Spironolactone for Reducing Proteinuria in Diabetic Nephropathy

Spironolactone for reducing proteinuria and progression of renal failure in diabetic nephropathy

Introduction:

Diabetic nephropathy is the leading cause of ESRD in USA now and accounts for 40% of all new patients that begins renal replacement therapy each year. The number of new patients starting chronic dialysis therapy is 70,000 each year and is increasing. This number does not include patients who decline dialysis therapy or die soon after starting dialysis. The economic and human cost of diabetic nephropathy is therefore enormous.

Aggressive control of blood pressure especially with ACE-inhibitor had been shown to reduce proteinuria and progression of renal dysfunction in both type 1 and type 2 diabetics. Use of ACE-inhibitor reduced proteinuria even in normotensive diabetics with microalbuminuria. However even with optimal use of ACE-Inhibitor the progression of renal dysfunction is not completely stopped. Other additional treatment strategies therefore need to be explored.

Studies in animals and small pilot studies in humans have shown that nondihydropyridine calcium channel blockers (e.g. diltiazem or verapamil) may have additional protective effect in reducing proteinuria when used in conjunction with ACE-inhibitor. Use of angiotensin receptor blockers along with ACE-inhibitors also had been tried but results are not dependable because of the short sample size.