同型半胱氨酸及亚甲基四氢叶酸还原酶C677T基因多态性与2型糖尿病合并冠心病的关系

目的：探讨我国北方地区糖尿病合并冠心病（DM＋CHD）者同型半胱氨酸（Hcy）特点及其与代谢相关酶亚甲基四氢叶酸还原酶（MTHFR）C677T基因多态性的关系。方法：研究对象均为北方汉族人，包括无血缘关系的70例DM＋CHD患者、71例DM患者和85名健康对照组。应用荧光偏振免疫法测定Hcy水平，应用微粒子酶免分析免疫法测定血浆叶酸、维生素B12浓度，同时测定血脂。应用聚合酶链反应-限制性内切酶片段长度多态性分析MTHFR C677T基因多态性。结果：DM＋CHD组Hcy平均水平（中位数）显著高于DM组和对照组（P〈0．01）。DM＋CHD组叶酸、维生素B12明显低于DM组及正常对照组（P〈0．05）。DM＋CHD组的T等位基因频率明显高于DM组、对照组（P〈0．01）。DM＋CHD组中MTHFR TT基因型Hcy明显高于CT基因型以及CC基因型（P〈0．01）。Logistic回归分析得到高Hcy血症（HHcy）的OR值为4．085（95％CI 1．983～8．415）（P〈0．01）；MTHFR携带T基因的OR值为2．264（95％CI 1．115-4．594）（P〈0．05）。结论：HHcy、MTHFR677携带T基因是我国北方地区汉族人2型DM合并CHD发生的危险因素。

Relationship between homocysteine methylene tetrahydrofolate reductase polymorphism and coronary heart disease in Chinese type 2 diabetes mellitus

Objective：To explore the significance of homocysteine （Hcy）and the gene polymorphisms of methylene tetrahydrofolate reductase （MTHFR） C677T in type 2 diabetes mellitus （DM）with coronary heart disease （CHD） in China.Methods：We selected 70 patients with type 2 DM and CHD,71 type 2 diabetes patients,and 85 controls in Han nationality from northern China.Hcy levels were measured by fluorescence polarization immunoassay and the plasma folate and vitamin B12 levels by microparticle enzyme immunoassay.The gene polymorphisms of the MTHFR C677T were determined by PCR- RFLP assay.Results：The plasma Hcy levels in DM with CHD group were significantly higher than in DM group and control group （P〈0.01）.The levels of plasma folate and Vitamin B12 in DM with CHD group were significantly lower than in.DM group and control group （P〈0.05）.The T allelic frequency of MTHFR in DM and CHD group was significantly higher than that in DM group and controls （P〈0.01）.The homocysteine levels in Tr homozygotes was markedly higher than in CT genotype patients and in CC genotype patients in DM with CHD group （P〈0.01）.Logistic-regression analysis indicated that the OR of hyperhomocysteinemia was 4.085 （95%CI 1.983-8.415）（P〈0.01）.And the OR of MTHFR 677 with T（including MTHFR CT genotype and TT genotype）was 2.264,95%CI（1.115-4.594） （P〈 0.05）.Conclusion：Hyperhomocysteinemia and MTHFR with T allele were the risk factors for DM with CHD in northern Chinese Han population.