title: Are the associations between life-style related factors and plasma total homocysteine concentration different according to polymorphism of 5,10-methylenetetrahydrofolate reductase gene (C677T MTHFR)? A cross-sectional study in a Japanese rural population.
abstract: Mild hyperhomocysteinemia is one of the known strong risk factors for atherosclerotic diseases, and therefore it is important to clarify factors that could determine plasma total homocysteine (tHcy) level. A cross-sectional study with a random sample of 455 Japanese rural residents aged 40-69 years was conducted in 2000 to investigate the associations of plasma tHcy concentration with 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and selected life-style related factors. The frequency of the mutant allele, Valine (V) allele, was 0.40 and the prevalence of VV genotype was 14.3%. Plasma tHcy concentration in VV was significantly higher than those in two other genotypes. There were significant inverse associations of plasma tHcy with serum folate and serum vitamin B12 (P<0.001 for trend, respectively); both being stronger in VV than in other genotypes. The number of cigarettes smoked per day was positively associated with plasma tHcy concentration. A multivariate regression analysis revealed that serum folate, serum vitamin B12, and MTHFR genotype were independently associated with plasma tHcy. The inter-individual variance of plasma tHcy was more explained by serum folate and vitamin B12 than by MTHFR genotype. Higher intakes of folate, vitamin B12, and non-smoking may be important to prevent mild hyperhomocysteinemia and the eventual atherosclerotic diseases in this Japanese rural population.
authors.affiliation: Department of Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, Japan.
authors.forename: Htay
authors.initials: H
authors.lastname: Lwin
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Chigusa
authors.initials: C
authors.lastname: Date
authors.forename: Nobuo
authors.initials: N
authors.lastname: Yoshiike
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kokubo
authors.forename: Heizo
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000483:Alleles; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008297:Male; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D011110:Polymorphism, Genetic; D012044:Regression Analysis; D012307:Risk Factors; D012424:Rural Population; D011795:Surveys and Questionnaires
chemical_list: D006710:Homocysteine; D000587:Oxidoreductases Acting on CH-NH Group Donors