Plasma Homocysteine and Cognition in Elderly Patients with Dementia or Other Psychogeriatric Diseases

Background: Total plasma homocysteine (tHcy) concentration is elevated in elderly patients with mental illness, and patients with vascular disease have higher plasma tHcy concentrations than patients without vascular disease. Increasing evidence indicates that vascular risk factors play a role in the development of cognitive impairment. Method: We have investigated the relation between plasma tHcy, its determinants and cognition, measured as MMSE, in 448 consecutively enrolled patients with dementia or other psychogeriatric diseases. Results: Multiple regression analyses showed that plasma tHcy was related to cognitive function in all patients as well as in demented and non-demented patients. The apparent close relationship between plasma tHcy and cognition was mainly dependent on its determinant age, whereas the other determinants of plasma tHcy exhibited a limited influence on the relation between plasma tHcy and cognition. Plasma tHcy has its own, albeit modest, relationship to cognitive function (predictive value about 5%). Conclusion: Plasma tHcy itself seems to play a minor role in cognitive impairment in patients with dementia or other psychogeriatric diseases. When investigating the relation between plasma tHcy and cognition, it is important to consider the distribution of the main determinants of plasma tHcy and to correct plasma tHcy for these variables. Copyright (C) 2010 S. Karger AG, Basel