Angiotensin II Receptor Blockers and Nephropathy Trials

This is the first of a series of reports on the American Diabetes Association (ADA) 61st Scientific Sessions held in Philadelphia in June 2001. It covers topics related to angiotensin II receptor blockers (ARBs) and nephropathy.

At a symposium at the 61st Scientific Sessions of the ADA in June 2001, the results of three recent diabetic nephropathy trials with angiotensin II subtype 1 receptor antagonists were presented. Hans-Henrik Parving, Gentofte, Denmark, pointed out that kidney disease develops in 40% of patients with type 2 diabetes, with 25% of patients in Europe and 46% in the U.S. with end-stage renal disease (ESRD) having diabetes. In the latter population, the proportion increases annually by 1.5%. In type 2 diabetes, microalbuminuria is associated with a 5–10% lifetime risk of progression to overt nephropathy, while patients with normoalbuminuria have a 10- to 20-fold lower risk. In the Irbesartan for Micro-Albuminuria in Type 2 Diabetes (IRMA) study, 590 patients with 20–200 μg/min albuminuria with normal serum creatinine and with blood pressure (BP) >135/85 mm Hg were randomized to placebo or 150 or 300 mg irbesartan daily for 2 years. The mean age was 58 years; 70% were male; all were Caucasian; baseline BP was 153/90 mm Hg; baseline albuminuria was 55 μg/min; baseline glomerular filtration rate (GFR) was 110 ml/min; and baseline HbA_1c was 7.2%. Patients treated with aspirin in a dose exceeding 325 mg daily were excluded because of the effect on proteinuria and renal function. The mean trough BP (measured 24 h after the last dose of medication) during the study was 145/84, 143/84, and 142/84 mm Hg with placebo and 150 and 300 mg irbesartan daily, respectively. Progression to macroalbuminuria occurred in 15, 10, and 5%, respectively, of the three groups at 2 years, with adjusted risk reduction of 68% with 300 mg and …