Thursday, July 27, 2006

Ethanol and T/E Tests

A comment referred to the amount of ethanol needed to mask. In looking this up I was astounded to find that ethanol actually elevates T/E ratios dramatically. Here's an article I found online and it supports what I've discovered today, that the T/E test is bad science:

The Effect of Alcohol Consumption on the Urinary Testosterone / Epitestosterone Ratio

By Dr Simon Davis B.Sc., Ph.D.


Intoxicating beverages contain a number of different forms of alcohol, the major constituent of which is ethanol. When a beverage is consumed the ethanol content passes through the stomach wall and digestive tract into the blood stream. Once the ethanol enters circulation it begins to alter the bodies’ biochemistry. One such reaction is to differentially increase the rates of testosterone (T) and epitestosterone (E) metabolism. The overall effect of this reaction is to increase the ratio of T to E excreted in the urine.

It has been reported that ethanol consumption can increase urinary T/E ratios by 30% - 277% in healthy individuals. Observed changes in plasma T/E ratios can occur with the consumption of less than 2 pints of lager. The ingestion of ethanol by an individual will increase the T/E ratio observed in a urine sample.

It follows that if the effect of ethanol on T/E ratios is calculated relative to urinary E concentrations, it can be seen that increases in the ratio are exponential as E concentrations decrease. Individuals with naturally low E concentrations could, therefore, experience increases in T/E ratios of ? 940% greater than increases experienced in an individual with normal E concentrations. Calculations estimate that in individuals with low urinary E concentration, ratios of 17 to 1 or higher could have resulted from ethanol consumption without any administration of exogenous T.

The current T/E ratio test as performed by Kings College Laboratory and approved by the UK Sports, the IWF and IOC cannot discriminate between a 13 to 1 T/E ratio resulting from ethanol ingestion or a 13 to 1 ratio resulting from endogenous T administration.


Blogger Jarrett said...

Wow - this is utterly fascinating. Thank you for posting it (and the blog as a whole, too).

I've been skeptical of Landis's innocence, but this seems significant enough to render my skepticism irrational.

I'm curious how many clean atheletes will volunteer to be tested enough to establish their normal T/E levels, in order to be tested again after a one-night bender. And how soon those results will make it into a peer reviewed publication. And how soon after that it might upset this form of testing forever.

If this study is correct, I hope this happens soon - and that no professional atheletes go out drinking during races in the meanwhile.


1:56 AM  
Blogger Free Floyd said...

I think you're right to be skeptical of Landis' innocence jarrett just so long as you remain skeptical of his guilt too. what I really hope is that we regular people on the street--if we truly want fairness in competition--demand fairness in the testing mechanisms as well. but when shoddy tests are bundled up with media circuses.
WRT more T/E studies, I think it's a bad idea. If these professional organizations want to test, then they need to invest. Invest in more definitive tests. Like IRMS. Don't half-assed test these guys. Of if they do choose to do these half-assed tests, let the tests like the T/E serve a silent prescreen method, not something that leads automatically to the humiliation of an individual. They should never release the results until a T/E is backed up with an IRMS.

9:03 AM  
Blogger mobytom said...

That article is nothing more than a treatise written for the sole purpose of supporting the defense of another athlete that the writer of the article does not name. From that point of view alone it is worthless. From the point of view of prevailing science it does not stand up either. Do more research :)

3:49 AM  
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2:45 AM  

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