ANGIOTENSIN-CONVERTING ENZYME GENE I D POLYMORPHISM IN ESSENTIAL-HYPERTENSION AND NEPHROANGIOSCLEROSIS/

An insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene significantly influences circulating ACE levels and plays a role in the development of target organ damage, that is, left ventricular hypertrophy in essential hypertension (EH), and microalbu minuria in diabetes mellitus. We have examined the role of the I/D pol ymorphism in essential hypertensive patients with renal involvement. T he study was divided in two independent protocols. In protocol 1, we r etrospectively analyzed the ACE genotypes in 37 essential hypertensive patients with a clinical and histopathological diagnosis of nephroang iosclerosis. In protocol 2, ACE genotypes as well as microalbuminuria and renal hemodynamic parameters were investigated in 75 patients with EH with normal renal function and a strong family history of hyperten sion. As control group, 75 healthy subjects with BP < 130/85 mm Hg and no family history of cardiovascular diseases were studied. The ACE va riants were determined by PCR and the genotypes were classified as DD, DI and II. In protocol 1, patients with nephroangiosclerosis displaye d a significant difference in the genotype distribution (57% DD, 27% D I, 16% II) when compared to the control population (25% DD, 64% DI, 11 % II; P < 0.001). There was no significant difference in genotype dist ribution between hypertensive patients with normal renal function (pro tocol 2; 33% DD, 59% DI, 8% II) and the control group. There were no d ifferences in age, blood pressure, microalbuminuria and duration of th e disease among the three genotypes in the EH group from protocol 2. T aken together, these findings suggest that the DD genotype of ACE is a ssociated with histopathologic-proven kidney involvement in patients w ith EH and that this polymorphism could be a potential genetic marker in hypertensives at risk of renal complications.