Association Between Metallic Elements in Diet and Diabetic Retinopathy: A Cross-Sectional Study

Purpose: To evaluate the association between consumption of Zn, Cu, Fe, Na, K, Ca, Mg and DR in America through NHANES 2005-2008. Methods: Most representative 163 participants were consisted of 89 with DR and 74 without DR. The multivariate logistic regression was applied to estimate the correlation between consumption of these metallic elements and DR incidence rate in 3 models. And Weighted Quantile Sum (WQS) regression was used to compare the most obvious metal which influence DR risk. Finally, Restricted cubic splines (RCS) were used to investigate the potential nonlinear relationship between DR risk and zinc. Results: Participants with DR showed significantly higher zinc intake level compared to without DR (DR: 13.66±7.41, non-DR: 9.40±5.61, p=0.005). Logistic regression analysis showed a marked positive linear relationship between zinc and the incidence of DR among 7 metallic elements (OR: 1.13, 95% CI: 1.07-1.20, p < 0.001). The significant association was consistent across different adjustment models. But there were no statistically significant associations between DR and the other 6 elements. WQS regression noted that zinc take up the highest estimated weight 0.4236. RCS revealed that there is no nonlinear relationship between zinc and DR risk with p for nonlinear 0.609. Conclusion: In NHANES, participants with type 2 diabetes mellitus (T2DM) exhibiting higher dietary zinc intake demonstrated significantly increased risk of DR. And the relationship between zinc intake and DR is positive and linear.