What is the Origin of IGF-1 Serum Levels?

The term is derived from the molecule's function—it is insulin-like due to its structural similarity to insulin and its ability to modulate glucose uptake, and it is a growth factor that mediates the effects of GH. Measurement of its concentration in the serum is the standard clinical method for evaluating the long-term biological activity of GH.

What is the Mechanism of IGF-1 Serum Levels?

IGF-1 acts as the primary effector of Growth Hormone's anabolic actions. When GH binds to its receptor in the liver, it triggers the synthesis and secretion of IGF-1 into the circulation. IGF-1 then travels to target tissues, where it binds to the IGF-1 receptor, activating intracellular signaling pathways, most notably the PI3K/Akt pathway, which promotes cell proliferation, inhibits apoptosis, and enhances protein synthesis. The circulating serum level thus directly reflects the cumulative anabolic drive of the somatotropic system.

IGF-1 Serum Levels

Meaning

IGF-1 Serum Levels represent the measurable concentration of Insulin-like Growth Factor-1 circulating in the bloodstream, a critical anabolic hormone primarily synthesized by the liver in response to Growth Hormone (GH) stimulation. This level serves as the most stable and clinically useful biomarker for assessing overall somatotropic axis function and GH sufficiency. Optimal levels are essential for cellular growth, tissue repair, bone remodeling, and maintaining lean body mass throughout the lifespan.