Correlations between folate, B12, homocysteine levels, and radiological markers of neuropathology in elderly post-stroke patients

OBJECTIVE: To investigate serum levels of folate, B12, and total homocysteine (tHcy) in elderly post-stroke patients, and the possible correlations with radiological markers of neuropathology. DESIGN: Cross-sectional study. SETTING: Department of Neurology, Cardinal Tien Hospital. SUBJECTS: Eighty-nine elderly post-stroke patients were enrolled for dietary assessment and blood tests. Neuroradiological assessment was done in 62 of these patients. MAIN OUTCOME MEASURES: Dietary folate and vitamin B12 intakes were evaluated by a 24-h recall system using a semi-quantitative questionnaire. Circulating levels of folate, B12, and tHcy were measured. Magnetic resonance imaging (MRI) or computed tomography (CT) was used for evaluation of brain lesions including infarction and atrophy. RESULTS: Mean folate and B12 intakes of these post-stroke patients were 69% and 261% of the recommended dietary allowances (RDA), respectively. Inadequate folate levels, defined as serum folate < 6 ng/mL, was noted in 68% of these patients. Hyperhomocysteinemia levels (tHcy >or=15 micromol/L) were observed in 48%. According to tertiles of serum tHcy and folate levels, the rate of brain atrophy, but not brain infarctions, are significantly associated with elevated tHcy (P = 0.0126) and decreased folate levels (P = 0.0273). After adjustments for age, sex, disease status, brain infarctions and carotid stenosis, the odds ratio of brain atrophy was 9.8 (95% CI: 1.7-56.4, P = 0.0101) in the hyperhomocysteinemia group and 9.6 (95% CI: 1.1-81.3, P = 0.0377) in the low folate group (serum folate < 3.0 ng/mL) compared with the group with normal tHcy and folate levels. No significant association was noted between vitamin B12 levels and brain lesions. CONCLUSIONS: Our data shows that folate deficiency and hyperhomocysteinemia are prevalent in elderly post-stroke patients. These two conditions are strongly and independently associated with the development of brain atrophy.