P2-040: vitamin b12 supplementation improves hyperhomocysteinemia and cognitive impairment in patients with vitamin b12 deficiency

Vitamin B12 (Vit B12) deficiency is reported to be associated with hyperhomocysteinemia (HHCy), cognitive decline and hippocampal atrophy. However, recovery of cognitive impairment and the homocysteine (Hcy) level by vit B12 therapy, and its relationship with hippocampal volume remains unclear. Objective: Thus, we examined cognitive function and Hcy levels in patients with cognitive impairment and vit B12 deficiency. The recovery of cognition and HHCy by vit B12 administration, and relationship of hippocampal volume was also investigated. Among the participants who visited our Dementia Outpatient Clinic, those with cognitive impairment and low serum folate were enrolled. All participants underwent the Mini-Mental State Examination (MMSE), the Revised Hasegawa's Dementia Scale (HDS-R), and laboratory tests, including folate, vitamin B12, and Hcy. Hippocampal volume was estimated by brain MRI. They were given mecovalamine (1,500 μg/day) and re-examined after 30 to 60 days. Of the 940 patients who visited our Dementia Outpatient Clinic, 33 (3.5%) patients (mean age of 78.1 ± 10.3 years old) with vit B12 deficiency were enrolled. The mean Hcy value significantly decreased from 30.1 ± 10.4 to 11.4 ± 2.1 nmol/mL (p <0.01). There was inverse correlation between vit B12 levels and Hcy value (p ＜0.05, r= - 0.402). The mean MMSE scores after vit B12 supplementation significantly improved from 20.7 ± 6.1 to 21.4 ± 5.3 (P <0.01). There was no significant correlation between recovery of cognition and the degree of hippocampal atrophy. Vit B12 deficiency induced HHcy, and vit B12 supplementation improved HHCy. Folate improved cognitive function, at least for a short period, in patients with folate deficiency.