Muscle and intra-pancreatic fat deposition in relation to glucose metabolism in individuals at high risk for type 2 diabetes

Abstract Aims/hypothesis We investigated the association between multi-organ ectopic fat and glucose metabolism in individuals at high risk for type 2 diabetes. We aimed to better understand subclinical alterations in insulin secretion and sensitivity, and their relation to intra-pancreatic and postural muscle fat while adjusting for hepatic fat. Methods This cross-sectional study included 80 individuals with a BMI between 23 and 40 kg/m 2 and at least one metabolic alteration: increased fasting triglycerides or insulin, plasma glucose, HbA 1c and/or high waist circumference. Participants underwent abdominal MRI and a 3 h 75 g OGTT. Ectopic fat in the liver, pancreas and psoas and paraspinal muscles was quantified using mDIXON. Insulin sensitivity, insulin secretion and pancreatic beta cell function were determined with the oral minimal model. Results The median age of participants was 56 (IQR 39–64) years and 63% were women. Pancreatic fat fraction and paraspinal muscle fat fraction did not correlate with glucose metabolism indices. Psoas muscular fat fraction was negatively associated with static insulin secretion ( r = − 0.23, p = 0.04) and static disposition index ( r = − 0.23, p = 0.04) and positively associated with HOMA2-IR ( r = 0.25, p = 0.03), independent of age, sex and BMI. The associations did not remain significant when adding hepatic fat as a covariable. Conclusions/interpretation These results suggest that intra-pancreatic and postural muscle fat are not associated with insulin secretion and resistance in individuals at risk for type 2 diabetes. Liver fat could be a main contributor of early risk for type 2 diabetes development.