Comparison of long-term therapeutic effect of an ACE inhibitor, temocapril, with that of a diuretic on microalbuminuria in non-diabetic essential hypertension

Many investigators have reported that angiotensin-converting enzyme (ACE) i nhibitors have antiproteinuric effects and retard the progression of renal impairment in diabetic patients. On the other hand, those effects of ACE in hibitors have not been well established in patients with essential hyperten sion. This study was conducted to prospectively evaluate whether an ACE inh ibitor, temocapril, could modify the urinary microalbumin excretion rate (U AE) in hypertensive outpatients who had no signs of renal impairment. To co mpare the long-term effect of temocapril with that of a diuretic on UAE, hy pertensive patients treated with a diuretic (trichlormethiazide) were enrol led in a prospective study if they had normal serum creatinine levels and n o overt proteinuria during a 3-month screening period. A urinary microalbum in-to-urinary-creatinine ratio(mg albumin/mmol Cr) was used as an estimate of UAE, Patients visited the hospital monthly to determine blood pressure ( BP) and UAE, After baseline observation during the treatment with the diure tic, the subjects were randomly divided into two groups. In group A, the di uretic was switched to temocapril, 2 to 4 mg once daily for 12 months. In g roup B, the subjects continued to receive the diuretic for an additional 12 months. Seventy-six outpatients (41 men and 35 women; mean age, 59.0+/-1.4 years) with essential hypertension entered the study. The effects of temoc april on BP appeared to be clinically similar to those of the trichlormethi azide, but the use of temocapril significantly decreased UAE, In group A (n =37), UAE decreased significantly (p<0.01) from the baseline value of 4.19/-0.37 mg albumin/mmol Cr to 2.47+/-0.29 and 2.68+/-0.28 mg albumin/mmol Cr at the 6th and 12th month of temocapriI therapy, respectively. In contrast , in group B (n=39) UAE was unchanged (baseline, 4.16+/-0.63 mg albumin/mmo l Cr; 6 months, 4.92+/-0.72; 12 months, 4.71+/-0.74). These results indicat e that long-term therapy with temocapril may be superior in reducing UAE th an is diuretic therapy in patients with essential hypertension who had no s igns of renal impairment.