Androgen Sulfation in Healthy UDP-Glucuronosyl Transferase 2B17 Enzyme-Deficient Men

Abstract

The conspicuous interindividual differences in metabolism and urinary excretion of testosterone and its metabolites make it challenging to reveal testosterone doping. The variation in testosterone glucuronide excretion is strongly associated with a deletion polymorphism in the uridine diphosphate-glucuronosyltranferase (UGT) 2B17 gene. The objective of the study was to identify additional biomarkers to detect testosterone abuse and to elucidate alternative pathways for testosterone elimination in individuals devoid of the UGT2B17 enzyme. For this purpose a new ultraperformance liquid chromatographic tandem mass spectrometric method for simultaneous determination of 10 different sulfo- and glucuronide-conjugated steroids was developed. Fifty-four healthy male volunteers with two, one, or no allele (ins/ins, ins/del, or del/del) of the UGT2B17 gene participated in the study. Intervention included a single im dose of 500 mg testosterone enanthate. Urinary sulfo- and glucuronide-conjugated steroids were measured. Testosterone sulfate levels decreased in all individuals after the dose. The individual differences in the excretion of all sulfated metabolites were large. Thus, these metabolites will not serve as appropriate biomarkers for testosterone abuse. However, androsterone glucuronide excretion increased in all of our study subjects after the testosterone dose. Etiocholanolone sulfate was excreted at significantly higher levels in UGT2B17 del/del individuals. We propose that the androsterone glucuronide to epitestosterone glucuronide ratio may serve as a complementary biomarker to reveal testosterone abuse.