Magnesium and potassium status in elderly subjects with and without dementia of the Alzheimer type.

Magnesium status was evaluated in healthy elderly people, and in patients affected from dementia of the Alzheimer type. Magnesium levels were determined in plasma, erythrocytes (RBC), lymphocytes (MNC), and granulocytes (PMN), and were compared with measurements in young healthy adults. Significantly lower plasma Mg concentrations were found in elderly people compared to controls, with no difference between cognitively normal and demented subjects. Mg levels in healthy elderly people were higher in MNC and lower in PMN, compared to the younger group. No difference was observed between demented patients and young controls in Mg content of white blood cells, but the patients had higher Mg/K ratios. In addition, significant correlations were found between cognitive impairment and the Mg/K ratio in MNC. When we assessed the philothermal response of granulocytes, a significant correlation was observed in demented subjects between the migration rate of PMNs and the PMN Mg/K ratio.