Evaluation of markers out of the steroid profile for the screening of testosterone misuse. Part II: Intramuscular administration

Evaluation of sulfate metabolites as markers of topical testosterone administration in Caucasian and Asian populations

Sulfate metabolites of endogenous anabolic androgenic steroids (EAAS) have been shown to prolong the detection times compared with the conventional urinary markers of the steroid profile for oral and intramuscular administrations of testosterone (T). In this work, the sensitivity of sulfate EAAS markers for the detection of T gel administration has been evaluated in six Caucasian and six Asian male volunteers. Fourteen sulfate metabolites were measured in basal and post-administration samples after multiple doses of T gel (100 mg/day, three consecutive days), and the detection times based on individual thresholds for each volunteer were evaluated. Sulfate concentrations did not show adequate sensitivity, but the results of sulfate ratios were much more promising. Androsterone sulfate/testosterone sulfate (A-S/T-S), epiandrosterone sulfate/epitestosterone sulfate (epiA-S/E-S), epiA-S/T-S, and etiocholanolone sulfate/epitestosterone sulfate (Etio-S/E-S) provided the most consistent detectability for all volunteers and populations, with detection times ranging from 60 to 96 h since the first dose. Additional ratios improved detectability to up to 7 days, but only in particular volunteers. In general, sensitivity was similar to or better than the conventional testosterone/epitestosterone ratio (T/E) of the steroid profile, which further reinforces the conclusion that sulfate EAAS metabolites can be a good complement for the current steroid profile.

Detectability of oxandrolone, metandienone, clostebol and dehydrochloromethyltestosterone in urine after transdermal application

Situations of both, intentional as well as inadvertent or accidental doping, necessitate consideration in today's doping controls, especially in the light of the substantial consequences that athletes are facing in case of so-called adverse analytical findings. The aim of this study was to investigate, whether a transdermal uptake of doping substances would be possible. In addition to the period of detectability of the particular substances or respective characteristic metabolites, the possibility of deducing the route of administration by metabolite patterns was also assessed. Twelve male subjects were included in the study. Four common anabolic androgenic steroids (AAS) were dissolved in dimethylsulfoxide (DMSO) to facilitate transdermal administration on different skin regions. One half of the test persons received only oxandrolone (17α-methyl-2-oxa-4,5α-dihydrotestosterone), the other half was applied a mixture of oxandrolone, metandienone (17β-hydroxy-17-methylandrosta-1,4-dien-3-one), clostebol (4-chlorotestosterone-17β-acetate) and dehydrochloromethyltestosterone (DHCMT). Urine samples were collected 1 hour, 6 hours and one sample per day for the next 14 consecutive days. Measurements were conducted on a GC-MS/MS or LC-MS/MS system. Substance findings were obtained at least 1 day after application on nearly all skin locations. The results indicated inter-individual variability in detection windows, also varying between the different analytes and possible impact of skin location and skin thickness, respectively. Nevertheless, a rapid and rather long detectability of all substances (or respective metabolites) was given, in some cases within hours after administration and for up to 10-14 days. Hence, the transdermal application or exposure to the investigated AAS is a plausible scenario that warrants consideration in anti-doping.

Androgens, sports, and detection strategies for anabolic drug use

For decades, anabolic androgenic agents have represented the substance class most frequently observed in doping control samples. They comprise synthetic and pseudoendogenous anabolic androgenic steroids and other, mostly non-steroidal compounds with (presumed) positive effects on muscle mass and function. While exogenous substances can easily be detected by gas/liquid chromatography and mass spectrometry, significantly more complex methodologies including the longitudinal monitoring of individual urinary steroid concentrations/ratios and isotope ratio mass spectrometry are required to provide evidence for the exogenous administration of endogenous compounds. This narrative review summarizes the efforts made within the last 5 years to further improve the detection of anabolic agents in doping control samples. Different approaches such as the identification of novel metabolites and biomarkers, the acquisition of complementary mass spectrometric data, and the development of new analytical strategies were employed to increase method sensitivity and retrospectivity while simultaneously reducing method complexity to facilitate a higher and faster sample throughput.

In silico, in vitro, and in vivo human metabolism of acetazolamide, a carbonic anhydrase inhibitor and common "diuretic and masking agent" in doping

Acetazolamide (ACZ) is a carbonic anhydrase inhibitor prescribed for the treatment of various pathologies. It is also used in doping and is prohibited in and out of sportive competitions. ACZ was reported not to undergo metabolization. However, the detection of ACZ metabolites may be critical for documenting ACZ use. We aimed to further investigate ACZ metabolic fate in humans. ACZ putative metabolites were generated in silico to assist in metabolite identification. ACZ was incubated with primary human hepatocytes to identify in vitro metabolites (10 µmol/l ACZ and 10⁶ cells/ml), and urine and plasma samples from patients receiving a single 5.0 mg/kg BW PO ACZ dose were analyzed to confirm the results in vivo. Analyses were performed with reversed-phase liquid chromatography and hydrophilic interaction chromatography coupled with high-resolution tandem mass spectrometry (RPLC-HRMS/MS and HILIC-HRMS/MS, respectively). Data were screened with a software-assisted targeted/untargeted workflow. ACZ was quantified in urine samples with creatinine normalization. We identified two metabolites in hepatocyte incubations and three additional metabolites in urine and plasma. Major transformations included cysteine conjugation, glucuronidation, and N-acetylation. All metabolites were detected in plasma, 1.5 h after intake. Major metabolites were detected in urine from 0.25 to 24 h (last collection) after intake. As opposed to the literature, ACZ does undergo metabolization in humans. We propose ACZ, ACZ-Cys, and N-acetyl-ACZ in urine, and ACZ and N-acetyl-ACZ in plasma as specific biomarkers of ACZ intake in doping.

Nail Melatonin Content: A Suitable Non-Invasive Marker of Melatonin Production

Melatonin plays multiple physiological roles in the human body. Evaluation of melatonin production by the determination of urinary 6-sulfatoxymelatonin in 24-h samples has important drawbacks which hinder the successful evaluation of melatonin production in large cohorts. Here, we evaluated the potential of nail analysis for estimating melatonin production. Firstly, mass spectrometry methodology for the determination of melatonin in nails was optimized and successfully validated. The method was found to be linear in the range 6.5-830 fg/mg with intraday and interday accuracy in the range 100-104 %, precision below 15 % and a LOD of 3.5 fg/mg. Secondly, nail melatonin concentrations from 84 volunteers (age 5-96) were determined. The expected correlation between melatonin and age was obtained (correlation coefficient -0.615; p < 0.001). Additionally, we showed that fingernails are preferable to toenails to determine nail melatonin content. Finally, fingernails collected for 180 days after melatonin administration (two volunteers, 1.9 mg/night during 5 days) were analyzed. Nail melatonin concentrations immediately rose after administration and went back to pre-administration values after ≈100 days in both volunteers. Our results suggest that melatonin determination in nails is a suitable non-invasive tool for the estimation of global melatonin production. Due to the easy collection and storage of nails, the long-term information obtained and the multiple functions of melatonin, nail melatonin content might complement dim light melatonin onset, which is commonly measured from plasma/saliva samples, paving the way for melatonin research.

Evaluation of sulfate metabolites as markers of intramuscular testosterone administration in Caucasian and Asian populations

The introduction of alternative markers to the steroid profile can be an effective approach to improving the screening capabilities for the detection of testosterone (T) misuse. In this work, endogenous steroid sulfates were evaluated as potential markers to detect intramuscular (IM) T administration. Fourteen sulfate metabolites were quantified using mixed-mode solid-phase extraction and analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine samples after a single IM injection (100 mg) of T cypionate to six Caucasian and six Asian healthy male volunteers were analyzed. Principal component analysis (PCA) was used to characterize the sample cohort and to obtain the most useful markers for discrimination between pre- and post-administration samples. For Caucasian volunteers, a separation between pre- and post-administration samples was observed in PCA, whereas for Asian volunteers no separation was obtained. Seventeen ratios between sulfate metabolites were selected and further considered. Detection times (DTs) of each marker were evaluated using individual thresholds for each volunteer. The best results were obtained using ratios involving T and epitestosterone (E) sulfates in the denominator. The best marker was the ratio androsterone sulfate/testosterone sulfate (A-S/T-S) which prolonged the DT 1.2-2.1 times in respect to those obtained using T/E ratio in all Caucasian volunteers and 1.3-1.5 times in two Asian volunteers. Other ratios between A-S or etiocholanolone sulfate and E-S, and sulfates of etiocholanolone, dehydroandrosterone or epiandrosterone, and T-S were also found adequate. These ratios improve the DT after IM T administration and their incorporation to complement the current steroid profile is recommended.

Sulfate metabolites improve retrospectivity after oral testosterone administration

The detection of testosterone (T) misuse is performed using the steroid profile that includes concentrations of T and related metabolites excreted free and glucuronoconjugated, and the ratios between them. In this work, the usefulness of 14 endogenous steroid sulfates to improve the detection capabilities of oral T administration has been evaluated. Quantitation of the sulfate metabolites was performed using solid-phase extraction and analysis by liquid chromatography-tandem mass spectrometry. Urine samples were collected up to 144 hours after a single oral dose of T undecanoate (120 mg) to five Caucasian male volunteers. Detection times (DTs) of each marker were estimated using reference limits based on a population study and also monitoring the individual threshold for each volunteer. High inter-individual variability was observed for sulfate metabolites and, therefore, better DTs were obtained using individual thresholds. Using individual threshold limits, epiandrosterone sulfate (epiA-S) improved the DT with respect to testosterone/epitestosterone (T/E) ratio in all volunteers. Androsterone, etiocholanolone, and two androstanediol sulfates also improved DTs for some volunteers. Principal component analysis was used to characterize the sample cohort, obtaining 13 ratios useful for discrimination. These ratios as well as the ratio epiA-S/dehydroepiandrosterone sulfate were further examined. The most promising results were obtained using ratios between sulfates of epiA, androsterone, or androstanediol 1 and E, and also sulfates of epiA or androstanediol 1, and dehydroandrosterone. These selected ratios prolonged the DT of oral T administration up to 144 hours, which corresponded to a significantly higher retrospectivity compared to those obtained using concentrations or the conventional T/E ratio.