Evaluation of spironolactone plus hydrochlorothiazide in reducing proteinuria in type 2 diabetic nephropathy.

Introduction: Inhibitors of the renin-angiotensin aldosterone system (RAAS) are the basic drugs for treatment of diabetic nephropathy, as to some extent is spironolactone. The aim of the study was to evaluate the effect of spironolactone versus spironolactone plus hydrochlorothiazide in decreasing proteinuria in type 2 diabetic mellitus (T2DM) patients.

Methods: In a double-blind clinical trial, 60 T2DM patients with nephropathy randomly assigned to three equal groups were enrolled. Spironolactone (50 mg/day) plus placebo, spironolactone (50 mg/day) plus hydrochlorothiazide (25 mg/day), and hydrochlorothiazide (25 mg/day) plus placebo were prescribed, respectively. The duration of treatment was three months for all patients. Urine protein was measured at the beginning and end of the study and analysis of data was performed.

Results: Twenty-six of the patients were male, with a total mean age of 56.8 ± 8.3 years. Mean 24-h urine protein was reduced in patients in groups 1 and 2 compared to the third group (p < 0.001). Serum potassium in the first group showed a significant increase of 0.26 meq/lit with mean 4.64 ± 0.28 meq/lit (p = 0.002), but it did not change in the second and third groups.

Conclusion: Our results showed that spironolactone plus hydrochlorothiazide is an effective and inexpensive modality in the treatment of diabetic nephropathy without increasing serum potassium.