EFFECTS OF ANTIHYPERTENSIVE THERAPY ON PROGRESSION OF DIABETIC NEPHROPATHY

There is a clear relationship between hypertension and the microvascul ar complications of diabetes. Genetic predisposition to hypertension h as been correlated to the risk of diabetic nephropathy in type I diabe tes, and hypertension is a well known risk factor for developing nephr opathy in patients with type II diabetes. Multiple studies have emphas ized the importance of hypertension on renal disease progression, and blood pressure control with conventional antihypertensive drugs slows the rate of renal function loss in diabetic nephropathy. Furthermore, evidence of the role of renin-angiotensin system (RAS) on progression of renal damage has focused much interest on the therapeutic action of the RAS blockade. In patients with type I diabetes, blocking the RAS with angiotensin converting enzyme (ACE) inhibitors prevents progressi on from microalbuminuria to overt nephropathy, and in overt nephropath y decreases the gradual loss of renal function beyond its blood pressu re lowering effect. Less clinical information is available in type II diabetic nephropathy, but our experience and some recent studies sugge st that ACE inhibitors also have a renoprotective action in type II di abetes. The role of calcium channel blockers in diabetic nephropathy i s not clear. Several short-term studies with the first generation dihy dropyridine calcium antagonists showed a lower effect on urinary album in excretion and a more rapid progression to renal failure than with A CE inhibitors. However, other calcium channel blockers, particularly o f the non-dihydropyridine type, have been shown to have a beneficial e ffect on diabetic nephropathy, decreasing proteinuria and slowing prog ression.