P2 The effect of postnatal steroid exposure on the lung function of prematurely born young people

Aims Postnatal steroid exposure has been shown to negatively influence fetal lung growth in animal models and be associated with poor lung function in prematurely born children aged 11 to 14 years. Whether the poorer lung function persists after puberty is not known. Hence, our aim was to investigate the effects of postnatal steroid exposure on the lung function of prematurely born young people at age 16 to 19 years who had been routinely exposed to antenatal corticosteroids and postnatal surfactant. Methods Young people recruited into the United Kingdom Oscillation Study were invited for follow-up. Assessments included; forced expired volumes at 1 s (FEV1), forced vital capacity (FVC), forced expiratory flow at 25%, 50%, 75% and between 25%–75% of FVC (FEF25, 50, 75, 25–75), functional residual capacity by plethysmography (FRCpleth), diffusion capacity of the lungs for carbon monoxide (DLCO) and lung clearance index (LCI). Exercise capacity was assessed using a modified shuttle walk test and by self-assessment. Results The median age at assessment was 18 (range 16–19) years, weight 61 (30–114) kg and height 169 (150–189) cm. Their median gestational age was 27 (24–29) weeks and birthweight 883 (454–1360) g. There was no difference in current or past asthma between the groups (p=0.751 and p=0.540 respectively). Lung function differences and exercise data are shown below, table 1. Conclusion Postnatal steroid exposure in very prematurely born young people was associated with significantly poorer lung function and reduced exercise capacity post puberty.