Improvement of Insulin Resistance in Essential Hypertension by Long-Acting Ca Antagonist Benidipine

To investigate whether the long-acting Ca channel blocker, benidipine improves insulin resistance in patients with essential hypertension, insulin sensitivity was measured using the steady state plasma glucose (SSPG) method in 11 or 14 nonobese and nondiabetic hypertensive subjects before and after treatment with benidipine or placebo, respectively, and 11 healthy control subjects. SSPG level was significantly higher in two hypertensive groups, indicating reduced insulin sensitivity than in controls. SSPG level significantly decreased after benidipine treatment, with a decrease of blood pressure. SSPG level and blood pressure did not change in the placebo group. As for oral glucose tolerance test, the area under the curve of insulin diminished significantly after benidipine treatment. SSPG level significantly correlated with intra-platelet Ca2+ concentrations in 9 hypertensive subjects. The long-acting Ca channel blocker benidipine has partially improved insulin resistance in essential hypertension, contributing to the prevention of atherosclerosis associated with insulin resistance.