Hypertensive Nephropathy and the Gene for Angiotensin-Converting Enzyme

Abstract

To investigate the genetic determinants for microalbuminuria, we studied an insertion (I)/deletion (D) polymorphism of the angiotensin-converting enzyme (ACE) gene, which influences the plasma ACE level, in 333 consecutive hypertensive patients and 113 normotensive control subjects. The urinary albumin excretion rate was calculated by using a 12-hour urine collection (mean for two consecutive nights from 7 pm to 7 am ) in all 333 hypertensive patients. The ACE D allele frequency did not differ significantly between the hypertensive patients and the normotensive control subjects (0.37 and 0.33, respectively). Among the hypertensive patients, nephropathy (microalbuminuria and albuminuria) was more common ( P <.001) in those with the ACE DD genotype than in those with other genotypes. The D allele frequency in the nephropathy group was significantly higher than that in the normoalbuminuric group (0.45 versus 0.32, χ 2 =10.8, P <.001). These results indicate that ACE I/D polymorphism is a genetic determinant for hypertensive renal disease in hypertensive patients. This polymorphism might be a confounding factor involved in the association between hypertensive nephropathy and cardiovascular events.