A novel association between serum bilirubin levels and age-related macular degeneration

Abstract

The purpose of this study is to examine the association between serum bilirubin and the development of age-related macular degeneration (AMD). The study design includes the utilization of a USA-nationally representative population based cross-sectional study in the National Health and Nutrition Examination Survey: specifically, the NHANES III and continuous NHANES from years 2005-2008. 15,501 survey participants from the NHANES studies chosen for this analysis were interviewed for demographic, behavioral, and medical information, put through a comprehensive medical examination segment, and a laboratory analysis portion. The 15,501 participants were chosen based on their age (40 and above) and the presence of fundus photographs. Fundus photographs were graded using standardized protocol to diagnose early and later AMD, which were combined to form the outcome "AMD" in a binary variable. Serum bilirubin levels were measured using spectrophotometry. Of the 15,501 participants in the study, 1305 (8.9%) were diagnosed with AMD. In a multivariate logistic regression adjusted for age, sex, smoking status, race, and serum C-reactive protein (CRP) levels, bilirubin was significantly associated with AMD (odds ratio, 0.728; confidence interval, 0.547-0.969; P value, 0.0296). The findings of this study indicate that the antioxidative effects of bilirubin may play protective role in the pathology of AMD.