Biomarkers of cardiac injury in infants of diabetic mothers and its relation to echocardiographic findings

Infants of diabetic mothers (IDMs) are predisposed to transient hypertrophic cardiomyopathy and subclinical myocardial dysfunction. However, validated diagnostic cut-off values for cardiac biomarkers in this population are lacking, and the relationship between a panel of multiple biomarkers and advanced echocardiographic indices has not been systematically established. This study aimed to evaluate cardiac troponin-I (cTnI), B-type natriuretic peptide (BNP), and creatine kinase-MB (CK-MB) in IDMs, correlate them with conventional and advanced echocardiographic parameters, and derive ROC-based diagnostic cut-off values for detecting echocardiographically defined cardiac dysfunction. In this prospective cross-sectional study, 100 term IDMs and 50 healthy controls were enrolled. Maternal glycemic control was assessed using HbA1c. Neonatal serum cTnI, BNP, and CK-MB were measured within 24–48 h of birth. Comprehensive echocardiography included M-mode measurements, left ventricular mass (Devereux formula), fractional shortening, myocardial performance index (pulsed-wave tissue Doppler at the lateral mitral annulus), E/A ratio, and E/E′ ratio. ROC analysis determined optimal diagnostic cut-offs. IDMs had significantly higher cTnI (0.42 ± 0.18 vs. 0.09 ± 0.03 ng/mL), BNP (165 ± 60 vs. 60 ± 20 pg/mL), and CK-MB (85 ± 25 vs. 45 ± 18 U/L) compared to controls (all p < 0.001). Echocardiography revealed increased interventricular septal thickness and left ventricular mass (p < 0.001), preserved fractional shortening, but elevated MPI and E/E′ ratio indicating diastolic dysfunction (both p < 0.001). IDMs also had higher rates of transient tachypnea (18% vs. 4%, p = 0.02), feeding difficulties (15% vs. 2%, p = 0.01), and longer hospital stay (5.2 ± 2.1 vs. 3.1 ± 1.0 days, p < 0.001). Maternal HbA1c correlated strongly with cTnI (r = 0.62) and BNP (r = 0.54). ROC analysis identified cTnI as the most accurate biomarker (AUC = 0.89; cut-off > 0.12 ng/mL; sensitivity 88%, specificity 84%). Elevated cTnI, BNP, and CK-MB in IDMs reflect cardiac stress linked to maternal hyperglycemia. Population-specific biomarker cut-offs, particularly cTnI > 0.12 ng/mL, may facilitate non-invasive screening for subclinical cardiac dysfunction, guiding selective echocardiography use. These thresholds require prospective multicenter validation.