The predictive value of cord blood 25-hydroxyvitamin D and vitamin A levels for bronchopulmonary dysplasia in preterm infants

Background: Despite considerable advances in therapeutic approaches for bronchopulmonary dysplasia (BPD), its incidence remains persistently high, with a troubling rise in moderate-to-severe cases. Given the progressive nature and clinical burden of BPD, identifying early diagnostic biomarkers is essential for implementing timely, individualized therapeutic interventions and improving long-term outcomes. Methods: This prospective cohort study included 144 preterm infants (gestational age ≤32 weeks) . Umbilical artery blood samples were collected to measure levels of Interleukin-6 (IL-6) , C-reactive protein(CRP), Procalcitonin (PCT), 25- hydroxyvitamin D [25(OH)D], and vitamin A (VA）. Infants were classified as either BPD (n = 63) or non-BPD (control group, n = 81). Based on oxygen dependency and respiratory support criteria, BPD cases were categorized into BPD severity stages: I (n = 34), II (n = 17), and III (n = 12) , identify BPD risk factors, univariate analysis was conducted, and ROC curve analysis was carried out to determine the predictive value of 25(OH)D and VA. Results: Levels of 25(OH)D and VA were significantly reduced, while PCT was elevated in the BPD group compared to controls. Among the different grades of BPD severity, 25(OH)D levels were lower and IL-6 levels higher in grade III compared to grade I, while PCT levels were elevated in grade II relative to grade I. Univariate analysis identified birth weight, gestational age, birth asphyxia, placental abnormalities, pulmonary surfactant use, caffeine therapy, and mechanical ventilation duration as independent risk factors for BPD. ROC analysis showed that 25(OH)D predicted BPD with 90.48% sensitivity, 69.14% specificity, 90.32% negative predictive value (NPV), and 69.51% positive predictive value (PPV), outperforming VA (77.77%, 54.32%, 75.86%, and 56.98%, respectively). Combined detection of VA and 25(OH)D yielded 57.14% sensitivity, 77.77% specificity, 70.00% NPV, and 66.67% PPV, indicating no significant improvement in predictive performance. Conclusion: Umbilical cord blood 25(OH)D and VA levels may serve as useful biomarkers for BPD risk assessment in preterm infants. Notably, 25(OH)D demonstrated high sensitivity and an inverse correlation with BPD severity, supporting its role in early risk stratification, whereas its combination with VA did not enhance predictive accuracy, underscoring the need for a multidimensional predictive approach.