Serum levels of insulin-like growth factors (IGF-1 and IGF-2), insulin, insulin-like growth factor binding protein-1 (IGFBP-1), growth hormone (GH) and growth homone-binding protein (GH-BP) activity were assessed in a group of healthy newborns and reevaluated at one and three months of life in six of them. A significant decrease in IGFBP-1 plasma levels was observed at one month (p< 0.002) and three months (p< 0.02) of life compared to cord blood values. IGF-1 plasma levels did not change during the first three months of life. In contrast, IGF-2 plasma levels increased significantly at three months of life compared to cord blood values (p< 0.002). GH plasma levels showed a significant decrease at three months of life (p<0.03). GH-BP activity was low at birth and did not change significantly during the first three months of life. The low GH-BP activity may reflect the GH receptor status, indicating that GH receptors are poorly expressed in early infancy. The high IGFBP-1 plasma levels in newborns could be important in protecting them from hypoglycemia.
Plasma levels of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 in women with cervical neoplasia
