Obesity is a chronic multifactorial disease that has reached epidemic proportions throughout the world, as well as a relevant risk factor for diseases such as type 2 diabetes, cardiopathies, hypertension, cerebral vascular accident, osteoarthritis, polycystic ovary syndrome (PCOS), and certain types of cancer [1–3]. As a consequence obesity has become an increasing source of morbidity and mortality worldwide. In Brazil, around 38 million Brazilians over the age of 20 are overweight. Data from the Brazilian Institute of Geography and Statistics (IBGE) shows an increase in obesity among adults from both sexes [4].
Obesity is defined as the deposition of abnormal or excessive fat in the adipose tissue [5]. Adipose tissue is an endocrine organ that produces and releases a large amount of bioactive peptides called adipokines, which directly contribute to the development of metabolic abnormalities, especially insulin resistance, alterations in vascular biology and lipoprotein metabolism, and tumor development [6–8]. Among all the adipokines, IL-6, TNF-α, resistin, leptin (pro-inflammatory), and adiponectin (anti-inflammatory) have received special attention in the specialist literature.