AT1 receptor antagonists: a challenge for ACE inhibitors in diabetic nephropathy

Due to its hemodynamic, metabolic and growth promoting effects, angiotensin II (AII) may play an important role in the pathogenesis of diabetic kidney disease. Consequently, decreasing the production or cellular action of AII is a rational target for therapeutic attempts aimed at slowing the progression of diabetic nephropathy. Based on their superior renoprotective performance in recent landmark studies, currently ACE inhibitors are the drugs of choice in diabetic patients with microalbuminuria or overt proteinuria. A new class of antihypertensive medications, the AT1 receptor antagonists may represent an alternative to ACE inhibitors in the treatment of diabetic nephropathy. They provide a more complete blockade of the renal renin-angiotensin system and are generally better tolerated than ACE inhibitors. On the other hand, AT1 receptor antagonists do not increase bradykinin levels, an effect that may contribute to the high level of renoprotection achieved by ACE inhibitors. Although human data are not available at this point, ACE inhibitors and AT1 receptor antagonists have similar beneficial effects on proteinuria, renal hypertrophy and glomerulosclerosis in animal models of diabetic kidney disease. Currently several prospective studies are being conducted to compare the efficacy of ACE inhibitors and AT1 receptor antagonists in the treatment of human diabetic nephropathy.