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

Abstract

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.

Plasma homocysteine, brain imaging and cognition in older patients with mental illness

“…Thus, pathological CT findings indicating cerebrovascular disease did not predict MMSE score. Age explained most (predictive value 16.2%) of the variability of MMSE scores, whereas plasma tHcy explained 5% of the variability, which is in accordance with our previous study (Nilsson et al , ). Although the main determinants of plasma tHcy were investigated, plasma tHcy has also been associated with genetic polymorphisms and several negative lifestyle factors such as smoking, alcohol intake, and low physical activity (Refsum et al , ).…”

“…We have recently investigated the relation between plasma tHcy and cognition in older patients with mental illness and observed that age and plasma tHcy were the main predictors of cognition (Nilsson et al , ). In the present study, we have examined the relationship between plasma tHcy, cerebrovascular disease, as evaluated by brain imaging (computer tomography scan [CT]), and cognition, measured as Mini mental state examination (MMSE) score, in consecutively enrolled older patients with mental illness.…”

Homocysteine and cognition: A systematic review of 111 studies

“…Eight case studies with cross sectional analyses of cases included people suffering from AD or cognitive impairment. Four of them, showed an inverse association between the plasma Hcy levels and the MMSE scores (47)(48)(49)(50). Similarly, two other studies stated that high plasma Hcy levels are a risk factor for MCI (51,52).…”

“…This negative association holds for all populations as shown in the subgroup analysis (Figure 5). Despite this effect across all clinical conditions, tests showed a significant between-group heterogeneity (Q=34.54, p<0.001), although the high within-group heterogeneity in Alzheimer's studies(47)(48)(49) and the small number of studies in the other subgroups render this test questionable.…”

Hydrogen Sulfide Ameliorates Homocysteine-Induced Alzheimer’s Disease-Like Pathology, Blood–Brain Barrier Disruption, and Synaptic Disorder

“…An elevated plasma homocysteine level, known as hyperhomocystemia (HHcy), was found to be associated with an increased risk factor for strokes [1], vascular dementia, and Alzheimer's disease (AD) [2-3]. HHcy levels also predict cognitive decline in healthy elderly patients [4-5].…”