To determine whether long-term treatment with an angiotensinconverting enzyme (ACE) inhibitor has a beneficial effect on the urinary microalbumin excretion and renal function in non-insulin-dependent diabetes mellitus (NIDDM) patients, enalapril (5 mg/day) was administered for 48 months.
Fifty-two patients with NIDDM who had persistent microalbuminuria in the range of 20–300 mg/24 h, serum creatinine < 106.1 μM 1.2 mg/dl), supine systolic blood pressure (BP) <150 mmHg, supine diastolic BP <90 mmHg, and HbA1c <10% were divided into four groups. Twenty-six patients with normotension were divided at random into two groups; one group received enalapril (5 mg/day) (NE group), the other did not receive enalapril (NC group). In the same way, 26 other patients who were already well-controlled with nifedipine (30 mg/day) over a long-term period (4–6 years) were divided at random into two groups; one received enalapril (5 mg/day) (HE group), the other did not receive enalapril (HC group).
After 48 months, urinary albumin excretion (UAE) was markedly reduced in group NE from 102.4 ×/÷ 1.3 to 55.5 ×/÷ 1.3 mg/24 h (P < 0.005), whereas no significant change occurred in group NC. In the well-controlled hypertensive groups, a significant reduction in UAE occurred in group HE (P < 0.05), whereas no significant change occurred in group HC. No changes in creatinine clearance, BP, or blood glucose control were seen during the study.
Treatment with enalapril for 48 months may have a beneficial effect on the decline of microalbumin excretion in NIDDM patients.