Lung function at 16–19 years in males and females born very prematurely

Abstract

Objectives: To determine if there were differences in lung function at 16–19 years of age between males and females born very prematurely. Working Hypothesis: Females compared with males would have superior lung function and exercise capacity. Study Design: Cohort study. Patient-Subject Selection: Those born at less than 29 weeks of gestational age. Methodology: Lung function testing (spirometry, oscillometry, diffusion capacity, lung clearance index, and plethysmography), a shuttle sprint test for exercise capacity, and a respiratory symptoms questionnaire. Results: Amongst 150 participants, males had poorer lung function compared with females with mean z score differences (95% CI [confidence interval]) after adjustment: forced expiratory flow at 75% (FEF75) (–0.60 [–0.97,–0.24]), forced expiratory flow at 50% (FEF50) (−0.39 [−0.72,−0.07]), forced expiratory flow at 25%–75% (FEF25-75) (−0.62 [−0.98,−0.26]), the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs (FEV1:FVC ratio) (−0.71 [−1.09,−0.34]), diffusing capacity of the lungs for carbon monoxide (DLCO) (−0.41 [−0.78,−0.03]), diffusing capacity of the lung for carbon monoxide divided by alveolar volume (DLCO/VA) (−0.57 [−0.86,−0.28]). Exercise capacity and self-reported exercise were both significantly better in males than females (46% males achieving between 1250 and 1500 m shuttle sprint distance vs. 4.8% females) and 74% males versus 67% females undertaking some exercise. There were no significant differences by sex in the prevalence of either wheeze or current asthma. Conclusions: Males had poorer lung function than females at age 16–19 years, but their exercise capacity was superior to females.