Urinary and serum hormones profiles after testosterone enanthate administration in male hypogonadism: concerns on the detection of doping with testosterone in treated hypogonadal athletes.

Objective: To describe serum and urinary hormones, androgens metabolites and testosterone/epitestosterone ratio profiles after testosterone administration in male hypogonadal volunteers, and to evaluate their possible usefulness in detecting doping with testosterone in treated hypogonadal athletes. Design: Controlled open label design vs placebo; pharmacokinetic study. Participants: Ten male volunteers affected by severe hypogonadism (serum testosterone <2.31 ng/ml). Interventions and main outcome measures: Serum and urinary parameters were evaluated, by radioimmunoassay and gas chromatography-mass spectrometry, before and at different time points for 7/3 weeks after a single administration of testosterone enanthate (250 mg) or placebo, respectively. Results: As partially known, testosterone administration increased, with great individual variability, urinary concentrations of glucuronide testosterone, androsterone, etiocholanolone, 5α-androstane-3α,17β-diol, 5β-androstane-3α,17β-diol, testosterone/epitestosterone and testosterone/LH ratios; and decreased epitestosterone and 5α-androstane-3β,17β-diol/5β-an-drostane-3α,17β-diol ratio. Serum testosterone and dihydrotestosterone increased in all volunteers, and concentrations higher than the upper reference limits were observed in many volunteers until 2 weeks after testosterone administration. Conclusion: Whereas the observed prolonged hyperandrogenism partially limited data interpretation, the reported characteristics of variation of urinary parameters might be used to suspect testosterone misuse in hypogonadal athletes treated with testosterone enanthate. In this sense, while the actual threshold for testosterone/epitestosterone ratio was confirmed to be of reduced usefulness, we suggest a contemporary evaluation of whole urinary androgen metabolites profile and serum androgens, at specific time points after testosterone enanthate administration. Moreover, an adequate tailoring of treatment, to avoid transitory hyperandrogenism, is highly advisable. Further studies on strategies for detecting doping with testosterone in hypogonadal athletes are warranted.