Metabolites of testosterone in Floyd Landis’ system after Stage 17, that is. I’ve been doing a lot of traveling over the past few weeks, leaving me away from the computer an awful lot. But it doesn’t mean I haven’t been thinking about and mulling over parts of the Landis case. (It’s a welcome diversion from other things I’ve been dealing with.)
After posting my last article (Flying Research), I started to look at and puzzle over Floyd Landis’ CIR/IRMS test results (see slides 20 and 21). And before I got a chance to write this article, reader TR commented:
“what this article shows is that the most likely explanation for Floyd Landis T/E ratios is that they were due to natural causes.”
how can it be due to natural causes if it is exogenous T?
Excellent question, TR. I’m glad you asked.
As a refresher (for those who don’t want to follow the link and look for themselves), here is a quick summary of Landis’ CIR results:
- 2 metabolites have reported values below the threshold for a positive result
- 1 has a reported value that is above the threshold, but still within the margin of error for the test, and
- 1 has a reported value that is well above the threshold for a positive test
LNDD, the UCI and WADA contend that this means Landis had exogenous (synthetic) testosterone in his system. The defense counters that it can only be considered a positive if all four metabolites show definite positive results. So who’s right? Let’s dig in.
Just to get things off on the right track, remember that the whole idea behind the CIR test is that synthetic hormones have a different percentage of carbon13 than hormones produced by the body. This comes from the knowledge that the body prefers to use carbon12 as the building block for the materials it makes. However, when a carbon12 atom isn’t available, the body will grudgingly use a carbon13 atom in its place. (OK, this isn’t quite accurate, the body doesn’t really have any feelings on the subject, so to say “grudgingly” is a bit of of an overstatement.)
Hormones synthesized in a lab use materials that come from different processes and sources than in the body, and these materials contain a different amount of carbon13. So, in theory, if you can determine the percentage difference between a reference hormone and another hormone, and if it exceeds a certain value, then the hormone you’re testing is deemed to be synthetic.
Where this theory breaks down is that a number of factors can affect how much carbon13 may be used by the body when it synthesizes hormones such as testosterone, including diet. But let’s assume that the theory holds true for the moment. And let’s assume that someone puts synthetic testosterone into an athlete’s system. And then let’s assume that for some reason, a urine test is done and it’s run through the CIR test to see whether there’s anything suspicious.
What results should we expect (besides the obvious, that the person has synthetic hormone present)? Now, before we answer this question, let’s consideer where those carbon13 atoms might be within the 19-carbon chain that is the backbone of a testosterone molecule. Any ideas? (Bueller? … Bueller? … Bueller?)
Well, how about this: anywhere within the chain. And when averaged out, in equal proportions at each position within the chain. So when synthetic testosterone is metabolized, what would the result be? Each metabolite would have carbon13 present. And in greater proportion than in the metabolites of “natural” testosterone.
So when you do a CIR test for synthetic testosterone, what should you expect? That all metabolites of testosterone will give positive readings for synthetic hormone.
Now, let’s circle back to the readings from Landis’ A sample. Remember, 2 tested within bounds, giving a negative result for synthetic testosterone. 1 was mildly elevated, let’s call this a “sort-of” positive. And 1 was definitely above the threshold.
With all tests, there’s a certain amount of uncertainty (eegads, I’m sounding like Donald Rumsfeld here!) associated with a given piece of data. The margin of error is the amount on either side of a piece of data (plus or minus), where the true data value could be. So let’s go back and look at the mildly elevated metabolite for a moment. It produced a value that was above the threshold, but still within the margin of error for the test.
What that means is that the lowest possible value for that particular reading is still in bounds of a normal result. Landis’ side looks at this as a negative result. I’d bet dollars to donuts that the other side calls it positive. And that’s why I call it a “sort-of” positive.
The last value we mentioned is clearly above the threshold, which is a “positive” result — but only for that metabolite.
So, to sum up the Landis CIR values: The Landis side argues that there’s one positive reading (which they contend is due to some sort of error), and the other side will surely argue that there’s two positive readings. But does that mean there’s a positive test?
No. As we discussed earlier, when doing CIR testing of synthetic testosterone, we should expect to see all four metabolites show positive results. Whether you call Floyd Landis’ results one positive or two, it’s still not a definitive finding of synthetic testosterone. In fact, given the expected result (all four metabolites return a positive result), this clearly falls into the category of a negative test.
Unless, of course, your name is Pat McQuaid or Dick Pound.
