Abstract

Using a comprehensive GC/MS method the usefulness of naturally occurring minor steroids metabolites was investigated for the detection of misuse with small doses of various formulations of endogenous steroids in sports. For 24 endogenous steroids, precursors and steroid metabolites the reference ranges were established and applied upon excretion urines. It was concluded that decision limits based upon population statistics were inadequate to detect the misuse of small amounts of steroids and steroid gels. Several steroid metabolites were investigated for best detection sensitivity and maximal detection times with respect to their population thresholds. Minor steroid metabolite ratios were investigated in a longitudinal way and implemented as potential biomarkers within the context of the adaptive Bayesian model as used in the Biological Passport. Using this individual approach, detection accuracy and detection times could be further improved. According to the traditional WADA (TD2004) criteria for screening, 11% of excretion urines were identified with atypical steroid profiles of which 95% was confirmed by IRMS until 7 days after administration. Screening with the Alternative Steroid Profiling strategy led to an additional 14% more atypical steroid profiles of which 84% could be confirmed by IRMS analysis applying compound specific ∆δ13C criteria. This study proves the usefulness of minor steroid metabolites in steroid profiling as well as the relevance of direct individual monitoring of steroid profiles of athletes in the biological passport concept. Verf.-Referat