Effects of peroxisome proliferator-activated receptor-gamma activation with pioglitazone on plasma adipokines in nondiabetic patients with either hypercholesterolemia or hypertension.

Description

This study was designed to test the hypothesis that patients with cardiovascular risk factors have altered levels of adipokines (adiponectin, leptin, resistin) that can be modified by peroxisome proliferator-activated receptor-gamma (PPAR-g) activation with pioglitazone treatment and that this effect is related to improvement in endothelial vasodilatator function. The authors verified this hypothesis in 80 patients with hypertension or hypercholesterolemia who participated in a double-blind, placebo-controlled, cross-over study. Patients received pioglitazone (45 mg/day) or placebo for 8 weeks. Twenty-two normal volunteers, matched with patients for age, gender, and body mass index, were recruited as a control group. The authors found that placebo-treated patients had lower adiponectin levels (p<0.001) and similar plasma leptin (p=0.128) and resistin levels (p=0.250) as compared to controls. This study also showed that treatment with pioglitazone significantly increased adiponectin levels (+121%, p<0.001) and decreased resistin levels (-10.5%, p=0.03). Additional analyses revealed that pioglitazone-induced changes in endothelial reactivity to acetylcholine were the only significant predictor of increases in adiponectin levels. In light of these results, the authors concluded that treatment with pioglitazone beneficially influences levels of some circulating adipokines. Moreover, the relationship between improvement in endothelial vasodilatator activity and the adiponectin increase suggests a possible link between adiponectin and vascular effects.