Optimizing vascular and metabolic responses to insulin in type 2 diabetes : exercise as treatment

Abstract

Title from PDF of title page (University of Missouri--Columbia, viewed on October 24, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. John P. ThyfaultIncludes bibliographical references.Vita.Ph. D. University of Missouri--Columbia 2011."May 2011"[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] The vasodilatory effects of insulin typically account for up to 40% of insulin-mediated glucose disposal; however, insulin-stimulated vasodilation is impaired in individuals with type 2 diabetes, limiting perfusion and delivery of glucose and insulin to target tissues. We have previously demonstrated that exercise prevents insulin resistance and the associated derangements in insulin-stimulated vasodilation in microvessels of rats prone to obesity and diabetes. Here, we describe new evidence indicating that exercise also reverses these derangements. The beneficial effect of exercise on vascular insulin action was consistent across studies of conduit artery blood flow in vivo and microvascular reactivity to insulin in vitro, in both humans and rodents, in response to both short-term and chronic exercise training, and were consistently associated with improvements in indices of glycemic control. Collectively, these data provide strong evidence that exercise is a powerful mediator of the metabolic and vascular effects of insulin