title: Prevalence of myocardial infarction is related to hyperhomocysteinemia but not influenced by C677T methylenetetrahydrofolate reductase and A2756G methionine synthase polymorphisms in diabetic and non-diabetic subjects.
abstract: BACKGROUND
  Hyperhomocysteinemia has emerged as a novel risk factor for myocardial infarction (MI). Some mechanisms proposed to explain its relationship with coronary events are also shared by major coronary risk factors. We examined whether C677T methylenetetrahydrofolate reductase and A2756G methionine synthase polymorphisms could affect the relative risk for MI.
  
  
  METHODS
  A sample of 196 individuals was divided into four groups (diabetics with MI, n=43; diabetics without MI, n=50; non-diabetics with MI, n=47; non-diabetics without MI, n=56) and compared regarding the prevalence of the polymorphisms, risk factors, and biochemical parameters.
  
  
  RESULTS
  Higher prevalence of hyperhomocysteinemia was found in MI patients (p<0.05 vs. non-MI subjects), in males (p<0.001 vs. female) and in those > or = 65 years (p=0.01 vs. <65 years). Homocysteine was negatively associated with HDL-C (p<0.05) and glucose, although results did not reach significance (p=0.06). Similar distribution of studied polymorphisms was seen in all groups, which presented normal folate and vitamin B12 serum levels.
  
  
  CONCLUSIONS
  Higher homocysteinemia was predominantly observed in men, presenting low HDL-C, and at advancing age. Methylenetetrahydrofolate reductase and methionine synthase polymorphisms did not contribute to risk assessment in diabetic and non-diabetic subjects presenting normal folate levels.
authors.affiliation: Lipids, Atherosclerosis and Vascular Biology Laboratory, Department of Medicine, Cardiology Division, Federal University of São Paulo, São Paulo, SP 04039-001, Brazil.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Helfenstein
authors.forename: Francisco A H
authors.initials: FA
authors.lastname: Fonseca
authors.forename: Waldir G M
authors.initials: WG
authors.lastname: Relvas
authors.forename: Andreza O
authors.initials: AO
authors.lastname: Santos
authors.forename: Maria L
authors.initials: ML
authors.lastname: Dabela
authors.forename: Simone C P
authors.initials: SC
authors.lastname: Matheus
authors.forename: Vânia
authors.initials: V
authors.lastname: D'Almeida
authors.forename: Sérgio
authors.initials: S
authors.lastname: Tufik
authors.forename: Fernanda G
authors.initials: FG
authors.lastname: Souza
authors.forename: Paula R
authors.initials: PR
authors.lastname: Rodrigues
authors.forename: Rosely
authors.initials: R
authors.lastname: Taglieri
authors.forename: Eder F
authors.initials: EF
authors.lastname: Sousa
authors.forename: Maria C O
authors.initials: MC
authors.lastname: Izar
mesh_terms: D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000235:genetics*; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000150:complications*; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D012044:Regression Analysis
chemical_list: D006710:Homocysteine; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase