Night Sleep Duration and Risk of Cognitive Impairment in a Chinese Population： A Cross-sectional Study

• Published in: Biomedical and environmental sciences 2017-10, Vol.30 (10), p.749-757
• Main Authors: SONG, Qiao Feng, LIU, Xiao Xue, HU, Wan Ning, HAN, Xiao Chen, ZHOU, Wen Hua, LU, Ai Dong, WANG, Xi Zhu, WU, Shou Ling
• Format: Article
• Language: English
• Subjects: Cognitive; Cross-sectional; Impairment; Night sleep duration; 中国人群; 功能损害; 危险性; 多元回归分析; 横断面; 睡眠时间; 认知功能障碍; 认知障碍
• ISSN: 0895-3988; 2214-0190
• DOI: 10.3967/bes2017.100

Objective Although sleep is one of the most important health-related behavioral factors, the association between night sleep duration and cognitive impairment has not been fully understood. A cross-sectional study was conducted with a random sample of 2,514 participants （≥ 40 years of age; 46.6% women） in China to examine the association between night sleep duration and cognitive impairment. Methods Night sleep duration was categorized as ≤ 5, 6, 7, 8, or ≥ 9 h per night. Cognitive function was measured using the Mini-Mental State Examination. A multivariate regression analysis was used to analyze the association of night sleep duration with cognitive impairment. A total of 122 participants were diagnosed with cognitive impairment. Results A U-shaped association between night sleep duration and cognitive impairment was found. The odds ratios （95% confidence intervals） of cognitive impairment （with 7 h of daily sleep being considered as the reference） for individuals reporting ≤ 5, 6, 8, and ≥ 9 h were 2.14 （1.20-3.83）, 1.13 （0.67-1.89）, 1.51 （0.82-2.79）, and 5.37 （1.62-17.80）, respectively （P ≤ 0.01）. Conclusion Short or long night sleep duration was an important sleep-related factor independently associated with cognitive impairment and may be a useful marker for increased risk of cognitive impairment.