The correlation of sleep with cognitive function in patients with Alzheimer's disease and mild cognitive impairment / 中华老年医学杂志

ABSTRACT

Objective:To explore whether sleep quality suffers in patients with mild Alzheimer's disease(AD)and mild cognitive impairment(MCI), and to further investigate the correlation between sleep disorders and cognitive function in these patients.Methods:In this study, 30 mild AD patients, 39 MCI patients and 43 demographically matched healthy controls were enrolled.Sleep quality was assessed by the Pittsburgh sleep quality index(PSQI), and cognitive function was assessed by the mini-mental state examination(MMSE), the Montreal cognitive assessment(MoCA)and a set of neuropsychological scales.The correlation of sleep quality with cognitive function was analyzed for the three groups.Results:Differences were significant in sleep time score[0.0(1.0), 1.0(2.0) vs.1.0(1.0), F=8.18, P=0.02]and daytime function score[1.0(1.0), 1.0(1.0) vs.0.0(1.0), F=8.73, P=0.01]between mild AD, MCI and health control groups.Spearman correlation analysis suggested that scores of sleep disorders were negatively correlated with DSB( r=-0.43, P=0.02)and scores of daytime function were positively correlated with ADL( r=0.39, P=0.03)in patients with mild AD.In addition, scores of sleep quality were negatively correlated with the DSB score( r=-0.40, P=0.01), scores of sleep disorders were positively correlated with ADL( r=0.45, P<0.01), scores of daytime function were negatively correlated with DSF( r=-0.42, P=0.01), DSB( r=-0.62, P<0.01)and VFT-S( r=-0.33, P=0.04), and the total PSQI score was negatively correlated with DSF( r=-0.45, P=0.01)and DSB( r=-0.44, P=0.01)in the MCI group. Conclusions:Patients with mild AD and MCI have longer sleep time and impaired daytime function than healthy people, and sleep quality is correlated with memory, attention and daily living ability in patients with mild AD and MCI.