Polymorphism in the angiotensin-converting enzyme [ACE] gene and ACE activity in type 2 diabetic patients

ABSTRACT

It has recently been shown that an insertion [I]/deletion [D] polymorphism exists in the angiotensin-converting enzyme [ACE] gene that can affect the serum ACE level. There are three genotypes DD, DI, and II, with the ACE level being highest in DD, intermediate in DI, and lowest in II. The DD genotype has been reported as a genetic risk factor for diabetes mellitus. In the present investigation, 170 patients with type 2 diabetes mellitus [T2DM] and 144 control subjects were studied. The ACE I/D polymorphism was determined by polymerase chain reaction [PCR] utilizing specific primers. ACE activity was determined spectrophotometrically. Distribution of ACE gene [I/D] polymorphism and allele frequencies in patients with T2DM were significantly different from those in control [P < 0.001]; D allele frequency was 51% in T2DM vs. 48% in controls. The level of ACE activity was significantly higher in the DD genotype [91.1 +/- 23.18] than those in ID [60.6 +/- 22.8] and in II genotypes [36.8 +/- 6.9]. There was a significant difference in genotype distribution between the two groups [P < 0.001]. New normal ranges of serum ACE level were determined for each genotype. Moreover, we found test sensitivity to be 62.3%. Serum ACE activity was significantly associated with ACE [I/D] gene polymorphism