Functional Measures of Sarcopenia: Prevalence, and Associations with Functional Disability in 10,892 Adults Aged 65 Years and Over from Six Lower- and Middle-Income Countries

Pleiotropic effects on Sarcopenia subphenotypes point to potential molecular markers for the disease

Sarcopenia is a progressive age-related muscle disease characterized by low muscle strength, quantity and quality, and low physical performance. The clinical overlap between these subphenotypes (reduction in muscle strength, quantity and quality, and physical performance) was evidenced, but the genetic overlap is still poorly investigated. Herein, we investigated whether there is a genetic overlap amongst sarcopenia subphenotypes in the search for more effective molecular markers for this disease. For that, a Bioinformatics approach was used to identify and characterize pleiotropic effects at the genome, loci and gene levels using Genome-wide association study results. As a result, a high genetic correlation was identified between gait speed and muscle strength (rG=0.5358, p=3.39 × 10-8). Using a Pleiotropy-informed conditional and conjunctional false discovery rate method we identified two pleiotropic loci for muscle strength and gait speed, one of them was nearby the gene PHACTR1. Moreover, 11 pleiotropic loci and 25 genes were identified for muscle mass and muscle strength. Lastly, using a gene-based GWAS approach three candidate genes were identified in the overlap of the three Sarcopenia subphenotypes: FTO, RPS10 and CALCR. The current study provides evidence of genetic overlap and pleiotropy among sarcopenia subphenotypes and highlights novel candidate genes and molecular markers associated with the risk of sarcopenia.

The Effect of Family Wealth on Physical Function Among Older Adults in Mpumalanga, South Africa: A Causal Network Analysis

Objectives: The aging of the South African population could have profound implications for the independence and overall quality of life of older adults as life expectancy increases. While there is evidence that lifetime socio-economic status shapes risks for later function and disability, it is unclear whether, and how, the wealth of family members shapes these outcomes. We investigated the relationship between outcomes activities of daily living (ADL), grip strength, and gait speed, and the household wealth of non-coresident family members. Methods: Using data from Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) and the Agincourt Health and Demographic Surveillance System (AHDSS), we examined the relationship between physical function and household and family wealth in the 13 preceding years. HAALSI is a cohort of 5,059 adults who were 40 years or older at baseline in 2014. Using auto-g-computation-a recently proposed statistical approach to quantify causal effects in the context of a network of interconnected units-we estimated the effect of own and family wealth on the outcomes of interest. Results: We found no evidence of effects of family wealth on physical function and disability. Conclusion: Further research is needed to assess the effect of family wealth in early life on physical function and disability outcomes.

Is age-related sarcopenia a real concern for my developing country?

Ageing is a distinctive feature of living organisms. With the modernization of human societies, including the development of science, technology and education, expected life expectancy at birth is being extended. This allows novel health-related conditions to gain particular interest amongst the field experts. Along comes sarcopenia, an age-related condition of global proportions that effects all populations, societies and countries. Several international working groups have been trying to identify the more appropriate and applicable sarcopenia definition and diagnostic criteria to follow. Contrary to the initial muscle mass-related context, the shift of attention to muscle strength by the revised European Working Group in Sarcopenia for Older People (EWGSOP2) was ground-breaking and potentially game-changing. The suggested diagnostic algorithm by the EWGSOP2 for case finding, diagnosing and quantifying the severity of cases further facilitated the applicability on clinical practices. Since being directly related to the ageing process, sarcopenia presents an issue of growing concern particularly within the high-income and developed world regions that are generally characterized with an increased life expectancy. In contrast, the developing world and their generally lower life expectancy do not always have sarcopenia amongst the top targeted health-related concerns. In such cases, the expected life expectancy and the populations' quality of life do not necessarily present an issue of major interest. Other serious medical concerns of acute state often eclipse the need for long-term health-related investments, shifting the interest towards only direct interventions and short-term planning. In conclusion, the emerging of sarcopenia as a serious age-related concern is finding care providers and healthcare systems from lower and middle-income countries (LMICs) unprepared. For the time being, it needs to be introduced and promoted in the developing world as a condition with direct life-threatening implications. Simple and creative forms of approach should be ideated and implemented in both scientific and clinical contexts (by researchers and care providers, respectively). The best practice to address this situation would be by empowering intradisciplinary and interdisciplinary collaborations, as well as facilitating interconnections between researches, healthcare practitioners and clients. This should help establish sarcopenia as a serious age-related condition that needs a multidisciplinary and multidimensional approach.

Longitudinal association of sarcopenia and mild cognitive impairment among older Mexican adults

BACKGROUND

Recent evidence from cross-sectional and longitudinal studies supports the hypothesis that sarcopenia is associated with worsening cognitive function. However, primary evidence largely comes from high-income countries, whereas in low- and middle-income countries, this association has been underexplored. This study aimed to estimate the longitudinal association between sarcopenia and mild cognitive impairment in a sample of older Mexican adults.

METHODS

Data come from the three waves of the World Health Organization (WHO) Study on Global AGEing and Adult Health (SAGE) in Mexico (2009, 2014, 2017). Four hundred ninety-six older adults, aged ≥50, were included. Sarcopenia was defined as having low muscle quantity and either/both slow gait speed and weak handgrip strength. Mild cognitive impairment was determined based on the recommendations of the National Institute on Aging-Alzheimer's Association. Cognitive function was evaluated by a composite cognitive score of five different cognitive tests: immediate and delayed recall, forward and backward digit span and semantic verbal fluency. Three-level mixed-effects models (logistic and linear) were used to estimate the longitudinal associations between sarcopenia, mild cognitive impairment and cognitive function.

RESULTS

The prevalence of mild cognitive impairment (8.9%, 12.9%, 16.0%) and sarcopenia (10.5%, 20.7%, 23.3%) showed a significant temporal increase for Waves 1, 2 and 3 (P-value < 0.01, respectively). The presence of sarcopenia was significantly associated with mild cognitive impairment (OR = 1.74; CI95% 1.02, 2.96; P = 0.04) and worse cognitive function (β = -0.57; CI95% -0.93, -0.21; P < 0.01). We observed significant associations between sarcopenia and immediate verbal recall (β = -0.14; CI95% -0.28, -0.01; P = 0.04), delayed verbal recall (β = -0.12; CI95% -0.23, -0.01; P = 0.03) and semantic verbal fluency (β = -0.17; CI95% -0.28, -0.05; P = 0.01). The prevalence of mild cognitive impairment increased at an annual rate of 0.8% for non-sarcopenic older adults, but nearly 1.5% for sarcopenic adults.

CONCLUSIONS

Significant longitudinal associations were observed between sarcopenia, mild cognitive impairment and cognitive function among older Mexican adults. Public health strategies, including policy research and clinical interventions, must be implemented in low- and middle-income countries in order to reduce or delay the onset of sarcopenia and thus improve population-level cognitive health among older adults.

Associations between socioeconomic status and obesity, sarcopenia, and sarcopenic obesity in community-dwelling older adults: The Tasmanian Older Adult Cohort Study

BACKGROUND

Social disadvantage may contribute to increased prevalence of sarcopenia and obesity. This study investigated if socioeconomic factors are associated with obesity, sarcopenia, or sarcopenic obesity (SO), in community-dwelling older adults.

METHODS

This was a cross-sectional analysis of data from the Tasmanian Older Adult Cohort study. Obesity was defined by body fat percentage (Men: ≥25%; Women: ≥35%) and sarcopenia was defined as the lowest 20% of sex-specific appendicular lean mass (ALM)/height (m²) and handgrip strength. Socioeconomic factors investigated were education (tertiary degree, secondary or no secondary school), occupation (high skilled white-collar, low skilled white-collar, or blue-collar) and residential area (advantaged or disadvantaged area). Multinomial logistic regression analyses yielding odds ratios (95% confidence intervals) were performed and adjusted for potential confounders. Mediation analysis was performed.

RESULTS

1099 older adults (63.0 ± 7.5 years; 51.1% women) participated. Older adults with a tertiary degree were significantly less likely to have obesity (0.68; 0.47, 0.98) and SO (0.48; 0.24, 0.94) compared with those who had no secondary schooling. No associations were found for occupation. Similarly, older adults living in advantaged areas were significantly less likely to have obesity (0.61; 0.39, 0.95). Steps per day mediated the association between residential area and body fat percentage by 51%.

CONCLUSION

Lower educational attainment, but not occupation, was associated with increased likelihood for both obesity and SO in community-dwelling older adults. Low physical activity levels in disadvantaged areas substantially contributed to higher obesity prevalence in this population. Further research is necessary to confirm whether similar associations exist in populations with greater levels of social disadvantage and to design effective community-based interventions.

Sarcopenia and fall-related injury among older adults in five low- and middle-income countries

Sarcopenia is a common condition in older people and increasing evidence suggests that it can be considered as a potential risk factor for falls and fractures. However, no studies on this topic from low- and middle-income countries (LMICs) are available. Thus, we assessed this association among older adults from five LMICs (China, India, Ghana, Mexico, and Russia). Community-based, nationally representative, cross-sectional data of the Study on Global Aging and Adult Health were analyzed. Sarcopenia was defined as the presence of low skeletal muscle mass based on indirect population formula, and either slow gait or low handgrip strength. The presence of fall-related injury was ascertained through self-reported information. Multivariable logistic regression analysis and meta-analysis were conducted. The sample consisted of 13,101 individuals aged ≥65 years (mean (SD) age 72.6 (11.3) years; 45% males). The prevalence of fall-related injury was higher among those with sarcopenia than in those without this condition (e.g., Mexico 9.8% vs. 2.7%). Adjusted analyses showed that sarcopenia was associated with a 1.85 (95%CI = 1.24-2.77) times higher odds for fall-related injury, with a low level of between-country heterogeneity. Future studies of longitudinal design may shed light on whether sarcopenia in LMICs may be considered as a risk factor for falls.

Effect of long-term moderate-exercise combined with metformin-treatment on antioxidant enzymes activity and expression in the gastrocnemius of old female Wistar rats

Oxidative stress is known to be involved in the etiology of sarcopenia, a progressive loss of muscle mass and force related to elderly incapacity. A successful intervention to prevent this condition has been exercise-based therapy. Metformin (MTF), an anti-diabetic drug with pleiotropic effects, is known to retain redox homeostasis. However, the combined use of MTF with exercise has shown controversial experimental results. Our research group has shown that MTF-treatment does not limit the benefits provided by exercise, probably by inducing a hormetic response. Hence, our aim was to evaluate the effect of exercise in combination with MTF-treatment on the redox state of old female Wistar rats. Animals were divided into six groups; three groups preformed exercise on a treadmill for 5 days/week for 20 months and the other three were sedentary. Also, two groups of each, exercised and sedentary animals were treated with MTF for 6 or 12 months correspondingly, beside the untreated groups. Rats were euthanized at 24 months. Muscular functionality was analyzed as the relation between the lean mass free of bone with respect to the grip strength. Superoxide dismutase, catalase, and glutathione peroxidase content, enzymatic activity and redox state were determined in the gastrocnemius muscle. Our results showed that the exercised group treated with MTF for 12 months presented higher GSH/GSSG rate and high antioxidant scavenging power in contrast to the MTF-treatment for 6 months, where the beneficial effect was less noticeable.

Prevalence of sarcopenia in an elderly population in rural South India: a cross-sectional study

Background: Sarcopenia is a condition common in the elderly characterized by progressive and generalized loss of skeletal muscle mass and strength leading to poor quality of life. According to a working definition proposed by the European Working Group on Sarcopenia in Older People (EWGSOP), the criteria for a diagnosis of sarcopenia is based on documentation of low muscle mass with either poor muscle strength or low physical performance. The objective of the present study was to determine the prevalence of sarcopenia in the rural elderly population of South India. Methods: We conducted a cross-sectional survey of 240 elderly people, 60 years and above, 118 men and 122 women, in rural areas of Dakshina Kannada district. We measured their height, weight, gait speed (using an 8-feet walk test) and muscle strength (using a handgrip dynamometer). Appendicular skeletal mass was calculated using height and weight adjusted for sex and Asian people using the Lee formula. Results: Sarcopenia was found in 34 (14.2%) participants. Of all those having sarcopenia, 27 (79.4%) were ≤75 years, 30 (88.2%) were women, 27 (79.4%) were married, 23 (67.6%) had below poverty line status. Conclusions: The prevalence of sarcopenia found in the present study was 14.2% in an elderly population more than 60 years of age and was found to be more in women. Large-scale multi-centric community-based surveys will help determine the actual burden of sarcopenia in India.

Sarcopenia in male patients with head and neck cancer receiving chemoradiotherapy: a longitudinal pilot study

Introduction

Muscle wasting conditions such as sarcopenia may be highly prevalent in advanced head and neck cancer (HNC) patients (16-71%), with these prevalence rates substantially greater in those who have received chemo-radiotherapy (CRT). According to the updated European Working Group on Sarcopenia in Older People consensus statement, sarcopenia is defined as the age-related loss of muscle strength, muscle mass and physical performance. The high prevalence of sarcopenia in HNC patients is concerning as it has been associated with substantially increased risk of CRT toxicity, respiratory complications and early mortality. With the high prevalence of HNC and sarcopenia in India and the strong link between sarcopenia and poor HNC patient outcomes, it is important to screen for the presence of sarcopenia in Indian patients receiving CRT for HNC.

Methods

This longitudinal pilot study aimed to routinely monitor 19 men receiving CRT for their HNC for a variety of sarcopenic-related outcomes over three time points during their 7 weeks of CRT. Participants were required to be male, with a minimum age of 30 years, with a Stage III, IVa or IVb diagnosis of HNC and be currently undergoing a 7 weeks course of CRT in an oncology department. Outcomes included probable sarcopenic diagnosis were estimated by the SARC-F, handgrip strength, skeletal muscle mass was estimated by bioelectrical impedance and physical performance was assessed by the Timed Up and Go. Repeated measures ANOVA and Bonferroni post-hoc tests were used to identify significant differences at the three time points with a p < 0.05.

Results

The 19 participants in this trial at a mean age of 56.5 ± 10.2 years (range = 39-75 years), with most (n = 13, 68.4%) employed in laboring occupations. At baseline, 31.5% (n = 6) of the participants already had probable sarcopenia based on their total SARC-F score, with this increasing to 89.4% (n = 17) at the end of 7 weeks CRT. In addition, significant decreases in strength, skeletal muscle mass and Timed Up and Go performance were observed, with these declines significantly greater at 7 weeks than 3 weeks after commencing CRT.

Conclusions

Patients with HNC undergoing 7 weeks of CRT showed clinically significant increases in the incidence of probable sarcopenia based on their total SARC-F score as well as clinically significant declines in handgrip strength, skeletal muscle mass and Timed Up and Go performance. Due to the relationship between sarcopenia and a host of adverse events related to CRT in HNC patients, these results suggest that oncologists and their allied health teams should routinely monitor these patients during CRT and provide the relevant exercise therapy and nutritional support to those patients in need.