Risk factors for incident asthma and COPD in a cohort of young adults

INTRODUCTION: The aim of the study was to describe potential shared risk factors for incident asthma and COPD in a population-based, nine-year follow-up study.

METHODS: From a cohort of 1,191 individuals, aged 20-44, who participated in baseline survey including spirometry, bronchial challenge, and skin prick test (SPT) 742 subjects (62%) were reexamined at follow-up in 2012-2014.

RESULTS: A total of 27 incident cases of asthma and 22 cases of COPD were identified at follow-up corresponding to an incidence rate of 5.8 (95% CI 3.9-8.4) and 3.5 (2.2-5.3) per 1,000 person years, respectively. Among the identified COPD cases a total of 12 were Asthma-COPD Overlap Syndrome (ACOS). Atopy defined by positive SPT was a risk factor for asthma in males (OR 7.54; 95% CI 1.24-45.90), whereas risk factors in females were nasal allergy (3.81; 1.20-12.11), FEV1 <100% predicted (3.96; 1.07-14.62) and parental asthma (3.06; 1.00-9.40). Risk factors for COPD in males were bronchial hyperresponsiveness (23.13; 1.41-380.50) and FEV1 <100% predicted (all male cases had FEV1 <100% predicted) and in females current smoking (3.34; 1.16-9.59) and asthma at baseline (5.21; 1.48-18.34).

CONCLUSIONS: No shared risk factors for incident asthma and COPD were found. Despite low power when stratifying by sex risk factors for incident asthma and COPD emphasise considerable gender differences. This article is protected by copyright. All rights reserved.