title: Regular physical activity modifies smoking-related lung function decline and reduces risk of chronic obstructive pulmonary disease: a population-based cohort study.
abstract: BACKGROUND
  We have previously reported that regular physical activity reduces risk of chronic obstructive pulmonary disease (COPD) exacerbation. We hypothesized that higher levels of regular physical activity could reduce the risk of COPD by modifying smoking-related lung function decline.
  
  
  OBJECTIVE
  To estimate the longitudinal association between regular physical activity and FEV(1) and FVC decline and COPD risk.
  
  
  METHODS
  A population-based sample (n = 6,790) was recruited and assessed with respect to physical activity, smoking, lung function, and other covariates, in Copenhagen in 1981-1983, and followed until 1991-1994. Mean level of physical activity between baseline and follow-up was classified into "low," "moderate," and "high." FEV(1) and FVC decline rates were expressed as milliliters per year. COPD was defined as FEV(1)/FVC < or = 70%. Adjusted associations between physical activity and FEV(1) and FVC decline, and COPD incidence, were obtained using linear and logistic regression, respectively.
  
  
  RESULTS
  Active smokers with moderate and high physical activity had a reduced FEV(1) and FVC decline compared with those with low physical activity (relative change of +2.6 and +4.8 ml/yr of FEV(1), P-for-trend = 0.006, and +2.6 and +7.7 ml/yr of FVC, P-for-trend < 0.0001, for the moderate and high physical activity group, respectively), after adjusting for all potential confounders and risk factors of lung function decline. Active smokers with moderate to high physical activity had a reduced risk of developing COPD as compared with the low physical activity group (odds ratio, 0.77; p = 0.027).
  
  
  CONCLUSIONS
  This prospective study shows that moderate to high levels of regular physical activity are associated with reduced lung function decline and COPD risk among smokers.
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Institut Municipal d'Investigació Mèdica (IMIM), Doctor Aiguader 88, 08003 Barcelona, Catalonia, Spain. jgarcia@imim.es
authors.forename: Judith
authors.initials: J
authors.lastname: Garcia-Aymerich
authors.forename: Peter
authors.initials: P
authors.lastname: Lange
authors.forename: Marta
authors.initials: M
authors.lastname: Benet
authors.forename: Peter
authors.initials: P
authors.lastname: Schnohr
authors.forename: Josep M
authors.initials: JM
authors.lastname: Antó
mesh_terms: D000203:Activities of Daily Living; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D011159:Population Surveillance; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000453:epidemiology / Q000517:prevention & control*; D012129:Respiratory Function Tests; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000503:physiopathology; D013997:Time Factors; D014505:Urban Population