title: Plasma Homocysteine, Serum Folic Acid, Serum Vitamin B12, Serum Vitamin B6, MTHFR, and Risk of Normal-Tension Glaucoma.
abstract: BACKGROUND
  This meta-analysis aims to comprehensively evaluate the association between total homocysteine (tHcy) levels, serum folic acid, vitamin B12, vitamin B6 levels, methylenetetrahydrofolate reductase (MTHFR) C677T genotype, and risk of normal-tension glaucoma (NTG).
  
  
  METHODS
  A systematic search of the EMBASE and PubMed databases was performed to evaluate plasma tHcy levels, serum folic acid, B vitamins' mean difference, and odds ratios of MTHFR C677T genotype between cases and controls.
  
  
  RESULTS
  A total of 7 studies including 458 cases and 555 controls meeting the inclusion criteria were involved in this meta-analysis. There were 4 studies for tHcy (149 cases and 148 controls), 2 studies for vitamin B6, vitamin B12, and folate (90 cases and 82 controls), and 4 studies for MTHFR (343 cases and 449 controls). Overall, the mean plasma tHcy levels, serum folic acids, vitamin B12, and vitamin B6 levels were 1.16 μmol/L [95% confidence interval (CI), -0.13, 2.45], -0.62 μmol/L (95% CI, -1.98, 0.74), 5.81 μmol/L (95% CI, -3.53, 15.14), and -16.79 μmol/L (95% CI, -86.09, 52.51). MTHFR TT genotype was found to be unrelated to NTG risk (odds ratio=1.08; 95% CI, 0.69, 1.69).
  
  
  CONCLUSIONS
  NTG is not associated with elevated plasma tHcy, serum folic acid, serum vitamin B12, serum vitamin B6, and MTHFR C677T genotype.
authors.affiliation: *Department of Ophthalmology, Sun Yat-Sen Memorial Hospital †Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, P.R. China.
authors.forename: Jinmiao
authors.initials: J
authors.lastname: Li
authors.forename: Fan
authors.initials: F
authors.lastname: Xu
authors.forename: Rui
authors.initials: R
authors.lastname: Zeng
authors.forename: Haijun
authors.initials: H
authors.lastname: Gong
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Lan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005492:Folic Acid / Q000097:blood*; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007429:Intraocular Pressure; D057066:Low Tension Glaucoma / Q000097:blood* / Q000188:drug therapy / Q000235:genetics*; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D014805:Vitamin B 12 / Q000097:blood*; D025101:Vitamin B 6 / Q000097:blood*; D014815:Vitamins / Q000097:blood
chemical_list: D014815:Vitamins; D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12