A COMPARATIVE-STUDY OF LISINOPRIL AND ATENOLOL ON LOW DEGREE URINARY ALBUMIN EXCRETION, RENAL-FUNCTION AND HEMODYNAMICS IN UNCOMPLICATED, PRIMARY HYPERTENSION

The presence of slightly increased urinary albumin excretion (UAE), even at levels well below levels detectable by an ordinary dipstick, has been suggested as a predictor of cardiovascular morbidity and as a reflection of the degree of overall vascular permeability. The aim of the present investigation was to study the effects of two different antihypertensive drug regimens, an ACE inhibitor and a beta-adrenoceptor antagonist, on the low UAE rate observed in subjects with uncomplicated, mild to moderate primary hypertension. After a 4-week placebo run-in period, 49 patients (mean age 54 y) were randomly assigned in a double blind manner either to further 4 weeks on placebo (P, n = 15), 8 weeks on lisinopril (L, n = 17; 20 mg/40 mg o. d.) or 8 weeks on atenolol (A, n = 17; 50 mg/100 mg o. d.). The 24-h UAE was measured every second week. At entry and after 4 weeks the glomerular filtration rate and the renal plasma flow were measured. Both drugs lowered blood pressure (BP) to a similar extent after 4 and 8 weeks of treatment; the blood pressures were 160/106 (P), 159/104 (L) and 154/103 (A) at entry, and 133/83 (L) and 134/87 (A) at the end of the study after 8 weeks. On entry the 24-h UAE in all patients ranged from 4 to 49 mg (mean 14.1 mg), and it did not differ significantly between groups. After 4 weeks the UAE during 24 h was reduced by approximately one third in the lisinopril-treated group, and by 10% in the atenolol treated group, whereas it remained unaltered in the group on placebo. After 8 weeks the 24-hour UAE was approximately 20% lower compared to baseline levels in the lisinopril-treated patients. In the atenolol-treated group the UAE was unaltered compared to baseline. However, none of the changes in the UAE was statistically significant, nor were there any statistically significant differences between the two antihypertensive regimens. Moreover, there were no significant effect of the lisinopril or atenolol treatment on renal function or on renal haemodynamics. It is concluded that in patients with uncomplicated, mild to moderate hypertension both an ACE-inhibitor, such as lisinopril, as well as a beta1-selective adrenocentor blocking agent, such as atenolol, may be used without particular preference with regard to the short-term effects on renal function and haemodynamics, and to the low level of UAE normally observed in such patients.