Serum Uric Acid and Intermediate Age-Related Macular Degeneration: A Nationally Representative Study in the United States.

Purpose: The purpose of this study was to investigate the associations between serum uric acid (SUA) levels and intermediate age-related macular degeneration (iAMD) in the United States population.

Methods: This study included data from the 2005 to 2008 National Health and Nutrition Examination Survey. Weighted logistic regression models (crude, partially adjusted, and fully adjusted) were used to assess linear associations between SUA levels and iAMD. Restricted cubic spline (RCS) analysis tested nonlinear associations. Subgroup analyses stratified by age, sex, and race/ethnicity further explored potential effect modifiers.

Results: Among 3208 participants aged ≥50 years, 420 (11.2%) had iAMD and 766 (22.3%) exhibited hyperuricemia (HUA). Logistic regression models showed no significant associations between SUA levels and the odds of developing iAMD across all three models. In the fully adjusted model, the odds ratio (OR) comparing the highest to the lowest SUA quintile was 0.95 (95% confidence interval [CI] = 0.53-1.70, P = 0.84). The trend test indicated no significant increase in the odds of iAMD across quintiles of SUA levels (P for trend = 0.60). Similarly, no significant association was found when SUA values were categorized as HUA or non-HUA (P = 0.66). RCS analysis did not demonstrate a nonlinear relationship between SUA levels and iAMD risk. Subgroup analyses showed no significant differences across age, sex, and race/ethnicity stratifications.

Conclusions: Elevated SUA levels were not associated with increased iAMD risk in this large, nationally representative sample.

Translational relevance: Our study provides insights into the relationship between SUA levels and iAMD, challenging "hyperuricemic AMD" and offering valuable implications for clinical risk assessment.