No abstract

Purpose The hydration status of an athlete at the time of a doping control sample collection is an important factor to consider when reviewing athlete biological passports (ABPs). Dehydration results in a reduction of the circulating plasma volume (PV), which may lead to artificially high values of some blood parameters. This study aimed to identify whether serum albumin could serve as a single marker of fluid shifts, which are not currently accounted for in the hematological passport. An additional marker could be used to assist experts when interpreting irregularities in the ABP. Methods Twelve subjects underwent multiple controlled exercise trials designed to induce varying levels of PV shifts. Pre‐exercise blood samples were collected to establish baseline values for individual passports. During exercise interventions, blood samples were collected before the start of exercise and at 10 minute, 1 hour, 2 hours, and 24 hours following exercise. Results Significant increases in hematological parameters – hemoglobin [Hb], hematocrit (HCT), albumin (ALB), and calculated OFF‐score – were identified at varying time points following fluid shift‐inducing exercise. Changes in ALB correlated strongly with changes in [Hb] (r = 0.753) and with estimated PV shifts (r = −0.764). In analyzing ABPs, the resulting increases in Hb did not trigger any atypical findings at 99% specificity. Perspective Monitoring changes in ALB longitudinally may assist experts when reviewing PV shifts in the biological passport.

AOD9604 is a peptide consisting of the C-terminal fragment of human growth hormone from amino acids 177-191 with an additional tyrosine residue at the N-terminus of the peptide. It is reported to mimic the lipolytic properties of growth hormone without the diabetogenic side effects. Therefore, AOD9604 may be used as a performance enhancing drug and is banned by the World Anti-doping Agency (WADA). The peptide is available on several Internet websites and was recently identified in confiscated vials in the USA. To detect abuse of the peptide in athletes, a solid-phase extraction method was validated in urine with a limit of detection of 50 pg/mL. The method has good linearity, precision (<20%), specificity and recovery (62%). Six potential metabolites of the peptide were identified after incubation of AOD9604 in serum and urine. Quantification of the metabolites in serum identified a single metabolite, consisting of amino acids CRSVEGSCG, which is significantly more stable than the other metabolites or the parent compound. Screening for AOD9604 and the stable metabolite may potentially allow an increased window of detection.