Sexual Dimorphism in the Growth Hormone and Insulin-Like Growth Factor Axis at Birth (original) (raw)

2003, The Journal of Clinical Endocrinology & Metabolism

In rodents and humans there is a sexually dimorphic pattern of GH secretion that influences the serum concentration of IGF-I. Pattern differences can be identified in children, but it is not known how early this difference is established. We studied the plasma concentrations of IGF-I, IGF-II, IGF-binding protein-3 (BP-3), and GH in cord blood taken from the offspring of 1650 singleton Caucasian pregnancies born at term and related these values to birth weight, length, and head circumference. Pregnancies complicated by preterm delivery, antepartum hemorrhage, pregnancy-induced hypertension, preeclampsia, or gestational diabetes and where cigarette smoking continued were excluded, resulting in a cohort of 987. Cord plasma concentrations of IGF-I, IGF-II, and IGFBP-3 were influenced by factors influencing birth size: gestational age at delivery, mode of delivery, maternal height, and parity of the mother. Plasma GH concentrations were inversely related to the plasma concentrations of IGF-I and IGFBP-3; 10.2% of the variability in cord plasma IGF-I concentration and 2.7% for IGFBP-3 was explained by sex of the offspring and parity. None of the factors, apart from maternal height, influenced cord serum IGF-II concentrations (adjusted r 2 ‫؍‬ 1%).