Abstract:
Coronary artery disease (CAD) is a complex, multifunctional condition that results
from interactions among various genetic and environmental influences. The genes coding
for endothelial nitric oxide (eNOS) and angiotensinogen (AGT) have been shown as
potential factors in the prognosis of CAD. E298D polymorphism of the eNOS gene,
M235T and T174M polymorphisms of AGT gene have been defined as CAD risk factors.
However, the polymorphisms of eNOS and AGT genes as risk factors for CAD are
controversial. The aim of this present study was to investigate the association between
primary hyperlipidemia, CAD and the polymorphisms of eNOS (E298D) and AGT
(M235T and T174M) compared with healthy normolipidemia. The study included 105
unrelated healthy normolipidemic subjects, 103 hyperlipidemic subjects and 106 CAD
patients. gDNA was extracted from leukocyte by Guanidine-HCl methods. eNOS E298D,
AGT M235T and AGT T174M gene polymorphisms were analyzed by polymerase chain
reaction (PCR) and restriction fragment length polymorphism (RFLP). For eNOS E298D
polymorphism, the frequency of 298DD homozygous genotype was found 2.8% in CAD,
but not found in hyperlipidemic and healthy normolipidemic subjects. However, the DD
variant and D allele distribution frequencies among the three groups showed no significant
differences. For AGT M235T polymorphism, it was found that the increase risk of
hyperlipidemia is associated with higher frequencies of the AGT 235MT genotype
(OR=3.0306, 95% CI: 1.6965-5.4139, p=0.0003) and AGT 235M allele [OR=1.774, 95%
CI: 1.115-2.822, p=0.020]. AGT M235T variants did not show any association with risk
of CAD. The AGT T174M polymorphism also showed no association with risk of
hyperlipidemia and CAD compared with healthy normolipidemia. All polymorphisms
(eNOS E298D, AGT M235T and AGT T174M) showed no significant difference between
male and female, and hypertensive and normotensive in both healthy normolipidemic
subjects and hyperlipidemic subjects. Carriers of AGT 235 non-TT + eNOS EE
(OR=2.675, 95%CI: 1.399 - 5.115, p=0.004) and AGT 235 non-TT + AGT 174 TT
(OR=2.544, 95%CI1.363 - 4.750, p=0.003) genotypes were significantly associated with
the risk of hyperlipidemia. There were no synergistic effects of eNOS E298D gene
polymorphism and both polymorphisms (M235T and T174M) of AGT gene on CAD. In
conclusion, the present study provides evidence that M allele and MT genotype of AGT
M235T gene polymorphism is associated with hyperlipidemia in this studied population.
There were no correlation of eNOS E298D, AGT M235T and AGT T174M genetic
variants on CAD and hypertension in this study