Lung function and bronchial hyper‐reactivity from 11 to 18 years in children with bronchiolitis in infancy

Background Various trajectories for lung function and bronchial hyper‐reactivity (BHR) from early childhood to adulthood are described, including puberty as a period with excessive lung growth. Bronchiolitis in infancy may be associated with increased risk of developing chronic obstructive pulmonary disease, but the development of respiratory patterns during puberty is poorly characterized for these children. We aimed to study the development and trajectories of lung function and BHR from 11 to 18 years of age in children hospitalized for bronchiolitis in infancy. Methods Infants hospitalized for bronchiolitis at the University Hospitals in Stavanger and Bergen, Norway, during 1997‐1998, and an age‐matched control group, were included in a longitudinal follow‐up study and examined at 11 and 18 years of age with spirometry and methacholine provocation test (MPT). The MPT data were managed as dose‐response slope (DRS) in the statistical analyses. Changes in lung function and DRS from 11 to 18 years of age were analyzed by generalized estimating equations, including interaction terms. Results z‐scores for forced vital capacity (FVC), forced expiratory volume in first second (FEV1), FEV1/FVC ratio, and DRS were not different from 11 to 18 years of age in both the post‐bronchiolitis and the control group. The trajectories from 11 to 18 years did not differ between the two groups. BHR at age 11 was independently associated with asthma at age 18. Conclusion Children hospitalized for bronchiolitis had stable predicted lung function and BHR from 11 to 18 years of age. The lung function trajectories were not different from controls.