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Reducing HAL Risk in Insulin Dysregulation

Limiting pure starch and sugar sources in horses with insulin dysregulation might reduce the risk of hyperinsulinemia-associated laminitis (HAL).

Researchers wanted to identify the levels of nonstructural carbohydrates (NSC) that could limit the postprandial insulinemic response in the insulin dysregulated horse. They conducted a crossover study to determine if there were thresholds for pure sources of starch and sugar that augmented the insulin response in horses with insulin dysregulation.

They randomly fed 14 adult horses—6 with insulin dysregulation and 8 without—8 different diets that had various amounts of starch and sugar. The horses were similar in weight. Dietary treatments were formulated using a base of low-nonstructural carbohydrate pellet which contained differing amounts of additional dextrose or waxy-maize and oat-starch powder.

Horses were fed each dietary treatment at a rate of 1 g/kg body weight (bwt) once over 12 weeks. Serial blood samples were collected pre- and up to 240 minutes post-prandially, and positive incremental area under the curve for insulin (IAUCi) was calculated for each horse.

Among the horses without insulin dysregulation, the diets had no significant effect on IAUCi. However, the horses with insulin dysregulation had an increased IAUCi for diets between 0.07–0.13 g of total NSC/kg bwt, depending on the starch and sugar composition.

Horses with insulin dysregulation appear to have a threshold for NSCs of about 0.1 g/kg bwt per meal. Higher levels increase the insulin responses of the horses and put them at higher risk for HAL. MeV

For more information:

Macon EL, Harris P, Bailey, et al. Identifying possible thresholds for nonstructural carbohydrates in the insulin dysregulated horse. Equine Vet J. 2022 Dec. 20 https://doi.org/10.1111/evj.13910 https://beva.onlinelibrary.wiley.com/doi/10.1111/evj.13910