Abstract: Objective To explore the effects of sleep duration and sleep efficiency on cognitive function of the elderly with mild cognitive impairment in rural areas. Methods A total of 114 elderly with mild cognitive impairment in rural areas were enrolled in this study. Pittsburgh Sleep Quality Index (PSQI) and Montreal Cognitive Assessment (MoCA) were used to investigate the sleep quality and cognitive function. According to sleep efficiency, the elderly were divided into 3 groups: > 85% group, 75%-85% group and <75% group. According to the sleep duration, they were divided into 3 groups: ≤6 h group, (6,8) h group and ≥8 h group. Results Except for the abstract dimension, the scores of MoCA showed significant correlation with the scores of PSQI in the elderly people with mild cognitive impairment in rural areas (P＜0.05). Compared with ≥8 h group, the scores of MoCA including the dimensions as visual space and executive function, naming, delayed recall were significantly lower, and the scores of PSQI, including the dimensions as subjective sleep quality, sleep time, sleep efficiency were significantly higher in ≤6 h group (P<0.05). Compared with ＜75% group, the scored of MoCA including the dimensions as naming and orientation were significantly higher, and the scores of PSQI, including the dimensions as subject sleep quality, sleep latancy, sleep time and sleep effitiency were significantly lower in ＞85% group. Conclusions Sleep duration and sleep efficiency have significant effects on the cognitive function in the elderly in rural areas. Therefore, improving the sleep quality of the elderly with mild cognitive impairment in rural areas will contribute to the improvement of the cognitive function.

Key words: sleep duration, sleep efficiency, cognitive function, mild cognitive impairment, aged