Longitudinal association between visual disability and cognitive function among middle-aged and older adults in China.

Abstract

To determine the associations between visual disability and cognitive decline in Chinese middle-aged and older adults. A total of 6748 subjects were enrolled into this longitudinal, population-based, nationally representative study from two waves of the China Health and Retirement Longitudinal Study. Lagged dependent variable regression was used to model the independent associations between self-reported visual disability and cognitive function including memory and mental status. The mean age of the 6748 individuals was 56.33 years, and 3350 (49.6%) were women. The prevalence of visual disability was 3.8%, which increased with age (p<0.001). Both memory and mental status score worsened over time (all p<0.001). After controlling for covariates, lagged dependent variable regression models showed that visual disability at baseline was significantly associated with memory decline after 7 years (β=-0.252, p=0.046). After stratifying by age groups, this association was only significant in the 55-64 age group (β=-0.372, p=0.033). In addition, both memory and mental status in 2011 predicted memory decline over 7 years (p=0.024 and p=0.045, respectively). Our results suggest that visual disability may be a risk factor of memory decline, but not mental status among middle-aged and elderly adults in China. Future studies are needed to further corroborate the association between visual disability and cognitive decline and to determine whether interventions to preserve good visual function can prevent cognitive decline.