title: Associations between Alzheimer's disease and blood homocysteine, vitamin B12, and folate: a case-control study.
abstract: BACKGROUND
  There is a growing focus on nutritional therapy for Alzheimer's disease (AD), and controversy exists regarding the association between AD and homocysteine (Hcy), vitamin B12, and folate levels.
  
  
  OBJECTIVE
  The present study evaluated the association between AD and the combined levels of Hcy, vitamin B12, and folate.
  
  
  METHODS
  This case-control study consisted of 115 patients with AD and 115 matched controls. Serum folate and vitamin B12 were measured using an automated immunoassay analyzer. Plasma Hcy was measured using high-performance liquid chromatography. The association between AD and Hcy, vitamin B12, and folate was analyzed using binary logistic regression, adjusted for age and sex.
  
  
  RESULTS
  With the combination of normal blood Hcy, vitamin B12, and folate levels as the reference category, low vitamin B12 in subjects with normal Hcy and folate was associated with AD (adjusted odds ratio [OR], 4.6; 95% confidence interval [CI]: 1.6-13.2). The combination of low vitamin B12 and folate in subjects with normal Hcy was associated with AD (adjusted OR, 4.3; 95% CI: 1.3-14.6). The combination of high Hcy and low folate levels in patients with normal vitamin B12 was associated with AD (adjusted OR, 17.0; 95% CI: 5.4- 53.4). The combination of high Hcy, low vitamin B12, and any folate level was associated with AD (adjusted OR, 30.5; 95% CI: 9.7-95.9).
  
  
  CONCLUSIONS
  Vitamin B12 was directly associated with AD. The combination of high Hcy, low vitamin B12, and any folate level represented the poorest association with AD.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Shuai
authors.initials: S
authors.lastname: Liu
authors.forename: Lu
authors.initials: L
authors.lastname: Ji
authors.forename: Tianfeng
authors.initials: T
authors.lastname: Wu
authors.forename: Fei
authors.initials: F
authors.lastname: Ma
authors.forename: Yong
authors.initials: Y
authors.lastname: Ji
authors.forename: Yuying
authors.initials: Y
authors.lastname: Zhou
authors.forename: Miaoyan
authors.initials: M
authors.lastname: Zheng
authors.forename: Meilin
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin 300070, China. huangguowei@tmu.edu.cn.
authors.forename: Guowei
authors.initials: G
authors.lastname: Huang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000150:complications; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D003072:Cognition Disorders / Q000209:etiology; D016001:Confidence Intervals; D005260:Female; D005492:Folic Acid / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12