Elevated serum homocysteine, low serum vitamin B12, folate, and age-related macular degeneration: The Blue Mountains Eye Study

PURPOSE: To assess associations between increased serum homocysteine, low vitamin B12, low folate, and age, related macular degeneration (AMD). DESIGN: Population-based, cross-sectional analysis. METHODS: Serum homocysteine, vitamin B12, and folate were measured in 2,335 participants of the Blue Mountains Eye Study second survey. AMD detected from retinal photographs included atrophic or neovascular lesions. RESULTS: After adjusting for age, gender, and smoking in logistic regression models, homocysteine > 15 mu mol/l was associated with an increased likelihood of AMD in participants aged < 75 years (odds ratio [OR] 3.21, 95% confidence interval [95% CI] 1.09 to 9.43). A similar association was found for vitamin B 12 < 125 pmol/l (OR 2.30, 95% CI 1.08 to 4.89) among all participants. In participants with homocysteine <= 15 mu mol/l, low serum B12 was associated with nearly four,fold higher odds of AMD (OR 3.74, 95% CI 1.06 to 13.24). Folate was not statistically significantly associated with AMD. CONCLUSIONS: Increased homocysteine and low vitamin B12 were independently associated with an increased risk of AMD in this study population.