Longitudinal evaluation of multiple biomarkers for the detection of testosterone gel administration in women with normal menstrual cycle

In women, hormonal fluctuations related to the menstrual cycle may impose a great source of variability for some biomarkers of testosterone (T) administration, which can ultimately disrupt the sensitivity of their longitudinal monitoring. In this study, the sensitivity of the current urinary and haematological markers of the Athlete Biological Passport (ABP), as well as serum steroid biomarkers, was investigated for the monitoring of a 28-day T gel treatment combined with endogenous fluctuation of the menstrual cycle in 14 healthy female subjects. Additionally, the analysis of urinary target compounds was performed on a subset of samples for endogenous/exogenous origin via isotope ratio mass spectrometry (IRMS). In serum, concentrations of T and dihydrotestosterone (DHT) increased significantly during the treatment, whereas in urine matrix the most affected biomarkers were found to be the ratios of testosterone/epitestosterone (T/E) and 5α-androstane-3α,17β-diol/epitestosterone (5αAdiol/E). The detection capability of both urinary biomarkers was heavily influenced by [E], which fluctuated depending on the menstrual cycle, and resulted in low sensitivity of the urinary steroidal ABP module. On the contrary, an alternative approach by the longitudinal monitoring of serum T and DHT concentrations with the newly proposed T/androstenedione ratio showed higher sensitivity. The confirmatory IRMS results demonstrated that less than one third of the tested urine samples fulfilled the criteria for positivity. Results from this study demonstrated that the ‘blood steroid profile’ represents a powerful complementary approach to the ‘urinary module’ and underlines the importance of gathering bundle of evidence to support the scenario of an endogenous prohibited substance administration.     

Evaluation of blood parameters by linear discriminant models for the detection of testosterone administration

The steroidal module of the Athlete Biological Passport (ABP) has been used since 2014 for the longitudinal monitoring of urinary testosterone and its metabolites to identify samples suspicious for the use of synthetic forms of Endogenous Anabolic Androgenic Steroids (EAAS). Multiple recent studies have suggested that monitoring of blood parameters may provide enhanced detectability of exogenous testosterone administration. Transdermal and intramuscular testosterone administration studies were carried out in 15 subjects, and the effect on blood steroidal levels, hematological parameters, and gonadotropins was evaluated. Serum testosterone and dihydrotestosterone levels increased while gonadotropin levels were suppressed after administration. A modest increase in reticulocytes was also observed. The blood parameters that were responsive to the administrations were combined into several linear discriminant models targeting both administration (on) and washout (off) phases. The models were effective in detecting the large dose intramuscular administration but were less successful in the detection of the lower dose transdermal application. The blood profiling models may provide complementary value but do not appear to be substantially more advantageous than longitudinal urinary profiling.     

Changes in blood parameters after intramuscular testosterone ester injections – Implications for anti‐doping

Testosterone treatment stimulates the production of red blood cells and alters iron homeostasis. Thus, we investigated whether the ‘haematological module’ of the athlete biological passport (ABP) used by the World Anti‐Doping Agency can be used to indicate misuse of testosterone. Nineteen eugonadal men received intramuscular injections of either 250 mg Sustanon®, a blend of four testosterone esters, or placebo on days 0 and 21 in a randomized, placebo‐controlleddouble‐blind design. Urine samples and blood samples were collected twice pre‐treatment, at least 5 days apart, and on days 1, 3, 5, 10 and 14 post‐injections to assess steroidal and haematological biomarkers of the ABP. The steroidal profile was flagged suspicious in all Sustanon®‐treated subjects, whereas the haematological profile was flagged suspicious in six out of nine subjects. When both sensitivity and specificity were considered, reticulocyte percentage (RET%) appeared as the best marker of the haematological module for implying testosterone ester misuse. Atypical blood passport samples were used to select time points for further isotope‐ratio mass spectrometry (IRMS) analysis of testosterone and its metabolites in simultaneously collected urine. In addition to the testosterone (T) to epitestosterone (E) ratio, the RET% and OFF‐Score could help identify suspicious samples for more targeted IRMS testing. The results demonstrate that unexpected fluctuations in RET% can indicate testosterone doping if samples are collected 3–10 days after injection. From an anti‐doping perspective, the haematological and steroidal modules of the ABP should complement each other when planning targeted follow‐up testing and substantiating likely misuse of testosterone.     

Codeine influences the serum and urinary profile of endogenous androgens but does not interact with the excretion rate of administered testosterone

Today's doping tests involve longitudinal monitoring of urinary steroids including the testosterone glucuronide and epitestosterone glucuronide ratio (T/E) in an Athlete Biological Passport (ABP). The aim of this study was to investigate the possible influence of short‐term use of codeine on the urinary excretion of androgen metabolites included in the steroidal module of the passport prior to and after the co‐administration with testosterone. The study was designed as an open study with the subjects being their own control. Fifteen healthy male volunteers received therapeutic doses of codeine (Kodein Meda) for 6 days. On Day 3, 500 mg or 125 mg of testosterone enanthate (Testoviron®‐Depot) was administered. Spot urine samples were collected for 17 days, and blood samples were collected at baseline, 3, 6, and 14 days after codeine intake. The circulatory concentration of total testosterone decreased significantly by 20% after 3 days' use of codeine (p = 0.0002) and an atypical ABP result was noted in one of the subjects. On the other hand, the concomitant use of codeine and testosterone did not affect the elevated urinary T/E ratio. In 75% of the individuals, the concentration of urinary morphine (a metabolite of codeine) was above the decision limit for morphine. One of the participants displayed a morphine/codeine ratio of 1.7 after codeine treatment, indicative of morphine abuse. In conclusion, our study shows that codeine interferes with the endogenous testosterone concentration. As a result, the urinary steroid profile may lead to atypical findings in the doping test.     

Urinary steroid profile in females – the impact of menstrual cycle and emergency contraceptives

Today's doping tests involving longitudinal monitoring of steroid profiles are difficult in women. Women have more complex hormonal fluctuations than men and commonly take drugs such as hormonal contraceptives that are shown to affect biomarkers used in these doping tests. In this study, we followed six women's urinary steroid profile during one menstrual cycle, including both glucuronides and sulfate conjugated fractions. Additionally, we studied what happens to the steroidal module of the Athlete Biological Passport (ABP) after administration of an emergency contraceptive (levonorgestrel, NorLevo®). The study shows that there are large individual variations in all metabolites included in the ABP and that the administration of emergency contraceptives may lead to suspicious steroid profile findings in the ABP. Urinary epitestosterone concentration increased during the menstrual cycle, leading to a decrease in the testosterone/epitestosterone ratio. The ratios followed in the ABP varied widely throughout the menstrual cycle, the coefficient of variation (CV) ranging from 4 to 99%. There was a 3‐fold decrease in epitestosterone 24 h post administration of the emergency contraceptive pill and androsterone, etiocholanolone, and 5β‐ androstan‐3α,17β‐diol concentrations decreased about 2‐fold. When analyzed with the ABP software, one of the six women had an atypical profile after taking the emergency contraceptive. Furthermore, we could not find any alterations in excretion routes (i.e., if the metabolites are excreted as glucuronide or sulfate conjugates) during the menstrual cycle or after administration of emergency contraceptive, indicating no direct effect on phase II enzymes. Copyright © 2016 John Wiley & Sons, Ltd.     

Sensitivity of doping biomarkers after administration of a single dose testosterone gel

Micro‐doping with testosterone (T) is challenging to detect with the current doping tests. Today, the methods available to detect T are longitudinally monitoring of urine biomarkers in the Athlete Biological Passport (ABP) and measuring the isotopic composition of excreted biomarkers to distinguish the origin of the molecule. In this study, we investigated the detectability of a single dose of 100 mg T gel in 8 healthy male subjects. We also studied which biomarkers were most sensitive to T gel administration, including blood biomarkers. The ABP successfully detected T gel administration in all 8 subjects. The most sensitive ratio was 5αAdiol/E, however, all ratios showed atypical findings. Isotope ratio mass spectrometry (IRMS) was performed on 5 subjects and only 2 met all the criteria for a positive test according to the rules set by the World Anti‐Doping Agency (WADA). The other 3 showed inconclusive results. Other markers that were affected by T gel administration, not used for this detection today, were serum dihydrotestosterone (DHT) and T as well as reticulocyte count and percentage in whole blood. miRNA‐122 was not significantly affected by the single T dose. A single dose of 100 mg T gel is possible to detect with today's doping tests. Since a single dose of T gel has an impact on some hematological biomarkers, access to both modules of the ABP when evaluating the athletes' profiles will increase the possibility to detect micro‐doses of T. In addition, serum DHT and T may be a useful addition to the future endocrine module of the ABP.     

Intra-individual stability of longitudinal urinary steroid profiles in Swedish athletes

The steroid module of the athlete biological passport (ABP) aims to detect doping with endogenous steroids by longitudinally monitoring epitestosterone (E), testosterone (T), and four metabolically related steroids and their ratios. There are large variations in the urinary levels of the androgen metabolites due to genetic polymorphisms, drug use, menstrual cycle, and other factors. In this study, we aimed to increase our understanding of the natural, within-individual variations of the established ABP markers in males and females over time, looking at samples collected both in and out-of-competition (IC/OOC). Urinary steroid profiles from 323 Swedish athletes, with at least five samples per athlete, were extracted from ADAMS together with information on type of sport, IC/OOC, and time of day. Data were analyzed using coefficient of variation (CV%) to examine within-subject variability and linear mixed effects models to estimate within-subject change in the metabolites over time. The metabolites and ratios expressed higher individual CV% in females (23–56) than in males (18–39). Samples taken OOC showed larger intra-individual variations than samples collected IC for most of the ABP metabolites in both sexes. The median concentrations were higher IC for some metabolites, particularly testosterone being 52% higher among females. Time of day influenced the intra-individual variation of the urinary steroid profile with decreases in androgen metabolites over time, if measured in evening versus daytime. These findings can aid in the testing strategies and interpretation of the steroidal module of ABP.     

Variability of the urinary and blood steroid profiles in healthy and physically active women with and without oral contraception

The steroidal module of the athlete biological passport (ABP) targets the use of pseudo-endogenous androgenous anabolic steroids in elite sport by monitoring urinary steroid profiles. Urine and blood samples were collected weekly during two consecutive oral contraceptive pill (OCP) cycles in 15 physically active women to investigate the low urinary steroid concentrations and putative confounding effect of OCP. In urine, testosterone (T) and epitestosterone (E) were below the limit of quantification of 1 ng/ml in 62% of the samples. Biomarkers' variability ranged between 31% and 41%, with a significantly lesser variability for ratios (except for T/E [41%]): 20% for androsterone/etiocholanolone (p < 0.001) and 25% for 5α-androstane-3α,17β-diol/5ß-androstane-3α,17β-diol (p < 0.001). In serum, markers' variability (testosterone: 24%, androstenedione: 23%, dihydrotestosterone: 19%, and T/A4: 16%) was significantly lower than in urine (p < 0.001). Urinary A/Etio increased by >18% after the first 2 weeks (p < 0.05) following withdrawal blood loss. In contrast, serum T (0.98 nmol/l during the first week) and T/A4 (0.34 the first week) decreased significantly by more than 25% and 17% (p < 0.05), respectively, in the following weeks. Our results outline steroidal variations during the OCP cycle, highlighting exogenous hormonal preparations as confounder for steroid concentrations in blood. Low steroid levels in urine samples have a clear negative impact on the subsequent interpretation of steroid profile of the ABP. With a greater analytical sensitivity and lesser variability for steroids in healthy active women, serum represents a complementary matrix to urine in the ABP steroidal module.     

Evaluation of longitudinal steroid profiles from male football players in UEFA competitions between 2008 and 2013

Testosterone and related compounds are the most recurrent doping substances. The steroid profile, consisting of the quantification of testosterone and its metabolites, has been described as the most significant biomarker to detect doping with pseudo‐endogenous anabolic steroids. The steroidal module of the Athlete Biological Passport (ABP) was launched by the World Anti‐Doping Agency (WADA) in 2014. To assess the value of introducing the module to its anti‐doping programme, the Union of European Football Associations (UEFA) decided to analyze retrospectively the steroid profile data of 4195 urine samples, collected from 879 male football players and analyzed in 12 WADA‐accredited laboratories between 2008 and mid‐2013. This study focused on the evaluation of T/E ratios. The coefficient of variation (CV) and the adaptive model were the two statistical models used to study the longitudinal follow‐up. A CV of 46% was determined to be the maximal natural intra‐individual variation of the T/E when the sequence consisted of single data points analyzed in different laboratories. The adaptive model showed some profiles with an atypical T/E sequence and also enabled an estimate of the prevalence of external factors impacting the T/E sequences. Despite the limitations of this retrospective study, it clearly showed that the longitudinal and individual follow‐up of the T/E biomarker of the players is a good tool for target testing in football. UEFA has therefore decided to implement the steroidal module of the ABP from the start of the next European football season in September 2015. Copyright © 2015 John Wiley & Sons, Ltd.     

Reporting and managing elevated testosterone/epitestosterone ratios--novel aspects after five years' experience

The testosterone/epitestosterone (T/E) ratio was implemented as an indirect parameter for the detection of testosterone administration with an empirically established threshold value at T/E = 6. In 2005, the T/E reporting threshold was lowered from six to four. Between 2005 and 2009, 63 510 doping control urine samples were analyzed in the Cologne laboratory. A total of 1442 specimens (2.3%) showed a T/E > 4; 80 (5.5%) of which were tested positive by means of isotope ratio mass spectrometry (IRMS); and most of which (68) originated from strength sport disciplines. Specimens of high T/E ratio showed a much higher probability for being confirmed to contain exogenous testosterone using IRMS analysis than samples of low T/E values. Considering the small number of adverse analytical findings triggered by lowering the T/E reporting threshold (978 urine specimens with T/E ratios between 4 and 6 yielded only 4 (0.4%) positive IRMS findings) and the known limitations of the T/E ratio as discriminating parameter (UGT2B17 polymorphism), the currently mandatory approach shows only marginal overall efficiency. A more effective tool for the detection of the misuse of testosterone would be the implementation of individual reference ranges. Until athlete steroidal passports are available, it is suggested to exceed the threshold level for T/E from 4 to 6 and perform obligatory IRMS analysis for specimens showing T/E > 6. Further conditions triggering IRMS analysis could be suppressed luteinizing hormone (LH) values in males and disproportionate changes of relevant parameters in individual profiles evidently not resulting from ethanol consumption.     

Sensitive detection of testosterone and testosterone prohormone administrations based on urinary concentrations and carbon isotope ratios of androsterone and etiocholanolone

The testing strategy for the detection of testosterone (T) or T-prohormones is based on the longitudinal evaluation of urinary steroid concentrations accompanied by subsequent isotope ratio mass spectrometry (IRMS)-based confirmation of samples showing atypical concentrations or concentration ratios. In recent years, the IRMS methodology focussed more and more on T itself and on the metabolites of T, 5α- and 5β-androstanediol. These target analytes showed the best sensitivity and retrospectivity, but their use has occasionally been challenging due to their comparably low urinary concentrations. Conversely, the carbon isotope ratios (CIR) of the main urinary metabolites of T, androsterone (A) and etiocholanolone (EITO), can readily be measured even from low urine volumes; those however, commonly offer a lower sensitivity and shorter retrospectivity in uncovering T misuse. Within this study, the CIRs of A and ETIO were combined with their urinary concentrations, resulting in a single parameter referred to as ‘difference from weighted mean’ (DWM). Both glucuronidated and sulfated steroids were investigated, encompassing a reference population (n = 110), longitudinal studies on three individuals, influence of ethanol in two individuals, and re-analysis of several administration studies including T, dihydrotestosterone, androstenedione, epiandrosterone, dehydroepiandrosterone, and T-gel. Especially DWM calculated for the sulfoconjugated steroids significantly prolonged the detection time of steroid hormone administrations when individual reference ranges were applied. Administration studies employing T encompassing CIR common for Europe (−23.8‰ and −24.4‰) were investigated and, even though for a significantly shorter time period and less pronounced, DWM could demonstrate the exogenous source of T metabolites.     

Pregnancy greatly affects the steroidal module of the Athlete Biological Passport

Concentrations of urinary steroids are measured in anti‐doping test programs to detect doping with endogenous steroids. These concentrations are combined into ratios and followed over time in the steroidal module of the Athlete Biological Passport (ABP). The most important ratio in the ABP is the testosterone/epitestosterone (T/E) ratio but this ratio is subject to intra‐individual variations, especially large in women, which complicates interpretation. In addition, there are other factors affecting T/E. Pregnancy, for example, is known to affect the urinary excretion rate of epitestosterone and hence the T/E ratio. However, the extent of this variation and how pregnancy affect other ratios has not been fully evaluated. Here we have studied the urinary steroid profile, including 19‐norandrosterone (19‐NA), in 67 pregnant women and compared to postpartum. Epitestosterone was higher and, consequently, the T/E and 5αAdiol/E ratios were lower in the pregnant women. Androsterone/etiocholanolone (A/Etio) and 5αAdiol/5βAdiol, on the other hand, were higher in the first trimester as compared to postpartum (p<0.0001 and p=0.0396, respectively). There was no difference in A/T during pregnancy or after. 19‐NA was present in 90.5% of the urine samples collected from pregnant women. In this study, we have shown that the steroid profile of the ABP is affected by pregnancy, and hence can cause atypical passport findings. These atypical findings would lead to unnecessary confirmation procedures, if the patterns of pregnancy are not recognized by the ABP management units.     

Inter‐individual variation of the urinary steroid profiles in Swedish and Norwegian athletes

The steroidal module of the Athlete Biological Passport (ABP) aims to detect doping with endogenous steroids, e.g. testosterone (T), by longitudinally monitoring several biomarkers. These biomarkers are ratios combined into urinary concentrations of testosterone and metabolically related steroids. However, it is evident after 5 years of monitoring steroid passports that there are large variations in the steroid ratios complicating its interpretation. In this study, we used over 11000 urinary steroid profiles from Swedish and Norwegian athletes to determine both the inter‐ and intra‐individual variations of all steroids and ratios in the steroidal passport. Furthermore, we investigated if the inter‐individual variations could be associated with factors such as gender, type of sport, age, time of day, time of year, and if the urine was collected in or out of competition. We show that there are factors reported in today's doping tests that significantly affect the steroid profiles. The factors with the largest influence on the steroid profile were the type of sport classification that the athlete belonged to as well as whether the urine was collected in or out of competition. There were also significant differences based on what time of day and time of year the urine sample was collected. Whether these significant changes are relevant when longitudinally monitoring athletes in the steroidal module of the ABP should be evaluated further.     

Investigations on changes in ¹³C/¹²C ratios of endogenous urinary steroids after pregnenolone administration

For the detection of possible misuse of naturally occurring anabolic androgenic steroids like testosterone (T), anti-doping laboratories use a combination of two techniques. One is molecular steroid profiling to evaluate urinary steroid concentrations and normal diagnostic ratios. The other is isotope ratio mass spectrometry (IRMS), in which the 13C/12C ratios of target analytes like T are compared to the 13C/12C ratios of endogenous reference compounds (ERCs). The 13C/12C of the most commonly used ERC, pregnanediol (5β-pregnane-3α,20α-diol, PD), can be influenced by administration of pregnenolone (3β-hydroxy-pregn-5-en-20-one, PREG). Therefore PREG administration bears the potential to circumvent IRMS testing for doping control samples. In order to investigate the influence of PREG on PD and on other urinary excreted steroids, administration studies with oral and transdermal application of PREG were carried out. The influence of PREG administration on concentrations and 13C/12C ratios of all investigated target analytes was negligible. Only PD and 5β-pregnan-3α-ol-20-one (3aP) showed significant depletion in both their glucuronidated and sulfated steroids. The results suggest that appropriate alternative ERCs are: 11β-hydroxy-androsterone/etiocholanolone, 5β-pregnane-3α,17,20α-triol, pregn-5-ene-3β,17,20α-triol and cholesterol. Due to its properties to disguise the misuse of anabolic steroids by influencing the 13C/12C ratio of PD, PREG should be considered to be added to the World Anti-Doping Agency (WADA) list of prohibited substances as a masking agent.     

Carbon isotope ratio mass spectrometry for detection of endogenous steroid use: A testing strategy

Isotope ratio mass spectrometry (IRMS) testing is performed to determine if an atypical steroid profile is due to administration of an endogenous steroid. Androsterone (Andro) and etiocholanolone (Etio), and/or the androstanediols (5α‐ and 5β‐androstane‐3α,17β‐diol) are typically analyzed by IRMS to determine the ¹³C/¹²C ratio. The ratios of these target compounds are compared to the ¹³C/¹²C ratio of an endogenous reference compound (ERC) such as 5β‐pregnane‐3α,20α‐diol (Pdiol). Concentrations of Andro and Etio are high so ¹³C/¹²C ratios can easily be measured in most urine samples. Despite the potentially improved sensitivity of the androstanediols for detecting the use of some testosterone formulations, additional processing steps are often required that increase labour costs and turnaround times. Since this can be problematic when performing large numbers of IRMS measurements, we established thresholds for Andro and Etio that can be used to determine the need for additional androstanediol testing. Using these criteria, 105 out of 2639 urine samples exceeded the Andro and/or Etio thresholds, with 52 of these samples being positive based on Andro and Etio IRMS testing alone. The remaining 53 urine samples had androstanediol IRMS testing performed and 3 samples were positive based on the androstanediol results. A similar strategy was used to establish a threshold for Pdiol to identify athletes with relatively ¹³C‐depleted values so that an alternative ERC can be used to confirm or establish a true endogenous reference value. Adoption of a similar strategy by other laboratories can significantly reduce IRMS sample processing and analysis times, thereby increasing testing capacity. Copyright © 2013 John Wiley & Sons, Ltd.     

False negative results in testosterone doping in forensic cases: Sensitivity of the urinary detection criteria T/E and T/LH

At the Swedish national forensic toxicology laboratory, a measured testosterone/epitestosterone (T/E) ratio ≥ 12 together with testosterone/luteinizing hormone (T/LH) in urine > 400 nmol/IU is considered as a proof of exogenous testosterone administration. However, according to the rules of the World Anti-Doping Agency (WADA), samples with T/E ratio > 4 are considered suspicious and shall be further analysed by gas chromatography–combustion–isotope ratio mass spectrometry (GC-C-IRMS) to confirm the origin of testosterone and its metabolites. The aim of this study was to investigate the possibility of false negative results and to estimate the frequency of negative results using the current criteria for detection of abuse of testosterone in forensic investigations. Urine and serum samples were collected by the police at suspected infringement of the doping law in Sweden. Fifty-eight male subjects were included in the study. Urinary testosterone was determined by gas chromatography–mass spectrometry (GC–MS), serum testosterone and LH—by immunoassay. The origin of testosterone and its metabolites was confirmed by means of GC-C-IRMS. Twenty-six of the 57 analysed subjects tested positive for exogenous testosterone using the criteria T/E ≥ 12 combined with T/LH > 400 nmol/IU. The IRMS analyses confirmed 47 positives; thus, 21 were considered false negatives. Negative predictive value was 32% (95% confidence interval [CI]: 16%–50%) and sensitivity 55%. No false positive subjects were found. The number of false negative cases using the current criteria for the detection of testosterone abuse and hence the low sensitivity indicates a need to discuss introduction of new strategies in forensic doping investigations.     

13C/12C isotope ratio MS analysis of testosterone, in chemicals and pharmaceutical preparations

The 13C/12C ratio can be used to detect testosterone misuse in sport because (semi)-synthetic testosterone is supposed to have a 13C abundance different from that of endogenous natural human testosterone. In this study, gas chromatography/combustion isotope ratio mass spectrometry (GC/C/IRMS) analysis for the measurement of the delta 13C/1000 value of testosterone from esterified forms of 13 pharmaceutical preparations, six reagent grade chemicals and three bulk materials (raw materials used in pharmaceutical proarations) obtained world-wide was investigated after applying a strong acidic solvolytic procedure. Mean delta 13C/1000 values of non esterified (free) testosterone from chemicals and bulk materials of several testosterone esters were in the range: -25.91/-32.82/1000 while the value obtained for a (semi)-synthetic, reagent grade, free testosterone was -27.36/1000. The delta 13C/1000 results obtained for testosterone from the pharmaceuticals investigated containing testosterone esters were quite homogeneous (mean and S.D. of delta 13C/1000 values of free testosterone: 27.43 +/- 0.76/1000), being the range between -26.18 and -30.04/1000. Values described above were clearly different from those reported by several authors for endogenous natural human testosterone and its main metabolites excreted into the urine in non-consumers of testosterone (delta 13C/1000 range: from -21.3 to -24.4/1000), while they were similar to those of urinary testosterone and metabolites from individuals treated with testosterone esters and testosterone precursors. This finding justifies the fact that administration of these pharmaceutical formulations led to a statistical decrease of carbon isotope ratio of urinary testosterone and its main metabolites in treated subjects.     

Studies on the in vivo metabolism of methylstenbolone and detection of novel long term metabolites for doping control analysis

The anabolic‐androgenic steroid methylstenbolone (MSTEN; 2α,17α‐dimethyl‐17β‐hydroxy‐5α‐androst‐1‐en‐3‐one) is available as a so‐called designer steroid or nutritional supplement. It is occasionally detected in doping control samples, predominantly tested and confirmed as the glucuronic acid conjugate of methylstenbolone. The absence of other meaningful metabolites reported as target analytes for sports drug testing purposes can be explained by the advertised metabolic stability of methylstenbolone. In 2013, a first investigation into the human metabolism of methylstenbolone was published, and two hydroxylated metabolites were identified as potential targets for initial testing procedures in doping controls. These metabolites were not observed in recent doping control samples that yielded adverse analytical findings for methylstenbolone, and in the light of additional data originating from a recent publication on the in vivo metabolism of methylstenbolone in the horse, revisiting the metabolic reactions in humans appeared warranted. Therefore, deuterated methylstenbolone together with hydrogen isotope ratio mass spectrometry (IRMS) in combination with high accuracy/high resolution mass spectrometry were employed. After oral administration of a single dose of 10 mg of doubly labeled methylstenbolone, urine samples were collected for 29 days. Up to 40 different deuterated methylstenbolone metabolites were detected in post‐administration samples, predominantly as glucuronic acid conjugates, and all were investigated regarding their potential to prolong the detection window for doping controls. Besides methylstenbolone excreted glucuronidated, three additional metabolites were still detectable at the end of the study on day 29. The most promising candidates for inclusion into routine sports drug testing methods (2α,17α‐dimethyl‐5α‐androst‐1‐ene‐3β,17β‐diol and 2α,17α‐dimethyl‐5α‐androst‐1‐ene‐3α,17β‐diol) were synthesized and characterized by NMR.     

Subject-based steroid profiling and the determination of novel biomarkers for DHT and DHEA misuse in sports

Doping with natural steroids can be detected by evaluating the urinary concentrations and ratios of several endogenous steroids. Since these biomarkers of steroid doping are known to present large inter-individual variations, monitoring of individual steroid profiles over time allows switching from population-based towards subject-based reference ranges for improved detection. In an Athlete Biological Passport (ABP), biomarkers data are collated throughout the athlete's sporting career and individual thresholds defined adaptively. For now, this approach has been validated on a limited number of markers of steroid doping, such as the testosterone (T) over epitestosterone (E) ratio to detect T misuse in athletes. Additional markers are required for other endogenous steroids like dihydrotestosterone (DHT) and dehydroepiandrosterone (DHEA). By combining comprehensive steroid profiles composed of 24 steroid concentrations with Bayesian inference techniques for longitudinal profiling, a selection was made for the detection of DHT and DHEA misuse. The biomarkers found were rated according to relative response, parameter stability, discriminative power, and maximal detection time. This analysis revealed DHT/E, DHT/5β-androstane-3α,17β-diol and 5α-androstane-3α,17β-diol/5β-androstane-3α,17β-diol as best biomarkers for DHT administration and DHEA/E, 16α-hydroxydehydroepiandrosterone/E, 7β-hydroxydehydroepiandrosterone/E and 5β-androstane-3α,17β-diol/5α-androstane-3α,17β-diol for DHEA. The selected biomarkers were found suitable for individual referencing. A drastic overall increase in sensitivity was obtained. The use of multiple markers as formalized in an Athlete Steroidal Passport (ASP) can provide firm evidence of doping with endogenous steroids.     

Impact of hormonal contraceptives on urinary steroid profile in relation to serum hormone changes and CYP17A1 polymorphism

To detect doping with endogenous steroids, six urinary steroids are longitudinally monitored in the athlete biological passport (ABP). These steroids include testosterone, etiocholanolone, androsterone, 5α‐androstane‐3α,17β‐diol, 5β‐androstane‐3α,17β‐diol, and the testosterone isomer epitestosterone. It is known that the intake of hormonal contraceptives may interfere with the ABP biomarkers. A previous study showed that athletes using hormonal contraceptives (HCs) display lower urinary epitestosterone concentrations than non‐using athletes. In this study, we analyzed the urinary steroid profile prior to and three months after administration of an oral HC including levonorgestrel and ethinylestradiol (n = 55). The urinary concentrations of all the ABP metabolites decreased after three months, with epitestosterone showing the largest decline (median 6.78 to 3.04 ng/mL, p?0.0001) followed by 5α‐androstane‐3α,17β‐diol (median 23.5 to 12.83 ng/mL, p?0.0001), and testosterone (median 5.32 to 3.66, p?0.0001). Epitestosterone is included in two of the five ratios in the ABP (T/E and 5αAdiol/E), and consequently these ratios increased 1.7‐fold (range 0.27 to 8.50) and 1.26‐fold (range 0.14 to 5.91), respectively. Some of these changes may mimic the changes seen after administration of endogenous steroids leading to atypical findings. Notably, even though participants used the same contraceptive treatment schedule, the HC‐mediated epitestosterone change varied to a large extent (median 0.43‐fold, range 0.06 to 6.5) and were associated with a functional T?C promoter polymorphism in CYP17A1. Moreover, the epitestosterone changes correlated with HC‐induced testosterone and gonadotropins changes in serum, indicating that urinary epitestosterone reflects the androgen load in HC‐using women.