Links between ectopic fat and vascular disease in humans

Abstract

The average of overweight individual can have differential fat depots in target organs or specific compartments of the body. This ectopic fat distribution may be more of a predictive factor for cardiovascular risk than obesity. Abdominal visceral obesity, a representative ectopic fat, is robustly associated with insulin resistance and cardiovascular risk. Fat depots in the liver and muscle tissue cause adverse cardiometabolic risk by affecting glucose and lipid metabolism. Pericardial fat and perivascular fat affect coronary atherosclerosis, cardiac function, and hemodynamics. Fat around the neck is associated with systemic vascular resistance. Fat around the kidney may increase blood pressure and induce albuminuria. Fat accumulation in or around the pancreas alters glucose metabolism, conferring cardiovascular risk. Ectopic fat may act as an active endocrine and paracrine organ that releases various bioactive mediators that influence insulin resistance, glucose and lipid metabolism, coagulation, and inflammation, which all contribute to cardiovascular risk. Because both obese and apparently lean individuals can have ectopic fat, regional fat distribution may play an important role in the development of cardiovascular diseases in both nonobese and obese people.

Keywords: body fat distribution; cardiovascular diseases; fatty liver; insulin resistance; intra-abdominal fat.

Figure 1

Ectopic fat storage in key target-organs or compartments contributing to atherosclerosis and cardiovascular risk

Figure 2

Mechanisms of various ectopic fats related with atherosclerosis and cardiovascular diseases (FFA, free fatty acid, ROS, reactive oxygen species, VLDL, very low density lipoprotein, TG, triglyceride, RAS, renin-angiotensin system)