亚甲基四氢叶酸还原酶C677T基因多态性与原发性高血压患者颈动脉粥样斑块形成的相关性研究

Association between methylenetetrahydrofolate reductase gene(C677T) polymorphisms and carotid atherosclerotic plaque in patients with essential hypertension

目的研究同型半胱氨酸代谢关键酶亚甲基四氢叶酸还原酶(MTHFR)C677T基因多态性与原发性高血压患者颈动脉粥样硬化斑块形成的相关关系。方法选取原发性高血压患者210例,应用彩色超声仪进行颈动脉检查,其中斑块组120例,无斑块组90例;应用聚合酶链反应检测其MTHFR C677T基因多态性,用酶联免疫吸附法测定血浆同型半胱氨酸水平,用SPSS 17.0统计软件进行数据分析,计量资料两组比较采用t检验,多组间比较采用单因素方差分析,计数资料采用χ2检验。结果斑块组MTHFR TT基因型频率及T等位基因频率与无斑块组比较明显升高(26.6%vs.12.2%,χ2=6.618,P<0.05;47.1%vs.37.2%,χ2=4.084,P<0.05)。斑块组血浆同型半胱氨酸水平明显高于无斑块组[(12.42±3.68)μmol/L vs.(9.74±3.56)μmol/L,t=5.296,P<0.05]。斑块组高血压患者TT基因型的同型半胱氨酸水平[(14.25±3.82)μmol/L]显著高于CT型[(12.1±3.36)μmol/L]和CC型[(11.3±2.87)μmol/L](F=7.21,P<0.05),无斑块组高血压患者TT基因型的同型半胱氨酸水平[(12.89±4.45)μmol/L]显著高于CT型[(9.52±3.15)μmol/L]和CC型[(9.01±3.27)μmol/L](F=5.70,P<0.05)。结论 MTHFR C677T基因多态性可能与高血压患者颈动脉粥样斑块形成有关,位点C677→T基因突变可能通过高同型半胱氨酸血症促进动脉粥样硬化的发展。

Objective The C677 T variants of methylenetetrahydrofolate reductase gene(MTHFR) have been shown to influence homocysteine metabolisms. The aim of our study was to evaluate the association between MTHFR(C677T) polymorphisms and carotid atherosclerotic plaque in patients with essential hypertension. Methods The intima-media thickness(IMT) of carotid artery and the presence of atherosclerotic plaques were determined by B-mode ultrasoundgraphy in 210 patients with hypertension. The plasma total homocysteine(t Hcy) level was measured by enzyme linked immunoassay and MTHFR(C677T) genotype was detected by polymerase chain reaction. A total of 210 patients with hypertension were assigned to either plaque group or non-plaque group. Results The frequency of TT genetype and 677 T allele were higher in plaque group patients than non-plaque group(26.6% vs. 12.2%, χ2=6.618, P<0.05; 47.1% vs. 37.2%, χ2=4.084, P<0.05). The plasma t Hcy level was significantly higher in plaque group than in non-plaque group,(12.42±3.68)μmol/L vs.(9.74±3.56)μmol/L(t=5.296 P<0.05). The plasma t Hcy levels in plaque group patients with TT genetype were significantly higher than patients with CT and CC genetype,(14.25±3.82)μmol/L vs.(12.1±3.36)μmol/L vs.(11.3±2.87)μmol/L(F=7.21, 5.70; P<0.05). The plasma t Hcy levels in non-plaque group patients with TT genetype were significantly higher than patients with CT and CC genetype,(12.89±4.45)μmol/L vs.(9.52±3.15)μmol/L vs.(9.01±3.27)μmol/L(F=5.70; P<0.05). Conclusions The results show that C677 T TT genotype is consistently associated with a higher t Hcy in patients with hypertension. MTHFR variants might be linked to carotid atherosclerotic plaque in patients with essential hypertension by involvement of the regulation of homocysteine activity.