Homocysteine, progression of ventricular enlargement, and cognitive decline: the Second Manifestations of ARTerial disease-Magnetic Resonance study.

Background: Homocysteine may be a modifiable risk factor for cognitive decline and brain atrophy, particularly in older persons. We examined whether homocysteine increased the risk for cognitive decline and brain atrophy, and evaluated the modifying effect of age.
Methods: Within the Second Manifestations of ARTerial disease-Magnetic Resonance study-a prospective cohort study among patients with atherosclerotic disease-longitudinal analyses were performed in 663 patients (mean age: 57 ± 9 years; follow-up: 3.9 ± 0.4 years). At baseline and follow-up, brain segmentation on magnetic resonance imaging was used to quantify relative (%) cortical, ventricular, and global brain volumes, and z-scores of memory and executive functioning were calculated. Linear regression analysis was used to estimate associations of homocysteine (per standard deviation increase) and hyperhomocysteinemia (HHCY) with brain volumes, memory, and executive functioning at follow-up, adjusted for baseline brain volume, memory, and executive functioning, respectively, and age, sex, and vascular risk factors. Furthermore, interaction terms between homocysteine and age (continuous) were added.
Results: Significant interactions were observed between total plasma homocysteine (tHcy) and age with cortical, ventricular, and global brain volume (for all three measures: P < .05), and between HHCY and age with executive functioning (P = .04), and results were stratified by age. In patients aged ≥65 years, increasing tHcy level and HHCY were significantly associated with progression of ventricular enlargement (B = 0.07%, 95% confidence interval [CI]: 0.01% to 0.13% and B = 0.16%, 95% CI: 0.01% to 0.31%, respectively) and with a decline in executive function (B = -0.29, 95% CI: -0.54 to -0.04 and B = -0.84, 95% CI: -1.37 to -0.32, respectively).
Conclusion: Elevated tHcy was related to progression of ventricular enlargement and increased the risk for a decline in executive functioning in older persons.
(Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)