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% (FEF_25-75 ) (-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.

Keywords: biological sex; exercise capacity; preterm.