Le tissu adipeux : un acteur majeur du syndrome inflammatoire de l'obésité ?

The concept of the existence of a low grade chronic inflammation during human obesity, which can play a role in the physiopathology of the disease and its complications, has been the subject of intense investigations for a few years. The number of molecules linked to inflammation (acute phase inflammation proteins, interleukins, cytokines) whose circulating concentrations are increased in obese subjects, does not cease rising. Weight loss generally involves a reduction of these inflammatory factors in blood circulation. Recent work showed that white adipose tissue (WAT) expresses many pro and anti-inflammatory molecules and probably contributes to increasing their circulating levels in obese subjects. Cellular and histological studies showed that the genes of inflammation are expressed within WAT by cells that are not adipocytes but constitute the “stroma vascular fraction”, in particular by the macrophages infiltrating in a substantial way adipose tissue during obesity. This review aims at synthesizing the knowledge on the inflammation in human obesity and focuses on the mechanisms of macrophage infiltration in WAT and its local and systemic consequences.