Physical Activity and Health-Related Quality of Life in Older Adults: Depression as a Mediator

Background: Physical activity is associated with health-related quality of life (HRQoL) among older adults, and both are associated with mood, such as depression. However, the indirect effects of physical activity on HRQoL in older adults have not been clearly established. This study explains how physical activity is associated with HRQoL while considering the effects of depression in older adults. Methods A cross-sectional study was conducted with 7,518 community-dwelling older adults aged 60 years and older. Physical activity, depression, and HRQOL were measured using the Physical Activity Scale for the Elderly, the 30-item Geriatric Depression Scale, and the 36-Item Short-Form Health Survey (SF-36), respectively. Physical activity included three types of activities: leisure, household, and work. Information on age, gender, education, monthly income, physical functioning, smoking, and alcohol use were also collected. Results The multivariate analyses showed that after adjusting for sociodemographic variables, SF-36 Physical Component Summary scores were negatively associated with depression (B = -2.046, 95% CI [2.584, -1.509]) and positively with physical activity (p < 0.001). Similarly, SF-36 Mental Component Summary scores were negatively associated with depression (B = -11.657, 95% CI [-12.190, -11.124]). In the mediation analysis, different types and levels of physical activity positively correlated with HRQoL (p < 0.001), and depression negatively correlated with physical activity and HRQoL (p < 0.001). Conclusions The findings showed that lighter amounts of physical activity and worsening HRQoL in Chinese older adults were independently associated. In addition, the relationship between physical activity and HRQoL was partially mediated by depression. It is recommended that geriatric health care administrators and health care planners prioritize improving physical activity levels in older adults to promote the reduction of depressive symptoms in older adults to improve the beneficial effects on HRQoL.