Steroid profiles of professional soccer players: an international comparative study.
OBJECTIVE
Urinary steroid profiling is used in doping controls to detect testosterone abuse. A testosterone over epitestosterone (T/E) ratio exceeding 4.0 is considered as suspicious of testosterone administration, irrespectively of individual heterogeneous factors such as the athlete's ethnicity. A deletion polymorphism in the UGT2B17 gene was demonstrated to account for a significant part of the interindividual variability in the T/E between Caucasians and Asians. Here, the variability of urinary steroid profiles was examined in a widely heterogeneous cohort of professional soccer players.


METHODS
The steroid profile of 57 Africans, 32 Asians, 50 Caucasians and 32 Hispanics was determined by gas chromatography-mass spectrometry.


RESULTS
Significant differences have been observed between all ethnic groups. After estimation of the prevalence of the UGT2B17 deletion/deletion genotype (African: 22%; Asian: 81%; Caucasian: 10%; Hispanic: 7%), ethnic-specific thresholds were developed for a specificity of 99% for the T/E (African: 5.6; Asian: 3.8; Caucasian: 5.7; Hispanic: 5.8). Finally, another polymorphism could be hypothesised in Asians based on specific concentration ratio of 5alpha-/5beta-androstane-3alpha,17beta-diol in urine.


CONCLUSIONS
These results demonstrate that a unique and non-specific threshold to evidence testosterone misuse is not fit for purpose. An athlete's endocrinological passport consisting of a longitudinal follow-up together with the ethnicity and/or the genotype would strongly enhance the detection of testosterone abuse. Finally, additional genotyping studies should be undertaken to determine whether the remaining unexplained disparities have an environmental or a genetic origin.
Strahm
E
E
Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, West Switzerland, Chemin des Croisettes 22, Epalinges, Switzerland.
Sottas
P-E
PE
Schweizer
C
C
Saugy
M
M
Dvorak
J
J
Saudan
C
C
D000293:Adolescent; D000328:Adult; D004300:Doping in Sports / Q000517:prevention & control*; D008401:Gas Chromatography-Mass Spectrometry; D017353:Gene Deletion; D005838:Genotype; D014453:Glucuronosyltransferase / Q000235:genetics; D006801:Humans; D008297:Male; D015778:Minor Histocompatibility Antigens; D011110:Polymorphism, Genetic / Q000235:genetics; D044469:Racial Groups / Q000235:genetics*; D012016:Reference Values; D012916:Soccer; D013256:Steroids / Q000652:urine*; D015813:Substance Abuse Detection / Q000379:methods*; D055815:Young Adult
D015778:Minor Histocompatibility Antigens; D013256:Steroids; D014453:Glucuronosyltransferase; C500513:UGT2B17 protein, human