title: Increased daily movement associates with reduced mortality among COPD patients having systemic inflammation.
abstract: BACKGROUND
  Emerging research demonstrates an interrelationship between systemic inflammation, physical activity and premature all-cause mortality among chronic obstructive pulmonary disease (COPD) patients. Less common in this literature is the use of objective measures of physical activity and representative samples of COPD patients.
  
  
  OBJECTIVE
  To examine the association between objectively measured physical activity and all-cause mortality among a national sample of COPD patients, with stratification by inflammatory status.
  
  
  METHODS
  Data from the 2003 to 2006 NHANES were employed, with follow-up through 2011. Physical activity was objectively measured via accelerometry; COPD was assessed via physician-diagnosis; and inflammation was assessed via C-reactive protein (CRP) levels from a blood sample.
  
  
  RESULTS
  Analysis included 385 adults (20+ years) with COPD. The median follow-up period was 78 months (IQR = 64-90), with 82 COPD patients dying during this period. After adjustment, physical activity was not associated with all-cause mortality among the entire sample (HR = 0.80; 95% CI: 0.61-1.05) or those with no systemic inflammation (HR = 0.89; 95% CI: 0.63-1.24). However, for every 60 min increase in physical activity per day, COPD patients with elevated CRP had a 31% reduced risk of all-cause mortality (HR = 0.69; 95% CI: 0.51-0.93).
  
  
  CONCLUSIONS
  Physical activity may help to promote survival among COPD patients, particularly those with elevated inflammation.
authors.affiliation: Department of Health, Exercise Science and Recreation Management, Center for Health Behavior Research, The University of Mississippi, University, MS, USA.
authors.forename: P D
authors.initials: PD
authors.lastname: Loprinzi
authors.affiliation: Department of Respiratory Therapy, Bellarmine University, Louisville, KY, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Walker
mesh_terms: D061725:Accelerometry; D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology / Q000401:mortality; D012307:Risk Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology
chemical_list: D002097:C-Reactive Protein