Bidirectional Relationships and Mediating Effects Between Social Isolation, Loneliness, and Frailty in Chinese Older Adults.

Background and Objectives: Social isolation (SI) and loneliness are key factors that contribute to frailty among older adults. Current estimates regarding how frailty affects SI and loneliness and how SI and loneliness affect frailty may be flawed due to reverse causality. This study aimed to investigate the bidirectional relationships and mediating effects among SI, loneliness, and frailty among older adults in China. Research Design and Methods: The study analyzed data from 6 waves of the Chinese Longitudinal Healthy Longevity Survey conducted between 2002 and 2018. The sample included individuals aged 65 and older. The General Cross-Lagged Panel Model was used to account for confounding factors and reveal mediating effects. Results: Our findings specifically indicate a direct effect of SI on frailty, although suggesting that loneliness may indirectly affect frailty through its influence on SI. Additionally, frailty can lead to increased SI and loneliness. Discussion and Implications: SI and loneliness are strongly intertwined with frailty among older adults in China. To prevent the development of frailty, public health initiatives should prioritize reducing SI among older adults. Furthermore, efforts to decrease frailty levels can yield positive outcomes by mitigating both SI and loneliness among this population.