title: Effects of cardiorespiratory fitness and cerebral blood flow on cognitive outcomes in older women.
abstract: The mechanisms by which aerobic fitness confers beneficial effects on cognition with aging are unclear but may involve cerebrovascular adaptations. In a cross-sectional study of women from the community (n=42; age range=50-90 years), we sought to determine whether physical fitness is associated with higher cerebrovascular function, and its relationship to cognition. Main outcome measures included resting cerebral blood flow, cerebrovascular reserve, physical fitness (i.e., VO₂max) and cognition. Physically fit women had lower resting mean arterial pressure (MAP) and higher cerebrovascular conductance (CVC) than sedentary women. Overall cognition was negatively correlated with age and positively correlated with VO₂max. VO₂max was a predictor of resting CVC and MAP, and CVC and MAP when end-tidal gases were held constant at near-resting values. MAP and CVC were predictors of cognition. This study identified strong associations between physical fitness, vascular function and cognition, and provides new understanding regarding the mechanisms by which fitness positively impacts cognition with aging. The implications of this research are considerable and warrant future investigation.
authors.affiliation: Department of Physiology & Biophysics, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada.
authors.forename: Allison D
authors.initials: AD
authors.lastname: Brown
authors.forename: Carly A
authors.initials: CA
authors.lastname: McMorris
authors.forename: R Stewart
authors.initials: RS
authors.lastname: Longman
authors.forename: Richard
authors.initials: R
authors.lastname: Leigh
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hill
authors.forename: Christine M
authors.initials: CM
authors.lastname: Friedenreich
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Poulin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology* / Q000517:prevention & control; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D011446:Prospective Studies