Pioglitazone protects HDL2&3 against oxidation in overweight and obese men

Abstract

Background The worldwide epidemic of obesity is a major public health concern and is persuasively linked to the rising prevalence of diabetes and cardiovascular disease. Obesity is often associated with an abnormal lipoprotein profile, which may be partly negated by pioglitazone intervention, as this can influence the composition and oxidation characteristics of low-density lipoprotein (LDL). However, as pioglitazone's impact on these parameters within high-density lipoprotein (HDL), specifically HDL2&3, is absent from the literature, this study was performed to address this shortcoming. Methods Twenty men were randomized to placebo or pioglitazone (30 mg/day) for 12 weeks. HDL2&3 were isolated by rapidultracentrifugation. HDL2&3-cholesterol and phospholipid content were assessed by enzymatic assays and apolipoprotein AI (apoAI) content by single-radial immunodiffusion. HDL2&3 oxidation characteristics were assessed by monitoring conjugated diene production and paraoxonase-1 activity by spectrophotometric assays. Results Compared with the placebo group, pioglitazone influenced the composition and oxidation potential of HDL2&3. Specifically, total cholesterol (P < 0.05), phospholipid (P < 0.001) and apoAI (P < 0.001) were enriched within HDL2. Furthermore, the resistance of HDL2&3 to oxidation (P < 0.05) and the activity of paroxonase-1 were also increased (P < 0.001). Conclusions Overall, these findings indicate that pioglitazone treatment induced antiatherogenic changes within HDL2& 3 , which may help reduce the incidence of premature cardiovascular disease linked with obesity.