血浆重金属浓度与阿尔茨海默病和血管性痴呆的关系

Relationship between plasma heavy metal concentrations and Alzheimer＇s disease and vascular dementia

目的探讨重金属在阿尔茨海默病（Alzheimer’s disease，AD）和血管性痴呆（vascular dementia，VaD）发病过程中的作用，分析AD患者认知功能障碍与血浆重金属含量的关系。方法纳入50例AD患者、20例VaD患者和20例正常对照者，AD患者按临床痴呆分级量表（Clinical Dementia Rating，CDR）分为轻度痴呆组（CDR=1分）和中重度痴呆组（CDR：2～3分）。所有观察对象均行简易智能状态量表（Mini—Mental State Examination,MMSE）、Hachinski缺血指数评分和CDR评分，同时抽取空腹静脉血检测重金属（Cu、Ca、Fe、Me、Zn、Hg、Cr、Co、Se和Pb）的浓度。结果与对照组比较，轻度AD组和中重度AD组血浆Cu浓度显著增高[分别为（0．66±0．21）、（0．84±1．11）和（0．85±1．12）ng／g，P〈0．05]，轻度AD组与中重度AD组之间无显著差异。对照组Pb浓度显著低于中重度AD组[（22．79±3．94）ng／g对（40．82±16．96）ng／g，P〈0．05]，而对照组与轻度AD组以及轻度AD组与中重度AD组之间均无显著差异。AD组血浆cu浓度[（0．84±1．25）ng／g对（0．66±0．21）ng／g，P〈0．05]和Pb浓度[（32．42±14．12）ng／g对（22．79±3．94）ng／g，P〈0．05]均显著高于对照组，而VaD组与对照组之间金属浓度均无显著差异，VaD组和AD组之间的金属浓度亦无显著差异。结论部分重金属，如Cu和Pb可能参与了AD的发病过程，但重金属浓度与VaD的发病关系不大，AD患者的认知障碍程度与血浆金属浓度无显著相关性。

Objective To investigate the roles of heavy metals in the onset of Alzheimer ＇s disease （AD） and vascular dementia （VaD） and to analyze the relationship between cognitive impairment and plasma heavy metal concentrations in patients with AD. Methods Fifty patients with AD, 20 with VaD, and 20 healthy controls were included in the study. According to the Clinical Dementia Rating （CDR）, the AD patients were divided into mild dementia （CDR = 1 ） and moderate to severe dementia （CDR = 2 to 3 ） groups. All the observational subjects performed the Mini-Mental State Examination （MMSE） score, Hachinski ischemic index score, and CDR score. A fasting venous blood sample was taken from all the subjects for detection of the heavy metal （Tu, Ca, Fe, Me, Zn, Hg, Cr, Co, Se, and Pb） concentrations at the same time.Results Compared to the control group, the plasma Cu concentration in the mild dementia and moderate to severe dementia groups increased significantly （0.66 ±0.21, 0. 84 ± 1.11, and 0.85±1.12 ng/g, respectively （P 〈 0.05）. There was no significant difference between the mild AD group and the moderate to severe dementia group. The Pb concentration in the control group was significantly lower than that in the moderate to severe dementia group （22.79 ± 3.94 ng/gvs. 40.82±16.96 ng/g, P 〈 0.05 ）. While there were no significant differences between the control and the mild dementia and moderate to severe dementia groups. The plasma Cu concentration （0.84 ±1.25 ng/g vs. 0. 66±0.21 ng/g, P 〈 〈0.05） and Pb concentration （32.42±14. 12 ng/gvs. 22.79±3.94 ng/g, P 〈 0.05） in the AD group were significantly higher than that in the control group. While there was no significant difference between the VaD group and the control group for metal concentrations. There was also no significant difference for metal concentrations between the VaD group and the AD group. Conclusions Some heavy metals, such as Cu and Pb might have participated in the pathogenic process of AD, but the heavy metal concentrations did not have close relationship with the onset of VaD. There was no significant correlation between the degree of cognitive impairment and the plasma metal concentrations in patients with AD.