IDF21-0482 Hepatokine, Angiopoietin-like proteins 8 (ANGPTL8) in omental adipose tissue is positively associated with BMI

Background: Obesity defined as abnormal or excessive fat accumulation that presents major risk factors for several chronic diseases, including diabetes, cardiovascular diseases and cancer. Obesity now becomes a disease that required medical involvement. BMI has been used as a tool for the diagnosis obesity, however, some important limitations of BMI were known in individuals with normal BMI but have excessive percentage of body fatness while being labeled as non-obese subject. Therefore, in addition to BMI, more obesity-related factors or biomarkers are needed as criteria for diagnosis. Angiopoietin-like proteins 8 (ANGPTL8) is a member in the ANGPTL family and as regulator in lipid metabolism. It also plays the role in beta-cell proliferation, expansion and islet function. Serum levels of ANGPTL8 in humans were correlated with improved adipose tissue lipid storage and lower serum triglyceride levels in the fed state. But it is still unclear about correlation between expression levels of ANGPTL8 in different parts of adipose tissues and metabolic parameters. The more specific mechanisms for the regulation of ANGPTL8 on lipid and glucose metabolism still need for more investigation. Our study recruited 330 human subjects, including 281 obesity subjects and 49 non-obesity subjects. We collected the residual specimens from bariatric surgery and intra-abdominal surgery, all the participants had signed informed consent before enrolment. In this study, we found out that the ANGPTL8 level in omental adipose tissue is positively correlated with BMI. We also demonstrated that ANGPTL8 expression is significantly higher in the late stage of adipocytes differentiation than that in the early stage of adipocytes differentiation. Consistently, ANGPTL8 expression in omental adipose tissue is significantly higher in mice fed with high fat/high sucrose diet than that in normal chow diet. As our knowledge, this is the first study to demonstrate the positive association of ANGPTL8 expression in specific depot of adipose tissue with BMI and validated in both cellular and animal model of obesity. The finding indicated ANGPTL8 may be a potential biomarker of obesity.