A T-786C polymorphism in 5'-flanking region of the endothelial nitric oxide synthase gene and endothelium-dependent arterial dilation in Type 2 diabetes.
OBJECTIVE
Several studies have shown that the T-786C polymorphism in 5'-flanking region of the endothelial nitric oxide synthase (eNOS) gene is associated with coronary artery disease in non-diabetic population. In the present study, we attempted to assess whether the T-786C polymorphism of eNOS gene is associated with endothelial dysfunction Type 2 diabetes.


METHODS
A total of 162 Type 2 diabetic men were studied. PCR/allele-specific probes were used to analyse the T-786C polymorphism of eNOS gene, and high resolution ultrasound was used to measure brachial artery diameter at rest, after reactive hyperaemia and after sublingual glyceryltrinitrate.


RESULTS
The flow-mediated arterial dilation among subjects with T/C or C/C was 3.73+/-0.50%, which was significantly lower than that in subjects with T/T (4.15+/-0.49%) (P=0.000). On multiple linear regression analysis, the presence of C allele, mean blood pressure, low-density lipoprotein (LDL) and serum lipoprotein (a) [Lp(a)] were independent determinants for reduced endothelium-dependent arterial dilation (R2=0.175, P=0.0021). The flow-mediated arterial dilation in smokers with T/C or C/C was significantly lower than that in smokers with T/T (P<0.001), but not in non-smokers. In addition, the presence of C allele, LDL and Lp(a) were independent determinants for reduced endothelium-dependent arterial dilation (R2=0.258, P=0.0017) in smokers, but not in non-smokers.


CONCLUSIONS
The C allele of T-786C polymorphism of eNOS gene is a genetic risk factor for endothelial dysfunction in Type 2 diabetic patients, especially among smokers.
Guang-da
X
X
Department of Endocrinology, Wuhan General Hospital of Guangzhou Command, Wuhan 430070, Hubei Province, China. Guangda64@163.tom.com
Qiong-shu
W
W
Wen
J
J
D000328:Adult; D000483:Alleles; D001916:Brachial Artery / Q000502:physiology; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics* / Q000503:physiopathology; D003925:Diabetic Angiopathies / Q000235:genetics* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D052247:Nitric Oxide Synthase Type II / Q000235:genetics*; D011110:Polymorphism, Genetic; D012907:Smoking / Q000009:adverse effects; D014664:Vasodilation / Q000235:genetics* / Q000502:physiology
D052247:Nitric Oxide Synthase Type II