SUN-525 - Impact of Glucagon Like Peptide 1 Receptor Agonist Therapy on Glycemic Outcomes, Body Composition, and Insulin Requirements in Adults with Long Standing Type 1 Diabetes.

Background
Despite advances in insulin delivery and glucose monitoring, many adults with long-standing type 1 diabetes mellitus (T1DM) continue to struggle with excess weight, visceral adiposity, insulin resistance, and high insulin requirements. The use of GLP-1 receptor agonists (GLP-1 RA) as adjunct therapy in T1DM is increasing in clinical practice; however, long-term real-world data remain limited.

Objective
To assess metabolic, glycemic, and insulin-related outcomes over 12 months following initiation of GLP-1 receptor agonist therapy in adults with long-standing T1DM.

Methods
This retrospective real-world cohort study included 33 adults (≥18 years) with long-standing type 1 diabetes mellitus (26 females, 7 males; mean age 31.6 years) who initiated GLP-1 receptor agonist therapy. Two patients were receiving concomitant SGLT-2 inhibitor therapy, while the remainder were treated with insulin and GLP-1 RA alone. Clinical and body composition data were collected at baseline, 3, 6, and 12 months. Outcomes included anthropometric measures, body composition parameters, HbA1c, total daily insulin dose, and basal insulin dose. Paired comparisons between baseline and follow-up were performed, with statistical significance set at p< 0.05

Results
During 12 months of follow-up, patients demonstrated progressive and clinically relevant reductions in body weight (−13.0%), BMI (−12.4%), body fat mass (−18.1%), and visceral fat (−18.5%). Glycemic control improved, with mean HbA1c decreasing from 9.35% at baseline to 8.2% at 12 months (−12.3%, p=0.007). Insulin requirements were substantially reduced, with total daily insulin dose decreasing by approximately 50% (−49.7%), alongside comparable reductions in basal insulin dose. Changes in lean body mass and skeletal muscle mass were modest and did not reach statistical significance.

Conclusion
In routine clinical practice, GLP-1 receptor agonist therapy was associated with meaningful improvements in adiposity, glycemic control, and insulin requirements among adults with long-standing T1DM. These findings suggest a potential role for GLP-1 RA as an adjunct to insulin therapy in carefully selected patients and highlight the need for larger prospective studies.

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