The Effects of Nitrendipine on Glucose Metabolism in Patients with Hypertension

This study was destigned to investigate the effects of nitrendipine (NT) on glucose metabolism in patients with uncomplicated mild to moderate essential hypertension, following a drug-free period of two weeks and placebo period of one week, 15 patients (mean age 54.4±10.6 and body mass index 27.7±7.9) were given a single-dose of 20 mg/day nitrendipine. In these patients 4 hours OGTT was performed with 75 gr of glucose, before and after therapy; plasma insulin and C-peptide levels were determined before OGTT and at the first and third hour of OGTT, and erythrocyte K+, Na+ levels before and at the first hour of OGTT. Plasma glucose levels did not change significantly during OGTT before and after NT therapy. Before therapy fasting, first and third hours of OGTT insulin levels were 12.4±5.8 mU/ml, 88.6±51.3 mU/ml, and 15±9.5 mU/ml, respectively, and after therapy 15.9±15.4 mU/ml, 87.2±48.1 mU/ml, 18.2±12.9 mU/ml, respectively. Before therapy, plasma peptide were 2.8±0.8 ng/ml, 6.7±1.7 ng/ml, 4.4±2 ng/ml, while fasting, at the first and third hour of OGTT, respectively, and after therapy 2.6±1 ng/ml, 6.9±2.9 ng/ml, 4.9±2.2 ng/ml, respectively. Insulin and C peptide levels did not change with NT therapy. Before therapy fasting and at the first hour of OGTT erythrocyte Na+ levels (mgNa+/mgHb) were 2.7±1 and 2.8±0.9 erythrocyte K+ levels (mgK+/mgHb) 13.7±2 and 14±1.8, respectively and after therapy erythrocyte Na+ levels were 3±1.2 and 3.4±2, eryth rocyte K+ were 13.7±1.9, 13.3±1.7, respectively. Before and after NT therapy serum sodium and potassium levels were in normal limits. As it is seen, no significant difference was found in erythrocyte Na+ and K+ levels by NT therapy. In conclusion, nitrendipine did not significantly alter the glucose metabolism in hypertensive patients.