Effect of spironolactone on urinary protein excretion in patients with chronic kidney disease.

AIM: To investigate antiproteinuric effect of spironolactone in patients with chronic kidney disease (CKD) treated with angiotensin-converting enzyme (ACE) inhibitors and/or angiotensin II type 1 receptor blockers (ARBs).

METHODS: This study was performed in 33 CKD patients with proteinuria. 24 h urinary protein excretion and biochemical parameters were obtained before the therapy. Then, spironolactone (25 mg/d) was added to the therapy. The antiproteinuric effect of spironolactone was examined for eight weeks.

RESULTS: At eight weeks, there was a significant decrease in proteinuria (p < 0.001, 47.9% decrease). Systolic and diastolic blood pressures were significantly decreased (p < 0.004, p < 0.001, respectively). However, no correlation was detected between the reductions in systolic and diastolic BP and the reduction in proteinuria (p = 0.464, p = 0.239, respectively). Serum potassium level increased significantly (p < 0.001).

CONCLUSIONS: Our study suggests that spironolactone significantly reduces urinary protein excretion. This strategy may be useful to slow the progression of CKD. However, hyperkalemia is the most important side effect of treatment, and it is necessary to monitor potassium level. Further studies are needed to determine the efficacy of spironolactone on proteinuria.