Abnormal Peri-Organ or Intra-organ Fat (APIFat) Deposition: An Underestimated Predictor of Vascular Risk?

Adipose tissue, a major endocrine organ, consists of brown and white adipocytes. Brown fat may play a beneficial role in cardiometabolic disorders. Brown adipose tissue can also improve glucose and lipid metabolism. In contrast, the expansion of white adipose tissue has been related to obesity, type 2 diabetes mellitus and cardiovascular disease (CVD). Both the quantity and the quality of the white adipose tissue as well as its distribution may affect CVD risk. In this context, the link between adiposity and CVD risk is greater for visceral than subcutaneous fat. Apart from these fat depots, there are other adipose tissues that are either systemically (i.e. in the liver, muscle or neck) or mainly locally acting (i.e. pericardial/epicardial, perivascular and perirenal). These fat depots can affect the nearby anatomic organs via lipid accumulation and cytokine secretion. In the present narrative review, the associations of excessive peri-organ adipose tissue, namely intrahepatic, epicardial/ pericardial, perivascular, intramuscular, peripancreatic and perirenal fat, with cardiometabolic and CVD risk factors are discussed. The effects of drugs that target vascular risk and/or different fat depots are also considered.