Insulin-like growth factor 1 (IGF-1), also called somatomedin C, is a hormone similar in molecular structure to insulin which plays an important role in childhood growth, and has anabolic effects in adults.[5] In the 1950s IGF-1 was called "sulfation factor" because it stimulated sulfation of cartilage in vitro,[6] and in the 1970s due to its effects it was termed "nonsuppressible insulin-like activity" (NSILA).[7]
IGF-1 is produced primarily by the liver. Production is stimulated by growth hormone (GH). Most of IGF-1 is bound to one of 6 binding proteins (IGF-BP). IGFBP-1 is regulated by insulin. IGF-1 is produced throughout life; the highest rates of IGF-1 production occur during the pubertal growth spurt.[12] The lowest levels occur in infancy and old age.[13][14]
Low IGF-1 levels are associated with cardiovascular disease, while high IGF-1 levels are associated with cancer. Mid-range IGF-1 levels are associated with the lowest mortality.
A synthetic analog of IGF-1, mecasermin, is used for the treatment of growth failure in children with severe IGF-1 deficiency.[15]Cyclic glycine-proline (cGP) is a metabolite of hormone insulin-like growth factor-1 (IGF-1). It has a cyclic structure, lipophilic nature, and is enzymatically stable which makes it a more favourable candidate for manipulating the binding-release process between IGF-1 and its binding protein, thereby normalising IGF-1 function.[16]
^Salmon WD, Daughaday WH (June 1957). "A hormonally controlled serum factor which stimulates sulfate incorporation by cartilage in vitro". The Journal of Laboratory and Clinical Medicine. 49 (6): 825–836. PMID13429201.
^Meuli C, Zapf J, Froesch ER (April 1978). "NSILA-carrier protein abolishes the action of nonsuppressible insulin-like activity (NSILA-S) on perfused rat heart". Diabetologia. 14 (4): 255–259. doi:10.1007/BF01219425. PMID640301.
^Höppener JW, de Pagter-Holthuizen P, Geurts van Kessel AH, Jansen M, Kittur SD, Antonarakis SE, et al. (1985). "The human gene encoding insulin-like growth factor I is located on chromosome 12". Human Genetics. 69 (2): 157–160. doi:10.1007/BF00293288. PMID2982726. S2CID5825276.
^Landin-Wilhelmsen K, Wilhelmsen L, Lappas G, Rosén T, Lindstedt G, Lundberg PA, et al. (September 1994). "Serum insulin-like growth factor I in a random population sample of men and women: relation to age, sex, smoking habits, coffee consumption and physical activity, blood pressure and concentrations of plasma lipids, fibrinogen, parathyroid hormone and osteocalcin". Clinical Endocrinology. 41 (3): 351–357. doi:10.1111/j.1365-2265.1994.tb02556.x. PMID7955442. S2CID24346368.