One-year results of an open-label study on antiproteinuric effect of benidipine in elderly patients with chronic kidney disease

Background: The long-term antiproteinuric effects of benidipine, a calcium channel blocker (CCB), have not been evaluated in detail in hypertensive patients with chronic kidney disease (CKD). Methods: Benidipine (4 mg/day) was administered to previously untreated hypertensive patients with CKD, or hypertensive patients with CKD not achieving target blood pressure (BP) despite taking an angiotensin II receptor blocker (ARB). The patients were followed up for 1 year. If target BP was not achieved by 2 weeks after the start of benidipine treatment, the dosage was increased to 8 mg/day. The urinary protein to creatinine (UP/cre) ratio was evaluated before and after benidipine treatment. Results: This study evaluated 65 hypertensive patients with CKD. BP (systolic/diastolic) decreased from 154 +/- 19 / 91 +/- 12 mm Hg before treatment to 134 +/- 16 / 78 +/- 10 mm Hg at 1 year after treatment (p<0.001). The UP/cre ratio decreased significantly from 2.21 +/- 2.47 g/g creatinine (g/g cre) before treatment to 1.43 +/- 2.21 g/g cre after treatment (p<0.001). In both the untreated and ARB-treated groups, the BP and UP/cre ratio decreased significantly at 1 year after treatment. The percentage change in the UP/cre ratio was signifi-cantly greater in patients aged 65 years or older than in those less than 65 years (79.1% vs. 48.7%, p=0.038). Conclusions: Benidipine treatment reduced the UP/cre ratio in hypertensive patients with CKD, and the percentage decrease of the UP/cre ratio was greater in elderly patients, suggesting that benidipine may have more potent antiproteinuric effects in elderly hypertensive patients with CKD.