Sleep Disturbance is Associated With Cognitive Impairment: a Community Population-based Cross-sectional Study

Abstract Background: Sleep is an important physiological process and conducive to the elimination of brain metabolites and the recovery of brain function. However, the relationship between sleep disturbance and cognitive impairment is not fully been determined.Methods: This was a community population-based cross-sectional study. A total of 1,461 participants from a village in the suburbs of Xi’an, China were enrolled from January 3 to March 26, 2017. Sleep quality was evaluated using the Pittsburgh sleep quality index (PSQI), and sleep disturbance was defined as a PSQI score >5. Mini-mental state examination (MMSE) was used to assess cognitive function and cognitive impairment was defined as the MMSE score less than cutoff values and meets the diagnostic criteria. Univariate and multivariate analyses were used to analyze the relationships between sleep disturbance and cognitive impairment.Results: Among 1,461 subjects, 87(5.95%) had cognitive impairment, and 842 (57.63%) had sleep disturbance. In bivariate analysis, cognitive impairment was associated with insomnia (ρ=1.000, P＜0.001), age (ρ=0.172, P＜0.001) and educational level (ρ=-0.160, P＜0.001). In the binary logistic regression, cognitive impairment was positively associated with the sleep disturbance (OR=1.779, 95%CI=1.055-3.001, P=0.031). In the internal constitution of PSQI, cognitive impairment was positively associated with the sleep interference (OR=1.678; 95%CI=1.029-2.736, P=0.038), and negatively associated with the habitual sleep efficiency (OR=0.115, 95%CI=0.043-0.306, P<0.001). However, people sleep more than 8 hours a day are more likely to suffer from cognitive impairment (OR=3.174, 95%CI=1.570-6.417, P=0.001). Conclusions: Sleep disturbance is associated with cognitive impairment. However, the causal relationships between sleep disturbances and cognitive impairment are not clear. It needs to be further studied.