Effect of troglitazone on endothelial function in type 2 diabetic patients.

Lysophosphatidylcholine (lysoPC), a component of oxidized low-density lipoprotein cholesterol (LDL-C), has been reported to impair nitric oxide production and endothelium-dependent vasorelaxation. The effects of troglitazone (CAS 97322-87-7), which is an antidiabetic agent with antioxidant properties, on serum levels of lysoPC and nitrite/nitrate (NO x ) have been studied. Eight patients with Type 2 diabetes (non-insulin dependent diabetes mellitus, NIDDM) were studied (age: 61.5 ± 2.8 years; diabetes duration: 10.2 ± 1.6 years). They were additionally given troglitazone (200 mg once daily) since their fasting plasma glucose (FPG) and HbAlc levels had been increased in spite of conventional medications. Before and after 12 weeks of treatment with troglitazone their blood pressure, FPG, HbAlc, lipid profiles and NO x were measured. Troglitazone treatment had a slight depressor effect (decreasing the blood pressure from 133 ± 5/72 ± 3 to 127 ± 4/68 ± 1 mmHg; p < 0.05). FPG and HbAlc were significantly decreased with the therapy (181 ± 10 to 160 ± 10 mg/dl; p < 0.05 and 9.1 ± 0.6 to 8.1 ± 0.5 %; p < 0.05, respectively). In contrast, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and LDL-C were maintained within normal limits throughout the study. Although lysoPC and NO x levels were not altered, a negative correlation between lysoPC and NO x levels was observed. These results suggest that troglitazone is a beneficial agent improving FPG and HbAlc levels in NIDDM patients, while its effects on serum lysoPC and NO x levels, at least for 12 weeks, seem to be minimal.