Trace metal concentrations in hair and nails from Alzheimer's disease patients: Relations with clinical severity

Background and objectives: Metals, especially transition metals, seem to be important in the pathogenesis of Alzheimer disease. This study aims to determine the relationship of trace metal elements to the pathogenesis and/or course of Alzheimer Disease in terms of clinical severity. Methods: The hair and nail trace metal levels of 62 Alzheimer Disease patients at different clinical stages (21 mild, 20 moderate, 21 severe) and 60 healthy control subjects were measured by using inductively coupled plasma-mass spectrometry. The statistical comparisons were performed with regards to the study groups, clinical stages, disease duration and age. Results: The patient and control groups were significantly different from each other in regards to Mn, Fe, Cu, Cd, Hg (p <0.001), Zn (p < 0.01) in nail concentrations and, Na, Al, Pb, Co (p < 0.001), Fe, Mn (p = 0.001), Hg, Cu, Cd, K in hair concentrations (p < 0.01). No difference was detected in the levels of Mg and Ca. Nail Na level showed differences among different clinical stages of the disease (p < 0.01). In comparing the mild degree Alzheimer patients to the control group; significant differences were detected in nail Mn, Fe, Cu, Co (p < 0.001), Hg, Zn (p < 0.01) and, hair Pb, Al (p < 0.001), Na, K levels (p < 0.01). Conclusions: Our results have shown that transition and posttransition metals are especially important metals for the disease process. The relation of nail Na level with clinical stages of AD is an interesting new finding, making someone to think that alkali metals may be important in the progression of the disease. (C) 2016 Published by Elsevier GmbH.