Purpose: To review the evidence supporting the "contraindications" (hypoglycemic unawareness, insulin resistance, and dyslipidemia) usually given as the reasons for not using beta blockers for treating hypertension in patients with diabetes mellitus.
Methods: A research synthesis based on MEDLINE (January 1966 through January 1999), hand searches of pertinent references and textbooks, and consultation with experts.
Results: There is little evidence to support the assertion that beta blockers should be routinely contraindicated in diabetes. Beta blockers have few clinically important effects on hypoglycemic awareness and recovery, insulin resistance and hyperglycemia, or lipid profiles. Moreover, when diabetics have been treated with beta blockers for hypertension or for the secondary prevention of myocardial infarction, they benefit as much, if not more, than nondiabetic patients. There may be circumstances (e.g., hypertensive patients with coronary disease) under which beta blockers are the drugs of first choice for diabetic patients. Recommendations to use agents other than beta blockers for the treatment of hypertension in diabetes are based on these agents' effectiveness against surrogate endpoints, and not their proven benefit in preventing important clinical endpoints.
Conclusions: Except for patients with brittle glycemic control, manifest hypoglycemic unawareness, renal parenchymal disease, or documented intolerance, beta blockers should no longer be considered routinely contraindicated in the presence of diabetes.