1860-P: Impact of Physical Activity on the Night Outcomes with the DBLG1 System

Introduction and Objective: Physical activity (PA) increases insulin sensitivity in people with T1D, elevating nocturnal hypoglycemia risk. We evaluated the safety and efficacy of the DBLG1 System during the night following declared PA compared to nights following days without PA. Methods: We analyzed real-world data from 2,322 adults (61% female, median age 42 years, median HbA1c 7.4%). We compared 17,666 nights (12:00 PM-6:00 AM) following a PA session to matched control nights from non-PA periods (shifted 24/48 hours prior). Dependent variables included Time Below Range (TBR 70 mg/dL), Time in Range (TIR 70-180 mg/dL), total insulin delivery and rescue carbohydrate intake (RC). Differences were assessed using paired t-tests and Cohen’s d for effect size. Results: Nocturnal safety was equivalent between groups (Table 1): TBR remained identical at 1.07% (p=0.937). This stability was achieved through automated insulin reduction (-0.2 IU; p0.001) rather than increased carbohydrate intake, as RC remained stable (2.5g vs 2.6g; p=0.47). TIR was maintained at a high level (81.3% vs 81.8%), with a negligible effect size (Cohen’s d = -0.019). Conclusion: The DBLG1 System effectively manages post-exercise nocturnal hypoglycemia risk. The algorithm successfully adapts to increased insulin sensitivity by modulating delivery rather than relying on additional rescue carbohydrates, ensuring that nights following activity are as safe as nights following sedentary periods. Disclosure A. Adenis: Employee; Current; Diabeloop SA. S. Lachal: Employee; Current; Diabeloop SA. P. Gauthier: Employee; Current; Diabeloop SA. P. Gimenez: Employee; Current; Diabeloop SA. C. Desir: Employee; Current; Diabeloop SA. T. Le Roux-Mallouf: None. E. Huneker: Employee; Current; Diabeloop SA. P.Y. Benhamou: Employee; Current; Diabeloop SA. Advisory Panel; Ended; Eli Lilly and Company, Novo Nordisk.