Effect of folic acid supplementation on risk of cardiovascular diseases - A meta-analysis of randomized controlled trials
Effect of folic acid supplementation on risk of cardiovascular diseases - A meta-analysis of randomized controlled trials
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DOI：
10.1001/jama.296.22.2720
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发表时间：
2006-12-13
影响因子：
120.7
通讯作者：
He, Jiang
中科院分区：
文献类型：
--
作者：
Bazzano, Lydia A.;Reynolds, Kristi;He, Jiang
背景
流行病学研究表明，叶酸摄入可降低心血管疾病风险。然而，迄今为止关于膳食补充叶酸的随机对照试验结果并不一致。
目的
在已有心血管或肾脏疾病的人群中，评估随机对照试验中叶酸补充对心血管疾病风险和全因死亡率的影响。
数据来源
通过检索MEDLINE（1966年1月 - 2006年7月）获取研究资料，使用的医学主题词包括心血管疾病、冠心病、冠状动脉血栓形成、心肌缺血、冠状动脉狭窄、冠状动脉再狭窄、脑血管意外、随机对照试验、临床试验、高叶酸、叶酸，以及文本词叶酸和叶酸盐。还检索了所有检索到的文章的参考文献，并联系了该领域的专家。
研究选择
从165篇相关检索报告中，12项随机对照试验比较了叶酸补充与安慰剂或常规治疗，试验最短持续时间为6个月，并以临床心血管疾病事件作为终点进行报告。
数据提取
2名研究者使用标准化方案独立提取关于研究设计、参与者特征、同型半胱氨酸水平变化以及心血管疾病结局的数据。
数据综合
使用随机效应模型对包含16958名已有血管疾病参与者数据的研究进行分析。与对照组相比，接受叶酸补充治疗的患者的结局总体相对风险（95%置信区间）为：心血管疾病0.95（0.88 - 1.03），冠心病1.04（0.92 - 1.17），中风0.86（0.71 - 1.04），全因死亡率0.96（0.88 - 1.04）。在已有心血管或肾脏疾病的参与者中，相对风险是一致的。
结论
在有血管疾病既往史的参与者中，叶酸补充未显示可降低心血管疾病风险或全因死亡率。一些正在进行的大样本量试验可能会对这一重要的临床和公共卫生问题提供明确的答案。
Context Epidemiologic studies have suggested that folate intake decreases risk of cardiovascular diseases. However, the results of randomized controlled trials on dietary supplementation with folic acid to date have been inconsistent.Objective To evaluate the effects of folic acid supplementation on risk of cardiovascular diseases and all-cause mortality in randomized controlled trials among persons with preexisting cardiovascular or renal disease.Data Sources Studies were retrieved by searching MEDLINE ( January 1966-July 2006) using the Medical Subject Headings cardiovascular disease, coronary disease, coronary thrombosis, myocardial ischemia, coronary stenosis, coronary restenosis, cerebrovascular accident, randomized controlled trial, clinical trials, homofolic acid, and folic acid, and the text words folic acid and folate. Bibliographies of all retrieved articles were also searched, and experts in the field were contacted.Study Selection From 165 relevant retrieved reports, 12 randomized controlled trials compared folic acid supplementation with either placebo or usual care for a minimum duration of 6 months and with clinical cardiovascular disease events reported as an end point.Data Extraction Data on study design, characteristics of participants, changes in homocysteine levels, and cardiovascular disease outcomes were independently abstracted by 2 investigators using a standardized protocol. Data Synthesis Studies including data from 16 958 participants with preexisting vascular disease were analyzed using a random-effects model. The overall relative risks (95% confidence intervals) of outcomes for patients treated with folic acid supplementation compared with controls were 0.95 (0.88-1.03) for cardiovascular diseases, 1.04 (0.92-1.17) for coronary heart disease, 0.86 (0.71-1.04) for stroke, and 0.96 (0.88-1.04) for all-cause mortality. The relative risk was consistent among participants with preexisting cardiovascular or renal disease.Conclusions Folic acid supplementation has not been shown to reduce risk of cardiovascular diseases or all-cause mortality among participants with prior history of vascular disease. Several ongoing trials with large sample sizes might provide a definitive answer to this important clinical and public health question.