Miscellaneous
The Steroidal Module of the Athlete Biological Passport is our greatest weapon in the fight against doping with the naturally produced steroids (Testosterone, Dihydrotestosterone and the prohormones Dehydroepiandrosterone and Androstenedione). The main parameters of the urinary steroid profile are the concentrations and ratios of the testosterone metabolites androsterone (A), etiocholanolone (Etio), 5α-androstane-3α,17β-diol (5α-diol) and 5β-androstane-3α,17β-diol (5β-diol), in addition to epitestosterone (E) (which originates from the biosynthesis of testosterone) and testosterone (T). The ratio of the most importance is the T/E ratio. In the 1980's a T/E ratio of greater than 6 was indicative of testosterone of doping, but in 2004 WADA lowered it to 4, the idea being when you take testosterone it increases the amount of testosterone in your urine but epitestosterone levels are maintained. However in 2008 it was released that individuals who lack two copies of the UGT2B17 gene and thus have no UGT2B17 enzyme, naturally have T/E ratios that are very low and therefore can inject testosterone and never go above the 4/1 cut off. The UGT2B17 enzyme is responsible adding glucuronic acid to testosterone thus enabling it to dissolve in water and be eliminated in the urine, so if you lack this enzyme you don't put much testosterone in your urine, you have a low T/E ratio and can dope and not surpass the 4/1 limit. With the Steroidal Module of the Athlete Biological Passport the T/E ratio (and others) are monitored through time and a sophisticated Bayesian statistical program compares data points to each other to create a individual reference range. If a newly collected data point goes outside of this range you create an Atypical Passport Finding (ATPF) and this result is subsequently investigate by a team of experts. Thus a personalized reference range is created that is far superior to using a population defined threshold of 4 because of the aforementioned genetic confounding factors. Listen to find out more! Make sure you share this podcast with a friend and you leave a positive review if you are enjoying the podcast and please don't forget to subscribe!