A177: Association Between Physical Activity and the Risk of DepressionAmong Middle and Older Chinese People

<bold>Purpose:</bold> Relevant studies have shown that insufficient physical activity (PA) is associated with the risk of depression in middle-aged and elderly populations, but the relationship between different levels of PA and the risk of depression remains unexplored. Therefore, the objective of this study was to explore the relationship between different levels of PA and depression risk among middle-aged and older adults in China. <bold>Methods:</bold> The survey data of this study was based on the 2020 China Health and Retirement Longitudinal Study (CHARLS). A total of 13,316 middle-aged and elderly community residents aged 45 years or older with complete values of PA, depression assessment, and key variables were selected as the study subjects, and the PA levels and the prevalence of depression among middle-aged and elderly people were assessed based on the International Physical Activity Questionnaire (IPAQ) and the Center for Epidemiologic Studies Depression Scale (CESD), respectively. Multifactorial binary logistic regression models were developed to explore the effects of different levels of PA on the risk of depression in middle-aged and older adults, and sensitivity and stratification analyses were performed. Restricted cubic spline analysis was used to examine the possible non-linear relationship between physical activity and depression risk. <bold>Results:</bold> Multifactorial binary logistic regression analyses revealed that the odds of depression in middle-aged and older adults who participated in moderate and high levels of PA, using low levels of PA as a reference, was reduced by 15% [OR=0.85, 95% CI (0.73, 1), P=0.045] and 5% [OR=0.95, 95% CI (0.82, 1.11), P=0.541]. Sensitivity analyses showed that moderate levels of PA significantly reduced the risk of depression in middle-aged and older adults, indicating the robustness of the results. Stratified analyses showed that, compared with low levels of PA, moderate levels of PA significantly reduced the odds of depression in female middle-aged and older adults by 23% [OR=0.77, 95% CI (0.63, 0.95), P=0.013], and reduced the odds of depression by 30% in middle-aged and older adults living in inner-city areas [OR=0.7, 95% CI (0.54, 0.91), P=0.008], and reduced the odds of depression by 28% in 60- to 69-year-olds [OR=0.72, 95% CI (0.54, 0.94), P=0.017]. Restricted cubic spline plot results showed a non-linear dose relationship between PA levels and depression risk in middle-aged and older adults (P non-linearity=0.002). <bold>Conclusion:</bold> The study indicated that participation in moderate levels of PA associates with a reduction in the probability of depression in Chinese middle-aged and elderly people compared to low–high levels of PA.