Insulin-like growth factor binding protein 3 (IGFBP-3) functions as a binding protein for IGF-1. IGF-1, also called somatomedin C, is primarily produced by the liver as an endocrine hormone and plays an influential role in virtually every system from muscle, bone, and connective tissue growth and repair, to the selective regulation of various aspects of metablism, as well as helping maintain normal brain function and cardiac health.
IGFBP-3 is related to the production and secretion of growth hormone (GH). GH has a very short half-life which makes it unreliable to test in order to get an accurate representation of its own, actual level. However, IGFBP-3 appears constant over a 24-hour period, making it a useful bio-marker to help assess blood levels of GH.
Fasting is not required for this test. Take all medications as prescribed.