Detection of Oral Testosterone Undecanoate Administration in UGT2B17 <i>del/del</i> and <i>del/ins</i> Individuals. Part II: Urinary Endogenous Steroid Sulfate Markers

The detection of endogenous anabolic androgenic steroids misuse in Asian population using the Steroidal Module of the Athlete Biological Passport (ABP) is a challenge due to the high prevalence of UGT2B17 gene deletion polymorphism with low levels of testosterone (T) glucuronide. In this study, the capabilities of different approaches based on urine analysis for the detection of oral T undecanoate administration were evaluated in 13 Asian volunteers, including 11 subjects with del/del genotype and 2 subjects with del/ins genotype. In the first part of the work, the effect on the urinary steroid profile (SP) and on the isotope ratio mass spectrometry markers was evaluated. In this second part, the effect on endogenous sulfate markers was evaluated. Results showed that the oral T administration is detected for a much longer period of time with sulfate markers than with the conventional urinary SP markers. Androstanediol sulfate 1 (Diol-S1)/dehydroandrosterone sulfate (DHA-S) and epiandrosterone sulfate (epiA-S)/DHA-S ratios were the most diagnostic parameters for longitudinal monitoring, as reported for Caucasian volunteers in a previous work. For most subjects, sulfate markers allowed the detection of suspicious samples up to 144 h. Combinations of sulfate and glucuronide markers improved the sensitivity in comparison with the conventional SP markers, but yielded poorer results than the best sulfate ratios. Based on the results of this study and previous works, sulfate EAAS metabolites provide a consistent improvement in the detectability of T administration in both Caucasian and Asian populations. Their incorporation into the ABP should be considered.