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

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.