Canagliflozin, a sodium glucose co-transporter 2 inhibitor, reduces post-meal glucose excursion in patients with type 2 diabetes by a non-renal mechanism: results of a randomized trial

OBJECTIVE: Canagliflozin is a sodium glucose co-transporter 2 inhibitor approved for treating patients with type 2 diabetes. This study evaluated renal and non-renal effects of canagliflozin on postprandial plasma glucose (PG) excursion in patients with type 2 diabetes inadequately controlled with metformin. MATERIALS/METHODS: Patients (N=37) were randomized to a four-period crossover study with 3-day inpatient stays in each period and 2-week wash-outs between periods. Patients received Treatments (A) placebo/placebo, (B) canagliflozin 300 mg/placebo, (C) canagliflozin 300 mg/canagliflozin 300 mg, or (D) canagliflozin 300 mg/canagliflozin 150 mg on Day 2/Day 3 in one of four treatment sequences (similar urinary glucose excretion [UGE] expected for Treatments B-D). A mixed-meal tolerance test (MMTT) was given 20 minutes post-dose on Day 3 of each period. RESULTS: A single dose of canagliflozin 300 mg reduced both fasting and postprandial PG compared with placebo, with generally similar effects on fasting PG and UGE observed for Treatments B-D. An additional dose of canagliflozin 300 mg (Treatment C), but not 150 mg (Treatment D), prior to the MMTT on Day 3 provided greater postprandial PG reduction versus placebo (difference in incremental glucose AUC0-2h, -7.5% for B vs A; -18.5% for C vs A; -12.0% [P = 0.012] for C vs B), leading to modestly greater reductions in total glucose AUC0-2h with Treatment C versus Treatment B or D. Canagliflozin was generally well tolerated. CONCLUSIONS: These findings suggest that a non-renal mechanism (ie, beyond UGE) contributes to glucose lowering for canagliflozin 300 mg, but not 150 mg.