Ghrelin levels from fetal life through early adulthood: relationship with endocrine and metabolic and anthropometric measures

OBJECTIVE: To establish mean plasma ghrelin levels during fetal life and childhood.Study design Cord blood was obtained at birth from premature (n=29) and full-term newborns (n=124). Fasting blood samples were taken from 224 normal subjects divided according to Tanner stage and sex. Ponderal index or body mass index was determined. Ghrelin; insulin-like growth factor (IGF)-I; IGF-II; IGF binding proteins 1, 2, and 3; insulin; glucose; and leptin levels were measured. RESULTS: Ghrelin levels did not differ between preterm and full-term newborns. Ghrelin increased significantly after birth, peaking during the first 2 years of life, then decreasing until the end of puberty. Ghrelin levels correlated negatively with anthropometric variables in full-term newborns and postnatally, but not in preterm newborns. A positive correlation between ghrelin and IGF binding protein 1 was found. CONCLUSIONS: Ghrelin changes significantly throughout development, correlating with anthropometric and metabolic parameters during extrauterine life. The highest levels of ghrelin are found during early postnatal life, when growth hormone begins to exert its effects on growth and important changes in food intake occur, suggesting that this hormone may participate in these processes.