Attenuation of Weight Loss Through Improved Antilipolytic Effect in Adipose Tissue Via the SGLT2 Inhibitor Tofogliflozin

Abstract Context Although calorie loss from increased urinary glucose excretion continues after long-term treatment with sodium-glucose cotransporter 2 inhibitors (SGLT2is), the mechanisms of the attenuated weight loss due to SGLT2is are not well known. Objective To examine the mechanism of the attenuated weight loss during long-term treatment with an SGLT2i, tofogliflozin, focusing on the antilipolytic effect of insulin on adipose tissue. Design and Participants An integrated analysis was performed using data from two phase 3 studies of 52 weeks of tofogliflozin administration. The antilipolytic effect was evaluated using adipose tissue insulin resistance (Adipo-IR) calculated from the product of the levels of fasting insulin (f-IRI) and fasting free fatty acids (f-FFAs). Results Data from 774 patients with type 2 diabetes (mean age, 58.5 years; glycosylated hemoglobin, 8.1%; body mass index, 25.6 kg/m2; estimated glomerular filtration rate, 83.9 mL/min/1.73m2; 66% men) were analyzed. Weight loss plateaued between weeks 24 and 52 after decreasing significantly. f-IRI levels decreased significantly from baseline to week 24, and the decrease was maintained until Week 52. f-FFA levels significantly increased, peaked at week 24, then declined from weeks 24 to 52. Adipo-IR levels declined progressively throughout the 52 weeks (−3.6 mmol/L·pmol/L and −6.2 mmol/L·pmol/L at weeks 24 and 52, respectively; P < 0.001 baseline vs weeks 24 and 52 and week 24 vs week 52). Higher baseline Adipo-IR levels were independently associated with greater weight loss at week 52. Conclusion The improved antilipolytic effect in adipose tissue may attenuate progressive lipolysis, leading to attenuating future weight loss induced by an SGLT2i in patients with type 2 diabetes. Cause of attenuated weight loss after lengthy treatment with tofogliflozin was studied. Adipose tissue insulin resistance declined progressively, possibly attenuating weight loss in type 2 diabetes.