The Vascular Effects of Carvedilol Controlled Release (CR) in Abdominally Obese Hypertensive Patients

Study Overview
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Brief Summary
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The purpose of this study is to compare the effects of two different combination therapies for high blood pressure on vascular health.

Detailed Description
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Hydrochlorothiazide (HCTZ) has been a popular choice for the treatment of hypertension mainly due to its efficacy in lowering blood pressure, safety, and cost-effectiveness. Similarly, angiotensin converting enzyme inhibitors (ACE-I), because of their neutral to positive impact on glycemic control, have been a popular choice for addressing hypertension in abdominally obese patients. Furthermore, the ACE-I drug class has been shown to improve vascular endothelial function and inflammation in addition to its blood pressure lowering effects. Conversely, beta-adrenergic receptor blockers (b-blockers) have generally been avoided as first line anti-hypertensive therapy in pre-diabetic patients due to concerns about worsening glycemic control and potential hastening of progression to type 2 diabetes mellitus (T2DM). However, recent data have shown that the 3rd generation b-blocker carvedilol does not negatively affect glucose metabolism and therefore may be a safe and effective choice for blood pressure control in these patients. This neutral glycemic effect is likely due to the fact that carvedilol is a non-selective b-receptor antagonist (blocks both b1 and b2 receptors) with alpha1-receptor blocking properties. In addition, carvedilol possesses anti-oxidant properties and improves endothelial function, potentially making it an attractive anti-hypertensive treatment strategy in patients with abdominal obesity. The combination of carvedilol and lisinopril may be especially effective in reducing blood pressure and may act synergistically to address the impaired vascular function and increased inflammation and oxidative stress present in patients with the metabolic syndrome phenotype. Therefore the primary objective of the current study will be to evaluate the effects of carvedilol CR + lisinopril compared to lisinopril + HCTZ on vascular function in a head to head trial in abdominally obese, hypertensive patients. The secondary objective will be to compare the effects of these two anti-hypertensive therapies on plasma biomarkers of endothelial activation, inflammation, and oxidative stress in these patients.

Official Title
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The Vascular Effects of Carvedilol Controlle Release (CR) + Lisinopril Versus Lisinopril + Hydrochlorothiazide (HCTZ) in Abdominally Obese Hypertensive Patients

Conditions
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Abdominal Obesity, Hypertension

Intervention / Treatment
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* Drug: Carvedilol CR + Lisinopril
* Drug: Lisinopril + HCTZ


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: >18 years old Systolic blood pressure (SBP) >130 and/or diastolic blood pressure (DBP) >85 (or currently taking anti-hypertensive medication) Waist circumference >102 cm (men) and >88 cm (women) Stable cardiovascular medication regimen (or other medications known to affect endothelial function) at least 1 month prior to enrollment and throughout the study Exclusion Criteria: Use of anti-hypertensive medications within one month of randomization (patients may be washed-out from anti-hypertensive medications) Unstable angina History of angina symptoms within 3 months of screening Decompensated heart failure History of myocardial infarction Stroke or coronary artery bypass graft within 3 months of screening Standard clinical contraindications to beta-blocker therapy Standard clinical contraindications to ACE-I therapy Women who are currently pregnant or planning to become pregnant (pregnancy testing will occur at specific intervals throughout study and women will be informed of potential risks during the consenting process; information specific to this risk will be detailed in the consent form) Breastfeeding women Clinically significant liver disease Creatinine > 2.5 mg/dL Hepatic function greater than 3 times upper limit of normal

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Carvediolol CR + Lisinopril, then Lisinopril + HCTZ<br>Subjects were randomly assigned to Carvedilol CR + Lisinopril for three months, then had a washout period of one month, and then were given Lisinopril + HCTZ for the final three months. | Drug: Carvedilol CR + Lisinopril<br>* Participants were given Carvedilol CR + Lisinopril for three months. Oral medication. Carvedilol CR and Lisinopril combination therapy was initiated at 20 mg and 10 mg, respectively. Patients returned one week later and doses of carvedilol CR and lisinopril were increased to 40 mg and 20 mg, respectively, depending on blood pressure.<br>* Other names: Coreg;Drug: Lisinopril + HCTZ<br>* Participants were given Lisinopril + HCTZ for three months. Oral medication. Lisinopril + HCTZ combination therapy was initiated at 12.5 mg and 10 mg, respectively. Patients returned 1 week later and doses of hydrochlorothiazide and lisinopril were increased to 25 mg and 20 mg, respectively, depending on blood pressure levels.<br>* Other names: Hydrochlorothiazide;|
| Active Comparator: Lisinopril + HCTZ, then Carvedilol CR + Lisinopril<br>Subjects were randomally assigned to Lisinopril + HCTZ for three months, then had a washout period for one month, and then were given Carvedilol CR + Lisinopril for the final three months. | Drug: Carvedilol CR + Lisinopril<br>* Participants were given Carvedilol CR + Lisinopril for three months. Oral medication. Carvedilol CR and Lisinopril combination therapy was initiated at 20 mg and 10 mg, respectively. Patients returned one week later and doses of carvedilol CR and lisinopril were increased to 40 mg and 20 mg, respectively, depending on blood pressure.<br>* Other names: Coreg;Drug: Lisinopril + HCTZ<br>* Participants were given Lisinopril + HCTZ for three months. Oral medication. Lisinopril + HCTZ combination therapy was initiated at 12.5 mg and 10 mg, respectively. Patients returned 1 week later and doses of hydrochlorothiazide and lisinopril were increased to 25 mg and 20 mg, respectively, depending on blood pressure levels.<br>* Other names: Hydrochlorothiazide;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Reactive Hyperemic Index by Period (Carvedilol CR + Lisinopril vs. Lisinopril + HCTZ) | Reactive hyperemic index is a measure of endothelial function. This is measured by the ratio of post-occlusion blood volume flow versus the baseline blood volume flow. The outcome reported is the change in this ratio after the first intervention phase compared to after the second intervention phase. | Change from three months to seven months |