The Miami Marlins received shocking news as they came out of their four-game sweep of the Los Angeles Dodgers, as second baseman Dee Gordon tested positive for banned substances and was suspended 80 games per Major League Baseball's substance abuse policy. This came as a surprise to Marlins fans and to Gordon himself, who denied any willing ingestion of performance enhancers.
"Though I did not do so knowingly, I have been informed that test results showed I ingested something that contained prohibited substances," Gordon said Friday morning in a statement released by the MLB Players Association. "The hardest part about this is feeling that I have let down my teammates, the organization, and the fans. I have been careful to avoid products that could contain something banned by MLB and the 20-plus tests that I have taken and passed throughout my career prove this. I made a mistake and I accept the consequences."
The substances Gordon took, willingly or otherwise, were exogenous testosterone and clobestol. Testosterone, of course, is one of many androgenic hormones that your body naturally produces, typically from the gonadal organs. Since it is made in the body, one would suspect it would be difficult to test for a certain level of testosterone. Not only do some people naturally make more testosterone than others, but the levels produced by the body vary during different times of the day.
How can one test of exogenous, or out-of-body, production then? One way I presumed they would do it is to test for naturally-made byproducts in the production pathway of testosterone, and that appears to be the case. According to this 2006 article by Saudan et al in the Journal for Sports Medicine, doping measurements include the use of T/E ratio, which measures the ratio of testosterone excreted in the urine versus excretion of epitestosterone glucoronides.
Based on studies of athlete populations, the IOC adopted in 1983 a ratio of testosterone to epitestosterone glucuronides (T/E) with an authorised upper limit of 6.0 as a criterion for the administration of testosterone. Since epitestosterone is only a minor product of the metabolism of testosterone and does not increase after testosterone administration, the resulting effect is an increase in the T/E ratio.22
The epistestosterone would not be elevated if the steroids were taken exogenously. Thus, you can assess the difference between body production and outside use. Of course, these ratios can vary naturally depending on race, actual disease states, and other problems, as noted in the article.
In several studies, the distribution of results in Caucasian athlete populations shows generally a mean T/E ratio less than 2.0,20,23 whereas in Asian populations the mean T/E ratio is significantly lower. The IOC rules clearly indicate that a T/E ratio greater than 6.0 constituted an offence unless there was evidence that this ratio is due to a physiological or pathological condition—for example, low epitestosterone excretion, androgen producing tumour, and enzyme deficiencies.24 In addition, it has been observed that hepatic metabolism of steroid hormones may be altered by administration of substances as ethanol with the resulting effect of modifying significantly the T/E ratio.24
There are other testosterone tests that work in a similar fashion. I do not know which assay MLB uses for their own policy.
As for clostebol, it is a version of testosterone with a chlorine molecule attached to the ring. That provides it some stability in terms of metabolism; it is more difficult for basic body enzymes to convert it to dihydrotestosterone or estrogen, which would not provide the desired effect for the player. At the same time, the structure of the molecule is very similar to that of testosterone, which allows it to fit into some of the other body mechanisms that let it function like testosterone as a substrate.
Since clobestol does not naturally occur in the body, it can be tested as part of a general screen for products excreted in the urine. Of note, this is not a popular drug necessarily, though it is seen a lot apparently in Brazil. One off-hand study by a lab group authorized by the International Olympic Committee (IOC) for testing showed that you can see clobestol in a sample incidentally after sexual intercourse with a woman who used the drug via intravaginal topical cream use. However, the topical cream is only available in Brazil, so I think Gordon is unlikely to have received it in this fashion at least.
Whether Gordon received these unintentionally in other supplements or whether he willfully took these is irrelevant. There are decent testing mechanisms for both drugs, and both are anabolic steroids with potentially real and desired effects for athletes. Unfortunately, Gordon will have to sit for 80 games as a result.