Challenges in detecting the abuse of growth hormone in sport

Background: Growth hormone (GH) is reputed to be in widespread use in the sporting arena as a performance-enhancing agent and is on the list of banned substances published by the World Anti-Doping Agency. The detection of GH abuse poses many challenges. Unlike many substances of abuse, such as synthetic anabolic steroids, GH is a naturally occurring substance; therefore, demonstration of exogenous administration must rely on detecting concentrations in excess of an established reference interval. The purpose of this review is to discuss the methodologies being developed to detect GH abuse. Methods: We undertook a comprehensive search using multiple electronic databases and hand searches of reference lists of articles. The data for this review reflect our academic interests and experience through work on the GH-2000 and GH-2004 projects. Results: Two approaches have been taken to detect GH abuse. The first is based on assessment of the effect of exogenous GH on pituitary GH isoforms, and the second is based on measurement of markers of GH action. The advantages of each approach and the difficulties encountered with each technique, as well as future concepts in detection, are discussed. Conclusion: Although there are substantial challenges for the detection of GH, methodologies now exist to detect GH abuse with reasonable sensitivity and specificity. (C) 2005 American Association for Clinical Chemistry.