Statistical issues in implementing the marker method

Measurement uncertainty in anti-doping quantitative analysis for prohibited threshold substances

The standards of laboratory performance of the World Anti-Doping Agency (WADA)-accredited laboratories are defined in the WADA International Standard for Laboratories and its associated Technical Documents. These sets of rules aim to harmonize the production of valid laboratory test results and evidentiary data as well as the reporting of laboratory analytical findings. The determination of anti-doping rule violations in sport made on the basis of analytical quantitative confirmatory analyses for the presence of prohibited threshold substances, in particular, requires the application of specific compliance decision rules, which are established in the WADA Technical Document on Decision Limits. In this article, the use of measurement uncertainty information in the establishment of compliance Decision Limits and in evaluating the performance of a laboratory’s quantitative analytical procedures over time and in relation to other laboratories through WADA’s External Quality Assessment Scheme program is reviewed and discussed. Furthermore, a perspective is provided on the emerging challenges associated with the harmonization of the quantitative measurement of large-molecular weight biomolecules.

Growth hormone doping in sports: a critical review of use and detection strategies

GH is believed to be widely employed in sports as a performance-enhancing substance. Its use in athletic competition is banned by the World Anti-Doping Agency, and athletes are required to submit to testing for GH exposure. Detection of GH doping is challenging for several reasons including identity/similarity of exogenous to endogenous GH, short half-life, complex and fluctuating secretory dynamics of GH, and a very low urinary excretion rate. The detection test currently in use (GH isoform test) exploits the difference between recombinant GH (pure 22K-GH) and the heterogeneous nature of endogenous GH (several isoforms). Its main limitation is the short window of opportunity for detection (~12-24 h after the last GH dose). A second test to be implemented soon (the biomarker test) is based on stimulation of IGF-I and collagen III synthesis by GH. It has a longer window of opportunity (1-2 wk) but is less specific and presents a variety of technical challenges. GH doping in a larger sense also includes doping with GH secretagogues and IGF-I and its analogs. The scientific evidence for the ergogenicity of GH is weak, a fact that is not widely appreciated in athletic circles or by the general public. Also insufficiently appreciated is the risk of serious health consequences associated with high-dose, prolonged GH use. This review discusses the GH biology relevant to GH doping; the virtues and limitations of detection tests in blood, urine, and saliva; secretagogue efficacy; IGF-I doping; and information about the effectiveness of GH as a performance-enhancing agent.

Growth hormone doping: a review

The use of growth hormone (GH) as a performance enhancing substance was first promoted in lay publications, long before scientists fully acknowledged its benefits. It is thought athletes currently use GH to enhance their athletic performance and to accelerate the healing of sporting injuries. Over recent years, a number of high profile athletes have admitted to using GH. To date, there is only limited and weak evidence for its beneficial effects on performance. Nevertheless the “hype” around its effectiveness and the lack of a foolproof detection methodology that will detect its abuse longer than 24 hours after the last injection has encouraged its widespread use. This article reviews the current evidence of the ergogenic effects of GH along with the risks associated with its use. The review also examines methodologies, both currently available and in development for detecting its abuse.