Glucose-lowering effects of semaglutide compared with dulaglutide using professional continuous glucose monitoring in outpatients with type 2 diabetes mellitus: a pilot study

Objective Currently, the most frequently prescribed once weekly glucagon-like peptide-1 receptor agonists (GLP-1RA) in Japan are dulaglutide (DG) and semaglutide (SG). However, little is known about the differences between these two compounds in clinical practice in Japan. This study compared the efficacy and safety of DG and SG using professional CGM in 12 patients attending our outpatient with poorly controlled type 2 diabetes mellitus (T2DM) while using GLP-1RA. Methods The study subjects were 12 T2DM patients with HbA1c ≥ 7.0% on treatment with 0.75 mg/week DG for at least 24 weeks. All patients wore the professional CGM twice, once while receiving DG and once when the SG dose was increased to 0.5 mg/week. Results Time in range was significantly better with SG than with DG, which was the main outcome measure. Regarding the secondary outcome measures, standard deviation of glucose, average sensor glucose, time above range, maximum sensor glucose, interquartile range, SD of glucose during the nocturnal period (0000–0559), and average nocturnal sensor glucose (0000–0559) were significantly better with SG than DG. In contrast, SG had no effect on the time below range and minimum sensor glucose compared to DG. Conclusions Switching from 0.75 mg DG to 0.5 mg SG in patients with T2DM improved glycemic variability, mean glycemic index, and daily variability without increasing the hypoglycemic index. The results suggest that switching to SG may be a useful option in patients experiencing inadequate glycemic control with DG.