Serum levels of macular carotenoids in relation to age-related maculopathy

Background It has been hypothesized that the macular carotenoids, lutein and zeaxanthin, may protect against age-related maculopathy. We evaluated the association between blood concentrations of lutein (L) and zeaxanthin (Z) and age-related maculopathy (ARM) in a case-control analysis of the baseline examination of the Muenster Ageing and Retina Study (MARS). Methods Of the 1060 participants aged 59–82 years at baseline, 910 (85.9%) with bilateral gradable fundus photographs and complete data for the carotenoids and potential confounders were included. The Rotterdam classification system was used for definition of ARM stages. Multivariate linear regression methods were applied to model the relationship between macular carotenoids and the presence of ARM. Results The participants’ mean age was 70.9+5.5 years, 59.9% were female, 20.8% had a normal bilateral fundus, and 48.5% showed signs of early ARM (uni- or bilateral) and 30.7% of late ARM (in at least one eye). In study participants with L and/or Z supplementation (15.6%), the median serum levels for L (Z) were approximately 2 times (1.5 times) higher than in subjects with no supplementation. After exclusion of subjects with L and/or Z supplementation, no statistically significant bivariate relationship was observed between the serum levels of L or Z and the presence of ARM. Multivariate regression models, adjusting for age, gender, smoking, body-mass index, and HDL-cholesterol blood levels, produced adjusted mean serum levels of 0.124, 0.112, and 0.131 μg/ml for L and 0.019, 0.020, and 0.022 μg/ml for Z in subjects with normal fundus, early ARM, and late ARM, respectively. Conclusion In this large study, the serum concentrations of L and Z were not related to the prevalence of ARM. However, the large proportion of study participants taking L and/or Z supplementation may have affected these results.