Effects of isradipine and nifedipine retard in hypertensive patients with type II diabetes mellitus.

Twenty patients were randomized to receive either 2.5 mg isradipine twice daily or 20 mg nifedipine retard once daily for 6 months. After 2 weeks of placebo wash-out, evaluations were carried out every 4 weeks. These evaluations included assessment of blood pressure, lipid profile, hemoglobin A1 sigma glucagon, C peptide, and insulin requirements. Both isradipine and nifedipine retard lowered systolic and diastolic blood pressures to normal values (P < .001). However, isradipine was accompanied by a decrease in heart rate (P < .005). Neither drug modified hemoglobin A1c or the glycemic profile. The endogenous insulin-secretion response decreased in both treatment groups (P < .05). In conclusion, isradipine and nifedipine retard are efficacious in the treatment of hypertension in patients with type II diabetes mellitus, and neither treatment produces modification of metabolic control.