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

Abstract

Background: It 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). Methods: A 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 10 mg treatment (n=38) or amlodipine 5 mg treatment (n=36). Results: Urine albumin to creatinine ratio (ACR) reduction was similar between the two groups at 12 weeks (−53.0±123.2 mg/g in cilnidipine group and −35.7±83.6 mg/g in amlodipine group, P=.29) or 24 weeks (−57.3±106.9 mg/g in cilnidipine group and −20.0±110.4 mg/g in amlodipine group, P=.24). In a subgroup analysis, cilnidipine treatment showed a larger ACR reduction than amlodipine treatment at 12 weeks (−84.7±106.8 mg/g in cilnidipine group and −9.5±79.2 mg/g in amlodipine group, P=.01) and 24 weeks (−84.0±111.7 mg/g in cilnidipine group and 14.6±119.4 mg/g in amlodipine group, P=.008), particularly in patients with a longer duration of diabetes more than 10 years. Conclusions: Cilnidipine 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.