Long-term therapy with an ACE inhibitor, temocapril, reduces microalbuminuria in essential hypertension

The present study was conducted to prospectively evaluate whether a new ACE inhibitor, temocapril, could modify urinary microalbumin excretion rate (UAE) in a group of hypertensive outpatients who had no evidence of renal impairment. Sixty-three outpatients (32 men and 31 women; mean age, 59.9 +/- 1.5 yr) with essential hypertension entered the study, all having been treated for at least 6 mo with dihydropyridine calcium-channel blockers (CCBs: nitrendipine, nisoldipine, or amlodipine). Their blood pressures (BPs) had been controlled to adequate levels with the CCBs. None had overt proteinuria (determined by Albustix) or abnormal serum creatinine levels. After 3 mo of baseline observation under the previous treatment, the subjects were randomly divided into two groups. In group A (n = 31), the previously used CCBs were switched to temocapril, 2 to 4 mg once daily for 12 mo, and BP was controlled at a level equivalent to that during CCB treatment. In group B (n = 32), the subjects were maintained on their previous treatment for a further 12 mo. The effect of temocapril on BP appeared to be clinically similar to that of the previously used CCBs, but it significantly decreased UAE as compared with the previous therapy. In group A, UAE decreased significantly (p < 0.01) from the baseline value of 38.9 +/- 5.1 mg/g creatinine (Cr) to 22.2 +/- 4.2 and 25.3 +/- 5.6 mg/g Cr at the 6th and 12th months of temocapril therapy, respectively. In contrast, in group B UAE was unchanged (baseline 39.8 +/- 6.6 mg/g Cr; 6 mo, 44.6 +/- 6.8; 12 mo, 45.9 +/- 7.7). In group A, 17 of 31 patients (54.8%) had abnormal UAE levels (> or = 29.5 mg/g Cr) during previous therapy with CCBs, but 6 mo after switching to temocapril 25 of these patients (80.6%) had normal UAE (< 29.5 mg/g Cr). In group B, 15 of 32 patients (46.9%) had abnormal UAE levels during the observation period, and these abnormal UAE levels remained unchanged; 17 of the 32 patients (53.1%) had abnormal UAE levels after a further 6 mo of continued CCBs therapy. We conclude that long-term therapy with temocapril may provide renal protection by reducing UAE even in hypertensive patients with no evidence of renal impairment.