The effect of social isolation on sarcopenia: a longitudinal study among the middle-aged and older population in China

Introduction: Although social isolation is associated with premature death and somatic and mental diseases, evidence of its long-term effect on sarcopenia is scarce. This study aimed to examine the longitudinal association between social isolation and possible sarcopenia. Methods: We extracted baseline and four-year follow-up data from the China Health and Retirement Longitudinal Study and included participants aged 45 years or above. Social isolation was measured by factors including living alone, marital status, frequency of contact with adult children and friends, and participation in social activity. The change in social isolation from baseline to follow-up was classified into stable, progressive, and regressive groups. Possible sarcopenia was detected using the handgrip strength and five-time chair stand test. Using mixed effects logistic regression, we studied the effect of baseline isolation and the change in isolation status on possible sarcopenia at a four-year follow-up. Results: A total of 5289 participants aged 45 to 90 years and without possible sarcopenia at baseline were included. After four years, possible sarcopenia was detected in 21.7% (1146/5289) of the participants. Compared with the low social isolation group, the middle (OR=1.53, 95% confidence interval [CI]=1.16 similar to 2.04, p=0.003) and high social isolation groups (OR=1.65, 95% CI=1.26 similar to 2.18, p<0.001) were associated with a higher risk of possible sarcopenia. Being not married/cohabiting (OR=1.58, 95% CI=1.19 similar to 2.10, p=0.002), lack of contact with children (OR=1.86, 95% CI=1.21 similar to 2.85, p=0.004), and lack of social activities (OR=1.26, 95% CI=1.04 similar to 1.53, p=0.019) were associated with an increased risk of possible sarcopenia. Compared with the stable social isolation group, the progressive group was associated with a greater risk of possible sarcopenia (OR=1.51, 95% CI=1.17 similar to 1.95, p=0.001). Conclusions: Social isolation is associated with an increased risk of possible sarcopenia. Progressive social isolation further elevates the risk. The most vulnerable groups are middle-aged and older people who live alone, are not socially active, and lack contact with their children.

Automated summary

This study aimed to examine the long-term association between social isolation and possible sarcopenia. The research found that social isolation was closely associated with an increased risk of possible sarcopenia, and progressive social isolation further elevated the risk. The most vulnerable groups were middle-aged and older individuals who lived alone, were not socially active, and lacked contact with their children.