Longitudinally monitoring of P‐III‐NP, IGF‐I, and GH‐2000 score increases the probability of detecting two weeks’ administration of low‐dose recombinant growth hormone compared to GH‐2000 decision limit and GH isoform test and micro RNA markers

Abstract

To detect doping with growth hormone (GH), GH isoform and biomarkers tests are available. Both methods use population-based decision limits. Future testing in anti-doping is progressing toward individual-based reference ranges, and it is possible that with such an approach the sensitivity to detect GH doping may increase. In addition to monitoring different proteins, the use of miRNAs as future GH biomarkers has been discussed. Here we have longitudinally studied the serum concentrations of IGF-I, P-III-NP and the different GH isoforms in nine healthy men prior to, during and after two weeks' administration with low doses (1 and 4 IU/day) of recGH. Moreover, three putative miRNAs were analyzed. The results show that 80% of the participants were identified as atypical findings using the GH isoform test. However, the participants were only positive 1.5-3 hours directly after an injection. Only one of the participants reached a GH-2000 score indicative of doping when a population-based decision limit was applied. When IGF-I and P-III-NP were longitudinally monitored, 88% of the participants were identified above an individual upper threshold arbitrarily calculated as three standard deviations above the mean values of four baseline samples. The miRNA levels displayed large intra-subject variations that did not change in relation to recGH administration. Our results show that the GH isoform test is very sensitive in detecting low doses of recGH but with a short detection window. Moreover, longitudinally monitoring of IGF-I and P-III-NP may be a promising future approach to detect GH doping.

Combined administration of microdoses of growth hormone and erythropoietin: Effects on performance and evaluation of GH detection capability using anti‐doping methods

“…This study confirmed the observations of Lehtihet et al 21 on the difficulty of detecting GH microdoses using the methods validated for anti-doping analysis. Only one subject would have been suspected of using GH when tested 24 hours after an injection with the direct isoform test and none with the GH biomarker test.…”

“…IGF‐I was a more sensitive marker than P‐III‐NP with more than half the subjects above the upper limit 24 hours after the fifth dose. This very low effect of GH microdoses on P‐III‐NP probably indicates that only higher doses enable a significant and prolonged increase, as already observed by Lehtihet et al when comparing low doses (1 IU/day) and high doses (4 IU/day). These observations nonetheless support the idea that monitoring intra‐individual variations can be more of a deterrent to GH abuse than the actual methods.…”

“…We opted for a dose of 2 IU/subject (0.02–0.03 IU/kg or 6.5–10 μg/kg) administered at the same time as EPO every 2 or 3 days (6 IU/week). Similarly, Lehtihet et al evaluated GH detection by anti‐doping methods using 1 IU GH/day for the lowest dose for 2 weeks (7 IU/week). In this study the limited amount injected and rapid degradation of GH after a few hours in the body, as well as the elapsed time between each injection, assured a complete washout of the microdose before the new one and thus avoided a cumulative effect.…”

“…observed by Lehtihet et al21 when comparing low doses (1 IU/day) and high doses (4 IU/day). These observations nonetheless support the idea that monitoring intra-individual variations can be more of a deterrent to GH abuse than the actual methods.…”

Studies of athlete biological passport biomarkers and clinical parameters in male and female users of anabolic androgenic steroids and other doping agents

“…Neither of the participants using recGH tested positive with the GH isoform test. We did not conduct the GH2000 biomarker test since in a previous study where recGH doses in the same range were administered, only the GH isoform test could detect recGH . The use of growth hormone releasing peptides/secretagogs was reported in seven participants and surprisingly one was tested positive on ibutamoren (also known as MK‐677), even though according to the questionnaire it was administered as droplets 8 weeks earlier.…”