Gealekman O, Guseva N, Gurav K et al.
University of Massachusetts, Worcester, MA, USA.
Editor’s note: Growth of adipose tissue is coordinated between capillary growth and dynamic modification of the extracellular matrix. Since insulin resistance in obese humans has been associated with reduced capillary density and alterations in capillary size, appropriate microcirculation is important for adequate adipose tissue function. Thiazolidinediones have been shown to mitigate insulin resistance by improving tissue perfusion, and they may also facilitate the formation of new adipocytes. Therefore, the authors of this study examined whether thiazolidinediones favorably affect adipose tissue vascularization in humans. To this end, 35 participants (body mass index 25–43 kg/m2) with normal glucose tolerance were randomized to receive a thiazolidinedione (rosiglitazone) or placebo for 6 weeks. Assessments of adipocyte size and capillary density, as measured by immunohistochemistry, and angiogenic potential, as measured by capillary sprout formation, were performed at the end of the study.