Long-term effects of calcium antagonists on augmentation index in hypertensive patients with chronic kidney disease: a randomized controlled study

Background: Our previous retrospective study showed that benidipine was superior to amlodipine (AM) for reducing proteinuria and preserving the augmentation index (AI) in patients with chronic kidney disease (CKD). Methods: The present study enrolled CKD patients whose blood pressure was not well controlled by an angiotensin receptor blocker (ARB) and a calcium channel blocker other than AM or azelnidipine (AZ). Either AM (5 mg) or AZ (16 mg) was prescribed randomly. Clinical parameters, including proteinuria, serum creatinine, and AI, were measured before initiation of AM or AZ and 1 year later to assess the long-term effect on renal function and central blood pressure. Results: Brachial and central blood pressures were similarly reduced in both groups. However, pulse rate increased in the AM group, but decreased in the AZ group (+3 ± 1 vs. -2 ± 1 bpm, p < 0.0001). The reduction of proteinuria was greater in the AZ group (-29 ± 2 vs. -38 ± 3%, p < 0.01). Improvement of AI adjusted for a pulse rate of 75 bpm was larger in the AZ group than in the AM group (-4 ± 1 vs. -9 ± 1%, p < 0.05). In both groups, estimated GFR remained unchanged throughout the observation period. Conclusion: In hypertensive patients with CKD, combined treatment with AZ and an ARB decreases proteinuria and preferentially improves arterial reflection.