Possibly of interest to those who've been following all the doping scandals of late ... ================================================================== A Brief Review of Nandrolone Doping Control Procedures By Dr Simon Davis, Lawrence Berkeley National Laboratories, MS70a 3363, 1 Cyclotron Rd, Berkeley, CA 94720. Fax: (530) 236 7627, e-mail: [EMAIL PROTECTED] Home Summary 1. Nortestosterone (nandrolone) and its metabolites occur naturally in up to 50% of individuals who are known not to have committed a doping offense. 2. Up to 11% of individuals who have not committed a doping offense have been found to have nortestosterone metabolite concentrations greater than 2 ng per mil in their urine. 3. External factors, such as exercise, can quadruple nortestosterone metabolites in urine samples (provided by individuals who are known not to have committed a doping offense). 4. Internal IOC memorandums show that IOC accredited laboratories are aware that nortestosterone metabolites occur naturally in urine. 5. Current analytical protocols do not take into account urine dilution of metabolites, rendering any reported measure of concentration meaningless. 6. It is not possible to determine that a doping offense has been committed solely on the basis of the detection of nortestosterone metabolites in a urine sample. 7. The detection of 19-norandrosterone and 19-noretiocholanolone should be treated in the same manner as a high testosterone / epitestosterone ratio, with a full contemporaneous scientific investigation being carried out before a sample is declared positive. 8. The only valid scientific method for determining the origin of 19-norandrosterone and 19-noretiocholanolone is the measurement of the metabolites 13C/12C ratio, thus enabling a distinction to be drawn between metabolites originating from synthetic or endogenous nortestosterone. Evidence for naturally occurring nortestosterone metabolites in urine samples. Currently, if 19-norandrosterone and 19-noretiocholanolone are detected in a urine sample, IOC regulations consider this to be conclusive evidence that a doping offense has been committed. Under this premise the sole reason for detection of these urinary metabolites is ingestion / injection of nortestosterone (Nandrolone) or a nortestosterone pre-cursor by an athlete . Work by Bjorkeim et al. (1982) and Keiman et al. (1988) have, however, contradicted this hypothesis. These studies indicated that nortestosterone and its metabolites occur naturally in humans as intermediaries during the production of estrogenic compounds. Le Bizec et al. (1999) recently published results showing that more than 50% of individuals tested voided urine containing 19-norandrosterone and 19-noretiocholanolone (all individuals in the study were known not to have committed a doping offense). As a result, 50% of these individuals would have produced false positives if tested under IOC protocols. In the light of such evidence the secretary of the IOC Sub-Commission for Doping & Biochemistry of Sport, Dr Jordi Segura, distributed a memorandum on the 22nd of August 1996 to the heads of all the IOC accredited laboratories. The communication stated that only urine samples with a concentration of nortestosterone metabolites equal to or greater than 2 ng per mil should be considered as evidence of a doping offense. This memorandum clearly shows that the IOC recognizes that nortestosterone occurs naturally within individuals who have not committed a doping offense. One question raised by the memorandum, is why the concentration of 2 ng per ml represents the boundary between a positive and negative sample. Work by Debruyckere et al. (1990) has shown that 2 ng per ml is a gross underestimate of the concentration of nortestosterone metabolites which occur naturally within urine. Debruyckere et al. found that more than 11% of all individuals tested produced natural urinary concentrations of nortestosterone metabolites above the 2 ng per ml level. One individual provided a urine sample with 37 ng per ml of nortestosterone metabolites, 18.5 times greater than the level specified by the IOC communiqué (all individuals were known not to committed a doping offence). The concentration of metabolites is also not constant over time, being affected by external stimuli. This was demonstrated by Le Bizec et al. (1999) who demonstrated that exercise, prior to sampling, increased 19-norandrosterone urinary concentrations by a factor of 4. Even if it were possible to determine a point at which metabolite concentrations conclusively proved a doping offence, current IOC protocols would prevent meaningful values of urinary concentration being reported. This is because the current standard analysis does not take into consideration the relative dilution of metabolites in the urine. For example, if an athlete had recently consumed a pint of water, a subsequent urine sample would be diluted, decreasing the observed metabolite concentration. Likewise, an athlete having completed a long run may be dehydrated, resulting in a subsequent urine sample becoming concentrated. This in turn would increase the concentration of any metabolites present within the voided urine. To avoid this problem it is standard scientific protocol to report urinary metabolites relative to time (e.g. ng per 24 hours) or to another urinary component whose excretion is known to be constant (creatine is often used for this purpose). It is clear, therefore, that simply detecting the presence of nortestosterone metabolites in urine, even at high concentrations, is not indicative of a doping offense. As in the case of a high T/E ratio, any individual providing a urine sample containing nortestosterone metabolites should be subject to further scientific investigation before a positive result is declared. References. Bjorkeim I, et al., (1982). Journal of Steroid Biochemistry, 17, 447-451. Debruyckere R, et al., (1990). Proc. Of 4th Symposium On The Analysis of Steroids, S. Gorog (ed.), 363-367. Keiman A, et al., (1988). Journal of Pharm Biomed Analysis, 6, 473-483. Le Bizec B, et al., (1999). J Chromatogr B Biomed Science Applied, 723 (1-2), 157-1572. Shackleton C, et al., (1997). Steroids, 62, 379-387. Home
