Dietary Intake of Antioxidant Vitamins and Its Relation to the Progression of Chronic Kidney Disease in Adults With Preserved Renal Function

Abstract

It is expected that antioxidants contribute to slow the progression of chronic kidney disease (CKD). However, there are no data on the protective effect of dietary antioxidant vitamins on CKD. The purpose of study was to evaluate the renoprotective effect of dietary antioxidant vitamins in the general population. The study participants were 127,081 Korean adults with preserved renal function with estimated glomerular filtration rate ≥60mL/min/1.73m2. They were categorized into 3 groups by tertile levels of dietary antioxidant vitamins intake including vitamins C, E, and A. Cox proportional hazard assumption was used to calculate multivariable hazard ratios and 95% confidence interval for the incident moderate to severe CKD (adjusted hazard ratio [95% confidence interval]) according to tertile levels of dietary intake of antioxidant vitamins. Subgroup analysis was conducted to evaluate the risk of progression from normal to mildly decreased renal function, and from mildly decreased renal function to moderate to severe CKD. The risk of moderate to severe CKD was not significantly associated with the third tertile of dietary antioxidant vitamin intake including vitamin C (1.02 [0.78-1.34]), E (0.96 [0.73-1.27]), and A (0.98 [0.74-1.29]). Additionally, any tertile groups didn't show the significant association with the risk of moderate to severe CKD. Subgroup analysis also didn't show the decreased risk of progression from normal to mildly decreased renal function, and from mildly decreased renal function to moderate to severe CKD in any tertile groups. Dietary intake of vitamins C, E, and A was not significantly associated with the risk of CKD progression.