title: Homocysteine, antioxidant micronutrients and late onset dementia.
abstract: OBJECTIVE
  To distinguish between contributions to dementia made by homocysteine, folate, B12 and antioxidant micronutrients.
  
  
  METHODS
  This is a follow-up study of a sample reported in 2002. Homocysteine was measured at baseline in 201 individuals born in 1921 and without dementia at age 77 years and followed up to age 88 years. Baseline macro- and micronutrient status was estimated from BMI, the MONICA food frequency questionnaire, plasma folate, B12 and, in a subgroup (N = 173), plasma antioxidant micronutrients. Time to dementia onset during follow-up was compared between participants grouped by homocysteine concentration using Cox regression. Model 1 adjusted for age, sex, childhood IQ, education, socioeconomic deprivation, presence of heart disease, hypertension, plasma folate and B12. In model 2 plasma, antioxidants were added to these covariables.
  
  
  RESULTS
  During a mean follow-up of about 5 years, there were 39 incident dementia cases among 201 participants. In model 1, being in the highest homocysteine group (>14 μmol/L) was associated with a 234 % increased risk (HR 3.34, 95 % CI 1.16-9.57) of any dementia. After inclusion of plasma antioxidants in model 2, there were 32 incident dementia cases from a subsample (N = 173). Homocysteine >14 μmol was associated with a 272 % increased dementia risk (HR = 3.72, 95 % CI 1.06-13.08).
  
  
  CONCLUSIONS
  High homocysteine increases the risk of dementia. The association between tHcy and dementia is independent of plasma folate, B12 and antioxidant micronutrient status.
authors.affiliation: Institute of Applied Health Sciences, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, Scotland, AB25 2ZH, UK, l.j.whalley@abdn.ac.uk.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Whalley
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Duthie
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Collins
authors.forename: John M
authors.initials: JM
authors.lastname: Starr
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.forename: Helen
authors.initials: H
authors.lastname: Lemmon
authors.forename: Ashleigh C
authors.initials: AC
authors.lastname: Duthie
authors.forename: Alison D
authors.initials: AD
authors.lastname: Murray
authors.forename: Roger T
authors.initials: RT
authors.lastname: Staff
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000378:metabolism*; D015992:Body Mass Index; D003071:Cognition / Q000502:physiology; D003704:Dementia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D005492:Folic Acid / Q000097:blood; D005500:Follow-Up Studies; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000150:complications; D008297:Male; D018977:Micronutrients / Q000097:blood*; D015596:Nutrition Assessment; D016016:Proportional Hazards Models; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D000975:Antioxidants; D018977:Micronutrients; D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12