3:30 p.m. CT Monday, June 15
Insulin exerts several opposing hemodynamic vascular actions, including stimulation of nitric oxide-mediated vasodilation and endothelin-1-mediated vasoconstriction. In type 2 diabetes mellitus, a preferential stiffening of central over peripheral arteries has been reported, though a mechanism for this finding is currently unknown. Here we provide the first evidence that four hours of moderate hyperglycemia unmasks an action of physiologic hyperinsulinemia to increase central aortic stiffness (as measured by cfPWV) in healthy humans. Hyperglycemic-hyperinsulinemia preferentially stiffens central aorta and increases the central-to-peripheral arterial stiffness gradient, while euglycemic-hyperinsulinemia does not. This increase of the central-to-peripheral arterial gradient is classically seen in vascular aging and may identify a mechanism that explains how diabetes causes both micro- and macrovascular damage.