Recent studies have shown that the abnormal accumulation of endogenous formaldehyde could be a critical factor in age-related cognitive decline. The aim of this study was to estimate the correlation between uric formaldehyde and general cognitive abilities in a community-based elderly population, and to measure the extent and direction in which the correlation varied with demographic characteristics. Using a double-blind design, formaldehyde in human urine was analyzed by high-performance liquid chromatography(n = 604), and general cognitive abilities were measured using the Montreal Cognitive Assessment(MoCA). Demographic characteristics, in terms of age, gender, residential region, and education were taken into consideration. We found that uric formaldehyde levels were inversely correlated with the MoCA score, and the concentration varied with demographic features: higher odds of a high formaldehyde level occurred among the less educated and those living in old urban or rural areas. In cytological experiments, the level of cellular formaldehyde released into the medium increased as SH-SY5Y and BV2 cells were incubated for three days. Formaldehyde in excess impairedthe processes of N2a cells and neurites of primary cultured rat hippocampal cells. However, removal of formaldehyde markedly rescued and regenerated the processes of N2a cells. These results demonstrated a negative correlation between the endogenous formaldehyde and general cognitive abilities. High formaldehyde levels could be a risk factor for cognitive impairment in older adults, and could be developed as a non-invasive marker for detection and monitoring of age-related cognitive impairment.
Jing YuTao SuTing ZhouYingge HeJing LuJuan LiRongqiao He
目的:评估老年人饮茶习惯与认知功能的关系及是否存在性别差异。方法:在北京市通过分层、方便取样的方式选取老年人1056人(年龄≥60岁),获有效样本868份。采用自编一般资料调查表调查一般人口学资料及饮茶习惯(包括饮茶史,饮茶类型,饮茶频率,饮茶持续时间),简明精神状态评估量表(MMSE)、瑞氏听觉词语学习测验(RAVLT,包括即刻回忆和延迟回忆)、词语配对联想学习测验(VPALT)、韦氏木块图测验评估认知功能。结果:饮茶组的RAVLT即刻回忆得分高于未饮茶组(P=0.010),绿茶组的M M SE、RAVLT、VPALT、韦氏木块图测验得分均高于未饮茶组(均P<0.001)。RAVLT延迟回忆得分在性别和饮茶史之间存在交互效应(P=0.023),饮茶者的RAVLT延迟回忆得分高于未饮茶者(P=0.006)。多因素逐步回归分析显示,饮茶与RAVLT即刻回忆得分(β=2.47)、延迟回忆得分正向关联(β=1.51);饮用绿茶与RAVLT即刻回忆得分(β=3.05)、延迟回忆得分正向关联(β=2.28)。结论:在老年人中,较高的即刻回忆及延迟回忆水平与饮茶可能相关,其获益主要来自绿茶。
