in 1994-1995. Dementia was ascertained at annual follow-up from 1998-1999 to 2013. Associations of body composition with incident dementia were assessed by the Fine-Gray model.

RESULT

Among 344 participants (mean age 78, 62.2% women), body composition was significantly different between men and women, despite similar body mass indexes (BMIs). Increased dementia risk was significantly associated with lower lean mass in men and marginally with low appendicular lean mass in women.

DISCUSSION

Decreased lean mass was an indicator of increased dementia risk in older adults. Studies should test whether preventing lean mass loss in older adults reduces dementia risk.

Myostatin as a Biomarker of Muscle Wasting and other Pathologies-State of the Art and Knowledge Gaps

Sarcopenia is a geriatric syndrome with a significant impact on older patients’ quality of life, morbidity and mortality. Despite the new available criteria, its early diagnosis remains difficult, highlighting the necessity of looking for a valid muscle wasting biomarker. Myostatin, a muscle mass negative regulator, is one of the potential candidates. The aim of this work is to point out various factors affecting the potential of myostatin as a biomarker of muscle wasting. Based on the literature review, we can say that recent studies produced conflicting results and revealed a number of potential confounding factors influencing their use in sarcopenia diagnosing. These factors include physiological variables (such as age, sex and physical activity) as well as a variety of disorders (including heart failure, metabolic syndrome, kidney failure and inflammatory diseases) and differences in laboratory measurement methodology. Our conclusion is that although myostatin alone might not prove to be a feasible biomarker, it could become an important part of a recently proposed panel of muscle wasting biomarkers. However, a thorough understanding of the interrelationship of these markers, as well as establishing a valid measurement methodology for myostatin and revising current research data in the light of new criteria of sarcopenia, is needed.

Sarcopenia Is Associated With Development of Acute-on-Chronic Liver Failure in Decompensated Liver Cirrhosis Receiving Transjugular Intrahepatic Portosystemic Shunt

Muscle mass has been shown to be a prognostic marker in patients with liver cirrhosis. Transversal psoas muscle thickness normalized by height (TPMT/height) obtained by routine computed tomography is a simple surrogate parameter for sarcopenia. TPMT/height, however, is not sex specific, which might play a role in risk stratification. Its association with acute-on-chronic liver failure (ACLF) has not been established yet. ACLF is associated with systemic inflammatory dysregulation. This study aimed at evaluating the role of sarcopenia in ACLF development of patients with decompensated cirrhosis receiving transjugular intrahepatic portosystemic shunt (TIPS) using sex-specific TPMT/height.

Sarcopenic obesity: Myokines as potential diagnostic biomarkers and therapeutic targets?

Sarcopenic obesity (SO) is a condition characterized by the occurrence of both sarcopenia and obesity and imposes a heavy burden on the health of the elderly. Controversies and challenges regarding the definition, diagnosis and treatment of SO still remain because of its complex pathogenesis and limitations. Over the past few decades, numerous studies have revealed that myokines secreted from skeletal muscle play significant roles in the regulation of muscle mass and function as well as metabolic homeostasis. Abnormalities in myokines may trigger and promote the pathogenesis underlying age-related and metabolic diseases, including obesity, sarcopenia, type 2 diabetes (T2D), and SO. This review mainly focuses on the role of myokines as potential biomarkers for the early diagnosis and therapeutic targets in SO.

Myokines and adipokines in sarcopenia: understanding cross-talk between skeletal muscle and adipose tissue and the role of exercise

Detrimental age-associated changes in skeletal muscle and adipose tissue increase the risk of sarcopenia. Age-related changes in myokines, such as myostatin and irisin, as well as adipokines, such as leptin and adiponectin, contribute to cross-talk between muscle and adipose tissue. These age-related changes in myokines and adipokines have important implications for sarcopenia, however, recent literature highlights discrepancies in these relationships. Exercise may alter serum profiles and muscle receptor expression of these factors, but future work is needed to determine whether these changes in myokines and adipokines relate to improvements in muscle mass and function. Here, we describe myokine-mediated and adipokine-mediated interactions between muscle and adipose tissue, and discuss the fundamental importance of these cytokines to understanding the development of sarcopenia.

The association of the serum levels of myostatin, follistatin, and interleukin-6 with sarcopenia, and their impacts on survival in patients with hepatocellular carcinoma

Background/Aims

The role of serum myokine levels in sarcopenia and the outcome of hepatocellular carcinoma (HCC) patients are not clear. This study investigated the serum levels of myostatin, follistatin, and interleukin-6 (IL-6) in HCC patients and their association with sarcopenia and survival.

Methods

Using prospectively collected pretreatment samples from 238 HCC patients in a hospital from 2012 to 2015, the serum levels of 3 myokines were determined and compared to 50 samples from age and sex-matched healthy controls. Sarcopenia was evaluated using the psoas muscle index (PMI) measured at the third lumbar level in the computed tomography, and clinical data were collected until 2017.

Results

The median levels of the 3 myokines for the male and female HCC patients were as follow: myostatin (3,979.3 and 2,976.3 pg/mL), follistatin (2,118.5 and 2,174.6 pg/mL), and IL-6 (2.5 and 2.7 pg/mL), respectively. Those in the HCC patients were all significantly higher than in the healthy controls. In the HCC patient, the median PMI was 4.43 (males) and 2.17 cm²/m² (females) with a sarcopenic prevalence of 56.4%. The serum levels of myostatin, IL-6 and follistatin in the HCC patients showed a positive, negative, and no correlation with PMI, respectively. The serum follistatin level was an independent factor for poor survival in HCC patients.

Conclusions

The serum levels of myostatin, follistatin, and IL-6 and their correlation with sarcopenia and survival were presented in HCC patients for the first time. The role of the serum follistatin level as a poor prognostic biomarker warrants further study.

Myostatin A55T Genotype is Associated with Strength Recovery Following Exercise-Induced Muscle Damage

Myostatin A55T genotype is one of the candidates showing inter-individual variation in skeletal muscle phenotypes. The aim of this study was to investigate the effect of the myostatin A55T genotype on markers of muscle damage after eccentric exercise. Forty-eight young, healthy male college students (age = 24.8 ± 2.2 years, height = 176.7 ± 5.3 cm, weight = 73.7 ± 8.3 kg) were enrolled in this study, and muscle damage was induced through 50 reps of maximal eccentric muscle contraction. As markers of muscle damage, maximal isometric strength (MIS), muscle soreness, creatine kinase (CK), and aspartate transaminase (AST) were measured. Myostatin A55T genotypes were classified into homozygous myostatin A55T allele (AA, n = 34, 72%), heterozygous myostatin A55T allele (AT, n = 13, 26%), and homozygous mutant carriers (TT, n = 1, 2%). After eccentric exercise, the subjects with heterozygous for AT showed markedly quicker MIS recovery compared to the AA group (p = 0.042). However, there were no significant variations in muscle soreness (p = 0.379), CK (p = 0.955), and AST (p = 0.706) among the groups. These results suggest that AT in myostatin A55T genotype may be associated with quicker strength recovery following exercise-induced muscle damage.

Implications of maraviroc and/or rapamycin in a mouse model of fragility

Background: As age increases, the risk of developing fragility also increases. Improving the knowledge of frailty could contribute to maintaining the functional ability of elderly people. Interleukin (IL)-10 homozygous knockout mice (IL-10^tm/tm [IL10KO]) constitute an excellent tool for the study of frailty. Because patients with frailty demonstrate an overexpression of CCR5, rapamycin (RAPA) and/or maraviroc (MVC), two molecules able to decrease CCR5 expression, were evaluated.

Results: Muscle myostatin was reduced in all the therapeutic groups but the MVC group (p <0.001 for RAPA and MVC-RAPA) and in serum samples (p <0.01 for all the groups). Serum CK levels were also significantly lower in MVC and RAPA groups (p <0.01 in both cases). Lower AST levels were observed in all the therapeutic groups (p <0.05 for all of them). The apoptotic effector caspase-3 was significantly lower in MVC and RAPA groups (p<0.05 in both cases). Combined treatment with MVC-RAPA showed a synergistic increase in p-AKT, p-mTOR and SIRT1 levels.

Conclusions: MVC and RAPA show a protective role in some factors involved in frailty. More studies are needed to prove their clinical applications.

Material and methods: Eighty male homozygous IL10KOs were randomly assigned to one of 4 groups (n= 20): i) IL10KO group (IL10KO); ii) IL10KO receiving MVC in drinking water (MVC group), iii) IL10KO receiving RAPA in drinking water (RAPA group), and finally, iv) MVC-RAPA group that received MVC and RAPA in drinking water. Blood and muscle samples were analysed. Survival analysis, frailty index calculation, and functional assessment were also performed.