Declined intrinsic capacity predicts long-term mortality in Chinese older adults: Beijing Longitudinal Study of Aging

Background: Intrinsic capacity reflects an individual's functions and capacities across their lifetime. There are few studies on whether the level of intrinsic capacity can predict long-term mortality in Chinese populations. Objective: To explore the effects of intrinsic capacity on long-term outcomes in older Chinese adults. Methods: Data were obtained from the Beijing Longitudinal Study of Aging. Overall, 1699 community-dwelling adults aged >= 60 years were included and followed up for 8 years. Intrinsic capacity was determined according to the World Health Organization definition. The predictive ability for adverse outcomes was assessed using the age- and sex-adjusted Cox proportional hazards model. Results: A decline in intrinsic capacity domains was observed in 729 (42.9 %) participants. Declines in the mobility, cognition, vitality, sensory and psychology domains were observed in 21.8%, 15.1 %, 11.4%, 9.10%, and 14.2 % of the participants, respectively. Low intrinsic capacity was associated with worse physical performance, frailty, social frailty, chronic diseases, fracture, and falls. A greater decline in intrinsic capacity predicted an elevated 8-year mortality rate (decline in overall intrinsic capacity hazard ratio 2.91, 95% confidence interval 2.44-3.47, P < 0.001; decline in one domain hazard ratio 2.11, 95% confidence interval 1.71-2.61, P < 0.001; decline in two domains hazard ratio 3.54, 95 % confidence interval 2.81-4.45, P < 0.001; decline in three or more domains hazard ratio 5.30, 95 % confidence interval 4.09-6.87, P < 0.001); adjusted models did not affect prediction performance. Among the five domains of intrinsic capacity, cognition was the strongest predictor of mortality (hazard ratio 3.17, 95 % confidence interval 2.63-3.81, P < 0.001). Conclusions: Intrinsic capacity is useful in identifying older adults at higher risk of adverse outcomes, presenting significant implications for healthcare policies in China.