Growth Hormone Doping in Sports: A Critical Review of Use and Detection Strategies

• Published in: Endocrine reviews 2012-04, Vol.33 (2), p.155-186
• Main Author: Baumann, Gerhard P
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Athletes; Biological and medical sciences; Biomarkers; Collagen (type III); Doping; Doping in Sports - methods; Effectiveness; Fundamental and applied biological sciences. Psychology; Growth hormones; Human Growth Hormone - administration & dosage; Human Growth Hormone - adverse effects; Human Growth Hormone - analysis; Humans; Insulin-like growth factor I; Isoforms; Molecular Sequence Data; Peptide Fragments - administration & dosage; Peptide Fragments - adverse effects; Peptide Fragments - analysis; Performance-Enhancing Substances - administration & dosage; Performance-Enhancing Substances - adverse effects; Performance-Enhancing Substances - analysis; Protein Isoforms; Saliva; Substance Abuse Detection - methods; Vertebrates: endocrinology
• ISSN: 0163-769X; 1945-7189
• DOI: 10.1210/er.2011-1035

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.