Obesity-associated insulin resistance is correlated to adipose tissue vascular endothelial growth factors and metalloproteinase levels

Our aim was to analyze and compare angiogenic factor expression levels in both subcutaneous (SC) and omentum (OM) adipose tissues from morbidly obese patients (n = 26) with low (OB/L-IR) (healthy obese) and high (OB/H-IR) degrees of IR, and lean controls (n = 17). Another objective was to examine angiogenic factor correlations with obesity and IR.Here we found that VEGF-A was the isoform with higher expression in both OM and SC adipose tissues, and was up-regulated 3-fold, together with MMP9 in OB/L-IR as compared to leans. This up-regulation decreased by 23% in OB/-H-IR compared to OB/L-IR. On the contrary, VEGF-B, VEGF-C and VEGF-D, together with MMP15 was down-regulated in both OB/H-IR and OB/L-IR compared to lean patients. Moreover, MMP9 correlated positively and VEGF-C, VEGF-D and MMP15 correlated negatively with HOMA-IR, in both SC and OM.We hereby propose that the alteration in MMP15, VEGF-B, VEGF-C and VEGF-D gene expression may be caused by one of the relevant adipose tissue processes related to the development of IR, and the up-regulation of VEGF-A in adipose tissue could have a relationship with the prevention of this pathology.The prevalence of obesity has increased dramatically in the last decades and is now considered a major health problem. In fact, the current epidemic of obesity has been suggested as the leading cause for the decreased life expectancy forecast for the next generation. Obesity is very often accompanied by other diseases, the most common being type 2 diabetes mellitus (T2DM) and cardiovascular complications [1-3].T2DM and obesity both involve genetic and environmental factors. However, progression to overt diabetes in patients with obesity is not clearly predicted. Likewise, while some obese individuals progress to T2DM, others only have mild metabolic abnormalities suggesting that the absolute amount of fat stored may not be the most important factor in determining the relationship between obesity and T2DM [4-7].Adipose tissue expand