Bone aluminium content in Alzheimer's disease.

The possible association between aluminium and Alzheimer's disease is still contentious. If aluminium neurotoxicity is implicated in the pathophysiology of Alzheimer's disease, it may result either from excessive aluminium exposure or increased brain aluminium uptake. In a pilot study to test the former hypothesis, trabecular bone aluminium content, which reflects long-term aluminium exposure, was evaluated in 7 patients with a clinical diagnosis of senile dementia of the Alzheimer type (SDAT; mean age 80.8 +/- 3.35 years) and 19 non-demented age-matched controls (mean age 79.6 +/- 6.09 years). Trabecular bone was obtained from post-traumatic femoral neck fracture specimens taken from patients during femoral head prosthesis surgery. Bone aluminium content was expressed quantitatively by atomic absorption spectrometry and qualitatively by the acid solochrome azurine histological staining technique. Quantitative analysis showed a lower aluminium content in the SDAT (11.9 +/- 4.04 micrograms/g dry bone) versus the non-demented group (18.2 +/- 7.37 micrograms/g), which was significant at the 95% but not at the 99% confidence limit. Aluminium deposition from qualitative histological analysis was not detectable in either group. These results do not support a hypothesis of excessive aluminium absorption and tissue accumulation in Alzheimer's disease.