Impact of endogenous insulin secretion on the improvement of glucose variability in Japanese patients with type 2 diabetes treated with canagliflozin plus teneligliptin

AIMS/INTRODUCTION: To identify the effect of combination therapy with a dipeptidyl peptidase‐4 inhibitor and a sodium–glucose cotransporter 2 inhibitor compared with switching from a dipeptidyl peptidase‐4 inhibitor to a sodium–glucose cotransporter 2 inhibitor on improving the glucose variability in patients with or without impaired endogenous insulin secretion. MATERIALS AND METHODS: A secondary analysis regarding the relationship between endogenous insulin secretion and the change in mean amplitude of glycemic excursions (ΔMAGE) was carried out in a multicenter, prospective, randomized, parallel‐group comparison trial that enrolled patients with type 2 diabetes who had been taking teneligliptin and were treated by switching to canagliflozin (SWITCH) or adding canagliflozin (COMB). Participants were categorized into the following four subgroups: SWITCH or COMB and high or low fasting C‐peptide (CPR) divided at baseline by the median. RESULTS: ΔMAGE in the COMB group was greatly improved independent of a high or low CPR (−29.2 ± 28.3 vs −20.0 ± 24.6, respectively; P = 0.60). However, ΔMAGE was not ameliorated in the low CPR SWITCH group, and the ΔMAGE was significantly smaller than that in the high CPR COMB group (P < 0.01). CONCLUSIONS: COMB would be a better protocol rather than switching teneligliptin to canagliflozin to improve daily glucose variability in patients with impaired endogenous insulin secretion.