Insulin, growth hormone and sport.
This review examines some interesting 'new' histories of insulin and reviews our current understanding of its physiological actions and synergy with GH in the regulation of metabolism and body composition. It reviews the history of GH abuse that antedates by many years the awareness of endocrinologists to its potent anabolic actions. Promising methods for detection of GH abuse have been developed but have yet to be sufficiently well validated to be ready for introduction into competitive sport. So far, there are two promising avenues for detecting GH abuse. The first uses immunoassays that can distinguish the isomers of pituitary-derived GH from the monomer of recombinant human GH. The second works through demonstrating circulating concentrations of one or more GH-sensitive substances that exceed the extremes of normal physiological variability. Both methods require blood rather than urine samples. The first method has a window of opportunity lasting about 24 h after an injection and is most suitable for 'out of competition' testing. The second method has reasonable sensitivity for as long as 2 weeks after the last injection of GH and is uninfluenced by extreme exercise and suitable for post-competition samples. This method has a greater sensitivity in men than in women. The specificity of both methods seems acceptably high but lawyers need to decide what level of scientific probability is needed to obtain a conviction. Both methods need further validation before implementation. Research work carried out as part of the fight against doping in sport has opened up a new and exciting area of endocrinology.
Sonksen
P H
PH
Guy's, King's and St Thomas' School of Medicine, St Thomas' Hospital, London SE1 7EH, UK. peter.sonksen@kcl.ac.uk
D000375:Aging / Q000097:blood; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001786:Blood Glucose / Q000378:metabolism; D002352:Carrier Proteins / Q000097:blood; D004300:Doping in Sports / Q000379:methods / Q000517:prevention & control* / Q000523:psychology; D005260:Female; D006023:Glycoproteins / Q000097:blood; D013006:Growth Hormone / Q000008:administration & dosage / Q000097:blood* / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000502:physiology*; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000502:physiology; D007391:International Cooperation; D008297:Male; D008970:Molecular Weight; D015675:Osteocalcin / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011347:Procollagen / Q000097:blood; D020033:Protein Isoforms / Q000097:blood; D012680:Sensitivity and Specificity; D012737:Sex Factors; D015813:Substance Abuse Detection / Q000379:methods*
D015415:Biomarkers; D001786:Blood Glucose; D002352:Carrier Proteins; D006023:Glycoproteins; D007328:Insulin; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D010446:Peptide Fragments; D011347:Procollagen; D020033:Protein Isoforms; C075944:insulin-like growth factor binding protein, acid labile subunit; C041876:procollagen Type III-N-terminal peptide; C042813:procollagen type I carboxy terminal peptide; D015675:Osteocalcin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone