Low postnatal serum IGF-I levels are associated with bronchopulmonary dysplasia (BPD)

Aim: To characterize postnatal changes in serum insulin-like growth factor-1 (IGF-I) in relation to development of bronchopulmonary dysplasia (BPD) in very preterm infants. Methods: Longitudinal study of 108 infants with mean (SD) gestational age (GA) 27.2 (2.2) weeks. Weekly serum samples of IGF-I were analysed from birth until postmenstrual age (PMA) 36 weeks. Multivariate models were developed to identify independent predictors of BPD. Results: Postnatal mean IGF-I levels at postnatal day (PND) 3–21 were lower in infants with BPD compared with infants with no BPD (16 vs. 26 μg/L, p < 0.001). Longitudinal postnatal change in IGF-I levels (IGF-I regression coefficient (β)), PNDs 3–21, was lower in infants with BPD compared with infants with no BPD (0.28 vs. 0.97, p = 0.002) and mean IGF-I during PMA 30–33 weeks was lower in infants with BPD as compared with infants without BPD (22 vs. 29 μg/L, p < 0.001). In a binomial multiple regression model, lower GA, male gender and lower mean serum IGF-I levels during PND 3–21 were the most predictive risk factors associated with BPD (r² = 0.634, p < 0.001). Conclusion: Lower IGF-I concentrations during the first weeks after very preterm birth are associated with later development of BPD.