[Effects of rosiglitazone on endothelial function in non-diabetic subjects with metabolic syndrome]

To evaluate the effects of rosiglitazone (ROSI), an insulin-sensitizer, on endothelial function and endothelial activation markers in a group of non-diabetic subjects with metabolic syndrome.

A group of eighteen subjects (12 women, 6 men), mean age 41.2 +/- 9.7 and BMI 37.8 +/- 6.1 Kg/m2, was treated with rosiglitazone 8 mg/day for 12 weeks. Another group of nine healthy subjects, mean age 26.1 +/- 4.4 and BMI 21.7 +/- 1.7 Kg/m2, was studied at baseline to compare vasodilator response. Endothelial function was evaluated by venous occlusion plethysmography after intra-arterial infusions of acetylcholine (Ach) and sodium nitroprusside (SNP). The following were measured: glucose, insulin, lipids, fibrinogen, and high-sensitivity C-reactive protein (CRP). HOMA and Quicki indexes were calculated to quantify insulin resistance (IR).

There was an improvement in insulin resistance, as evidenced by lower HOMA-R and higher QUICKI index, as well as a decrease in CRP and fibrinogen levels. Endothelium-dependent vasodilation also improved, as evidenced by greater increment in blood flow after Ach and greater decrement in vascular resistance. No difference in endothelium-independent vasodilation was noted.

Rosiglitazone treatment reduced insulin resistance, fibrinogen, and CRP levels and improved endothelial function in non-diabetic subjects with metabolic syndrome. These data suggest that rosiglitazone plays a role in the regulation of endothelial function in patients at high cardiovascular risk.