title: Sleep, Cognitive impairment, and Alzheimer's disease: A Systematic Review and Meta-Analysis.
abstract: Mounting evidence implicates disturbed sleep or lack of sleep as one of the risk factors for Alzheimer's disease (AD), but the extent of the risk is uncertain. We conducted a broad systematic review and meta-analysis to quantify the effect of sleep problems/disorders on cognitive impairment and AD.
  
  
  
  Original published literature assessing any association of sleep problems or disorders with cognitive impairment or AD was identified by searching PubMed, Embase, Web of Science, and the Cochrane library. Effect estimates of individual studies were pooled and relative risks (RR) and 95% confidence intervals (CI) were calculated using random effects models. We also estimated the population attributable risk.
  
  
  
  Twenty-seven observational studies (n = 69216 participants) that provided 52 RR estimates were included in the meta-analysis. Individuals with sleep problems had a 1.55 (95% CI: 1.25-1.93), 1.65 (95% CI: 1.45-1.86), and 3.78 (95% CI: 2.27-6.30) times higher risk of AD, cognitive impairment, and preclinical AD than individuals without sleep problems, respectively. The overall meta-analysis revealed that individuals with sleep problems had a 1.68 (95% CI: 1.51-1.87) times higher risk for the combined outcome of cognitive impairment and/or AD. Approximately 15% of AD in the population may be attributed to sleep problems.
  
  
  
  This meta-analysis confirmed the association between sleep and cognitive impairment or AD and, for the first time, consolidated the evidence to provide an "average" magnitude of effect. As sleep problems are of a growing concern in the population, these findings are of interest for potential prevention of AD.
authors.affiliation: Department of Epidemiology & Biostatistics, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: Omonigho M
authors.initials: OM
authors.lastname: Bubu
authors.affiliation: Psychology Department, College of Arts and Sciences, University of South Florida, Tampa, FL.
authors.forename: Michael
authors.initials: M
authors.lastname: Brannick
authors.affiliation: Department of Epidemiology & Biostatistics, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: James
authors.initials: J
authors.lastname: Mortimer
authors.affiliation: Department of Epidemiology & Biostatistics, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: Ogie
authors.initials: O
authors.lastname: Umasabor-Bubu
authors.affiliation: Department of Epidemiology & Biostatistics, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: Yuri V
authors.initials: YV
authors.lastname: Sebastião
authors.affiliation: Department of Chemical and Biomedical Engineering, College of Engineering, University of South Florida, Tampa, FL.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Department of Epidemiology & Biostatistics, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: Skai
authors.initials: S
authors.lastname: Schwartz
authors.affiliation: Department of Epidemiology & Biostatistics, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: Amy R
authors.initials: AR
authors.lastname: Borenstein
authors.affiliation: Department of Epidemiology & Biostatistics, College of Public Health, University of South Florida, Tampa, FL.
authors.forename: Yougui
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL.|Byrd Alzheimer Institute, Tampa, FL.
authors.forename: David
authors.initials: D
authors.lastname: Morgan
authors.affiliation: Sleep Medicine and Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL.
authors.forename: William M
authors.initials: WM
authors.lastname: Anderson
mesh_terms: D000544:Alzheimer Disease / Q000209:etiology*; D060825:Cognitive Dysfunction / Q000209:etiology*; D006801:Humans; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000150:complications*
keywords: Alzheimer’s disease; cognitive decline; dementia.; sleep disorders; sleep parameters; sleep problems