UDP‐glucuronosyltransferase 2B17 genotyping in Japanese athletes and evaluation of the current sports drug testing for detecting testosterone misuse

Abstract

Ethnicity has been found to influence urinary testosterone glucuronide to epitestosterone glucuronide (T/E) ratios among athletes. Uridine diphospho-glucuronosyltransferase 2B17 (UGT2B17) is the most active enzyme in testosterone glucuronidation. UGT2B17 polymorphism analysis is rarely performed in Japanese athletes, and the influence of testosterone administration on steroid profiles and carbon isotope ratios, according to gene polymorphisms, in Asians remains unknown. The prevalence of UGT2B17 genotypes and urinary androgenic steroid profiles, classified according to UGT2B17 genotypes, was investigated in Japanese athletes (255 male and 256 female). Testosterone enanthate (100 mg) was administered intramuscularly to Japanese female volunteers (del/del: n = 6, del/ins: n = 3, ins/ins: n = 1). The distribution rates of the UGT2B17 del/del genotype in Japanese male and female athletes were 74.5% and 60.2%, respectively. The ins/ins genotype was detected in only three male (1.2%) and seven female (2.7%) athletes. The prevalence of the UGT2B17 deletion genotype was extremely high in Japanese athletes. The T/E ratio in the del/del group was significantly lower than that in the other groups. After testosterone was administered to female volunteers, the T/E ratios for the del/del individuals failed to reach the positivity criterion of 4. By contrast, in all of the del/del subjects, the gas chromatography/combustion/isotope ratio mass spectrometry (GC-C-IRMS) analysis successfully fulfilled the positivity criterion. The overall result has demonstrated the limited effectiveness of population-based T/E ratios in screening tests for testosterone use. Subject-based steroid profiling with UGT2B17 genotyping will be an effective strategy for detecting testosterone misuse.

The Impact of Genetics and Hormonal Contraceptives on the Steroid Profile in Female Athletes

“…A 29% increase in T/E ratio could be discerned first after the individuals homozygous for the deletion polymorphism in UGT2B17 were excluded. Furthermore, our results confirm a strong link between UGT2B17 deletion polymorphism and urinary testosterone levels in our female study group (9, 26). Here we show for the first time a link between a SNP in the promoter region of CYP17 and epitestosterone excretion in females.…”

“…The ratio of A/Etio and 5α-diol/5β-diol does not seem to be affected during HC application, which is important for doping control purposes. However, the 5α-diol/5β-diol ratio, an important marker for dihydrotestosterone doping (40), is affected by the UGT2B17 deletion polymorphism (12, 26, 41) as 5β-diol is mainly glucuronidated by UGT2B17 (8). We and others have reported that A/E ratio is a sensitive marker for testosterone doping.…”

Genotype‐dependent metabolism of exogenous testosterone – new biomarkers result in prolonged detectability

“…[6][7][8] In these individuals, the glucuronidation of T is significantly decreased resulting in low natural T/E ratios that are only slightly elevated after illicit T administration. [11,14] Consequently, further information on the T metabolism in consideration of the different UGT2B17 genotypes has been desirable. [9][10][11] Neither the implementation of an expanded steroid profile taking sulphoconjugated (SULF) T and E into account nor a steroidomics approach could clearly show how administered T is preferentially excreted if not as T-GLUC.…”

Determination of mepitiostane metabolites in human urine by liquid chromatography/tandem mass spectrometry for sports drug testing

“…Crystallised epitiostanol sulfoxide (1.7 mg, 24% yield) was obtained and identified by NMR spectroscopy with 1 H, 13 Differences in 13 C chemical shifts between epitiostanol and the corresponding sulfoxide ( ıC in ppm) were −4.80 (C-1), 16.06 (C-2), 15.45 (C-3), −5.04 (C-4) and 5.37 (C-5). These chemical shifts were consistent with the occurrence of a sulphur atom attached to the more electronegative oxygen atom.…”

“…Urine samples were prepared according to the common steroid analytical procedure validated for sports doping tests [16]. In brief, 3 mL of human urine fortified with 50 l of I.S.…”