Martín Escudero, María Del PilarMuñoz Guerra, Jesús A.Vargas García-Tenorio, SoledadSerrano Garde, EsterSoldevilla Navarro, Ana B.Galindo Canales, MercedesPrado, NayadeFuentes Ferrer, Manuel E.Fernández Pérez, Cristina2025-01-292025-01-292018-11-29Martín-Escudero, P., Muñoz-Guerra, J. A., García-Tenorio, S. V., Garde, E. S., Soldevilla-Navarro, A. B., Galindo-Canales, M., Prado, N., Fuentes-Ferrer, M. E., & Fernández-Pérez, C. (2019). Impact of the UGT2B17 polymorphism on the steroid profile. Results of a crossover clinical trial in athletes submitted to testosterone administration. Steroids, 141, 104–113. https://doi.org/10.1016/j.steroids.2018.11.0090039-128X10.1016/j.steroids.2018.11.009https://hdl.handle.net/20.500.14352/116740Subprograma DEPOThis article studies the genetic influence of polymorphism of the UGT2B17 gen on the urinary steroid profile and its implications for the anti-doping field. The study presents the results of a triple-blind randomized placebo-controlled crossover trial with healthy athletes submitted to a single dose of 250 mg of testosterone cypionate. Forty urine samples were collected from each participant. Mass spectrometry-based techniques commonly used in Anti-Doping laboratories, were employed to measure the urinary concentration and the Δδ13C values of a selection of target compounds for testosterone (T) administration together with LH. Twelve volunteers were included in the study; the polymorphism was evenly distributed among them. After T administration, the most meaningful change affected the Testosterone/Epitestosterone ratio (T/E) and the urinary concentration of LH. In relation with T/E, the wild type homozygous (ins/ins) group there was a mean relative increase of 30 (CI 95%: 25.2 to 36.7); in the heterozygous mutant (del/ins) group it was 19.8 (CI 95%:15.9 to 24.7); and in the homozygous mutant (del/del) group it was 19.7 (CI 95% 14.9 to 26.2). In the case of LH, it́s observed how LH values decrease significantly after the administration of Testex homogeneously among the three groups. The main outcome was related to the (del/del) group (homozygous mutant), where due to the depressed basal level of the steroid profile, if the longitudinal steroid profile of the athlete was not available, the analysis by GC/MS would not produce an “atypical” result according to the WADA TD2016EAAS despite the T administration. However, the genotyping of the UGT2B17 polymorphism, the follow up of LH and the use of GC-C-IRMS makes it possible to identify most of these samples as Adverse.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/journal articlehttps://doi.org/10.1016/j.steroids.2018.11.009https://www.sciencedirect.com/science/article/pii/S0039128X18302137?via%3Dihubopen access61I12DopingUGT2B17 GenotypeSteroid ProfileTestosterone AdministrationSportLutenizating hormoneExerciseMedicina del deporte2411.06 Fisiología del Ejercicio