Reduced airway function in early adulthood among subjects with wheezing disorder before two years of age

Aim: To compare airway function in early adulthood in subjects with wheezing in infancy with age-matched controls and to analyze what accounts for a possible difference. Methods: Asthma development has been prospectively studied in 101 children hospitalized due to wheezing before the age of two. The cohort was re-investigated at age 17-20 years and tested with spirometry and for bronchial hyper-responsiveness and allergic sensitization. An age-matched population (n = 294) was used for comparison. Results: The cohort had a significantly lower FEV1/FVC ratio and MEF50, both pre- and post-bronchodilation, compared with the controls, P < 0.01. The reduction in airway function was most evident in current asthmatic female subjects, but a reduced pre-bronchodilation FEV1/FVC ratio was also seen in symptom-free cohort subjects, P = 0.03. In the multivariate analysis, female gender was the most prominent independent risk factor for reduced airway function in early adulthood, pre-bronchodilation OR 4.0 (1.4-11.3) and post-bronchodilation OR 8.8 (1.8-42.0). In addition, a history of early wheezing, that is, belonging to the cohort, was an independent risk factor for reduced airway function pre-bronchodilation, OR 3.3 (1.3-8.7). Furthermore, there was an association between current bronchial hyper-responsiveness and an increased risk of reduced airway function post-bronchodilation, OR 7.3 (2.0-26.6). Conclusion: Reduced airway function in early adulthood was found in subjects with wheezing early in life, compared with age-matched controls. The reduction was most prominent in females with current asthma.