Effects of different blood pressure-lowering regimens on major cardiovascular events in individuals with and without diabetes mellitus: results of prospectively designed overviews of randomized trials

Abstract

Background: Blood pressure (BP) level is a major determinant of cardiovascular morbidity and mortality in individuals with diabetes mellitus. Several guidelines recommend lower BP goals and specific drug classes for these patients. The overviews reported herein were performed to formally compare the effects on cardiovascular events and death of different BP-lowering regimens in individuals with and without diabetes.

Methods: Twenty-seven randomized trials (N = 158 709 participants) that included 33 395 individuals with diabetes and 125 314 without diabetes contributed to these analyses. For each outcome and each comparison summary, estimates of effect and 95% confidence intervals were calculated for patients with and without diabetes using a random-effects model. The constancy of the effects of each treatment regimen in participants with and without diabetes was examined using chi(2) tests of homogeneity.

Results: Total major cardiovascular events were reduced to a comparable extent in individuals with and without diabetes by regimens based on angiotensin-converting enzyme inhibitors, calcium antagonists, angiotensin receptor blockers, and diuretics/beta-blockers (P > .19 for all by chi(2) test of homogeneity). There was limited evidence that lower BP goals produced larger reductions in total major cardiovascular events in individuals with vs without diabetes (P = .03 by chi(2) test of homogeneity).

Conclusions: These overviews showed that the short- to-medium-term effects on major cardiovascular events of the BP-lowering regimens studied were broadly comparable for patients with and without diabetes. Different effects of regimens on intermediate renal outcomes not evaluated in these overviews may still provide a rationale for using specific drug classes in patients with diabetes.