Urinary concentrations of ethyl glucuronide and ethyl sulfate as thresholds to determine potential ethanol-induced alteration of steroid profiles

Influence of ethanol consumption and food intake on serum concentrations of endogenous steroids

Steroid biosynthesis and biotransformation are based on a cascade of enzymatic processes being highly sensitive to various external influences. Amongst those, ethanol was shown to affect testosterone metabolism. For doping analyses, athlete steroid profiles comprise seven urinary steroid metabolites, of which relevant ratios are significantly increased following ethanol consumption. This effect is presumably based on the lack of hepatic NAD+-coenzyme as a consequence of ethanol oxidation. Only recently, testosterone (T) and androstenedione (A4) blood profiles have been introduced as additional approach for doping control. However, a potential influence of ethanol intake on testosterone biosynthesis and thus on blood steroid profiles has not been investigated so far. Therefore, steroid concentrations from 10 males and 10 females receiving an ethanol infusion up to a breath alcohol concentration of 0.5 mg/L which was hold as a plateau for two hours were conducted. Blood samples were drawn every 15 min for steroid quantification. An ethanol-dependent T/A4 increase up to 385% resulting from A4 suppression was observed in 14 volunteers. In addition, we observed sporadic A4 increases coinciding with cortisol and ACTH pulses pointing to a meal-induced adrenal stimulation. While testosterone levels in males showed diurnal variation solely, testosterone levels in some females were found to be susceptible to ethanol- and ACTH-dependent perturbations, which is thought to be due to its predominant adrenal synthesis in females. In conclusion, the results of the present study emphasize the importance of blood sampling at a sufficient time interval from food and ethanol intake. This is of interest if T and A4 are used for diagnostics in doping control.

Agreement of steroid profiles in Athlete Biological Passport residues and corresponding serum samples

The steroid module of the Athlete Biological Passport (ABP) is based on the analysis of six endogenous steroids in urine samples and a Bayesian statistical approach. However, the urinary steroid concentrations may be affected by confounders like microbial degradation, possible co-administration of diuretics as masking agents, insufficient conjugate hydrolysis or UGT2B17 gene polymorphisms affecting glucuronidation. Therefore, it can be helpful to use other matrices (ABP blood and serum samples) to quantify steroids and thereby support noticeable deviations in the Athlete Biological Passport, for example, abnormally increased urinary testosterone/epitestosterone (T/E) ratios. Aim of the study was to investigate the feasibility to re-use plasma obtained from athlete ABP blood samples for measuring a steroid profile. Therefore, testosterone, androstenedione, cortisol and cortisone were quantified in 36 intra-individual matching ABP blood and serum samples. The steroid levels measured in both matrices showed a high agreement indicating a good stability uninfluenced by storage temperature and duration. Our results pointed out the possibility to expand the athlete ABP blood analysis for steroid profiling.

Sports drug testing and the athletes' exposome

Similar to the general population, elite athletes are exposed to a complex set of environmental factors including chemicals and radiation and also biological and physical stressors, which constitute an exposome that is, unlike for the general population, subjected to specific scrutiny for athletes due to applicable antidoping regulations and associated (frequent) routine doping controls. Hence, investigations into the athlete's exposome and how to distinguish between deliberate drug use and different contamination scenarios has become a central topic of antidoping research, as a delicate balance is to be managed between the vital and continually evolving developments of sensitive analytical techniques on the one hand, and the risk of the athletes' exposome potentially causing adverse analytical findings on the other.

Current Insights into the Steroidal Module of the Athlete Biological Passport

For decades, the class of anabolic androgenic steroids has represented the most frequently detected doping agents in athletes' urine samples. Roughly 50% of all adverse analytical findings per year can be attributed to anabolic androgenic steroids, of which about 2/3 are synthetic exogenous steroids, where a qualitative analytical approach is sufficient for routine doping controls. For the remaining 1/3 of findings, caused by endogenous steroid-derived analytical test results, a more sophisticated quantitative approach is required, as their sheer presence in urine cannot be directly linked to an illicit administration. Here, the determination of urinary concentrations and concentration ratios proved to be a suitable tool to identify abnormal steroid profiles. Due to the large inter-individual variability of both concentrations and ratios, population-based thresholds demonstrated to be of limited practicability, leading to the introduction of the steroidal module of the Athlete Biological Passport. The passport enabled the generation of athlete-specific individual reference ranges for steroid profile parameters. Besides an increase in sensitivity, several other aspects like sample substitution or numerous confounding factors affecting the steroid profile are addressed by the Athlete Biological Passport-based approach. This narrative review provides a comprehensive overview on current prospects, supporting professionals in sports drug testing and steroid physiology.

Investigations in carbon isotope ratios of seized testosterone and boldenone preparations

In order to detect the misuse of testosterone (T) or boldenone (Bo) in doping control analysis, the confirmation of atypical findings employing the determination of carbon isotope ratios (CIR) is mandatory for issuing adverse analytical findings. Elevated concentrations of T (or elevated T/epitestosterone ratios) may result from confounding factors such as ethanol intake, and the presence of low urinary concentrations of Bo can originate from endogenous or urinary in situ production of small amounts of the steroid. As pharmaceutical preparations of Bo and T are generally depleted in ¹³ C, their CIR differ significantly from the ¹³ C-enriched endogenous steroids. Some rare cases have been reported on pharmaceutical preparations showing ¹³ C-enriched isotope ratios that complicate the current application of CIR in sports drug testing. Therefore, the CIR of a subset of n = 157 T preparations and n = 39 Bo preparations seized in Switzerland and Germany between 2013 and 2018 was analyzed in order to estimate the possible impact of steroid preparations showing ¹³ C-enriched isotope ratios on the current approach to detect their misuse. All investigated Bo preparations showed CIR in the expected range between - 26.7 and -30.3‰. Within the T samples, 95% showed the expected values below -26‰ while six samples fall between -25 and -26‰ and one sample was indistinguishable from endogenously produced T with a CIR of -23.3‰.

An in vitro assay approach to investigate the potential impact of different doping agents on the steroid profile

The steroid profile, that is, the urinary concentrations and concentration ratios of selected steroids, is used in sports drug testing to detect the misuse of endogenous steroids such as testosterone. Since several years, not only population-based thresholds are applied but also the steroid profile is monitored via the Athlete Biological Passport whereby the individual reference ranges derived from multiple test results of the same athlete are compared to population-based thresholds. In order to maintain a high probative force of the passport, samples collected or analyzed under suboptimal conditions should not be included in the longitudinal review. This applies to biologically affected or degraded samples and to samples excluded owing to the presence of other substances potentially (or evidently) altering the steroid profile. Nineteen different doping agents comprising anabolic steroids, selective androgen receptor modulators, selective estrogen receptor modulators, ibutamoren, and tibolone were investigated for their effect on the steroid profile using an androgen receptor activation test, an androgen receptor binding assay, an aromatase assay, and a steroidogenesis assay. The in vitro tests were coupled with well-established liquid chromatography/mass spectrometry-based analytical approaches and for a subset of steroidal analytes by gas chromatography/mass spectrometry. The variety of tests employed should produce a comprehensive data set to better understand how a compound under investigation may impact the steroid profile. Although our data set may allow an estimate of whether or not a substance will have an impact on the overall steroid metabolism, predicting which parameter in particular may be influenced remains difficult.

Urinary steroid profile in relation to the menstrual cycle

The interpretation of the steroidal module of the Athlete Biological Passport (ABP) in female athletes is complex due to the large variation of the endogenous urinary steroids. The menstrual cycle seems to be one of the largest confounders of the steroid profile. The duration of the different phases in the menstrual cycle differs between women and is difficult to predict only by counting days after menstruation. Here, we have determined the follicle, ovulation, and luteal phases, by assessing the menstrual hormones in serum samples collected from 17 healthy women with regular menses. Urine samples were collected three times per week during two consecutive cycles to measure the urinary steroid concentrations used in the ABP. The metabolite that was mostly affected by the menstrual phases was epitestosterone (E), where the median concentration was 133% higher in the ovulation phase compared to the follicle phase (p < 0.0001). The women with a large coefficient of variation (CV) in their first cycle also had a large CV in their second cycle and vice versa. The inter-individual difference was extensive with a range of 11%-230% difference between the lowest and the highest T/E ratio during a cycle. In conclusion, E and ratios with E as denominator are problematic biomarkers for doping in female athletes. The timing of the sample collection in the menstrual cycle will have a large influence on the steroid profile. The results of this study highlight the need to find additional biomarkers for T doping in females.

Development of a multi-functional concurrent assay using weak cation-exchange solid-phase extraction (WCX-SPE) and reconstitution with a diluted sample aliquot for anti-doping analysis

RATIONALE

In addition to the development of adequate screening methods for multiple compounds, the World Anti-Doping Agency (WADA) requires anti-doping laboratories to analyze prohibited substances and their metabolites from various classes. This task presents a difficult challenge for all agencies and interests involved in the field of doping control.

METHODS

A screening method is reported in which hybrid sample preparation was performed using a combination of weak cation-exchange solid-phase extraction (WCX-SPE) and the 'Dilute and Shoot' strategy in order to take advantage of both the methodologies. Target substances were extracted using a WCX cartridge and reconstituted with a diluted sample aliquot that included 20% of an untreated urine sample. The target substances were further analyzed by high-performance liquid chromatography/triple quadrupole mass spectrometry (LC/MS).

RESULTS

The SPE procedure was optimized using a cartridge-washing step, elution conditions, and elution volume. The cartridge-washing step, which was performed using 10% methanol, improved the overall recovery of target substances. Since the recovery was observed to vary according to the pH of the eluting solution, we applied an elution step using both an acid and a basic organic solvent to achieve complementary recovery. Reconstitution of the diluted aliquot sample was performed to recover the polar substances.

CONCLUSIONS

The method was validated and applied to real samples in accordance with the external quality assessment scheme of WADA and to the previously reported samples that had provided positive test results. This novel method using hybrid sample preparation and LC/MS could be useful to screen multiple classes of the 264 targeted substances in anti-doping analysis.

The influence of small doses of ethanol on the urinary testosterone to epitestosterone ratio in men and women

Endogenous steroid use can increase urinary testosterone/epitestosterone (T/E) values. In addition, ethanol in amounts >0.5 g per kg of body weight (g/kg) can also increase T/E values. However, the effect of smaller doses of ethanol on T/E values is unknown. The influence of 0.2 and 0.4 g/kg of ethanol on baseline T/E values in 20 men and 20 women with low and high baseline T/E values was investigated and correlated with ethyl glucuronide (EtG) and ethyl sulfate (EtS) concentrations. T/E values for 7 of the women were excluded from the study because of undetectable T concentrations or for other reasons. One man and 1 woman with a high T/E baseline value had a significant increase in their T/E value after ingestion of 0.2 g/kg of ethanol. One man and 2 women with a high T/E baseline, and 1 woman with a low T/E baseline had significantly increased T/E values after ingestion of 0.4 g/kg of ethanol. There was wide variability in peak EtG concentrations and a lack of correlation between ethanol dose and EtG concentrations. Interestingly, 1 man and 2 women with increased T/E values following ethanol ingestion had EtG concentrations below the World Anti-Doping Agency (WADA) cut-off of 5000 ng/mL. These findings demonstrate that small amounts of ethanol can elevate T/E values, with women being more susceptible. In addition, consideration should be given to the lowering of the WADA EtG cut-off to detect samples with elevated T/E values from ingestion of low doses of ethanol.

Quantitation of Ethyl Glucuronide and Ethyl Sulfate in Urine Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Ethyl glucuronide and ethyl sulfate are minor conjugated metabolites of ethanol that can be detected in urine for several days after last ingestion of ethanol. The monitoring of ethanol use has both clinical and forensic applications and a longer detection window afforded by monitoring these metabolites is obvious. LC-MS/MS is used to analyze diluted urine with deuterated analogs of each analyte as internal standards to ensure accurate quantitation and control for any potential matrix effects. High aqueous HPLC is used to chromatograph the metabolites. Negative ion electrospray is used to introduce the metabolites into the mass spectrometer. Selected reaction monitoring of two product ions for each analyte allows for the calculation of ion ratios which ensures correct identification of each metabolite, while a matrix-matched calibration curve is used for quantitation.

"Dilute-and-inject" multi-target screening assay for highly polar doping agents using hydrophilic interaction liquid chromatography high resolution/high accuracy mass spectrometry for sports drug testing

In the field of LC-MS, reversed phase liquid chromatography is the predominant method of choice for the separation of prohibited substances from various classes in sports drug testing. However, highly polar and charged compounds still represent a challenging task in liquid chromatography due to their difficult chromatographic behavior using reversed phase materials. A very promising approach for the separation of hydrophilic compounds is hydrophilic interaction liquid chromatography (HILIC). Despite its great potential and versatile advantages for the separation of highly polar compounds, HILIC is up to now not very common in doping analysis, although most manufacturers offer a variety of HILIC columns in their portfolio. In this study, a novel multi-target approach based on HILIC high resolution/high accuracy mass spectrometry is presented to screen for various polar stimulants, stimulant sulfo-conjugates, glycerol, AICAR, ethyl glucuronide, morphine-3-glucuronide, and myo-inositol trispyrophosphate after direct injection of diluted urine specimens. The usage of an effective online sample cleanup and a zwitterionic HILIC analytical column in combination with a new generation Hybrid Quadrupol-Orbitrap® mass spectrometer enabled the detection of highly polar analytes without any time-consuming hydrolysis or further purification steps, far below the required detection limits. The methodology was fully validated for qualitative and quantitative (AICAR, glycerol) purposes considering the parameters specificity; robustness (rRT < 2.0%); linearity (R > 0.99); intra- and inter-day precision at low, medium, and high concentration levels (CV < 20%); limit of detection (stimulants and stimulant sulfo-conjugates < 10 ng/mL; norfenefrine; octopamine < 30 ng/mL; AICAR < 10 ng/mL; glycerol 100 μg/mL; ETG < 100 ng/mL); accuracy (AICAR 103.8-105.5%, glycerol 85.1-98.3% at three concentration levels) and ion suppression/enhancement effects.

Confounding factors and genetic polymorphism in the evaluation of individual steroid profiling

In the fight against doping, steroid profiling is a powerful tool to detect drug misuse with endogenous anabolic androgenic steroids. To establish sensitive and reliable models, the factors influencing profiling should be recognised. We performed an extensive literature review of the multiple factors that could influence the quantitative levels and ratios of endogenous steroids in urine matrix. For a comprehensive and scientific evaluation of the urinary steroid profile, it is necessary to define the target analytes as well as testosterone metabolism. The two main confounding factors, that is, endogenous and exogenous factors, are detailed to show the complex process of quantifying the steroid profile within WADA-accredited laboratories. Technical aspects are also discussed as they could have a significant impact on the steroid profile, and thus the steroid module of the athlete biological passport (ABP). The different factors impacting the major components of the steroid profile must be understood to ensure scientifically sound interpretation through the Bayesian model of the ABP. Not only should the statistical data be considered but also the experts in the field must be consulted for successful implementation of the steroidal module.