Abstract
Abstract: :
Background: Some cardiovascular disease (CVD) risk factors are associated with age–related macular degeneration (AMD), and high–sensitivity C–reactive protein (CRP), a systemic inflammatory marker, is associated with risk for CVD. Purpose: To test our hypothesis that the systemic biomarker, CRP, is associated with AMD (Ophthal Epidemiol 1999; 6: 125–143). Methods: Subjects were 930 participants at two Age–Related Eye Disease Study (AREDS) sites : 183 with no maculopathy, 200 with mild maculopathy, 325 with intermediate disease, and 222 with advanced AMD. Disease status was assessed by standardized grading of fundus photographs. Stored fasting blood specimens, collected for this study in 1996, were analyzed for high–sensitivty CRP levels. Logistic regression analyses were used to assess the relationship between CRP and AMD, after adjustment for other covariates. Results: CRP levels were significantly higher among advanced AMD participants compared with controls (p=.024). After adjustment for covariates including age, gender, body mass index, AREDS treatment assignment, cigarette smoking, and cardiovascular diseases, the odds ratio (OR) for the highest vs. lowest quartile of CRP was 1.65 (95% confidence interval (CI) 1.07–2.55, p for trend=.018). The OR for CRP values above the 90th percentile was 1.92 (CI 1.20–3.06).The trend for an increasing risk for intermediate and advanced AMD with higher levels of CRP was seen for both smokers and those who never smoked with an OR of 2.16 (CI 1.33–3.49) for smokers, and OR of 2.03 (CI 1.19–3.46) for never smokers, in the highest level of CRP. Conclusions: Elevated CRP level is an independent risk factor for AMD in this study. Results support the role of inflammation in the pathogenesis of AMD.
Keywords: age–related macular degeneration • inflammation • clinical (human) or epidemiologic studies: risk factor assessment