Advantages of a third-generation beta-blocker in patients with diabetes mellitus.

beta-Blocker use improves outcomes even more for the patient with diabetes mellitus than for the patient without diabetes with a history of acute myocardial infarction or coronary artery disease. beta-Blockers facilitate shifting the metabolism of the myocardium away from free fatty acid toward glucose utilization, thereby reducing the cardiac workload and myocardial ischemia. beta-Blockers are also able to reverse the fetal gene induction program to reverse myocardial remodeling and improve ventricular function. Side effects of beta-blockers in the patient with diabetes include increased insulin resistance with worsening glycemic control, elevated triglyceride levels, and lowered levels of high-density lipoprotein cholesterol. Increased frequency of hypoglycemia and its lack of recognition can also be a problem in the insulin-deficient patient but is a minimal problem with the patient with type 2 diabetes. In addition, vasoconstriction, caused by unopposed alpha-activity, can worsen peripheral vascular disease. However, carvedilol, a nonselective beta-blocker with vasodilating and insulin-sensitizing properties, can largely circumvent these problems and is the ideal beta-blocker for the patient with diabetes.