Ethnic differences affect results with existing test, study finds
New steroid doping tests are needed for testing athletes, because current tests ignore important ethnic differences in hormone activity, researchers contend.
Testosterone and other hormones that increase testosterone levels are among the illegal performance-enhancing products most widely used in sports, according to the World Anti-Doping Agency. Evidence of this kind of cheating is determine by the testosterone/epitestosterone ratio (T:E ratio) in urine. The universal threshold is set above four and confirmed by gas chromatography, a type of chemical analysis.
But the current test is inadequate, according to the authors of a new study that tested soccer players of different ethnicities after they deliberately added steroids to their urine samples. The players, ages 18 to 36, included 57 blacks, 32 Asians, 32 Hispanics and 50 whites.
The researchers used gas chromatography to analyze the urine samples and took into account a variation in a gene known to account for different test results between white and Asian men. The gene, UGT2B17, affects metabolism, including the rate at which testosterone is passed out of the body into the urine.
The gene variation was found in 81 percent of the Asian players, 22 percent of the blacks, 10 percent of the whites and 7 percent of the Hispanic players. Based on the findings, the researcher recalibrated the thresholds for each ethnic group and suggested the following T:E ratios: 3.8 for Asian men, 5.6 for black men, 5.7 for white men and 5.8 for Hispanic men.
The study was released online and was expected to be published in a future print issue of the British Journal of Sports Medicine.