title: Incidence of asthma and net change in symptoms in relation to changes in obesity.
abstract: The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males.
authors.affiliation: Respiratory Epidemiology and Public Health Group, Imperial College London, London, UK. sue.chinn@kcl.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Chinn
authors.forename: S H
authors.initials: SH
authors.lastname: Downs
authors.forename: J M
authors.initials: JM
authors.lastname: Anto
authors.forename: M W
authors.initials: MW
authors.lastname: Gerbase
authors.forename: B
authors.initials: B
authors.lastname: Leynaert
authors.forename: R
authors.initials: R
authors.lastname: de Marco
authors.forename: C
authors.initials: C
authors.lastname: Janson
authors.forename: D
authors.initials: D
authors.lastname: Jarvis
authors.forename: N
authors.initials: N
authors.lastname: Künzli
authors.forename: J
authors.initials: J
authors.lastname: Sunyer
authors.forename: C
authors.initials: C
authors.lastname: Svanes
authors.forename: E
authors.initials: E
authors.lastname: Zemp
authors.forename: U
authors.initials: U
authors.lastname: Ackermann-Liebrich
authors.forename: P
authors.initials: P
authors.lastname: Burney
mesh_terms: D000328:Adult; D001249:Asthma / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology; D015992:Body Mass Index; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D013557:Switzerland / Q000453:epidemiology