Effects of calcium antagonist, benidipine, on the progression of chronic renal failure in the elderly: a 1-year follow-up.

The number of patients who needs for dialysis therapy is increasing rapidly among the older population. Although control of hypertension can delay or arrest the progression of renal failure, there are lacking of studies about antihypertensive treatment of chronic renal failure in the elderly. We have studied the effects of treating hypertension with a calcium antagonist, benidipine, on renal function and blood pressure in 58 patients (mean age: 71 +/- 9) with hypertension and chronic renal insufficiency (the levels of creatinine ranging from 1.5 to 4.0 mg/dl). The underlying disease included glomerulopathies (in 33), diabetic nephropathy (in 15), and other causes (in 10). Forty two patients who had been treated with other antihypertensive drugs other than angiotensin converting enzyme (ACE) inhibitors, antihypertensive drugs were withdrawn 2 weeks before the entry. At the entry, patients should have sitting systolic blood pressure (SBP) of above 160 mmHg and diastolic blood pressure (DBP) of above 90 mmHg. In total, both SBP and DBP decreased from 169/95+/-12.5/8.9 to 148/81+/-16.1/8.0 mmHg (p<0.001) with remaining the serum creatinine levels from 2.2+/-0.8 vs 2.4+/-1.3 mg/dl (P>0.05). Retrospective analysis revealed that in 4 of 4 patients treated with benidipine and 2 of 3 patients with benidipine and ACE inhibitors with systolic blood pressure more than 160 mmHg at the end of the study, the levels of serum creatinine increased from 2.5+/-0.3 to 2.8+/-0.4 with significance (P<0.05). If systolic blood pressure was reduced less than 159 mmHg, 38 of 48 patients did not show any deterioration of renal function. Compared to the significance of SBP in preserving renal function, DBP did not associate with the changes in renal function. No patients died during the study. One patient had transient ischemic attack and one patient had stroke in benidipine treated group. One patient had angina pectoris in benidipine-ACE inhibitors treated group. The results of our trial seem to give some support for the idea that long-acting calcium antagonists such as benidipine are renoprotective through reduction of SBP in the elderly people with hypertension and chronic renal insufficiency. However, if systolic blood pressure was not reduced below 160 mmHg throughout a year, the substantial declines in renal function would be expected.