Association between Dietary Zinc and Self-Reported Eye Affliction/Retinopathy in Individuals with Diabetes: National Health and Nutrition Examination Survey, 2007–2018

Abstract Background Emerging evidence supported that dietary zinc is beneficial for diabetes. However, few studies were available concerning the association between dietary zinc and diabetic retinopathy (DR). The present study aimed to describe the association between dietary zinc intake and the risk of DR in US adults. Methods A total of 3749 diabetic patients with self-reported eye affliction/retinopathy from the National Health and Nutrition Examination Survey (NHANES) 2007–2018 were involved. Stratified analysis by gender was performed, and logistic regression and restricted cubic spline (RCS) models were applied to assess the association between dietary zinc and DR. Receiver operating characteristic (ROC) curve was used to determine the optimal cut-off value of zinc intake for predicting DR. Results Dietary zinc was inversely associated with diabetic retinoapthy in men (OR: 0.981, 95%CI:0.965–0.997), while this trend was not significant in women. Higher quartile of dietary zinc was associated with lower occurrence of diabetic retinopathy (OR: 0.531, 95%CI: 0.334–0.846). Furthermore, increased amounts of dietary zinc was significantly associated with reduced occurrence of diabetic retinopathy (OR: 0.622, 95%CI: 0.411–0.941). ROC analysis identified a daily dietary zinc intake of 7.53 mg as the optimal cut-off value for predicting DR. Conclusion Higher levels of dietary zinc are suggested to reduce the risk of diabetic retinopathy and have been observed to have a dose-response effect in men. Assessment of dietary zinc levels may be part of the treatment of patients with diabetic complications.