Acute Changes in Plasma Glucose and Cardiovascular Disease in Diabetes

Patients with diabetes have an increased risk of sudden cardiac death compared to the general population. Severe hypoglycemia is associated with an increased risk of cardiovascular (CV) disease (CVD) and events, including cardiac arrhythmias and sudden cardiac death; likewise, increased glycemic variability is associated with macrovascular complications and increased mortality. The physiological mechanisms linking hypoglycemia and glycemic variability to CVD and CV events remain unclear. Myocardial work and mechanical dyssynchrony will be measured by speckle tracking echocardiography during euglycemia, hypoglycemia and hyperglycemia in individuals with type 1 diabetes, type 2 diabetes, and without diabetes. Echocardiographic images from three experimental clamp studies - Hypo-Heart 1 (sub-study 1), Hypo-Heart 2 (sub-study 2) and Rapid-Heart - will be included in this study.