Physical Mobility, Social Isolation and Cognitive Function: Are There Really Gender Differences?

Objective This study aimed to examine the mediating role of social isolation between physical mobility and cognitive function, and whether there are gender differences in the above mediating effects among Chinese older adults. Methods This is a prospective and cohort study. We obtained data from the 2011 (Time 1, T1), 2015 (Time 2, T2) and 2018 (Time 3, T3) waves of China Health and Retirement Longitudinal Study, including 3,395 participants aged 60 years or above. Cognition was evaluated by Telephone Interview of Cognitive Status, words recall, and figure drawing, which was widely used in previous research. We used a cross-lagged model to test the hypothesis that social isolation mediated the association between physical mobility and cognitive function among Chinese older adults. Results The total effects of T1 physical mobility limitations on T3 cognitive function (β = -0.055, bootstrap p < 0.001) were significantly negative. Social isolation played a mediating role among both males and females (male: β = -0.008, bootstrap p = 0.012; female: β = -0.006, bootstrap p = 0.023), demonstrating that the mediating effect of social isolation between physical mobility and cognitive function was not gender specific. Conclusion This study confirmed that social isolation mediated the association between physical mobility and cognitive function among both Chinese male and female older adults. These findings indicate that reversing social isolation can be a priority intervention target for cognitive decline prevention and promote successful ageing, particularly among older adults with impaired physical mobility.