Coreg CR, Blood Vessel Stiffness and Blood Vessel Function

• Status: Unknown status
• Trial end date: 2009-04-01
• Target enrollment: 0
• Participant gender: All

Summary

We are comparing the blood pressure-lowering effects of two marketed medications, Coreg CR and Toprol XL. Although both drugs reduce blood pressure by blocking the action of noradrenaline on beta-receptors in the blood vessels, Coreg CR also blocks alpha-receptors, which may provide added blood pressure-lowering. In addition, Coreg CR may have anti-oxidant actions. Cells which line blood vessels (termed "endothelial cells") make nitric oxide (NO), which relaxes the muscle cells encircling the blood vessels, causing a reduction in blood pressure. When body cells use oxygen, they normally produce "free radicals", which can destroy NO,leading to high blood pressure, heart damage and worsenimg of diabetes. Antioxidants remove free radicals and prevent or repair this damage. In this study we will measure endothelial cell function, blood vessel wall stiffness, NO in exhaled breath, and blood levels of substances which reflect NO production and destruction to determine if a pure beta-blocker (Toprol XL) differs from an alpha/beta blocker (Coreg CR) in these effects. We will also examine the mechanism by which such differences might occur.

• Phase: Phase 4
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: State University of New York - Downstate Medical Center
• Treatments: Carvedilol; Metoprolol; Nitric Oxide

Criteria

Inclusion Criteria:

1. Type 2 diabetes mellitus,

2. Stable antidiabetic regimen for 3 months

3. Hemoglobin A1c <8.6%

4. Stable antihypertensive medication regimen for 3 months or more, including either an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker

Exclusion Criteria:

1. Any clinically significant abnormality on history, physical examination, or laboratory testing which could preclude safe completion of the study

2. Significant cardiac conditions

3. Lung disease

4. Cigarette smoking

5. Chronic kidney disease (Stage 3 or greater)

6. Type 1 diabetes

7. Known contraindication to alpha- or beta-blocker therapy