ABSTRACT
Fat accumulates mainly in adipocytes of subcutaneous adipose tissue (ScAT) that is considered the “good” fat. Not all subjects with obesity have an increased risk for chronic diseases, or at least not higher than subjects without obesity with similar characteristics. The accumulation of fat as intrahepatic triglycerides (IH-TG), visceral adipose tissues (VAT), pancreatic fat, and intrathoracic adipose tissues (mediastinal, MAT and epicardial, EAT) characterizes metabolically unhealthy obesity.
Ectopic fat accumulation is associated with increased insulin resistance in the whole body (particularly in liver, muscle, and adipose tissue), impaired beta cell response, and organ dysfunction determined by the so-called cell lipotoxicity explaining why ectopic fat accumulation increases the cardiometabolic risk. It is well established that fat distribution and quality, rather than total adipose tissue, are associated with an increased risk of metabolic and cardiovascular diseases. In this chapter, the link between ectopic fat, metabolic alteration, and lipotoxicity is discussed.
