Changes in blood parameters after intramuscular testosterone ester injections - Implications for anti-doping

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Testosterone treatment stimulates red blood cell production and alters iron homeostasis. Thus, we investigated whether the 'hematological module' of the Athlete Biological Passport (ABP) used by the World Anti-Doping Agency (WADA) can be used to indicate misuse of testosterone. Nineteen eugonadal men received intramuscular injections of either 250 mg Sustanon®, a blend of four testosterone esters, or placebo on Day 0 and 21 in a randomized, placebo-controlled double-blind design. Urine samples and blood samples for the assessment of steroidal and hematological biomarkers of the ABP were collected twice pre-treatment, at least 5 days apart, and on days 1, 3, 5, 10 and 14 post-injections. The steroidal profile was flagged suspicious in all Sustanon®-treated subjects, while the hematological profile was flagged suspicious in 6 out of 9 subjects. When considering both sensitivity and specificity, RET% appeared as the best marker of the hematological module for implying testosterone ester misuse. Atypical blood passport samples were used to select time points for further isotope-ratio mass spectrometry (IRMS) analysis of testosterone and its metabolites in simultaneously collected urine. The RET% and OFF-Score could, in addition to the T/E ratio, help identify suspicious samples for more targeted IRMS testing. The present results demonstrate that unexpected fluctuations in RET% can be indicative of testosterone doping if samples are collected 3-10 days after injection. From an anti-doping perspective, the hematological and steroidal modules of the ABP should complement each other when planning targeted follow-up testing and substantiating likely misuse of testosterone.

Original languageEnglish
JournalDrug Testing and Analysis
Publication statusE-pub ahead of print - 19 Apr 2020

Bibliographical note

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    Research areas

  • Faculty of Science - Doping in sports, Testosterone, Athlete biological passport, Haematological profile, Steroid profile

ID: 240984590