LATE-BREAKING ABSTRACT: Evaluation of lung function in BPD survivors from infancy to adulthood: The Padova BPD study

Abstract

Background. Few studies have prospectively followed respiratory function of bronchopulmonary dysplasia (BPD) survivors from infancy to adult age. Objectives. This study was conducted from March 1991 to March 2016 to longitudinally investigate the evolution of lung function in 17 survivors of BPD (birth weight Methods. Maximum flow at functional residual capacity(VmaxFRC ) at 2 years (yrs), and lung function(FEV 1, FVC and FEF 25-75 ) at ages 9, 15, 20 and 24 yrs were obtained for each subject. Repeated measures analysis of variance ANOVA, t test, and linear regression were used for data analysis. Results. Survivors of BPD showed a consistent lung function tracking from 2 years till 24 years of age. No significant change in mean z-score emerged between expiratory flow measures at ages 2 years(zVmaxFRC -1.48, SD 1.38), 9 yrs (zFEV 1 -1.74, SD 1.03), 15 yrs (zFEV 1 -1.71, SD 1.72), 20 yrs (zFEV 1 -1.73, SD 1.65) and 24 yrs(zFEV 1 -2.14, SD 1.74)(P=0.42). Mean z-scores for FVC and FEF 25-75 did not change significantly between different ages as well(P>0.5 and P=0.45 respectively). A significant correlation was found between the z-scores for VmaxFRC at 2 years and the z-scores for FEV 1 at ages 15 yrs(r=0.74, P=0.001), 20 yrs(r=0.75, P 1 ≥12%) was observed in 23.5% of subjects. Comment . Our findings show that BPD survivors present a tracking of lung function until adulthood, with flow limitation still persisting at 24 years of age. Reduced expiratory flow at 2 years identifies patients at greater risk of developing a COPD-like phenotype at adult age.