Cross-sectional study of the association between age-related macular degeneration and arthritis in the National Health and Nutrition Examination Survey 2005-2008

Objective To explore the association between age-related macular degeneration (AMD) and arthritis in a representative sample of the US population. Design Population-based, cross-sectional study. Setting The National Health and Nutrition Examination Survey (NHANES) 2005-2008. Participants A total of 4813 participants aged 40 years and older with available information on AMD and arthritis in the 2005-2008 NHANES. Methods The status and types of arthritis were obtained from questionnaires. Non-mydriatic fundus photographs were collected. The types of AMD were assessed using the modified Wisconsin Age-Related Maculopathy Grading Classification Scheme. The association between arthritis and AMD was evaluated using logistic regression models. Results After adjusting for covariates, participants with any or early AMD had significantly lower odds of having any type of arthritis (any AMD: OR=0.56, 95% CI: 0.36-0.86; early AMD: OR=0.55, 95% CI: 0.34-0.88) or osteoarthritis (OA) (any AMD: OR=0.43, 95% CI: 0.26-0.71; early AMD: OR=0.44, 95% CI: 0.25-0.76) compared with those without AMD. When considering AMD as the outcome, significant negative associations were also found between any arthritis or OA and any (any arthritis: OR=0.64, 95% CI: 0.43-0.94; OA: OR=0.52, 95% CI: 0.33-0.82) or early AMD (any arthritis: OR=0.61, 95% CI: 0.40-0.93; OA: OR=0.51, 95% CI: 0.31-0.86) in the multivariable logistic models. There was no significant association between different types of arthritis and late AMD. Conclusions People with arthritis, especially those with OA, were less likely to have AMD compared with those without arthritis and vice versa. Further studies are needed to confirm this potential protective effect of arthritis and/or arthritis treatment on AMD and to explore the underlying mechanisms.