Plasma brain natriuretic peptide concentrations in healthy children from birth to adolescence: marked and rapid increase after birth.

The aim of the present study is to establish the normal range and to determine the developmental changes of plasma brain natriuretic peptide (BNP) concentrations in children. We measured plasma BNP concentrations as well as atrial natriuretic peptide (ANP) concentrations in 58 healthy children from birth to adolescence and in the umbilical vein of 20 healthy neonates using highly sensitive immunoradiometric assays. The plasma BNP concentration was the highest at 0 days of age and descended through maturation to be almost constant and to be at the adult level at 3 months of age. The plasma BNP concentration at 0 days of age (56.7 +/- 49.6 fmol/ml; mean +/- SD) was 25 to 30 times higher than the adult level and 21 times higher than that in the umbilical vein (2.7 +/- 1.4 fmol/ml). The plasma ANP concentration at 0 days of age was not significantly different from that in the umbilical vein. The ratio of BNP to ANP was also the highest at 0 days of age (1.39 +/- 0.72) and decreased through maturation to be at the adult level at 3 months of age. Thus, the plasma BNP concentration in healthy subjects showed a marked, rapid and preferential increase immediately after birth, suggesting that BNP has a physiological role distinct from that of ANP in the perinatal circulatory changes from fetus to neonate.