The good, the bad and the ugly
A medical perspective on clean athletes, dopers and abuse of the system
When I worked with the international medical research team investigating a method for detecting athletes doping with growth hormone (GH), I was struck by the co-operation of the medical teams and the athletes supporting this research in various countries. This project was supported by the International Olympic Committee and the drug companies manufacturing growth hormone who did not want to see this product mis-used.
Why would athletes seek to dope with GH? GH alters body composition by increasing lean mass and decreasing fat mass, a potential advantage for power sports. In addition to this anabolic effect, GH is potentially advantageous to physiology and metabolism in endurance sport by increasing use of lipid over glycogen as a substrate. However there are serious side effects of elevated GH levels as seen in patients suffering with acromegaly: including increased risk of diabetes mellitus, hypertension and cancer.
One of the challenges we encountered in developing a dope test for GH was that endogenously secreted growth hormone was virtually identical to the manufactured product. In addition, this peptide hormone is released episodically in a pulsatile manner and has a short plasma half life. So early on it was realised that direct measurement of growth hormone was not a reliable option, rather quantification of indirect plasma markers would be required. In turn that meant investigating the pharmacokinetic properties of these markers in exercising people.
So far so good. However what are the “normal” ranges for growth hormone and these secondary markers in elite athletes? The ranges used in the usual clinical hospital setting may not be accurate as exercise is a major stimulus for growth hormone release. Part of the reason elite athletes are better than amateur athletes is that they may have slightly different physiology and/or genetically determined physiology that responds more rapidly to training than the rest of us. So the first step was establishing what normal ranges are for growth hormone and its associated markers in elite athletes. Cue trips to Manchester velodrome with portable centrifuges, taking blood from Olympic medal winning rowers at the British Olympic Park and numerous evenings performing VO2 max tests on athletes.
Throughout this research I was struck by the desire of the elite athletes to participate in a study that would identify cheats, allowing them, as clean athletes, to compete on a level playing field. This gave those of us in medical research team extra incentive to come up with the most reliable and robust test possible. Nevertheless, we were aware that an arms race was taking place, with the dopers trying equally hard to cheat our test. Ultimately, however scientifically robust a test may be, it will not succeed if there is manipulation of the samples provided. This is what makes the alleged systemic abuse of the process so ugly.
From population based norms to personalised medicine: Health, Fitness, Sports Performance Dr N.Keay, British Journal of Sport Medicine 22/2/17
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