title: Asthma, COPD and overlap syndrome: a longitudinal study in young European adults.
abstract: We compared risk factors and clinical characteristics, 9-year lung function change and hospitalisation risk across subjects with the asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS), asthma or COPD alone, or none of these diseases.Participants in the European Community Respiratory Health Survey in 1991-1993 (aged 20-44 years) and 1999-2001 were included. Chronic airflow obstruction was defined as pre-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity<lower limit of normal on both occasions. Based on their history of respiratory symptoms, spirometry and risk factors, subjects were classified as having asthma alone (n=941), COPD alone (n=166), ACOS (n=218) and none of these (n=5659).Subjects with ACOS shared risk factors and clinical characteristics with subjects with asthma alone, but they had an earlier age of asthma onset. FEV1 change in the ACOS group (-25.9 mL·year(-1)) was similar to that in the asthma group (-25.3 mL·year(-1)), and lower (p<0.001) than in the COPD group (-37.3 mL·year(-1)). ACOS was associated with the highest hospitalisation rate.Among young adults aged 20-44 years, ACOS seems to represent a form of severe asthma, characterised by more frequent hospitalisations, and to be the result of early-onset asthma that has progressed to fixed airflow obstruction.
authors.affiliation: Unit of Epidemiology and Medical Statistics, Department of Public Health and Community Medicine, University of Verona, Verona, Italy roberto.demarco@univr.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: de Marco
authors.affiliation: Unit of Epidemiology and Medical Statistics, Department of Public Health and Community Medicine, University of Verona, Verona, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marcon
authors.affiliation: Pulmonary Unit, Azienda Ospedaliera Universitaria Integrata and University of Verona, Verona, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Rossi
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain Hospital del Mar Medical Research Institute, Barcelona, Spain Universitat Pompeu Fabra, Barcelona, Spain CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Antó
authors.affiliation: Istituto di Ricovero e Cura a Carattere Scientifico San Matteo Hospital Foundation, University of Pavia, Pavia, Italy.
authors.forename: Isa
authors.initials: I
authors.lastname: Cerveri
authors.affiliation: Department of Respiratory Medicine and Sleep, Landspitali University Hospital and Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Gislason
authors.affiliation: Institute of Epidemiology I, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Munich, Germany Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, Inner City Clinic, University Hospital of Munich, Ludwig-Maximilians University (LMU), Munich, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Heinrich
authors.affiliation: Department of Medical Sciences: Respiratory Medicine and Allergology, Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Christer
authors.initials: C
authors.lastname: Janson
authors.affiliation: Respiratory Epidemiology and Public Health Group, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Deborah
authors.initials: D
authors.lastname: Jarvis
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland University of Basel, Basel, Switzerland.
authors.forename: Nino
authors.initials: N
authors.lastname: Kuenzli
authors.affiliation: Inserm-U1152-Epidemiology, Institut National de la Santé et de la Recherche Médicale, Faculté Paris Diderot, Paris, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Leynaert
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland University of Basel, Basel, Switzerland.
authors.forename: Nicole
authors.initials: N
authors.lastname: Probst-Hensch
authors.affiliation: Bergen Respiratory Research Group, Centre for International Health, University of Bergen, Bergen, Norway Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Cecilie
authors.initials: C
authors.lastname: Svanes
authors.affiliation: Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Munich, Germany Institute of Medical Statistics and Epidemiology, Technische Universitaet Muenchen, Munich, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wjst
authors.affiliation: Respiratory Epidemiology and Public Health Group, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Burney
mesh_terms: D000328:Adult; D017677:Age Distribution; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D012008:Recurrence; D012129:Respiratory Function Tests; D018570:Risk Assessment; D017678:Sex Distribution; D013147:Spirometry; D015996:Survival Rate; D013577:Syndrome; D014797:Vital Capacity / Q000502:physiology*; D055815:Young Adult