Bayesian Individual Limits for IGF-1 Monitoring in Equine Plasma: Implementation in the Equine Biological Passport

Area of Science:

• Veterinary Sports Medicine
• Biochemistry
• Animal Science

Background:

• Abuse of recombinant growth hormone (rGH) in racehorses is a significant concern despite regulations.
• Monitoring GH-associated biomarkers like insulin-like growth factor 1 (IGF-1) is crucial for detecting doping.
• Existing Equine Biological Passport (EBP) systems aim to profile racehorses but require enhanced detection methods.

Purpose of the Study:

• To develop and validate individual IGF-1 limits for the Equine Biological Passport (EBP).
• To establish a complementary tool to single limits for supervising IGF-1 profile stability in horses.
• To detect deviations from a horse's normal IGF-1 levels, indicating potential rGH misuse.

Main Methods:

• Assessed a novel method using individual historical data to set custom IGF-1 limits.
• Validated the method with experimental data.
• Tested the approach on Equine Biological Passport (EBP) data from Thoroughbreds and French Trotters.

Main Results:

• Individual IGF-1 limits were found to be an effective complementary tool for monitoring horse profiles.
• The method successfully identified deviations indicative of potential doping.
• The developed individual limits have been integrated into the French EBP for IGF-1 monitoring.

Conclusions:

• Individual IGF-1 limits enhance the Equine Biological Passport's ability to detect doping.
• This approach provides a more personalized and sensitive method for supervising racehorse health and integrity.
• The integration into the French EBP marks a significant advancement in anti-doping strategies in equine sports.