Visceral Fat Predicts Ectopic Fat Accumulation Mechanisms and Health Consequences

Since the late twentieth century, there has been an increasing focus on body fat distribution rather than the degree of obesity. More recently, great interest has been also focused on ectopic fat deposition in overnourished individuals. This reflects a failure in intracellular lipid homeostasis that usually prevents lipotoxicity in the organs by confining the lipid overload to white adipocytes, which are cells specifically designed to store large quantities of surplus calories. Consequently, excess body weight leads to fat infiltration of multiple organs, including the liver, pancreas, skeletal muscle, and heart, thus forming "ectopic lipid." Organ dysfunction caused by lipotoxicity and lipoapoptosis, and the different mechanisms of alteration of insulin signaling eventually lead to the main manifestations of the metabolic syndrome. Both visceral fat and ectopic fat deposition play important roles in the pathogenesis of obesity-related metabolic consequences, such as diabetes, hypertension, cardiovascular disease, and cancer.