The effect of rosiglitazone on urine albumin excretion in patients with type 2 diabetes mellitus and hypertension.

Background: Thiazolidinediones are antidiabetic agents that improve insulin sensitivity (IS). Accumulating data indicate that these agents provide beneficial effects beyond glycemic control, such as improvement in vascular function. The aim of this study was to determine the effect of rosiglitazone on urine albumin excretion (UAE) in patients with type 2 diabetes mellitus (DM) and hypertension.

Methods: The study involved 20 subjects with type 2 DM who were already on 15 mg glibenclamide daily but were achieving poor glycemic control and who had either poorly controlled or newly diagnosed hypertension. In these patients, rosiglitazone (4 mg daily) was added to the existing therapeutic regimen for 26 weeks. At baseline and the end of the treatment, subjects gave a 24-h urine collection for direct measurement of albumin and a spot specimen for determination of the albumin-to-creatinine ratio (ACR). Subjects also had a hyperinsulinemic euglycemic clamp and an ambulatory blood pressure (BP) monitoring.

Results: At the end of the study, UAE was significantly reduced versus baseline, as measured either directly in the 24-h collection (22.4 +/- 4.6 v 13.8 +/- 3.0 mg/day, P < .05) or with ACR (20.9 +/- 3.8 v 14.0 +/- 2.8 mg/g, P < .05). The percentage changes in UAE (DeltaALB for the 24-h collection and DeltaACR for ACR) correlated with the respective changes in IS (r = -0.64, P < .01 for DeltaALB and r = -0.48, P < .05 for DeltaACR), systolic BP (r = 0.63, P < .01 and r = 0.58, P < .01 respectively), and diastolic BP (r = 0.56, P < .05 and r = 0.50, P < .05 respectively).

Conclusions: In this study, treatment of type 2 diabetic hypertensive patients with rosiglitazone significantly decreased UAE. Lowering of BP and improvement of IS should play roles in this UAE reduction.