Category: Federal Forum Posters
Purpose: Treatment with insulin therapy is often limited by concerns of hypoglycemia and weight gain. The low risk of hypoglycemia and potential weight loss associated with glucagon-like peptide-1 (GLP-1) agonists and sodium-glucose cotransporter-2 (SGLT2) inhibitors suggests possible benefits when added to insulin therapy. At this time, published data directly comparing these agents is lacking. The objective of this study was to compare A1c reduction, weight loss, and changes in total daily dose (TDD) of insulin in patients with uncontrolled diabetes on insulin started on GLP-1 agonists or SGLT2 inhibitors.
Methods: A retrospective cohort study was conducted at a single VA health care system. Patients on insulin who were initiated on a GLP-1 agonist or SGLT2 inhibitor between January 1, 2014 and June 30, 2018 were analyzed. Eligible patients included those 18-89 years of age with a baseline A1c ≥8% within 1 month prior to initiation, and a follow up A1c within 20-52 weeks following initiation. Those with prior use of either class of medication within the previous 24 weeks were excluded. Endpoints assessed included HbA1c reduction, achievement of documented HbA1c goal, weight change, changes in oral antidiabetic agents, change in total daily dose of insulin, adverse drug events, and rate of discontinuations. Continuous data was evaluated using two-sided t-test and categorical data with chi-squared test. This study was approved by the institutional review board at the VA Saint Louis Health Care System.
Results: A total of 81 patients were included in this study. Fifty-five patients were initiated on GLP-1 agonists and 26 patients were initiated on SGLT2 inhibitors. GLP-1 agonists showed a non-statistically significant higher reduction in HbA1c. (1.30 vs. 1.03; p-value= 0.27). A higher percentage of patients prescribed GLP-1 agonist achieved their HbA1c goal as established by their diabetes provider (34.5% vs. 11.5%; p-value=0.03). The GLP-1 agonist group had more weight loss, but the difference did not reach statistical significance (2.40kg vs. 1.13kg; p-value= 0.22). Patients taking GLP-1 agonists had a significant reduction in TDD of insulin, while SGLT2 inhibitors had an increase in TDD of insulin and significantly higher rates of oral medications added to achieve HbA1c goal. [(TDD: -12.4% vs + 5.51% respectively; p-value= 0.01; oral medications added: 3.6% vs 19.2% respectively; p-value= 0.02)].
Conclusion: In this retrospective cohort comparing effects of GLP-1 agonists and SGLT2 inhibitors when added to insulin, GLP-1 agonists demonstrated more weight loss, larger A1c reduction, and a statistically significant larger reduction in TDD of insulin. The results of this analysis highlight the potential benefits of GLP-1 agonist compared to SGLT2 inhibitor use in patients on intensive insulin regimens.