title: Midlife Physical Activity and Cognition Later in Life: A Prospective Twin Study.
abstract: Physical activity has been associated with a reduced risk of cognitive decline but the nature of this association remains obscure.
  
  
  
  To study associations between midlife physical activity and cognition in old age for a prospective cohort of Finnish twins.
  
  
  
  Physical activity in the Finnish Twin Cohort was assessed using questionnaire responses collected in 1975 and 1981. After a mean follow-up of 25.1 years, the subjects' (n = 3050; mean age 74.2; range 66-97) cognition was evaluated with a validated telephone interview. Both participation in vigorous physical activity, and the volume of physical activity, divided into quintiles, were used as predictors of cognitive impairment. Metrics collected by TELE were used to categorize participants as: cognitively impaired, suffering mild cognitive impairment, or cognitively healthy.
  
  
  
  Participation in vigorous physical activity compared to non-participation for both 1975 and 1981 was associated with a lower risk of cognitive impairment in individual-based analyses (fully adjusted OR 0.50, 95% CI 0.35-0.73). Pairwise analyses yielded similar but statistically non-significant associations. In terms of the volume of physical activity, the most active quintile of individuals (OR 0.69, 95% CI 0.46-1.04) had a reduced risk of cognitive decline compared with the most sedentary quintile in the fully adjusted model although no clear dose-response was found.
  
  
  
  Vigorous midlife physical activity was associated with less cognitive impairment but without a clear dose-response association between the volume of physical activity and cognition.
authors: Department of Clinical Physiology and Nuclear Medicine, HUS Medical Imaging Center, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.
authors: Paula
authors: P
authors: Iso-Markku
authors: Department of Health Sciences, University of Jyväskylä, Finland.
authors: Katja
authors: K
authors: Waller
authors: Department of Public Health, University of Helsinki, Finland.|Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland.
authors: Eero
authors: E
authors: Vuoksimaa
authors: Department of Public Health, University of Helsinki, Finland.
authors: Kauko
authors: K
authors: Heikkilä
authors: Clinical Neurology, Turku PET Centre, University of Turku, Turku, Finland.
authors: Juha
authors: J
authors: Rinne
authors: Department of Public Health, University of Helsinki, Finland.|Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland.|Department of Health, National Institute for Health and Welfare, Helsinki, Finland.
authors: Jaakko
authors: J
authors: Kaprio
authors: Department of Health Sciences, University of Jyväskylä, Finland.
authors: Urho M
authors: UM
authors: Kujala
mesh_terms: D000328:Adult; D000368:Aged; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000453:epidemiology / Q000235:genetics* / Q000517:prevention & control*; D060825:Cognitive Dysfunction / Q000453:epidemiology / Q000235:genetics / Q000517:prevention & control; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
keywords: Cohort studies; cognition; dementia; exercise; genetics