Postnatal Changes in Ghrelin, Adiponectin, Insulin and Leptin Concentrations in Term Newborns

Birth denotes a sharp transition from constant placental nutrient delivery to independent regu-lation of energy intake and expenditure. Adipo-nectin, ghrelin, insulin and leptin are key hor-mones regulating appetite and energy homeosta-sis and could therefore be crucial components of postnatal adaptation. We studied the changes and relationships in these hormones and their correlation to clinical variables during adaptation to extrauterine life. Materials and Methods: Plasma venous adipo-nectin, ghrelin, insulin and leptin concentrations were measured at birth and controlled during early postnatal days (59.4+15.4 [SD] h, range 36-93 h) for 38 healthy newborn infants [(20 male, 18 female), gestational age 40.2+0.9 wk (mean+SD), range 37.9 to 42.1 wk] born from uncomplicated pregnancies. Results: Median adiponectin concentration at birth was at 25. 1 µg/mL (interquartile range 20. 0–29. 1 µg/mL) and during early postnatal days 17. 8 µg/mL (10.7-23.3; 95% CI of difference 26 to 46%). Median ghrelin concentration in cord plasma was 651 pg/mL (539-830) which during early postnatal days had decreased to 537 pg/mL (476-723; 95% CI 6 to 23%). At birth, median in-sulin concentration was 7.35 mU/L (6.53-9.43) and, during early postnatal days age, this was 4.35 mU/L (3.43-6.03; 95% CI 33 to 53%). At birth, median leptin concentration was 4.60 µg/L (3.51-5.84) and during early postnatal days was 0. 83 µg/L, (0. 65-1. 06; 95% CI 78 to 85%). At birth no correlation between hormone concentrations and gestational age or birth weight existed. During early postnatal days, adiponectin was positively (r=0. 49) correlated with ghrelin concentrations. Conclusion: In healthy term infants, the change from fetal to extrauterine life is accompanied by a decrease in circulating adiponectin, ghrelin, in-sulin and leptin suggesting distinct roles of these hormones in postnatal adaptation.