To compare the effect of the antihypertensive drugs nitrendipine and enalapril on the excretion of epidermal growth factor (EGF) and albumin in hypertensive non-insulin-dependent diabetes mellitus (NIDDM) subjects.
After a 4-week washout period, mildly hypertensive (systolic blood pressure [sBP] > 140 mmHg and/or diastolic blood pressure [dBP] >90 mmHg) NIDDM patients with albuminuria (15-200 μg/min) were randomized into an 8-month-long therapy with either nitrendipine (n = 11) or enalapril (n = 10). Blood pressure, EGF, and microalbumin excretion were measured at baseline and throughout the treatment period.
A significant fall in sBP was noticed in the enalapril group and in dBP in the nitrendipine group. In the enalapril group, EGF excretion progressively increased from 188 to 214 nmol/mmol creatinine after 6 weeks and to 274 after 8 months of therapy (P = 0.03). There was a significant fall in albumin excretion while patients were on enalapril, but in the nitrendipine group, neither albuminuria nor EGF excretion changed significantly. There was no correlation of improved EGF excretion with a decrease in albuminuria or BP.
The angiotensin-converting enzyme inhibitor enalapril has been effective in decreasing albumin and increasing EGF excretion. Measurement of urinary EGF may provide a new valuable index of renal function.
