2型糖尿病颈动脉内中膜厚度与亚甲基四氢叶酸还原酶基因C677T多态性及血浆同型半胱氨酸水平的关系

The relationship of carotid intima-media thickness with C677T polymorphism of MTHFR and plasma homocysteinc level in type 2 diabetes

目的探讨亚甲基四氢叶酸还原酶(MTHFR)基因C677T多态性及同型半胱氨酸水平与早期2型糖尿病(T2DM)颈动脉内中膜厚度(IMT)的关系及影响因素。方法测定T2DM患者及对照组(NC)颈动脉IMT,分为糖尿病无内中膜增厚组(DM1)和糖尿病合并内中膜增厚组(DM2)。用PCR-RFLP检测MTHFR基因C677T多态性。结果 DM2组MTHFR C677T基因TT基因型频率与NC组比较明显增高(40.4% vs 17.3%,P<0.01),与DM1组比较明显增高(40.4% vs 17.9%,P<0.01),DM1组与NC组比较无统计学差异(17.9% vs 17.3%,P>0.05)。T等位基因频率DM2组与NC组比较明显增高(57.0% vs 33.7%,P<0.01),与DM1组比较明显增高(57.0% vs 42.9%,P<0.01),差异有统计学意义。结论高同型半胱氨酸血症、T等位基因是早期糖尿病患者颈动脉内中膜增厚的危险因素之一,血浆同型半胱氨酸水平与MTHFR C677T基因多态性有关。

Objective To investigate the relationship of carotid intima-media thickness with C677T polymorphism of MTHFR and plasma homocysteine level in type 2 diabetes Methods The 226 T2DM cases were divided into two groups according to the IMT： normal （DM1）and thicked IMT （DMz）. Plasma concentration of total Hcy was measured by direct chemiluminescence. Genetic C677T polymorphism of MTHFR was examined by polymerase chain reaction restriction fragment length polymorphisms （PCR-RFLP）. Carotid IMT was determined by the use of the Doppler ultrasonography. Results The frequency of TT genotype in DM2 was significantly higher than that in NC group （40. 4% vs 17.3%, P=0. 003）, the frequency of TT genotype in DM2 group was significantly higher than that in DM1 group （40.4 % vs 17.9 %, P=0.001）. Similarly, the frequency of T allele in DM2 group was significantly higher than that in NC and DM1 group （57.0% vs 33.7%vs 42.9%, P〈0.01）. Conclusions Hyperhomocysteinemia and T allele seems to be the risk factors of early atherosclerosis in patients with type 2 diabetes. Mutation in MTHFR is associated with elevated plasma levels of Hcy.