Mediating Effect of Cognitive Reserve in the Relationship Between Physical Activity and Cognitive Function in Community-Dwelling Older Adults

The aim of this study was to investigate the mediating effect of cognitive reserve (CR) on the association between physical activity and cognitive function in community-dwelling older adults. A total of 495 community-dwelling older adults were included in this cross-sectional study. The CR, cognitive function, physical activity, and the potential confounders were assessed. Regression and bootstrap analyses were used to explore the mediating role of CR in physical activity and cognitive function. Compared to older adults with low to moderate physical activity, older adults with high physical activity had significantly better global cognitive function (βMoCA scores = 1.22, 95% CI 0.41 ~ 2.04) and visual spatial function (βCDT scores = 0.52, 95% CI 0.11 ~ 0.94) after adjustment for the confounders. CR mediated the association between physical activity and cognitive function with an indirect effect for global cognitive function (βMoCAscores = -0.29, 95% CI -0.56 ~ -0.09) and visual spatial function (βCDTscores = -0.14, 95% CI -0.28 ~ -0.05) after adjusting for the confounders, with 23.8% and 26.7% as percentage of mediation, respectively. These findings suggest that high physical activity could be effective in increasing cognitive reserve and preserving or improving cognitive function in community-dwelling older adults.