Pancreatic fat accumulation is associated with decreased β-cell function and deterioration in glucose tolerance in Korean adults

Aims: This study was designed to investigate the association between pancreatic fat content (PFC) and insulin secretory capacity as well as glucose tolerance in Korean adults. Materials: A total of 39 participants (mean age 49.9 years, 53% males) without a previous history of diabetes, or those previously diagnosed as having diabetes but with less than 10 years of disease duration and no medication history were included. They were stratified according to the results of the oral glucose tolerance test (OGTT): normal glucose tolerance, prediabetes, and diabetes. Methods: All participants underwent the proton magnetic resonance spectroscopy (¹H-MRS) to assess PFC. Insulin sensitivity and β-cell function were measured by the frequently sampled intravenous glucose tolerance tests (FSIVGTT) and OGTT-derived indices. Results: As glucose tolerance deteriorated, parameters such as Stumvoll index, oral glucose insulin sensitivity index, homeostatic model assessment (HOMA)-β, insulinogenic index and oral disposition index from the OGTT, and acute insulin response to glucose (AIR) and disposition index (DI) from the FSIVGTT were decreased. PFC increased with deterioration in glucose tolerance (NGT: 12.0%, prediabetes: 23.7%, and diabetes: 31.9%). Correlation analysis indicated that glucose levels at 60 and 120 min during the OGTT were positively correlated with PFC. Also, there was a significant negative correlation between PFC and DI as well as AIR derived from the FSIVGTT. Conclusions: PFC evaluated by ¹H-MRS in Korean adults was higher in those diagnosed with diabetes than those with normal glucose tolerance status. PFC also showed a significant negative correlation with indices reflecting beta cell function.