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Polet M, Van Eenoo P, Brooker L, Edey C, Agon V, Grainger J, Payne G, Goebel C. Prevalence of nandrolone preparations with endogenous carbon isotope ratios in Australia. Drug Test Anal 2024. [PMID: 38342098 DOI: 10.1002/dta.3654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/13/2024]
Abstract
Nandrolone and its prohormones, including 19-norandrost-4-ene-3,17-dione and 19-norandrost-4-ene-3β,17β-diol, are anabolic steroids forbidden at all times in sports according to the World Anti-Doping Code Prohibited List and its metabolite 19-norandrosterone (19NA) is the preferred urinary target compound to identify their abuse. In recent years, an increasing number of 19NA isotope ratio mass spectrometry (IRMS) cases have arisen that, based on the initial testing procedure, were likely to result in an adverse analytical finding but were concluded negative after IRMS analysis. The current study was therefore set up to gain a better insight on the prevalence of nandrolone preparations with endogenous carbon isotope ratio values in Australia. Suitable workplace (non-athlete) urine samples that had previously been reported positive for 19NA were identified and analysed on IRMS. A total of 82% of the samples that were analysed were reported with enriched carbon isotope ratios of 19NA (i.e., 19NA greater than -26‰). This indicates that there is a high prevalence of nandrolone-containing anabolic androgenic steroid preparations in Australia that have 'endogenous' carbon isotope ratios which reduces the ability to identify exogenous nandrolone.
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Affiliation(s)
- Michael Polet
- Department of Diagnostic Sciences, Doping Control Laboratory, Ghent University, Ghent, Belgium
| | - Peter Van Eenoo
- Department of Diagnostic Sciences, Doping Control Laboratory, Ghent University, Ghent, Belgium
| | - Lance Brooker
- Australian Sports Drug Testing Laboratory, National Measurement Institute, Sydney, New South Wales, Australia
| | - Claire Edey
- Australian Sports Drug Testing Laboratory, National Measurement Institute, Sydney, New South Wales, Australia
| | - Vanessa Agon
- Australian Sports Drug Testing Laboratory, National Measurement Institute, Sydney, New South Wales, Australia
| | - Janelle Grainger
- Australian Sports Drug Testing Laboratory, National Measurement Institute, Sydney, New South Wales, Australia
| | - Gemma Payne
- Sport Integrity Australia, Fyshwick, Australian Capital Territory, Australia
| | - Catrin Goebel
- Australian Sports Drug Testing Laboratory, National Measurement Institute, Sydney, New South Wales, Australia
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2
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Piper T, Krombholz S, Thevis M. Carbon isotope ratios of phenethylamine and its urinary metabolite phenylacetylglutamine. Drug Test Anal 2023. [PMID: 38048815 DOI: 10.1002/dta.3616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 12/06/2023]
Abstract
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.
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Affiliation(s)
- Thomas Piper
- Center for Preventive Doping Research, Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Sophia Krombholz
- Center for Preventive Doping Research, Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Mario Thevis
- Center for Preventive Doping Research, Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
- European Monitoring Center for Emerging Doping Agents (EuMoCEDA), Cologne, Germany
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3
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Nair VS, Howa JD, Morrison MS, Beggs L, Campbell T, Fedoruk M, Ahrens B, Eichner D. δ 13 C values of urinary 19-norandrosterone in antidoping samples and potential for adverse findings from boar offal consumption. Drug Test Anal 2023; 15:1356-1360. [PMID: 36929692 DOI: 10.1002/dta.3470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 03/18/2023]
Abstract
19-Norandrosterone (19NA) is the preferred urinary target compound to identify doping with nandrolone or related 19-norsteroids. At concentrations between 2.5 and 15 ng/mL, isotope ratio mass spectrometry (IRMS) is required to establish exogenous origin of urinary 19NA. An absolute difference of 3‰ between urinary 19NA and an endogenous reference compound (ERC) constitutes a finding for exogenous origin of 19NA. Over the last 3 years, 77 samples containing urinary 19NA between 2.5 and 15 ng/mL were analyzed at our laboratory. The measured δ13 C values for 19NA ranged from -29.5‰ to -16.8‰. In comparison, the δ13 C values for the corresponding urinary ERCs ranged from -22.4‰ to -16.2‰. Due to the considerable overlap in values between the target compound and the natural range of urinary ERCs, it can be challenging to distinguish between endogenous and exogenous origins of urinary 19NA. In addition, it is well known that consumption of offal from non-castrated pigs can produce 19NA in urine. To determine whether this could cause a positive IRMS finding under the current IRMS positivity criteria, meat from non-castrated boars fed a mixture of corn and soy was consumed by 13 volunteers. Two volunteers produced 19NA findings above 2.5 ng/mL, and the measured isotope values, while inconsistent with documented 19-norsteroid preparations, did meet IRMS positivity criteria. However, these increases in 19NA urinary concentrations were short-lived due to rapid elimination. Timely follow-up collections may help support a claim for dietary exposure when low urinary concentrations of 19NA with pseudo-endogenous isotope values are observed.
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Affiliation(s)
- Vinod S Nair
- Sports Medicine Research and Testing Laboratory, South Jordan, Utah, USA
| | - John D Howa
- Sports Medicine Research and Testing Laboratory, South Jordan, Utah, USA
| | - Matthew S Morrison
- Sports Medicine Research and Testing Laboratory, South Jordan, Utah, USA
| | - Lacey Beggs
- Sports Medicine Research and Testing Laboratory, South Jordan, Utah, USA
| | - Thane Campbell
- Sports Medicine Research and Testing Laboratory, South Jordan, Utah, USA
| | - Matthew Fedoruk
- United States Anti-Doping Agency, Colorado Springs, Colorado, USA
| | - Brian Ahrens
- UCLA Olympic Analytical Laboratory, Los Angeles, California, USA
| | - Daniel Eichner
- Sports Medicine Research and Testing Laboratory, South Jordan, Utah, USA
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4
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Merrick JP, Liu FH, Lewin M, Iavetz R. Bias estimation in the certification of steroid reference materials for carbon isotope delta measurements via elemental analyser and gas chromatography-combustion-isotope ratio mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9502. [PMID: 36914244 DOI: 10.1002/rcm.9502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 03/03/2023] [Accepted: 03/04/2023] [Indexed: 06/18/2023]
Abstract
RATIONALE Two new certified reference materials (CRMs) have been prepared providing three steroids certified for stable carbon isotope delta values, δ(13 C) ‰. These materials have been designed to assist anti-doping laboratories in validating their calibration method or to be employed as calibrant for stable carbon isotope measurements of Boldenone, Boldenone Metabolite 1 and Formestane. These CRMs will allow for accurate and traceable analysis in compliance with World Anti-Doping Agency (WADA) Technical Document TD2021IRMS. METHODS Certification was performed using an elemental analyser-isotope ratio mass spectrometry (EA-IRMS) primary reference method on the bulk carbon isotope ratios of nominally pure steroid starting materials. EA-IRMS analyses were carried out on a Flash EA Isolink CN coupled via a Conflo IV to a Delta V plus mass spectrometer. Confirmation analysis was performed by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) using a Trace 1310 GC coupled to a Delta V plus mass spectrometer via GC Isolink II. RESULTS Based on the EA-IRMS analysis, the materials were certified with δ(13 C) values of -30.38‰ (Boldenone), -29.71‰ (Boldenone Metabolite 1) and 30.71‰ (Formestane). Noting that the assumption of 100% purity in the starting materials has the potential to introduce bias, this was investigated using GC-C-IRMS analysis and theoretical modelling based on purity assessment data. CONCLUSIONS Careful application of this theoretical model was shown to provide reasonable estimates of uncertainty while avoiding the introduction of errors associated with analyte-specific fractionation during GC-C-IRMS analysis.
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Affiliation(s)
- Jeffrey P Merrick
- Chemical Reference Values, National Measurement Institute, North Ryde, New South Wales, Australia
| | - Fong-Ha Liu
- Chemical Reference Values, National Measurement Institute, North Ryde, New South Wales, Australia
| | - Mark Lewin
- Chemical Reference Values, National Measurement Institute, North Ryde, New South Wales, Australia
| | - Raluca Iavetz
- Chemical Reference Values, National Measurement Institute, North Ryde, New South Wales, Australia
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Piper T, Geyer H, Haenelt N, Huelsemann F, Schaenzer W, Thevis M. Current Insights into the Steroidal Module of the Athlete Biological Passport. Int J Sports Med 2021; 42:863-878. [PMID: 34049412 PMCID: PMC8445669 DOI: 10.1055/a-1481-8683] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 04/07/2021] [Indexed: 12/25/2022]
Abstract
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.
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Affiliation(s)
- Thomas Piper
- Center for Preventive Doping Research – Institute of
Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Hans Geyer
- Center for Preventive Doping Research – Institute of
Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Nadine Haenelt
- Center for Preventive Doping Research – Institute of
Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Frank Huelsemann
- Center for Preventive Doping Research – Institute of
Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Wilhelm Schaenzer
- Center for Preventive Doping Research – Institute of
Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Mario Thevis
- Center for Preventive Doping Research – Institute of
Biochemistry, German Sport University Cologne, Cologne, Germany
- European Monitoring Center for Emerging Doping Agents (EuMoCEDA)
Cologne/Bonn Germany
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6
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Hülsemann F, Fußhöller G, Lehn C, Thevis M. Excretion of 19‐norandrosterone after consumption of boar meat. Drug Test Anal 2020; 12:1581-1586. [DOI: 10.1002/dta.2958] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/28/2020] [Accepted: 10/17/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Frank Hülsemann
- Institute of Biochemistry German Sport University Cologne Cologne Germany
| | - Gregor Fußhöller
- Institute of Biochemistry German Sport University Cologne Cologne Germany
| | - Christine Lehn
- Institute of Legal Medicine University of Munich Munich Germany
| | - Mario Thevis
- Institute of Biochemistry German Sport University Cologne Cologne Germany
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7
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Iannella L, Botrè F, Colamonici C, Curcio D, Ciccarelli C, Mazzarino M, Torre X. Carbon isotopic characterization of prednisolone and prednisone pharmaceutical formulations: Implications in antidoping analysis. Drug Test Anal 2020; 12:1587-1598. [DOI: 10.1002/dta.2876] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 01/21/2023]
Affiliation(s)
- Loredana Iannella
- Laboratorio Antidoping, Federazione Medico Sportiva Italiana Rome Italy
- Dipartimento di Chimica e Tecnologia del Farmaco “Sapienza” Università di Roma Rome Italy
| | - Francesco Botrè
- Laboratorio Antidoping, Federazione Medico Sportiva Italiana Rome Italy
- Dipartimento di Medicina Sperimentale “Sapienza” Università di Roma Rome Italy
| | | | - Davide Curcio
- Laboratorio Antidoping, Federazione Medico Sportiva Italiana Rome Italy
| | | | - Monica Mazzarino
- Laboratorio Antidoping, Federazione Medico Sportiva Italiana Rome Italy
| | - Xavier Torre
- Laboratorio Antidoping, Federazione Medico Sportiva Italiana Rome Italy
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8
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de Oliveira FA, Casilli A, Piper T, da Silva TR, da Silva CA, da Silva RVS, Dal Sasso MA, Salgueiro GRDSG, Padilha MC, Pereira HMG, Thevis M, de Aquino Neto FR. Implementation and Performance of the Gas Chromatography/Combustion/Isotope Ratio Mass Spectrometry-Based Method for the Confirmatory Analysis of Endogenous Anabolic Steroids during the Rio de Janeiro Olympic and Paralympic Games 2016. Anal Chem 2019; 91:11747-11756. [DOI: 10.1021/acs.analchem.9b02341] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fábio Azamor de Oliveira
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Alessandro Casilli
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Thomas Piper
- Center for Preventive Doping Research − Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, Cologne 50933, Germany
| | - Thais Reis da Silva
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Cristiane Abrantes da Silva
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Raquel Vieira Santana da Silva
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Marco Aurelio Dal Sasso
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Gutierri Ricardo dos Santos Gonçalves Salgueiro
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Monica Costa Padilha
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Henrique Marcelo Gualberto Pereira
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
| | - Mario Thevis
- Center for Preventive Doping Research − Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, Cologne 50933, Germany
| | - Francisco Radler de Aquino Neto
- Brazilian Doping Control Laboratory − LBCD, LADETEC, Av. Horácio Macedo, 1281 − Polo de Química − Bloco C − Cidade Universitária − Ιlha do Fundão, Federal University of Rio de Janeiro − UFRJ, Rio de Janeiro 21941-901, Brazil
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9
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Brailsford AD, Majidin WNM, Wojek N, Cowan DA, Walker C. IRMS delta values (
13
C) of nandrolone and testosterone products available in the UK: Implications for anti‐doping. Drug Test Anal 2018; 10:1722-1727. [DOI: 10.1002/dta.2530] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Alan D. Brailsford
- Drug Control Centre, King's Forensics, Department of Analytical, Environmental and Forensic SciencesKing's College London London SE1 9NH UK
| | - Wan Noor Mahirah Majidin
- Drug Control Centre, King's Forensics, Department of Analytical, Environmental and Forensic SciencesKing's College London London SE1 9NH UK
| | - Nick Wojek
- UK Anti‐Doping Fleetbank House, 2‐6 Salisbury Square London EC4Y 8AE UK
| | - David A. Cowan
- Drug Control Centre, King's Forensics, Department of Analytical, Environmental and Forensic SciencesKing's College London London SE1 9NH UK
| | - Christopher Walker
- Drug Control Centre, King's Forensics, Department of Analytical, Environmental and Forensic SciencesKing's College London London SE1 9NH UK
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10
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Hülsemann F, Gougoulidis V, Schertel T, Fusshöller G, Flenker U, Piper T, Thevis M. Case Study: Atypical
δ
13
C values of urinary norandrosterone. Drug Test Anal 2018; 10:1728-1733. [DOI: 10.1002/dta.2498] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 01/31/2023]
Affiliation(s)
- Frank Hülsemann
- German Sport University Cologne, Institute of Biochemistry Cologne Germany
| | | | - Thomas Schertel
- German Sport University Cologne, Institute of Biochemistry Cologne Germany
| | - Gregor Fusshöller
- German Sport University Cologne, Institute of Biochemistry Cologne Germany
| | - Ulrich Flenker
- German Sport University Cologne, Institute of Biochemistry Cologne Germany
| | - Thomas Piper
- Center for Preventive Doping Research – Institute of BiochemistryGerman Sport University Cologne Cologne Germany
| | - Mario Thevis
- German Sport University Cologne, Institute of Biochemistry Cologne Germany
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Strahm E, Emery C, Saugy M, Dvorak J, Saudan C. Detection of testosterone administration based on the carbon isotope ratio profiling of endogenous steroids: international reference populations of professional soccer players. Br J Sports Med 2009; 43:1041-4. [PMID: 19549614 PMCID: PMC2784500 DOI: 10.1136/bjsm.2009.058669] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2009] [Indexed: 11/10/2022]
Abstract
BACKGROUND AND OBJECTIVES The determination of the carbon isotope ratio in androgen metabolites has been previously shown to be a reliable, direct method to detect testosterone misuse in the context of antidoping testing. Here, the variability in the 13C/12C ratios in urinary steroids in a widely heterogeneous cohort of professional soccer players residing in different countries (Argentina, Italy, Japan, South Africa, Switzerland and Uganda) is examined. METHODS Carbon isotope ratios of selected androgens in urine specimens were determined using gas chromatography/combustion/isotope ratio mass spectrometry (GC-C-IRMS). RESULTS Urinary steroids in Italian and Swiss populations were found to be enriched in 13C relative to other groups, reflecting higher consumption of C3 plants in these two countries. Importantly, detection criteria based on the difference in the carbon isotope ratio of androsterone and pregnanediol for each population were found to be well below the established threshold value for positive cases. CONCLUSIONS The results obtained with the tested diet groups highlight the importance of adapting the criteria if one wishes to increase the sensitivity of exogenous testosterone detection. In addition, confirmatory tests might be rendered more efficient by combining isotope ratio mass spectrometry with refined interpretation criteria for positivity and subject-based profiling of steroids.
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Affiliation(s)
- E Strahm
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, West Switzerland, Epalinges, Switzerland
| | - C Emery
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, West Switzerland, Epalinges, Switzerland
| | - M Saugy
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, West Switzerland, Epalinges, Switzerland
| | - J Dvorak
- FIFA Medical Assessment and Research Centre, Zürich, Switzerland
| | - C Saudan
- Swiss Laboratory for Doping Analyses, University Center of Legal Medicine, West Switzerland, Epalinges, Switzerland
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