Abstract 3974: Rapid and Direct Effect of Pioglitazone on Endothelial Function in Patients with Metabolic Syndrome
Background Pioglitazone (PIO) has been reported to improve not only insulin sensitivity but also vascular endothelial function in diabetic patients, but it remains unclear whether this beneficial vascular effect of PIO may be exerted also in non-diabetic patients and may be caused by direct effect independent of its metabolic actions or not.
Methods We investigated the short-term effects of PIO on metabolic parameters and vascular endothelial function by measuring flow-mediated dilatation (FMD) of the brachial artery on ultrasound in 30 metabolic syndrome (METS) patients without diabetes mellitus. They were randomized to either placebo group (n=15) or PIO (30 mg/day) group (n=15), and both endothelium-dependent FMD and endothelium-independent dilatation were evaluated before and 3 days after placebo or PIO treatment.
Results Treatment of either PIO or placebo did not change metabolic parameters (glucose, insulin, total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride), inflammatory markers (C-reacting protein, TNF alpha), and adiponectin within 3 days. On the other hand, PIO significantly increased FMD (P<0.001), although endothelium-independent dilatation of brachial artery was not altered.
Conclusion Short-term treatment of PIO improved vascular endothelial function in METS patients without affecting either metabolic or inflammatory status. Our data suggest that PIO has a rapid and direct vascular effect that is independent of its metabolic actions.