The Effect of Exenatide Compared to Lantus Insulin on Vascular Function in Type 2 Diabetes

Study Summary

The main goals of the study are to evaluate the effect of Exenatide on endothelial-dependent vasodilation, as measured by flow mediated dilation (FMD), to evaluate the effect on endothelial-independent vasodilation, as measured by nitroglycerin (TNG) response, and to evaluate the effect on arterial stiffness, as measured by pulse wave analysis (PWA). We will also measure the effects on various markers of endothelial function, subclinical inflammation, fibrinolysis, and oxidative stress. The control group for the study will receive Lantus insulin, with a goal of similar glycemic control between the treatment and control groups. Specific Aims We will test the following hypotheses: 1. Treatment of patients with type 2 diabetes who are inadequately controlled by monotherapy with a Sulfonylurea (SU) or Metformin, or on combination therapy of a SU and Metformin with Exenatide (GLP-1 mimetic) will result in improved endothelial dependent vasodilation, as measured by FMD, as compared to the control group, who will be treated with Lantus insulin to achieve comparable HbA1c levels. 2. Treatment with Exenatide (GLP-1 mimetic) will result in improved arterial stiffness, as measured by AI by PWA, as compared to the control group, who will be treated with Lantus insulin to achieve comparable HbA1c levels. 3. Endothelial dependent vasodilation, as measured by FMD, and arterial stiffness, as measured by AI, measured in the postprandial state (following a standard test meal) will be improved following treatment with Exenatide as compared to treatment with once daily basal insulin (Lantus). 4. Treatment will result in no improvement in endothelial-independent vasodilation, as measured by a response to TNG, as compared to the control group, who will be treated with Lantus insulin to achieve comparable HbA1c levels. 5. Treatment with Exenatide, compared with treatment with Lantus, will result in a reduction in various plasma markers of inflammation (CRP, TNFA, IL6), endothelial acti

Primary Outcome

Flow mediated dilation (FMD) of the brachial artery was measured at rest and during reactive hyperemia using a high-resolution 10.0 MHz linear array transducer and an HOI Ultramark 9 system. Reactive hyperemia was produced by inflating a pneumatic tourniquet on the forearm distal to the brachial artery to 50 mmHg above the systolic BP for 5 minutes, then deflating it . Brachial artery diameter was measured before inflation of the cuff and 1-2 minutes after cuff deflation and expressed as the per

Interventions

• DRUG Exenatide
• DRUG Glargine Insulin