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.