Obesity, adipose tissue and insulin resistance

The adipose tissue of obese subjects is infiltrated by more macrophages that in normal-weigth subjects. These macrophages are probably attracted to the adipose tissue due to the death of adipocyte hipertrophy or by the secretion of proinflammatory citokynes. During obesity, the adipose tissue releases adipokines like TNF-alpha and IL-6, promoting a proinflammatory environment. The release of TNF-alpha and IL-6 is higher in visceral adipose tissue than in subcutaneous adipose tissue. Among the most commonly described adipose tissue inflammatory factors associated with insulin resistance are TNF-alpha and IL-6, which are positively correlated with adipocyte size. During obesity, the adipose tissue releases adipokines like TNF-alpha and IL-6, promoting a proinflammatory environment. The release of TNF-alpha and IL-6 is higher in visceral adipose tissue than in subcutaneous adipose tissue. Among the most commonly described adipose tissue inflammatory factors associated with insulin resistance are TNF-alpha and IL-6, which are positively correlated with adipocyte size. During obesity, there is a state of oxidative stress with high levels of reactive oxygen species, which has been defined as the link between obesity and insulin resistence which keeps the inflammatory environment due the activation of transcription factor NF-kappa B, which is involved in induced expression of the cytokine proinflammatory gene.