So yesterday I commented on the news of rugby player Terry Newton receiving a two-year ban because he tested positive for growth hormone. Now I’ve had twenty-four hours to look the story up I figure its time to discuss the actual test itself.
Growth hormone has long thought to be untraceable due to its incredibly short half-life (approx 25 minutes). This sort of ignorance is going to get a lot of professional athletes into trouble, and I’ll admit I had no idea this was possible until yesterday. Then again, I don’t follow drug testing on a daily basis, nor am I a professional drug-using athlete who needs to be on top of this kind of information. All the news articles discussing the rugby star’s ban mentioned blood analysis, but gave no details of the testing procedure so I had to delve a little bit deeper. Believe it or not, there are actually two distinct methods for testing, developed by two independent teams. The first test is called the “isoform approach”, which in the words of the researchers, “directly analyzes the spectrum of molecular isoforms in circulation: the pituitary gland secretes a spectrum of homo- and heterodimers and – multimers of a variable spectrum of hGH isoforms, whereas rhGH consists of the monomeric 22,000 Da isoform only.” In Layman’s, this means that synthetic hGH can differ slightly from the hGH made by your pituitary. An isoform just means a different type of the same protein, kind of like how you can have a red chair and a blue chair, but they are both chairs. This test was developed in Berlin, Germany led by Professor Christian Strasburger and appears to be the test used to catch out Terry Newton. Unfortunately this test only works for a few days after hGH use.
The second test is known as the “marker approach” which was developed at Southampton University in England led by Professor Peter Sonksen. It involves looking at GH-dependant biomarkers IGF-I and type 3 procollagen (P-III-P) which appear to vary differently from endogenous and exogenous GH. This test claims to be able to test up to 14 days after use, which is quite incredible for a drug once thought to be impossible to detect. The World Anti-Doping-Agency (WADA) is looking to combine these testing methods into one robust testing procedure.
Yesterday I questioned when the MLB and NFL would consider implementing this testing. As it turns out, the minor leagues are lining up to start testing and there are calls for the NFL to include it also. Links to articles on both stories can be found beneath the sources at the bottom of the page.
Bidlingmaier M, Strasburger CJ. Growth hormone. Handb Exp Pharmacol. 2010;(195):187-200.
Erotokritou-Mulligan I, Eryl Bassett E, Cowan D, Bartlett C, Milward P, Sartorio A, Sönksen PH, Holt RI. The use of growth hormone (GH)-dependent markers in the detection of GH abuse in sport: Physiological intra-individual variation of IGF-I, type 3 pro-collagen (P-III-P) and the GH-2000 detection score. Clin Endocrinol (Oxf). 2009 Jul 24.