Serum Insulin-Like Growth Factor-I and Pro-Collagen Type III N-Terminal Peptide in Adolescent Elite Athletes: Implications for the Detection of Growth Hormone Abuse in Sport

Abstract

The GH-2000 score rises in early adolescence, reaches a peak in athletes aged 13-16 yr, and then falls. We have found no evidence that the proposed GH-2000 score developed in adults would lead to an unacceptable rate of false-positive results in adolescent athletes, but caution may be required around the time of peak growth velocity.

Interlaboratory Agreement of Insulin-like Growth Factor 1 Concentrations Measured by Mass Spectrometry

“…By the same logic, because the GH-2000 scores will be calculated by use of results from laboratories around the world, improved interlaboratory imprecision will effectively reduce apparent intraindividual variability and make the athlete biological passport a much more sensitive and specific method for detecting doping in sports (13 ). Finally, the deployment of an MS assay across antidoping laboratories will obviate the difficult process of transforming decision thresholds, which is necessary when using new immunoassays (the result of manufacturerdiscontinued immunoassays) or manufacturer-modified immunoassays (1,6,7 ).…”

“…Because each immunoassay platform has different reference ranges for IGF-1, it is difficult to provide specific guidelines for GH disease management. For antidoping applications, serum concentrations of IGF-1 and the N-terminal propeptide of type III procollagen are used in combination to detect GH abuse (5)(6)(7)(8)(9). This use of these 2 biomarkers was recently implemented in the 2012 Olympic Games in London and will soon be adopted in all 33 World Anti-Doping Agency (WADA)-accredited laboratories worldwide.…”

Biochemical markers of bone turnover in tibia fracture patients randomly assigned to growth hormone (GH) or placebo injections

“…Data from two larger studies suggest that there are no major differences in response to GH in different ethnicities [35,36]. It also seems that application of the GH-2000 score which is validated in adults [15], to adolescent athletes does not unacceptably affect the rate of false-positive results [37]. Further, the effect of injury was studied in 145 male and 40 female amateur and professional athletes, for which the severity and type of injury (soft tissue or bony injury) was recorded and blood samples collected at repeated intervals up to 12 weeks after the injury [18].…”

The development of decision limits for the implementation of the GH-2000 detection methodology using current commercial insulin-like growth factor-I and amino-terminal pro-peptide of type III collagen assays

“…1a show the P-III-NP measurements for 2 adolescent athletes, which may reflect the pubertal change in P-III-NP [9]. Their IGF-I and GH-2000 scores were in the normal range.…”

“…These scores have not been standardised to have mean 0 and SD 1 (as in the previous GH-2000 [1] and GH-2004 publications [9][10][11][12][13]), and therefore the original proposed decision limit of 3.72 is no longer relevant.…”