Association Study Of The Catechol O-methyltransferase Val 108/158 Met Polymorphism With Essential Hypertension And Carotid Intima-media Thickness

Objective:To investigate the association of the catechol O-methyltransferase Val 108/158 Met polymorphism with essential hypertension and carotid intima-media thickness (IMT) in Chinese population.Methods:A total of 215 hypertensive patients and 227 healthy volunteers were enrolled for the COMT Val 108/158 Met polymorphism genotyping in this study. The concentrations of fasting plasma glucose (FPG), total cholesterol (TC), triglyceride (TG), high-density lipoprotein-cholesterol (HDL-c),low-density lipoprotein-cholesterol (LDL-c),blood urea nitrogen(BUN),creatinine(CREA), uric acid (UA), alanine aminotransferase (ALT),total protein,albumin, globulin, carbamideand and other clinical physique test were determined.The genotypes of COMT in all subjects were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Moreover, carotid ultrasound examinations of the common carotid artery, bulb, and internal carotid artery were performed bilaterally using B-mode ultrasound in 94 hypertensive patients.Subjects were studied for the common carotid diameter in both systolic and diastolic periods, mean IMT of the anterior and posterior wall and plaque.Results:1.There were no significant differences in the genotypic and allelic frequency distribution of the COMT gene Val 108/158 Met polymorphism between hypertensive patients and control subjects (P>0.05).2.Carriers of COMT gene Met in health volunteers had significantly higher waist circumference,WHR, SBP, FPG and LDL-c values than Val genotyped individuals (P<0.05,P<0.01 P<0.05,P<0.05, P<0.05,respectively),and patients with COMT gene Met had higher waist circumference,WHR,FPG, TC,HDL-c and LDL-c(P<0.01, P<0.01,P<0.05,P<0.05,P<0.05,P<0.05,respectively) in hypertensive group than those in Val carriers.3.After gender stratification, there was no significant difference between the male and female hypertensive patients and controls (P>0.05).4.After risk stratification of hypertension, we found no significant difference between the low risk, middle risk, high risk and very high risk groups (P>0.05).5.The results showed that raised body mass index, blood glucose and LDL-c,and hypertension family history were risk factors for hypertension by logistic regression analysis; while COMT Val 108/158 Met polymorphism had no effect on the occurrence of hypertension.6.COMT Val 108/158 Met polymorphism was significantly related to carotid IMT in patients with essential hypertension; the left CCA-IMT and the incidence of IMT thickening was significantly increased in patients carrying Met allele (P<0.05).7.The results showed that Met allele was risk factor for carotid IMT thickening in patients with hypertension by logistic regression analysis.Conclusion:1.The results suggested that there is no relationship between the COMT Val 108/158 Met polymorphism and the susceptibility of essential hypertension.2.The results remain negtive after gender stratification and hypertension risk stratification was done.3.COMT Val 108/158 Met polymorphism was significantly related to the left CCA-IMT and the incidence of IMT thickening in patients with essential hypertension;subjects with mutated COMT polymorphism showed serious arteriosclerosis than wildtype hypertensives(P<0.05).