睡眠与认知减退的关系：西安农村人群4年前瞻性队列研究

Objective To investigate sleep's impact on 4-year cognitive decline in rural middle-aged and elderly populations in Xi'an. Methods Using the “cognitive impairment cohort of middle-aged and elderly people in rural areas of Xi'an”, we analyzed cognitively normal participants from 2016 with a 4-year follow-up completed in 2020. Sleep was assessed via Pittsburgh Sleep Quality Index (PSQI: 7 domains including sleep efficiency). Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Cognitive decline was defined as a drop of ≥2 points on the MMSE. Relationships between sleep and cognitive decline were examined using univariate analysis and multivariate Logistic regression. Results A total of 1660 participants (mean age 57.40± 9.71 years; 40.9% men; 57.47% PSQI＞5). In the analysis of the 4-year follow-up cohort, univariate analysis showed that the PSQI sleep efficiency subscore was significantly higher in the cognitive decline group than in the cognitively stable group (1.41±1.22 vs. 1.26±1.22,P=0.036). No significant association was found in the other PSQI domains. Multivariate analysis demonstrated increased cognitive decline risk with low sleep efficiency (OR=3.039,95% CI:1.240-7.448,P=0.015) and significant sleep efficiency × education interaction (OR=0.836, 95% CI:0.701-0.996,P=0.045). indicating that higher education attenuated the effect of sleep efficiency on cognitive decline. Stratified analysis revealed a higher cognitive decline incidence with low sleep efficiency in the females (33.4% vs. 25.6%,P=0.017) and the illiterates (48.1% vs. 25.0%,P=0.014), with elevated adjusted risk in the former (OR=1.152,95% CI:1.011-1.313,P=0.034) and in the latter (OR=1.564,95% CI:1.113-2.200,P=0.010). Conclusion Sleep efficiency exhibits gender- and education-dependent associations with cognitive decline, showing significantly higher 4-year risk in women and illiterates with low sleep efficiency.