Comparative Analysis of Beta-Blockers With Other Antihypertensive Agents on Cardiovascular Outcomes in Hypertensive Patients With Diabetes Mellitus: A Systematic Review and Meta-Analysis

Objectives: To analyze the effects of beta-blockers (BBs) on cardiovascular (CV) outcomes in diabetic patients with hypertension. Data Source: Literature search was performed with relevant search words using PubMed and Ovid Gateway search engines for trials published in English from June 1996 to July 2007. Review Methods: Systematic reviews of randomized control trials that used BBs as treatment or control therapy in diabetic patients with hypertension were included for the analysis. All the included studies use intention-to-treat analysis. Two individual authors procured the data. Myocardial infarction, stroke, CV mortality, and total mortality were the outcomes analyzed. Relative risk across the different groups was calculated using Mantel-Haenszel random- and fixed-effects model. Interstudy heterogeneity was computed by x 2 test. Results were calculated with 95% confidence intervals (CIs) and were considered significant with double-sided alpha error less than 0.05. Funnel plot was used to assess for publication bias. Results: Eight trials (N = 130,270) met the inclusion criteria for the analysis. The relative risks for myocardial infarction, stroke, CV mortality, and total mortality were 1.08 (95% CI 0.82-1.42; P = 0.6), 1.13 (95% CI 0.95-1.36; P = 0.1), 1.15 (95% CI 0.83-1.6; P = 0.3), and 1.16 (95% CI 0.92-1.47; P = 0.2), respectively. BBs were associated with increased risk for CV mortality 1.39 (95% CI 1.07-1.804; P < 0.01) when compared with renin angiotensin blockade (RAS) therapy. Conclusion: BBs have increased risk for CV mortality when compared with RAS blockade therapy in diabetic patients with hypertension. BBs do not have increased risk for myocardial infarction, stroke, CV mortality, and total mortality when compared with control antihypertensive therapy in diabetic patients with hypertension.