Very important study. This explains why some horses must have tests AFTER feeding or oral glucose challenge instead of fasting. The response to feeding often tells the story even when fasting tests are normal.
Notice they now call it Insulin Dysregulation, instead of Insulin resistance. A lot of older studies have now become obsolete.
Equine hyperinsulinemia: investigation of the enteroinsular axis during insulin dysregulation
Melody A de Laat, James M McGree, Martin N. Sillence
American Journal of Physiology - Endocrinology and Metabolism Published 3 November 2015 Vol. no.
Compared to other species insulin dysregulation in equids is poorly understood. Hyperinsulinemia causes laminitis, a significant and often lethal disease affecting the pedal bone/hoof wall attachment site. Until recently, hyperinsulinemia has been considered a counter-regulatory response to insulin resistance (IR), but there is growing evidence to support a gastrointestinal etiology. Incretin hormones released from the proximal intestine, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide, augment insulin secretion in several species, but require investigation in horses. This study investigated peripheral and gut-derived factors impacting insulin secretion by comparing the response to intravenous (IV) and oral D-glucose. Oral and IV tests were performed in 22 ponies previously shown to be insulin dysregulated, of which only 15 were classified as IR (IV test). In a more detailed study, nine different ponies received four treatments: D-glucose orally, D-glucose IV, oats and Workhorse-mix. Insulin, glucose and incretin concentrations were measured before and after each treatment. All nine ponies showed similar IV responses, but five were markedly hyper-responsive to oral D-glucose and four were not. Insulin responsiveness to oral D-glucose was strongly associated with blood glucose concentrations and oral glucose bioavailability, presumably driven by glucose absorption/distribution, as there was no difference in glucose clearance rates. Insulin was also positively associated with active GLP-1 following D-glucose and grain. This study has confirmed a functional enteroinsular axis in ponies which likely contributes to insulin dysregulation that may predispose them to laminitis. Further, IV tests for IR are not reliable predictors of the oral response to dietary non-structural carbohydrate.
I figured you wouldn’t mind, and it was easier than trying to paraphrase your words 
I will remove that part then. I think your name is safe on this one though, but I’ll still go take care of it 