Angiotensinogen Met235Thr polymorphism, angiotensin-converting enzyme inhibitor therapy, and the risk of nonfatal stroke or myocardial infarction in hypertensive patients

The ThrThr genotype of the angiotensinogen (AGT) Met235Thr polymorphism has been associated with elevated AGT levels, hypertension, increased heart disease risk, and improved blood pressure (BP) response to angiotensin-converting enzyme (ACE) inhibitors. We hypothesized that risk of stroke or myocardial infarction (MI) associated with ACE inhibitor use varies by AGT genotype, with a larger protective effect of ACE inhibitors in individuals with the ThrThr genotype than individuals who are carriers of the Met allele. METHODS: We conducted a population-based case-control study. Participants were health maintenance organization members aged 30 to 79 years with treated hypertension. Those who survived incident stroke (n = 116) or MI (n = 208) during the study period were designated as cases. Control subjects (n = 717) were randomly sampled and frequency-matched to MI cases on age, sex, and calendar year. Health history, medication use, and AGT genotype were assessed. RESULTS: ThrThr genotype was present in 21% of stroke cases, 26% of MI cases, and 19% of control subjects. Compared with nonuse, ACE inhibitor use was associated with lower stroke risk among Thr homozygotes (odds ratio [OR] = 0.37, 95% CI = 0.14 to 0.99) than among Met carriers (OR = 1.4, 95% CI = 0.88 to 2.4; P for interaction =.02). Compared with nonuse, ACE inhibitor use was associated with similar MI risk among Thr homozygotes (OR = 0.90, 95% CI = 0.62 to 1.3) and among Met carriers (OR = 1.2, 95% CI = 0.60 to 2.5; P for interaction = 0.5). CONCLUSIONS: In this hypertensive population, the association of ACE inhibitor use with risk of nonfatal stroke varied by genotype. The protective association between ACE inhibitor use and nonfatal stroke risk among individuals with ThrThr genotype was not observed for nonfatal MI.     

Polymorphisms of renin-angiotensin system in essential hypertension in Chinese Tibetans

Objective To evaluate the potential implications of the genetic variability of angiotensin converting enzyme, angiotensinogen and angiotensin Ⅱ type 1 receptor gene for essential hypertension in Tibetan. Methods A case-control study was conducted in 173 hypertensive individuals and 193 individuals with normal blood pressure. Multiple logistic regression analyses were used to estimate the risks of developing hypertension for different genotypes, and haplotype analyses of the angiotensinogen gene were used to determine the association between two-locus angiotensinogen gene polymorphisms and hypertension. Results As to the risk to high blood pressure and high systolic pressure, women with MM genotype were 7.7 (95% CI: 1.3-20.5) and 8.7 (95% CI: 1.8-20A) times higher than those with “IF genotype after adjustment for age and body mass index. Haplotype frequencies for M235T and G-6A were significantly different between hypertensive individuals and controls, which indicated an association of angiotensinogen gene haplotypes with hypertension, and a significant association of 235T/-6A haplotype with hypotensive effect. Condusion Our results suggest that angiotensinogen gene 235MM is a predictor for hypertension development in Tibetan women but not in men, and may exert its hypertensive effect on linkage disequilibrum with a possible function locus of G-6A.     

抑郁症患者ACE和AGT基因多态性研究

目的 探讨血管紧张素转换酶（ACE）基因插入或缺失（I/D）多态性与血管紧张素原（AGT）基因M235T多态性和抑郁症之间的关联.方法 运用聚合酶链反应结合限制性片段长度多态性检测技术（RFLP-PCR）检测150例抑郁症患者（研究组）和180例健康体检者（对照组）的ACE I/D、AGT M235T等位基因频率和基因型.同时用酶联免疫吸附法（ELISA）检测两组患者的血浆ACE含量.结果 研究组和对照组的ACE I/D位点等位基因频率和基因型差异均有统计学意义（P＜0.05）,DD基因型的抑郁症患病风险升高（OR=2.06,95%CI：1.29～3.85）.对照组血浆ACE含量明显低于研究组,II、ID、DD基因型的血浆ACE含量不同,以DD基因型的ACE含量最高.差异均有统计学意义（均P＜0.05）.两组间AGT M235T等位基因频率和基因型的差异无统计学意义（P＞0.05）.结论 ACE基因I/D多态性和抑郁症有关,DD基因型个体的抑郁症患病风险增高.