The Association between Sarcopenic Obesity and Impaired Activities of Daily Living among Middle-aged and Elderly Chinese: A Study Based on CHARLS

Objective This study aimed to investigate the association between sarcopenic obesity (SO) and impairments in basic activities of daily living (BADL) and instrumental activities of daily living (IADL) among middle-aged and elderly individuals. Methods Data were derived from the China Health and Retirement Longitudinal Study (CHARLS), with a final sample of 4,477 participants. Participants were categorized into four exposure groups: normal (no sarcopenia or obesity, n = 1,504), possible sarcopenia \(\:n=841\), obesity alone \(\:n=\text{1,870}\), and sarcopenic obesity \(\:SO,n=262\). Using BADL/IADL impairment as the outcome, multivariable logistic regression with stepwise adjustment across multiple models was employed to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results Baseline prevalence of BADL/IADL impairment showed a gradient increase across the four groups, with the highest rates observed in the SO group (18.32% for BADL, 45.80% for IADL). In the fully adjusted model, SO was significantly associated with both IADL impairment (OR = 1.90, 95% CI: 1.42–2.55) and BADL impairment (OR = 1.73, 95% CI: 1.15–2.58). No significant associations were found between obesity alone and IADL/BADL impairment. Possible sarcopenia was positively associated with IADL impairment (OR = 1.35, 95% CI: 1.10–1.66). Conclusion Sarcopenia-related exposures, particularly sarcopenic obesity, are significantly associated with ADL impairment. These findings suggest that both muscle mass/strength and body fat management should be prioritized in the prevention and control of functional decline among the elderly.