Coreg CR, Blood Vessel Stiffness and Blood Vessel Function
Recruitment status was Recruiting
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.
Drug: metoprolol extended release
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
|Official Title:||Effect of Coreg CR on BP, Endothelial Function, Exhaled Nitric Oxide, and Nitric Oxide Production and Oxidation|
- Effect of Coreg CR compared to Toprol XL on endothelial function, vascular compliance, and parameters of oxidative stress from time of randomization to study drug termination [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
|Study Start Date:||April 2008|
|Estimated Study Completion Date:||April 2009|
|Estimated Primary Completion Date:||December 2008 (Final data collection date for primary outcome measure)|
Coreg Cr will be up-titrated as needed to achieve blood pressure <130/80
capsules in doses of 20, 40, and 80 mg; once daily; 12 weeks duration
Other Name: Coreg CR
Active Comparator: 2
Toprol XL will be up-titrated at weekly intervals to achieve a blood pressure <130/80 mm Hg
Drug: metoprolol extended release
tablets in doses 50, 100, and 200 mg; once daily; 12 weeks duration
Other Name: Toprol XL
The following techniques will be used:
Endothelial function will be measured non-invasively by flow-mediated changes in pulsatile blood volume in the finger-tips.
Vascular compliance (stiffness) will be assessed by tonometry of the radial pulse wave ("augmentation index") and diastolic puse wave analysis.
Plasma nitrate/nitrite levels mirror NO production and will be measured spectrophotometrically by the Griess reaction.
Plasma nitrotyrosine, an in vivo marker of NO-dependent damage induced by reactive nitrogen intermediates derived from NO, will be measured by ELISA.
Exhaled NO may provide an real-time measure of endothelial cell NO production and can be measured by a hand-held device which contains an electrochemical detector sensitive to 5 ppb.
|Contact: Nathaniel Winer, M.D.||firstname.lastname@example.org|
|Contact: Rozina Rana, M.D.||email@example.com|
|United States, New York|
|SUNY Downstate Medical Center||Recruiting|
|Brooklyn, New York, United States, 11203|
|Contact: Nathaniel Winer, M.D. 718-270-6320 firstname.lastname@example.org|
|Contact: Rozina Rana, M.D. 516-279-8092 email@example.com|
|Principal Investigator:||Nathaniel Winer, M.D.||Stae University of New York Downstate Medical Center|