Pioglitazone reduces urinary podocyte excretion in type 2 diabetes patients with microalbuminuria

In various renal diseases, including diabetic nephropathy, detection of pod ocytes in the urine indicates severe injury to podocytes in the glomeruli. Pioglitazone is a newly developed antidiabetic agent that attenuates insuli n resistance. The aim of the present study was to determine whether pioglit azone affects urinary albumin excretion (UAE) or the number of urinary podo cytes or both in type 2 diabetes patients with microalbuminuria. Twenty-eig ht patients with normotensive type 2 diabetes and microalbuminuria (18 men and 10 women; mean age, 52.5 years) and 30 age-matched normotensive control s (20 men and 10 women; mean age, 51.5 years) were included in the study. U rinary podocytes were detected by immunofluorescence with a monoclonal anti body against podocalyxin. Patients were randomly assigned to 2 groups: a pi oglitazone-treatment group (30 mg/day, n = 14) and a placebo group (n = 14) . Treatment was continued for 6 months. Podocytes were absent in the urine of healthy controls, but detected in 17 of 28 diabetic patients (60.7%). UA E was reduced from 96.7 +/- 50.5 mug/min to 39.7 +/- 22.9 lig/min (P < .01) in the pioglitazone-treatment group, and the number of urinary podocytes w as reduced from 0.9 +/- 1.0 cells/mL to 0.1 +/- 0.2 cells/mL (P < .001). Ne ither UAE nor the number of urinary podocytes was affected in the placebo g roup. These data indicate that pioglitazone is effective for reducing UAE a nd podocyte injury in early-stage diabetic nephropathy. Copyright (C) 2001 by W.B. Saunders Company.