Circulating triacylglycerols but not pancreatic fat associate with insulin secretion in healthy humans

Background. Loss of adequate insulin secretio n for the prevailing insulin resistance iscritical for the development of type 2 diabetes and has been suggested to result fromcirculating lipids (triacylglycerols [TG] or free fatty acids) and/or adipocytokines or fromectopic lipid storage in the pancreas. This study aimed to address whether circulatinglipids, adipocytokines or pancreatic fat primarily associates with lower insulin secretion.Subjects/Methods. Nondiabetic persons (n = 73), recruited from the general population,underwent clinical examinations, fasting blood drawing to measure TG and adipocytokinesand oral glucose tolerance testing (OGTT) to assess basal and dynamic insulin secretion andsensitivity indices. Magnetic resonance imaging and1H-magnetic resonance spectroscopywere used to measure body fat distribution and ectopic fat content in liver and pancreas.Results. In age-, sex- and BMI-adjusted analyses, total and high-molecular-weightadiponectin were the strongest negative predictors of fasting beta-cell function (BCF; ? = -0.403, p = 0.0003 and ? = - 0.237, p = 0.01, respectively) and adaptation index (AI; ? = - 0.210,p = 0.006 and ? = - 0.133, p = 0.02, respectively). Circulating TG, but not pancreatic fatcontent, related positively to BCF (? = 0.375, p < 0.0001) and AI (? = 0.192, p = 0.003). Similarresults were obtained for the disposition index (DI)