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

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

Association of angiotensin converting enzyme [ACE] gene polymorphism and diabetic nephropathy

Angiotensin I-converting Enzyme [ACE] gene polymorphism; genotype DD or D allele may be involved with an increased susceptibility to type 2 diabetes and diabetic nephropathy [DN]. We examined the frequency of ACE gene polymorphism in 170 patients [85 type 2 diabetes with nephropathy and 85 without it] in Tehran, Iran. DNA was extracted from the white blood cells and the I/D polymorphism of the ACE gene was detected by PCR. The frequency of DD, ID and II genotypes in type 2 diabetic patients were 20%, 61.2% and 18.8%, and in patients with nephropathy 30.6%, 55.3%, 14.1%, respectively. The DD genotype of the DN group was higher than that of the type 2 diabetes patients [30.6% vs 20%, P=0.157, RR=1.3] and the control group [30.6% vs 14.3%, P=0.006, RR=2.9]. The frequency of D allele in nephropathic patients was 58.2% as compared to the type 2 diabetic patients without nephropathy [50.5%] P=0.19, RR=1.16. The D allele frequency in the DN group was found slightly higher than of the type 2 diabetes [X2=0.684, OR=0.709, 95%CI: 0.313-1.606, P=0.408] which indicated the D allele was not associated with DN. It is suggested that DD genotype and D allele are not associated with diabetic nephropathy