The Floyd Landis announcement today, and the sports radio coverage of it sent me to the internet. One of the radio reports says the discrepancy was in the ratio of epitestosterone (E) to testosterone (T) in the urine, about which I was ignorant.
So, off to MD Consult, where Primary Care: Clinics in Office Practice, Volume 32 • Number 1 • March 2005 says the difficulty catching athletes abusing T for performance enhancement was cracked by:
…measuring the ratio of testosterone to epitestosterone, with a result of greater than 6:1 considered suggestive of exogenous testosterone administration .
 was a reference to Issues in detecting abuse of xenobiotic anabolic steroids and testosterone by analysis of athletes’ urine. Catlin DH – Clin Chem – 01-JUL-1997; 43(7): 1280-8 which says:
…The process of determining if an athlete has used testosterone (T) begins with finding a T to epitestosterone (E) ratio > 6 and continues with a review of the T/E-time profile. For the user who discontinues taking T, the T/E reverts to baseline (typically approximately 1.0). For the extremely rare athlete with a naturally increased T/E ratio, the T/E remains chronically increased. Short-acting formulations of T transiently increase T/E, and E administration lowers it. ….
So, what’s to be done? It’s not only a retesting of the ‘backup sample’ but a comparison of ratios from previous samples. Landis has been racing long enough there’s probably 200 gallons of his pee in little bottles available for comparison.
I should note this is from a 15 minute session looking at the first literature hits; also, I don’t have anything to do with drug testing in sports. I’m waiting with you to see what happens.