Association of the endothelial nitric oxide synthase (ecNOS) gene polymorphism with carotid atherosclerosis in type 2 diabetes.

This study was done to see whether 27-base pair repeats polymorphism in intron 4 of ecNOS gene is associated with carotid atherosclerosis in type 2 diabetic patients. The polymorphism was identified by polymerase chain reaction (PCR). Ultrasound parameters of carotid atherosclerosis were analyzed in relation to the genotype in 210 patients with type 2 diabetes. The ecNOS4a allele was detected in 34 (16.2%) of this study group. With the exception of the plaque count (P = 0.069), all other parameters obtained by ultrasound examination of carotid arteries were significantly correlated with presence of ecNOS4a allele (P < 0.05). As all the measured carotid parameters correlated well each other, we selected the total mean carotid IMT (intima-media thickness) value to be used for this analysis. In the multivariate analysis including several variables such as age, sex, hypertension, LDL cholesterol, waist-hip ratio, and fasting insulin, all determined to be significant by univariate analysis, ecNOS4a allele had a significant correlation with total mean IMT (P < 0.001). In conclusion, the ecNOS4a allele is associated with carotid atherosclerosis in type 2 diabetic patients in Korea.