Determination of the origin of urinary norandrosterone traces by gas chromatography combustion isotope ratio mass spectrometry.

On the one hand, 19-norandrosterone (NA) is the most abundant metabolite of the synthetic anabolic steroid 19-nortestosterone and related prohormones. On the other hand, small amounts are biosynthesized by pregnant women and further evidence exists for physiological origin of this compound. The World Anti-Doping Agency (WADA) formerly introduced threshold concentrations of 2 or 5 ng of NA per ml of urine to discriminate 19-nortestosterone abuse from biosynthetic origin. Recent findings showed however, that formation of NA resulting in concentrations in the range of the threshold levels might be due to demethylation of androsterone in urine, and the WADA 2006 Prohibited List has defined NA as endogenous steroid. To elucidate the endogenous or exogenous origin of NA, (13)C/(12)C-analysis is the method of choice since synthetic 19-nortestosterone is derived from C(3)-plants by partial synthesis and shows delta(13)C(VPDB)-values of around -28 per thousand. Endogenous steroids are less depleted in (13)C due to a dietary mixture of C(3)- and C(4)-plants. An extensive cleanup based on two high performance liquid chromatography cleanup steps was applied to quality control and doping control samples, which contained NA in concentrations down to 2 ng per ml of urine. (13)C/(12)C-ratios of NA, androsterone and etiocholanolone were measured by gas chromatography/combustion/isotope ratio mass spectrometry. By comparing delta(13)C(VPDB)-values of androsterone as endogenous reference compound with NA, the origin of NA in doping control samples was determined as either endogenous or exogenous.

Nutritional supplements and doping.

CONTEXT: The problems of doping in sport and the increasing use of nutritional supplements by athletes are issues that intersect to the degree that a large number of supplements may contain substances that are banned in sport. Many supplements contain substances that are associated with significant health hazards. Athletes consuming such supplement products may jeopardize their sporting status, and their health. OBJECTIVES: To clarify and summarize the current status of dietary supplements in general, and to describe specific problems that can be associated with supplement use so that sport physicians might be better prepared to address these issues with their athlete-patients. DATA SOURCE: An analysis of recent and relevant literature accessed through MEDLINE, and interactions with clinicians, laboratory scientists, colleagues, and athletes. CONCLUSIONS: The dietary supplement industry is completely unregulated in the United States; as a consequence, an abundance of supplement products of dubious value, content, and quality are now available around the world. It is known that many supplement products contain substances that are prohibited in sport-typically stimulants or anabolic steroid precursors. Many supplements contain substances (e.g., ephedrine) that have been associated with significant morbidity and mortality. Sport practitioners have particular responsibilities in addressing this issue. Athletes need to be aware of the problems that can follow supplement use, and sport authorities need to ensure that nutritional education and guidance for athletes is of the highest standard. The need for the appropriate regulation of dietary supplements is emphasized.