Elevated homocysteine linked with macular degeneration risk
In the largest study of its kind to date, researchers at the Massachusetts Eye and Ear Infirmary and Devers Eye Institute in Portland, Oregon discovered that having a high level of homocysteine is associated with an increased risk of developing age-related macular degeneration (AMD). Homocysteine is an amino acid that, when elevated in the blood, is a biomarker for cardiovascular disease. The findings were published in the January issue of the American Journal of Ophthalmology.
Massachusetts Eye and Ear Infirmary director of epidemiology Johanna M. Seddon, MD and colleagues measured fasting plasma homocysteine in 934 participants in the Age-Related Eye Disease Study (AREDS). Five hundred and forty seven men and women diagnosed with age-related macular degeneration and 387 subjects without the disease were included in the current analysis.
The team found that median homocysteine levels were higher among those with advanced macular degeneration than in those without the disease or with mild AMD. Additionally, homocysteine levels over 12 micromoles per liter, which are considered to be high, were associated with increased macular degeneration risk. The authors propose several reasons for homocysteine's influence on increasing the risk of macular degeneration, including oxidative injury to endothelial cells, increased peroxidation of low-density lipoprotein and altered blood clotting mechanisms.
Dr Seddon summarized, "We found that elevated homocysteine in the blood may be another biomarker for increased risk of AMD. Homocysteine can be reduced by dietary intake of vitamins B6, B12, and folate, so the relationship between this amino acid and AMD deserves further study."