Association of the renin gene polymorphism, three angiotensinogen gene polymorphisms and the haplotypes with essential hypertension in the Mongolian population.

Renin is a rate-limiting enzyme of the renin-angiotensin system and plays a crucial role in the regulation of blood pressure (BP). Angiotensinogen (AGT) is the precursor of potent vasoactive hormone angiotensin II and the AGT gene has been incriminated as a marker for genetic predisposition to essential hypertension (EH) in some ethnic groups. The purpose of the study is to explore the association of a new genetic marker of renin gene, and AGT gene M235T, A-6G, and A-20C polymorphisms and their haplotypes with EH in the Mongolian population. On the basis of the prevalence survey, 243 hypertensives and 258 normotensives who had no blood relationship with each other were selected as subjects. All the subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/ deletion (I/D) polymorphism was genotyped by PCR-polyacrylamide gel electrophoresis. AGT gene M235T, A-6G, and A-20C polymorphisms were genotyped by a PCR-restriction fragment length polymorphism and single-strand conformation polymorphism. The frequencies of renin genotype DD and allele D in hypertensives (36.21%, 63.79%, respectively) were significantly higher than those in normotensives (29.84%, 57.17%, respectively, P < 0.05). The odds ratios (OR) of renin genotype ID, DD to renin genotype II on hypertension were 1.98 (OR 95% CI 1.08-3.72) and 2.51 (OR 95% CI 1.33-4.88), respectively. There were no significant differences in the distributions of genotypes and alleles for AGT gene M235T, A-6G, and A-20C polymorphisms and all different haplotypes between the two groups. Renin gene I/D polymorphism is associated with EH, whereas AGT gene M235T, A-6G, and A-20C polymorphisms and the haplotypes are not associated with EH in the Mongolian population.

Multiple risk factor clustering and risk of hypertension in the Mongolian ethnic population of China.

OBJECTIVE: To evaluate whether the clustering of risk factors, both environmental and genetic, increases the risk of essential hypertension (EH) and the accumulation of risk factors influences the blood pressure level in normotensives. METHODS: On the basis of a prevalence survey, 501 subjects of Mongolian ethnicity (243 hypertensives and 258 normotensives) who were not related to each other were selected to conduct a case-control study. All subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/deletion (I/D) polymorphism, a new genetic marker, was genotyped with PCR and polyacrylamide gel electrophoresis. RESULTS: Overweight, alcohol consumption, and renin gene I/D polymorphism were significant risk factors of EH (P<0.05). The odds ratios (OR) for the number of risk factors were 2.39 (95%CI: 0.98-6.74) for one risk factor, 5.03 (95%CI: 2.06-14.18) for two, and 6.09 (95%CI: 1.85-22.38) for three respectively after adjusting for age and sex. In normotensives, age- and sex-adjusted mean blood pressures increased with more accumulation of risk factors. However, there were no significant differences among the different blood pressure levels according to the number of risk factors (P>0.05). CONCLUSION: Overweight, alcohol consumption, and renin gene I/D polymorphism are risk factors of EH in the Mongolian ethnic population of China. The accumulation of the risk factors causes a sharp increase of the risk of EH.