Reduction in microalbuminuria by calcium channel blockers in patients with type 2 diabetes mellitus and hypertension-A randomized, open-label, active-controlled, superiority, parallel-group clinical trial

BackgroundIt has been suggested that renoprotection with calcium channel blockers (CCBs) may differ. This study aimed to compare the anti-proteinuric effect of different CCBs in patients with type 2 diabetes (T2D). MethodsA multicentre, randomized, open-label, active-controlled study was performed in seven centres in Korea. A total of 74 patients with T2D and microalbuminuria treated with renin-angiotensin system (RAS) blockers were randomized to a cilnidipine 10mg treatment (n=38) or amlodipine 5mg treatment (n=36). ResultsUrine albumin to creatinine ratio (ACR) reduction was similar between the two groups at 12weeks (-53.0123.2mg/g in cilnidipine group and -35.7 +/- 83.6mg/g in amlodipine group, P=.29) or 24weeks (-57.3 +/- 106.9mg/g in cilnidipine group and -20.0 +/- 110.4mg/g in amlodipine group, P=.24). In a subgroup analysis, cilnidipine treatment showed a larger ACR reduction than amlodipine treatment at 12weeks (-84.7 +/- 106.8mg/g in cilnidipine group and -9.5 +/- 79.2mg/g in amlodipine group, P=.01) and 24weeks (-84.0 +/- 111.7mg/g in cilnidipine group and 14.6 +/- 119.4mg/g in amlodipine group, P=.008), particularly in patients with a longer duration of diabetes more than 10years. ConclusionsCilnidipine did not show any additional anti-albuminuric effect compared with amlodipine in patients with T2D and microalbuminuria treated with an RAS blocker. However, the anti-albuminuric effect of cilnidipine might differ according to the duration of diabetes.