title: Adiposity, asthma, and airway inflammation.
abstract: BACKGROUND
  Several studies have found obesity to be associated with an increased prevalence of asthma. For reasons that remain unclear, this association has often been reported to be stronger in women than in men. One possible explanation might be that these studies have used body mass index to identify adiposity, which might be a less reliable measure of body fat in men than in women.
  
  
  OBJECTIVE
  We sought to explore the association between body fat percentage measured by means of bioelectrical impedance analysis and asthma, airflow obstruction, and airway inflammation in men and women.
  
  
  METHODS
  Respiratory questionnaires, spirometry, bronchodilator response, exhaled nitric oxide level, and percentage of body fat were measured in a population-based cohort of approximately 1000 individuals at age 32 years.
  
  
  RESULTS
  There was a significant association between the percentage of body fat and asthma in women (P = .043) but not in men (P = .75). Airflow obstruction was associated with percentage of body fat in women (P = .046), but there was an inverse association in men (P = .010). Bronchodilator responsiveness was also associated with lower body fat in men (P = .004). Airway inflammation, measured by means of exhaled nitric oxide, was not associated with body fat in either women (P = .17) or men (P = .25).
  
  
  CONCLUSIONS
  Adiposity is associated with asthma and airflow obstruction in women. This does not appear to be mediated by airway inflammation. In men airflow obstruction and bronchodilator responsiveness are associated with a lower percentage of body fat.
  
  
  CONCLUSIONS
  In women, but not in men, obesity is associated with asthma and airflow obstruction, but there was no association with airway inflammation.
authors.affiliation: Dunedin Multidisciplinary Health and Development Research Unit, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: Christene R
authors.initials: CR
authors.lastname: McLachlan
authors.forename: Richie
authors.initials: R
authors.lastname: Poulton
authors.forename: George
authors.initials: G
authors.lastname: Car
authors.forename: Jan
authors.initials: J
authors.lastname: Cowan
authors.forename: Susan
authors.initials: S
authors.lastname: Filsell
authors.forename: Justina M
authors.initials: JM
authors.lastname: Greene
authors.forename: D Robin
authors.initials: DR
authors.lastname: Taylor
authors.forename: David
authors.initials: D
authors.lastname: Welch
authors.forename: Avis
authors.initials: A
authors.lastname: Williamson
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Sears
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hancox
mesh_terms: D000273:Adipose Tissue; D050154:Adiposity; D000328:Adult; D000402:Airway Obstruction / Q000453:epidemiology*; D001249:Asthma / Q000453:epidemiology*; D015992:Body Mass Index; D001980:Bronchi / Q000187:drug effects / Q000503:physiopathology; D001991:Bronchitis / Q000453:epidemiology*; D001993:Bronchodilator Agents / Q000494:pharmacology; D002000:Bronchospirometry; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000150:complications* / Q000175:diagnosis; D011795:Surveys and Questionnaires
chemical_list: D001993:Bronchodilator Agents