B族维生素干预血浆同型半胱氨酸水平防治心脑血管疾病作用的Meta分析

Effect of B Vitamins Supplementation on Cardiovascular and Cerebrovascular Disease by Lowering Plasma Homocysteine Concentration:A Meta-analysis

目的评价通过补充B族维生素降低血浆同型半胱氨酸(Hcy)水平对心脑血管疾病的防治作用。方法以"homocysteine"、"cardiovascular disease"、"cerebrovascular disease"、"Bvitamins"、"randomized controlled trial"等为检索词,检索PubMed、Ovid、Springer等电子数据库;并同时运用手工检索和文献追溯手段,收集国外1998～2008年6月公开发表的关于补充B族维生素干预血浆同型半胱氨酸水平的随机对照试验。两名评价者独立依据纳入和排除标准筛选文献,提取资料并进行方法学质量评估。统计学分析采用RevMan4.2软件。结果共纳入16个随机对照试验(共27043例)。Meta分析结果表明,干预组与对照组之间心血管事件(CVE)、冠心病(CHD)、脑卒中和总病死率的差异均无统计学意义,其RR(95%CI)分别为0.98(0.94,1.03)、0.99(0.92,1.07)、0.90(0.80,1.02)、0.98(0.92,1.05)。剔除评分较低的研究后做敏感性分析,结果不变。结论①目前的研究尚未能证实同型半胱氨酸和心脑血管疾病之间存在因果关系,尚需大量大规模的前瞻性随机对照试验来验证。②目前还没有足够证据说明补充B族维生素会减少心血管事件发生的危险,故不推荐把补充B族维生素作为心脑血管疾病的二级预防措施。

Objective To assess the effect of B vitamins supplementation on cardiovascular and cerebrovascular diseases, and also to evaluate the relationship between homocysteine and risk of cardiovascular and cerebrovascular diseases. Methods Using the words ‘homocysteine＇, ‘cardiovascular disease＇, ‘cerebrovascular disease＇, ‘B vitamins＇, and ‘randomized controlled trial＇, we searched PubMed, Ovid, and Springer. We also hand searched relevant journals and conference proceedings. Randomized controlled trials published between 1998 and luly 2008 which evaluated the effect of B vitamins supplementation on vascular diseases were collected. Two reviewers independently screened trials, extracted data, and evaluated the quality of included trials. The Cochrane Collaboration＇s RevMan 4.2 software was used for statistical analysis. Results Sixteen trials involving 27,043 patients with vascular disease were included. Results of meta-analyses showed that no significant differences were identified between the B vitamins group and the control group for each of the four endpoints, including the risk of cardiovascular events （RR 0.98, 95%CI 0.94 to 1.03）, the risk of coronary heart disease （RR 0.99, 95%CI 0.92 to 1.07）, the risk of stroke （RR 0.90, 95%CI 0.80 to 1.02）, and the total mortality （RR 0.98, 95%CI 0.92 to 1.05）. Sensitivity analyses conducted by a random effect model or with the exclusion of low-quality trials did not change the overall results. Conclusion The trials currently available cannot confirm the causal relationship between homocysteine and risk of cardiovascular and cerebrovascular diseases. More evidence from large-scale randomized controlled trials is needed to confirm this. There is not sufficient evidence to show that B vitamins supplementation can lower the risk of cardiovascular and cerebrovascular diseases. B vitamins supplementation should not be recommended for the secondary prevention of such diseases.