A systematic review including 18 RCTs with a total of 1,286 subjects was abstracted in DARE. Included were RCTs published after 1987, comparing at least 2 drugs of interest (atenolol, celiprolol, enalapril, nifedipine, doxazosin, indapamide), with a treatment duration of at least 4 weeks. When between-trial differences regarding baseline blood pressure (BP) were taken into account, there were no statistically significant differences between the effects of each of the drugs on BP. Atenolol significantly reduced high density lipoprotein cholesterol (mean change –13.8% (p<0.001) and increased low density lipoprotein cholesterol (mean change 1%, p<0.01), triglycerides (mean change 26%, p<0.001), and total cholesterol (mean change 1%, non-significant) compared with other antihypertensives. The Framingham formula scores for diastolic and systolic BP improved on all drugs, but the improvement with atenolol use was significantly less compared with other drugs.
Another systematic review abstracted in DARE included 474 studies of 85 antihypertensive agents and more than 65 000 patients. The studies compared lipid levels before and after treatment. 56 trials compared the effect of monotherapy with those of placebo. Cholesterol levels increased when patients were treated with diuretics (regression coefficient = 0.13 mmol/L; 95% CI 0.09 to 0.18). Beta-blockers increased triglyceride levels (0.35 mmol/L, 95% CI 0.31 to 0.39), except agents with intrinsic sympathomimetic activity. Alpha blockers reduced total cholesterol (-0.23 mmol/L, 95% CI -0.28 to -0.18), LDL cholesterol (-0.20 mmol/L, 95% CI -0.25 to -0.15), triglycerides (-0.07, 95% CI -0.11 to -0.03), and, in younger persons, increased HDL cholesterol (0.02, 95% CI 0.01 to 0.04). ACE inhibitors reduced triglycerides (-0.07, 95% CI -0.12 to -0.02), and in diabetic patients, total cholesterol levels (-0.22, 95% CI -0.34 to -0.10 mmol/L). Vasodilators reduced total (-0.22, 95% CI -0.30 to -0.10) and LDL cholesterol (-0.22, 95% CI -0.29 to -0.11) and increased HDL cholesterol (0.06 mmol/L, 95% CI 0.02 to 0.09).
Comment: The quality of evidence is downgraded by limitations in review methodology (inadequate reporting of the quality of the original studies)