Do Sensory Impairments Portend Cognitive Decline in Older Chinese Adults? Longitudinal Evidence from a Nationally Representative Survey, 2011–2018

Abstract

Previous studies on longitudinal sensory-cognition association are limited and have yielded inconsistent conclusions in western and developed countries. The present study obtained data from the China Health and Retirement Longitudinal Survey (CHARLS, 2011–2018) and aimed to investigate the longitudinal effects of sensory impairments including single vision impairment (SVI), single hearing impairment (SHI), and dual sensory impairment (DSI) on cognitive decline in middle-aged and older Chinese population. In total, 11,122 participants accomplished all 4 interviews over 8 years and were included. Cognitive performances were assessed using Mini-Mental Status Examination (MMSE) and self-reported sensory status were accepted as well. Confounding variables included age, sex, educational level, marital status, medical, and lifestyle related information. The impact of sensory impairment on cognitive decline over time was assessed using linear mixed-effects models (LMM). After being adjusted for multiple confounders, SVI/SHI/DSI were all shown to be significantly associated with executive functions, episodic memory impairment, and global cognitive decline over 8 years (all p < 0.05). Such associations become less significant among female and relatively younger populations (45–59 years old). Single vision and hearing impairments, along with dual sensory impairment, are all independently associated with subsequent cognitive decline among middle-aged and older Chinese populations over 8 years of longitudinal observation.

Associations of visual, hearing, and dual sensory impairment with motoric cognitive risk syndrome: Observational and Mendelian randomization analyses

“…Participants were considered to have DSI when both VI and HI were present. The evaluation and classification of sensory impairments were consistent with previous studies in CHARLS 24–26 …”

“…Firstly, sensory impairments were selfreported by participants, and there may be selection bias. Although this method has been extensively used in similar studies [24][25][26] and there is evidence to suggest that self-evaluation of vision and hearing status may be more intuitive than clinical measurements. 50 Secondly, some unmeasured potential confounding factors were not included…”

“…The evaluation and classification of sensory impairments were consistent with previous studies in CHARLS. [24][25][26]…”

Is there a correlation between sensory impairments and social isolation in middle-aged and older Chinese population? Cross-sectional and longitudinal evidence from a nationally representative survey

“…Similarly, for the HI assessment, the question was: “Is your hearing excellent, very good, good, fair or poor.” A response of fair or poor hearing was identified as HI. Such assessment of SI has been widely used in previous CHARLS-related studies ( 29 – 31 ). DSI refers to the condition in which participants reported both VI and HI, and single SI refers to sole VI or HI without the other one.…”

“…Older Chinese are likely to neglect SI and related problems owing to their traditional attitudes regarding SI as a normal part of aging life, which might further contribute to the higher prevalence of SI and SI-related problems in China than that in some western countries ( 28 ). Several studies have indicated the associations between SI and adverse health consequences in the older Chinese population ( 29 – 31 ). However, to the best of our knowledge, there is a paucity of literature on SIs and social isolation in our aging population.…”