Carbohydrate pellets to assess insulin dysregulation in horses.
Authors: de Laat Melody A, Warnken Tobias, Delarocque Julien, Reiche Dania B, Grob Anne J, Feige Karsten, Carslake Harry B, Durham Andy E, Sillence Martin N, Thane Kristen E, Frank Nicholas, Brojer Johan, Lindase Sanna, Sonntag Johanna
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary: Carbohydrate Pellets for Equine Insulin Dysregulation Testing Standardising the oral glucose tolerance test (OGT) in equine practice has long presented challenges, with variations in administration route, dose and carbohydrate formulation complicating the interpretation of results across different laboratories and clinics. De Laat and colleagues evaluated a custom-produced glycemic pellet as a novel alternative to existing glucose challenge protocols, assessing both its practical utility and diagnostic value in a multicenter study of 157 horses and ponies across 31 breeds. The pellets proved palatable to 84% of animals tested, with ponies showing significantly greater acceptance than horses, and those that consumed the entire dose did so rapidly (median 4 minutes), indicating good compliance for a clinical test. Peak insulin and glucose responses occurred consistently at 120 minutes post-consumption, with a serum insulin threshold of 83 μIU/mL (95% CI: 70–99) established as the diagnostic cut-off for insulin dysregulation when using the IMMULITE 2000XPi assay. For equine practitioners, these findings offer a practical, standardised alternative to powder or liquid glucose formulations that may improve test reliability and client compliance, whilst the defined diagnostic threshold provides a reference point for consistent ID diagnosis—though practitioners should verify which assay their laboratory uses, as thresholds may differ between platforms.
Read the full abstract on PubMed
Practical Takeaways
- •Carbohydrate pellets offer a palatable, practical alternative for oral glucose tolerance testing in horses and ponies; expect better acceptance in ponies than horses
- •Use 120-minute post-consumption serum insulin measurement at the 83 μIU/mL threshold with the IMMULITE 2000XPi assay for standardized insulin dysregulation diagnosis
- •The short median intake time (4 minutes) and high acceptance rate make this test more practical and reliable than previous glycemic challenge methods with variable dosing routes
Key Findings
- •Carbohydrate pellets were palatable to 132/157 animals (84%), with ponies showing significantly higher acceptance than horses (P=0.004)
- •Peak blood glucose (6.6 [5.8-7.8] mmol/L) and serum insulin (40.5 [19-99.8] μIU/mL) responses occurred at 120 minutes post-consumption
- •Optimal diagnostic cut-off for insulin dysregulation using the IMMULITE 2000XPi assay at 120 minutes was 83 μIU/mL (95% CI: 70-99 μIU/mL)
- •Median intake time of 4 minutes was positively correlated with acceptance grade (r=0.51; P<0.0001), confirming pellet palatability