title: IGF-I abuse in sport.
abstract: It is widely believed that growth hormone (GH) is abused by athletes for its anabolic and lipolytic effects. Many of the physiological effects of GH are mediated by the production of insulin-like growth factor-I (IGF-I). Both GH and IGF-I appear on the World Anti-Doping Agency list of prohibited substances. Little is known, however, about the prevalence of abuse with exogenous IGF-I. IGF-I has effects on carbohydrate, lipid and protein metabolism and some of these actions could prove beneficial to competitive athletes. No studies have demonstrated a positive effect of IGF-I on physical performance in healthy individuals but this has not yet been studied in appropriately designed trials. Two pharmaceutical preparations of IGF-I have recently become available for the treatment of growth disorders in children. This availability is likely to increase the prevalence of IGF-I abuse. Combining IGF-I with its binding protein IGFBP-3 in one preparation has the potential to reduce the side-effect profile but the adverse effects of long term IGF-I abuse are currently unknown. Detection of abuse with IGF-I is a major challenge for anti-doping authorities. It is extremely difficult to distinguish the exogenous recombinant form of the hormone from endogenously-produced IGF-I. One approach currently being investigated is based on measuring markers of GH and IGF-I action. This has already proved successful in the fight against GH abuse and, it is hoped, will subsequently lead to a similar test for detection of IGF-I abuse.
authors.affiliation: Endocrinology and Metabolism Sub-Division, Developmental Origins of Adult Health and Disease Division, School of Medicine, University of Southampton, Southampton, SO16 6YD, UK. n.guha@soton.ac.uk
authors.forename: Nishan
authors.initials: N
authors.lastname: Guha
authors.forename: Alexander
authors.initials: A
authors.lastname: Dashwood
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Thomas
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Skingle
authors.forename: Peter H
authors.initials: PH
authors.lastname: Sönksen
authors.forename: Richard I G
authors.initials: RI
authors.lastname: Holt
mesh_terms: D000818:Animals; D056352:Athletes; D054874:Athletic Performance; D004300:Doping in Sports; D019382:Human Growth Hormone / Q000494:pharmacology; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000008:administration & dosage; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D013177:Sports; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000453:epidemiology
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I