A prospective study of age-related functional impairments, mortality, and life expectancy of Chinese adults aged 50

The population distribution of age-related functional impairments (ARFIs) and their associations with mortality and life expectancy (LE) among Chinese adults remain poorly understood.

We included 12,906 participants (mean age: 62.6 years) from the China Health and Retirement Longitudinal Study. Visual impairment, hearing impairment, cognitive impairment, sleep disorder, depressive symptoms, and disability in activities of daily living (ADL) were assessed. Cox proportional hazards models were used to estimate the associations of ARFIs with all-cause mortality. Life expectancy at age 50 was estimated by the presence and number of key ARFIs.

The six ARFIs exhibit distinct distributions by ages and provinces across China. During the 9-year follow-up, ADL disability, cognitive impairment, and depressive symptoms are independently associated with 64% (95% confidence interval [CI]: 48%-80%), 41% (21%-64%), and 20% (8%-33%) higher risks of mortality, corresponding to LE losses of 4.45, 3.08, and 1.59 years at the age of 50 years. A greater number of key ARFIs is associated with higher mortality risk in a dose-response manner (hazard ratios [95% CI] vs. none: 1.23 [1.11-1.36] for one, 1.42 [1.26-1.61] for two, and 1.86 [1.47-2.36] for three) and greater LE loss (1.63 [1.35-1.90] years for one, 3.37 [3.02-3.71] for two, and 4.96 [4.22-5.71] for three, with three ARFIs accounting for 17% of total LE).

The study highlights the important roles of co-existing ARFIs in mortality and LE loss. Integrated prevention strategies and management systems for multiple functional impairments are warranted in the context of rapid population aging.