The Effect of Pioglitazone on Adiposity, Adiponectin and Carotid Artery Intimal Thickness in Obese but Otherwise Healthy Minority Subjects

We examined the hypothesis that the PPAR Gamma activator, Pioglitazone, has a fat depot specific effect and aimed at determining the ef fects of pioglitazone on changes in total and regional fat distribution, serum adiponectin levels, carotid artery intimal thickness, and subcutaneous adipose tissue histology in otherwise healthy obese men and women from a minority population.

Materials and Methods: This is a doubleblind, randomized, controlled trial, single site study of the minority population in south central Los Angeles. Thirtyfive obese, but otherwise healthy, men and women (waisttohip ratio >0.95 for men and >0.85 in women) were randomly assigned into three groups: Group A: placebo; group B, pioglitazone 30 mg/day, and group C, pioglitazone 45 mg/day, for a duration of 6 months. The primary outcome measures were changes in visceral fat as measured by Computerized Tomography scan (CT Scan) of the abdomen and thigh, body composition by Dual energy Xray Absorptiometry Scan (DXA scan) and carotid artery intimamedia thickness as measured by ultrasound. Serum adiponectin levels and the size and number of adipocytes were also measured.

Results: At baseline, mean age, proportion of female participation, race and ethnicity distribution, blood pressure, Body Mass Index (BMI) and anthropometric measures of subjects in the three groups were not statistically different. After 6 months, we observed significant decrease of intramuscular fat and significant increase of subcutaneous thigh fat in groups B and C as compared to group A. The average carotid artery intimal thickness increased in group A (p<0.01), but not in group B, and decreased in group C (p<0.01). Serum adiponectin levels rose sharply (p<0.001) in the treatment groups only. A significant positive correlation was observed between the change of the adiponectin levels and subcutaneous thigh fat. Conclusion: Results of this study supports the use of pioglitazone in the prevention of stroke and peripheral vascular disease in highrisk populations.