Effects of 1‐year treatment with canagliflozin on body composition and total body water in patients with type 2 diabetes

Abstract Aim To characterize the long‐term changes in body composition associated with sodium‐glucose cotransporter‐2 (SGLT2) inhibitors. Materials and Methods In this multicentre, single‐arm, open‐label study, 107 patients with type 2 diabetes were treated with canagliflozin 100 mg, as add‐on therapy, for 12 months. Body composition was measured with a body composition analyser (T‐SCAN PLUS) using the impedance method to prospectively analyse changes in body components, including percentage of body fat, body fat mass, total body water, muscle mass and mineral mass. Estimated plasma volume (PV) was calculated using the Kaplan formula. Results Body weight showed a significant decrease from 1 month to 12 months of treatment with canagliflozin, with a higher rate of decrease in body fat in body composition. A significant decrease in mineral mass was also observed, but its rate was low. Following treatment with canagliflozin, changes in total body water did not affect intracellular water, and a significant decrease in extracellular water, including plasma components, was observed early and was sustained up to 12 months. Protein mass, a component of muscle mass, was not affected, with only a slight decrease in water volume observed. Conclusions Canagliflozin decreased extracellular fluid and PV in addition to decreasing fat in the body via calorie loss resulting from urinary glucose excretion. This study suggested that SGLT2 inhibitors might reduce body weight by regulating fat mass or water distribution in the body and might have cardiac and renal protective effects by resetting the homeostasis of fluid balance.