Therapeutic Research

Abstract

We investigated the effects of the calcium channel blocker cilnidipine on serum levels of insulin and aldosterone in 15 patients with essential hypertension（age：57.9±10.0 years）. All the patients were treated with 10 mg/day of cilnidipine （Atelec）for 3 to 6 months. Blood pressure, heart rate, fasting plasma glucose （FPG）, HbA1c, fasting serum immunoreactive insulin（F‒IRI）, insulin resistance index as assessed by homeostasis model assessment（HOMA‒R）, plasma ACTH, serum cortisol, plasma renin activity （PRA）, and serum aldosterone were measured before and after 3 to 6 months of treatment. Cilnidipine treatment lowered blood pressure, heart rate, F‒IRI levels, HOMA‒R and serum aldosterone levels. No clinically significant changes in FPG, HbA1c, ACTH, cortisol and PRA levels were observed. No significant correlation between changes in serum aldosterone and heart rate was found. The lack of a significant correlation between change of aldosterone and change of heart rate suggests that the aldosterone‒decreasing effect is attributable to the direct action of cilnidipine on the N‒type Ca channel of the adrenal cortex. We conclude that cilnidipine improves insulin resistance and lowered serum aldosterone levels.