Correlation Between Angiotensinogen Gene M235t Polymorphism And Essential Hypertension In The Bai Nationality

Background:Essential hypertension(EH), also called hypertensive disease, is the most common cardiovascular disease severely affecting human health, characterized by the high systemic arterial pressure because of some complex undefined causes. EH is considered to the result of the interaction of genetic, environmental and individual factors now. and in its occurrence and development the polygenic variation may play a critical role. By now, more than 150 human hypertension candidate genes have been listed, involved in RAAS, sympathetic nervous system, endothelial function, signal transduction and so on. The renal body fluid pressure control system can regulate the blood volume and long term blood pressure primarily through RAAS. In this system, the plasma concentration of AGT as the precursor of angiotonin and single renin substrate has a close relation with blood pressure, and so the correlation of AGT gene mutation and EH has attracted a widespread attention for a long time. The Bai nationality, highly concentrated in Dali area. Yunnan province in China, has the special affecting factors, which are distinguished from the ones of other nations, including inhabited environment, eating habit, culture atmosphere and so on. This study can offer the important basis for seeking the etiology, prevention and treatment of EH by investigating the correlation between M235T polymorphism of the second ex on of AGT gene and EH in Bai population from Dali area.Objective:Investigating the association between M235T polymorphism of AGT gene and EH in the Bai people living in Dali area.Methods:Collecting the data of 141 cases for the hypertensive(HT) group and 134 people for the normotensive(NT) group in the Bai population according to the inclusion criteria. The body mass index(BMI), fasting serum glucose(FSB), plasma total cholesterol(TC) and triglyceride(TG), low and high density lipoprotein cholesterol(LDL-C & HDL-C). serum creatinine(CR), urea(UR) and uric acid(UA) were measured respectively at the same time of taking blood samples. After the three genotypes of AGT gene M235T polymorphism (TT, MT and MM genotypes) were amplificated by mutagenically separated polymerase chain reaction (MS-PCR), and confirmed by gene sequencing, then some statistical methods was used for the distribution of the three genotypes and two alleles in Bai population from the two groups.Results:There was no significant difference (P>0.05) between HT and NT groups in TT,MT,MM genotypic frequencies(TT genotype:χ2=0.790, P=0.374:MT genotype:χ2=1.181. P=0.277; MM genotype:x2=0.120,P=0.729), and T, M allele frequencies(x2 =0.313, P=0.576); But the TT, MT genotypic frequencies and T allelic frequencies in Bai men showed significant difference between the two groups,(P<0.05); Our experimental results also showed that the diastolic blood pressure(DBP) of the Bai men with TT genotype and women with MT genotype increased significantly by comparing the SBP and DBP between the two sexes(P＜0.01);Comparing HT against NT group, the increased BMI of the Bai men with TT, MT genotype and T allele had statistical significance(P＜0.05 or 0.01); Furthermore, the plasma levels of TC. TG, FSG in the Bai hypertensive population with all the M235T polymorphism, and of UR. CR, UA with all the polymorphism except with MT genotype, were increased remarkably (P＜0.05 or 0.01), but the plasma concentration of HDL-C with MT genotype decreased significantly(P<0.05).Conclusion:(a) In this study, no intimate correlation was found between the M235T polymorphism of AGT gene and the pathogenesy of essential hypertension in the total Bai population, (b) There may be has a correlation between the EH in Bai male population and the polymorphism of TT, MTgenotype and T allele. (c) TT, MT genotypes and T allele may be associated with the BMI of Bai male population, and increase the risk of male obesity hypertension, (d) M235T polymorphism of AGT gene may be an important risk factor of easily causing the coronary artery disease, cerebral infarction, diabetes mellitus and hypertensive renal damage in Bai hypertensive population.