Serum Homocysteine, Vitamin B₁₂, Folate, and Their Association with Mild Cognitive Impairment and Subtypes of Dementia

Article type: Research Article

Authors: Song, Yang^a | Quan, Meina^a | Li, Tingting^a | Jia, Jianping^{a; b; c; d; e; *}

Affiliations: [a] Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, National Clinical Research Center for Geriatric Diseases, Beijing, P.R. China | [b] Beijing Key Laboratory of Geriatric Cognitive Disorders, Beijing, P.R. China | [c] Clinical Center for Neurodegenerative Disease and Memory Impairment, Capital Medical University, Beijing, P.R. China | [d] Center of Alzheimer’s Disease, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, P.R. China | [e] Key Laboratory of Neurodegenerative Diseases, Ministry of Education, Beijing, P.R. China

Correspondence: [*] Correspondence to: Jianping Jia, Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, P.R. China. Tel.: +86 10 83199449; E-mail:jjp@ccmu.edu.cn.

Abstract: Background:Although elevated levels of homocysteine (Hcy) are associated with cognitive impairment and dementia, the relevance of Hcy, vitamin B12, and folate levels to subtypes of dementia are still unknown. Objective:To investigate the changes of Hcy, vitamin B12, and folate levels in mild cognitive impairment (MCI) and subtypes of dementia including Alzheimer’s disease (AD), vascular dementia (VaD), frontotemporal dementia (FTD), and Lewy body dementia (LBD), and their relationships with cognitive function and magnetic resonance imaging (MRI) markers. Methods:We measured serum levels of Hcy, vitamin B12, and folate in 257 subjects. Each subject underwent cognitive function assessment and brain MRI test. The Fazekas and temporal lobe atrophy (MTA) visual rating scales were used to assess the degree of white matter hyperintensities and MTA, respectively. Results:Serum levels of Hcy was higher and vitamin B12 was lower in AD, VaD, FTD, and LBD groups than cognitively normal controls. No significant differences of folate levels were found among 6 groups. Hcy levels were positively correlated with MTA total score in AD (r = 0.448, p < 0.001). Vitamin B12 levels were positively correlated with MoCA in VaD (r = 0.497), and negatively correlated with MTA total score in AD (r = – 0.325) (ps < 0.05). Hyperhomocysteinemia may increase the risk of AD (OR = 2.744), VaD (OR = 3.600), and FTD (OR = 3.244) in the adjusted model (ps < 0.05). Conclusion:Hcy and vitamin B12 levels are associated with MTA in AD. Vitamin B12 levels are associated with general cognition in VaD. Hyperhomocysteinemia is a risk factor for not only AD and VaD but also FTD.

Keywords: Alzheimer’s disease, B vitamin, dementia, frontotemporal dementia, homocysteine, Lewy body dementia, mild cognitive impairment, vascular dementia

DOI: 10.3233/JAD-220410

Journal: Journal of Alzheimer's Disease, vol. 90, no. 2, pp. 681-691, 2022