Omega-3 polyunsaturated fatty acids in sarcopenia management: A network meta-analysis of randomized controlled trials

The impact of lifestyle factors across the life course on sarcopenia and physical frailty

PURPOSE OF REVIEW

Muscle health helps maintain locomotor capacity, a key component of intrinsic capacity, which is required for healthy ageing. Sarcopenia is characterized by the age-related decline in muscle mass and strength leading to impaired physical performance, and has been described as a biological substrate of physical frailty. Both sarcopenia and physical frailty share phenotypic features of weakness and slowness, lead to common adverse outcomes, and have potential for reversal through early identification and intervention. The purpose of this review is to present recent evidence for the impact of lifestyle interventions across the life course on sarcopenia and physical frailty.

RECENT FINDINGS

Resistance exercise alone or combined with balance and aerobic training as part of a multicomponent exercise program and high-quality diets incorporating adequate protein remain the mainstay of treatment for sarcopenia and physical frailty. Reducing sedentary time and increasing physical activity, adherence to Mediterranean diet, increasing vegetable and caffeinated beverage intake, cardiovascular risk factor modification, improving sleep hygiene and depressive symptoms may also contribute to slowing down age-related decline in muscle health.

SUMMARY

Lifestyle interventions such as physical activity, diet, sleep and mental health are effective against sarcopenia and physical frailty. Targeting lifestyle modifications in early to midlife may retard further decline in locomotor capacity and optimize intrinsic capacity of older persons, reducing the risk of sarcopenia, physical frailty and their attendant negative health outcomes.

The combined effects of omega-3 polyunsaturated fatty acid supplementation and exercise training on body composition and cardiometabolic health in adults: A systematic review and meta-analysis

INTRODUCTION

We performed a systematic review and meta-analysis to investigate the effects of combining omega-3 polyunsaturated fatty acids (n-3 PUFAs) supplementation with exercise training, as compared to exercise training alone, on body composition measures including body weight, body mass index (BMI), fat mass, body fat percentage, and lean body mass. Additionally, we determined the effects on cardiometabolic health outcomes including lipid profiles, blood pressure, glycemic markers, and inflammatory markers.

METHOD

Three primary electronic databases including PubMed, Web of Science, and Scopus were searched from inception to April 5th, 2023 to identify original articles comparing n-3 PUFA supplementation plus exercise training versus exercise training alone, that investigated at least one of the following outcomes: fat mass, body fat percentage, lean body mass, triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), systolic (SBP) and diastolic (DBP) blood pressures, fasting glucose and insulin, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Standardized mean differences (SMD) or weighted mean differences (WMD), and 95 % confidence intervals (CIs) were calculated using random-effects models.

RESULTS

A total of 21 studies involving 673 participants with BMIs ranging from 24 to 37 kg.m2 and ages ranging from 30 to 70 years were included in the meta-analysis. Overall, the results indicated that as compared with exercise training alone, adding omega-3 supplementation to exercise training decreased fat mass [WMD: -1.05 kg (95 % CI: -1.88 to -0.22), p = 0.01], TG [WMD: -0.10 mmol/L (95 % CI: -0.19 to -0.02)], SBP [WMD: -4.09 mmHg (95 % CI: -7.79 to -2.16), p = 0.03], DBP [WMD: -4.26 mmHg (95 % CI: -6.46 to -2.07), p = 0.001], and TNF-α [SMD: -0.35 (95 % CI: -0.70 to -0.00), p = 0.04], and increased LDL [WMD: 0.14 mmol/L (95 % CI: 0.02 to 0.26), p = 0.01] and lower-body muscular strength [SMD: 0.42 (95 % CI: 0.01 to 0.84), p = 0.04]. However, omega-3 supplementation with exercise training had no additional effects compared with training alone, for other body composition or cardiometabolic outcomes.

CONCLUSION

This systematic review and meta-analyses suggestes that adding omega-3 supplementation to exercise training may augment some effects of exercise training on body composition and cardiometabolic health in adults, although such effects appear to be modest.

Lack of evidence for Omega-3 fatty acid supplementation in enhancing lean mass, muscle strength, and physical function in healthy adults and clinical populations: An overview of reviews

BACKGROUND & AIMS

N-3 (omega-3) polyunsaturated fatty acids (n-3-PUFA) have been hypothesized to enhance/maintain skeletal muscle mass, strength, and physical function. We conducted an overview of reviews of n-3 fatty acid monotherapy supplementation and examined whether the evidence supports the effects in healthy young and old adults and clinical populations.

METHODS

In line with the PRISMA guidelines, a widely accepted framework for conducting and reporting systematic reviews, we conducted a comprehensive search for systematic reviews (OVID, Embase, Web of Science, SPORTDiscus) reporting the effect of n-3 fatty acid supplementation in our target populations. To ensure the reliability and validity of our findings, the methodological quality of the reviews was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR) 1, a validated tool for appraising the methodological quality of systematic reviews.

RESULTS

Thirty-three systematic reviews met our inclusion criteria: 19 non-oncologic, 11 oncologic, and 3 mixed. In non-oncologic populations, 4 out of 16 reviews showed some evidence that n-3-PUFA supplementation benefitted lean mass, with 3 reviews focusing on older populations. For strength, 1 out of 14 reviews found sufficient evidence in favor, while 3 others reported some evidence of n-3-PUFA ingestion. For physical function, 1 out of 15 reviews found sufficient evidence, and 3 reported some evidence favoring n-3-PUFA use. In oncologic participants, only 1 out of 13 reviews found sufficient evidence that n-3-PUFA improved lean mass. No reviews found sufficient evidence for strength or physical function improvements.

CONCLUSIONS

Our analysis indicates limited evidence supporting the effectiveness of n-3-PUFA supplementation in both younger and older healthy adults, as well as clinical populations including oncologic patients, to improve or prevent loss of lean mass. Most systematic reviews concluded that n-3-PUFA supplementation did not significantly affect strength, or studies were inconclusive, and there was no consistent impact of n-3-PUFA supplementation on functional outcome measures. These findings underscore the need for further research to better understand the role of n-3-PUFA in muscle health and to guide clinical practice. Our analysis does not support n-3-PUFA monotherapy for lean mass gain/retention enhancing strength or function in healthy young and older persons, and oncologic populations.

Erythrocyte Fatty Acid Patterns Are Associated with Skeletal Muscle Mass in Chinese Children

BACKGROUND

Nutritional factors are important for skeletal muscle mass and grip strength development in children.

OBJECTIVES

This study aimed to investigate the relationship between erythrocyte membrane fatty acid patterns (FAPs) and skeletal muscle mass and grip strength in children.

METHODS

A total of 452 children aged 6-9 y were included in this study. Appendicular skeletal muscle mass (ASM) was assessed by dual-energy X-ray absorptiometry. Hand grip strength was determined by the Jamar Plus+ hand dynamometer (Sammons Preston). Appendicular skeletal muscle mass index (ASMI) was calculated, and the relative concentrations of 20 fatty acids in erythrocyte membranes were measured by gas chromatography-mass spectrometry. Factor analysis was used to explore the relationship between fatty acids and skeletal muscle mass and grip strength.

RESULTS

Five FAPs were identified by factor analysis, and after adjusting for covariates, a multiple linear regression model showed that FAP2 (high C17:0, C20:5 n-3, C22:6 n-3) showed a negative correlation with ASM (β = -0.214; P < 0.001), ASMI (β = -0.085; P < 0.001), and left-hand grip strength (β = -0.235; P = 0.012). FAP3 (high C14:0, C15:0, C16:0, C16:1 n-7, low C20:4 n-6) scores were positively correlated with ASM (β = 0.134, P = 0.017). No other associations between FAPs and skeletal muscle mass were found.

CONCLUSIONS

The relationship between different FAPs and skeletal muscle health in children aged 6-9 y may be different. The pattern characterized by higher concentrations of C17:0, C20:5 n-3, and C22:6 n-3 in erythrocyte membranes may be associated with lower skeletal muscle mass. The pattern featuring higher concentrations of C14:0, C15:0, C16:0, and C16:1 n-7 and lower concentrations of C20:4 n-6 may be protective factors for muscle mass.

FOXO regulation of TXNIP induces ferroptosis in satellite cells by inhibiting glutathione metabolism, promoting Sarcopenia

Aging-related sarcopenia represents a significant health concern due to its impact on the quality of life in the elderly. This study elucidates the molecular mechanisms underlying sarcopenia by employing single-cell sequencing and public transcriptome databases to compare young and aged mouse skeletal muscles. Cellular classification and pseudotime analyses differentiated cell types and their interrelationships, revealing a marked reduction in satellite cell numbers and a consistent upregulation of TXNIP (Thioredoxin interacting protein) across various muscle cell populations in aged mice. Further transcriptomic data integration and batch correction from the GEO (Gene Expression Omnibus) database highlighted key differentially expressed genes. The role of TXNIP and its transcriptional regulation by FOXO1 (Forkhead box O1) was confirmed through in vitro experiments, which demonstrated FOXO1's influence on TXNIP expression and its subsequent suppression of glutathione metabolism, leading to satellite cell ferroptosis. Additionally, in vivo studies showed that overexpression of TXNIP in young mice's muscle tissues significantly reduced muscle mass, suggesting its potential role in the initiation of sarcopenia. Our findings suggest that FOXO1-mediated regulation of TXNIP and the disruption of glutathione metabolism are central to the process of sarcopenia, offering new insights into its pathogenesis.

The Optimal Dosage and Duration of ω-3 PUFA Supplementation in Heart Failure Management: Evidence from a Network Meta-Analysis

Heart failure is a progressive condition associated with a high mortality rate. Despite advancements in treatment, many patients continue to experience less-than-ideal outcomes. ω-3 (n-3) polyunsaturated fatty acids (PUFAs) have been studied as a potential supplementary therapy for heart failure, but the optimal dosage and duration of supplementation remain unclear. This network meta-analysis (NMA) aimed to assess the efficacy of various n-3 PUFA supplementation regimens in patients with heart failure, focusing on dose-dependent and time-dependent effects. We conducted a systematic search for randomized controlled trials (RCTs) on n-3 PUFA supplementation in heart failure till 13 September, 2024. The primary outcome was the change in heart function, specifically left ventricular ejection fraction. Secondary outcomes included changes in peak oxygen consumption (VO2), blood B-type natriuretic peptide concentrations, and quality of life. The safety analysis focused on dropout rates (i.e., patients leaving the study for any reason before completion) and all-cause mortality. A frequentist-based NMA was performed. This NMA, which included 14 RCTs with 9075 participants (mean age, 66.0 y; 23.3% female), found that high-dose n-3 PUFA supplementation (2000-4000 mg/d) over a duration of ≥1 y significantly improved left ventricular ejection fraction and peak VO2 compared with those of control groups. Lower doses and shorter treatment periods did not produce the same benefits. No significant differences were found in dropout rates or all-cause mortality between the n-3 PUFAs and control groups. Long-term, high-dose n-3 PUFA supplementation, particularly with a predominance of docosahexaenoic acid or eicosapentaenoic acid, enhances cardiac function in patients with heart failure without increasing risk of adverse events. Further well-designed RCTs with long treatment durations (i.e., >1 y) and stringent heart failure inclusion criteria are necessary to confirm these findings and reduce potential biases. This trial was registered at PROSPERO as CRD42024590476.

Medical Nutrition Therapy and Physical Exercise for Acute and Chronic Hyperglycemic Patients with Sarcopenia

A wide range of factors contribute to the overlap of hyperglycemia-acute or chronic-and sarcopenia, as well as their associated adverse consequences, which can lead to impaired physical function, reduced quality of life, and increased mortality risk. These factors include malnutrition (both overnutrition and undernutrition) and low levels of physical activity. Hyperglycemia and sarcopenia are interconnected through a vicious cycle of events that mutually reinforce and worsen each other. To explore this association, our review compiles evidence on: (i) the impact of hyperglycemia on motor and muscle function, with a focus on the mechanisms underlying biochemical changes in the muscles of individuals with or at risk of diabetes and sarcopenia; (ii) the importance of the clinical assessment and control of sarcopenia under hyperglycemic conditions; and (iii) the potential benefits of medical nutrition therapy and increased physical activity as muscle-targeted treatments for this population. Based on the reviewed evidence, we conclude that a regular intake of key functional nutrients, together with structured and supervised resistance and/or aerobic physical activity, can help maintain euglycemia and improve muscle status in all patients with hyperglycemia and sarcopenia.

Nutritional specificity of frailty: from epidemiological and clinical evidence to potential mechanisms

PURPOSE OF REVIEW

Considering the ageing of the population, age-related syndromes, such as frailty, are prominent. In this context, nutrition is a modifiable factor considered a key nonpharmacological approach to prevention and treatment. Yet, its contribution to the frailty pathophysiology is conflicting in the literature. This paper discusses the recent literature (January 2023-June 2024) on the implication of nutrition in frailty management.

RECENT FINDINGS

Malnutrition is one of the main frailty risk factors. Proteins are the targeted macronutrient for their effects on muscle anabolism, not only in terms of quantity consumed but also in terms of sources. The diversity in plant and animal sources demonstrates better results than relying on a single source. More globally, anti-inflammatory and antioxidant diets are associated with a lower risk of frailty, like the Mediterranean Diet and specific food groups, like seafood, nuts, and seeds. Nutrition is pivotal in frailty prevention and treatment, and multidomain interventions providing exercises seem to yield even better results.

SUMMARY

Diverse protein sources and anti-inflammatory and antioxidant diets associated with exercises are the primary recommendations for frailty prevention and treatment. However, there is a need to evaluate how to achieve and maintain this healthy behaviour in real life.

Omega-3 Fatty Acids and Muscle Strength-Current State of Knowledge and Future Perspectives

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), specifically the most biologically active (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), have well-documented health-promoting effects, including, but not limited to, controlling inflammatory processes in the human body and supporting cardiovascular and cognitive health and visual processes. There is also some evidence pointing to the potential of EPA and DHA to preserve and/or enhance muscle strength. Muscle strength plays a crucial role in preventing age-related decline in skeletal muscle mass and function and the subsequent impaired functionality in the daily lives of the elderly. It also has a significant role in physical performance by aiding in the effectiveness of training elements, such as vertical jumps, sprinting, changes of direction, rate of force development, and anaerobic conditioning. Previous studies have indicated that supplementation with n-3 PUFAs may have a small but significant effect on preserving and/or increasing muscle strength in both healthy adults and in elderly. However, the number of studies published on this topic is limited. The goal of this narrative review is to summarize the effects of EPA and DHA supplementation on muscle strength and identify the limitations of previous studies that, if addressed, will help confirm or exclude the beneficial effects of n-3 PUFAs on muscle strength in humans.

Sarcopenia in the era of precision health: Toward personalized interventions for healthy longevity

Sarcopenia, characterized by the progressive loss of skeletal muscle mass and function, significantly impacts health outcomes in older adults. This review explores the evolving landscape of sarcopenia research, with a particular focus on its unique characteristics in Asian populations and emerging pharmaceutical interventions. Recent studies have revealed distinct patterns of muscle mass decline in Asian adults, particularly in women, challenging the universal application of global sarcopenia diagnostic criteria. The Asian Working Group for Sarcopenia has proposed region-specific diagnostic criteria, acknowledging these ethnic variations. Prevalence estimates of sarcopenia vary widely, ranging from 10% to 40% in community-dwelling older adults. For specific chronic conditions, the prevalence of sarcopenia is notably higher, reaching 35% for cardiovascular diseases and 24.5% for chronic kidney disease. Sarcopenia is strongly associated with various chronic conditions, increasing the risk of falls by 1.5 to 3 times and significantly increasing mortality risk by 29% to 51%. Current management strategies primarily involve resistance exercise and nutritional interventions, with a recommended daily protein intake of at least 1.2 g/kg to maintain muscle health. Pharmaceutical development has gained significant momentum, with over 20 compounds in various stages of clinical trials. These include myostatin inhibitors, selective androgen receptor modulators, ghrelin receptor agonists, mesenchymal stem cell therapy, and follistatin gene therapy. However, the unique dietary patterns, cultural contexts, and potentially distinct drug responses in Asian populations necessitate tailored interventions and Asia-specific clinical trials. Future directions include refining Asian-specific diagnostic criteria, conducting large-scale epidemiological studies across multiple Asian countries, developing culturally appropriate interventions, integrating sarcopenia management into chronic disease care, and advancing pharmaceutical research with a focus on Asian populations. In conclusion, sarcopenia emerges as a critical nexus in the aging process, intricately linked with multiple organ systems and chronic conditions, underscoring the imperative for its recognition as a cornerstone in person-centered care and the holistic management of age-related health challenges.

Long-chain n-3 polyunsaturated fatty acid supplementation and neuromuscular function in older adults

PURPOSE OF REVIEW

This review aims to explore the latest research investigating the effects of marine-derived long-chain n -3 polyunsaturated fatty acid (LC n -3 PUFA) supplementation on neuromuscular function in older adults.

RECENT FINDINGS

Ageing results in a decline in skeletal muscle strength and mass. There is growing evidence that LC n -3 PUFA supplementation increases muscle strength and mass in healthy older adults, yet the mechanisms underlying these effects remain elusive. Recent studies investigating LC n -3 PUFA supplementation have demonstrated effects on neuromuscular function such as increases in the compound muscle action potential (M-wave) amplitude and surface electromyography alongside increases in muscular strength. Therefore, evidence suggests that LC n -3 PUFA may elicit a beneficial effect at the neuromuscular junction and possess neuroprotective properties in older adults.

SUMMARY

LC n -3 PUFA supplementation may increase or maintain neuromuscular function throughout the ageing process. Further research is warranted to investigate the long-term effects LC n -3 PUFA supplementation on neuromuscular outcomes such as single motor unit properties and cortical/supraspinal networks, utilizing state-of-the-art techniques in neuromuscular physiology.

Association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and sarcopenia in individuals with cancer: a cross-sectional study

BACKGROUND

Cancer and sarcopenia are both closely related to lipid metabolism, but the relationship between lipid metabolism and patients with cancer and sarcopenia has not been thoroughly studied. The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) is a reliable measure of lipid metabolism. The purpose of this study was to determine the possible relationship between the NHHR and sarcopenia in individuals with cancer.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) database for individuals with cancer, with and without sarcopenia was analyzed using weighted multiple regression equations, weighted regression cubic spline (RCS) analysis, and weighted subgroup analysis.

RESULTS

In total, 1,602 individuals with cancer were included, of whom 17.1% had sarcopenia. In Adjusted Model 2, the occurrence of sarcopenia was found to be significantly associated with a higher NHHR in cancer (95% confidence interval [CI]:1.01-1.39, P = 0.036). Individuals with high a NHHR had a 2.09-fold higher risk of developing sarcopenia in comparison to those with a low NHHR (95% CI:1.12-3.92, P = 0.022). RCS analysis further identified a U-shaped non-linear relationship between females with cancer and the muscle index. Subgroup analysis indicated that sex was a significant stratifying factor, whereas age, race, marital status, smoking and drinking habits, and history of cardiovascular disease, arthritis, hypertension, and diabetes had no significant impact.

CONCLUSION

From the perspective of lipid metabolism, the NHHR may serve as an indicator for monitoring and preventing the occurrence of sarcopenia in individuals with cancer, particularly for females with cancer who appear to have greater sensitivity.

Nutrition of aging people with diabetes mellitus: Focus on sarcopenia

As populations age, chronic diseases accumulate, and new health conditions emerge. One noteworthy pair that warrants further evaluation is diabetes mellitus and sarcopenia, given that the latter occurs in 28 % of the population aged over 50 who have diabetes mellitus. The management of both entails nutritional interventions, making the development of unified dietary recommendations an alluring strategy. This review aims to elucidate the current recommendations for the combined management of sarcopenia and diabetes, while featuring elements that require further research. The goal of nutritional management is to improve muscle mass and strength while regulating metabolic risk and glucose levels. To ensure muscle synthesis in the elderly, recommendations align at daily calorie intake that exceeds 30 kcal/kg, with adjustments based on comorbidities. Additionally, a protein intake of at least 1-1.2 g/kg/d is essential, emphasizing both daily and per-meal intake, and can be achieved through diet or branched-amino-acids supplements. Specific considerations for diabetes include restricted protein intake in diabetic nephropathy and exploring the potential link between branched amino acids and insulin resistance. Further recommendations that both promote metabolic health and have demonstrated at least a potential to increase muscle strength include prioritizing polyunsaturated fatty acids as a fat source and maintaining adequate levels of vitamin D. Clinicians should consult their patients on dietary optimization, but evidence is insufficient to recommend additional supplementation. Lastly, an emerging challenge of diabetes and sarcopenia is sarcopenic obesity, which requires the combination of a hypocaloric diet with increased protein intake.

Omega-3 polyunsatured fatty acids and physical performance across the lifespan: a narrative review

Background and Aims

Physical performance is a major contributor of mobility and independence during older life. Despite a progressive decline in musculoskeletal function starts from middle age, several factors acting during the life-course can negatively influence musculoskeletal functional capacities. Lifestyle interventions incorporating nutrition and physical exercise can help maximizing the muscle functional capacities in early life as well as preserving them later in life. Among various dietary compounds, omega-3 polyunsaturated fatty acids (PUFAs) are gaining growing attention for their potential effects on muscle membrane composition and muscle function. Indeed, several pathways are enhanced, such as an attenuation of pro-inflammatory oxidative stress, mitochondrial function, activation of the mammalian target of rapamycin (mTOR) signaling and reduction of insulin resistance.

Methods

We performed a narrative review to explore the existing literature on the relationship between omega-3 PUFAs and physical performance across the life-course.

Results

Growing evidence from randomized controlled trials (RCTs) suggests beneficial effects of omega-3 PUFAs on muscle function, including physical performance parameters in mid to later life. On the other hand, despite a direct association in early life is not available in literature, some mechanisms by which omega-3 PUFAs may contribute to improved adult physical performance could be hypothesized.

Conclusion

Omega-3 PUFAs are gaining growing attention for their positive effect on muscle function parameters. The integration of physical function measures in future studies would be of great interest to explore whether omega-3 PUFAs could contribute to improved muscle function, starting from early life and extending throughout the lifespan. However, larger and high-quality RCTs are needed to fully elucidate the beneficial effects of omega-3 PUFAs supplementation on muscle mass and function.

Navigating the Intersection: Sarcopenia and Sarcopenic Obesity in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are intricate systemic conditions that can extend beyond the gastrointestinal tract through both direct and indirect mechanisms. Sarcopenia, characterized by a reduction in muscle mass and strength, often emerges as a consequence of the clinical course of IBDs. Indeed, sarcopenia exhibits a high prevalence in Crohn's disease (52%) and ulcerative colitis (37%). While computed tomography and magnetic resonance imaging remain gold-standard methods for assessing muscle mass, ultrasound is gaining traction as a reliable, cost-effective, and widely available diagnostic method. Muscle strength serves as a key indicator of muscle function, with grip strength test emerging nowadays as the most reliable assessment method. In IBDs, sarcopenia may arise from factors such as inflammation, malnutrition, and gut dysbiosis, leading to the formulation of the 'gut-muscle axis' hypothesis. This condition determines an increased need for surgery with poorer post-surgical outcomes and a reduced response to biological treatments. Sarcopenia and its consequences lead to reduced quality of life (QoL), in addition to the already impaired QoL. Of emerging concern is sarcopenic obesity in IBDs, a challenging condition whose pathogenesis and management are still poorly understood. Resistance exercise and nutritional interventions, particularly those aimed at augmenting protein intake, have demonstrated efficacy in addressing sarcopenia in IBDs. Furthermore, anti-TNF biological therapies showed interesting outcomes in managing this condition. This review seeks to furnish a comprehensive overview of sarcopenia in IBDs, elucidating diagnostic methodologies, pathophysiological mechanisms, and clinical implications and management. Attention will also be paid to sarcopenic obesity, exploring the pathophysiology and possible treatment modalities of this condition.

The causal relationship between sarcopenia-related traits and ischemic stroke: Insights from univariable and multivariable Mendelian randomization analyses

AIMS

The causal relationship between sarcopenia-related traits and ischemic stroke (IS) remains poorly understood. This study aimed to explore the causal impact of sarcopenia-related traits on IS and to identify key mediators of this association.

METHODS

We conducted univariable, multivariable two-sample, and two-step Mendelian randomization (MR) analyses using genome-wide association study (GWAS) data. This included data for appendicular lean mass (ALM), hand grip strength (HGS), and usual walking pace (UWP) from the UK Biobank, and IS data from the MEGASTROKE consortium. Additionally, 21 candidate mediators were analyzed based on their respective GWAS data sets.

RESULTS

Each 1-SD increase in genetically proxied ALM was associated with a 7.5% reduction in the risk of IS (95% CI: 0.879-0.974), and this correlation remained after controlling for levels of physical activity and adiposity-related indices. Two-step MR identified that six mediators partially mediated the protective effect of higher ALM on IS, with the most significant being coronary heart disease (CHD, mediating proportion: 39.94%), followed by systolic blood pressure (36.51%), hypertension (23.87%), diastolic blood pressure (15.39%), type-2 diabetes mellitus (T2DM, 12.71%), and low-density lipoprotein cholesterol (7.97%).

CONCLUSION

Our study revealed a causal protective effect of higher ALM on IS, independent of physical activity and adiposity-related indices. Moreover, we found that higher ALM could reduce susceptibility to IS partially by lowering the risk of vascular risk factors, including CHD, hypertension, T2DM, and hyperlipidemia. In brief, we elucidated another modifiable factor for IS and implied that maintaining sufficient muscle mass may reduce the risk of such disease.

Nutritional Strategies for Muscle Atrophy: Current Evidence and Underlying Mechanisms

Skeletal muscle can undergo detrimental changes in various diseases, leading to muscle dysfunction and atrophy, thus severely affecting people's lives. Along with exercise, there is a growing interest in the potential of nutritional support against muscle atrophy. This review provides a brief overview of the molecular mechanisms driving skeletal muscle atrophy and summarizes recent advances in nutritional interventions for preventing and treating muscle atrophy. The nutritional supplements include amino acids and their derivatives (such as leucine, β-hydroxy, β-methylbutyrate, and creatine), various antioxidant supplements (like Coenzyme Q10 and mitoquinone, resveratrol, curcumin, quercetin, Omega 3 fatty acids), minerals (such as magnesium and selenium), and vitamins (such as vitamin B, vitamin C, vitamin D, and vitamin E), as well as probiotics and prebiotics (like Lactobacillus, Bifidobacterium, and 1-kestose). Furthermore, the study discusses the impact of a combined approach involving nutritional support and physical therapy to prevent muscle atrophy, suggests appropriate multi-nutritional and multi-modal interventions based on individual conditions to optimize treatment outcomes, and enhances the recovery of muscle function for patients. By understanding the molecular mechanisms behind skeletal muscle atrophy and implementing appropriate interventions, it is possible to enhance the recovery of muscle function and improve patients' quality of life.

Restoration of epigenetic impairment in the skeletal muscle and chronic inflammation resolution as a therapeutic approach in sarcopenia

Sarcopenia is an age-associated loss of skeletal muscle mass, strength, and function, accompanied by severe adverse health outcomes, such as falls and fractures, functional decline, high health costs, and mortality. Hence, its prevention and treatment have become increasingly urgent. However, despite the wide prevalence and extensive research on sarcopenia, no FDA-approved disease-modifying drugs exist. This is probably due to a poor understanding of the mechanisms underlying its pathophysiology. Recent evidence demonstrate that sarcopenia development is characterized by two key elements: (i) epigenetic dysregulation of multiple molecular pathways associated with sarcopenia pathogenesis, such as protein remodeling, insulin resistance, mitochondria impairments, and (ii) the creation of a systemic, chronic, low-grade inflammation (SCLGI). In this review, we focus on the epigenetic regulators that have been implicated in skeletal muscle deterioration, their individual roles, and possible crosstalk. We also discuss epidrugs, which are the pharmaceuticals with the potential to restore the epigenetic mechanisms deregulated in sarcopenia. In addition, we discuss the mechanisms underlying failed SCLGI resolution in sarcopenia and the potential application of pro-resolving molecules, comprising specialized pro-resolving mediators (SPMs) and their stable mimetics and receptor agonists. These compounds, as well as epidrugs, reveal beneficial effects in preclinical studies related to sarcopenia. Based on these encouraging observations, we propose the combination of epidrugs with SCLI-resolving agents as a new therapeutic approach for sarcopenia that can effectively attenuate of its manifestations.

Relationship between Eating Alone and Handgrip Strength in Korean Older Adults

Sarcopenia is defined as an age-related decline in muscle mass, muscle strength, and physical performance. Eating alone has been linked to various health issues in older adults. This study investigated the relationship between eating alone and handgrip strength (HGS) in older adults using data from 7278 individuals (≥65 years) who participated in the 2014-2019 Korea National Health and Nutrition Examination Survey. HGS was measured using a digital grip strength dynamometer, relative HGS was calculated by dividing HGS by body mass index, and dynapenia was defined as an HGS < 28 kg for men and <18 kg for women. Multivariable logistic regression analysis showed that women who ate two meals alone were more likely to exhibit dynapenia than those who never ate alone (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.03-1.77). If the groups that never ate alone or ate one meal alone were combined as the reference group, the probability of dynapenia was higher in the combined groups that ate two or three meals alone (OR, 1.25; 95% CI, 1.04-1.50). No association was observed between eating alone and dynapenia in men. This suggests that eating alone is a modifiable related factor of dynapenia in older women.

The Vicious Cycle of Type 2 Diabetes Mellitus and Skeletal Muscle Atrophy: Clinical, Biochemical, and Nutritional Bases

Today, type 2 diabetes mellitus (T2DM) and skeletal muscle atrophy (SMA) have become increasingly common occurrences. Whether the onset of T2DM increases the risk of SMA or vice versa has long been under investigation. Both conditions are associated with negative changes in skeletal muscle health, which can, in turn, lead to impaired physical function, a lowered quality of life, and an increased risk of mortality. Poor nutrition can exacerbate both T2DM and SMA. T2DM and SMA are linked by a vicious cycle of events that reinforce and worsen each other. Muscle insulin resistance appears to be the pathophysiological link between T2DM and SMA. To explore this association, our review (i) compiles evidence on the clinical association between T2DM and SMA, (ii) reviews mechanisms underlying biochemical changes in the muscles of people with or at risk of T2DM and SMA, and (iii) examines how nutritional therapy and increased physical activity as muscle-targeted treatments benefit this population. Based on the evidence, we conclude that effective treatment of patients with T2DM-SMA depends on the restoration and maintenance of muscle mass. We thus propose that regular intake of key functional nutrients, along with guidance for physical activity, can help maintain euglycemia and improve muscle status in all patients with T2DM and SMA.

Network Meta-analysis of Different Treatments for Vestibular Migraine

INTRODUCTION

Although one of the major presentations of vestibular migraine is dizziness with/without unsteady gait, it is still classified as one of the migraine categories. However, in contrast to ordinary migraine, vestibular migraine patients have distinct characteristics, and the detailed treatment strategy for vestibular migraine is different and more challenging than ordinary migraine treatment. Currently, there is no conclusive evidence regarding its management, including vestibular migraine prophylaxis.

AIM

The objective of this current network meta-analysis (NMA) was to compare the efficacy and acceptability of individual treatment strategies in patients with vestibular migraine.

METHODS

The PubMed, Embase, ScienceDirect, ProQuest, Web of Science, ClinicalKey, Cochrane Central, and ClinicalTrials.gov databases were systematically searched for randomized controlled trials (RCTs), with a final literature search date of 30 December 2022. Patients diagnosed with vestibular migraine were included. The PICO of the current study included (1) patients with vestibular migraine; (2) intervention: any active pharmacologic or non-pharmacologic intervention; (3) comparator: placebo-control, active control, or waiting list; and (4) outcome: changes in migraine frequency or severity. This NMA of RCTs of vestibular migraine treatment was conducted using a frequentist model. We arranged inconsistency and similarity tests to re-examine the assumption of NMA, and also conducted a subgroup analysis focusing on RCTs of pharmacological treatment for vestibular migraine management. The primary outcome was changes in the frequency of vestibular migraines, while the secondary outcomes were changes in vestibular migraine severity and acceptability. Acceptability was set as the dropout rate, which was defined as the participant leaving the study before the end of the trial for any reason. Two authors independently evaluated the risk of bias for each domain using the Cochrane risk-of-bias tool.

RESULTS

Seven randomized controlled trials (N = 828, mean age 37.6 years, 78.4% female) and seven active regimens were included. We determined that only valproic acid (standardized mean difference [SMD] -1.61, 95% confidence interval [CI] -2.69, -0.54), propranolol (SMD -1.36, 95% CI -2.55, -0.17), and venlafaxine (SMD -1.25, 95% CI -2.32, -0.18) were significantly associated with better improvement in vestibular migraine frequency than the placebo/control groups. Furthermore, among all the investigated pharmacologic/non-pharmacologic treatments, valproic acid yielded the greatest decrease in vestibular migraine frequency among all the interventions. In addition, most pharmacologic/non-pharmacologic treatments were associated with similar acceptability (i.e. dropout rate) as those of the placebo/control groups.

CONCLUSIONS

The current study provides evidence that only valproic acid, propranolol, and venlafaxine might be associated with beneficial efficacy in vestibular migraine treatment.

TRIAL REGISTRATION

CRD42023388343.