Background: Bronchopulmonary Dysplasia (BPD) has many causes, possibly including immature antioxidant defences. We hypothesised that antioxidant Vitamins A and E and Selenium levels would be low in very low birth weight (VLBW: <1500 g) infants at birth, and would remain low in those developing BPD and rise in those with less oxidant stress.
Methods: Case-control study of 28 babies who developed BPD and 28 birth weight (BW) and gestational age (GA) matched controls who did not develop BPD, all from a larger group of 125 VLBW infants who had prospective measurement of plasma vitamin A (Vit A), vitamin E (Vit E) and Selenium (Se) taken on days 1, 14, 28 and 42 of life. Analysis was by repeated measures ANOVA, and results expressed as means with the BPD group first in all cases.
Results: There were no significant differences in GA (26.4 weeks in both), BW (880 g or 867 g) or Vit A and Vit E intakes. Vit A, Vit E and Se levels were similar at birth, but were higher in the BPD group with time(p=0.34, p=0.0005 and p=0.004 respectively as measured by ANOVA with time). In a post-hoc analysis to evaluate a possible effect of corticosteroids, we found significant differences (p<0.0001) in percentage treated with postnatal steroids (86% and 32%) and duration of steroids (35 and 4 days).
Conclusions: Our hypothesis was not supported. Both groups had considerable oxidant stress, with no difference in Vitamin intake, but there was an association between increased antioxidant levels and BPD with time. We suggest that postnatal steroids may have caused this increase in antioxidant levels in babies who developed BPD.
(Spon by: Arne Ohlsson)