Bronchopulmonary dysplasia and expiratory airflow at 8 years in children born extremely preterm in the post-surfactant era

Abstract

Background: It is unclear if bronchopulmonary dysplasia (BPD) is independently associated with reduced expiratory airflow at school age. Objective: To determine the independent associations of moderate–severe BPD, mild BPD, gestational age and birth weight z-score with expiratory airflow in children born extremely preterm (EP; 28 days but not at 36 weeks’ postmenstrual age). Expiratory airflow variables, including the forced expired volume in 1 s (FEV1), were measured and values converted to z-scores. Results: Compared with no BPD (n=94), moderate–severe BPD (n=193) was associated with a substantial reduction in expiratory airflow (eg, zFEV1 mean difference −0.69, 95% CI −0.97 to –0.41; ..