Li Jun, Li Bin, Qi Juanfei, Shen Bo
Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province, Taizhou 317000, China.
Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province, Taizhou 317000, China; Email:
Zhonghua Xin Xue Guan Bing Za Zhi. 2015 Jun;43(6):554-61.
To evaluate the effects of folic acid, vitamin B(6) and B(12) supplementation on plasma homocysteine level and risk of cardiovascular disease.
The databases, including Embase, Pubmed, Ovid, Biosis, China National Knowledge Infra-structure (CNKI), Wanfang Data, VIP Database for Chinese Technical Periodical (VIP), Chinese Biomedical Literature Database (CMB), were searched to identify random control trials between February 1994 to February 2014 on the effect of folic acid, vitamin B(6) and B(12) supplementation on plasma homocysteine level and risk of cardiovascular disease. The screening, data extraction and quality assessment were conducted in accordance with the inclusion and exclusion criteria by two reviewers independently. The software Review Manager 5.2 was used. Funnel plots and Egger's regression test were applied to evaluate the publication bias.
Data from 12 studies including 34 481 patients were analyzed using a fixed-effects model. Funnel plot and Egger's test (P > 0.10) confirmed the absence of publication bias. No statistically significant heterogeneity was detected on testing after excluding the sources of heterogeneity (chi-square test, I < 2 < 50%). Baseline homocysteine levels were similar between the placebo and folic acid, vitamin B(6) and B(12) groups (all P > 0.05). Mean homocysteine levels were significantly lower with folic acid, vitamin B(6) and B(12) therapy compared with placebo during follow-up (all P < 0.05). The pooled relative risks with 95% confidence intervals of outcomes for patients treated with folic acid, vitamin B(6) and B(12) supplementation compared with placebo were 0.98 (0.93-1.03) for cardiovascular event, 0.97 (0.87-1.07) for coronary artery disease, 1.00 (0.92-1.08) for myocardial infarction and 0.92 (0.82-1.03) for cardiovascular death.
Folic aicd combined with vitamin B(6) and B(12) treatment significantly reduced plasma homocysteine level, but did not affect the risk of cardiovascular disease. Thus, folic acid combined with vitamin B(6) and B(12) should not be recommended as secondary prevention of cardiovascular diseases.
评估补充叶酸、维生素B6和B12对血浆同型半胱氨酸水平及心血管疾病风险的影响。
检索Embase、Pubmed、Ovid、Biosis、中国知网（CNKI）、万方数据、维普中文科技期刊数据库（VIP）、中国生物医学文献数据库（CMB）等数据库，以识别1994年2月至2014年2月间关于补充叶酸、维生素B6和B12对血浆同型半胱氨酸水平及心血管疾病风险影响的随机对照试验。由两名研究者独立按照纳入和排除标准进行筛选、数据提取及质量评估。使用RevMan 5.2软件。采用漏斗图和Egger回归检验评估发表偏倚。
采用固定效应模型分析了包括34481例患者的12项研究的数据。漏斗图和Egger检验（P>0.10）证实不存在发表偏倚。排除异质性来源后进行检验，未检测到具有统计学意义的异质性（卡方检验，I²<50%）。安慰剂组与叶酸、维生素B6和B12组的基线同型半胱氨酸水平相似（均P>0.05）。随访期间，叶酸、维生素B6和B12治疗组的平均同型半胱氨酸水平显著低于安慰剂组（均P<0.05）。与安慰剂相比，补充叶酸、维生素B6和B12治疗的患者结局的合并相对风险及95%置信区间为：心血管事件0.98（0.93 - 1.03），冠状动脉疾病0.97（0.87 - 1.07），心肌梗死1.00（0.92 - 1.08），心血管死亡0.92（0.82 - 1.03）。
叶酸联合维生素B6和B12治疗可显著降低血浆同型半胱氨酸水平，但不影响心血管疾病风险。因此，不建议将叶酸联合维生素B6和B12用于心血管疾病的二级预防。
