Editing Insulin-like growth factor (section)

== IGF-binding proteins ==

IGF-1 and IGF-2 are regulated by a family of proteins known as the [[Insulin-like growth factor-binding protein|IGF-binding proteins]].  These proteins help to modulate IGF action in complex ways that involve both inhibiting IGF action by preventing binding to the IGF-1 receptor as well as promoting IGF action possibly through aiding in delivery to the receptor and increasing IGF half-life.  Currently, there are seven characterized IGF Binding Proteins (IGFBP1 to IGFBP7).  There is currently significant data suggesting that IGFBPs play important roles in addition to their ability to regulate IGFs.
IGF-1 and IGFBP-3 are GH dependent, whereas IGFBP-1 is insulin regulated.
IGFBP-1 production from the liver is significantly elevated during insulinopenia while serum levels of bioactive IGF-1 is increased by insulin.<ref>{{Cite journal |last1=Brismar |first1=K. |last2=Fernqvist-Forbes |first2=E. |last3=Wahren |first3=J. |last4=Hall |first4=K. |title=Effect of insulin on the hepatic production of insulin-like growth factor-binding protein-1 (IGFBP-1), IGFBP-3, and IGF-I in insulin-dependent diabetes |url=https://pubmed.ncbi.nlm.nih.gov/7521354/ |journal=The Journal of Clinical Endocrinology and Metabolism |year=1994 |volume=79 |issue=3 |pages=872–878 |doi=10.1210/jcem.79.3.7521354 |issn=0021-972X |pmid=7521354}}</ref>