Kanchana Intarajorn. Associations of angiotensin-converting enzyme and angiotensin II type 1 receptor gene polymorphisms on development of coronary artery disease in type 2 diabetic patients. Master's Degree(Biochemistry). Mahidol University. : Mahidol University, 2008.
Associations of angiotensin-converting enzyme and angiotensin II type 1 receptor gene polymorphisms on development of coronary artery disease in type 2 diabetic patients
Abstract:
Diabetes mellitus (DM) is a leading cause of morbidity and mortality, largely
because of its vascular complications. Diabetes and coronary artery disease (CAD) are
a multifactorial diseases whose phenotypic manifestations depend on the interaction of
the patients genetic background with a number of environmental factors. The reninangiotensin
system (RAS) plays a central role in the pathogenesis of cardiovascular
disease and blood pressure. Recently, the gene coding for the components of the RAS
have been investigated as risk factors in cardiovascular disease and hypertension. In
addition to the regulation of blood pressure, the RAS may also affect the other aspects
of the pathogenesis of the metabolic syndrome, such as insulin resistance.
Insertion/deletion (I/D) polymorphism of ACE gene and A1166C polymorphism of
angiotensin II type 1 receptor (AT1R) gene have been characterized and defined as
risk factors in CAD. However, both polymorphisms of RAS as risk factors for CAD
are controversial. In this study, the subjects were divided into 105 healthy controls,
135 T2DM and 100 T2DM with CAD. The genotypes of both genes were determined
by a polymerase chain reaction (PCR). For the AT1R gene, a restriction analysis of the
PCR product was performed. The allele and genotype frequencies of ACE gene were
similar among 3 groups, but the AT1R gene was significantly different (p= 0.001).
The A1166C polymorphism showed an association with independent risk factors of
diabetes when compared with healthy control (adjusted odds ratio for AA genotype =
3.983, 95%CI= 1.502-10.565). Both polymorphisms showed no significant difference
between male and female, and hypertensive and normotensive in both T2DM and
T2DM with CAD patients. The odds ratio for the combination of ACE I/D
polymorphism and AT1R A1166C polymorphism were also not determined as risks
for CAD in T2DM patients. In conclusion, there was no correlation of ACE I/D
polymorphism and AT1R A1166C polymorphism which means that neither gene may
be a genetic marker for the early diagnosis of CAD in T2DM patients. However,
AT1R AA genotype was associated with diabetes resulting in insulin resistance. This
could be a genetic marker for the early diagnosis of diabetes.