Purpose
To determine the association between age-related macular degeneration and plasma levels of C-reactive protein.
Methods
This cross-sectional study included 5418 participants in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2008, ≥ 40 years of age, who were diagnosed with or without age-macular degeneration (AMD) and had laboratory determination of C-reactive protein level (CRP). Information regarding demographics, co-morbidities, and health-related behavior such as smoking were obtained.
Results
CRP levels were divided into four categories based on the risk for cardiovascular diseases. Those with less than 0.05 mg/dL were considered normal, low risk was considered for levels between 0.05 and 1 mg/dL, moderate risk from 1 to 2 mg/dL and high risk was grater than 3 mg/dL. Participants diagnosed with AMD had higher levels of CRP 0.583 mg/dL (SEM 0.74%) than those without 0.435 mg/dL (SEM 0.15%). A multivariate regression model shows that individuals with higher values for CRP have a greater risk for having AMD (odds ratio [OR] 3.11, 95% confidence interval [CI] 1.10-8.75; P=0.032). We also observed a trend showing that increasing levels of CRP are significantly related with AMD.
Conclusions
Our results demonstrate that higher levels of CRP were significantly associated with high odds for having AMD. This could indicate that individuals with high risk for cardiovascular disease also have a higher risk for developing AMD.
Keywords: 464 clinical (human) or epidemiologic studies: risk factor assessment •
412 age-related macular degeneration