Athlete Biological Passport, Steroids and Pain Killers – Does hydroxysteroid dehydrogenase inhibition by nonsteroidal anti-inflammatory drugs alter the steroid profile?

Code: ISF16D20FB 

The Athlete Biological Passport (ABP) represents an integral part of the anti-doping analyses. In the fight against doping, laboratories rely on monitoring blood and steroid profile data to set up long-term, individualized profiles of athletes. To uncover a prohibited administration of pseudoendogenous steroids (class S1.1 of the WADA “List of Prohibited Substances and Methods”) laboratories monitor concentrations and ratios of various endogenously produced steroidal hormones, their precursors, and metabolites for almost 25 years. Several studies reported only very small naturally occurring intra-individual variations of urinary endogenous steroid ratios like testosterone/epitestosterone (T/EpiT), androsterone/etiocholanolone (And/Etio), And/T, and 5α-/5β-androstane-3α,17β-diol (Adiol/Bdiol), that have been shown to be stable over months and even years in adult humans. In cases of a misuse of pseudoendogenous steroids as doping substances, these ratios are altered. Thus, the ABP is used to uncover a prohibited administration of class S1.1 steroids. However, it was shown recently that some other (non-prohibited) drugs may also influence the urinary steroid profile. In this project we focus our attention on the class of non steroidal anti inflammatory drugs (NSAIDs) that are frequently used as pain killers and antiphlogistics. Specifically, NSAIDs have been shown to inhibit the steroid metabolizing aldo-keto-reductases (AKR) 1C, namely the 3α-hydroxysteroid dehydrogenase (AKR1C2) and the 17β-hydroxysteroid dehydrogenase (AKR1C3). As no scientific data on the influence of these inhibitory NSAIDs on urinary steroids are available from literature, the project aims to close this gap.

Main findings

The Athlete Biological Passport (ABP) represents an integral part of anti-doping analyses. In the fight against doping, WADA accredited laboratories rely on monitoring blood and steroid profile data to set up long-term, individualized profiles of atheletes using the so called "hematological module" (in whole blood samples) and "steroidal module" (in urine samples). The alteration of one or more parameters of the passport can indeed be the effect of the recourse to doping substances and/or methods. More specifically, the monitoring of the hematological module can reveal the recourse to different forms of "blood doping" (transfusion, synthetic hemoglobins, illicit intake of erythropoiesis stimulating agents) while the steroidal module is used to unearth the administration of testosterone, its precursors and other "pseudo-endogenous" steroids (that are endogenous steroids when administered exogenously). The correct evaluation and interpretation of data obtained in the analysis of the ABP modules require the identification of any "confounding factors", that is non-prohibited substances that can alter the reliability of the ABP measurement.

In this project, we specifically considered the potential effects on markers of the steroidal module of the ABP of the use of "pain killers", that is non-prohibited drugs belonging to the class of non-steroidal anti-inflammatory drugs (NSAIDS). These substances are very commonly used by the athletes of virtually all sports/sport disciplines so it seemed to us of the utmost importance to verify whether their intake could cause an alteration in one or more parameters of the steroidal module of the ABP.

The project was structured along two parallel research lines:

• the in vitro evaluation of the inhibitory effect of NSAIDs (assessed on the prototype compound ibuprofen) on the activity of hydroxysteroid reductases, that is enzymatic systems involved in the biometabolic pathways of testosterone and other endogenous androgenic anabolic steroids;

• the analysis of urine samples obtained from controlled administration studies, performed collecting the urine samples before, during, and after a two-week period of intake of a daily, therapeutic dose of either ibuprofen or indomethacin, to verify the effects over time on the urinary steroid profile, and, at the same time, to identify and quantitate suitable markers of NSAID intake, i.e. the parent drug itself and/or its main metabolite(s).

Our findings confirm that both ibuprofen and indomethacin can act as "confounding factors" of the steroidal module of the ABP, altering the measured concentrations and concentration ratios of key markers of the steroid profile. This finding was more evident in the female subject than in the males; such an inter-gender difference was more evident for ibuprofen than for indomethacin. Should the results obtained in the present project be confirmed on a more statistically significant number of subjects, of both sexes and ideally of different ethnicities, NSAIDs could be considered for inclusion among the "confounding factors" of the steroidal module of the ABP.