Effects of Direct Renin Inhibition on Atherosclerotic Biomarkers in Patients With Stable Coronary Artery Disease and Type 2 Diabetes Mellitus

Objectives: To evaluate whether the direct renin inhibitor, aliskiren, has a more favorable effect compared to amlodipine on atherosclerotic biomarkers in patients with stable coronary artery disease and diabetes currently receiving standard secondary prevention therapy. Methods: A total of 38 patients were randomly assigned initially to either aliskiren (150 mg daily) or amlodipine (5 mg daily) for 2 weeks after which the dose of either medication was increased to its maximum daily dose for 4 additional weeks. Baseline and 6-week blood samples were analyzed for changes from baseline and between treatment groups for vascular and intracellular cell adhesion molecule, C-reactive protein, nitric oxide, plasminogen activator inhibitor 1, 8-isoprostane, and thiobarbituric acid reactive substances. Results: Thirty-one patients completed the study. More of the dropouts occurred in patients receiving aliskiren. Systolic blood pressure decreased in both treatment arms with no differences between the groups being noted. Plasminogen activator inhibitor 1, nitric oxide, and C-reactive protein concentrations increased in both groups from baseline but changes from baseline or between groups were not significant. Vascular and intracellular cell adhesion molecule, thiobarbituric acid reactive substances, and isoprostane concentrations decreased in each treatment arm from baseline, but these changes were not significant and no differences were noted between the groups. Conclusions: Treatment with either aliskiren or amlodipine did not significantly alter surrogate biomarkers of atherosclerosis in patients with both diabetes and established cardiovascular disease already receiving appropriate secondary cardiovascular prevention therapy. The study is limited in its size and duration to see an effect.