Effects of additive therapy with spironolactone on albuminuria in diabetes mellitus: A pilot randomized clinical trial

Early diagnosis of albuminuria and the prevention of its progression to macroalbuminuria and diabetic nephropathy are crucial. Angiotensin converting enzyme inhibitors (ACEIs) and antagonists of angiotensin II receptors type I (ARBs) are currently used as first-line treatment for albuminuria in these patients. The present study was conducted to assess the efficacy of addition of spironolactone to ACEIs or ARB in the prevention of diabetic nephropathy. Sixty patients were selected from the patients who referred to a Diabetes Clinic in this randomized clinical trial study. The control group received enalapril and the case group took additive therapy with spironolactone for 12 weeks. Blood pressure, concentrations of creatinine and albumin in the serum and urine, urinary albumin/creatinine ratio, serum potassium were determined for each patient in the beginning of and every 4-6 weeks until the end of the study. This clinical trial was registered in the Iranian Registry of Clinical Trials (www.irct.ir) with registration number ID: IRCT201105084849N2. There was statistically significant difference in albumin/creatinine ratio between the two groups (p<0.001). Albuminuria reduced more significantly in case group compared to control group. It was measured 66.6±26.8 mg/mmol and 45.7±19 mg/mmol in control and case groups, respectively. The patients did not develop any significant adverse effect including reduction in GFR, hyperkalemia, and hypotension. Low to moderate doses of spironolactone can augment the effect of ACEIs in the prevention of diabetic nephropathy.