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 NH(2)-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 A(1c) (Hb A(1c)) > or =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 A(1c) <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 A(1c) > or =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.