Dong Yonghai, Chen Xiaodan, Liu Yun, Shu Yan, Chen Ting, Xu Lei, Li Meng, Guan Xihong
Jiangxi Province Center for Disease Control and Prevention, Nanchang, China.
Jiangxi Provincial Cancer Hospital, Nanchang, China.
Int J Geriatr Psychiatry. 2018 Feb;33(2):e257-e263. doi: 10.1002/gps.4780. Epub 2017 Aug 23.
Whether low-serum vitamin E increases the risk of Alzheimer disease (AD) in older people remains inconclusive. This meta-analysis aims to synthesize evidence-based case-control studies to evaluate the association between serum vitamin E and the risk of AD.
Potentially relevant studies were selected through PubMed, Embase, Wanfang, Chongqing VIP, and China National Knowledge Infrastructure databases by using the core terms Vitamin E/alpha-tocopherol and Alzheime's disease/senile dementia/AD in the titles, abstracts, and keywords of the articles. The association between serum vitamin E levels and AD was estimated by using the weighted mean difference (WMD) and 95% confidence interval by adopting a random effects model. Heterogeneity was assessed by using Cochran Q test and I statistic. Forest plot was used to present the results graphically from meta-analysis. Publication bias was evaluated by using funnel plots and Egger test.
We identified 17 studies that met the eligibility criteria. The studies included 2057 subjects with 904 AD patients and 1153 controls. The results indicated that AD patients had a lower concentration of serum vitamin E compared with healthy controls among older people (WMD = -6.811 μmol/L, 95% confidence interval -8.998 to -4.625; Z = -6.105, P < .001). Publication bias was not detected and sensitivity analysis performed by omitting each study, and calculating the pooled WMD again for the remaining studies indicated the results stable.
Alzheimer disease is associated with a low concentration of serum vitamin E in older people. However, necessary prospective cohort studies should be conducted to determine the risk of serum vitamin E for AD in the future.
血清维生素E水平降低是否会增加老年人患阿尔茨海默病（AD）的风险尚无定论。本荟萃分析旨在综合基于证据的病例对照研究，以评估血清维生素E与AD风险之间的关联。
通过在PubMed、Embase、万方、维普和中国知网数据库中检索，使用文章标题、摘要和关键词中的核心术语“维生素E/α-生育酚”和“阿尔茨海默病/老年痴呆症/AD”，筛选出潜在相关研究。采用随机效应模型，通过加权平均差（WMD）和95%置信区间评估血清维生素E水平与AD之间的关联。使用Cochran Q检验和I统计量评估异质性。森林图用于以图形方式展示荟萃分析的结果。使用漏斗图和Egger检验评估发表偏倚。
我们确定了17项符合纳入标准的研究。这些研究包括2057名受试者，其中904例AD患者和1153名对照。结果表明，在老年人中，AD患者的血清维生素E浓度低于健康对照（WMD = -6.811 μmol/L，95%置信区间为-8.998至-4.625；Z = -6.105，P <.001）。未检测到发表偏倚，通过逐一剔除每项研究进行敏感性分析，并对其余研究重新计算合并WMD，结果显示稳定。
老年人患阿尔茨海默病与血清维生素E浓度低有关。然而，未来需要进行必要的前瞻性队列研究，以确定血清维生素E对AD的风险。
