The Impact of Fitness and Mineralocorticoid Receptor Blockade on Vascular Dysfunction in Adults With Type 1 Diabetes

In this protocol, 60 subjects with DM1 will be studied at baseline, after 12 weeks of MCR blockade or 12 weeks of exercise, and again after an additional 12 weeks of MCR blockade, exercise or the combination of both interventions. The investigators will assess function in conduit (pulse wave velocity-PWV, flow-mediated dilation-FMD and augmentation index-AI), resistance (post-ischemic flow velocity-PIFV) and heart and skeletal muscle microvascular (contrast enhanced ultrasound-CEU) vessels before and after 2 hrs of a euglycemic insulin clamp. We hypothesize that compared to healthy controls, both baseline and insulin-responsive vascular function are impaired throughout the arterial vasculature by DM1 and that exercise training and/or mineralocorticoid receptor (MCR) blockade will improve both baseline and insulin-responsive pan-arterial function.