ABSTRACT
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. 2 1, 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 hetween 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.