Effects of low dose Spironolactone on proteinuria in predialysis chronic kidney disease

Objective To observe the effects of low dose Spironolactone on proteinuria and its influence about serum potassium in patients with stage 1-3 chronic kidney disease(CKD).Methods A total of 55 patients with chronic kidney disease,who were treated in our hospital from January 2010 to October 2011 were enrolled in the present study and randomly divided into two groups.The control group(27 cases) was treated based on routine therapy for CKD and Benazepril(10 mg/d) and the treatment group(28 cases) was treated with Spironolactone(20 mg/d) in addition to the therapy for the control group.24 hours urine protein excretion,systolic pressure,diastolic pressure,blood urea nitrogen(BUN),blood uric acid(BUA),serum creatinine(Scr),estimated glomerular filtration rate(GFR) and serum potassium(K+) before and after 3,6 months of treatment were measured.Results One patient in the treatment group developed hyperkalemia(K+ 6.31 mmol/L) after 1 month of treatment and withdrawed from this study.After 3 and 6 months of treatment,24 hours urine protein excretion were decreased in both treatment group and control group [Treatment group: 3 months:(1 314±302) mg/24 h vs(2 005±571) mg/24 h,P = 0.006;6 months:(1 295±426) mg/24 h vs(2 005±571) mg/24 h,P = 0.001.Control group: 3 months:(1 689±603) mg/24 h vs(2 087±636) mg/24 h,P = 0.026;6 months:(1 503±598)/24 h vs(2 087±636) mg/24 h,P = 0.012].The levels of 24 hours urine protein excretion in treatment group after 3 and 6 months of treatment were lower compared with the levels after the same period of treatment in the control group [3 months:(1 314±302) mg/24 h vs(1 689±603) mg/24 h,P = 0.033;6 months:(1 295±426) mg/24 h vs(1 503±598) mg/24 h,P = 0.027].Slightly increase of BUN and Scr and slightly decrease of eGFR were observed in both two groups after 3 and 6 months of treatment,but no statistical significance were observed.Slightly increase of serum potassium levels were observed in the treatment group after 3 and 6 months of treatment [3 months:(4.23±0.41) mmol/L;6 months:(4.27±0.50) mmol/L],but no statistical significance were observed as compared to the same group before treatment [(4.01±0.44) mmol/L] and the control group after the same period of treatment [3 months:(4.11±0.46) mmol/L;6 months:(4.16±0.43) mmol/L)].Conclusion Low dose Spironolactone may reduce proteinuria independent of the effects of blood pressure control and ACEI.More researches are needed to identify the impact of low dose Spironolactone for serum potassium level.