Hair aluminium in normal aged and senile dementia of Alzheimer type

To investigate relationship between aluminium and senile dementia of Alzheimer type (SDAT), hair aluminium concentration was measured by ICP method in 35 cases of SDAT (mean 80 yr.) diagnosed clinically and 71 normal aged volunteers (mean 76 yr.). In normal aged, cerebral blood flow (CBF) also determined by Xe133 inhalation method simultaneously. Mean hair aluminium concentration in SDAT was within normal range of Japanese subjects and significantly lower than that of normal aged controls. There was no significant aging effect to hair aluminium concentration in both groups. Hair calcium and magnesium concentrations were significantly lower in SDAT than that of normal aged. Hair aluminium positively correlated to hair calcium and magnesium in SDAT. Hair aluminium negatively correlated to CBF, and CBF positively correlated to calcium and magnesium concentrations in hair in normal aged. Hair aluminium concentration does not appear to be of use in the diagnosis of SDAT. However, it is undeniable that decreased calcium and magnesium enhance selective accumulation of aluminium in the brain in SDAT. Inverse correlation between hair aluminium and CBF in normal aged suggests that aluminium might have some contribution to aging of the brain.