title: Physical activity and risk of cognitive impairment among oldest-old women.
abstract: OBJECTIVE
  Physical activity may reduce the risk of cognitive decline in the elderly, but its effects among the oldest-old (i.e., those aged 85 years and older) are not well known. Our study assessed the association between very late-life physical activity and 5-year risk of mild cognitive impairment (MCI) or dementia and neuropsychological test performance among oldest-old women.
  
  
  METHODS
  This prospective study was conducted at three sites. Participants included 1,249 women (mean [standard deviation] age: 83.3 [2.8] years). Baseline physical activity was measured by self-reported blocks walked per week and analyzed according to tertile. Five years later, surviving participants who were 85 years and older (oldest-old) completed neuropsychological testing and underwent adjudication of clinical cognitive status (normal, MCI, or dementia). All analyses were adjusted for baseline age, education, cognition, depression, body mass index, hypertension, smoking, and coronary artery disease.
  
  
  RESULTS
  Compared with women in the lowest tertile, women in the highest tertile were less likely to develop dementia (13.0% versus 23.2%; multivariate adjusted odds ratio: 0.54 [95% confidence interval: 0.36-0.82]). However, risk of MCI was not associated with physical activity. Physical activity was also associated with higher performance 5 years later on tests of global cognition, category fluency, and executive function but not phonemic fluency, memory, or attention.
  
  
  CONCLUSIONS
  Higher level of very late-life physical activity was associated with a lower risk of subsequent dementia in oldest-old women. These findings support future studies for late-life physical activity interventions for the prevention of dementia among oldest-old women.
authors.affiliation: Department of Psychiatry, University of California at San Francisco, San Francisco, CA; San Francisco VA Medical Center, San Francisco, CA. Electronic address: sophia.wang@ucsf.edu.
authors.forename: Sophia
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Psychiatry, Mount Sinai School of Medicine, New York, NY; Veterans Affairs Medical Center, Bronx, NY.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Luo
authors.affiliation: San Francisco VA Medical Center, San Francisco, CA; Departments of Psychiatry and Epidemiology and Biostatistics, University of California at San Francisco, San Francisco, CA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Barnes
authors.affiliation: Department of Psychiatry, Mount Sinai School of Medicine, New York, NY; Veterans Affairs Medical Center, Bronx, NY.
authors.forename: Mary
authors.initials: M
authors.lastname: Sano
authors.affiliation: San Francisco VA Medical Center, San Francisco, CA; Departments of Psychiatry, Neurology, and Epidemiology and Biostatistics, University of California at San Francisco, San Francisco, CA.
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
mesh_terms: D000369:Aged, 80 and over; D003071:Cognition; D060825:Cognitive Dysfunction / Q000209:etiology*; D003704:Dementia / Q000209:etiology*; D005260:Female; D006801:Humans; D009043:Motor Activity; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012307:Risk Factors
keywords: Cognitive aging; cohort studies; dementia; oldest-old; physical activity