title: Plasma homocysteine in patients with retinal vein occlusion.
abstract: OBJECTIVE
  To evaluate total plasma homocysteine (HCY) during fasting and post methionine load test (MLT), serum folate, serum vitamin B12, and methylenetetrahydrofolate reductase (MTHFR) mutation in patients with retinal vein occlusion (RVO) and to examine the association between these risk factors and 2 subtypes of RVO: central (CRVO) and branch (BRVO).
  
  
  METHODS
  This case-control study included 91 Italian patients presenting a first RVO and 71 healthy subjects, matched by age, without history of thromboembolic diseases, glaucoma, or malignancy. Homocysteine fasting and after MLT, serum folate level, serum vitamin B12 level, and other laboratory tests were assessed. Genetic analysis for the C677T MTHFR mutation was performed.
  
  
  RESULTS
  Multivariate logistic regression analysis indicated that hypertension (odds ratio [OR] 2.63; 95% confidence interval [CI] 1.30-5.30; p = 0.007), higher values of fasting HCY (OR 1.16; 95% CI 1.01-1.33; p = 0.03), and low concentrations of vitamin B12 (OR 0.99; 95% CI 0.995-0.999; p = 0.01) were independently correlated with RVO. Moreover, the main determinants for CRVO risk were hypertension (OR 2.46; 95% CI 1.06-5.72; p = 0.04), high values of fasting HCY (OR 1.20; 95% CI 1.02-1.41; p = 0.03), and low concentrations of vitamin B12 (OR 0.99; 95% CI 0.994-0.999; p = 0.008), whereas for BRVO risk only hypertension was significant (OR 2.74; 95% CI 1.24-6.03; p = 0.01). Genotype distribution of the MTHFR C677T mutation did not reveal any significant difference between patients and controls.
  
  
  CONCLUSIONS
  These results suggest that elevated fasting HCY levels, low vitamin B12 levels, and hypertension are associated with a risk of RVO, especially for CRVO. Moreover, our data suggest that only hypertension is associated with BRVO risk.
authors: DINOGMI, Laboratory of Metabolic Diseases, University of Genova, Istituto Giannina Gaslini, Genova - Italy.
authors: Giuseppe
authors: G
authors: Minniti
authors: Maria Grazia
authors: MG
authors: Calevo
authors: Alessandro
authors: A
authors: Giannattasio
authors: Paola
authors: P
authors: Camicione
authors: Ugo
authors: U
authors: Armani
authors: Renata
authors: R
authors: Lorini
authors: Gianna
authors: G
authors: Piana
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D005492:Folic Acid / Q000097:blood; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000150:complications*; D006973:Hypertension / Q000150:complications; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D008875:Middle Aged; D009154:Mutation; D020641:Polymorphism, Single Nucleotide; D012170:Retinal Vein Occlusion / Q000097:blood* / Q000209:etiology*; D012307:Risk Factors; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12