Difference in sarcopenia characteristics associated with physical activity and disability incidences in older adults

Use of electrical bioimpedance in the assessment of sarcopenia in the older aldults: A scoping review

OBJECTIVE

to map and synthesize the main evidence on the use of bioelectrical impedance (BIA) and its variables in the assessment of sarcopenia in community-dwelling older adults.

METHODS

This is a scoping review carried out by searching for articles available in four databases: PUBMED, LILACS, Web of Science and CINAHL, with the following search strategy: Body Composition AND Sarcopenia AND ″electric impedance'' OR ″bioelectrical impedance analysis'' AND Aged.

RESULTS

A total of 27,660 older adults made up the sum of the samples of the included studies. Most studies included participants of both sexes (75.6%), used the variable skeletal and/or appendicular skeletal muscle mass (ASMM) (75.6%), followed by body fat (8.1%), and phase angle (8.1%) in the assessment of the body composition of subjects with sarcopenia.

CONCLUSION

The data from this research show that ASMM and phase angle are the main variables related to sarcopenia screening in community-dwelling older adults. Whereas total extracellular water/body water is still considered a confounding variable in the screening of sarcopenia in the elderly, but it can be considered useful regarding the health conditions of the elderly in the community.

How long were older people expected to live with or without sarcopenia? Multistate modeling of a national cohort study

Objectives

Sarcopenia is well known to be associated with mortality, but there is a lack of evidence on the estimates of life expectancy (LE) for sarcopenia in China. This study aims to estimate total life expectancy (TLE) and sarcopenia-specific LE in community-dwelling older Chinese adults with and without sarcopenia.

Methods

This study included participants aged 60 years and older who enrolled in the cohort in 2011 and 2013 and at least completed one follow-up until 2015 as part of the China Health and Retirement Longitudinal Study (CHARLS). The criteria for defining sarcopenia were based on the guidelines established by the Asian Working Group on Sarcopenia in 2019. TLE and sarcopenia-specific LE were estimated for the total population and subgroups using continuous-time multistate modeling.

Results

A total of 6,029 participants (49.2% women) with an average age of 68.4 (SD: 6.56) years were included in the study. The baseline prevalence of sarcopenia and possible sarcopenia was 19.5 and 44.9%, respectively. We observed that sarcopenia stages naturally deteriorated to worse stages (including death, by 24.4%) and returned to better stages (17.1%) during a median follow-up of 3.92 years (IQR: 2.00 ~ 4.00). The average TLE at the age of 60 was 20.9 [95% CI: 20.2-21.5] years (22.1 [95% CI: 19.6-24.6] for non-sarcopenic older adults, 20.9 [95% CI: 19.5-22.3] for possible sarcopenic, and 18.7 [95% CI: 16.4-21.1] for sarcopenic). Men, former and current smokers, and those living in northwest China had less TLE. Sarcopenic older adults, those with lower education, those who are unmarried, those with agriculture hukou, and those living in rural and northwest China were expected to live fewer years with non-sarcopenia. Sarcopenic older people, men, those with agriculture hukou, and those living in rural and southwest China were expected to live more years with sarcopenia.

Discussion

The results improved our understanding of the relationship between sarcopenia and life expectancy. We suggested that targeted strategies should be considered in high-risk populations and underdeveloped regions to prevent sarcopenia and improve non-sarcopenic life years for the older population.

Fiber-Type Shifting in Sarcopenia of Old Age: Proteomic Profiling of the Contractile Apparatus of Skeletal Muscles

The progressive loss of skeletal muscle mass and concomitant reduction in contractile strength plays a central role in frailty syndrome. Age-related neuronal impairments are closely associated with sarcopenia in the elderly, which is characterized by severe muscular atrophy that can considerably lessen the overall quality of life at old age. Mass-spectrometry-based proteomic surveys of senescent human skeletal muscles, as well as animal models of sarcopenia, have decisively improved our understanding of the molecular and cellular consequences of muscular atrophy and associated fiber-type shifting during aging. This review outlines the mass spectrometric identification of proteome-wide changes in atrophying skeletal muscles, with a focus on contractile proteins as potential markers of changes in fiber-type distribution patterns. The observed trend of fast-to-slow transitions in individual human skeletal muscles during the aging process is most likely linked to a preferential susceptibility of fast-twitching muscle fibers to muscular atrophy. Studies with senescent animal models, including mostly aged rodent skeletal muscles, have confirmed fiber-type shifting. The proteomic analysis of fast versus slow isoforms of key contractile proteins, such as myosin heavy chains, myosin light chains, actins, troponins and tropomyosins, suggests them as suitable bioanalytical tools of fiber-type transitions during aging.

Estimation of Appendicular Skeletal Muscle Mass for Women Aged 60-70 Years Using a Machine Learning Approach

OBJECTIVES

This article aimed to develop and validate an anthropometric equation based on the least absolute shrinkage and selection operator (LASSO) regression, a machine learning approach, to predict appendicular skeletal muscle mass (ASM) in 60-70-year-old women.

DESIGN

A cross-sectional study.

SETTING AND PARTICIPANTS

Community-dwelling women aged 60-70 years.

METHODS

A total of 1296 community-dwelling women aged 60-70 years were randomly divided into the development or the validation group (1:1 ratio). ASM was evaluated by bioelectrical impedance analysis (BIA) as the reference. Variables including weight, height, body mass index (BMI), sitting height, waist-to-hip ratio (WHR), calf circumference (CC), and 5 summary measures of limb length were incorporated as candidate predictors. LASSO regression was used to select predictors with 10-fold cross-validation, and multiple linear regression was applied to develop the BIA-measured ASM prediction equation. Paired t test and Bland-Altman analysis were used to validate agreement.

RESULTS

Weight, WHR, CC, and sitting height were selected by LASSO regression as independent variables and the equation is ASM = 0.2308 × weight (kg) - 27.5652 × WHR + 8.0179 × CC (m) + 2.3772 × Sitting height (m) + 22.2405 (adjusted R² = 0.848, standard error of the estimate = 0.661 kg, P < .001). Bland-Altman analysis showed a high agreement between BIA-measured ASM and predicted ASM that the mean difference between the 2 methods was -0.041 kg, with the 95% limits of agreement of -1.441 to 1.359 kg.

CONCLUSIONS AND IMPLICATIONS

The equation for 60-70-year-old women could provide an available measurement of ASM for communities that cannot equip with BIA, which promotes the early screening of sarcopenia at the community level. Additionally, sitting height could predict ASM effectively, suggesting that maybe it can be used in further studies of muscle mass.

Association of sleep duration with sarcopenic obesity in multi-ethnic older adults: findings from the WCHAT Study

OBJECTIVE

Sarcopenic obesity is a prevalent geriatric syndrome, characterized by concurrence of sarcopenia and obesity. Sleep duration is linked to both obesity and sarcopenia. However, little was known regarding the association of sleep duration with sarcopenic obesity. In this study, we aimed to examine the association of sleep duration with sarcopenic obesity in multi-ethnic community-dwelling older adults.

METHODS

Sarcopenia was defined according to the criteria established by Asian Working Group for Sarcopenia (AWGS) 2019. Obesity was defined as body fat percentage above the 60th percentile specified by sex. Sarcopenic obesity was defined as concurrence of obesity and sarcopenia. Sleep duration was collected by a self-reported questionnaire and was further divided into 5 groups: "<6 h", "6-7 h", "7-8 h", "8-9 h" (reference group) and "≥9 h" (long sleep). Logistic regressions were adopted to examine the association.

RESULTS

2256 multi-ethnic adults aged 60 and over from the West China Health and Aging Trend (WCHAT) study were involved for present study. Overall, 6.25% of the participants were classified as sarcopenic obesity. In the fully adjusted model, long sleep duration (≥ 9 h) was significantly associated with sarcopenic obesity compared with reference group (OR = 1.81, 95%CI = 1.10-2.98, P = 0.019). However, in subgroup analysis, this association can only be observed in male (OR 1.98, 95% CI = 1.02-3.87, P = 0.043) not in female (OR = 1.83, 95%CI = 0.85-3.94, P = 0.118). Regarding ethnic difference, Han older adults with long sleep duration (≥ 9 h) presented increased risk of sarcopenic obesity while ethnic minorities did not.

CONCLUSION

This study disclosed that long sleep duration significantly increased the risk of sarcopenic obesity among older adults. And our findings highlight the critical role of assessing sleep duration to identify individuals at risk of sarcopenic obesity.

Differences in Health-Related Quality of Life in Older People with and without Sarcopenia Covered by Long-Term Care Insurance

Background: As a result of the increase in older people covered by long-term care insurance (LTCI), prevention of sarcopenia and maintenance and improvement of health-related quality of life (HRQOL) have become important themes. This study aimed to clarify both the differences in HRQOL in older people with and without sarcopenia covered by LTCI and the correlation between HRQOL and physical function. Methods: Participants were 101 older people with LTCI at a daycare center in Japan. We investigated clinical factors using the EuroQol five-dimension three-level questionnaire (EQ-5D-3L). Analysis was by unpaired t-test, Mann−Whitney U test, chi-square test, analysis of covariance, Pearson’s correlation coefficient, and Spearman’s rank correlation coefficient. Results: Compared to the no sarcopenia group (n = 40), the sarcopenia group (n = 24) had significantly lower body mass index, skeletal muscle mass index, gait speed, EQ-5D-3L, and adjusted EQ-5D-3L (p < 0.05). The EQ-5D-3L showed a significant correlation with handgrip strength in the sarcopenia group (p = 0.02) and significant correlations with gait speed and one-leg standing time (both, p = 0.01) in the no sarcopenia group. Conclusion: We clarified differences in HRQOL in older people with and without sarcopenia covered by LTCI. This information on the interrelationship between HRQOL and physical function may help maintain and improve HRQOL in these people.