Previous researches have shown inconsistent findings on the relationship between sleep duration and cognitive disorders (including cognitive decline, dementia, Alzheimer's disease, and cognitive impairment). Furthermore, the possible dose-response association of sleep duration and cognitive disorders is still not clear.Two databases (PubMed and Embase) were searched for relevant studies from inception to May 4, 2016. We used the generic inverse-variance method to combine the outcomes with a random-effects model for the association between sleep duration (the shortest or longest vs. middle category) and cognitive disorders. Additionally, we used the generalized least-squares trend estimation model to estimate the potential dose-response association.Finally, nine eligible cohort studies involving 22,187 participants were included in the present systematic review and meta-analysis. Compared with the middle category, both short and long sleep duration were accompanied by a significantly higher incident risk of cognitive disorders, and the relative risks (RRs) and 95

作者：Lei, Wu；Dali, Sun；Yan, Tan

来源：Sleep & breathing = Schlaf & Atmung 2017 年