Leptin As A Marker Of Sexual Dimorphism In Newborn Infants

Abstract

Objective: To determine cord blood leptin levels in newborns appropriate for gestational age, according to gender, birth weight, birth height and ponderal index. Methods: A cross-sectional study was carried out with 132 term newborns appropriate for gestational age (68 females, 64 males), gestational age between 35-42 weeks. Data were collected through interviews with the mothers at the maternity, anthropometrycal study of the newborns, and cord blood estradiol, testosterone and leptin assays obtained immediately after birth. Results: The levels of leptin were significantly higher in females than in males (8.34±0.65 ng/ml versus 6.06±0.71 ng/ml; p = 0.000). The concentrations of estradiol and testosterone did not differ between males and females. Leptin levels were positively correlated with gestational age (r = 0.394, p < 0.01), birth weight (r = 0.466, p < 0.01), birth length (r = 0.335, p < 0.01) and ponderal index (r = 0.326, p < 0.01). Conclusions: Leptin concentration in the umbilical cord is positively correlated with gestational age, birth weight, birth height, and ponderal index, suggesting its participation in the neonatal growth process. In addition, a gender difference with higher levels of leptin in females neonates was observed, suggesting that the sexual dimorphism in relation to body composition already exists in newborns. Copyright © 2004 by Sociedade Brasileira de Pediatria.804305308Zhang, Y., Proenca, R., Maffei, M., Barone, M., Leopold, L., Friedman, J., Positional cloning of the mouse obese gene and its human homologue (1994) Nature, 372, pp. 425-432Seeley, R.J., Schwartz, M.W., Neuroendocrine regulation of food intake (1999) Acta Paediatr Suppl, 88 (428), pp. 58-61Cunningham, M.J., Clifton, D.K., Steiner, R.A., Leptini's actions on the reproductive axis: Perspectives and mechanisms (1999) Biol Reprod, 60, pp. 216-222Koistinen, H.A., Koivisto, V.A., Kontula, K., Andersson, S., Teramo, K.A., Leptin concentration in cord blood correlates with intrauterine growth (1997) J Clin Endocrinol Metab, 82, pp. 3328-3330Schubring, C., Kiess, W., Englaro, P., Rascher, W., Dotsch, J., Blum, W., Levels of leptin in maternal serum, amniotic fluid, and arterial and venous cord blood: Relation to neonatal and placental weight (1997) J Clin Endocrinol Metab, 82, pp. 1480-1483Tarquini, B., Tarquini, R., Perfetto, F., Cornelissen, G., Halberg, F., Genetic and environmental influences on human cord blood leptin concentration (1999) Pediatrics, 103, pp. 998-1006Alexander, G.R., Himes, J.H., Kaufman, R.B., Mor, J., Kogan, M., A United States National Reference for fetal growth (1996) Obstet Gynecol, 87, pp. 163-168Monte, O., Longui, C.A., Calliari, L.E.P., (1998) Endocrinologia Pediátrica, , São Paulo: Editora AtheneuVan Den Brandle, J.L., Somatomedins on the move (1990) Horm Res, 33, pp. 58-68Gómez, L., Carrascosa, A., Yeste, D., Potau, N., Riqué, S., Almar, J., Leptin values in placental cord blood of human newborns with normal intrauterine growth after 30-42 weeks of gestation (1999) Horm Res, 51, pp. 10-14Vatten, L.J., Nilsen, S.T., Odegård, R.A., Romundstad, P.R., Austgulen, R., Insulin-like growth factor I and leptin in umbilical cord plasma and infant birth size at term (2002) Pediatrics, 109, pp. 1131-1135Hassink, S.G., Lancey, E., Sheslow, D.V., Considine, R.V., Dostal, K., Smith-Kirwin, S.M., Placental leptin: Important new growth factor in intrauterine and neonatal development? (1997) Pediatrics, 100, pp. E1Tamura, T., Goldenberg, R.L., Johnston, K.E., Cliver, S.P., Serum leptin concentrations during pregnancy and their relationship to fetal growth (1998) Obstet Gynecol, 91, pp. 389-395Schubring, C., Englaro, P., Siebler, T., Blum, W.F., Demirakca, T., Kiess, W., Longitudinal analysis of maternal serum leptin levels during pregnancy, at birth and up to six weeks after birth: Relation to body mass index, skinfolds, sex steroids and umbilical blood leptin levels (1998) Horm Res, 50, pp. 276-283Matsuda, J., Yokota, I., Iiida, M., Murakami, T., Naito, E., Ito, M., Serum leptin concentration in cord blood: Relationship to birth weight and gender (1997) J Clin Endocrinol Metab, 82, pp. 1642-1644Helland, I.B., Reseland, J.E., Saugstad, O.D., Drevon, C.A., Leptin levels in pregnant women and newborn infants: Gender differences and reduction during the neonatal period (1998) Pediatrics, 101, pp. E12Geary, M., Pringle, P.J., Persaud, M., Wilshin, J., Hindmarsh, P.C., Rodeck, C.H., Leptin concentrations in maternal serum and cord blood: Relationship to maternal anthropometry and fetal growth (1999) Br J Obstet Gynaecol, 106, pp. 1054-1060Schulz, S., Häckel, C., Weise, W., Hormonal regulation of neonatal weight: Placental leptin and leptin receptors (2000) BJOG, 107, pp. 1486-1491Lepercq, J., Lahlou, N., Timsit, J., Girard, J., Mouzon, S.H., Macrosomia revisited: Ponderal index and leptin delineate subtypes of fetal overgrowth (1999) Am J Obstet Gynecol, 181, pp. 621-625Papadopoulou, F.G., Mamopoulos, A.M., Triantos, A., Constantinidis, T.C., Papadimas, J., Assimakopoulos, E.A., Leptin levels in maternal and cord serum: Relationship with fetal development and placental weight (2000) J Matern Fetal Med, 9, pp. 298-302Ogueh, O., Sooranna, S., Nicolaides, K.H., Johnson, M.R., The relationship between leptin concentration and bone metabolism in the human fetus (2000) J Clin Endocrinol Metab, 85, pp. 1997-1999Christou, H., Connors, J.M., Ziotopoulou, M., Hatzidakis, V., Papathanassoglou, E., Ringer, S.A., Cord blood leptin and insulin-like growth factor levels are independent predictors of fetal growth (2001) J Clin Endocrinol Metab, 86, pp. 935-938Su, P.H., Wang, S.L., Chen, J.Y., Lai, C.P., Jian, S.H., Serum leptin levels in preterm, healthy and sick-term newborns (2002) Acta Paediatr, 43, pp. 249-254. , TaiwanYang, M.J., Liu, R.S., Hung, J.H., Leptin concentrations in the umbilical vein and artery. Relationship to maternal and neonatal anthropometry (2002) J Reprod Med, 47, pp. 645-650Ong, K.K., Ahmed, M.L., Sherriff, A., Woods, K.A., Watts, A., Golding, J., Cord blood leptin is associated with size at birth and predicts infancy weight gain in humans (1999) J Clin Endocrinol Metab, 84, pp. 1145-1148Copper, R.L., Goldenberg, R.L., Cliver, S.P., Dubard, M.B., Hoffman, H.J., Davis, R.O., Anthropometric assessment of body size differences of full-term male and female infants (1993) Obstet Gynecol, 81, pp. 161-16