Effect of oral aleurone supplementation on glucose and insulin dynamics of horses in training

Abstract

Aleurone is known to have positive effects on energy metabolism in pigs and mice. Our aim was to study the effect of oral aleurone supplementation on glucose and insulin dynamics in healthy trained horses in a cross-over training trial. Sixteen Standardbred mares (3-4y) were trained for 2 periods of 8 weeks, fed iso-energetic diets with and without 200 gr/day aleurone. A frequently sampled intravenous glucose tolerance test (FSIGTT) and an oral glucose tolerance test (OGTT) were executed before and after each training period. For the OGTT outcome variables included: Maximumglucose, AUCglucose, Maximuminsulin, AUCinsulin, and Time to peakinsulin; for the FSIGTT: acute insulin response to glucose (AIRg), insulin sensitivity (SI), glucose effectiveness (Sg) and disposition index (DI). Either a paired T-test was applied or a paired Wilcoxon test. Training without aleurone induced significant OGTT variable changes, which were not seen in the FSIGTT. OGTT Maximuminsulin was significantly lower (P=0.005); Time to peakinsulin was higher (P=0.03) and AUCinsulin was lower after training (P=0.001). Training with aleurone decreased AIRg (P=0.03) and increased Sg (P=0.02). When comparing the FSIGTT variables after training with aleurone to those after training without aleurone AIRg was significantly lower in the aleurone fed group (P=0.004). Aleurone has a beneficial effect on glucose and insulin dynamics on top of training in healthy horses. This is attributable to increased tissue glucose uptake capacity. However, more research is needed to elucidate the mode of action of aleurone at the level of the skeletal muscle and the gut.