Longitudinal Study of the Respiratory Function in Preterm Born Children: Comparison Between Subjects with and without Bronchopulmonary Dysplasia

Abstract The long-term changes of the respiratory function in patients with broncho-pulmonary dysplasia (BPD) are still largely unknown. Aim: To study longitudinally the lung function of patients with BPD approaching the adulthood, compared with preterm born subjects without BPD (non-BPD). Methods: 23 preterm born subjects with a gestational age of 23 ± 3 weeks and birth weight of 1296 ± 543 gr were studied and divided in two groups, one with BPD (n = 13) and one without BDP (n = 10) according to the Shennan definition and then reclassified following the definition NICHHD (n = 16 BPD and n = 7 non-BPD). Pulmonary function testing was performed at age of 9.2 ± 2.2 yr (T1) and 15.2 ± 2.3 yr (T2). The two groups were compared both at T1 and T2 and changes from T1 and T2 were assessed in both groups. Results: The functional parameters of the non-BPD subjects were in the normal range at T1, except FEF25-75% that, however, showed a tendency towards the normality at T2. The BPD patients had mild airflow obstruction, mainly localized in the small airways, with marked air trapping at T1. A significant improvement of lung volumes and maximal expiratory flows was observed at T2. Conclusions: The presence of BPD was associated with an obstructive ventilatory defect at age 9, substantially involving the peripheral airways that still persisted at age 15, although with a lesser degree of severity.