Vidal Jean-Sébastien, Dufouil Carole, Ducros Véronique, Tzourio Christophe
INSERM, U708, Paris, France.
Neuroepidemiology. 2008;30(4):207-14. doi: 10.1159/000126914. Epub 2008 Apr 18.
Hyperhomocysteinemia is associated with an increased risk of cognitive impairment in the elderly. Recent studies suggest that folate level may also influence the course of cognitive decline.
We performed the cross-sectional analysis of the relationship between homocysteine and folate levels and cognitive performances in a population-based study including 3,914 subjects aged 65 years and older.
Subjects had an evaluation of their cognitive level using five neuropsychological tests. A Cognitive Summary Score was computed as the sum of each of the 5 cognitive tests score standardized. Relations of folate and homocysteine levels with cognition were first studied separately in a covariance analysis. Stratified analyses were also performed because of interaction between folate and homocysteine in relation to cognition.
Subjects in the higher quartile of homocysteine (high homocysteine group) and subjects in the lower quartile of folate (low folate group) had consistently lower cognitive performances in all tests. When stratified on folate level, high homocysteinemia was associated with lower cognitive performances only in subjects with a low folate level.
In this large population-based sample of elderly people, the association between high homocysteinemia and decreased cognition was only seen in participants with low folate levels.
高同型半胱氨酸血症与老年人认知障碍风险增加相关。近期研究表明叶酸水平可能也会影响认知衰退进程。
在一项纳入3914名65岁及以上受试者的基于人群的研究中，我们对同型半胱氨酸和叶酸水平与认知表现之间的关系进行了横断面分析。
受试者通过五项神经心理学测试对其认知水平进行评估。计算认知综合得分，即5项认知测试标准化得分的总和。在协方差分析中首先分别研究叶酸和同型半胱氨酸水平与认知的关系。由于叶酸和同型半胱氨酸在认知方面存在相互作用，还进行了分层分析。
同型半胱氨酸处于较高四分位数的受试者（高同型半胱氨酸组）和叶酸处于较低四分位数的受试者（低叶酸组）在所有测试中的认知表现始终较低。当按叶酸水平分层时，高同型半胱氨酸血症仅在低叶酸水平的受试者中与较低的认知表现相关。
在这个基于人群的大型老年样本中，高同型半胱氨酸血症与认知能力下降之间的关联仅在低叶酸水平的参与者中出现。
