title: Combined associations of sedentary behavior and cardiorespiratory fitness on cognitive function among older adults.
abstract: BACKGROUND
  Sedentary behavior, cardiorespiratory fitness, cognition and age are interrelated and associated with cardiovascular function. No study, however, has specifically evaluated the independent and combined associations of cardiorespiratory fitness and sedentary behavior on cognition, which was this study's purpose.
  
  
  METHODS
  Data from the 1999-2002 NHANES were used (N=2451; 60-85yrs). Sedentary behavior was assessed via self-report; cardiorespiratory fitness was assessed from a medical-related algorithm; and cognition function was assessed from the Digit Symbol Substitution Test (DSST).
  
  
  RESULTS
  Being in the bottom quartile for sedentary behavior (β=2.13; 95% CI: 0.49-3.77; P=0.01) and the top quartile for cardiorespiratory fitness (β=7.48; 95% CI: 5.4-9.5; P<0.001) were independently associated with higher cognitive function. In the additive model, those with an index score of 1 (vs. 0) and 2 (vs. 0), respectively, had a 3.87 (β=3.87; 95% CI: 1.76-5.98; P=0.001) and 10.40 (β=10.4; 95% CI: 7.31-13.5; P<0.001) higher DSST score.
  
  
  CONCLUSIONS
  High cardiorespiratory fitness and low sedentary behavior were jointly associated with the highest cognitive function. This has important cardiovascular implications as a progression of neurocognitive impairment is associated with increasingly severe manifestations of cardiovascular disease.
authors.affiliation: Physical Activity Epidemiology Laboratory, Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS 38677, United States.
authors.forename: Meghan K
authors.initials: MK
authors.lastname: Edwards
authors.affiliation: Jackson Heart Study Vanguard Center of Oxford, Physical Activity Epidemiology Laboratory, Department of Health, Exercise Science and Recreation Management, The University of Mississippi, University, MS 38677, United States. Electronic address: pdloprin@olemiss.edu.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Loprinzi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000072599:Cardiorespiratory Fitness / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000503:physiopathology / Q000517:prevention & control* / Q000523:psychology; D003071:Cognition / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D012189:Retrospective Studies; D057185:Sedentary Behavior
keywords: Cardiorespiratory fitness; Cognitive function; Epidemiology; Sedentary behavior