OBJECTIVE: To investigate the associations of body mass index (BMI), waist circumference (WC) and the weight-adjusted waist index (WWI) with the impairment of activities of daily living (ADL) in older Chinese people.
METHODS: A total of 13 260 participants aged 65 years and older from the 2018 Chinese Longitudinal Healthy Longevity Survey were included in this cross-sectional study. BMI, WC and the WWI were calculated from measurements of height, weight and WC. Binary logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). Non-linear correlations were investigated using restricted cubic spline curves.
RESULTS: In multivariate logistic regression fully adjusted for confounding variables, our analyses revealed significant associations between WC and WWI and ADL impairment, with adjusted ORs (95% CI) of 1.01 (1.00, 1.01) and 1.08 (1.03, 1.12), respectively. Meanwhile, participants with a high WWI had a higher risk of ADL impairment compared with those with a low WWI, with an adjusted OR (95% CI) of 1.12 (1.02, 1.23). Subgroup analyses showed that only the association between WWI and ADL impairment did not differ in any of the different populations. In addition, we found that BMI, WC and WWI were non-linearly associated with ADL impairment.
CONCLUSIONS: There are significant associations between WC and WWI and ADL impairment in older Chinese people. The findings show the ability of the WWI to serve as a comprehensive and effective indicator of obesity in older Chinese people and emphasize the importance of assessing WWI in screening and preventing ADL impairment in older people.

BACKGROUND: Studies examining the effects of social participation on activities of daily living (ADL) disability are still scarce.
OBJECTIVE: To assess the reciprocal relationship between ADL disability trajectories and social participation among older Chinese people aged ≥ 60 years.
METHODS: This study included 2976 participants aged ≥ 60 years in six waves of a community-based survey from 2015 to 2022. Basic activities of daily living (BADL) and instrumental activities of daily living (IADL) were used to assess the ADL disability in each survey. Social participation was assessed by involvement in four social activities and an extensive social participation score. Group-based trajectory modeling was used to identify potential heterogeneity in longitudinal changes over 7 years and explore associations between baseline predictors of group membership and these trajectories.
RESULTS: Two BADL disability trajectories were identified: stable (94.8%) and increase (5.2%). Additionally, three IADL disability trajectories were distinguished: stable (73.2%), moderate (20.2%), and increase (6.6%). After controlling for the potential covariates, each point increase in the extensive social participation score correlated with a 17% decrease in the odds of older individuals belonging to the increase BADL trajectory group (OR = 0.83, 95% CI = 0.68-1.00). For IADL, it decreased the odds of being assigned to the moderate trajectory group by 16% (OR = 0.84, 95% CI = 0.75-0.95) and to the increase trajectory group by 23% (OR = 0.77, 95% CI = 0.64-0.93).
CONCLUSIONS: Higher levels of social participation among older individuals were more likely to be classified as stable trajectories in both BADL and IADL. Increased participation in social activities by community-dwelling elderly adults may promote healthy aging.

The limitation of activities of daily living (ADL) affects the mental health of older adults. We distinguished activities of daily living into basic activities of daily living (BADL) and instrumental activities of daily living (IADL) and aimed to explore the relationship between the two limitations and depressive symptoms among Chinese older adults by using nationally representative cross-sectional data.
Data from the China Health and Retirement Longitudinal Study (CHARLS, wave 4) were used, and 9,789 older adults aged 60 years and above were screened. The 10-item Center for Epidemiologic Studies Depression (CES-D-10) scale was used to measure the depressive symptoms of older adults, and a 12-item scale for ADL was used to estimate functional limitations. Generalized linear mixed-effect models were employed to examine the relationship between BADL/IADL and depressive symptoms among older adults.
The prevalence of high-risk depression among older adults was 43.5%, and the rates of limitation in BADL and IADL were 19.02 and 25.29%, respectively. The prevalence of high-risk depression significantly differed among subgroups of smoking, drinking, chronic diseases, duration of sleep, having social activities or not, and the type of medical insurance. Older adults with limited BADL or IADL were at a higher risk of depression than those without limitations of BADL or IADL; BADL (OR-adjusted = 2.71; 95% CI: 2.40-3.06) and IADL (OR-adjusted = 2.68; 95% CI: 2.41-2.98) had various influences on the risk of depression in older adults.
ADL was a related factor in the risk of depression among older adults in China. BADL and IADL had different effects on the risk of depression, suggesting that older adults with physical function limitations might be more likely to suffer from depression.