Increased Plasma Pro-B-Type Natriuretic Peptide in Infants of Women with Type 1 Diabetes

Background: Up to 40% of newborn infants of women with type 1 diabetes have echocardiographic signs of cardiomyopathy. Increased plasma concentrations of B-type natriuretic peptide (BNP) and its precursor (proBNP) are markers of cardiac failure and hypoxia in adults. In this study, we investigated whether plasma concentrations of proBNP and/or BNP are increased in infants of women with type 1 diabetes. Methods: Plasma BNP and proBNP were measured with RIAs. The proBNP assay measures both intact proBNP and NH2-terminal fragments derived from this precursor, whereas the BNP assay measures only BNP-32 and not proBNP. Results: Infants of women with diabetes and hemoglobin A1c (Hb A1c) ≥6.2% before delivery had a higher median plasma proBNP concentration (31 pmol/L; interquartile range, 21–47 pmol/L; n = 16) than infants of healthy women [16 (9–32) pmol/L; n = 21; P = 0.01]. Infants of women with diabetes and Hb A1c <6.2% (n = 15) had intermediate values. The plasma BNP and proBNP concentrations were closely associated ( r 2 = 0.80; P <0.0001); within the group of infants of women with diabetes and Hb A1c ≥6.2%, both correlated with the degree of fetal stress during labor. Conclusions: Maternal diabetes and suboptimal metabolic control may affect the fetal heart and predominantly stimulate proBNP secretion in conjunction with perinatal stress.