title: Moderately elevated plasma homocysteine, methylenetetrahydrofolate reductase genotype, and risk for stroke, vascular dementia, and Alzheimer disease in Northern Ireland.
abstract: OBJECTIVE
  Elevated plasma homocysteine level has been associated with increased risk for cardiovascular and cerebrovascular disease. Variation in the levels of this amino acid has been shown to be due to nutritional status and methylenetetrahydrofolate reductase (MTHFR) genotype.
  
  
  METHODS
  Under a case-control design we compared fasting levels of homocysteine and MTHFR genotypes in groups of subjects consisting of stroke, vascular dementia (VaD), and Alzheimer disease patients and normal controls from Northern Ireland.
  
  
  RESULTS
  A significant increase in plasma homocysteine was observed in all 3 disease groups compared with controls. This remained significant after allowance for confounding factors (age, sex, hypertension, cholesterol, smoking, creatinine, and nutritional measures). MTHFR genotype was not found to influence homocysteine levels, although the T allele was found to increase risk for VaD and perhaps dementia after stroke.
  
  
  CONCLUSIONS
  We report that moderately high plasma levels of homocysteine are associated with stroke, VaD, and Alzheimer disease. This is not due to vascular risk factors, nutritional status, or MTHFR genotype.
mesh_terms: D000368:Aged; D000483:Alleles; D000544:Alzheimer Disease / Q000097:blood / Q000453:epidemiology*; D001057:Apolipoproteins E / Q000235:genetics; D016022:Case-Control Studies; D015897:Comorbidity; D015140:Dementia, Vascular / Q000097:blood / Q000453:epidemiology*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000453:epidemiology* / Q000235:genetics; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D009660:Northern Ireland / Q000453:epidemiology; D009752:Nutritional Status; D016017:Odds Ratio; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D012016:Reference Values; D018570:Risk Assessment; D012307:Risk Factors; D016008:Statistical Distributions; D020521:Stroke / Q000097:blood / Q000453:epidemiology*
chemical_list: D001057:Apolipoproteins E; D006710:Homocysteine; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)