Prevention of microalbuminuria in patients with type 2 diabetes and hypertension.

Background: We have previously demonstrated in the Randomized Olmesartan and Diabetes Microalbuminuria Prevention study that the angiotensin receptor blocker (ARB) olmesartan delays the onset of microalbuminuria in patients with type 2 diabetes. Now, we investigated the effect in the subpopulation with hypertension.
Methods: Overall, 4020 patients with type 2 diabetes and hypertension at baseline (defined by a SBP/DBP ≥130/80 mmHg or use of antihypertensive medication) received either 40 mg olmesartan once daily or placebo for a median of 3.2 years in a randomized, double-blind, multicenter, controlled trial. Additional antihypertensive drugs (except angiotensin-converting enzyme inhibitors or ARBs) were used as needed to lower blood pressure (BP) to less than 130/80 mmHg.
Results: The average BP was 126.3/74.7 and 129.5/76.6 mmHg, respectively (P < 0.001). Olmesartan delayed the time to onset of microalbuminuria by 25% (hazard ratio = 0.75; 95% confidence interval = 0.61-0.92, P = 0.007). Patients with a baseline SBP above the median of 136.7 mmHg and a SBP reduction above the median of 17.45 mmHg had a lower incidence of microalbuminuria than patients with a SBP reduction of less than 17.45 (8.1 vs. 11.2%, P < 0.0001). Independent from the baseline BP and the degree of BP reduction a 15-39% increase in the time to onset of microalbuminuria was detectable by olmesartan treatment. Cardiovascular events were comparable and occurred in 93 (4.6%) patients taking olmesartan and 86 (4.4%) taking placebo.
Conclusion: Patients with a better BP reduction are less likely to develop microalbuminuria. Treatment with olmesartan delayed the onset of microalbuminuria independent of the baseline BP and the degree of BP reduction.