Infant bronchiolitis increases the risk of reduced lung function at age 10-13 years

Abstract

Background: Infant bronchiolitis may lead to lung function reduction. However, reversibility of changes in lung function is less studied in adolescents after infant bronchiolitis. Methods: The aim of this study was to evaluate baseline and post-bronchodilator lung function at the age of 10-13 years after bronchiolitis in early infancy, with special focus on the RSV aetiology. Flow-volume spirometry with bronchodilation test was measured in 89 cases with early-life bronchiolitis and 108 controls without history of bronchiolitis at the mean age of 11.7 years. Parameters of flow-volume spirometry were analysed as sex-specific height-related %of-predicted values. We hypothesized that bronchiolitis in early infancy is associated with reduced lung function in early adolescence. Results: As continuous variables, forced expiratory volume in 1 sec/forced vital capacity (FEV1/FVC) after bronchodilation was lower in cases than controls. As categorised variables, FEV1 was pathological (under the 5th percentile of the national references) in 25% of cases before bronchodilation (controls 12%, p=0.020), in 18% of cases after bronchodilation (controls 5%, p=0.003), and FEV1/FVC was pathological in 25% of cases before bronchodilation (controls 13%, p=0.034). In the adjusted logistic regression, infant bronchiolitis was associated with pathological FEV1 before (odds ratio 2.4) and after (odds ratio 4.4) bronchodilation. The result was similar in RSV positive cases. Conclusions: Evidence of reduced FEV1 before and after bronchodilation was found at 10-13 years of age after infant bronchiolitis suggesting an irreversible bronchial obstruction.