GLP-1 Receptor Agonists in Overweight and Obese Individuals With Type 1 Diabetes Using an Automated Insulin Delivery Device: A Real-World Study

Introduction: Automated insulin delivery (AID) systems have improved glycemic control in individuals with type 1 diabetes (T1D) but overweight and increased cardiovascular risk remain a challenge. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are associated with improved cardiometabolic profile but are currently not approved for the treatment of T1D. Material and methods: Individuals with T1D at Steno Diabetes Center Copenhagen, Denmark, treated with AID and off-label GLP-1 RA for at least six months between January 2017 and May 2024 were included in a retrospective chart review study. Results: Nineteen individuals with (median [range]) age 42 (24-60) years were included. At GLP-1 RA initiation, hemoglobin A1c (HbA1c) was 7.3% (6.1%-8.7%), HbA1c 56 (43-72) mmol/mol, body weight 91.5 (78.0-115.0) kg, and body mass index 35.4 (27.0-42.0) kg/m(2). Time in range was 74% (29%-82%), time above range 25% (18%-71%) while time below range was 1% (0%-5%). After six months of treatment, body weight changed -11% (-22% to -3%; P = .001) and total daily insulin dose changed -15.1 (-32.5 to -8.2) IU (P = .004). There were no significant changes in HbA1c or other glucose measures. One person developed ketoacidosis caused by infusion set failure, but none reported severe hypoglycemia. Conclusion: Glucagon-like peptide-1 receptor agonist as add-on therapy for six months in individuals with obesity and AID-treated T1D led to considerable weight loss and a reduction in insulin dose.