EFFECT OF TROGLITAZONE ON MICROALBUMINURIA IN PATIENTS WITH INCIPIENTDIABETIC NEPHROPATHY

OBJECTIVE - Although some studies have suggested a direct action of tr oglitazone on vascular cells, its effects on diabetic vascular disease s have not been reported. We therefore investigated the effect of trog litazone on microalbuminuria in patients with incipient diabetic nephr opathy. RESEARCH DESIGN AND METHODS - A total of 30 patients with type 2 diabetes associated with microalbuminuria (urinary albumin-to-creat inine ratio [ACR] [milligrams per gram creatinine] ranging from 30 to 300 mg/g creatinine) were studied. They were randomly divided into two groups: patients treated with metformin (500 mg/day, n = 13) or with troglitazone (400 mg/day, n = 17) for 12 weeks. ACR, lipid profile, bl ood pressure, glycated hemoglobin, and plasma glucose during meal-load tests were measured every 4 weeks. RESULTS - Anthropometric indices ( BMI and percent fat), lipid profile, and blood pressure did not change with either treatment. Fasting and postmeal glucose levels decreased similarly in the two groups. Decrements in glycated hemoglobin were gr eater in the metformin group at 4 and 8 weeks after the initiation of treatment (P < 0.05). Troglitazone reduced ACR (median [25-75th percen tiles]) from 70 (49-195) to 40 (31-90) mg/g creatinine at 4 weeks (P = 0.021) and maintained these reduced levels throughout the treatment p eriod (8 weeks: 35 [26-68], P = 0.007; 12 weeks: 43 [26-103], P = 0.04 7). Metformin did not change ACR throughout the 12 weeks. CONCLUSIONS - Troglitazone ameliorated microalbuminuria in diabetic nephropathy. F urthermore, our findings suggest that troglitazone has some effects on vascular cells other than lowering plasma glucose levels. Troglitazon e might be useful for diabetic angiopathy, including nephropathy and c oronary artery disease.