title: Physical activity and the risk of dementia in oldest old.
abstract: OBJECTIVE
  This study evaluated the protective role of physical activity (PA) against cognitive impairment (CI) in the oldest old (age >/= 85).
  
  
  METHODS
  Prospective data on 66 optimally healthy, oldest old adults (mean age 88.5) were analyzed using survival analysis.
  
  
  RESULTS
  In all, 12 men and 11 women reported exercising > 4 hours per week, and 38 participants developed CI (mean onset age 93; mean follow-up 4.7 years). The effect of exercise was modified by gender. In more active women (> 4 hours/week), the risk of CI was reduced by 88% (95% confidence interval 0.03, 0.41) compared to those less active. Less active women had 2 times the incidence rate of CI compared to less active men and almost 5 times the rate compared to active women.
  
  
  CONCLUSIONS
  This study demonstrates the beneficial effects of exercise on healthy brain aging even in the oldest old and emphasizes the importance of increasing PA in older women.
authors.affiliation: Department of Public Health and Preventive Medicine, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Rd. Campus Services Building 669, Mail Code CB-669, Portland, Oregon 97201-3098, USA. sumica@ohsu.edu.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Sumic
authors.forename: Yvonne L
authors.initials: YL
authors.lastname: Michael
authors.forename: Nichole E
authors.initials: NE
authors.lastname: Carlson
authors.forename: Diane B
authors.initials: DB
authors.lastname: Howieson
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kaye
mesh_terms: D000369:Aged, 80 and over; D003072:Cognition Disorders; D003704:Dementia; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D009922:Oregon; D011446:Prospective Studies; D012307:Risk Factors