Can Changes in Social Isolation and Loneliness Affect Changes in Cognitive-Functional Impairment Among Chinese Older Adults? A 10-Year Longitudinal Study (2008-2018)

OBJECTIVE: This study examined how changes in social isolation and loneliness relate to transitions in cognitive-functional impairment (CFI) among Chinese older adults. METHODS: We used four waves (2008-2018) of CLHLS data and constructed an exploratory CFI indicator by combining MMSE and ADL measures. A two-state Cox regression model was applied to assess the effects of changes in social isolation and loneliness on CFI transitions. RESULTS: Among 11,704 observations aged 65 and above, 44.54% were aged 81-95 years and 51.14% were female. Overall, 18.24% of respondents became lonelier and 11.10% became socially isolated. In total, 13.91% showed cognitive impairment, 10.45% had functional limitations, and 4.87% had CFI. Changes in loneliness had a notably stronger effect on CFI transitions than changes in social isolation. Individuals who became lonely were more likely to develop new or persistent cognitive impairment, emerging functional limitations, and newly developed CFI (all adjusted hazard ratios (aHRs) > 1), whereas those who transitioned to a non-lonely state were less likely to remain cognitively-functionally impaired (aHR < 1). CONCLUSIONS: Rising loneliness may have a stronger impact on cognitive and functional decline than increasing social isolation. Early identification and intervention targeting loneliness could help support both cognitive and functional health among older adults.