Relationship Between Methylation Of 11β - Steroid Dehydrogenase 2 Promoter Region And Plasma Renin In Patients With Essential Hypertension

Part1 Detection of plasma renin activity in primary hypertension patientsObjective To explore the change of plasma renin activity in patients suffering from primary hypertension and the proportion of low-renin hypertension in all cases of primary hypertension.Methods 246 untreated cases of primary hypertension were choosed from my in-patient department as the hypertension group, and 220 cases of physically healthy volunteers were as the control group. Plasma renin activities were measured using Elisa method respectively. To compare the differences between the two groups and analyze the differences across groups with different blood pressures, ages, and Body Mass Index（BMI）. The patients were divided into different groups based on their plasma renin activity level, and analyze the proportion of low-renin hypertension in all cases of primary hypertension.Results The hypertension group observes higher plasma rein activity than the control group and the difference is statistically significant（p<0.01）. The differences in plasma renin activities across groups with different blood pressures, ages, and BMI are not statistically significant（P>0.05）. Patients suffering from low-renin hypertension make up 39.4% of the total number of patients with primary hypertension.Conclusion The hypertension group has higher plasma renin activity than the control group. Plasma renin activity is irrelevant with differences in blood pressure. Low-renin hypertension has larger proportion in primary hypertension patients. Low renin hypertension is an important sub-type of primary hypertension.Part2 Measurement of methylation rate of 11β-hydroxysteroid dehydrogenase-2 promoter in cases of primary hypertension, and the relationship between methylation rate of 11β-HSD2 promoter and low-renin hypertensionObjective To measure methylation rate of 11β-hydroxysteroid dehydrogenase-2（11β-HSD2） promoter in cases suffering from primary hypertension, and explore the relationship between methylation rate of 11β-hydroxysteroid dehydrogenase-2 promoter promoter and low rein hypertension.Methods Sequenom Mass ARRAY method was used to detect the methylation rate of 11β-hydroxysteroid dehydrogenase-2 promoter（-101-461） in cases suffering from primary hypertension. To select 194 cases of successful measurement and 200 cases of physically healthy volunteers as the hypertension group and control group respectively and compare the differences in the rate of methylation in the two groups and analyze relationship between methylation rate of 11β-HSD2 promoter and low renin hypertension.Results The hypertension group observes higher methylation rate than the control group and the difference is statistically significant（P<0.05）. The methylation rate are higher at Cp G₇、8（-20 to-14）;Cp G₉（-8 to-9）;Cp G₆2、63、64（373 to 378）; Cp G₆5（390 to 391）;Cp G₇2（430 to 431）in primary hypertension patients and the differances are significant（P<0.05）. Cp G₇、8 and Cp G₉ are in the core promoter sequence. The differences of methylation rate at Cp G₇、8 、Cp G₉ between patients with low, medium, and high renin group are statistically significant（p<0.05）. There is an observable increase in the number of patients with low-rein hypertension among the group with a methylation rate of 30%-45% at Cp G₇、8 、Cp G₉, and the difference has statistical significanc（P<0.05）.Conclusion The methylation of 11β-HSD2 promoter participate the onset of primarty hypertension. There is a close relationship between the higher methylation rate of 11β-HSD2 core promoter and low-renin hypertension.