title: Interaction between asthma and smoking increases the risk of adult airway obstruction.
abstract: The aim of the present study was to analyse the interaction between asthma and smoking in the risk of adult airway obstruction, accounting for atopy. In the European Community Respiratory Health Survey, 15 668 persons aged 20-56 years underwent spirometry in 1991-1993 and 9 years later (n=8916). Risk of airway obstruction and lung function decline associated with smoking and early-onset (<10 years of age) and late-onset (>10 years of age) asthma were analysed with generalised estimating equation models and random-effect linear models, adjusting for covariates. Interaction of asthma with smoking was expressed as relative excess risk due to interaction (RERI). A 20-fold increase in adult airway obstruction was found among those with early-onset asthma independently of smoking status (never-smokers: OR 21.0, 95% CI 12.7-35; current smokers: OR 23.7, 95% CI 13.9-40.6). Late-onset asthma was associated with airway obstruction, with a stronger association among current smokers (OR 25.6, 95% CI 15.6-41.9) than among never-smokers (OR 11.2, 95% CI 6.8-18.6) (RERI 12.02, 95% CI 1.96-22.07). Stratifying by atopy, the association between smoking and asthma was most pronounced among nonatopics. Early- and late-onset asthma were associated with 10-20-fold increased risk of adult airway obstruction. Smoking increased the risk of adult airway obstruction in subjects with asthma onset after age 10 years. Investigation of measures potentially preventive of chronic obstructive pulmonary disease development following asthma is urgently needed.
authors.affiliation: Dept of Medicine, Haukeland University Hospital, Bergen, Norway marianne.aanerud@med.uib.no.
authors.forename: Marianne
authors.initials: M
authors.lastname: Aanerud
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain Hospital del Mar Research Institute (IMIM), Barcelona, Spain.
authors.forename: Anne-Elie
authors.initials: AE
authors.lastname: Carsin
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain Universitat Pompeu Fabra, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Sunyer
authors.affiliation: Institute of Social and Preventive Medicine at the Swiss Tropical Institute, Basel, Switzerland.
authors.forename: Julia
authors.initials: J
authors.lastname: Dratva
authors.affiliation: Dept of Respiratory Medicine and Sleep, Landspitali University Hospital (E7) and Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Gislason
authors.affiliation: Dept of Public Health Sciences, Imperial College, London, UK.
authors.forename: Deborah
authors.initials: D
authors.lastname: Jarvis
authors.affiliation: Dept of Medicine and Public Health/Epidemiology and Medical Statistics, University of Verona, Verona, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: deMarco
authors.affiliation: INSERM, ISPED, Centre INSEM U897, CHU Bordeaux, Bordeaux, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Raherison
authors.affiliation: Helmholtz Center Munich, National Research Centre for Environmental Health, Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Munich, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wjst
authors.affiliation: Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, School of Population Health, The University of Melbourne, Melbourne, Australia.
authors.forename: Shyamali C
authors.initials: SC
authors.lastname: Dharmage
authors.affiliation: Dept of Occupational Medicine, Haukeland University Hospital, Bergen, Norway Centre for International Health, University of Bergen, Bergen, Norway.
authors.forename: Cecilie
authors.initials: C
authors.lastname: Svanes
mesh_terms: D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000402:Airway Obstruction / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D001249:Asthma / Q000150:complications / Q000453:epidemiology / Q000523:psychology; D005060:Europe / Q000453:epidemiology; D005260:Female; D006306:Health Surveys; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology / Q000503:physiopathology