Wang Xiaobin, Qin Xianhui, Demirtas Hakan, Li Jianping, Mao Guangyun, Huo Yong, Sun Ningling, Liu Lisheng, Xu Xiping
Mary Ann and J Milburn Smith Child Health Research Program, Children's Memorial Hospital and Children's Memorial Research Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Institute for Biomedicine, Anhui Medical University, Hefei, China.
Lancet. 2007 Jun 2;369(9576):1876-1882. doi: 10.1016/S0140-6736(07)60854-X.
The efficacy of treatments that lower homocysteine concentrations in reducing the risk of cardiovascular disease remains controversial. Our aim was to do a meta-analysis of relevant randomised trials to assess the efficacy of folic acid supplementation in the prevention of stroke.
We collected data from eight randomised trials of folic acid that had stroke reported as one of the endpoints. Relative risk (RR) was used as a measure of the effect of folic acid supplementation on the risk of stroke with a random effect model. The analysis was further stratified by factors that could affect the treatment effects.
Folic acid supplementation significantly reduced the risk of stroke by 18% (RR 0.82, 95% CI 0.68-1.00; p=0.045). In the stratified analyses, a greater beneficial effect was seen in those trials with a treatment duration of more than 36 months (0.71, 0.57-0.87; p=0.001), a decrease in the concentration of homocysteine of more than 20% (0.77, 0.63-0.94; p=0.012), no fortification or partly fortified grain (0.75, 0.62-0.91; p=0.003), and no history of stroke (0.75, 0.62-0.90; p=0.002). In the corresponding comparison groups, the estimated RRs were attenuated and insignificant.
Our findings indicate that folic acid supplementation can effectively reduce the risk of stroke in primary prevention.
降低同型半胱氨酸浓度的治疗方法在降低心血管疾病风险方面的疗效仍存在争议。我们的目的是对相关随机试验进行荟萃分析，以评估补充叶酸预防中风的疗效。
我们收集了八项以中风为终点之一的叶酸随机试验数据。采用随机效应模型，用相对风险（RR）衡量补充叶酸对中风风险的影响。分析进一步按可能影响治疗效果的因素进行分层。
补充叶酸可使中风风险显著降低18%（RR 0.82，95%可信区间0.68 - 1.00；p = 0.045）。在分层分析中，治疗持续时间超过36个月的试验（0.71，0.57 - 0.87；p = 0.001）、同型半胱氨酸浓度降低超过20%的试验（0.77，0.63 - 0.94；p = 0.012）、未强化或部分强化谷物的试验（0.75，0.62 - 0.91；p = 0.003）以及无中风病史的试验（0.75，0.62 - 0.90；p = 0.002）中，观察到更大的有益效果。在相应的对照组中，估计的RR值减弱且无统计学意义。
我们的研究结果表明，补充叶酸可有效降低一级预防中中风的风险。
