title: Light-Intensity Physical Activity and All-Cause Mortality.
abstract: OBJECTIVE
  Research demonstrates that moderate-to-vigorous physical activity (MVPA) is associated with a reduced risk of all-cause mortality. Few studies have examined the effects of light-intensity physical activity on mortality. Therefore, the purpose of this study was to examine the association between objectively measured light-intensity physical activity and all-cause mortality risk.
  
  
  METHODS
  Longitudinal.
  
  
  METHODS
  National Health and Nutrition Examination Survey 2003-2006 with follow-up through December 31, 2011.
  
  
  METHODS
  Five thousand five hundred seventy-five U.S. adults.
  
  
  METHODS
  Participants wore an accelerometer for at least 4 days and completed questionnaires to assess sociodemographics and chronic disease information, with blood samples taken to assess biological markers. Follow-up mortality status was assessed via death certificate data from the National Death Index.
  
  
  METHODS
  Cox proportional hazard model.
  
  
  RESULTS
  After adjusting for accelerometer-determined MVPA, age, gender, race-ethnicity, cotinine, weight status, poverty level, C-reactive protein, and comorbid illness, for every 60-minute increase in accelerometer-determined light-intensity physical activity, participants had a 16% reduced hazard of all-cause mortality (hazard ratio = .84; 95% confidence interval: .78-.91; p < .001).
  
  
  CONCLUSIONS
  In this national sample of U.S. adults, light-intensity physical activity was inversely associated with all-cause mortality risk, independent of age, MVPA, and other potential confounders. In addition to MVPA, promotion of light-intensity physical activity is warranted.
authors.affiliation: 1 Center for Health Behavior Research, School of Applied Sciences, Department of Health, Exercise Science, and Recreation Management, The University of Mississippi, University, Mississippi.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Loprinzi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D002097:C-Reactive Protein; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009749:Nutrition Surveys; D057185:Sedentary Behavior; D012959:Socioeconomic Factors; D014481:United States; D055815:Young Adult
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein
keywords: Accelerometry, Chronic Disease, Epidemiology, Exercise, Mortality, National Health and Nutrition Examination Survey (NHANES), Prevention Research. Manuscript format: research; Health focus: physical activity; Outcome measure: mortality; Research purpose: modeling/relationship testing; Setting: national; Strategy: education, behavior change; Study design: longitudinal; Target population age: adults; Target population circumstances: education