Angiotensin-Converting Enzyme Inhibitors, Angiotensin II Receptor Blockers and Diabetes: A Meta-Analysis of Placebo-Controlled Clinical Trials

BACKGROUND To determine whether the administration of angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) on top of standard cardiovascular (CV) therapies may reduce the incidence of new onset diabetes (NOD) in placebo-controlled clinical trials.The effects of these drugs on CV and non-CV mortality were also tested. METHODS We performed a meta-analysis of all randomized clinical trials (11 trials, n = 84,363 patients, aged 64.2 +/- 5.86 years), published until 14 March 2010, in which ACE inhibitors or ARBs were compared with placebo and NOD incidence, CV, and non-CV mortality were reported. RESULTS Over an average follow-up of 4.0 +/- 1.0 years, there were 1,284/15,142 (8.5%) cases of NOD in active-treated and 1,411/15,130(9.3%) cases in placebo-treated patients in the ACE inhibitor trials, and 2,330/18,756(12.4%) cases in active-treated and 2,669/18,800 (14.2%) cases in placebo-treated patients in the ARB trials. Overall, active therapy reduced NOD compared to placebo (odds ratio (OR) 95%, confidence interval (CI): 0.8(0.8-0.9); P < 0.01). Both ACE inhibitors (OR 95%, CI: 0.8(0.7-1.0); P = 0.07) and ARBs (OR 95%, CI:0.8 (0.8-0.9); P < 0.01) reduced NOD as compared to placebo. Active treatment reduced CV mortality (OR 95%, CI: 0.9(0.8-1.0); P < 0.01) and had a favorable impact on non-CV mortality (OR 95%, CI: 0.7 (0.9-1.0); P = 0.2) as compared to placebo. CONCLUSIONS Our findings demonstrated that ACE inhibitors or ARBs should be preferred in patients with clinical conditions that may increase risk of NOD, since these drugs reduced NOD incidence. In addition, these drugs have favorable effects on CV and non-CV mortality in high CV risk patients.