Sinkewitz HGH positive remains a rarity

Labelled “a big step in the fight against doping” by UCI spokesman Enrico Carpani, Patrik Sinkewitz’s adverse analytical finding is certainly the first time a cyclist has officially returned a sample positive for human grown hormone (HGH or GH). The blood test, which has been in use since the 2004 Olympic Games in Athens and which was validated in 2007, had appeared not to be efficient and HGH was sometimes said to be “undetectable.”

Against such a backdrop, Sinkewitz’s positive test at the GP Lugano on February 20 might be expected to mark the beginning of regular cases of positive tests for HGH.

However, Dr Martial Saugy, director of the WADA Swiss accredited laboratory in Lausanne, which analyzed Sinkewitz samples, has dampened the UCI’s enthusiasm.

“The detection methods haven’t really changed or improved since 2007 and we’ve always been stunned to find so few positive tests,” he told Cyclingnews. The first athlete suspended for a positive test for HGH was Terry Newton in February 2010. That English international rugby league player committed suicide in September.

Dr. Saugy thinks that the myth of undetectable growth hormones offers a partial explanation of Sinkewitz’s positive test. “In that case, riders let up on their attention and they are caught,” he said. This supports the UCI’s stance in keeping the development of the HGH test as a secret, and the international federation never officially announced when it began looking for the substance in the cyclists’ samples.

The HGH test is very delicate to run because of the short detection window of the substance in the human body, of between 8 and 24 hours. “We have to test the riders at the right moment,” Dr Saugy said. It is thus understandable that the biological passport is still helpful for targeting suspicious cyclists and testing them in and out competition.

Growth hormone drugs appeared in the 1950s to support a cure for dwarfism. At that time they came from pituitary glands removed from human cadavers, a technique that is now forbidden in a bid to avoid Creutzfeld-Jacob disease. That medical substance’s properties that lend it to doping, include its ability to increase lean muscle mass and increase resistance to injury.

The Italian athlete Pietro Mennea, the 200 metre Olympic champion in Moscow in 1980, admitted that he used HGH during his career, while in 1988, a new recombinant form of growth hormone, synthesized in a laboratory, was placed on the market. The following year, the International Olympic Committee added GH to its doping list.

French anti-doping expert Professor Gerard Dine, a haematologist and one of the founders of biological passport, says that HGH is traditionally used by cheats as a “pre-season course.” There is also another growth hormone, IGF-1, which can be illegally taken between competitions by speed sports athletes, in order to fix the muscles damaged by the high efforts.

“The positive GH test in cycling is encouraging,” Pr Dine told Cyclingnews. “Perhaps the athletes who used that will be scared and will change their habits.” But the French expert is cautious too: “The GH test is still complicated to do and we still have to strongly target the athletes. What is more, the IGF-1 test is even more subtle...”

Farnese Vini-Neri’s Patrik Sinkewitz, 30 years old, already tested positive for testosterone in June 2007 and served a suspension. He came back to competition in November 2008, and has since won the Sachsen Tour and a stage in the Tour of Portugal in 2009, as well as the Giro della Romagna in 2010. He retains the right to request an analysis of the B sample of his second positive test.

The HGH Test

The test for HGH is complicated because the drug is made (using recombinant DNA technology) to be identical to that already made by the human body.

The amounts made by the body and those taken (and released into the urine after administration) are very low, making development of a sensitive and accurate test difficult.

Adding to the degree of difficulty is distinguishing synthetic HGH from normal (endogenous) HGH. Studies have shown that there are two sizes of the protein in the body, and normally a heavier version of the protein (22kDa) abounds, but there is a lighter version floating around (20kDa). When someone takes synthetic HGH, nearly all of the substance in the urine is of the heavier variety.

This fine distinction makes pursuing a doping case difficult, if not from a technical standpoint, then certainly from a legal one.

To validate the test, rigorous studies have been performed in order to make for a more solid legal argument for a positive result.

The UCI used a blood test on Sinkewitz, but a urine test has been in development since 2008.

In early 2009 it was reported that the US Anti-doping Agency (USADA) was working together with the company Ceres to help validate the effectiveness of detecting synthetic HGH in athletes, with USADA giving researchers $65,000 to help demonstrate this in real-world conditions.

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