Sedentary Behavior and Physical Frailty Among Rural Older Adults in China: The Moderating Effect of Social Isolation

Few studies have explored the mechanisms underlying the relationship between sedentary behavior and physical frailty. The aim of this study was to investigate the moderating effect of social isolation on the association between sedentary behavior and physical frailty among older adults in rural China.Cross-sectional study.Data were from 3238 individuals aged ≥60 years from rural areas in China.Binary logistic regression was used to explore the association between sedentary behavior and physical frailty and the moderating effect of social isolation.The prevalence of physical frailty was 18.7% among the older adults, and 17.0% of them were sedentary for ≥8 h/d. Compared with older adults with sedentary behavior for <4 h/d, participants with sedentary behavior for ≥8 h/d were more likely to suffer from physical frailty [odds ratio (OR), 2.26; 95% CI, 1.57-3.27]. We found that social isolation may aggravate this relationship (OR, 3.31; 95% CI, 2.06-5.32), especially for rural older adults who were sedentary for ≥8 h/day.More sedentary behavior was associated with higher risk of physical frailty, which was especially apparent among older adults with social isolation, suggesting that sedentary older people who experienced social isolation were more vulnerable to physical frailty. Decreasing sedentary behavior in older adults and encouraging them to participate in interactive social activities could help prevent physical frailty.