Introduction: Sodium-glucose cotransporter 2 inhibitor (SGLT2i) is a medication for type 2 diabetes mellitus (T2DM). Some reports showed SGLT2i improved insulin resistance, however, the effect on insulin resistance is not well established. Hepatic insulin clearance (HIC) is new pathophysiology of T2DM. The effect of SGLT2i on hepatic insulin clearance and insulin resistance is not well known. We investigated the effect of SGLT2i on insulin resistance, insulin secretion, incretins, body composition, and hepatic insulin clearance.
Materials and Methods: We conducted a meal tolerance test (MTT), and the hyperinsulinemic-euglycemic clamp in 9 T2DM patients. 50 mg/day ipragliflozin was admitted, MTT and clamp were performed after 4 months. We calculated the postprandial C-peptide AUC to insulin AUC ratio as the HIC. We also measured GLP1, GIP, and glucagon levels during MTT.
Results: Body weight, HbA1c, and body composition were not significantly changed after 4 months of treatment. Postprandial glucose, fasting, and postprandial insulin were significantly decreased. The insulin resistance of the glucose clamp was not changed, but HOMA-IR and insulin sensitivity index (ISI) were significantly improved. Incretins and glucagon were not changed. Hepatic insulin clearance was significantly increased, but whole-body insulin clearance was not changed. Fib 4 index and fatty liver index were significantly reduced. HOMA-beta and insulinogenic index was not changed but the C-peptide index was significantly increased.
Conclusions: Although patients’ number was small, these results suggest that SGLT2i treatment decreased hepatic insulin resistance, increased hepatic insulin clearance, and decreased hyperinsulinemia, it might protect beta-cell function.