BACKGROUND: The polymorphisms in the components of the renin-angiotensin system (RAS) are important in the development and progression of coronary artery disease (CAD) in some individuals. Our objectives in the present investigation were to determine whether three RAS polymorphisms, angiotensin-converting enzyme insertion/deletion (ACE I/D), angiotensin receptor II (Ang II AT2 - C3123A) and angiotensinogen (AGT-M235T), are associated with CAD in the Saudi population. We recruited 225 subjects with angiographically confirmed CAD who had identical ethnic backgrounds and 110 control subjects. The polymerase chain reaction-restriction fragment length polymorphisms (RFLP) technique was used to detect polymorphisms in the RAS gene.
RESULTS: Within the CAD group, for the ACE I/D genotype, DD was found in 64.4%, 26.3% carried the ID genotype, and 9.3% carried the II genotype. Within the control group, the DD genotype was found in 56.4%, 23.6% carried the ID genotype, and 20% carried the II genotype. The odds ratio (OR) of the ACE DD vs II genotype with a 95% confidence interval (CI) was 2.45 (1.26-4.78), with p = 0.008. For the Ang II AT2 receptor C3123A genotype, within the CAD group, CC was found in 39.6%, 17.8% carried the CA genotype, and 42.6% carried the AA genotype. Within the control group, CC was found in 39.1%, 60.9% carried the CA genotype, and there was an absence of the AA genotype. The OR of the Ang II AT2 receptor C3123A CC vs AA genotypes (95% CI) was 0.01, with p = 0.0001. A significant association with CAD was shown. For the AGT-M235T genotype, within the CAD group, MM was found in 24.0%, 43.6% carried the MT genotype and 32.4% carried the TT genotype. Within the control group, MM was found in 26.4%, 45.5% carried the TT genotype and 28.2% carried the MT genotype. The OR of MM vs TT (95% CI) was 0.79 (0.43 to 1.46), which was insignificant.
CONCLUSIONS: There is an association between the ACE I/D and Ang II AT2 receptor C3123A polymorphisms and CAD, however, no association was detected between the AGT M235T polymorphism and CAD in the Saudi population.