Different fat depots are distinct mini-organs

Fat tissue distribution varies widely, even among patients with the same body fat content. Visceral obesity is associated with increased risk of diabetes and atherosclerosis. Recent advances in understanding of mechanisms responsible for fat distribution patterns are reviewed. Although factors extrinsic to fat depots, including hormones, innervation, and nutrient supply, affect regional distribution, it is now evident that innate characteristics of adipose cells make an important contribution. Different fat depots are essentially distinct mini-organs. Visceral cells transfer and release fatty acids more extensively, have increased glucocorticoid and reduced thiazolidinedione responses, produce more angiotensinogen, and secrete less leptin than subcutaneous cells. Together with venous drainage through the liver and elevated intra-abdominal pressure, these features contribute to the morbidity associated with increased visceral fat mass. Once more fully understood, it may be possible to exploit regional differences in intrinsic properties of adipose cells in order to develop treatments that target specific fat depots.