Effects of Switching from Degludec to Glargine U300 in Patients with Type 1 Diabetes Having Large Day-to-Day Glycemic Variability: A Retrospective Study

Background: Degludec (Deg) and Glargine U300 (Gla-300) are new insulin analogues with longer and smoother pharmacodynamic action than Glargine U100. Both improve glycemic variability (GV) unlike Glargine U100. However, it is not clear which insulin analogue has a better effect on GV in insulin-dependent type 1 diabetes. We evaluated the effects of switching from Deg to Gla-300 on day-to-day GV in patients with insulin-dependent type 1 diabetes treated with Deg.Methods: We conducted a retrospective study on 22 insulin-dependent type 1 diabetes patients having large day-to-day GV or frequent hypoglycemia who were treated with multiple insulin injection therapy including Deg and were advised to switch from Deg to Gla-300. We evaluated day-to-day GV and frequency of hypoglycemia in two groups. The first group included patients whose treatment was changed to Gla-300, and the second group included patients who opted to continue receiving Deg. We evaluated the change in standard deviation (SD) of fasting blood glucose (SD-FBG) calculated from self-monitoring of blood glucose (SMBG) and frequency of hypoglycemia (total, severe, and nocturnal).Results: SD-FBG and frequency of nocturnal hypoglycemia decreased in Gla-300 group compared to those in Deg group. The change in SD-FBG had a negative correlation with SD-FBG and hemoglobin A1c (HbA1c) at baseline and positive correlation with serum albumin levels at baseline in Gla-300 group. On the other hands, the change in SD-FBG had no correlation with these markers in Deg group.Conclusions: Switching from Deg to Gla-300 effectively stabilized blood glucose levels and decreased nocturnal hypoglycemia in insulin-dependent type 1 diabetes treated with Deg, especially in cases with low serum albumin, large GV, and high HbA1c.