The Effect of N-Acetylcysteine on Proteinuria and Markers of Tubular Injury in Non-Diabetic Patients with Chronic Kidney Disease

Abstract

BACKGROUND: Inhibition of the renin-angiotensin-aldosterone system with angiotensin-converting enzyme inhibitors (ACEI) and/or angiotensin II subtype 1 receptor antagonists (ARB) constitutes a strategy in the management of patients with chronic kidney disease. There is still no optimal therapy which can stop the progression of chronic kidney disease. Antioxidants such as N-acetylcysteine (NAC) have been reported as a promising strategy in this field. METHODS: In a placebo-controlled, randomized, open, 2-period cross-over study, we evaluated the influence of NAC (1,200 mg/day) added to renin-angiotensin-aldosterone system blockade on proteinuria and surrogate markers of tubular injury and renal fibrosis in 20 non-diabetic patients with proteinuria (0.4-6.36 g/24 h) with normal or decreased kidney function (estimated glomerular filtration rate 61-163 ml/min). Subjects entered the 8-week run-in period during which the therapy using ACEI and/or ARB was established with blood pressure below 130/80 mm Hg. Next, patients were randomly assigned to 1 of 2 treatment sequences: NAC/washout/placebo or placebo/washout/NAC. Clinical evaluation and laboratory tests were performed at the randomization point and after each period of the study. RESULTS: No significant changes in laboratory tests were observed. CONCLUSION: NAC had no effect on proteinuria, surrogate markers of tubular injury or renal fibrosis in non-diabetic patients with chronic kidney disease.