Effects of Folic Acid on Renal Endothelial Function in Patients with Diabetic Nephropathy: Results from a Randomized Trial

Endothelial dysfunction has been shown to promote podocyte injury and albuminuria in diabetes, highlighting the importance of the interaction between renal endothelial cells and podocytes. Folic acid (FA) improves nitric oxide synthase (NOS) function and ameliorates progression of diabetic nephropathy in animal models. We tested whether high-dose FA treatment improves renal endothelial function and albuminuria in human subjects with incipient diabetic nephropathy. Following a double-blind, randomized cross-over design, 28 patients with type 2 diabetes and albuminuria were allocated to 4-weeks treatment with placebo and high-dose FA (5 mg/day). Renal NO production determined as response of renal plasma flow (RPF) to NOS inhibition with N(G)-monomethyl-L-arginine (4.25 mg/kg i.v.), renal oxidant stress as the response of RPF to vitamin C infusion (3mg/kg) and albuminuria were determined after each treatment phase. Neither the reduction of RPF to L-NMMA nor the increase of RPF to vitamin C infusion differed between treatment phases (ΔRPF to L-NMMA: -74±71 ml/min/m2 during placebo versus -63±56 ml/min/m2 during FA, P=0.57; ΔRPF to vitamin C: +93±118 ml/min/m2 versus +94±108 ml/min/m2; P=0.70). In line with the lack of effect on the renal endothelium, albuminuria was not affected by FA treatment (110±179 mg/day during placebo versus 87±146 mg/day during FA; P=0.12). High-dose FA treatment does not improve renal ...
Source: Clinical Science - Category: Biomedical Science Authors: Source Type: research