The Relationship Between Gene Polymorphism Of Angiotensin Ⅱ Type 1 Receptor A1166C And Essential Hypertension

Object To investigate the relationship between polymorphism of angiotensin Ⅱ type 1 receptor (AT1R) gene and essential hypertension (EH), and the association between the AT1R gene polymorphism and plasm lipid level and LVMI (left ventricular mass index ) were also studied. Methods The studied objects were born in DaLian city and lived in DaLian for more than ten years. 328 EH patients (enrolled the department of cardiology, the second affiliated hospital of Dalian medical university) are EH group, with 571 healthy people as control group. Blood pressure, body mass index, fasting serum total cholesterol, triglyceride, high-density lipoprotein cholesterol, ApoA, ApoB were measured in all subjects. Interventricular septal thickness (IVST), left ventricular end-diastolic diameter (LVEDD), and left ventricular posterior wall thickness (LVPWT) were measured by echocardiogram in EH patients. Left ventricular mass index (LVMI) was calculated by Devereux formula. Genomic DNA was extracted from peripheral blood leukocytes by phenol/chloroform method. Polymerase chain reaction combined with restriction enzyme digestion was used to determine the polymorphism of the 1166 site of AT1R gene. PCR products were digested by Dde Ⅰrestriction enzyme and visualized on ethidium bromide-stained 2% agarose gels through UV Transilluminator. The experimental data were analyzed with SPSS11.5 software. One-way ANOVA was used to test differences of clinical data between groups. Analyze the frequencies of AA/AC genotypes and 1166C allele of AT1R gene between EH and control group by Chi-square test. Logistic regression analyses were performed with the aim of evaluating the risk factors of essential hypertension. Multiple linear regression was used to analyze the linear relation between the clinical data and LVMI.Results Two genotypes were detected (AA and AC) in our study. The frequencies of AC genotype and C1166 allele of AT1R gene of EH patients were higher than that of control (AC: 0.228 vs 0.107, p=0.001; C: 0.114 vs 0.053, p=0.001); The frequency of AC genotype was higher than that of control in male EH group (0.239 vs 0.086, p< 0.001), OR = 3.49, 95%CI (1.226-5.899). The frequencies of AC genotype and C1166 allele of AT1R gene of female EH patients were higher than that of control, but there was no statistical significance. The frequencies of AC genotype for male EH patients in three age groups (≤40, 41-60, and>60 years) were higher than that of control (0.176 vs 0.053, p= 0.049; 0.250 vs 0.139, p= 0.045; 0.243 vs 0.000, p= 0.012). There were no significant differences in female groups (0.125 vs 0.023, p= 0.058; 0.187 vs 0.181, p= 0.917; 0.268 vs 0.125, p= 0.101). There was no significant difference of plasma lipid levels between AA and AC genotype. Although LVMI, BMI, SBP, DBP in AA genotype were higher than that of AC genotype in EH group, there was no statistical significance. Logistic regression analysis showed that age, gender, family history of EH were independent risk factors of EH. Polymorphism of the gene failed to enter the model. There was linear relation between SBP and LVMI. Conclusion A1166C polymorphism of AT1R gene was related with EH and C1166 allele of AT1R gene may play a role in essential hypertension in males. However, it is not an independent risk factor. There was no association between AT1R gene polymorphism and LVMI. The contribution of AT1R gene to the development of EH was independent of plasma lipid levels.