IGF-I abuse in sport: current knowledge and future prospects for detection.
As the tests for detecting growth hormone (GH) abuse develop further, it is likely that athletes will turn to doping with insulin-like growth factor-I (IGF-I). IGF-I mediates many of the anabolic actions of growth hormone. It stimulates muscle protein synthesis, promotes glycogen storage and enhances lipolysis, all of which make IGF-I attractive as a potential performance-enhancing agent. Pharmaceutical companies have developed commercial preparations of recombinant human IGF-I (rhIGF-I) for use in disorders of growth. The increased availability of rhIGF-I increases the opportunity for athletes to acquire supplies of the drug on the black market. The long-term effects of IGF-I administration are currently unknown but it is likely that these will be similar to the adverse effects of chronic GH abuse. The detection of IGF-I abuse is a challenge for anti-doping organisations. Research has commenced into the development of a test for IGF-I abuse based on the measurement of markers of GH action. Simultaneously, the effects of rhIGF-I on physical fitness, body composition and substrate utilisation in healthy volunteers are being investigated.
Guha
Nishan
N
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
Sönksen
Peter H
PH
Holt
Richard I G
RI
D056352:Athletes; D001823:Body Composition; D002241:Carbohydrates / Q000737:chemistry; D004300:Doping in Sports; D006003:Glycogen / Q000378:metabolism; D019382:Human Growth Hormone / Q000032:analysis / Q000627:therapeutic use; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000172:deficiency* / Q000627:therapeutic use*; D011994:Recombinant Proteins / Q000627:therapeutic use*; D013177:Sports; D015813:Substance Abuse Detection / Q000379:methods* / Q000639:trends*
D002241:Carbohydrates; D011994:Recombinant Proteins; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D006003:Glycogen