Impact of repeated oral glucocorticoid administration on the steroid profile

Code: 21D06RV

The steroid profile is used to detect administration of testosterone and other endogenous anabolic androgenic steroids. Metabolites included in the steroid profile have both gonadal and adrenal origin. Glucocorticosteroids (GC) inhibit the hypothalamic-pituitary-adrenal axis, and reduce the adrenal steroid production. For that reason, an effect on the urinary steroid profile might be expected. 

In a previous project, we evaluated the effect of single oral or intramuscular administration of GC on the steroid profile. A significant decrease in the excretion rates of steroid profile metabolites was observed after GC administration that was found to be associated with the dose. However, the ratios between metabolites evaluated in the athlete’s biological passport were not significantly altered, although all volunteers receiving the highest intramuscular dose showed a clear decrease in some of the ratios. Given the significant decrease in the excretion rates of steroid profile metabolites after a single dose and the alterations of some of the ratios, the question of what would happen after repeated administration of GC arose.

 The aim of the present project is to evaluate the effect of repeated oral doses of dexamethasone (DEX) or methylprednisolone (MP) on the steroid profile. Repeated oral doses of DEX or MP will be administered to eight healthy volunteers. The steroid profile will be measured by GC-MS/MS in urines collected before and after administration. The excretion rates of the metabolites will be calculated. In addition the adaptive module will be applied: samples collected before administration will be used to establish the reference ranges for each volunteer, and post-administration samples will be individually compared with these reference ranges.

Main findings

The steroid profile (SP) is a powerful tool to detect the misuse of endogenous anabolic androgenic steroids in sports. The SP consists of the longitudinal monitoring of concentrations of testosterone (T), its related metabolites (epitestosterone, E; androsterone, A; etiocholanolone, Etio; 5α-androstane-3α,17β-diol, 5aAdiol; and 5β-androstane-3α,17β-diol, 5bAdiol), and the ratios between them (T/E, 5aAdiol/E, A/T, A/Etio and 5aAdiol/5bAdiol). Alterations on the SP cannot only be associated with doping practices, but also with the presence of confounding factors. Glucocorticoids (GC) could be a confounding factor to the SP since they inhibit the HPA axis, and the SP metabolites have partial adrenal origin. In fact, in a study conducted by our group, GC treatments involving single-dose systemic administration produced a reduction of the excretion rates of the SP metabolites, as well as a decrease of the A/T and 5aAdiol/E ratios. However, the reduction in the SP ratios did not result in atypical profiles. Considering these results, the question regarding the potential effect of repeated GC administrations on the SP arose.

In this study, the impact of multiple oral administrations of GCs on the SP was evaluated in two studies, using two of the GCs most detected in sports drug testing: methylprednisolone (MP) and dexamethasone (DEX) (n=8 volunteers each study). In MP study, 12 mg of MP were administered per day during 3 consecutive days. In the DEX study, 2 mg of DEX were administered every 12 h for 5 consecutive days. Urine samples were collected before, during and after the GC treatments, and the SP was measured in all samples using gas chromatography-tandem mass spectrometry. The multiple dose oral administration of GCs resulted in a treatment-dependent reduction of the excretion rates of some SP metabolites (5aAdiol, A and Etio) and the SP ratios A/T and 5aAdiol/E. The T/E ratio was not significantly affected.

Overall, although the consumption of GC could result in atypical profiles for A/T and 5aAdiol/E, according to the cost/benefit assessment, GC should not be considered a confounding factor to the SP since misunderstandings in the evaluation of the SP would only take place in very specific situations and, in those cases, the analysis by GC/C/IRMS of the sample triggering the atypical profile would demonstrate the endogenous origin of the SP metabolites.