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.