[Association between physical activity and sarcopenia among older adults aged 65 and above in longevity areas of...

Objective: To explore the association between total physical activity, different types of activities, and sarcopenia among older adults aged 65 years and above in 18 longevity areas of China. Methods: The study participants were from the Healthy Ageing and Biomarkers Cohort Study (HABCS) conducted in 2021 across 18 longevity areas in China, with a total of 5 224 adults aged 65 years and above included. Information of sociodemographic characteristics, lifestyle, and physical measurements was collected through questionnaires and physical examinations. Total physical activity was assessed by the Physical Activity Scale for the Elderly (PASE), and the prevalence of sarcopenia was evaluated by the SARC-CalF scale. Participants were categorized into four groups based on their total score of physical activity: no physical activity and, among those with activity, low, moderate, and high levels defined by the tertiles of the activity score. Multivariate logistic regression was employed to analyze the association between physical activity score and sarcopenia. Restricted cubic splines (RCS) were used to examine the exposure-response relationships between physical activity score and sarcopenia. Results: The mean age of the 5 224 participants was (85.42±11.56) years. The total physical activity, leisure-time activity, and household activity score [M (Q₁, Q₃)] were: 52.20 (8.60, 106.00), 8.60 (0.00, 21.40), and 35.00 (0.00, 81.00), respectively. The prevalence of sarcopenia was 50.36%. Multivariate logistic regression analysis showed that after adjusting for confounders, for every increase of one interquartile range (IQR) in total physical activity score, the risk of sarcopenia decreases by 58% (OR=0.42, 95%CI: 0.37-0.49). Compared with inactive individuals, the risks of sarcopenia were reduced by 40% (OR=0.60, 95%CI: 0.48-0.75), 59% (OR=0.41, 95%CI: 0.33-0.52) and 73% (OR=0.27, 95%CI: 0.21-0.34) in the low, moderate, and high physical activity groups, respectively, with a significant exposure-response relationship (P_{for trend}<0.001). RCS analysis showed a linear negative relationship between total physical activity score and sarcopenia risk (P_overall<0.001, P_nonlinear=0.290). Among individuals who engaged only in leisure physical activity (n=1 733), multivariate logistic regression analysis showed that for every increase of one IQR in leisure activity score, the risk of sarcopenia decreased by 15% (OR=0.85, 95%CI: 0.79-0.92). Compared with the inactive group, the low, moderate, and high leisure activity groups exhibited 41%, 62%, and 61% reductions in sarcopenia risk, respectively, with a significant exposure-response trend (P_{for trend}<0.001). RCS analysis revealed a non-linear negative association between the leisure activity score and sarcopenia risk (P_overall<0.001, P_non-linear=0.001). Among individuals who engaged only in household physical activity (n=2 093), multivariate logistic regression analysis indicated that for every increase of one IQR in household activity score, the risk of sarcopenia decreased by 31% (OR=0.69, 95%CI: 0.60-0.80). Compared with the inactive group, the low, moderate, and high household activity groups showed 26%, 42%, and 58% reductions in sarcopenia risk, respectively (P_{for trend}<0.001). RCS analysis demonstrated a linear negative association between the household activity score and sarcopenia risk (P_overall<0.001, P_non-linear=0.579). Conclusion: Increased total physical activity and active engagement in household or leisure activities are associated with a reduced risk of sarcopenia among older adults in longevity areas of China.