Growth Hormone in Sports: Detecting the Doped or Duped

Abstract

Background: Doping with growth hormone (GH) is banned; however, there is anecdotal evidence that it is widely abused. GH is reportedly often used in combination with anabolic steroids at high doses for several months. Development of a robust test for detecting GH has been challenging since recombinant human 22-kDa GH used in doping is indistinguishable analytically from endogenous GH and there are wide physiological fluctuations in circulating GH concentrations. Discussion: One approach to GH testing is based on measurement of different circulating GH isoforms using immunoassays that differentiate between 22-kDa and other GH isoforms. Administration of 22-kDa GH results in a change in its abundance relative to other endogenous pituitary GH isoforms. The differential isoform method is, however, limited by its short time window of detection. A second approach that extends the time window of detection is based on detection of increased levels of circulating GH-responsive proteins, such as the insulin-like growth factor (IGF) axis and collagen peptides. As age and gender are the major determinants of variability for IGF-I and the collagen markers, a test based on these markers must take these factors into account. Extensive data now validate the GH-responsive marker approach, and implementation is largely dependent on establishing an assured supply of standardized assays. Conclusions: Robust tests are available to detect GH and enforce the ban on its abuse in sports. Novel approaches that include gene expression and proteomic profiling must continue to be pursued to expand the repertoire of testing approaches available and to maintain deterrence of GH doping.

Gene doping: an overview and current implications for athletes

“…Despite a 1989 ban by the IOC on GH, there is evidence of GH being used as doping 19 51 67 74 75 77. A recent survey of 10th-grade boys in the USA showed that 5% had taken GH and 1.2% of college athletes admitted to have used GH in the last year 74 77.…”

“…A recent survey of 10th-grade boys in the USA showed that 5% had taken GH and 1.2% of college athletes admitted to have used GH in the last year 74 77. GH-gene therapy tests in mice, rabbits, sheep and pigs have been performed with varying results 70 78 79.…”

Annual banned‐substance review: analytical approaches in human sports drug testing

“…Despite the scientific controversies concerning the potential benefits of hGH with regard to athletic performance, anecdotal evidence is provided that hGH is still misused by numerous athletes . Much information has been generated to complement and improve the current methodology aiming especially for an extended detection window . In that context, the utility of the so‐called marker approach has been frequently discussed and might be considered fit‐for‐purpose in the very near future.…”

“…[64] Much information has been generated to complement and improve the current methodology aiming especially for an extended detection window. [65,66] In that context, the utility of the so-called marker approach has been frequently discussed and might be considered fit-for-purpose in the very near future. Since it relies on the statistically significant difference of biomarkers (predominantly the serum concentrations of insulin-like growth factor-1 (IGF-1) and N-terminal propeptide of type III procollagen (PIIINP) but also IGF-2 and the IGF binding proteins (IGFBPs) 2 and 3, influences other than hGH abuse on their variability have to be evaluated.…”