Detecting human growth hormone: the ITA launches a targeted project ahead of Paris 2024

Human Growth hormone (hGH), a potent peptide hormone, has been exploited in some sports and disciplines for decades, initially through extraction from cadavers and later through recombinant DNA technology to mainly improve strength and power, as well as muscular endurance. It stimulates growth, cell reproduction and cell regeneration and is medically used as a prescription drug to treat certain growth disorders in children and adult growth hormone deficiency. hGH has been prohibited in sport since the late 1980s by International Sport Federations and the International Olympic Committee (IOC) and is listed on the World Anti-Doping Agency’s (WADA) Prohibited List since its first publication in 2004.

Anti-doping efforts in the mid-2000s introduced a direct detection method based on growth hormone (GH) isoforms differential immunoassays, followed later by the discovery of novel biomarkers that indicate GH action captured in the GH-2000 test. Comprising biomarkers such as insulin-like growth factor (IGF-1) and amino terminal peptide of type III procollagen (P-III-NP), this biomarker-based approach offers a more comprehensive strategy for detecting GH doping. Implemented during the Olympic Games London 2012, these improved detection methods highlight specific markers that remain relatively stable within individuals, making them better at spotting growth hormone doping. While they also extend the time frame for detecting effects of growth hormone abuse, the test relies on general population limits, which are less sensitive due to significant biological differences among people.

In August 2023, WADA introduced new Athlete Biological Passport (ABP) features, including the new Endocrine Module, marking a significant leap in the detection of hGH abuse in sports. The ABP is a tool used in anti-doping to monitor an athlete’s biological markers over time to detect any unusual changes that may indicate doping. It helps improve fair play in sports by providing a more comprehensive and individualised approach to detecting performance-enhancing substances and methods. This newly introduced Endocrine Module is the third ABP module alongside the Haematological and Steroidal Modules. It enables the longitudinal and personalised profiling of hGH biomarkers and is expected to increase sensitivity of hGH abuse detection, as a complementary approach to the existing direct detection methods. The new module tracks changes in IGF-1, P-III-NP and the GH-2000 score over time, enabling better testing strategies, focused athlete testing, and the use of specialised analysis to catch doping violations in sport.

To uphold the spirit of fair play and contribute to strengthening the fight against doping, the ITA initiated an important targeted project in the lead up to the Olympic Games Paris 2024 in collaboration with other anti-doping organisations and international sports federations such as the International Skating Union (ISU), the Athletics Integrity Unit (AIU), the Agence Française de Lutte contre le Dopage (AFLD), the United States Anti-Doping Agency (USADA), UK Anti-Doping (UKAD) and WADA for the rapid implementation of the Endocrine Module and the establishment of athlete profiles across various sports and disciplines. Using samples provided by the participating organisations, the objective is to ensure that a reliable interpretation of the endocrine passports and athlete profiles can be established.

“The work of anti-doping experts depends on the continuous development of the tools and methods available to us to detect prohibited substances,” says Dr. Neil Robinson, ITA Head of Science & Medical. “With the new ABP Endocrine Module, we now have a new tool at our disposal which we must leverage to detect doping. To ensure that it can be used reliably in our daily activities for the Paris 2024 Olympic Games and beyond, we need to work together to better understand how we can monitor hGH biomarkers’ levels in athletes’ bodies over the long term and detect potential abuse. I am very pleased that the ITA can lead this joint effort and thank all the organisations involved for their valuable contributions.”

As a first anticipated milestone for the implementation of the Endocrine Module in the anti-doping program of ITA’s partner International Federations, the targeted testing will improve the knowledge of the Endocrine Module biomarkers and interpretation of athlete profiles across sports where hGH abuse is expected to bring significant athletic advantages. The targeted testing of athletes already or likely qualified for Paris 2024 paves the way for a more comprehensive anti-doping program for the next Olympic Games. In preparation for Paris 2024, the ITA is working closely with the WADA-accredited anti-doping laboratory in Paris (LADF), enhancing measures against hGH abuse in Olympic disciplines. This collaborative effort aligns with the ITA’s commitment to ensuring the integrity of sport and promoting the spirit of fair competition.