Effects of troglitazone on atherogenic lipoprotein phenotype in coronary patients with insulin resistance

Insulin resistance is associated with atherogenic lipoprotein phenotype, including small dense LDL particle, hypertriglycemia and low HDL cholesterol levels. Troglitazone, a novel insulin sensitizing agent, may improve the associated lipid profile in patients with insulin resistance. We examined the effects of troglitazone (400 mg daily for 12 weeks) in 12 non-diabetic coronary patients (60±10 years), all of whom had hyperinsulinemic response to an oral glucose load. Troglitazone markedly reduced the insulin response. After the treatment, plasma triglycerides decreased by 32% (P<0.05), HDL cholesterol increased by 11% (P<0.05) and LDL peak particle diameter increased from 24.7±0.3 to 25.5±0.5 nm (P<0.01). These lipidic improvements were associated with a significant rise in postheparin lipoprotein lipase levels (175±52 to 217±69 ng/ml, P<0.01). In patients with insulin resistance syndrome, troglitazone improved the atherogenic lipoprotein phenotype as well as hyperinsulinemia. Our data suggest that troglitazone therapy could reduce the atherosclerotic risk due to insulin resistance even in non-diabetic patients.