Actualité du dopage
Last February, Dutch cyclist Johannes Draaijer died of cardiac arrest a few days after a physician had declared him fit.
Questions surrounding his death linger in the Netherlands, where bicycles are as prominent as canals.
Draaijer’s death has become the catalyst for an official examination of the Netherlands’ cycling program. The Royal Dutch Cycling Federation hopes to find clues to a mystery that has the international medical community’s attention.
At the forefront are rumors that cyclists are using a genetically engineered kidney-disease drug to enhance performances. Some physicians are concerned that the drug, which the body also produces naturally as a hormone, is somehow linked to the deaths, but research does not indicate that.
The practice of blood doping involves the removal of two or three pints of blood about two months before competition, and freezing the red-blood cells. Before competition, the red-blood cells are thawed and injected into the system. The boost of red-blood cells increases oxygen supply to the muscles. Laboratory and field studies show gains in endurance of about 5% from this process.
Rob J. Pluijmers, a sportsmedicine doctor involved with Dutch cyclists for 15 years, admitted last week in Salt Lake City that he knows three professionals taking EPO, a recombinant hormone used to treat anemia. He refused to name the athletes, but this is the first official acknowledgement that athletes are using the drug.
Pluijmers, however, denied that any of the 15 deaths could be attributed to erythropoietin.
“There is no reason to think EPO use is involved,” said Pluijmers who was visiting the United States to speak to colleagues at the American College of Sports Medicine.
Pluijmers said the cyclists he knows using the drug are from the Netherlands and Belgium. He said the three got the drug from sources in Belgium. One athlete, he said, was taking the drug to treat a medical problem, but the others were using it to enhance performance.
EPO is not yet registered in the Netherlands, although it is widely approved throughout Europe. The Food and Drug Administration approved its use in the United States last June. Amgen, a Thousand Oaks firm, developed the drug here.
Three years ago, physicians and pharmacologists stated their concerns about the abuse of erythropoietin among athletes such as cyclists and distance runners who would benefit from blood doping.
Ekblom, credited with discovering blood doping in 1972, said at the time: “This makes it hard to believe in sports’ future.”
Ekblom’s skepticism is shared by many in the medical community who suspect widespread EPO abuse, although it may be years before they can prove it.
E. Randy Eichner, a professor of medicine at Oklahoma State University, said there is no way to differentiate between what the body produces and the synthetic drug.
Although banned by the International Olympic Committee, it is virtually impossible to detect. Researchers say that the injectable drug leaves the body within hours although the oxygen-rich red-blood cells remain for months.
The manufacturer of Epogen, the trademark name for EPO, has been asked to add a genetic marker, making detection possible in a drug test, said James C. Puffer, a U.S. Olympic Committee physician from UCLA. But Eichner said the industry is reluctant for fear of customer complaints over any alterations.
“This could make blood doping obsolete,” said Connie Carpenter-Phinney, a 1984 Olympic gold medalist in cycling who was not involved in the U.S. cycling team’s blood-doping scandal that became public after the Los Angeles Games.
The major concern with EPO is what effects it causes in high dosages. Physicians believe it can cause the blood to become so thick that the heart can no longer pump it. The result would be a heart attack, stroke or blood clot, doctors said.
The drug is considered safe when used properly, and research has not shown any link to sudden cardiac arrest. But as with early studies of anabolic steroids, researchers have not examined the drug’s effects when taken in high dosages, as athletes might be likely to do.
Although doctors have no evidence of EPO use by U.S. athletes, the USOC’s Puffer believes it is a problem.
“It is impossible to know, but I think it is one of our major concerns besides steroids,” he said.
Said Eichner, a blood specialist, “I predict this will be bigger than steroid use for some athletes.”
In the Netherlands, Pluijmers said that autopsies did not offer any clues in the rash of deaths. He added, though, that toxicological tests were not administered.
Draaijer, the Dutch pro who died last February while sleeping, had competed in the Sicilian Week stage race the week of Feb. 18, the start of the spring cycling season.
He fell during the start of competition and complained of a headache and nausea afterward. But Draaijer, who had been one of the Netherlands’ best professionals in recent years, returned three days later to compete after receiving medical approval.
Two days later, he was dead.
Pluijmers said Draaijer died of an aorta outflow disturbance. The flow of blood through the aortic valve, through which the blood flows out of the heart to the body, was obstructed. Pluijmers said the autopsy was not helpful in providing answers as to why, but Draaijer had traces of an echo in his heart two weeks before his death.
Abnormal heart rhythms such as an echo are not uncommon but can indicate problems.
Pluijmers said the country’s attitude changed after Draaijer’s death. Officials finally called for an investigation after a hue and cry in the Dutch press.
“The investigation is ruling out any kind of drug use, but you never know,” Pluijmers said. “It is an unsolved mystery. We have investigated the top 50 cyclists to have an idea of what kind of hearts are beating in these people.”
Pluijmers said they speculate that Dutch cyclists are starting strenuous exercise too young. He said the top pros and amateurs begin at age 8 to 10 and continue until 30.
“We think there is a very big, thin heart, a very slow heart rate,” he said. “I don’t think that’s so good. During sleep, (abnormal) beats can develop. If you have a very relaxed, thin heart, it can sort of flutter . . . causing a dysrhythmia.”
Cardiologists questioned that conclusion, citing many examples of healthy endurance athletes with slow heart rates.
Further, the Dutch are not alone in their passion for cycling.
Dr. Bengt Saltin of the University of Copenhagen said Danish cyclists have similar backgrounds to those in the Netherlands.
“Yet, as far as I know, we have had one death over the years,” he said.
Cardiologists agree with Pluijmers that EPO may not be the culprit, but they say the situation is alarming.
Dr. Tim Noakes of the University of Cape Town in South Africa was astounded by the numbers.
“You tell me there are 15 deaths among cyclists, and I have to tell you immediately it is grossly abnormal,” he said. “It is very unusual to have so many deaths in a defined population.”
Noakes said about one in 7,000 die of sudden cardiac arrest in a population of runners ranging in age from 15 to 55.
“I would suggest something is going on, but I wouldn’t think EPO is necessarily the factor,” he said.
Dutch officials expect to announce results of their investigation in six months.
Pluijmers said preliminary results show the causes of deaths as:
--Four ischemic cases, which are usually traced to coronary artery disease.
--Six post-viral cases in which a cold is suspected of causing cardiomyopathy.
--One Wolff-Parkinson-White syndrome that was diagnosed earlier.
--One aorta outflow disturbance.
Even with the official Dutch conclusion on the way, this is one mystery that may not be unraveled for some time.
Cette page a été mise en ligne le 20/11/2022