Thomas Piper’s research while affiliated with Deutsche Sporthochschule Köln and other places

The determination of serum concentrations of testosterone (T) and 4-androstenedione (A4) was implemented into the steroidal module of the Athlete Biological Passport in 2023. Monitoring T, A4, and the ratio of T/A4 in a longitudinal manner enables the detection of the misuse of low-dose T administrations especially in female athletes, whereas urinary markers of the steroid profile may not be influenced significantly. In contrast to the urinary steroid profile, knowledge on confounding factors regarding serum concentrations of T and A4 is yet comparably scarce, and corroborating exogenous sources of the target analytes by isotope ratio mass spectrometry (IRMS) is desirable. In a recent study, it was demonstrated that carbon isotope ratios (CIRs) of serum steroids can be determined if analyte concentrations permit. The therein-employed method utilized 2D-GC/IRMS, and only a limited number of potential endogenous reference compounds were available. The here-presented approach uses complementary analyte purification strategies, addressing previous limitations. A high-performance liquid chromatography cleanup was developed and fully validated for serum steroids in order to enable all doping control laboratories to potentially implement this method alongside existing protocols for urinary steroids. Besides the already-investigated endogenous steroids cholesterol, dehydroepiandrosterone sulfate, androsterone sulfate, and epiandrosterone sulfate, two additional steroids were included in the test menu, namely, pregnenolone sulfate and 5-androstene-3β,17β-diol sulfate. Serum steroid concentrations down to 25 ng/mL were found to allow robust CIR determinations, and a reference population encompassing 124 male and female athlete samples was investigated to enable the calculation of population-based thresholds for all relevant steroid combinations.

The synthetic 20‐keto‐steroid S42 ( 1 ) demonstrated selective androgen receptor modulator (SARM) properties in preclinical studies and, consequently, received growing attention also in the context of sports drug testing programs. Fundamental understanding of the behavior of S42 ( 1 ) and of relevant derivatives in gas chromatography‐electron ionization MS experiments at high resolution (GC‐EI‐HRMS) is indispensable to develop a reliable qualitative and quantitative doping control method for S42 ( 1 ) and its metabolites in body fluid matrices. We present important fundamental mechanistic data on the EI fragmentation behavior of S42 ( 1 ) and of silyl ether derivatives as well as of stable isotope‐labelled reference material.

Doping practices in sports by unscrupulous athletes have been an important societal issue for several decades. Recently, sample swapping has been raised as a potential practice performed by athletes to swap their doped samples with clean samples to evade the positive doping test. So far, the only proven method to detect such cases is by performing DNA analysis on samples. However, it is expensive and time-consuming, which goes beyond the budgetary limits of anti-doping organisations when implementing to all the samples collected during sports events. Therefore, in this paper, we propose a self attention-based convolutional neural network (SACNN) that incorporates both spatial and temporal behaviour of the longitudinal profile and generates embedding maps for solving the fraud detection problem in sports. We conduct extensive experiments on the real-world datasets. The result shows that SACNN outperforms other state-of-the-art baseline models for sequential anomaly detection. Moreover, we conduct a study with domain experts on real-world profiles using both DNA analysis and our proposed method; the result demonstrates the effectiveness of our proposed method and the impact it could bring to the society.

Adrenosterone (Androst-4-ene-3,11,17-trione, 11OXO) is forbidden in sports according to the Prohibited List of the World Anti-Doping Agency. The administration of 11OXO may be detected by monitoring the urinary concentrations of its main human metabolites 11β-hydroxy-androsterone and 11β-hydroxy-etiocholanolone. Preliminary urinary concentration and concentration ratio thresholds have been established for sports drug testing purposes, but adaptations are desirable as the suggested limits would result in numerous suspicious findings due to naturally elevated concentrations and ratios. Recently, the metabolism of 11-oxo-testosterone (KT) was investigated in the context of anti-doping research, resulting in a preliminary urinary concentration threshold and a confirmation procedure based on the determination of carbon isotope ratios (CIRs). Gas chromatography coupled to isotope ratio mass spectrometry was employed to investigate the CIRs of selected steroids. As KT is also a metabolite of 11OXO, the developed protocols for KT have been tested to elucidate their potential to detect the administration of 11OXO after a single oral dose of 100 mg. In order to further improve the analytical approach, the threshold for urinary concentrations of KT was re-investigated by employing a reference population of n = 5232 routine doping control samples. Quantification of urinary steroids was conducted by employing gas chromatography coupled to triple quadrupole mass spectrometry. Derived from these, a subset of n = 106 samples showing elevated concentrations of KT was investigated regarding their CIRs. By means of this, potentially positive samples due to the illicit administration of 11OXO or KT could be excluded, and the calculation of reference population-derived thresholds for the concentrations and CIR of KT was possible. Based on the results, the urinary concentration threshold for KT is suggested to be established at 130 ng/mL.

Phenethylamine (PEA) is a naturally occurring trace amine that acts as a modulator in the central nervous system. It is widely sold as a dietary supplement and advertised for its mood enhancing effects and should support weight loss. It is prohibited in sports and itemized as a stimulant on the Prohibited List issued by the World Anti‐Doping Agency (WADA). After oral administration of PEA, its urinary concentration is found only slightly elevated while metabolites of PEA show a significant increase. Besides 2‐(2‐hydroxyphenyl)acetamide sulfate, especially phenylacetylglutamine (PAG) was found at significantly elevated urinary concentrations after the administration. Due to large inter‐ and intra‐individual variations in urinary concentrations of all metabolites, establishing a concentration or concentration ratio‐based threshold remained complicated to unambiguously identify post‐administration samples. In accordance with the approach employed in detecting testosterone misuse, the applicability of isotope ratio mass spectrometry to differentiate between endogenously elevated concentrations and PEA administrations was investigated. A method encompassing solid‐phase extraction combined with acetylation and high‐performance liquid chromatography (HPLC)‐based clean‐up was developed and validated for PEA. The more abundant metabolite PAG was purified by a direct injection approach on the HPLC and could be analyzed without the need for derivatization. Both methods were validated considering applicable WADA regulations. A reference population encompassing n = 57 samples was investigated to establish population‐based thresholds considering the carbon isotope ratios (CIRs) found at natural abundance for PAG. The derived threshold was tested for its applicability by re‐analysis of numerous post‐administration samples encompassing single‐ and multi‐dose trials.

The possible performance‐enhancing effects and medical benefits of ecdysterone (ECDY) have been discussed several times throughout the last decades. In 2020, the World Anti‐Doping Agency include ECDY in their monitoring programme and continued this prevalence study until now. Only little is known about the human metabolism of ECDY besides the first study performed on human subjects in the field of sports drug testing that was already conducted in 2001. Aim of this study was the in‐depth investigation on human ECDY metabolism to improve its detectability and to support the decision‐making processes as to how ECDY can be implemented most effectively into sports drug testing regulations. In a first trial, one male volunteer was administered with threefold deuterated ECDY to enable the detection and potential identification of all urinary metabolites still comprising the deuterium label by employing hydrogen isotope ratio mass spectrometry and high‐resolution/high‐accuracy mass spectrometry. Samples were collected for up to 14 days, and metabolites excreted unconjugated, glucuronidated, and sulphated were investigated. The detected deuterated metabolites were confirmed in a second administration trial encompassing two male and one female volunteers. After the administration of 50 mg of unlabelled ECDY, urine samples were collected for up to 7 days. Besides the already described urinary metabolites of ECDY, more than 20 new metabolites were detected encompassing all expected metabolic conversions including side chain cleavage at C21. A large interindividual variation in the amounts of excreted metabolites was visible, and considerable differences in abundances of early‐ and late‐excretion phase metabolites were observed.

2‐(Dimethylamino)ethan‐1‐ol (Deanol) is a widely produced chemical used by both industry and consumers in a variety of applications. Meclofenoxate, a stimulant classified on the World Anti‐Doping Agency Prohibited List, metabolizes into deanol and, presumably, its main metabolite deanol‐ N ‐oxide. Hence, using liquid chromatography–tandem mass spectrometry, a quantitative detection method for deanol‐ N ‐oxide in urine was developed. Subsequently, the urinary excretion of deanol‐ N ‐oxide after oral application of 130 mg of deanol was determined in six volunteers, and urine samples of a cohort of 180 male and female athletes from different sports were analyzed. In addition, urinary deanol‐ N‐ oxide was determined in an exploratory study with one volunteer ingesting 250 mg of meclofenoxate. The developed test method allowed for limits of detection and quantification for deanol‐ N ‐oxide at 0.05 and 0.15 μg/mL, respectively. Urinary deanol‐ N ‐oxide c max levels were found between 100 and 250 μg/mL 2–5 h post‐administration of 130 mg of deanol. Similarly, urine samples collected after the administration of 250 mg of meclofenoxate exhibited c max levels of 115 μg/mL. In contrast, deanol‐ N ‐oxide urine concentrations of pre‐administration specimens and 180 routine doping control urine sample were between 0.3 and 1.3 μg/mL and below limit of quantification and 1.8 μg/mL, respectively. The study suggests that the use of deanol and meclofenoxate results in significantly elevated urinary deanol‐ N ‐oxide levels. Whether or not monitoring deanol‐ N ‐oxide in doping controls can support decision‐making processes concerning the detection of meclofenoxate use necessitates further investigations taking into consideration the elimination kinetics of 4‐chlorophenoxyacetic acid, the main metabolite of meclofenoxate, and deanol‐ N ‐oxide.

The anabolic properties of 11‐hydroxyandrostenedione (OHA4) and its physiologically active metabolites 11‐ketotestosterone (KT) and 11‐ketodihydrotestosterone (KDHT) have been discussed in several recent publications. Especially KT has become readily available via internet‐based providers. No doping control methods for the detection of KT or KDHT exist, neither on the initial testing procedure level nor as confirmatory assay. Probing for the misuse of adrenosterone, the prohormone of OHA4, has already been addressed, and the suggested marker for its misuse was mainly the urinary concentration of 11‐hydroxyandrosterone (OHA). In addition, for confirmation purposes, the carbon isotope ratios (CIR) were taken into consideration. The urinary concentration of OHA is highly variable and the endogenous dilution after exogenous administration may therefore be considerable; hence, described approaches resulted in short detection times. In this study, the human metabolism of KT was investigated in order to provide additional means for the detection of KT and its prohormone OHA4. Two volunteers (one female and one male) orally administered 20 mg of KT each, and urine samples were collected for 5 days. Urinary concentrations of KT and its metabolites were investigated, and a reference population encompassing 220 male and female athletes was investigated in order to elucidate preliminary thresholds. As confirmation procedure, an isotope ratio mass spectrometry‐based method was developed in order to determine the CIR of KT and relevant metabolites. The developed methods enabled the detection of exogenous KT for more than 20 h after a single oral administration, which is comparable to a single oral testosterone administration.