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Home / Equine Research Bank / J Vet Intern Med / Corticosteroid Administration Enhances the Glycemic, Insulin...
Journal of veterinary internal medicine2025; 39(2); e17305; doi: 10.1111/jvim.17305

Corticosteroid Administration Enhances the Glycemic, Insulinemic, and Incretin Responses to a High-Protein Mixed Meal in Adult Horses.

Abstract: Corticosteroids are used routinely in horses and induce insulin dysregulation (ID). Nutrition is important for ID management and includes low nonstructural carbohydrate (NSC) diets and, often, high-protein ration balancers (RB). Insulin and incretin secretion increase after high-protein meals; corticosteroids may influence these effects. Objective: A high-protein mixed meal will induce hyperinsulinemia and increased concentrations of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) in horses with ID; dexamethasone (DEX) will amplify this effect. Methods: Five horses with naturally occurring ID. Methods: Horses underwent an IV glucose tolerance test and a feed challenge test (FCT; 1 kg RB). Tests were repeated after DEX administration (0.08 mg/kg PO q24h, 7 days). Insulin, glucose, and incretin dynamics were compared pre- and post-DEX. Results: Corticosteroids exacerbated post-prandial hyperinsulinemia and hyperglycemia after a high-protein meal. The FCT area under the curve for insulin (AUC) after DEX was significantly higher than baseline (558 ± 182 μIU/mL × min vs. 257 ± 93.9 μIU/mL × min; p = 0.03). The maximum concentration of GIP (C) after DEX (381 ± 70.6 pg/mL) was significantly higher than baseline (262 ± 13.7 pg/mL; p = 0.013). The AUC for GLP-1 (AUC; 31.1 ± 15.2 vs. 50 ± 20.2 pg/mL; p = 0.19) and the C of GLP-1 (C; 39.1 ± 25.3 vs. 29.6 ± 12.2 pg/mL; p = 0.32) did not differ between DEX and baseline. Conclusions: Metabolic responses to a high-protein mixed meal were exacerbated by corticosteroids. Horses receiving corticosteroids had larger GIP responses, which may enhance post-prandial hyperinsulinemia.
© 2025 The Author(s). Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.
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Publication Date: 2025-03-10 PubMed ID: 40062690DOI: 10.1111/jvim.17305Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research article explores the effects of corticosteroids on the insulin, glucose, and incretin responses in horses after a high-protein meal. It also discusses the implications of these effects for managing insulin dysregulation (ID) in horses.

Objective and Methods of the Study

  • The main objective of this study was to observe if a high-protein mixed meal would result in increased levels of insulin and incretin (chemicals that stimulate insulin release) in horses with insulin dysregulation, and whether the administration of a corticosteroid known as dexamethasone (DEX) amplified this effect.
  • To test these hypotheses, the researchers conducted an Intravenous (IV) glucose tolerance test and a feed challenge test (FCT) using a kilogram of ration balancer on five horses with natural ID.
  • The same tests were repeated after administrating DEX to the horses for a period of seven days.
  • The dynamics of insulin, glucose, and incretins were then compared before and after the administration of DEX.

Findings of the Research

  • The study found that corticosteroids significantly increased the levels of insulin and glucose in horses after a high protein meal, leading to a condition known as post-prandial hyperglycemia and hyperinsulinemia (increased levels of glucose and insulin in the blood after a meal).
  • This was evidenced by the fact that the area under the curve (AUC) for insulin after DEX administration was significantly higher than the baseline measurement.
  • Accordingly, the maximum concentration of glucose-dependent insulinotropic polypeptide (GIP), a hormone that induces insulin secretion, was significantly higher after DEX administration.
  • However, there was no notable difference in the presence of glucagon-like peptide 1 (GLP-1), another incretin, between the baseline and post-DEX measurements.

Conclusion of the Research

  • The study concluded that metabolic responses to a high-protein mixed meal were worsened by the administration of corticosteroids.
  • Moreover, horses on corticosteroids had larger GIP responses, thereby enhancing post-meal increased levels of insulin (hyperinsulinemia).

Cite This Article

APA
Palmer AT, Watts MR, Timko KJ, Pinnell EF, Keefer KA, Gorman O, Hostnik LD, Burns TA. (2025). Corticosteroid Administration Enhances the Glycemic, Insulinemic, and Incretin Responses to a High-Protein Mixed Meal in Adult Horses. J Vet Intern Med, 39(2), e17305. https://doi.org/10.1111/jvim.17305

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English
Volume: 39
Issue: 2
Pages: e17305

Researcher Affiliations

Palmer, Allison T
  • The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA.
Watts, Mauria R
  • The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA.
Timko, Kathryn J
  • The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA.
Pinnell, Erin F
  • The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA.
Keefer, Katelyn A
  • The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA.
Gorman, Olivia
  • The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA.
Hostnik, Laura D
  • The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA.
Burns, Teresa A
  • The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA.

MeSH Terms

  • Animals
  • Horses
  • Insulin / blood
  • Dexamethasone / pharmacology
  • Dexamethasone / administration & dosage
  • Blood Glucose / drug effects
  • Male
  • Incretins / blood
  • Gastric Inhibitory Polypeptide / blood
  • Female
  • Glucagon-Like Peptide 1 / blood
  • Glucagon-Like Peptide 1 / metabolism
  • Diet, High-Protein / veterinary
  • Hyperinsulinism / veterinary
  • Hyperinsulinism / chemically induced
  • Glucose Tolerance Test / veterinary
  • Animal Feed / analysis
  • Adrenal Cortex Hormones / administration & dosage
  • Adrenal Cortex Hormones / pharmacology
  • Horse Diseases / chemically induced
  • Horse Diseases / blood

Grant Funding

  • The Ohio State University College of Veterinary Medicine Equine Research Funds

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