Effect of Physical Fitness and Endurance Exercise on Indirect Biomarkers of Recombinant Growth Hormone Misuse: Insulin-Like Growth Factor I and Procollagen Type III Peptide

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.

Aerobic exercise improves hippocampal function and increases BDNF in the serum of young adult males

Physical activity has been reported to improve cognitive function in humans and rodents, possibly via a brain-derived neurotrophic factor (BDNF)-regulated mechanism. In this study of human subjects, we have assessed the effects of acute and chronic exercise on performance of a face-name matching task, which recruits the hippocampus and associated structures of the medial temporal lobe, and the Stroop word-colour task, which does not, and have assessed circulating concentrations of BDNF and IGF-1 in parallel. The results show that a short period of high-intensity cycling results in enhancements in performance of the face-name matching, but not the Stroop, task. These changes in cognitive function were paralleled by increased concentration of BDNF, but not IGF-1, in the serum of exercising subjects. 3 weeks of cycling training had no effect on cardiovascular fitness, as assessed by VO2 scores, cognitive function, or serum BDNF concentration. Increases in fitness, cognitive function and serum BDNF response to acute exercise were observed following 5 weeks of aerobic training. These data indicate that both acute and chronic exercise improve medial temporal lobe function concomitant with increased concentrations of BDNF in the serum, suggesting a possible functional role for this neurotrophic factor in exercise-induced cognitive enhancement in humans.

Detection of GH abuse in sport: Past, present and future

Due to its considered performance enhancing effects, human growth hormone (hGH) is abused as a doping agent in sport. Its misuse also carries potentially serious side effects to a person's health. Consequently, hGH and its releasing factors are prohibited in sport, as established in the Prohibited List which is updated and published yearly by the World Anti-Doping Agency (WADA). In order to fight the menace that hGH doping poses to the spirit of sport and to the health of athletes, the sport movement and the anti-doping authorities, initially led by the International Olympic Committee (IOC) and later by WADA, have put substantial efforts into developing tests for its detection. Currently, a primary analytical approach, the isoform differential immunoassay, has been implemented in WADA-accredited laboratories. In parallel, a second, indirect approach for the detection of hGH abuse, based on the quantification of hGH-associated biological markers, has been developed. The final aim is to combine both methodologies to improve the sensitivity and expand the time window to detect doping with hGH. In addition, novel analytical procedures, based on proteomic and genomic technologies as well as the use of mass spectrometry-based methods of detection, are being investigated for future application in hGH anti-doping tests.

Detection of doping with recombinant human growth hormone

Detection of doping with recombinant human growth hormone is one of the challenges for antidoping analysis. This review focuses on the most important relevant publications that provide insight into the laboratory measurement of human growth hormone (hGH), antibodies and standards, the isoform approach and the biomarker approach. The isoform approach monitors the changes of hGH molecular isoform composition in serum and was applied at the Olympic Games in Athens in 2004, Turin in 2006 and Beijing in 2008. The markers approach detects a formula score, which reflects the changes in concentration of IGF-1 and P-III-P. All these methodologies measure the concentrations of growth hormone and its isoforms for isoform approach, or the concentrations of IGF-1 and P-III-P. All factors that affect these measurements should be taken into account for the development of methods to detect doping with recombinant hGH.

The analytical chemistry of drug monitoring in athletes

The detection and deterrence of the abuse of performance-enhancing drugs in sport are important to maintaining a level playing field among athletes and to decreasing the risk to athletes' health. The World Anti-Doping Program consists of six documents, three of which play a role in analytical development: The World Anti-Doping Code, The List of Prohibited Substances and Methods, and The International Standard for Laboratories. Among the classes of prohibited substances, three have given rise to the most recent analytical developments in the field: anabolic agents; peptide and protein hormones; and methods to increase oxygen delivery to the tissues, including recombinant erythropoietin. Methods for anabolic agents, including designer steroids, have been enhanced through the use of liquid chromatography/tandem mass spectrometry and gas chromatography/combustion/isotope-ratio mass spectrometry. Protein and peptide identification and quantification have benefited from advances in liquid chromatography/tandem mass spectrometry. Incorporation of techniques such as flow cytometry and isoelectric focusing have supported the detection of blood doping.

Quantification of human insulin-like growth factor-1 and qualitative detection of its analogues in plasma using liquid chromatography/electrospray ionisation tandem mass spectrometry

Human insulin-like growth factor-1 (IGF-1) is a peptide hormone that acts as a mediator of most of the somatotropic effects of growth hormone (GH). Therefore, it is supposed to be a biomarker indicating GH abuse in sports as well as diseases associated with a change in IGF-1 plasma concentration. It can be applied locally by injection to increase total protein and DNA content in tissues such as skeletal muscle--a highly desirable effect in various sports disciplines. In order to improve its growth-promoting properties, the primary structure of IGF-1 has been modified, yielding analogues such as des(1-3)IGF-1 and LONGR3IGF-1, which show a considerably reduced affinity to the respective binding proteins in plasma and, thus, an increased bioavailability at target tissues. Due to their capability to enhance performance, IGF-1 and its analogues belong to the prohibited list of the World Anti-Doping Agency. Hence, it was necessary to develop a reliable assay for the quantification of human IGF-1 as well as the detection of its derivatives. Immunoaffinity isolation and purification from 60 microL of plasma followed by liquid chromatography/electrospray ionisation tandem mass spectrometry enabled the unequivocal determination of all target analytes. Diagnostic product ions were characterised utilising an Orbitrap mass spectrometer with high resolution/high accuracy properties and employed for triple quadrupole MS/MS analysis. The described assay provided lower limits of detection (LLODs) between 20 and 50 ng/mL, recovery rates between 34-43% and a precision <15% at the LLOD as well as higher concentration levels. In order to prove the applicability of the developed assay, human plasma samples were analysed and the results were compared with the values obtained from a commercially available immunoradiometric assay (IRMA). Four of six samples resulted in concentration ratios with good correlation between both assays, whereas the absolute concentrations were lower for the presented procedure.