Association between dietary magnesium intake and all-cause mortality among patients with diabetic retinopathy: a retrospective cohort study of the NHANES 1999-2018

This study aimed to investigate the association between dietary magnesium intake and all-cause mortality among diabetic retinopathy (DR) patients. In this retrospective cohort study, data of 1,034 DR patients were extracted from the National Health and Nutrition Examination Survey (NHANES) (1999-2018). Dietary magnesium data were obtained from two 24-hour dietary recall interviews, and categorized into quartiles. Potential confounders were selected using weighted univariate Cox regression models. Weighted univariate and multivariate Cox regression models were used to explore the association between dietary magnesium intake and all-cause mortality in DR patients. The results were presented with hazard ratios (HRs) and 95% confidence intervals (CIs). Associations were further explored for subgroups related to age, gender, cardiovascular disease, and chronic kidney disease. Our study included 1,034 DR patients, of whom 438 (42.36%) died. The mean age of all patients was 63.26 (0.51) years old, with a median follow-up time of 75.00 months. Higher magnesium intake was associated with lower all-cause mortality risk (HR=0.58, 95% CI: 0.38-0.88) in DR patients. The association remained for those aged <65 years (HR=0.35, 95% CI: 0.15-0.81), male patients (HR=0.48, 95% CI: 0.27-0.84), patients without chronic kidney disease (HR=0.43, 95% CI: 0.23-0.82), and patients with a history of cardiovascular disease (HR=0.63, 95% CI: 0.39-1.02). DR patients with adequate magnesium intake exhibited a lower incidence of all-cause mortality. Further studies are needed to validate our findings and explore the optimal strategy for magnesium supplementation in DR patients.