Background and aims Vitamin D is considered as an important regulator of fetal lung development and innate immune system. Its functions involved in susceptibility and resistance to infections and pulmonary diseases may be important for the occurrence of bronchopulmonary dysplasia (BPD). The aim of the study was to investigate the relationship between Vitamin D receptor gene polymorphism and BPD in preterm infants.
Methods Fok I, Bsm I, Apa I, and Taq I polymorphisms in the Vitamin D Receptor (VDR) gene were genotyped using restriction fragment length polymorphism in109 preterm infants (47 with BPD, 62 without BPD) born at gestational age ≤ 32 weeks and admitted to NICU at Ege University Hospital.
Results The univariate analysis showed Ff (OR=3.937, p=0.022, 95% CI= 1.22–12.69) and ff (OR=5.238, p=0.004, 95% CI= 1.69–16.23) genotypes of Fok I polymorphism were associated with increased risk of BPD; whereas tt genotype of Taq 1 polymorphism; was associated with a protective effect against BPD (OR=0.30, p=0.04, 95% CI= 0.098–0.094). In a multivariate logistic regression analysis of the model including variant Fok1 genotype with significant PDA, clinical and culture proven sepsis, mechanical ventilation and surfactant treatment; variant Fok 1 genotype increased the risk of BPD (OR=4.115, CI=1.080–15.686, p=0.038) independent from these factors. Taq 1, Bsm 1 and Apa 1 polymorphisms did not have any effect in the same model.
Conclusion Fok1 polymorphism was associated with increased frequency of BPD after adjusting for multiple confounders. VDR gene polymorphisms may be suitable for prediction of infants at high risk for BPD.