Objective: To investigate the polymorphic distribution of the A1166C, the angiotensin II type I receptor (AT1R) gene, in the Chinese people with essential hypertension (EH), and to study the relationship of A1166C with the TCM syndrome types and the efficacy of hypotensor.
Methods: Blood pressure (BP), body weight index (BWI), fasting blood glucose (FBG), cholesterol (Ch), concentration of triglyceride, levels of serum plasma Ang II , endothelin (ET) and calcitonin-gene related peptide (CGRP) in 206 patients with EH and 86 health subjects of Chinese nationality were determined. DNA of peripheral white blood cells were extracted by salting out method and the polymorphism of AT1R gene A1166C was assessed by PCR and limited enzymatic segmentation. The 206 EH patients were differentiated into different types according to TCM syndrome differentiation, and the gene distribution appeared in each TCM syndromes was compared. Qingxin Capsule (QC) or captopril was used respectively to treat 34 and 32 patients with hypertension of Yin-deficiency and excessive Yang type to observe the relationship between the hypotensive effect of treatment and the distribution of gene types.
Results: (1) No significant difference was found in BWI, FBG, blood lipid or serum related hormones, only the difference in systolic and diastolic pressure was shown between the hypertension group and the control group. (2) The rate of AT1R AC plus CC gene type in EH patients was 0.126, which was significantly higher than that in the normal control group (0.047, P < 0.01). The frequency of C allele distribution was obviously higher than that in the normal control group (0.068 vs 0.023, P<0.05). No significant difference was found in AT1R gene types or frequency of allele distribution between different sexes (male and female). (3) Analysis on relationship between gene types and clinical phenotype showed that no significant difference was found in systolic pressure, diastolic pressure, blood glucose, blood lipid, plasma Ang II, ET, or CGRP between patients with AA gene type and with AA plus CC gene type by t test (P > 0.05). (4) Analysis on relationship between gene type and TCM syndrome type showed that the distribution of AA gene type and AA plus CC type was insignificantly different in patients with various TCM syndrome types. (5) Analysis on relationship between gene type and hypotensive effect of treatments showed that both QC and captopril were effective to patients with hypertension of different gene types. The hypotensive effect of either was similar in spite of what gene types the patients with.
Conclusion: A1166C gene type is related to EH in the Chinese, C allele might a susceptible gene to hypertension, while TCM syndrome type of EH patients might not be related to whether C allele was borne. The hypotensive effect of QC or captopril was not related to whether C1166 allele was borne. No significant difference of blood pressure, blood glucose, blood lipid, plasma Ang II, ET, or CGRP in patients with different gene types, which suggested the effect of gene types on hypertension might not be by path of glucose or lipid metabolism, ET, CGRP or plasma Ang II system.