Aging Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Institute of Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy.
Exp Gerontol. 2013 Dec;48(12):1428-35. doi: 10.1016/j.exger.2013.09.006. Epub 2013 Oct 7.
Vitamin E includes eight natural antioxidant compounds (four tocopherols and four tocotrienols), but α-tocopherol has been the main focus of investigation in studies of cognitive impairment and Alzheimer's disease.
To investigate the association between serum levels of tocopherols and tocotrienols, markers of vitamin E oxidative/nitrosative damage (α-tocopherylquinone, 5-nitro-γ-tocopherol) and incidence of cognitive impairment in a population-based study.
A sample of 140 non-cognitively impaired elderly subjects derived from the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) study was followed-up for 8years to detect cognitive impairment, defined as development of mild cognitive impairment (MCI) or Alzheimer's dementia. The association between baseline serum vitamin E and cognitive impairment was analyzed with multiple logistic regression after adjusting for several confounders.
The risk of cognitive impairment was lower in subjects in the middle tertile of the γ-tocopherol/cholesterol ratio than in those in the lowest tertile: the multiadjusted odds ratio (OR) with 95% confidence interval (CI) was 0.27 (0.10-0.78). Higher incidence of cognitive impairment was found in the middle [OR (95% CI): 3.41 (1.29-9.06)] and highest [OR (95% CI): 2.89 (1.05-7.97)] tertiles of the 5-NO2-γ-tocopherol/γ-tocopherol ratio. Analyses of absolute serum levels of vitamin E showed lower risk of cognitive impairment in subjects with higher levels of γ-tocopherol, β-tocotrienol, and total tocotrienols.
Elevated levels of tocopherol and tocotrienol forms are associated with reduced risk of cognitive impairment in older adults. The association is modulated by concurrent cholesterol concentration. Various vitamin E forms might play a role in cognitive impairment, and their evaluation can provide a more accurate measure of vitamin E status in humans.
维生素 E 包含八种天然抗氧化化合物（四种生育酚和四种三烯生育酚），但 α-生育酚一直是研究认知障碍和阿尔茨海默病的主要焦点。
在一项基于人群的研究中，调查血清生育酚和三烯生育酚水平（维生素 E 氧化/硝化损伤标志物：α-生育酚醌、5-硝基-γ-生育酚）与认知障碍发生率之间的关系。
从心血管危险因素、衰老和痴呆（CAIDE）研究中提取出 140 名无认知障碍的老年受试者作为样本，随访 8 年以检测认知障碍，定义为发展为轻度认知障碍（MCI）或阿尔茨海默病痴呆。在调整了几个混杂因素后，使用多变量逻辑回归分析了基线血清维生素 E 与认知障碍之间的关系。
γ-生育酚/胆固醇比值处于中间三分位的受试者发生认知障碍的风险低于处于最低三分位的受试者：多调整后的比值比（OR）及其 95%置信区间（CI）为 0.27（0.10-0.78）。5-NO2-γ-生育酚/γ-生育酚比值处于中间 [OR（95%CI）：3.41（1.29-9.06）] 和最高 [OR（95%CI）：2.89（1.05-7.97）] 三分位的受试者认知障碍发生率较高。维生素 E 血清绝对水平分析显示，γ-生育酚、β-生育三烯酚和总三烯生育酚水平较高的受试者认知障碍风险较低。
较高的生育酚和三烯生育酚形式与老年人认知障碍风险降低相关。这种关联受胆固醇浓度的调节。各种维生素 E 形式可能在认知障碍中发挥作用，其评估可以为人类维生素 E 状态提供更准确的衡量标准。
