Real-world evaluation of insulin requirements after GLP1 agonist or SGLT2 inhibitor initiation and titration

PURPOSE: To describe insulin adjustments made following initiation of glucagon-like peptide 1 agonist (GLP1a) or sodium-glucose cotransporter-2 inhibitor (SGLT2i) therapy in patients within a primary care setting. METHODS: This was a multicenter, retrospective cohort study conducted at an academic health system. Adults with type 2 diabetes mellitus initiated on a GLP1a or SGLT2i while on insulin and managed by an ambulatory care pharmacist were included. The primary endpoint was the percent change in total daily insulin dose at specified time points (2 weeks, 4 weeks, 6 weeks, 3 months, and 6 months) after agent initiation. The secondary endpoints included a glycosylated hemoglobin (HbA1c) value of less than 8%, change from baseline HbA1c, and safety profiles of GLP1a therapy and SGLT2i therapy. RESULTS: Of the 150 patients included, 123 were initiated on a GLP1a and 27 on an SGLT2i. After 6 months, GLP1a initiation had resulted in a mean 23.5% decrease (P < 0.001) in insulin dosage and SGLT2i resulted in a mean 0.2% increase (P = 0.20). Insulin dosage reduction with GLP1a use was significantly different between baseline and each time point (P < 0.001). About 72% of patients initiated on a GLP1a and 59% of those initiated on an SGLT2i achieved an HbA1c value of less than 8%. The mean absolute change from baseline in HbA1c concentration was -1.7% with GLP1a use and -1.5% with SGLT2i use (P < 0.001 for both comparisons with baseline values). Hypoglycemia occurred in 21% of patients on a GLP1a and 11% of those on an SGLT2i. CONCLUSION: After GLP1a initiation, the mean total daily insulin dose decreased by 23.5%; after SGLT2i initiation, insulin requirements increased by a mean of 0.2%. These results will help guide insulin adjustments after initiation of these medications.