Vascular Effects of Carvedilol Versus Metoprolol in Hypertensive Patients With Type 2 Diabetes

Effects of Carvedilol and Metoprolol on Endothelial Function in Hypertensive Patients With Type 2 Diabetes Mellitus

The purpose of this study is to compare the vascular effects of two commonly used blood pressure medications, carvedilol and metoprolol in hypertensive patients with type 2 diabetes.

Carvedilol and metoprolol are two commonly used blood pressure medications that have both been shown to be effective in controlling hypertension. Although in the same drug class, preliminary data have shown that these medications may have different vascular effects. This study will assess which medication is better at improving artery health independent of their blood pressure lowering effects. Artery health will be assessed non-invasively by ultrasound. Certain markers of atherosclerosis found in the blood will also be measured.

Inclusion Criteria:

• Age 30-80 years old
• Documented history of type 2 diabetes
• Stable angiotensin converting enzyme/angiotensin receptor blocker (ACE/ARB) regimen 30 days before and throughout the study period
• Stable anti-diabetic regimen throughout the study period
• Body mass index (BMI) between 22-45 kg/m2
• HbA1c between 6-9% for patients on anti-diabetic treatment regimen and HbA1c between 6-8% for patients who are being controlled by diet alone
• Screening blood pressure (BP) > 130/80 (average of 3 sitting measurements), with current medications

Exclusion Criteria:

• Uncontrollable or symptomatic arrhythmias
• Unstable angina
• Sick sinus syndrome or second or third degree heart block
• Decompensated heart failure
• Myocardial infarction (MI) or stroke within 3 months of screening
• Bradycardia
• Chronic obstructive pulmonary disease (COPD) with required inhaled or oral bronchodilators or corticosteroids
• Bronchial asthma or related bronchospastic conditions
• New onset/diagnosed type 2 diabetes (<3 months)
• Clinically significant renal or liver disease (creatinine >2.5 mg/dL)
• Endocrine disorders
• Use of anorectic or other diet drugs inconsistent with recommendations for type 2 diabetics
• Use of beta-blockers within 3 months of screening
• Use of corticosteroids
• Systemic disease, including cancer, with reduced life expectancy (<12 months)
• Psychological illness/condition that interferes with comprehension of study requirements
• Use of an investigational drug within 30 days of entry into study