To assess the efficacy and tolerance of a diuretic-free antihypertensive therapy with a Ca²⁺ antagonist and an angiotensin-converting enzyme (ACE) inhibitor in patients with non-insulin-dependent diabetes mellitus (NIDDM).

After a 2-wk washout and a 4-wk placebo phase, 47 hypertensive patients with NIDDM randomly received verapamil or enalapril alone and, if blood pressure remained elevated, both agents combined over 30 wk.

Verapamil or enalapril alone normalized blood pressure to < 90 mmHg diastolic in 30 patients; verapamil decreased mean ± SE blood pressure from 159/98 ± 3/1 to 146/87 ± 3/2 mmHg (n = 18, P < 0.001) and enalapril from 166/99 ± 5/2 to 146/86 ± 3/1 mmHg (n = 12, P < 0.001). In 17 patients who were still hypertensive after 10 wk of monotherapy, combination of both drugs decreased blood pressure from 170/104 ± 4/2 to 152/90 ± 4/2 mmHg (P < 0.001). Fasting plasma glucose, glycosylated hemoglobin, serum fructosamine, total lipids, high-density and low-density lipoprotein cholesterol, apolipoproteins A-I and B, creatinine, and urinary albumin-creatinine ratio were not significantly modified.

In hypertensive patients with NIDDM, a diuretic-free therapy based on the Ca²⁺ antagonist verapamil and/or the ACE inhibitor enalapril can effectively decrease blood pressure without adversely affecting carbohydrate and lipid metabolism.