title: Impact of sleep on the risk of cognitive decline and dementia.
abstract: OBJECTIVE
  Trouble falling or staying asleep, poor sleep quality, and short or long sleep duration are gaining attention as potential risk factors for cognitive decline and dementia, including Alzheimer's disease. Sleep-disordered breathing has also been linked to these outcomes. Here, we review recent observational and experimental studies investigating the effect of poor sleep on cognitive outcomes and Alzheimer's disease, and discuss possible mechanisms.
  
  
  RESULTS
  Observational studies with self-report and objective sleep measures (e.g. wrist actigraphy, polysomnography) support links between disturbed sleep and cognitive decline. Several recently published studies demonstrate associations between sleep variables and measures of Alzheimer's disease pathology, including cerebrospinal fluid measures of Aβ and PET measures of Aβ deposition. In addition, experimental studies suggest that sleep loss alters cerebrospinal fluid Aβ dynamics, decrements in slow-wave sleep may decrease the clearance of Aβ from the brain, and hypoxemia characteristic of sleep-disordered breathing increases Aβ production.
  
  
  CONCLUSIONS
  Findings indicate that poor sleep is a risk factor for cognitive decline and Alzheimer's disease. Although mechanisms underlying these associations are not yet clear, healthy sleep appears to play an important role in maintaining brain health with age, and may play a key role in Alzheimer's disease prevention.
authors.affiliation: aDepartment of Mental Health, Johns Hopkins Bloomberg School of Public Health bDepartment of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine cDepartments of Neurology and Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland dDepartments of Psychiatry, Neurology, and Epidemiology and Biostatistics, University of California, San Francisco and San Francisco VA Medical Center, San Francisco, California, USA.
authors.forename: Adam P
authors.initials: AP
authors.lastname: Spira
authors.forename: Lenis P
authors.initials: LP
authors.lastname: Chen-Edinboro
authors.forename: Mark N
authors.initials: MN
authors.lastname: Wu
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
mesh_terms: D000544:Alzheimer Disease / Q000209:etiology* / Q000503:physiopathology; D003072:Cognition Disorders / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D064887:Observational Studies as Topic; D012307:Risk Factors; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000150:complications*