Metabolic properties of vasodilating beta blockers: management considerations for hypertensive diabetic patients and patients with the metabolic syndrome

Abstract

Type 2 diabetes and hypertension are both insulin-resistant states that impose an excessive risk burden for future major cardiovascular events, including coronary heart disease, stroke, and heart failure. beta-adrenergic receptor antagonists are effective for the treatment of hypertension, but they are underused in diabetic patients because of possible adverse effects on carbohydrate and lipid metabolism, including insulin resistance, glucose intolerance, and dyslipidemia. Traditional beta blockers, both nonselective and selective, are vasoconstrictive due to unopposed alpha1 activity; however, vasodilating beta blockers are not associated with these negative metabolic effects. This review discusses the background of insulin resistance and its link to diabetes and hypertension, emphasizing the role of vascular control by the renin-angiotensin and sympathetic nervous systems on insulin sensitivity and glucose utilization. Clinical evidence is reviewed for the use of vasodilating beta blockers in the treatment of hypertension and in reducing cardiovascular risk in the diabetic population.

Figure 1

Relationship between blood pressure and insulin resistance. Adapted with permission from Endocr Pract. 2003;9:43–49. ²⁰

Figure 2

Comparative acute hemodynamic effects of different β blockers. HR=heart rate; CI=cardiac index; Ees=end systolic elastane; PWP=mean pulmonary wedge pressure; SVR=systemic vascular resistance. Adapted with permission from Am J Cardiol. 1997;80:26L‐40L. ³²