ABSTRACT
First described as intelectin, an intestinal protein involved in the recognition of bacterial cell wall carbohydrates, human omentin is an adipokine preferentially secreted by visceral adipose tissue. Omentin expression is primarily from stromal vascular cells of adipose tissue rather than adipocytes themselves. Th e major circulating isoform in humans is omentin-1, which localizes to chromosome 1q22-q23, a region linked to increased susceptibility to type 2 diabetes. Human omentin is measurable in plasma and has also been detected in the peritoneal fl uid of some patients with ascites. Omentin is an insulin-sensitizing agent, increasing insulin-mediated glucose uptake via the phosphorylation of Akt. Omentin-l correlates negatively with fasting plasma levels of insulin and determinations of insulin resistance (HOMA), body mass index, waist circumference and leptin, a pattern similar to that seen with the insulin-sensitizing, anti-infl ammatory adipokine adiponectin. Omentin-l is positively correlated with adiponectin and HDL cholesterol, while levels are decreased in obesity and polycystic ovarian syndrome. Omentin also may play a role in infl ammation, particularly in the gastrointestinal tract, where it has been described in creeping fat associated with infl ammatory bowel disease. Omentin is emerging as an important adipokine in the regulation of glucose homeostasis, body composition, and infl ammation.
