B族维生素干预对高同型半胱氨酸血症脑梗死患者二级预防的作用

Effect of B vitamin therapy on prevention of recurrent stroke in ischemic stroke patients with hyperhomocysteinemia

目的评价联合应用B族维生素对高同型半胱氨酸血症（hyperhomocysteinemia，Hhcy）脑梗死症状与非症状复发的二级预防作用。方法采取前瞻、开放、平行对照研究方法，将1000例Hhcy脑梗死患者分为B族维生素干预组500例（每日口服叶酸2．5mg、维生素B，2500μg、维生素瞰25mg）和对照组500例，随访2年观察B族维生素联合应用对脑梗死症状性复发与影像学再发的二级预防作用，记录试验期间血浆总同型半胱氨酸（total homocysteine，tHcy）水平。结果B族维生素干预可显著降低患者血浆tHcy水平，干预3个月后干预组tHcy较基线下降14．7％，随访2年时下降19．2％，与对照组比较差异有统计学意义（F=94．39，P〈0．05）。症状性脑梗死复发率干预组13．6％（68／500）、对照组14．0％（70／500，RR=0．99，95％C／0．68—1．42）；无症状性影像学脑梗死复发率干预组与对照组均为4．8％（24／500，RR=1．11，95％C／0．62～2．02）；总计脑梗死复发干预组18．4％（92／500）、对照组18．8％（94／500，RR=0．96，95％C／0．73～1．26），组间差异均无统计学意义。结论本研究结果未能证实B族维生素干预Hhcy对脑梗死症状性与非症状性复发二级预防有益。

Objective To investigate whether the B vitamins supplements would lower total homocysteine and reduce the risk of recurrent stroke in patients with recent ischemic stroke. Methods A prospective, open, case-controlled clinical trial. One thousand ischemic stroke patients with hyperhomocysteinemia were followed up. They were assigned to receive either a daily close of B vitamins （folic acid 2. 5 mg, B6 25 mg, Bt2 500 I^g, treatment group, n =500） or not （control group, n =500） for a period of 2 years. Total homocysteine level, demographic information and traditional risk factors were collected as well as recurrent cerebral infarction were noted. Results Homocysteine levels were significantly reduced in the active treatment group, reduction of total homocysteine was 14. 7% at 3 months and 19. 2% at 24 months （ F = 94. 39, P 〈 0. 05 ）. The risk of ischemic recurrent stroke with clinical sign within 2 years was 13.6% for the active treatment group and 14. 0% for the control group （risk ratio = 0. 99, 95% CI 0. 68-1.42）. The risk of recurrent stroke with only MRI or CT brain scan evidence was 4. 8% for both groups （risk ratio = 1.11, 95% CI 0.62-2.02）. The risk of total recurrent stroke was 18.4% for the treatment group and 18.8% for the control group （ risk ratio = 0. 96; 95% CI 0. 73-1.26）, but these effects were not significant. Conclusion A significant benefit of secondary prevention with long-term reductions in blood homocysteine levels with B vitamins supplementationin during the 2 years of follow-up is not yet proven.