Unfavorable body composition and quality of life among community-dwelling middle-aged and older adults: What really matters?

Muscle Mass Adjusted by Body Height is not Correlated with Mobility of Middle-Aged and Older Adults

Background

Low muscle mass and obesity are associated with mobility disability, cardiometabolic diseases, and loss of independence. Three skeletal muscle indices (SMIs) are proposed to adjust the body size of individuals. However, it is unknown which index is better correlated with mobility. Additionally, it remains unclear whether low muscle mass or abdominal obesity has a greater impact on the mobility and cardiometabolic health of older adults.

Objectives

This study explored the association between different SMIs {appendicular skeletal muscle mass [ASM] adjusted by body height [Ht], body weight [Wt], or body mass index [BMI (kg/m2)]} and mobility/cardiometabolic health. The roles of low muscle mass and abdominal obesity in the mobility and cardiometabolic health of individuals were also identified.

Methods

Four-hundred and twenty-seven community-dwelling middle-aged and older adults underwent body composition assessments [dual-energy x-ray absorptiometry and waist circumference (WC)], grip strength, and mobility (timed up-and-go test and chair stand test). Spearman's rank correlation coefficient and regression models were used to examine research questions. This study was registered in the Thai Clinical Trials Registry (registration number: TCTR20210521007).

Results

All SMIs were positively correlated with the grip strength (ASM/Ht2: r = 0.392; ASM/Wt: r = 0.439; ASM/BMI: r = 0.569). Regarding mobility, only ASM/Ht2 wasn't relevant. After adjusting for age, sex, and WC, ASM/BMI was the only SMI associated with grip strength (β = 0.274). When age and sex were controlled, WC, but not SMI, was associated with mobility and cardiometabolic health.

Conclusions

ASM/Ht2 did not correlate with mobility in middle-aged and older adults, whereas ASM/Wt and ASM/BMI did. Abdominal obesity has a greater impact on mobility and cardiometabolic health than low muscle mass in middle-aged and older adults. We recommend using ASM/BMI to identify the low muscle mass of individuals. In addition, clinicians should note the important role of abdominal obesity when considering mobility in middle-aged and older adults.

Anti-tumor necrosis factor-α is potentially better than tumor necrosis factor-α as the biomarker for sarcopenia: Results from the I-Lan longitudinal aging study

Tumor necrosis factor (TNF)-α is a proinflammatory cytokine involved in the pathogenesis of sarcopenia, but its short half-life and inconsistent reproducibility limit the potential of TNF-α to be an ideal sarcopenia biomarker. Anti-TNF-α, a natural consequent autoantibody to TNF-α, is an indicator of relatively prolonged TNF-α exposure, has more stable concentrations than TNF-α and should be a better alternative as a biomarker of sarcopenia. Data from 484 participants from the I-Lan Longitudinal Aging Study were used for this study, and sarcopenia was defined by the Asian Working Group for Sarcopenia 2019 consensus. Plasma levels of anti-TNF-α were determined by a sandwich ELISA approach, and levels of TNF-α were determined by an immunoassay. Compared to nonsarcopenic participants, 43 sarcopenic participants had higher levels of anti-TNF-α (0.73 ± 0.19 vs. 0.79 ± 0.25 OD, p = 0.045). Plasma levels of anti-TNF-α were positively correlated with TNF-α (r = 0.24, p < 0.001), and plasma levels of anti-TNF-α were positively correlated with adiposity (r = 0.16, p < 0.001) and negatively correlated with lean body mass (r = -0.14, p = 0.003). Individuals with increasing levels of anti-TNF-α had higher odds of being sarcopenic (OR 5.4, 95 % CI: 1.1-25.8, p = 0.035), and these associations were stronger among women and younger adults. An association between TNF-α and sarcopenia was noted only in middle-aged adults (OR 6.2, 95 % CI: 1.8-21.7, p = 0.004). Plasma anti-TNF-α levels were positively correlated with TNF-α and were significantly associated with sarcopenia. Anti-TNF-α may be a more appropriate biomarker than TNF-α for sarcopenia, but further investigations are needed to confirm its roles in sarcopenia diagnosis and treatment response evaluation.

Body weight influences musculoskeletal adaptation to long-term voluntary wheel running during aging in female mice

Frailty is the hallmark of aging that can be delayed with exercise. The present studies were initiated based on the hypothesis that long-term voluntary wheel running (VWR) in female mice from 12 to 18 or 22 months of age would have beneficial effects on the musculoskeletal system. Mice were separated into high (HBW) and low (LBW) body weight based on final body weights upon termination of experiments. Bone marrow fat was significantly higher in HBW than LBW under sedentary conditions, but not with VWR. HBW was more protective for soleus size and function than LBW under sedentary conditions, however VWR increased soleus size and function regardless of body weight. VWR plus HBW was more protective against muscle loss with aging. Similar effects of VWR plus HBW were observed with the extensor digitorum longus, EDL, however, LBW with VWR was beneficial in improving EDL fatigue resistance in 18 mo mice and was more beneficial with regards to muscle production of bone protective factors. VWR plus HBW maintained bone in aged animals. In summary, HBW had a more beneficial effect on muscle and bone with aging especially in combination with exercise. These effects were independent of bone marrow fat, suggesting that intrinsic musculoskeletal adaptions were responsible for these beneficial effects.

Gender difference in appendicular muscle strength: determinant of the quality of life in the older Taiwanese

Background: The loss of skeletal muscle mass by aging determines the health status and the quality of life (QoL).

Objective: To examine the relationships between appendicular muscle strength and the QoL of elderly adults in gender difference.

Methods: This was a cross-sectional study, in which 690 subjects who participated in older adults health examination in the health management center of Tri-Service General Hospital from 2018 to 2021. A structured questionnaire was used to collect basic demographic data. The 12-Item Short Form Survey (SF-12) was used to evaluate the QoL of subjects. Their grip strength and gait speed were measured, and Dual-energy X-ray absorptiometry was used to measure muscle mass and other body composition data. Multivariate regression analysis was used to examine the relationships between upper and lower limb muscle strength and the QoL of older adults.

Results: In men, legs muscle mass percentage (LegsMM%) (β = 3.67; 95% CI: 0.64–6.69; p = 0.018) and gait speed (β = 6.09; 95% CI: 3.88–8.30; p < 0.001) were positively associated with physical component summary (PCS) scores, and gait speed (β = 4.63; 95% CI: 2.66–6.60; p < 0.001) was also related to an improvement mental component summary (MCS) scores. In women, arms muscle mass percentage (ArmsMM%) (β = 6.50; 95% CI: 2.34–10.66; p = 0.002) and grip strength (β = 10.54; 95% CI: 6.27–14.81; p < 0.001) had the greatest effect on improving PCS scores, whereas grip strength (β = 7.58; 95% CI 4.00–11.17; p < 0.001) was also found to help improve MCS scores.

Conclusions: Men should focus on lower limb training, whereas females should focus on upper limb training to effectively improve their QoL. Appropriate exercise interventions should be designed for different genders for the promotion of the healthy aging policy.

Sex-different changes of body composition in aging: a systemic review

OBJECTIVE

Aging causes changes in body composition, in which differences in the distribution and amount of fat and muscle tissue affect the development of various diseases according to sex. We conducted a systemic review of the literature and examined the relationship between body composition differences and related health conditions or diseases in older men and women.

METHODS

Three different electronic databases (MEDLINE, Web of Science, and Embase) were used to find articles from 2000 until March 2022. Information on the study design characteristics, setting, measure of body composition, and health outcomes was extracted.

RESULTS

A total of 217 articles were retrieved, and 28 studies met the inclusion criteria. The included studies showed that older men have larger skeletal muscle mass (sMM) than women, while older women have larger fat mass (FM) than men. sMM has a favorable effect on physical performance, bone density, metabolism, cognitive function, and mortality in both men and women; however, the effects of sMM in women are less significant and even negligible compared to those in men. FM is significantly unfavorable for physical performance in women but sometimes favorable or unfavorable for glucose level and cognitive and lung function according to location. FM in men is usually less important for function, bone density, glucose level, and cognitive function than in women.

CONCLUSION

Changes in muscle and fat distribution according to aging and their correlation with health outcomes differ according to sex. Muscle mass may not always be favorable, and fat mass may not always be unfavorable in older adults.

The Benefits of Utilizing Total Body Composition as a Predictor of Cardiorespiratory Fitness Based on Age: A Pilot Study

Maximal oxygen consumption (VO2max) has been associated with body fat percentage (%BF) or fat free mass. However, most analyses do not consider total body composition (TBC) as defined by %BF, fat free mass index (FFMI—a height-adjusted measure of muscle mass), visceral adipose tissue, and bone mineral content (BMC). The aim of this study was to determine if TBC predicts cardiorespiratory fitness in healthy adults and if a relationship exists in young and older adults. Sixty healthy individuals (age group 1 (AG1, ≤35 years), n = 35; age group 2 (AG2, >35 years), n = 25) were screened in a cross-sectional study and retrospectively examined. All participants completed a full body DEXA scan and a standardized multistage treadmill test to determine VO2max. A multiple linear regression analysis was performed to examine the relationship between TBC and VO2max. The multiple regression model showed an overall significant effect for TBC (p < 0.001, R2 = 0.282). When analyzed by age group, the regression model of TBC was not significant in young adults (AG1, p = 0.319, R2 = 0.141), but significant in older adults (AG2, p < 0.001, R2 = 0.683). Significant predictors of VO2max in the older cohort were %BF (β = −0.748, p = 0.001) and BMC (β = 0.014, p = 0.002). Total body composition predicted VO2max in a small cohort of healthy adults. This study highlights the importance of TBC for cardiovascular health, especially in mid-to later-life individuals.

Protein-enriched diet improved muscle endurance and marginally reduced intramuscular adiposity: Results from a randomized controlled trial among middle-aged and older adults

BACKGROUND

Maintaining sufficient dietary protein intake is important for nutritional status, muscle mass, and healthy aging, but the clinical effects of high protein diet remained controversial..

METHODS

This 12-week randomized controlled trial enrolled community-dwelling middle-aged and older adults to evaluate clinical effects of daily diet with different protein density.. All participants received 10 frozen meals per week for 12 weeks containing either 15% daily calorie of protein (regular-protein group, RPG), or 25% daily calorie of protein (high-protein group, HPG). Bioimpedance analysis was used to assess body composition, and the magnetic resonance imaging on both mid-thighs was performed to measure muscle mass and the intramuscular adiposity.

RESULTS

This trial enrolled 70 participants, and data of 52 participants (mean age: 53.7 ± 8.3 years, 53.8% male; 25 in RPG and 27 in HPG) were available for analysis. Baseline demographic characteristics, functional assessment, body composition and muscle parameters, and laboratory data were similar between groups. During the study period, participants of both groups significantly reduced body weight, body mass index, total body fat percentage, and handgrip strength, but not in the relative appendicular muscle mass). Compared to participants of RPG, HPG participants showed significant improvement in 6-minute walking distance, increased high-sensitivity C-reactive protein and marginal reduction in intramuscular adiposity than RPG participants.

CONCLUSIONS

Higher dietary protein intake significantly improved physical endurance and marginally reduced intramuscular adiposity, but increased the inflammatory biomarker among middle-aged and older adults. Further study is needed to explore long-term effects of high-protein diet among middle-aged and older adults..

Proposed cut-off points for anthropometric and bioelectrical measures based on overweight and obesity criteria in Spanish institutionalised elderly people

The increasing prevalence of obesity among the institutionalised elderly population and its severe consequences on health requires an early and accurate diagnosis that can be easily achieved in any clinical setting. This study aimed to determine new cut-off values for anthropometric and bioelectrical impedance measures that are superior to body mass index criteria for overweight and obesity status in a sample of Spanish institutionalised elderly population. A total of 211 institutionalised older adults (132 women, aged 84.3±7.3 years; 79 men, aged 81.5±7.3 years) were enrolled in the current cross-sectional study. Anthropometric and bioelectrical impedance measures included the body mass index, waist circumference, gluteal circumference, waist-hip ratio, sagittal-abdominal diameter, trunk fat, and visceral-fat ratio. In women, the waist circumference, gluteal circumference, sagittal-abdominal diameter, trunk fat, and visceral-fat index presented strongly significant specificity and sensitivity (area under the curve [AUC], p<0.0001) and elevated discriminative values (receiver operating characteristic [ROC] curves: 0.827 to 0.867) for overweight and obesity status. In men, the waist-hip ratio, waist circumference, gluteal circumference, sagittal-abdominal diameter, trunk fat, and visceral-fat ratio were strongly significant AUC (p<0.0001), with moderate-to-high values (ROC curves: 0.757-0.871). In conclusion, our findings suggest that gluteal circumference, waist circumference, and sagittal-abdominal diameter in women and trunk fat, visceral-fat ratio, and waist circumference in men may represent more suitable cut-off values superior to body mass index criteria for overweight and obesity in the Spanish institutionalised elderly population.