title: Cardiorespiratory fitness as a predictor of dementia mortality in men and women.
abstract: There is evidence that physical activity may reduce the risk of developing Alzheimer disease and dementia. However, few reports have examined the physical activity-dementia association with objective measures of physical activity. Cardiorespiratory fitness (hereafter called fitness) is an objective reproducible measure of recent physical activity habits.
  
  
  OBJECTIVE
  We sought to determine whether fitness is associated with lower risk for dementia mortality in women and men.
  
  
  METHODS
  We followed 14,811 women and 45,078 men, age 20-88 yr at baseline, for an average of 17 yr. All participants completed a preventive health examination at the Cooper Clinic in Dallas, TX, during 1970-2001. Fitness was measured with a maximal treadmill exercise test, with results expressed in maximal METs. The National Death Index identified deaths through 2003. Cox proportional hazards models were used to examine the association between baseline fitness and dementia mortality, adjusting for age, sex, examination year, body mass index, smoking, alcohol use, abnormal ECGs, and health status.
  
  
  RESULTS
  There were 164 deaths with dementia listed as the cause during 1,012,125 person-years of exposure. Each 1-MET increase in fitness was associated with a 14% lower adjusted risk of dementia mortality (95% confidence interval (CI) = 6%-22%). With fitness expressed in tertiles, adjusted hazard ratios (HRs) for those in the middle- and high-fitness groups suggest their risk of dementia mortality was less than half that of those in the lowest fitness group (HR = 0.44, CI = 0.26-0.74 and HR = 0.49, CI = 0.26-0.90, respectively).
  
  
  CONCLUSIONS
  Greater fitness was associated with lower risk of mortality from dementia in a large cohort of men and women.
authors.affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA. liur2@niehs.nih.gov
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.forename: Xuemei
authors.initials: X
authors.lastname: Sui
authors.forename: James N
authors.initials: JN
authors.lastname: Laditka
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Church
authors.forename: Natalie
authors.initials: N
authors.lastname: Colabianchi
authors.forename: Jim
authors.initials: J
authors.lastname: Hussey
authors.forename: Steven N
authors.initials: SN
authors.lastname: Blair
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D002908:Chronic Disease; D015140:Dementia, Vascular / Q000401:mortality* / Q000503:physiopathology*; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006304:Health Status; D006801:Humans; D008055:Lipids / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness; D012306:Risk; D012907:Smoking / Q000453:epidemiology; D055815:Young Adult
chemical_list: D008055:Lipids