• Change in aortic stiffness, as measured by the change in the mean aortic pulse wave velocity [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  

• Changes in left ventricular diastolic stiffness, serum levels of advanced glycation end products, serum biomarkers of collagen synthesis, and serum levels of brain natriuretic peptide [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  

Diastolic heart failure is a life-threatening condition that occurs when the ventricles of the heart become stiff and do not fully relax, preventing the heart from properly filling with blood. The circulation of blood then backs up, and blood collects in the body's organs, primarily the lungs. However, people with diastolic heart failure may have a normal ejection fraction, which is a measure of the amount of blood that the heart pumps out with each heart beat. Having type 2 diabetes may increase the risk of diastolic heart failure. Also, people with both heart failure and type 2 diabetes are more likely to experience poor health and even death than are people with only heart failure. It is possible that diabetes leads to increased stiffness of the ventricles and the aorta, which is the main blood vessel into which the heart empties. Exenatide, part of a class of medications known as glucagon-like peptide-1 (GLP-1) receptor agonists, is a new medication that is currently used to treat elevated blood sugar levels in people with diabetes. Some studies have shown that this class of medications may have a positive effect on the heart and blood vessels. The purpose of this study is to determine the effect that exenatide has on aortic and left ventricular stiffness in people who have type 2 diabetes and diastolic heart failure.

This 12-week study will enroll adults with type 2 diabetes and diastolic heart failure with normal ejection fraction. At a baseline study visit, participants will undergo a physical examination, blood pressure and heart rate measurements, a blood collection, an echocardiogram to obtain images of the heart, and a non-invasive test that measures blood flow in the aorta. Participants will then be randomly assigned to receive either exenatide or usual care. Participants who receive exenatide will inject the medicine twice a day for 12 weeks. At Week 4, these participants will attend a study visit to adjust the medication dosage and to report any problems, and at Week 6, study staff will follow up with participants by phone. All participants will attend a study visit at Week 12 for repeat baseline testing.