Endocrine Insider
April 17, 2008

A recent news release by The Endocrine Society has received international attention. As reported in The Washington Post, The Economist, Science News, and a number of other publications, the tests for testosterone doping commonly used in professional and amateur sports may routinely be confounded by an individual’s genetic make-up. Accepted for publication in the Journal of Clinical Endocrinology & Metabolism (JCEM), this new study suggests that unless a common genetic variation is accounted for, current testing methods could implicate innocent athletes and allow cheaters to go undetected.

According to lead author Jenny J. Schulze, PhD, of the Karolinska University Hospital in Stockholm, nearly half of the individuals in the study who carried one type of genetic variation would go undetected in a regular doping test after a single 360 mg dose of testosterone. Of those who carry a different type of genetic variation, 14 percent were naturally over the detection threshold even without receiving a testosterone injection. Based on an earlier study, Schulze and her colleagues estimate that this would give a false-positive rate of 9 percent in a random population of young men.

The paper “Doping Test Results Dependent on Genotype of UGT2B17, the Major Enzyme for Testosterone Glucuronidation” will appear in the June issue of JCEM, a publication of The Endocrine Society.

The report in The Economist is here: