Testosterone test measures ratio

UCI lowered acceptable level last year

July 28, 2006|By DAVID KOHN | DAVID KOHN,SUN REPORTER

The test that might have snared Tour de France champion Floyd Landis was devised more than two decades ago and is widely used by athletic regulatory agencies. It measures the ratio of the steroid hormone testosterone, which helps build muscle, to a related substance, epitestosterone, a byproduct of testosterone that has no known physical function.

In most people, the ratio of the chemicals is about 1-to-1. But because a small percentage of people have more testosterone than epitestosterone, most athletic oversight agencies allow for a higher ratio. For many years, the maximum was 6-to-1.

Last year several ruling bodies, including the International Olympic Committee, the NFL and UCI, the international governing body of cycling that oversees the Tour de France, lowered the permissible ratio to 4-to-1. The ratio in Landis' sample was not disclosed.

Dr. Linn Goldberg, a doping expert at Oregon Health & Science University, said that athletes can elude the test. Some, he said, inject synthetic epitestosterone in addition to testosterone in an attempt to keep the ratio constant.

"You can cheat the test by taking epitestosterone," he said. "The ratio can be cheated."

After a positive T/E ratio test, doping agencies typically require another test. Invented in the mid-1990s, the Carbon Isotope Ratio test discerns differences between carbon atoms in synthetically manufactured steroid hormones and naturally produced human testosterone.

This test costs much more than the T/E ratio test - several hundred dollars versus less than $100 for the latter - and is not usually done unless there is already evidence of cheating. Both CIR and T/E ratio are urine-based tests.

According to published reports, the French lab administering the tests has evaluated only one of Landis' two specimens. Until an analysis of the second specimen is completed, the T/E result will remain in doubt. Experts say that the second urine sample often undergoes both the T/E and CIR tests.

Doping experts disagreed on whether an athlete might gain an advantage from taking testosterone during a long-distance event such as the Tour de France. Some argued that testosterone is only useful for building muscle before an event.

"It doesn't usually work overnight," said New York University's Dr. Gary Wadler, one of the nation's foremost experts on steroid abuse.

"It is usually used on a six- or 12-week cycle. It is a long-term drug," Wadler said. He said that from this perspective, Landis' positive test "makes no sense."

Goldberg, however, said that testosterone can help muscles recover from great effort. In a grueling sport such as cycling, recuperation is crucial. "The way you can recover faster is by taking testosterone," he said.

david.kohn@baltsun.com

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