title: Relation of plasma folate and methylenetetrahydrofolate reductase C677T polymorphism to colorectal adenomas.
abstract: BACKGROUND
  Folate intake may be related to decreased risk of colorectal cancer and adenomas. Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in folate metabolism. We examined the relation between plasma folate status and colorectal adenomas with reference to effect modification by the genetic polymorphism (C677T) of MTHFR.
  
  
  METHODS
  Study subjects were middle-aged Japanese men: 177 cases of colorectal adenomas and 192 controls with normal total colonoscopy. Statistical adjustment was made for hospital, rank in the Self Defense Forces, alcohol use, smoking, and body mass index.
  
  
  RESULTS
  Plasma folate levels were slightly lower in adenoma cases than in controls. Adjusted odds ratio (OR) for high (>5.50 ng/ml) versus low plasma folate levels was 0.72 (95% CI: 0.46-1.14). As compared with subjects with the CC or CT genotype having low plasma folate levels, those with the TT genotype showed a decreased risk of colorectal adenomas when they had high levels of plasma folate (adjusted OR = 0.58, 95% CI: 0.21-1.61), and an increased risk when they had low folate levels (adjusted OR = 2.13, 95% CI: 0.82-5.54). There was no clear relation between plasma folate and colorectal adenomas among those with the CC or CT genotype.
  
  
  CONCLUSIONS
  The findings suggest an interaction between folate and the MTHFR genotype on colorectal adenomas.
authors.affiliation: Department of Preventive Medicine, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan. marugame@phealth.med.kyushu-u.ac.jp
authors.forename: Tomomi
authors.initials: T
authors.lastname: Marugame
authors.forename: Emiko
authors.initials: E
authors.lastname: Tsuji
authors.forename: Chikako
authors.initials: C
authors.lastname: Kiyohara
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Eguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Oda
authors.forename: Koichi
authors.initials: K
authors.lastname: Shinchi
authors.forename: Suminori
authors.initials: S
authors.lastname: Kono
mesh_terms: D000236:Adenoma / Q000097:blood / Q000235:genetics*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000097:blood / Q000235:genetics*; D005492:Folic Acid / Q000097:blood* / Q000378:metabolism; D005838:Genotype; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D016017:Odds Ratio; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics* / Q000378:metabolism; D011110:Polymorphism, Genetic; D012306:Risk
chemical_list: D005492:Folic Acid; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)