INDEPTH: EPO
The dangers of EPO
John Bowman, CBC News Online | Updated October 24, 2003
EPO has fast become a popular drug among high-performance athletes. Effective at boosting performance and virtually undetectable, EPO can also be deadly.
EPO, or erythropoeitin, is a synthetic version of a naturally occurring hormone. In the body, the kidneys produce erythropoeitin to stimulate production of red blood cells in the bone marrow. Doctors prescribe synthetic EPO to treat anemia, or low red blood cell count, mainly in people with cancer, AIDS or kidney problems.
For athletes – especially endurance athletes such as cyclists and marathon runners – more red blood cells means more oxygen delivered to the muscles and improved performance.
However, abuse of EPO can cause the body to produce so many red blood cells that the blood becomes too thick for the heart to pump efficiently. This can cause spikes in blood pressure and sudden heart attacks, especially in the middle of the night when the heart's rate is lowest.
EPO use came into the spotlight at the 1998 Tour de France, when French customs officials seized hundreds of doses of EPO and other performance-enhancing drugs from one of the competing teams. The team was disqualified and several other teams withdrew from the race in protest.
Testing for EPO is a challenge because the hormone does occur naturally. Even the effect of EPO, higher red blood cell counts, can occur by natural means, such as high-altitude training.
Even so, the International Cycling Union has imposed a blood test whereby a cyclist would be suspended from racing, for his own safety, if the volume of red blood cells in his blood is greater than 50 per cent.
EPO was such a concern leading up to the Sydney Olympics that officials quickly came up with a test for the hormone. The test involves both blood and urine samples. The blood test looks for high levels of immature red blood cells, indicating that a large amount of the cells were produced recently.
If the number of young blood cells in a sample is too high (the cut-off point is a guarded secret), the athlete's urine is then tested using sophisticated molecular fingerprinting techniques. The urine test is meant to tease out molecular markers present in synthetic EPO that do not occur in the natural hormone.
At the World Track and Field Championships in Edmonton in August, Russian 5,000-meter runner Olga Yegorova was suspended after a positive EPO urine test in July, but the ban was lifted because the required blood test was not also performed.
Yegorova is being tested again in Edmonton before the race.
Yegorova's chief rival, Romania's Gabriela Szabo, has said she is skeptical of the Russian's improvement over the past year. Yegorova has improved her time in the 3,000-meter by 10 seconds.
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