Increased HbA1c relative to actual glycemic control in patients treated with sodium–glucose cotransporter 2 inhibitors

AIMS/INTRODUCTION: Among patients with diabetes receiving sodium-glucose cotransporter 2 (SGLT2) inhibitors, HbA1c levels are higher than glycated albumin levels. This study therefore aimed to evaluate the discrepancy between HbA1c and glucose management indicator (GMI), an index of glucose management derived from continuous glucose monitoring, in this population. MATERIALS AND METHODS: This multicenter retrospective cohort study included patients with diabetes in whom HbA1c and GMI were simultaneously measured at two Japanese institutions. Data were collected when HbA1c levels had stabilized for at least 6 months after the administration of an oral hypoglycemic agent. The primary outcome was the discrepancy between HbA1c and GMI among patients receiving SGLT2 inhibitors and those receiving other oral hypoglycemic agents. Inverse probability of treatment weighting (IPTW) was used to adjust for confounding factors. RESULTS: In total, 136 patients were included; of these, 109 and 27 were included in the SGLT2 inhibitor group and control group, respectively. After IPTW adjustment, the discrepancy between HbA1c and GMI (HbA1c-GMI) was significantly higher in the SGLT2 inhibitor group than in the control group (β = 0.42; 95% confidence interval 0.14-0.70; P = 0.003). CONCLUSIONS: Patients receiving SGLT2 inhibitors may have increased HbA1c relative to their actual glycemic control.