title: Self-reported sleep disturbance and incidence of dementia in ageing men.
abstract: Sleep disturbance is suggested to contribute to the development of dementia. However, prospective longitudinal data from middle-aged populations are scarce.
  
  
  
  We investigated a population-based sample of 2386 men aged 42-62 years at baseline during 1984-1989. Participants having a history of mental illnesses, psychiatric medication, Parkinson's disease or dementia within 2 years after baseline (n=296) were excluded. Difficulty falling asleep or maintaining sleep, sleep duration and daytime tiredness were enquired. Dementia diagnoses (n=287) between 1984 and 2014 were obtained through linkage with hospital discharge, national death and special reimbursement registers. Cox proportional hazards analyses were performed for all dementias, and separately for Alzheimer's disease (n=234) and other phenotypes (n=53). Additional analyses were performed on a subsample of an apolipoprotein E (APOE) genotype-tested population (n=1199).
  
  
  
  The risk ratio for dementia was 1.58 (95% CI 1.10 to 2.27) in men with frequent sleep disturbance after adjustments for age, examination year, elevated depressive symptoms, physical activity, alcohol consumption, cumulative smoking history, systolic blood pressure, body mass index, low-density lipoprotein and high-density lipoprotein cholesterol, high-sensitivity C reactive protein, cardiovascular disease history, education years and living alone. Daytime tiredness and sleep duration were not associated with dementia in adjusted analysis. In theAPOEsubsample, bothAPOEε4 genotype and frequent sleep disturbance were associated with increased dementia risk, but in the interaction analysis they had no joint effect.
  
  
  
  Self-reported frequent sleep disturbance in middle-aged men may relate to the development of dementia in later life. Having anAPOEε4 genotype did not affect the relationship.
authors.affiliation: Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland.
authors.forename: Maria K
authors.initials: MK
authors.lastname: Luojus
authors.affiliation: Institute of Clinical Medicine/Psychiatry, University of Eastern Finland, Kuopio, Finland.|Department of Psychiatry, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Soili M
authors.initials: SM
authors.lastname: Lehto
authors.affiliation: Institute of Clinical Medicine/Psychiatry, University of Eastern Finland, Kuopio, Finland.|Department of Psychiatry, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Tommi
authors.initials: T
authors.lastname: Tolmunen
authors.affiliation: Max Planck Institute of Psychiatry, Munich, Germany.|Department of Experimental Psychology, University of Oxford, Oxford, UK.|Department of Neurology, Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Anna-Katharine
authors.initials: AK
authors.lastname: Brem
authors.affiliation: Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland.
authors.forename: Eija
authors.initials: E
authors.lastname: Lönnroos
authors.affiliation: Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Kauhanen
mesh_terms: D000328:Adult; D000375:Aging; D003704:Dementia / Q000453:epidemiology*; D003863:Depression / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D057566:Self Report; D012890:Sleep; D020178:Sleep Disorders, Circadian Rhythm / Q000453:epidemiology*
keywords: AGEING; DEMENTIA; Epidemiology of chronic diseases; SLEEP