title: Methylenetetrahydrofolate reductase polymorphism determines the plasma homocysteine-lowering effect of large-dose folic acid supplementation in patients with cardiovascular disease.
abstract: OBJECTIVE
  The polymorphism of the gene encoding methylenetetrahydrofolate reductase (MTHFR) and folic acid nutritional status play important roles in atherosclerosis. The present study investigated the total homocysteine-lowering effect of folic acid in response to the MTHFR genotype in patients who have cardiovascular disease.
  
  
  METHODS
  Twenty-three patients who had cardiovascular disease (ages 44 to 88 y) were supplemented with 5 mg of folic acid/d for 8 wk. Blood samples were collected before and after supplementation for the measurement of folic acid. The presence of the 677C-->T mutation was assessed by polymerase chain reaction followed by restriction enzyme analysis.
  
  
  RESULTS
  After the 8 wk of folic acid supplementation, plasma total homocysteine decreased 40% in patients who had the TT genotype, 23% in those who had the CT genotype, 10% in those who had the CC genotype, and 27% in carriers of the T allele. The plasma total homocysteine-lowering effect of folic acid was significant only in patients who had the CT genotype and in carriers of the T allele.
  
  
  CONCLUSIONS
  The MTHFR polymorphism may be involved in the total homocysteine-lowering effect of folic acid in patients who have cardiovascular disease.
authors.affiliation: Department of Neurology and Neuroscience, Changhua Christian Hospital, Changhua, Taiwan.
authors.forename: Chin-San
authors.initials: CS
authors.lastname: Liu
authors.forename: Hui-Chin
authors.initials: HC
authors.lastname: Chiang
authors.forename: Haw-Wen
authors.initials: HW
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002318:Cardiovascular Diseases; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage*; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000188:drug therapy*; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015183:Restriction Mapping; D016896:Treatment Outcome
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2)