Homocysteine in Alzheimer disease and vascular dementia.

Hyperhomocysteinemia is an important risk factor for atherosclerosis and it has recently been suggested as a diagnostic marker for Alzheimer disease (AD). The present studies compared homocysteinemia in patients with AD and with vascular dementia (VD),as well as in controls. Homocysteinemia was measured in 137 probable AD patients,diagnosed by the NINCDS-ADRDA criteria, in 40 probably VD patients diagnosed by the NINDS-AIREN criteria, and in 42 control subjects. Homocysteine levels were significantly higher in AD and VD groups, than in controls, however, VD patients were significantly older than the controls. The proportion of females was higher in the AD group, while serum folate and B12 vitamin levels tended to be lower in both the AD and VD groups, compared to the controls. In order to adjust the results for these potentially interfering factors, a multivariate ANCOVA calculation was performed, where homocysteine levels were analyzed considering 2 grouping factors (gender and neurological type) and 4 covariates (age, albumin,serum folate and vitamin B12 ). This analysis confirmed that even after adjusting for the covariates, the difference between AD and VD groups and controls remain highly significant,while neither the gender itself, nor the interaction of gender and the neurological type had any significant influence on the homocysteine levels. The main finding, therefore, is a significant increase of homocysteine levels in the 2 disease groups, compared to controls.