Association of Sensory Impairments with Cognitive Decline and Depression among Older Adults in China

Abstract

Importance: Sensory impairments may heighten the risk of premature brain aging. Little is known regarding the association of sensory impairments with cognitive function and depression in China. Objective: To examine the association of visual and/or hearing impairments with cognitive decline and depression. Design, Setting, and Participants: This cross-sectional study used the data from 18038 respondents to the 2015 survey of the China Health and Retirement Longitudinal Study, a nationally representative survey of adults aged 45 years or older and their spouses. Exposures: The presence of sensory impairments was identified by self-reported assessment of visual and/or hearing functions. Main Outcomes and Measures: Overall, 3 composite measures were used to assess the respondents' cognitive performance, including episodic memory, mental intactness, and global cognitive function. Depression was examined using the 10-item Center for Epidemiological Studies-Depression scale score. Multiple generalized linear regression models, adjusting for self-reported sociodemographic characteristics, health behaviors, chronic conditions, and participants' overall health, were used. Results: Of 18038 respondents, 9244 (51.2%) were women. The mean (SD) age was 59.9 (9.7) years. Respondents with visual impairment had poorer episodic memory (β = -0.12; 95% CI, -0.19 to -0.05) and global cognition (β = -0.16; 95% CI, -0.31 to -0.02) and a greater risk of depression (odds ratio, 1.78; 95% CI, 1.59 to 1.99) than those without visual impairment. Respondents with hearing impairment had poorer episodic memory (β = -0.24; 95% CI, -0.30 to -0.18), mental intactness (β = -0.19; 95% CI, -0.28 to -0.10), and global cognition (β = -0.43; 95% CI, -0.55 to -0.31) as well as a greater risk of depression (odds ratio, 1.57; 95% CI, 1.44 to 1.70) than those without hearing impairment. People who reported dual sensory impairment performed worse on all of the aforementioned outcome measures (episodic memory: β = -0.23; 95% CI, -0.31 to -0.14; mental intactness: β = -0.13; 95% CI, -0.27 to -0.0003; global cognition: β = -0.37; 95% CI, -0.55 to -0.19; depression: odds ratio, 2.19; 95% CI, 1.90 to 2.52). Conclusions and Relevance: In this study, visual and hearing impairments were independently and together associated with poorer cognitive and depression outcomes. A more comprehensive and integrated system of care, covering vision, hearing, and cognition, is needed in China's health care system to address age-related sensory impairments..