title: Physical activity and incident asthma in adults: the HUNT Study, Norway.
abstract: We aimed to investigate the associations of physical activity and change in physical activity with incident asthma in a cohort of Norwegian adults.
  
  
  
  We conducted a prospective cohort study using data on self-reported physical activity from 3 waves of the Nord-Trøndelag Health Study. Physical activity was reported at the first and second surveys (1985-1986 and 1995-1997). Physical activity was defined from the second survey as inactive or active and the active group was further defined as very low, low, moderate and high. Change in physical activity was defined from the first and second surveys.
  
  
  
  A large population-based health survey in Norway.
  
  
  
  We followed 18 894 adults over 11 years who were free from asthma at baseline in 1995-1997.
  
  
  
  Incident asthma was reported in the third survey (2006-2008).
  
  
  
  The cumulative incidence of asthma was 3.6% over the 11 years. The adjusted OR for incident asthma among active participants compared with inactive participants was 0.95 (95% CI 0.69 to 1.34). The adjusted OR for those who were active in the first or second survey versus those who were inactive in both surveys was 0.64 (95% CI 0.34 to 1.38); however, this association was strongly attenuated in sensitivity analysis (OR 0.93, 95% CI 0.38 to 3.09).
  
  
  
  We did not observe statistically significant associations of physical activity or change in physical activity with incident asthma in adults over the 11-year follow-up.
authors.affiliation: Faculty of Medicine, Department of Public Health and General Practice, Norwegian University of Science and Technology, NTNU, Trondheim, Norway.|QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.|Department of Thoracic and Occupational Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Ben M
authors.initials: BM
authors.lastname: Brumpton
authors.affiliation: Faculty of Medicine, Department of Public Health and General Practice, Norwegian University of Science and Technology, NTNU, Trondheim, Norway.
authors.forename: Arnulf
authors.initials: A
authors.lastname: Langhammer
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
authors.forename: Manuel A R
authors.initials: MA
authors.lastname: Ferreira
authors.affiliation: Faculty of Medicine, School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Ottawa, Canada.
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Faculty of Medicine, Department of Public Health and General Practice, Norwegian University of Science and Technology, NTNU, Trondheim, Norway.
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Mai
mesh_terms: D000328:Adult; D001249:Asthma / Q000453:epidemiology*; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D057566:Self Report
keywords: EPIDEMIOLOGY; PUBLIC HEALTH