Serum and urinary markers of exogenous testosterone administration

In an attempt to find optimal markers of exogenous testosterone (T) administration in male athletes, a number of compounds were measured in 11 healthy men before and after 3, 6 and 9 months of weekly administration of 250 mg i.m. T enanthate and in age-matched untreated controls. The following variables were measured in serum: T, 17 alpha-hydroxyprogesterone (17-OHP), sex hormone-binding globulin (SHBG), estradiol-17 beta, estrone (free + conjugated) and luteinizing hormone (LH). The following variables were measured in urine: T glucuronide (urinary T), epitestosterone glucuronide (urinary epiT), estrone (free + conjugated) and LH. Serum T, serum T/17-OHP ratio, serum T/LH ratio, serum T/SHBG ratio, serum and urinary estrogens, urinary T/creatinine-, T/epiT- and T/LH ratios increased whereas serum 17-OHP, SHBG and LH and urinary epiT/creatinine- and LH/creatinine-ratios decreased significantly during treatment. Levels above the upper reference limit were found in all subjects at 3, 6 and 9 months for serum T/17-OHP and serum and urinary T/LH ratios and at 6 months for the urinary T/epiT ratio. Levels below the lower reference limit were found in all subjects at 3, 6 and 9 months for serum LH and the urinary LH/creatinine ratio, at 3 months for the urinary epiT/creatinine ratio and at 9 months for serum 17-OHP. No other variable showed abnormal values in all subjects at the same occasion. Despite significant changes during treatment, steroid concentrations as such are poor indicators of T doping. Serum and urinary LH levels, T/LH ratios and serum T/17-OHP ratios seem to be the most reliable markers of exogenous T administration in males.