PSUN169 Vitamin C Renal Leak in Diabetes

BACKGROUND: People with diabetes have lower plasma vitamin C concentrations compared to nondiabetic individuals. The prevalence of urinary vitamin C loss, and its relationship to plasma vitamin C concentrations are unknown. METHODS: In this cross-sectional cohort study of 162 individuals; 82 with diabetes and 80 nondiabetic controls, we investigated the prevalence and clinical characteristics of vitamin C renal leak, using fasting plasma and matched 1h urine samples. Based on vitamin C renal threshold, vitamin C renal leak was defined as presence of vitamin C in urine with plasma concentrations less than the minimal elimination threshold (MET) of 43.2µM in women or 38.1µM in men. We also assessed group differences in mean plasma vitamin C concentrations and investigated the association between diabetes-related clinical variables and renal leak. Vitamin C in plasma and urine was measured using coulometric electrochemical detection with high performance liquid chromatography. RESULTS: When compared with nondiabetic controls, subjects with diabetes had significantly increased prevalence of vitamin C renal leak (8.8% vs 32.9%: OR5, p<0.001) and decreased plasma vitamin C concentrations (53.1µM vs 40.9µM, p<0.001). Higher fasting plasma glucose, glycosylated hemoglobin A1c, body mass index, micro/macro vascular complications and protein creatinine ratio were predictive of vitamin C renal leak. CONCLUSION: Increased prevalence of vitamin C renal leak in diabetes is associated with reduced plasma vitamin C concentrations. Glycemic control, microvascular complications, obesity, and proteinuria were associated with renal leak. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.