title: What sleep characteristics predict cognitive decline in the elderly?
abstract: BACKGROUND
  Sleep is critical for optimal cognitive function, but as we age both cognitive impairment and sleep problems increase. Longitudinal, population-based studies can be used to investigate temporal relationships between sleep and cognition.
  
  
  METHODS
  A total of 2012 cognitively unimpaired individuals 65 years and over were drawn from the MRC Cognitive Function and Ageing Study (CFAS). They answered self-reported measures including: insomnia symptoms and age of onset, night time wakings, snoring, sleep onset latency, napping, daytime sleepiness and duration of night time sleep. Cognition was measured via the Mini-Mental State Examination.
  
  
  RESULTS
  It was found that daytime napping at baseline was associated with a lower risk of cognitive decline at two and 10 years, and that obtaining ≤6.5h of night-time sleep and excessive daytime sleepiness at baseline were associated with an increased risk at 10 years.
  
  
  CONCLUSIONS
  Daytime napping, night-time sleep duration, and excessive daytime sleepiness may be modifiable behaviours open to intervention strategies, or, clinical indicators of future decline in older individuals.
authors.affiliation: Cognitive Neuroscience Laboratory, School of Psychology, Social Work and Social Policy, University of South Australia, Australia. hannah.keage@unisa.edu.au
authors.forename: Hannah Amy Dianne
authors.initials: HA
authors.lastname: Keage
authors.forename: Siobhan
authors.initials: S
authors.lastname: Banks
authors.forename: Kit Ling
authors.initials: KL
authors.lastname: Yang
authors.forename: Kevin
authors.initials: K
authors.lastname: Morgan
authors.forename: Carol
authors.initials: C
authors.lastname: Brayne
authors.forename: Fiona Elaine
authors.initials: FE
authors.lastname: Matthews
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003072:Cognition Disorders / Q000209:etiology*; D006970:Disorders of Excessive Somnolence / Q000150:complications; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000150:complications; D012893:Sleep Wake Disorders / Q000150:complications