Prospective randomized controlled study for the therapeutic effect of removing uremic toxins on endothelial function in undialyzed patients with chronic renal failure

INTERVENTION: Treated by AST‐120 6g daily for a period of 6 months Not treated by AST‐120 for a period of 6 months CONDITION: Undialyzed patients with chronic renal failure PRIMARY OUTCOME: Flow‐mediated vasodilation of branchial artery SECONDARY OUTCOME: Changes of the below parameters:; (1) Systolic and diastolic blood pressure; (2) Creatinine clearance (Ccr); (3) Urinary protein excretion (UPE); (4) Mediators associated with endothelial function INCLUSION CRITERIA: (1) Medications have not been changed in the last 6 months. (2) Blood pressures have been controlled appropriately in the last 6 months. (3) HbA1c levels have been stable within +/‐0.5% changes in the last 6 months. (4) Over 20 years of age. (5) Patients with the informed consent to this study.