Effects of homocysteine lowering with B vitamins on cognitive aging: meta-analysis of 11 trials with cognitive data on 22,000 individuals
Effects of homocysteine lowering with B vitamins on cognitive aging: meta-analysis of 11 trials with cognitive data on 22,000 individuals
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DOI：
10.3945/ajcn.113.076349
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发表时间：
2014-08-01
影响因子：
7.1
通讯作者：
Grodstein, Francine
中科院分区：
文献类型：
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作者：
Clarke, Robert;Bennett, Derrick;Grodstein, Francine
背景资料：血浆同型半胱氨酸升高是阿尔茨海默病的危险因素，但同型半胱氨酸降低与认知老化速度的相关性尚不确定。目的：本研究的目的是评估服用B族维生素与安慰剂治疗数年后，对认知功能、整体认知功能和认知老化复合领域的影响。设计：荟萃分析使用了来自22，000名参与者的11项大型试验的数据。基于域的z分数（记忆力、速度和执行功能以及整体认知功能的领域复合评分）（平均持续时间：2.3年）（1340人）;在治疗结束时进行简易精神状态检查（MMSE）类型测试结果：随着年龄的增长，领域复合和MMSE型整体认知功能z得分均呈下降趋势（平均SE分别为0.054 ± 0.004和0.036 ± 0.001/y）。在认知领域试验中，分配给B族维生素使同型半胱氨酸浓度降低了28%，但对个体领域或整体认知功能的z评分与基线的差异没有显著影响（z评分差异：0.00; 95% CI：0.05，0.06）。同样，在整体认知试验中，分配给B族维生素使同型半胱氨酸降低了26%，但对治疗结束时MMSE型整体认知功能没有显著影响（z评分差异：0.01; 95% CI：0.03，0.02）。总体而言，同型半胱氨酸减少25%的效果相当于0.02年（95%CI：0.10，0.13年）的认知老化每年，并排除减少>1个月每年的treatment.Conclusion：同型半胱氨酸降低使用B族维生素对个人认知领域或全球认知功能或认知老化没有显着影响。
Background: Elevated plasma homocysteine is a risk factor for Alzheimer disease, but the relevance of homocysteine lowering to slow the rate of cognitive aging is uncertain.Objective: The aim was to assess the effects of treatment with B vitamins compared with placebo, when administered for several years, on composite domains of cognitive function, global cognitive function, and cognitive aging.Design: A meta-analysis was conducted by using data combined from 11 large trials in 22,000 participants. Domain-based z scores (for memory, speed, and executive function and a domain-composite score for global cognitive function) were available before and after treatment (mean duration: 2.3 y) in the 4 cognitive-domain trials (1340 individuals); Mini-Mental State Examination (MMSE) type tests were available at the end of treatment (mean duration: 5 y) in the 7 global cognition trials (20,431 individuals).Results: The domain-composite and MMSE-type global cognitive function z scores both decreased with age (mean SE: 0.054 0.004 and 0.036 0.001/y, respectively). Allocation to B vitamins lowered homocysteine concentrations by 28% in the cognitive-domain trials but had no significant effects on the z score differences from baseline for individual domains or for global cognitive function (z score difference: 0.00; 95% CI: 0.05, 0.06). Likewise, allocation to B vitamins lowered homocysteine by 26% in the global cognition trials but also had no significant effect on end-treatment MMSE-type global cognitive function (z score difference: 0.01; 95% CI: 0.03, 0.02). Overall, the effect of a 25% reduction in homocysteine equated to 0.02 y (95% CI: 0.10, 0.13 y) of cognitive aging per year and excluded reductions of >1 mo per year of treatment.Conclusion: Homocysteine lowering by using B vitamins had no significant effect on individual cognitive domains or global cognitive function or on cognitive aging.