Protein and exercise in the prevention of sarcopenia and aging

The Impact of Exercise and Protein Intake on Inflammaging: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

CONTEXT

Sarcopenia and cachexia lead to muscle wasting and increased health risks in older adults. Both sarcopenia and cachexia are associated with inflammaging, a chronic low-grade inflammatory state linked to aging. Strategies to preserve muscle mass and function are crucial for maintaining independence and quality of life among the elderly.

OBJECTIVE

This meta-analysis and systematic review was conducted to comprehensively assess the individual and combined effects of exercise training and protein supplementation on circulatory markers of inflammation in older adults.

DATA SOURCES

A systematic search of the PubMed, Scopus, Cochrane CENTRAL, and SPORTDiscus databases was conducted to identify relevant studies published until January 2024.

DATA EXTRACTION

The search focused on randomized controlled trials examining the impact of exercise training (Ex), protein consumption (Pro), or their combination (Ex-Pro) on inflammatory factors, including C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) compared with a control (Con).

DATA ANALYSIS

The meta-analysis revealed a significant decrease in CRP levels in the Ex vs Pro (P = .0003) and the Ex-Pro (P < .00001) group compared with the Ex group and in overall experimental (EXPL) subgroups (P = .0002) compared with the Con group. A similar reduction was found in IL-6 in the Ex group (P = .001), Ex-Pro group (P = .05), and EXPL (P = .0002) subgroup compared with the Pro group. However, for TNF-α levels, a significant reduction was noted only in the Ex-Pro group compared with the Ex group (P < .00001).

CONCLUSION

Exercise training and protein supplementation, particularly when combined, show greater benefits in mitigating inflammaging. These findings highlight the importance of combined interventions against muscle wasting. Future studies and meta-analyses should further address the effects of Ex and Pro and Ex-Pro on inflammatory markers of older adults, considering specific conditions and larger sample sizes to identify optimal strategies for the aging population.

Narrative review: nutritional strategies for ageing populations - focusing on dysphagia and geriatric nutritional needs

The increase in elderly populations worldwide highlights the urgency of addressing age-related problems through effective nutritional management to enhance the well-being of the elderly and for the prevention and treatment of various diseases. The trend towards an increasing elderly population brings with it an increase in conditions such as sarcopenia, osteosarcopenia and frailty, emphasising the importance of regular checks for malnutrition in the elderly and the implementation of personalised nutritional therapies. The importance of nutrition in addressing geriatric syndromes such as frailty, sarcopenia, osteosarcopenia, obesity and metabolic syndrome is highlighted. Dysphagia, frequent in the elderly, requires special attention to prevent malnutrition and complications. It is essential to maintain muscle mass and bone health in old age. In this review we investigate the fundamental role of nutrition in geriatrics, focusing on promoting healthy ageing and managing problems such as malnutrition and overeating. The importance of protein intake and healthy dietary patterns such as the Mediterranean diet are then discussed. Finally, the challenges of personalised nutritional care, including the need for artificial nutrition or oral supplements, to improve quality of life and health care in an ageing society are addressed.

Effect of Protein Supplementation Combined With Resistance Training in Gait Speed in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

We aimed to evaluate the effectiveness of the combination of protein supplementation and resistance training (RT), compared with RT alone or combined with a placebo, in improving gait speed.

METHODS

We searched PubMed, Web of Science, Cochrane Library, and SPORTDiscus databases, and 18 randomized controlled trials with 1,147 older participants were included for meta-analysis. Data were pooled as the effect sizes (Hedges' g) with 95% confidence interval (CI) of the gait speed (in meters per second). The random-effect meta-analysis, subgroup analyses, meta-regression, and sensitivity analysis were conducted.

RESULTS

The combination of protein supplementation and RT significantly improved gait speed (Hedges' g: 0.52 m/s, 95% confidence interval [0.17, 0.86], p = .005; I2 = 86.5%) compared with the RT alone. The subgroup analyses revealed that the significant improvement in gait speed postprotein intervention plus RT was observed only in participants who consumed protein after RT (Hedges' g: 0.90 m/s, 95% confidence interval [0.46, 1.33], p = .001; I2 = 79.6%). The pooled result did not significantly change after excluding any single study at one time or excluding smaller studies with large effect sizes.

CONCLUSIONS

Protein supplementation combined with RT could significantly improve the gait speed of older adults compared with RT alone. This positive effect is more pronounced in people who consume protein after RT.

Association of Dietary Patterns, Suspected Sarcopenia, and Frailty Syndrome among Older Adults in Poland-A Cross-Sectional Study

BACKGROUND

The association of sarcopenia and frailty syndrome with dietary patterns is not yet well recognized.

THE AIM

The aim of the study was to evaluate the association among dietary patterns, suspected sarcopenia, and frailty syndrome among older people in Poland.

METHODS

The study was conducted in 2022 and 2023 among people aged 55 and older. The sample was chosen arbitrarily. The following questionnaires were used in the study: the KomPAN (assessment of frequency of food intake and sociodemographic characteristics), the SARC-F (assessment of risk of sarcopenia), and the EFS (diagnosis of frailty syndrome). To confirm the suspicion of sarcopenia, muscle strength was assessed using the HGS and FTSST, and physical fitness was assessed using the GST. Based on the frequency of food consumption, 11 DPs (factors) were selected using PCA analysis. SARC-F, HGS, FTSST, and GST results were used to identify homogeneous groups (clusters) using cluster analysis, a k-means method.

RESULTS

Two clusters were identified: cluster 1 (the non-sarcopenic cluster, or nSC) and cluster 2 (the sarcopenic cluster, or SC). Associations between variables were assessed using logistic regression. Suspected sarcopenia was found in 32.0% of respondents, more in men than women, and more among those either over 75 or 65 and under. EFS results showed that the risk (22.1%) or presence of frailty syndrome (23.8%) was more common in men than women and more common in those aged 75 and older than in other age groups. Male gender; older age; and unfavorable dietary patterns, i.e., consumption of white bread and bakery products, white rice and pasta, butter, and potatoes (factor 1) and cheese, cured meat, smoked sausages, and hot dogs (factor 9), increased the likelihood of sarcopenia and frailty syndrome, while the pattern associated with fruit and water consumption (factor 7) had the opposite effect.

CONCLUSIONS

Confirmation of the importance of dietary patterns in the etiology and pathogenesis of sarcopenia and frailty syndrome should be documented in prospective cohort studies.

Aerobic exercise alleviates skeletal muscle aging in male rats by inhibiting apoptosis via regulation of the Trx system

Skeletal muscle aging in rats is a reduction in skeletal muscle mass caused by a decrease in the number or volume of skeletal muscle myofibers. Apoptosis has been recognized to play a key role in accelerating the process of skeletal muscle aging in rats. The thioredoxin (Trx) system is a widely expressed oxidoreductase system that controls the cellular reduction/oxidation state and has both potent anti-free radical damage and important pro-growth and apoptosis inhibitory functions. Previous studies have shown that exercise delays skeletal muscle aging. However, it is unclear whether exercise attenuates skeletal muscle aging via the Trx system. Therefore, the present study used the Trx system as an entry point to explore the effect of aerobic exercise to improve skeletal muscle aging in rats and its possible mechanisms, and to provide a theoretical basis for exercise to delay skeletal muscle aging in rats. It was shown that aerobic exercise in senescent rats resulted in increased gastrocnemius index, decreased body weight, increased endurance, decreased skeletal muscle cell apoptosis, increased activity and protein expression of the Trx system, and decreased expression of p38 and ASK1. Based on these findings, we conclude that 10 weeks of aerobic exercise may enhance the anti-apoptotic effect of Trx by up-regulating Trx and Trx reductase (TR) protein expression, which in turn increases Trx activity in rat skeletal muscle, and ultimately alleviates apoptosis in senescent skeletal muscle cells.

Deciphering the environmental chemical basis of muscle quality decline by interpretable machine learning models

BACKGROUND

Sarcopenia is known as a decline in skeletal muscle quality and function that is associated with age. Sarcopenia is linked to diverse health problems, including endocrine-related diseases. Environmental chemicals (ECs), a broad class of chemicals released from industry, may influence muscle quality decline.

OBJECTIVES

In this work, we aimed to simultaneously elucidate the associations between muscle quality decline and diverse EC exposures based on the data from the 2011-2012 and 2013-2014 survey cycles in the National Health and Nutrition Examination Survey (NHANES) project using machine learning models.

METHODS

Six machine learning models were trained based on the EC and non-EC exposures from NHANES to distinguish low from normal muscle quality index status. Different machine learning metrics were evaluated for these models. The Shapley additive explanations (SHAP) approach was used to provide explainability for machine learning models.

RESULTS

Random forest (RF) performed best on the independent testing data set. Based on the testing data set, ECs can independently predict the binary muscle quality status with good performance by RF (area under the receiver operating characteristic curve = 0.793; area under the precision-recall curve = 0.808). The SHAP ranked the importance of ECs for the RF model. As a result, several metals and chemicals in urine, including 3-phenoxybenzoic acid and cobalt, were more associated with the muscle quality decline.

CONCLUSIONS

Altogether, our analyses suggest that ECs can independently predict muscle quality decline with a good performance by RF, and the SHAP-identified ECs can be closely related to muscle quality decline and sarcopenia. Our analyses may provide valuable insights into ECs that may be the important basis of sarcopenia and endocrine-related diseases in United States populations.

Association between sarcopenia and hemoglobin level: a systematic review and meta-analysis

Background

Sarcopenia is a disease characterized by decreased skeletal muscle mass and function in elderly individuals. Decreased hemoglobin levels is a marker of anemia. According to reports, there may be an association between anemia and sarcopenia, but research is inconsistent. Therefore, this meta-analysis aims to explore the association between sarcopenia and low hemoglobin levels.

Methods

We searched PubMed, Embase, the Cochrane Library, Web of Science, Ovid, China National Knowledge Infrastructure (CNKI), and Wan Fang databases until September 2022. The present study included cross-sectional and case-control studies regarding low hemoglobin levels and sarcopenia. The studies were selected using inclusion and exclusion criteria. Studies were meta-analyzed by Review Manager 5.4 and Stata 16.0. We performed the heterogeneity test using the I 2 test. Subgroup analysis was carried out to explore the cause of heterogeneity. Egger test was used to evaluate publication bias.

Results

Out of 1,550 initial studies, 16 studies were meta-analyzed. Sarcopenia participants had significantly lower levels of hemoglobin than controls (MD = -0.53, 95% CI: -0.68 to -0.37, p < 0.001). Subgroup analysis, performed in China population reported lower hemoglobin levels in the sarcopenia population (MD = -0.49, 95% CI: -0.65 to -0.33, p < 0.001). And sarcopenia based on AWGS criteria reported lower hemoglobin levels (MD = -0.49, 95% CI: -0.65 to -0.33, p < 0.001). Among the population from hospitals and communities, patients with sarcopenia have lower hemoglobin levels.

Conclusion

Our meta-analysis found evidence that sarcopenia is associated with low hemoglobin levels. However, further large-scale prospective studies should be conducted in the future to further confirm our conclusions.

Systematic review registration

PROSPERO, CDR42024532252.

Oral tribology of dairy protein-rich emulsions and emulsion-filled gels affected by colloidal processing and composition

Designing nutritious food for the elderly population often requires significant quantities of leucine-rich whey proteins to combat malnutrition, yet high-protein formulations can cause mouth dryness and increased oral friction. This study investigated how various colloidal processing methods and compositions impact the in vitro oral tribological properties of protein-rich emulsions and emulsion-filled gels. Oil-in-water emulsions with oil fractions from 1 wt% to 20 wt% were prepared, alongside emulsion-filled gels containing whey protein isolate (WPI), hydrolysed whey protein (HWP), or a blend of both (10 wt% protein content). Two processing approaches were employed: creating emulsions with an initial 10 w% protein content (M1) and initially forming emulsions with 0.1 wt% protein content, then enriching to a final 10 wt% concentration (M2). The hypothesis was that formulations with HWP or method 2 (M2) would offer lubrication benefits by inducing droplet coalescence, aiding in the formation of a lubricating boundary tribofilm. Surprisingly, the tribological behavior of high-protein emulsions showed minimal dependence on oil droplet volume fraction. However, both HWP-based emulsions and those processed with M2 for WPI exhibited significant friction reduction, which may be attributed to the presence of coalesced oil droplets, supporting our hypothesis. Substituting 50 wt% of WPI with HWP in emulsion-filled gel boli resulted in very low friction coefficients in the boundary lubrication regime, suggesting oil droplet release from the gel matrix. These findings provide insights into designing high-protein foods with improved mouthfeel for the elderly population, necessitating further validation through sensory studies.

Sex-Specific Sarcopenia Prevalence and Risk Factors in the Korean Population: A Cross-Sectional Epidemiological Study

Background and Objective: This study aimed to identify the incidence of sarcopenia and disease risk factors in Korean adults and to provide data for sarcopenia prevention. Materials and Methods: Based on the Korea National Health and Nutrition Survey, 2008-2011, we selected 14,185 adults over the age of 20 who participated in sarcopenia diagnostic tests and health surveys. We analyzed sarcopenia risk factors using complex sample multi-logistic regression analysis. Results: The prevalence of sarcopenia in Korea was 31.3%, with 20.2% in men and 40.4% in women. In men, there was a higher risk of sarcopenia in those of older age, without a spouse, with a low body mass index (BMI), who never engage in resistance exercise, or who do mid-level intensity resistance exercises. In women, sarcopenia risk was higher in those in their 20s compared to those in their 60s, and risk factors included a low BMI, high-density lipoprotein cholesterol and waist circumference measurements, alcohol consumption, aerobic exercise, and resistance exercise. Conclusions: Interventions and lifestyle improvements will help prevent the onset of sarcopenia in elderly men and young women with risk factors such as a low BMI.

The impact of food insecurity on mental health among older adults residing in low- and middle-income countries: A systematic review

Over the past few years, food insecurity has been increasing globally due to the COVID-19 pandemic, climate change, economic downturns and conflict and a number of other intersecting factors. Older adults residing in low- and middle-income countries are more vulnerable to food insecurity. While the impacts of food insecurity on physical health outcomes have been thoroughly researched, the effect on mental health outcomes remains under-researched, especially among older adults. Hence, this systematic review aims to investigate existing literature to assess how food insecurity impacts the mental health of older persons residing in LMICs. A systematic search of six databases and Google for studies was conducted. The search was limited to studies written in English and published between 2000 to the present. We identified 725 studies, out of which 40 studies were selected for a full-text review and 12 studies were included for a final analysis. The significant finding in all the included studies was that food insecurity is associated with the worsening mental health of older adults. We also found a complex interplay of factors such as gender, age, rural/urban and health conditions associated with the aggravation of several mental health outcomes. The findings of this study illuminate the need for improved food programs to improve food security and, consequently, mental health among older adults.

Sarcopenia and risk factors among Japanese community-dwelling older adults during the COVID-19 pandemic: A cross-sectional study

The COVID-19 pandemic exposed older adults to high risk of sarcopenia. This study aimed to investigate the prevalence of sarcopenia and its risk factors among Japanese community-dwelling older adults during the COVID-19 pandemic. We collected data through questionnaires and physical measurements among 242 older adults. Sarcopenia was assessed using the Asian Working Group for Sarcopenia 2019 criteria. The results revealed that 14.5% had sarcopenia, which was significantly associated with age, nutritional status, number of prescription medications, body mass index, and self-rated health. On multivariate analysis, the risk of malnutrition was independently significantly associated with sarcopenia. Approximately 70% of participants reported decreased social interaction and going outside, but with no significant association with sarcopenia. In addition, approximately 65% of the participants had an exercise habit and went outside at least once a week, thus maintaining a good level of activity. These findings suggest that prevention of sarcopenia during the pandemic required provision of opportunities for older adults to remain active and positive assessment of nutritional status and well-being.

The effectiveness of protein supplementation combined with resistance exercise programs among community-dwelling older adults with sarcopenia: a systematic review and meta-analysis

OBJECTIVES

The combination of protein supplementation and resistance exercise shows promise for improving and maintaining muscle mass, strength, and performance in older adults with sarcopenia. This systematic review aimed to evaluate the effects of this combination on muscle mass, muscle strength, and physical performance in community-dwelling older adults with sarcopenia.

METHODS

We conducted a comprehensive search of 4 electronic databases: PubMed, Scopus, Embase, and the MEDLINE Library. The search covered literature from January 2013 to January 2023 and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two independent reviewers assessed the methodological quality of each study using the standard critical appraisal tool from the Joanna Briggs Institute (JBI). Meta-analysis was performed with the JBI Sumari program.

RESULTS

The review included 7 randomized controlled trials and 1 quasi-experimental study, encompassing a total of 854 participants aged 60 years and above. The study durations ranged from 10 weeks to 24 weeks. An analysis of standardized mean differences (SMDs) showed that protein supplementation combined with resistance exercise significantly increased muscle mass (SMD, 0.95; 95% confidence interval [CI], 0.13 to 1.78; p<0.05) and muscle strength (SMD, 0.32; 95% CI, 0.08 to 0.56; p<0.05).

CONCLUSIONS

Although the limited number of randomized controlled trials restricts the robustness of our conclusions, the evidence suggests that protein supplementation combined with resistance exercise is effective in enhancing muscle mass and strength in community-dwelling older adults with sarcopenia.

The Effect of Web-Based Culinary Medicine to Enhance Protein Intake on Muscle Quality in Older Adults: Randomized Controlled Trial

BACKGROUND

The most common age-related musculoskeletal disorder is sarcopenia. Sarcopenia is the progressive and generalized loss of muscle mass, strength, and function. The causes of sarcopenia can include insufficient nutritional status, which may be due to protein-energy malnutrition, anorexia, limited food access and eating ability, or malabsorption. In the United States, 15.51% of older adults have been diagnosed with sarcopenia. Culinary medicine (CM) is a novel evidence-based medical field that combines the science of medicine with food and cooking to prevent and treat potential chronic diseases. CM helps individuals learn and practice culinary skills while tasting new recipes. Therefore, this program could successfully reduce barriers to protein intake, enabling older adults to enhance their diet and muscle quality.

OBJECTIVE

This study aimed to examine how a web-based CM intervention, emphasizing convenient ways to increase lean red meat intake, could improve protein intake with the promotion of physical activity to see how this intervention could affect older adults' muscle strength and mass.

METHODS

A 16-week, single-center, parallel-group, randomized controlled trial was conducted to compare a web-based CM intervention group (CMG) with a control group (CG) while monitoring each group's muscle strength, muscle mass, and physical activity for muscle quality. The CMG received weekly web-based cooking demonstrations and biweekly nutrition education videos about enhancing protein intake, whereas the CG just received the recipe handout. Anthropometrics, muscle mass, muscle strength, dietary habits, physical activity, and cooking effectiveness were established at baseline and measured after the intervention. The final number of participants for the data analysis was 24 in the CMG and 23 in the CG.

RESULTS

No between-group difference in muscle mass (P=.88) and strength (dominant P=.92 and nondominant P=.72) change from the prestudy visit was detected. No statistically significant difference in protein intake was seen between the groups (P=.50). A nonsignificant time-by-intervention interaction was observed for daily protein intake (P=.08). However, a statistically significant time effect was observed (P≤.001). Post hoc testing showed that daily protein intake was significantly higher at weeks 1 to 16 versus week 0 (P<.05). At week 16, the intake was 16.9 (95% CI 5.77-27.97) g higher than that at the prestudy visit.

CONCLUSIONS

This study did not affect protein intake and muscle quality. Insufficient consistent protein intake, low physical activity, intervention adherence, and questionnaire accuracy could explain the results. These studies could include an interdisciplinary staff, different recruitment strategies, and different muscle mass measurements. Future research is needed to determine if this intervention is sustainable in the long term and should incorporate a follow-up to determine program efficacy on several long-term behavioral and health outcomes, including if the participants can sustain their heightened protein intake and how their cooking skills have changed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05593978; https://clinicaltrials.gov/ct2/show/NCT05593978.

Dietary protein intake in midlife in relation to healthy aging - results from the prospective Nurses' Health Study cohort

BACKGROUND

Protein intake plays an important role in maintaining the health status of older adults. However, few epidemiologic studies examined midlife protein intake in relation to healthy aging.

OBJECTIVES

The objective of this study was to evaluate the long-term role of dietary protein intake in healthy aging among female participants in the prospective Nurses' Health Study (NHS) cohort.

METHODS

We included 48,762 NHS participants aged <60 y in 1984. Total protein, animal protein, dairy protein (a subset of animal protein), and plant protein were derived from validated food frequency questionnaires. Healthy aging was defined as being free from 11 major chronic diseases, having good mental health, and not having impairments in either cognitive or physical function, as assessed in the 2014 or 2016 NHS participant questionnaires. We used multivariate logistic regression adjusted for lifestyle, demographics, and health status to estimate the odds ratios (ORs) and 95% confidence intervals for protein intake in relation to healthy aging.

RESULTS

A total of 3721 (7.6%) NHS participants met our healthy aging definition. Protein intake was significantly associated with higher odds of healthy aging. The ORs (95% confidence intervals) per 3%-energy increment with healthy aging were 1.05 (1.01, 1.10) for total protein, 1.07 (1.02, 1.11) for animal protein, 1.14 (1.06, 1.23) for dairy protein, and 1.38 (1.24, 1.54) for plant protein. Plant protein was also associated with higher odds of absence of physical function limitations and good mental status. In substitution analyses, we observed significant positive associations for the isocaloric replacement of animal or dairy protein, carbohydrate, or fat with plant protein (ORs for healthy aging: 1.22-1.58 for 3% energy replacement with plant protein).

CONCLUSIONS

Dietary protein intake, especially plant protein, in midlife, is associated with higher odds of healthy aging and with several domains of positive health status in a large cohort of female nurses.

Changes in lumbar muscle diffusion tensor indices with age

Objective

To investigate differences in diffusion tensor imaging (DTI) parameters and proton density fat fraction (PDFF) in the spinal muscles of younger and older adult males.

Methods

Twelve younger (19-30 years) and 12 older (61-81years) healthy, physically active male participants underwent T1W, T2W, Dixon and DTI of the lumbar spine. The eigenvalues (λ1, λ2, and λ3), fractional anisotropy (FA), and mean diffusivity (MD) from the DTI together with the PDFF were determined in the multifidus, medial and lateral erector spinae (ESmed, ESlat), and quadratus lumborum (QL) muscles. A two-way ANOVA was used to investigate differences with age and muscle and t-tests for differences in individual muscles with age.

Results

The ANOVA gave significant differences with age for all DTI parameters and the PDFF (P < .01) and with muscle (P < .01) for all DTI parameters except for λ1 and for the PDFF. The mean of the eigenvalues and MD were lower and the FA higher in the older age group with differences reaching statistical significance for all DTI measures for ESlat and QL (P < .01) but only in ESmed for λ3 and MD (P < .05).

Conclusions

Differences in DTI parameters of muscle with age result from changes in both in the intra- and extra-cellular space and cannot be uniquely explained in terms of fibre length and diameter.

Advances in knowledge

Previous studies looking at age have used small groups with uneven age spacing. Our study uses two well defined and separated age groups.

The potential of traditional herbal active ingredients in the treatment of sarcopenia animal models: focus on therapeutic effects and mechanisms

Sarcopenia is a major global public health problem that harms individual physical function. In 2018, the European Working Group on Sarcopenia in the Elderly 2 classified sarcopenia into primary and secondary sarcopenia. However, information on the pathogenesis and effective treatment of primary and secondary sarcopenia is limited. Traditional herbal active ingredients have biological activities that promote skeletal muscle health, showing potential preventive and therapeutic effects on sarcopenia. Therefore, this narrative review aims to provide a comprehensive overview of global traditional herbal active ingredients' beneficial therapeutic effects and molecular mechanisms on sarcopenia-related animal models. For this purpose, we conducted a literature search in three databases, PubMed, Web of Science, and Embase, consistent with the review objectives. After the screening, 12 animal studies met the review themes. The review results showed that the pathological mechanisms in sarcopenia-related animal models include imbalanced protein metabolism, oxidative stress, inflammation, apoptosis, insulin resistance, endoplasmic reticulum stress, impaired mitochondrial biogenesis, and autophagy-lysosome system aggravation. Eleven traditional herbal active ingredients exerted positive anti-sarcopenic effects by ameliorating these pathological mechanisms. This narrative review will provide meaningful insight into future studies regarding traditional herbal active ingredients for treating sarcopenia.

Physical exercise ameliorates age-related deterioration of skeletal muscle and mortality by activating Pten-related pathways in Drosophila on a high-salt diet

The phosphatase and tensin congeners (Pten) gene affects cell growth, cell proliferation, and rearrangement of connections, and it is closely related to cellular senescence, but it remains unclear the role of muscle-Pten gene in exercise against age-related deterioration in skeletal muscle and mortality induced by a high-salt diet (HSD). In here, overexpression and knockdown of muscle Pten gene were constructed by building MhcGAL4 /PtenUAS-overexpression and MhcGAL4 /PtenUAS-RNAi system in flies, and flies were given exercise training and a HSD for 2 weeks. The results showed that muscle Pten knockdown significantly reduced the climbing speed, climbing endurance, GPX activity, and the expression of Pten, Sirt1, PGC-1α genes, and it significantly increased the expression of Akt and ROS level, and impaired myofibril and mitochondria of aged skeletal muscle. Pten knockdown prevented exercise from countering the HSD-induced age-related deterioration of skeletal muscle. Pten overexpression has the opposite effect on skeletal muscle aging when compared to it knockdown, and it promoted exercise against HSD-induced age-related deterioration of skeletal muscle. Pten overexpression significantly increased lifespan, but its knockdown significantly decreased lifespan of flies. Thus, current results confirmed that differential expression of muscle Pten gene played an important role in regulating skeletal muscle aging and lifespan, and it also affected the adaptability of aging skeletal muscle to physical exercise since it determined the activity of muscle Pten/Akt pathway and Pten/Sirt1/PGC-1α pathway.

Potential application of anti-osteoporotic therapy to relieve sarcopenia in the elderly

Sarcopenia is a progressive and systemic skeletal muscle disorder associated with aging that usually occurs with age in the elderly. Sarcopenia currently lacks effective pharmacological treatment modalities. Multiple pharmacological intervention modalities are available for osteoporosis, a comprehensive disease characterized by decreased systemic bone mass, degradation of bone microarchitecture, and increased bone fragility. Several recent studies have shown an extremely strong correlation between sarcopenia and osteoporosis, leading to the concept of "osteosarcopenia". Therefore, it is possible to alleviate sarcopenia simultaneously by improving osteoporosis.

Type 2 Diabetes Mellitus and Sarcopenia as Comorbid Chronic Diseases in Older Adults: Established and Emerging Treatments and Therapies

Type 2 diabetes mellitus (T2DM) and sarcopenia (low skeletal muscle mass and function) share a bidirectional relationship. The prevalence of these diseases increases with age and they share common risk factors. Skeletal muscle fat infiltration, commonly referred to as myosteatosis, may be a major contributor to both T2DM and sarcopenia in older adults via independent effects on insulin resistance and muscle health. Many strategies to manage T2DM result in energy restriction and subsequent weight loss, and this can lead to significant declines in muscle mass in the absence of resistance exercise, which is also a first-line treatment for sarcopenia. In this review, we highlight recent evidence on established treatments and emerging therapies targeting weight loss and muscle mass and function improvements in older adults with, or at risk of, T2DM and/or sarcopenia. This includes dietary, physical activity and exercise interventions, new generation incretin-based agonists and myostatin-based antagonists, and endoscopic bariatric therapies. We also highlight how digital health technologies and health literacy interventions can increase uptake of, and adherence to, established and emerging treatments and therapies in older adults with T2DM and/or sarcopenia.

Accelerated Aging and the Life Course of Individuals Born Preterm

Individuals born preterm have shorter lifespans and elevated rates of chronic illness that contribute to mortality risk when compared to individuals born at term. Emerging evidence suggests that individuals born preterm or of low birthweight also exhibit physiologic and cellular biomarkers of accelerated aging. It is unclear whether, and to what extent, accelerated aging contributes to a higher risk of chronic illness and mortality among individuals born preterm. Here, we review accelerated aging phenotypes in adults born preterm and biological pathways that appear to contribute to accelerated aging. We highlight biomarkers of accelerated aging and various resiliency factors, including both pharmacologic and non-pharmacologic factors, that might buffer the propensity for accelerated aging among individuals born preterm.

Mitigating Sarcopenia with Diet and Exercise

Sarcopenia is the loss of muscle mass and function from aging, inactivity, or disuse. It is a comorbidity to numerous conditions that exacerbates their severity and adversely impacts activities of daily living. While sarcopenia now receives more attention from the medical community, people with sarcopenia as a comorbidity nevertheless still sometimes receives less attention than other presenting diseases or conditions. Inevitable doctors' visits or hospital stays for those with sarcopenia as a comorbidity have far higher healthcare costs than those without this condition, which imposes a greater financial burden on the medical insurance and healthcare industries. This review offers information and guidance on this topic. Treatments for sarcopenia include dietary, exercise, and pharmacological interventions. Yet, the latter treatment is only recommended in extreme cases as it may evoke numerous side effects and has little support in the scientific literature. Currently, a more holistic approach, with an emphasis on lifestyle modification, to reduce the likelihood of sarcopenia is examined. The current review discusses dietary and exercise interventions to limit the occurrence and severity of sarcopenia. References cited in this review conformed to the Declaration of Helsinki requirements for the use of human research subjects. Most of this review's references (~97%) came from a PubMed search that spanned from 1997 to 2023. Search terms included "sarcopenia" OR "muscle wasting" OR "geriatrics"; OR "ageing"; and AND "diet" OR "exercise". In addition, papers relevant or supportive of the topic as well as those considered seminal were included in the review. Over 96% of the references were peer-reviewed articles.

Low Muscle Mass Is Associated with Poorer Glycemic Control and Higher Oxidative Stress in Older Patients with Type 2 Diabetes

Body composition changes that occur during aging, such as loss of lean mass, are unfavorable at metabolic level and they can explain, in part, the appearance of certain age-associated diseases such as type 2 diabetes (T2D). Separately, T2D is associated with an increase in oxidative stress (OS) which negatively affects skeletal muscle. Our aim was to study the differences in clinical and nutritional parameters, disease control, and OS in a cohort of older patients with T2D classified according to the amount of lean mass they had. We included 100 adults older than 65 years with T2D. We found that women with low fat-free mass and muscle mass have worse T2D metabolic control. Moreover, the patients with a low percentile of muscle mass present a high value of OS. The study shows that the presence of low lean mass (LM) in the geriatric population diagnosed with T2D is associated with poorer glycemic control and greater OS.

Association between physical activity and bone mineral density in postmenopausal women: a cross-sectional study from the NHANES 2007-2018

BACKGROUND

Physical activity (PA) is generally encouraged for the treatment of osteoporosis. However, epidemiological statistics on the level of physical activity required for bone health are scarce. The purpose of this research was to analyze the association between PA and total spine bone mineral density (BMD) in postmenopausal women.

METHODS

The research study included postmenopausal women aged ≥ 50 from the National Health and Nutrition Examination Survey. The metabolic equivalent (MET), weekly frequency, and duration of each activity were used to calculate PA. Furthermore, the correlations between BMD and PA were investigated by multivariable weighted logistic regression.

RESULTS

Eventually, 1681 postmenopausal women were included, with a weighted mean age of 62.27 ± 8.18 years. This study found that performing ≥ 38MET-h/wk was linked to a lower risk of osteoporosis after controlling for several covariates. Furthermore, the subgroup analysis revealed that the connection between total spine BMD and moderate-to-vigorous PA was more obvious among postmenopausal women aged < 65 years or individuals with normal BMI (< 25 kg/m²).

CONCLUSION

Physical activity ranging from moderate to vigorous was linked to higher total spine BMD in postmenopausal women.

Possible-sarcopenic screening with disturbed plasma amino acid profile in the elderly

BACKGROUND

The mass and strength of skeletal muscle decline with age, leading to its progressive dysfunction. High-throughput metabolite profiling provides the opportunity to reveal metabolic mechanisms and the identification of biomarkers. However, the role of amino acid metabolism in possible sarcopenia remains unclear.

OBJECTIVES

The aim of this study included exploring variations in plasma amino acid concentrations in elderly individuals who have possible sarcopenia and further attempting to characterize a distinctive plasma amino acid profile through targeted metabolomics.

METHODS

A cross-sectional, correlational research design was used for this study. Thirty possible-sarcopenic elderly participants were recruited (n = 30), as determined by the Asian Working Group for Sarcopenia (AWGS). Meanwhile, a reference group of non-sarcopenic (sex-, age-, and Appendicular Skeletal muscle Mass Index (ASMI)-matched non-sarcopenic controls, n = 36) individuals was included to compare the potential differences in metabolic fingerprint of the plasma amino acids associated with sarcopenia. Both groups were conducted the body composition analysis, physical function examination, and plasma amino acid-targeted metabolomics. The amino acids in plasma were measured using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS). Also, orthogonal partial least-squares-discriminant analysis (OPLS-DA) was applied to characterize the plasma amino acid profile.

RESULTS

With respect to Handgrip Strength (HGS), the Five-Repetition Chair Stand Test (CS-5), the Six-Minute Walking Test (6MWT), the arm curl, the 30 s-Chair Stand Test (CST), the 2-Minute Step Test (2MST), the Timed Up-and-Go Test (TUGT), there was a decline in skeletal muscle function in the possible-sarcopenic group compared to the non-sarcopenic group. The mean plasma concentrations of arginine, asparagine, phenylalanine, serine, lysine, glutamine, and threonine were significantly lower in the possible sarcopenia group, whereas cirulline, proline, serine, and glutamic acid concentrations were higher. According to the multi-analysis, glutamine, serine, lysine, threonine, and proline were determined as the potential markers that indicated possible sarcopenia.

CONCLUSIONS

The findings characterize significantly altered plasma amino acid metabolisms in the elderly with possible sarcopenia, which aids to screening people who are at a high risk of developing condition, and motivating to design new preventive and therapeutic approaches.

Effectiveness of Home-Based Exercise and Nutrition Programs for Senior Adults on Muscle Outcomes: A Scoping Review

This scoping review investigates the volume of evidence for home-based exercise and nutrition programs and their effect on muscle quality among senior adults to inform implementation and future research. It aims to answer the research question: What are the evidence, challenges, and needs for research regarding a home-based exercise and nutrition intervention program to improve muscle outcomes in senior adults? This scoping review was conducted following the PRISMA extension for Scoping Review. The following databases were searched: PubMed, Scopus, MEDLINE, CINAHL, EMBASE, and the Cochrane Library. Applied filters were used to help condense the research articles. A total of 13 studies met the inclusion criteria for this scoping review. Most exercise interventions were either resistance or multi-component exercise programs. The nature of the nutrition intervention varied between different supplements, foods, education, or counseling. Muscle outcomes included muscle mass in nine studies, muscle function in all the studies, muscle strength in ten studies, and biochemical analyses in two studies. Two studies found improvements in muscle mass; two studies revealed improvements in all their muscle function tests; and three studies revealed improvements in muscle strength. Muscle biopsy in a study revealed enhanced muscle fibers, but both studies did not reveal any biomarker improvements. The scoping review findings revealed mixed results on the effectiveness of a home-based exercise and nutrition program. However, the current evidence does have many gaps to address before recommending this form of intervention for senior adults as an effective way to prevent and manage sarcopenia. Since this review identified multiple knowledge gaps, strengths, and limitations in this growing field, it can be a starting point to help build future study designs and interventions in this population.

Possible sarcopenia and risk of new-onset type 2 diabetes mellitus in older adults in China: a 7-year longitudinal cohort study

BACKGROUND

Previous studies have shown that type 2 diabetes mellitus (T2DM) can cause sarcopenia; however, these conditions may have a bidirectional association. This study aimed to explore the longitudinal association between possible sarcopenia and new-onset T2DM.

METHODS

We conducted a population-based cohort study using nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS). This study included participants aged ≥ 60 years who were free of diabetes during the baseline survey of CHARLS (2011 to 2012) and were followed up until 2018. Possible sarcopenia status was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Cox proportional hazards regression models were used to evaluate the effect of possible sarcopenia on new-onset T2DM.

RESULTS

In total, 3,707 individuals were enrolled in this study, with a median age of 66 years; the prevalence of possible sarcopenia was 45.1%. During the 7-year follow-up, 575 cases (15.5%) of incident diabetes were identified. Participants with possible sarcopenia were more likely to have new-onset T2DM than those without possible sarcopenia (hazard ratio: 1.27, 95% confidence interval: 1.07-1.50; p = 0.006). In subgroup analysis, we found a significant association between possible sarcopenia and T2DM in individuals aged < 75 years or with a BMI < 24 kg/m². However, this association was not significant in individuals aged ≥ 75 years or with a BMI ≥ 24 kg/m².

CONCLUSIONS

Possible sarcopenia is associated with an increased risk of new-onset T2DM in older adults, especially in individuals who are not overweight and aged 75 years or younger.

Sarcopenia as a Risk Factor for Complications Following Pedicle Subtraction Osteotomy

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

The objective was to determine if sarcopenia is an independent risk factor for complications in adult spinal deformity (ASD) patients undergoing pedicle subtraction osteotomy (PSO) and define categories of complication risk by sarcopenia severity.

SUMMARY OF BACKGROUND DATA

Sarcopenia is linked to morbidity and mortality in several orthopedic procedures. Data concerning sarcopenia in ASD surgery is limited, particularly with respect to complex techniques performed such as PSO. With the high surgical burden of PSOs, appropriate patient selection is critical for minimizing complications.

METHODS

We identified 73 ASD patients with lumbar CT/MRI scans who underwent PSO with spinal fusion ≥5 levels at a tertiary care center from 2005 to 2014. Sarcopenia was assessed by the psoas-lumbar vertebral index (PLVI). Using stratum-specific likelihood ratio analysis, patients were separated into 3 sarcopenia groups by complication risk. The primary outcome measure was any 2-year complication. Secondary outcome measures included intraoperative blood loss and length of stay.

RESULTS

The mean PLVI was 0.84±0.28, with 47% of patients having complications. Patients with a complication had a 27% lower PLVI on average than those without complications (0.76 vs. 0.91, P=0.021). Stratum-specific likelihood ratio analysis produced 3 complication categories: 32% complication rate for PLVI ≥ 0.81; 61% for PLVI 0.60-0.80; and 69% for PLVI < 0.60. Relative to patients with PLVI ≥ 0.81, those with PLVI 0.60-0.80 and PLVI < 0.60 had 3.2× and 4.3× greater odds of developing a complication (P<0.05). For individual complications, patients with PLVI < 1.0 had a significantly higher risk of proximal junctional kyphosis (34% vs. 0%, P=0.022), while patients with PLVI < 0.8 had a significantly higher risk of wound infection (12% vs. 0%, P=0.028) and dural tear (14% vs. 0%, P=0.019). There were no significant associations between sarcopenia, intraoperative blood loss, and length of stay.

CONCLUSIONS

The increasing severity of sarcopenia is associated with a significantly and incrementally increased risk of complications following ASD surgery that require PSO.

LEVEL OF EVIDENCE

Level III.

Combinatory Effects of Training and Nutritive Administration of Carbohydrates and Protein via Food on Strength in Postmenopausal Women, and Old Men and Women

The age-related loss of muscle mass promotes many impairments. Training and protein supplementation are suggested to prevent muscle wasting, but recommendations for all populations are not based on scientific evidence. This study combines protein/carbohydrate supplementation (PCS) and training for seniors and postmenopausal women. Project A: 51 postmenopausal women (PMW, 57.3 ± 3.0 years old) underwent health-oriented training (12 weeks, moderate-strength training + moderate-endurance training). The intervention group (IG) additionally received 110 g sour milk cheese (SMC) and toast. Project B: 25 women and 6 men (65.9 ± 4.9 years old) performed intense sling training (12 weeks). The IG additionally received 110 g SMC, toast, and buttermilk. Strength was tested before and after in both studies. Project A: there was significant increase in strength, no additional effect of PCS, and a reduction in body fat in the controls. Project B: there was significant increase in strength, significant additional effects of PCS for trunk strength, and a significant reduction in body weight. Combining training and PCS may counteract strength loss. Combined endurance/resistance training is recommended to PMW for whom the benefits of PCS are restricted. Aged subjects may benefit from PCS when training intensely, but these benefits may be strongly individual.

A systematic review of sarcopenia prevalence and associated factors in people living with human immunodeficiency virus

People living with human immunodeficiency virus (HIV) (PLWH) appear to be at an increased risk of sarcopenia, which can have a devastating effect on their life due to consequences such as physical disability, poor quality of life, and finally death. This systematic review examined sarcopenia prevalence and its associated factors in PLWH. A systematic search was conducted using the keywords in the online databases including Scopus, PubMed, Web of Science, Embase and Cochrane databases from the dates of inception up to May 2022. The retrieved articles underwent a two-step title/abstract and full-text review process, and the eligible papers were selected and included in the qualitative synthesis. Data relating to the study population, purpose of study, gender, age, race, body mass index, medical history, paraclinical results and antiretroviral therapy as associated factors of sarcopenia were extracted. In addition, the prevalence of sarcopenia in PLWH and its promoting and reducing factors were also extracted. We reviewed the 14 related studies for identifying of sarcopenia prevalence and its associated factors in PLWH. The total number of PLWH in all the reviewed studies was 2592. There was no criterion for the minimum number of people with HIV and the lowest number of PLWH was 27, and the highest number was 860. Some studies reported a significantly higher prevalence of sarcopenia in HIV-infected individuals compared with HIV-negative controls as follows: 24.2-6.7%, 15-4% and 10-6%, respectively. We showed that, age (30-50 years), being female, >5 years post-HIV diagnosis, multiple vertebral fractures, cocaine/heroin use and lower gamma-glutamyl transferase level were the main promoting factors of sarcopenia. Higher educational level, employment, physical exercise, calf circumference >31 cm, and gait speed >0.8 m/s were also factors to reduce sarcopenia. Sarcopenia prevalence in PLWH is higher than HIV-negative population. Given the importance and prevalence of sarcopenia among PLWH and its associated consequences (i.e., mortality and disability), determining its risk factors is of great importance.

Leucine Intake and Risk of Impaired Physical Function and Frailty in Older Adults

BACKGROUND

Leucine is suggested to play a central role in age-related physical decline, but the effect of dietary leucine intake on physical functioning is uncertain. We examined the prospective association between dietary leucine intake and impaired lower-extremity function (ILEF) and frailty in older adults.

METHODS

We used data from 2 956 adults aged ≥60 and older from the Seniors-ENRICA cohort. At baseline (2008-2010) and in 2012, dietary information was obtained with a validated computerized face-to-face diet history, from which energy-adjusted cumulative leucine intake per body weight was calculated. Participants were followed up through 2017 to assess incident ILEF, ascertained with the Short Physical Performance Battery, and incident frailty, according to the Fried phenotype criteria. Statistical analysis was performed with Cox models adjusted for the main potential confounders.

RESULTS

During follow-up, we identified 515 incident cases of ILEF and 241 of frailty. Compared with participants in the lowest tertile of leucine intake (35.5-89.0 mg/kg/d), those in the highest tertile (107.4-372.5 mg/kg/d) had a lower risk of ILEF (fully adjusted hazard ratio [95% confidence interval]: 0.70 [0.53-0.93], p trend: .01) and of frailty (0.63 [0.41-0.96], p trend: .03]. A higher consumption of important sources of leucine in this population, including unprocessed beef, oily and white fish, and bread, were also associated with a lower risk of incident ILEF and frailty.

CONCLUSIONS

Higher leucine intake was associated with reduced risk of ILEF and frailty. Dietary leucine, obtained from foods rich in high-quality protein, could be a key nutrient to prevent age-related physical function decline in older adults.

Sarcopenia and COVID-19 Outcomes

Coronavirus disease 2019 (COVID-19) spread rapidly and became a severe global public health threat. Older adults have a high risk of COVID-19 and its associated mortality. Sarcopenia has emerged as a predictor of poor outcomes in COVID-19 patients, including lengthy hospital stays, mortality, intensive care unit admission, need for invasive mechanical ventilation, and poor rehabilitation outcomes. Chronic inflammation, immune dysfunction, respiratory muscle dysfunction, and swallowing dysfunction may underlie the association between sarcopenia and the poor outcomes of COVID-19 patients. Interleukin 6 receptor blockers (tocilizumab or sarilumab) are recommended for treating patients with severe COVID-19, and their therapeutic effects on sarcopenia are of great interest. This review aimed to analyze the current reports on the association between sarcopenia and COVID-19 and provide an update on the contribution of sarcopenia to the severity and adverse outcomes of COVID-19 and its underlying mechanisms. We also aimed to explore the different screening tools for sarcopenia concurrent with COVID-19, and advocate for early diagnosis and treatment of sarcopenia. Given that the fight against the COVID-19 pandemic may be long-term, further research into understanding the effects of sarcopenia in patients infected with the Omicron variant is necessary.

Impact of resistance exercise rehabilitation and whey protein supplementation in elderly patients with heart failure with preserved ejection fraction with sarcopenia: a study protocol for a randomised controlled trial

INTRODUCTION

Heart failure with preserved ejection fraction (HFpEF) affects more than half of the patients with heart failure. HFpEF and sarcopenia can interact with each other and contribute to reduced physiological function and increased mortality in elderly patients. Resistance training (RT) or resistance exercise rehabilitation (RER) may have benefits for elderly HFpEF patients with sarcopenia. Whey protein supplementation (WPS) may increase the effects of exercise on strength and muscle mass, in addition to promoting heart function and quality of life (QoL). However, studies are needed to evaluate effects of RER and WPS in patients with HFpEF with sarcopenia.

METHODS AND ANALYSIS

This is a prospective, randomised, controlled clinical trial in which patients with HFpEF with sarcopenia will be randomly allocated to three groups, control, RT and RT+WP. Participants in all groups will receive basic intervention including standard medicine treatment, home-based aerobic exercise and basic nutritional intervention. The RT group will undergo resistance exercise programmes, and the RT+WP group will receive daily WPS apart from resistance exercise. The study variables will be evaluated at baseline and 12 weeks. Primary outcome measure is the change of 6 min walking distance. Secondary outcomes include parameters of muscle status, cardiac function, nutritional status, QoL and major adverse cardiovascular events. The primary efficacy analysis will follow the intention-to-treat principle.

ETHICS AND DISSEMINATION

This study was approved by Ethics Committee of China-Japan Friendship Hospital for Clinical Research (No. 2022-KY-003). The results of this study will be disseminated via peer-reviewed publications and presentations at conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2200061069.

Determination of skeletal muscle mass by aspartate aminotransferase / alanine aminotransferase ratio, insulin and FSH in Chinese women with sarcopenia

BACKGROUND

Sarcopenia is an age-related skeletal muscle disorder that involves a loss of muscle mass or strength and physiological function. Skeletal muscle deteriorates in both quantity and quality. The endocrine system is an important regulator of muscle metabolism. Therefore, we aimed to explore the relationship between biochemical markers and muscle mass in sarcopenia.

METHODS

We used the AWGS 2014 as the diagnostic criteria for sarcopenia, considering both the loss in muscle mass, muscle strength and physical performance. A total of 2837 elderly female participants over 50 years of age from the West China Health and Aging Trend (WCHAT) study were included. Insulin, glucose, 25(OH)VD, procalcitonin, alanine aminotransferase, aspartate aminotransferase, total protein, prealbumin, albumin, thyroid-stimulating hormone, free triiodothyronine, free tetraiodothyronine, triglycerides, cholesterol, high-density lipoprotein, very low-density lipoprotein, cortisol, and follicle-stimulating hormone were measured. Based on the findings of univariate analysis, multivariate regression and receiver operating characteristic (ROC) curves were established.

RESULTS

Participants with sarcopenia had significantly lower free triiodothyronine, insulin, total protein, albumin, prealbumin, albumin/prealbumin ratio (A/G), alanine aminotransferase, triglycerides, and very low-density lipoprotein concentrations (P < 0.05). Compared with those without sarcopenia, those with sarcopenia had significantly higher free tetraiodothyronine, cortisol, follicle-stimulating hormone (FSH), aspartate aminotransferase/alanine aminotransferase ratio (AST/ALT), and high-density lipoprotein concentrations (P < 0.05). Insulin (OR = 0.854), FSH (OR = 1.016), and the AST/ALT ratio (OR = 1.819) were independent risk factors for low muscle mass (P < 0.001). The AUC of insulin was the highest, followed by the AST/ALT ratio and FSH (0.691, 0.671, and 0.634, respectively), and the AUC of the mixture of the above three reached 0.736.

CONCLUSION

In this cross-sectional study of elderly Chinese females aged over 50 years from the WCHAT, FSH, insulin, and AST/ALT ratio were associated with sarcopenia and risk factors for low muscle mass.

Sarcopenia in urologic oncology: Identification and strategies to improve patient outcomes

Sarcopenia is the loss of muscle mass and function related to aging, undereating, disease conditions, or inactivity. Pre-existing sarcopenia diminishes the functional reserve of patients with cancer which increases their risk for frailty, cancer cachexia, and worse outcomes from treatments. The pathogenesis of sarcopenia is multi-factorial: opening opportunities for clinicians to work across disciplines to improve patient outcomes and quality of life. The purpose of this essay is to describe sarcopenia, discuss clinical screening and assessment for sarcopenia, and highlight potential interventions to manage sarcopenia in the urologic oncology population.

Prevalence of sarcopenia was higher in women than in men: a cross-sectional study from a rural area in eastern China

Background

There were limited studies specifically evaluating whether the difference of the prevalence of sarcopenia exists in men and women in older adults from rural areas in China. The aim of this study was to compare the prevalence of sarcopenia between men and women in a rural area in eastern China and to explore the underlying causes.

Methods

This study included 1,105 participants aged 60-89 years. Muscle mass was measured by bio-electrical impedance analysis. Hand grip strength was measured by Jamar Hydraulic Hand Dynamometer. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia-2019 Consensus. Data were analyzed using log-binomial and linear regression.

Results

The prevalence of sarcopenia was 21.7% in women and 12.9% in men among the study cohort. After adjusting for age, education level, number of diseases, income level, smoking, drinking, and eating habits, proportion of people with sarcopenia was 1.49-fold greater in women than in men (PR = 1.49, 95% CI [1.01-2.26], P = 0.055).

Conclusions

The prevalence of sarcopenia in elderly women in this rural area of eastern China is higher than in men, suggesting that women in rural areas in China seem to be more vulnerable for sarcopenia, thus early screening and prevention need to be provided for them to address such gender disparity in health.

Body Mass Index Combined With Possible Sarcopenia Status Is Better Than BMI or Possible Sarcopenia Status Alone for Predicting All-Cause Mortality Among Asian Community-Dwelling Older Adults

Background

Body mass index (BMI) and sarcopenia are common indicators of nutritional status. Possible sarcopenia, defined as low muscle strength or performance, was recently introduced by the Asian Working Group for Sarcopenia (AWGS) in 2019. We investigated for association between all-cause mortality and BMI combined with possible sarcopenia severity in Asian older adults.

Methods

This study included a subpopulation (8,195 participants aged ≥60 years; male gender: 49.4%; mean age: 69.2 ± 6.8 years) from the Fourth Thai National Health Examination Survey (NHES-IV). BMI was classified using Asia-Pacific cut-offs. Possible sarcopenia was defined using quadriceps strength based on AWGS 2019 criteria, and possible sarcopenia severity was determined using study population quartile cut-offs. All-cause mortality data was derived from the national vital registry in 2020.

Results

The prevalence of underweight status and possible sarcopenia was 11.8 and 38.9%, respectively. Multivariate analysis showed underweight individuals with severe possible sarcopenia to be at highest risk for increased mortality [adjusted hazard ratio (aHR): 3.98, 95% confidence interval (CI): 2.89-5.48], and higher risk was found in men compared to women (aHR: 5.35, 95% CI: 1.19-8.97). Obese status without possible sarcopenia was an independent protective factor (aHR: 0.61, 95% CI: 0.38-0.97).

Conclusion

BMI combined with possible sarcopenia severity is a better predictor of mortality risk than either parameter alone.

Protein intake and risk of frailty among older women in the Nurses' Health Study

BACKGROUND

There is evidence that an overall healthy diet is associated with lower risk of frailty. However, the effect of diet composition, specifically the role of protein intake on frailty, is mostly unclear. The aim of this study was to evaluate the intake of protein, including total, plant, animal, and dairy protein, in relation to frailty incidence in a large cohort of older women.

METHODS

We analysed data from 85 871 women aged ≥60 participating in the Nurses' Health Study. Intake of protein was measured nine times during follow-up from 1980 until 2010. Frailty was defined as having at least three of the following five criteria from the Fatigue, Resistance, Ambulation, Illnesses and Loss of Weight (FRAIL) scale: fatigue, low strength, reduced aerobic capacity, having ≥5 illnesses, and weight loss of ≥5%. The occurrence of frailty was assessed every 4 years from 1992 up to 2014.

RESULTS

During follow-up, we identified 13 279 incident cases of frailty. Women with a higher intake of plant protein had a lower risk of developing frailty after adjustment for all relevant confounders [relative risks across quintiles of consumption: 1.00, 0.94, 0.89, 0.86, and 0.86; P-trend < 0.001]. In contrast, those with a higher intake of animal protein intake had a higher risk of frailty [relative risks across quintiles of consumption: 1.00, 0.98, 0.99, 1.00, and 1.07; P-trend 0.04]. The intake of total and dairy protein showed no significant association with frailty in the full model. Substituting 5% of energy from plant protein intake at the expense of animal protein, dairy protein, or non-dairy animal protein was associated with 38% (29%, 47%), 32% (21%, 42%), and 42% (33%, 50%) reduced risk of frailty.

CONCLUSIONS

A higher intake of plant protein, but not animal or dairy protein, was associated with a lower risk of frailty. Substitution of plant protein for animal protein, especially non-dairy animal protein, was associated with lower risk of frailty.

High Intensity Interval Training: A Potential Method for Treating Sarcopenia

Sarcopenia, an age-related disease characterized by loss of muscle strength and muscle mass, has attracted the attention of medical experts due to its severe morbidity, low living quality, high expenditure of health care, and mortality. Traditionally, persistent aerobic exercise (PAE) is considered as a valid way to attenuate muscular atrophy. However, nowadays, high intensity interval training (HIIT) has emerged as a more effective and time-efficient method to replace traditional exercise modes. HIIT displays comprehensive effects on exercise capacity and skeletal muscle metabolism, and it provides a time-out for the recovery of cardiopulmonary and muscular functions without causing severe adverse effects. Studies demonstrated that compared with PAE, HIIT showed similar or even higher effects in improving muscle strength, enhancing physical performances and increasing muscle mass of elder people. Therefore, HIIT might become a promising way to cope with the age-related loss of muscle mass and muscle function. However, it is worth mentioning that no study of HIIT was conducted directly on sarcopenia patients, which is attributed to the suspicious of safety and validity. In this review, we will assess the effects of different training parameters on muscle and sarcopenia, summarize previous papers which compared the effects of HIIT and PAE in improving muscle quality and function, and evaluate the potential of HIIT to replace the status of PAE in treating old people with muscle atrophy and low modality; and point out drawbacks of temporary experiments. Our aim is to discuss the feasibility of HIIT to treat sarcopenia and provide a reference for clinical scientists who want to utilize HIIT as a new way to cope with sarcopenia.

Preliminary evidence of differential expression of myogenic and stress factors in skeletal muscle of older adults with low muscle strength

The age-related loss of muscle strength and mass, or sarcopenia, is a growing concern in the ageing population. Yet, it is not fully understood which molecular mechanisms underlie sarcopenia. Therefore, the present study compared the protein expression profile, such as catabolic, oxidative, stress-related and myogenic pathways, between older adults with preserved (8 ♀ and 5 ♂; 71.5 ±2.6 years) and low muscle strength (6 ♀ and 5 ♂; 78.0±5.0 years). Low muscle strength was defined as chair stand test time >15 seconds and/or handgrip strength <16kg (women) or <27kg (men) according the EWGSOP2 criteria. Catabolic signaling (i.e. FOXO1/3a, MuRF1, MAFbx, LC3b, Atg5, p62) was not differentially expressed between both groups, whereas the mitochondrial marker COX-IV, but not PGC1α and citrate synthase, was lower in the low muscle strength group. Stress factors CHOP and p-ERK1/2 were higher (~1.5-fold) in older adults with low muscle strength. Surprisingly, the inflammatory marker p-p65NF-κB was ~7-fold higher in older adults with preserved muscle strength. Finally, expression of myogenic factors (i.e. Pax7, MyoD, desmin; ~2-fold) was higher in adults with low muscle strength. To conclude, whereas the increased stress factors might reflect the age-related deterioration of tissue homeostasis, e.g. due to misfolded proteins (CHOP), upregulation of myogenic markers in the low strength group might be an attempt to compensate for the gradual loss in muscle quantity and quality. These data might provide valuable insights in the processes that underlie sarcopenia.

Relationship Between Sarcopenia and Cardiovascular Diseases in the Elderly: An Overview

With the advent of population aging, aging-related diseases have become a challenge for governments worldwide. Sarcopenia has defined as a clinical syndrome associated with age-related loss such as skeletal muscle mass, strength, function, and physical performance. It is commonly seen in elderly patients with chronic diseases. Changes in lean mass are common critical determinants in the pathophysiology and progression of cardiovascular diseases (CVDs). Sarcopenia may be one of the most important causes of poor physical function and decreased cardiopulmonary function in elderly patients with CVDs. Sarcopenia may induce CVDs through common pathogenic pathways such as malnutrition, physical inactivity, insulin resistance, inflammation; these mechanisms interact. In this study, we aimed to investigate the relationship between sarcopenia and CVDs in the elderly. Further research is urgently needed to understand better the relationship, pathophysiology, clinical presentation, diagnostic criteria, and mechanisms of sarcopenia and CVDs, which may shed light on potential interventions to improve clinical outcomes and provide greater insight into the disorders above.

Toward the recognition and management of sarcopenia in routine clinical care

Sarcopenia, the age-associated decline in skeletal muscle mass and function, is a major cause of functional decline and mortality in older adults. Despite its importance, sarcopenia often remains unrecognized and inadequately managed in routine clinical care. A major hinderance to its clinical integration is the variation in diagnostic tools for sarcopenia. Diagnostic tools include those of the European Working Group on Sarcopenia in Older People (versions 1 and 2), those of the Asian Working Group for Sarcopenia (versions 1 and 2), and that of the Sarcopenia Definition and Outcomes Consortium. The management decision process of sarcopenia warrants an evaluation of risk factors such as a sedentary lifestyle, inadequate exercise, poor nutritional intake, smoking, depression and living circumstances. Herein, we provide an evidence-based update of the prevention and management of sarcopenia and propose practical information to facilitate the disease's adoption into routine care.

Myostatin and Follistatin-New Kids on the Block in the Diagnosis of Sarcopenia in IBD and Possible Therapeutic Implications

Sarcopenia, which is a decrease in muscle strength and quality of muscle tissue, is a common disorder among patients suffering from inflammatory bowel disease. This particular group of patients often presents with malnutrition and shows low physical activity, which increases the risk of sarcopenia. Another important factor in the development of sarcopenia is an imbalanced ratio of myostatin and follistatin, which may stem from inflammation as well as genetic factors. Currently, research in this area continues, and is aimed at identifying an effective medication for the treatment of this condition. Additionally, we still have no sarcopenia markers that can be used for diagnosis. In this paper, we address the role of myostatin and follistatin as potential markers in the diagnosis of sarcopenia in patients with Crohn’s disease and ulcerative colitis, particularly in view of the genetic and biological aspects. We also present data on new perspectives in the pharmacotherapy of sarcopenia (i.e., myostatin inhibitors and gene therapy). Nevertheless, knowledge is still scarce about the roles of follistatin and myostatin in sarcopenia development among patients suffering from inflammatory bowel disease, which warrants further study.

Anti-Inflammatory Effect of Muscle-Derived Interleukin-6 and Its Involvement in Lipid Metabolism

Interleukin (IL)-6 has been studied since its discovery for its role in health and diseases. It is one of the most important pro-inflammatory cytokines. IL-6 was reported as an exacerbating factor in coronavirus disease. In recent years, it has become clear that the function of muscle-derived IL-6 is different from what has been reported so far. Exercise is accompanied by skeletal muscle contraction, during which, several bioactive substances, collectively named myokines, are secreted from the muscles. Many reports have shown that IL-6 is the most abundant myokine. Interestingly, it was indicated that IL-6 plays opposing roles as a myokine and as a pro-inflammatory cytokine. In this review, we discuss why IL-6 has different functions, the signaling mode of hyper-IL-6 via soluble IL-6 receptor (sIL-6R), and the involvement of soluble glycoprotein 130 in the suppressive effect of hyper-IL-6. Furthermore, the involvement of a disintegrin and metalloprotease family molecules in the secretion of sIL-6R is described. One of the functions of muscle-derived IL-6 is lipid metabolism in the liver. However, the differences between the functions of IL-6 as a pro-inflammatory cytokine and the functions of muscle-derived IL-6 are unclear. Although the involvement of myokines in lipid metabolism in adipocytes was previously discussed, little is known about the direct relationship between nonalcoholic fatty liver disease and muscle-derived IL-6. This review is the first to discuss the relationship between the function of IL-6 in diseases and the function of muscle-derived IL-6, focusing on IL-6 signaling and lipid metabolism in the liver.

Low urine pH is a risk factor for low muscle mass: A new way to predict sarcopenia

AIMS

Sarcopenia, one of the primary diseases of the older adult population, is a condition characterized by loss of skeletal muscle mass, strength and functionality. Due to its considerable economic impact, preventive interventions for sarcopenia play an important role in the older adult population. Urine includes many indicators of physiology and pathophysiology. Urine analysis is used to diagnose many different diseases. The goal of this cohort study was to examine the relationship between urine pH level and skeletal muscle mass.

METHODS

This community-based cross-sectional study was carried out among 9712 Taiwanese individuals (4992 men and 4720 women). We used urine pH as an independent variable and skeletal muscle mass as a dependent variable. Bioelectric impedance analysis was used to measure the percentage of skeletal muscle mass (PSMM). We collected first fasting morning urine samples after overnight fasting, and urine pH was measured with a dipstick. In the by-sex and by-obesity analyses, we stratified the sample into two subgroups and a linear regression model was used for covariate adjustment.

RESULTS

In the fully adjusted model, all-subject analysis showed a statistically significant association between urine pH and the PSMM with a β coefficient of 0.820 (95% CI 0.615-1.025; P < 0.001). Additionally, by-sex analysis showed that urine pH was related to the PSMM in both sexes, with β coefficients of 0.261 (95% CI 0.006-0.516; P = 0.045) in men and 0.179 (95% CI 0.029-0.328; P = 0.019) in women. By-obesity status analysis showed that urine pH was related to the PSMM in the body mass index <27 group with a β coefficient of 0.284 (95% CI 0.101-0.466; P = 0.002) after full adjustment. However, for the body mass index ≥27 group, there was no significant relationship between urine pH and the PSMM (P > 0.05).

CONCLUSION

The results showed the impacts of urine pH levels on skeletal muscle mass in both sexes and non-obese populations. Due to its easily accessible and economical characteristics, urine analysis is a convenient way to approach patients with low skeletal muscle mass and predict sarcopenia. Geriatr Gerontol Int 2021; 21: 944-949.

Skeletal muscle atrophy: From mechanisms to treatments

Skeletal muscle is a crucial tissue for movement, gestural assistance, metabolic homeostasis, and thermogenesis. It makes up approximately 40% of the total body weight and 50% of total protein. However, several pathological abnormalities (e.g., chronic diseases, cancer, long-term infection, aging) can induce an imbalance in skeletal muscle protein synthesis and degradation, which triggers muscle wasting and even leads to atrophy. Skeletal muscle atrophy is characterized by weakening, shrinking, and decreasing muscle mass and fiber cross-sectional area at the histological level. It manifests as a reduction in force production, easy fatigue and decreased exercise capability, along with a lower quality of life. Mechanistically, there are several pathophysiological processes involved in skeletal muscle atrophy, including oxidative stress and inflammation, which then activate signal transduction, such as the ubiquitin proteasome system, autophagy lysosome system, and mTOR. Considering the great economic and social burden that muscle atrophy can inflict, effective prevention and treatment strategies are essential but still limited. Exercise is widely acknowledged as the most effective therapy for skeletal muscle atrophy; unfortunately, it is not applicable for all patients. Several active substances for skeletal muscle atrophy have been discovered and evaluated in clinical trials, however, they have not been marketed to date. Knowledge is being gained on the underlying mechanisms, highlighting more promising treatment strategies in the future. In this paper, the mechanisms and treatment strategies for skeletal muscle atrophy are briefly reviewed.

Functionality of Bread and Beverage Added with Brosimum alicastrum Sw. Seed Flour on the Nutritional and Health Status of the Elderly

Physiological changes in elderly individuals (EI) can contribute to nutritional deterioration and comorbidities that reduce their quality of life. Factors such as diet can modulate some of these effects. The aim was to evaluate the functionality of foods added with Brosimum alicastrum Sw. seed flour in EI. EI (n = 23) living in nursing home conditions agreed to participate. A control stage was carried out (30 days) and subsequently, an intervention stage (30 days) was realized in which a muffin and a beverage, designed for EI, were added to the participants’ their usual diet. In both stages, anthropometric parameters, body composition, nutritional status, dietary intake, sarcopenic status, cognitive and affective states, biometric parameters, and total phenolic compounds (TPC), and antioxidant capacity in foods and plasma of EI were determined. The results showed that the consumption of the foods improved the energy intake and preserved the muscle reserves of the EI. The EI gained body weight (+1.1 kg), increased their protein (+18.6 g/day; 1.5 g/kg BW/day), dietary fiber (+13.4 g/day), iron (+4.4 mg/day), zinc (+1.8 mg/day), folic acid (+83.4 µg/day) consumption while reducing their cholesterol (−66 mg/day) and sodium (−319.5 mg/day) consumption. LDL-C lipoproteins reduced (14.8%) and urea (33.1%) and BUN (33.3%) increased. The TPC increased (7.8%) in the plasma, particularly in women (10.7%). The foods improve the EI nutritional status, and this has a cardiovascular protective effect that can benefit the health of the EI.

Low Protein Intakes and Poor Diet Quality Associate with Functional Limitations in US Adults with Diabetes: A 2005-2016 NHANES Analysis

Type 2 diabetes is associated with an increased risk for sarcopenia. Moreover, sarcopenia correlates with increased risk for falls, fractures, and mortality. This study aimed to explore relationships among nutrient intakes, diet quality, and functional limitations in a sample of adults across levels of glycemic control. Data were examined from 23,487 non-institutionalized adults, 31 years and older, from the 2005-2016 National Health and Nutrition Examination Survey. Hemoglobin A1c (%) was used to classify level of glycemic control: non-diabetes (<5.7%); pre-diabetes (5.7-6.4%); diabetes (≥6.5%). Dietary data were collected from a single 24-h dietary recall. Participants were categorized as meeting or below the protein recommendation of 0.8 g/kg of body weight. Physical functioning was assessed across 19-discrete physical tasks. Adults below the protein recommendation consumed significantly more carbohydrate and had lower diet quality across all glycemic groups compared to those who met the protein recommendation (p < 0.001). Adults with diabetes who did not meet protein recommendations had significantly poorer diet quality and significantly higher mean number of functional limitations. A greater percent of adults with diabetes who did not meet the protein recommendation reported being physically limited for most activities, with more than half (52%) reporting limitations for stooping, crouching, and kneeling. This study underscores the potential for physical limitations associated with low protein intakes, especially in adults with diabetes. In the longer term, low protein intakes may result in increased risk of muscle loss, as protein intake is a critical nutritional factor for prevention of sarcopenia, functional limitations, and falls.

Effect of Home-Based Exercise Program on Physical Function and Balance in Older Adults With Sarcopenia: A Multicenter Randomized Controlled Study

In the prospective, randomized, controlled multicenter study, 100 patients who were clinically diagnosed with sarcopenia were assigned to either a home-based exercise group or a control group. The home-based training program included exercises with gradually increasing intensity comprising posture, stretching and upper- and lower-extremity muscle-strengthening exercises, balance and coordination exercises, and gait training. Before and 3 months after the exercise program, all the patients were evaluated. The 6-min walking test and Berg Balance Scale scores increased significantly after 3 months in the home-based exercise group compared with the controls. There was also a significant decrease in timed up and go test scores and a significant improvement in quality of life in the exercise group compared with the control group. Our findings indicated that a home-based exercise program can have a positive effect on physical function, balance, and quality of life in patients with sarcopenia.