Objective The purpose of this study was to examine the relationships of social isolation and loneliness, both individually and simultaneously, on changes in grip strength among Chinese older adults and whether these relations vary by gender.
Design A 4-year prospective observational study.
Setting and Participants This study used data from the China Health and Retirement Longitudinal Study (CHARLS). Analyses were conducted with data from 2 waves (2011 and 2015) and were restricted to those respondents aged 50 and older [n =7025, mean age (SD) = 61.46 (7.59); male, 48.4%].
Methods Social isolation, loneliness, and grip strength were measured at baseline. Follow-up measures of grip strength were obtained 4 years later. Multiple linear regression was used to evaluate the associations among baseline isolation, loneliness, and decline of grip strength between 2 waves after adjustment for age, gender, education, body mass index, chronic diseases, smoking and drinking status, activities of daily living (ADL) and instrumental ADL disabilities, and depressive symptoms.
Results For women, baseline loneliness (b = 0.04, P = .035) rather than isolation (b = 0.03, P = .110) significantly predicted grip strength decline after 4 years when other confounding variables were taken into account. For men, baseline isolation (b = 0.05, P = .005) rather than loneliness (b = 0.01, P = .570) significantly predicted grip strength decline. No synergistic effect of isolation and loneliness on grip strength was found for either women or men.
Conclusions and Implications In this prospective study, gender differences were found for the associations of social isolation and loneliness with grip strength decline. Our results suggest that older women and men may benefit from different social enhancement strategies for prevention of physical function decline.