Effects of nitrendipine and enalapril on left ventricular mass in patients with non-insulin-dependent diabetes mellitus and hypertension.

Objective: To compare the effects of a calcium antagonist (nitrendipine) and an angiotensin converting enzyme inhibitor (enalapril) with those of placebo on left ventricular mass in patients with non-insulin-dependent diabetes mellitus and hypertension.

Design: A double-blind randomized, placebo-controlled trial.

Setting: General practitioners referred patients to the trial physician.

Patients: The study population comprised 121 patients with non-insulin-dependent diabetes mellitus. Inclusion criteria for blood pressure were diastolic blood pressure 90-115 mmHg and systolic blood pressure < or = 200 mmHg, while subjects were not being administered blood-pressure-lowering drugs for 3 weeks.

Intervention: Patients were randomly allocated to receive nitrendipine (n = 40), enalapril (n = 40) or placebo (n = 41). The treatment period was 48 weeks.

Main Outcome Measures: The effect of nitrendipine was defined as the difference in change in left ventricular mass index from baseline between nitrendipine treatment and placebo after 48 weeks of treatment. The effects of nitrendipine compared with that of enalapril and of enalapril compared with placebo were defined similarly. Left ventricular mass was measured by M-mode echocardiography.

Results: Use of nitrendipine and enalapril led to significant and almost identical reductions in systolic and diastolic blood pressures. During 48 weeks left ventricular mass index decreased by 5% for patients in the nitrendipine group (decrease by 12 g/m2, 95% confidence interval 1-23), remained about the same for patients in the enalapril group (decrease by 1 g/m2, 95% confidence interval decrease by 10 to increase by 9) and increased by 9% for patients in the placebo group (increase by 9 g/m2, 95% confidence interval 2-16).

Conclusion: These results indicate that administration of nitrendipine to patients with non-insulin-dependent diabetes mellitus and hypertension reduces left ventricular mass index. Enalapril appears not to induce regression, but perhaps prevents progression with an effect that is intermediate between those of nitrendipine and placebo.