title: Sleep duration during the 24-hour day is associated with the severity of dementia in nursing home patients.
abstract: OBJECTIVE
  To describe the characteristics of 24-h sleep patterns in nursing home patients with dementia, and to determine whether various degrees of dementia have any influence on total sleep duration.
  
  
  METHODS
  Cross-sectional study in a nursing home population (n = 23) consisting of patients with varying degree of dementia. Sleep was measured with actigraphy for a consecutive period of 14 days, based on individual bed and rising time, which was registered by nursing home staff.
  
  
  RESULTS
  Mean age +/- standard deviation was 86.1 +/- 7.0 (range 72-96) and mean Mini-Mental Status Examination Score (MMSE) was 13.4 +/- 5.3 (range 1-21). Ten patients had MMSE < or = 12. Sleep was extremely fragmented, with frequent wake bouts during nighttime and frequent naps during daytime. During the 24-h period, patients spent nearly 13 h asleep, distributed as more than 9 h of nighttime sleep and more than 3 h of daytime sleep. Patients with severe degree of dementia (MMSE < or = 12) slept significantly longer during the 24-h day than patients with lesser degree of dementia (MMSE > 12). There was no significant difference in age between the dementia sub-groups.
  
  
  CONCLUSIONS
  Sleep duration during the 24-h day was positively correlated with the severity of dementia in nursing home patients. This is in contrast with total sleep time seen in healthy elderly, which shows a gradually decline with age. Changes in sleep patterns in dementia could be explained by co-morbid and environmental factors, as well as unknown pathological changes related to dementing illnesses.
authors.affiliation: Department of General Practice and Community Medicine, University of Oslo, Norway. arne.fetveit@medisin.uio.no
authors.forename: Arne
authors.initials: A
authors.lastname: Fetveit
authors.forename: Bjørn
authors.initials: B
authors.lastname: Bjorvatn
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000503:physiopathology; D002940:Circadian Rhythm; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D009735:Nursing Homes; D012720:Severity of Illness Index; D012890:Sleep; D020178:Sleep Disorders, Circadian Rhythm / Q000209:etiology*