脑血管病患者高同型半胱氨酸血症发生机制的初步研究

Preliminary Study on the Mechanism of Hyperhomocysteinemia in Cerebrovascular Disease Patients

目的探讨脑血管病患者高同型半胱氨酸(Hcy)血症的发生机制。方法分别检测脑血管病患者和健康对照者血清Hcy、叶酸和维生素B12水平。应用TaqMan实时PCR技术检测各组MTHFR C677T基因多态性。结果脑血管病组血清Hcy水平显著高于对照组(P<0.01),其中脑梗死组的血清Hcy水平明显高于脑出血组(P<0.01)。与之相反,脑血管病组的血清叶酸和维生素B12水平明显低于对照组(P<0.01)。相关分析结果显示,脑血管病组的血清叶酸和维生素B12水平与Hcy水平呈负相关(r1=-0.80,r2=-0.83)。脑血管病组MTHFR C677T基因型分布和T等位基因频率与对照组比较有统计学差异(P<0.05)。各组MTHFR C677T的TT型血清Hcy水平明显高于CT型和CC型(P<0.01)。但CT型和CC型的血清Hcy水平比较无统计学差异(P>0.05)。结论高Hcy血症是导致脑血管病发生的危险因素。MTHFR C677T基因突变及低水平的叶酸和维生素B12是引起血清Hcy水平升高的遗传和营养因素。

Objective To investigate the mechanism of hyperhomocysteinemia in cerebrovascular disease patients. Methods Serum Hcy level was measured by enzyme method. Auto chemiluminescence immunoassay （CLIA） was applied for detecting serum folate and vitamin B12 levels in all groups. The gene polymorphism of MTHFR C677T of patients with cerebral infarction （CI）,cerebral hemorrhage （CH） and healthy controls were analyzed by a TaqMan real-time PCR technology. Results Serum Hcy levels in cerebrovascular disease group were significantly higher than that of control group （P 〈 0.01 ）. Moreover,serum Hcy levels in CI group were obviously higher than that of CH group （P 〈 0.01）. In contrast,serum folate and VitB12 levels in cerebrovascular diseases group were obviously lower than that of control group （P 〈 0.01 ）. Meanwhile,correlation analysis results showed that serum folate and VitB12 levels were negatively correlated with serum Hcy levels in cerebrovascular diseases group （r1=-0.80, r2=-0.83 ）. The genotype distribution of MTHFR C677T and the frequency of T allde had significant differences between cerebrovascular diseases group and control group （P 〈 0.05）. Serum Hcy levels in TF genotype of MTHFR C677T were obviously higher than that of CT and CC genotype in all groups （P 〈 0.01 ）. But there were no significant difference of serum Hcy levels between CT and CC genotype （P 〉 0.05 ）. Conclusion Hyperhomocysteinemia was a risk factor resulting in occurrence of cerebrovascular diseases. The mutation of MTHFR C677T and low levels of serum folate and VitB12 were genetic and nutritional factors elevating the level of serum Hcy.