Comparison of the Antialbuminuric Effects of L-/N-type and L-type Calcium Channel Blockers in Hypertensive Patients with Diabetes and Microalbuminuria: The Study of Assessment for Kidney Function by Urinary Microalbumin in Randomized (SAKURA) Trial

Objective: To clarify whether the L-/N-type calcium channel blocker (CCB) cilnidipine is more renoprotective than the L-type CCB amlodipine in patients with early-stage diabetic nephropathy. Methods: In this prospective, multicenter, open-labeled, randomized trial, the antialbuminuric effects of cilnidipine and amlodipine were examined in renin-angiotensin system (RAS) inhibitor-treated patients with hypertension (blood pressure [BP]: 130-180/80-110 mmHg), type 2 diabetes, and microalbuminuria (urinary albumin to creatinine [Cr] ratio [UACR]: 30-300 mg/g). Results: Patients received cilnidipine (n = 179, final dose: 10.27 +/- 4.13 mg/day) or amlodipine (n = 186, 4.87 +/- 2.08 mg/day) for 12 months. Cilnidipine and amlodipine equally decreased BP. The UACR values for the cilnidipine and amlodipine groups were 111.50 +/- 138.97 and 88.29 +/- 63.45 mg/g, respectively, before treatment and 107.93 +/- 130.23 and 89.07 +/- 97.55 mg/g, respectively, after treatment. The groups showed similar changes for the natural logarithm of the UACR, serum Cr, and estimated glomerular filtration rate. Conclusions: Cilnidipine did not offer greater renoprotection than amlodipine in RAS inhibitor-treated hypertensive patients with type 2 diabetes and microalbuminuria.