title: Evaluation of testosterone/epitestosterone ratio influential factors as determined in doping analysis.
abstract: The ratio of the concentration of testosterone glucuronide to the concentration of epitestosterone glucuronide (T/E ratio) as determined in urine is the most frequently used method to prove testosterone abuse by athletes. A T/E ratio higher than 6 has been considered as proof of abuse in the past; however, cases of naturally occurring higher T/E ratios have been described. Since the introduction of the T/E ratio in doping analysis, the parameters that may or may not influence the T/E ratio, possibly leading to false-positive results, have been debated. To achieve more insight on the influencing circumstances, an overview is given to obtain an objective view on the merits of the urinary T/E ratio. Relevant analytical aspects of the T/E ratio, potential parameters of endogenous and exogenous origins, as well as some alternative methods to determine testosterone abuse, such as the urinary testosterone/luteinizing hormone ratio, gas chromatography-combustion-isotope-ratio mass spectrometry, hair analysis, and high-performance liquid chromatography-mass spectrometry, are discussed.
authors.affiliation: Utrecht Institute of Pharmaceutical Sciences, Department of Human Toxicology, University of Utrecht, The Netherlands. D.H.vandeKerkhof@pharm.uu.nl
authors.forename: D H
authors.initials: DH
authors.lastname: van de Kerkhof
authors.forename: D
authors.initials: D
authors.lastname: de Boer
authors.forename: J H
authors.initials: JH
authors.lastname: Thijssen
authors.forename: R A
authors.initials: RA
authors.lastname: Maes
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004300:Doping in Sports; D004845:Epitestosterone / Q000652:urine*; D005069:Evaluation Studies as Topic; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006197:Hair / Q000737:chemistry; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D015813:Substance Abuse Detection / Q000379:methods*; D013739:Testosterone / Q000494:pharmacology / Q000652:urine*
chemical_list: D013739:Testosterone; D004845:Epitestosterone