Free thyroxine, cognitive decline and depression in Alzheimer's disease.

The role of thyroid function in Alzheimer's disease (AD) has been subject to a number of studies during the last years. We investigated the possible relationship between plasma levels of the biologically active free form of thyroxin (fT4) and cognitive function in 227 outpatients with mild to moderate Alzheimer s disease (AD) in a cross-sectional study design. A significant negative correlation was found between plasma fT4-levels and Mini-Mental state examination (MMSE) score (Spearman Rho = -0.

Vitamin B 12 plasma concentrations in Alzheimer disease.

In this contribution we investigated the correlation between plasma vitamin B12 levels and cognitive impairment in Alzheimer's disease. We could demonstrate a significant inverse correlation when the MMSE scores of those patients with the lowest 10% Vitamin B12 plasma levels (<184 ng/ml) were compared with the upper 10% Vitamin B12 plasma levels (>598 ng/ml): p=0.008, Spearman-Rho= -0.