Association between sleep duration and cognitive impairment in Chinese people aged 65 years and older

Abstract

Objective: To explore the association between sleep duration and cognitive impairment in older adults in China. Methods: The data was from 2018 Chinese Longitudinal Healthy Longevity Survey (CLHLS). According to the Chinese version of Mini-mental State Examination (CMMSE), 7 111 subjects aged 65 and above were divided into cognitive impaired group and cognitive intact group. Multiple logistic regression analysis was conducted to investigate the association between sleep duration and the risk of cognitive impairment after adjusting the potential confounding factors. Result: The score of cognitive function showed an inverted U-shape distribution with sleep duration. After adjusting for demographic, socioeconomic factors, lifestyle and health status, the OR were 1.21(95%CI: 0.90-1.64) and 1.41(95%CI: 1.06-1.86) in groups that sleep 8 h and ≥9 h per day respectively, compared with sleep 7 h group. Trend test showed that the risk of cognitive impairment in the elderly increased with the extension of sleep duration, and there was a dose-response relationship (trend P=0.017), while no association was observed between short sleep duration (<7 h) and cognitive function. Conclusion: Longer sleep duration was found to be associated with higher risk of cognitive impairment in the Chinese aged 65 years and older.