572-P: Identifying Insulin and Non–Insulin-Mediated Mechanisms during Physical Activity from Real-World T1D Data

Introduction and Objective: Developing a data-driven mathematical model to predict the impact of physical activity (PA) on glucose levels in individuals with T1D is non-trivial due to the concurrent insulin and non-insulin-mediated mechanisms. To understand how each mechanism affects the glucose, we performed a sensitivity analysis using the 4 most common PAs from the T1DEXI dataset. Methods: Net insulin on board (netIOB) is the change in insulin delivery relative to the basal rate in the past 4 hours. The dataset was divided into 1) positive (netIOB>0) and 2) negative (netIOB<0) netIOB at the onset of PA. For each PA, we identified a 1st-order linear time series model that predicts the glucose from the heart rate (non-insulin-mediated). Then, we analyzed how parameters change when netIOB varies. Results: We used 65 and 327 sessions of strength training for netIOB>0 and netIOB<0, 70 and 416 biking, 90 and 313 jogging, and 256 and 1072 walking, respectively. The netIOB ranged from -10 U to 10 U. Fig. 1 shows the cutoff between insulin and non-insulin-mediated effects. The parameters remain stable for netIOB<0. The model gain increases with netIOB for netIOB>0. Conclusion: Data with netIOB<0 at PA onset are representative of the non-insulin-mediated glucose uptake due to the muscle contraction based on Fig.1, while data with netIOB>0 are fundamental to identifying insulin-mediated glucose disposal. E. Aiello: Research Support; Hemsley Charitable Trust. K. Tang: Research Support; Hemsley Charitable Trust. M.P. Dhaliwal: Research Support; Hemsley Charitable Trust. R. Lal: Consultant; Abbott, Biolinq, Capillary Biomedical, Inc, Gluroo, PhysioLogic Devices, Portal Insulin, Sanofi, Tidepool. Advisory Panel; Provention Bio, Inc, Provention Bio, Inc, Microbion, Microbion, Lilly Diabetes. Research Support; Insulet Corporation, Medtronic, Tandem Diabetes Care, Inc, Sinocare Inc. C. Summers: Consultant; Tidepool. M. Connolly: Employee; Tidepool. D.P. Zaharieva: Research Support; Hemsley Charitable Trust. Speaker's Bureau; Dexcom, Inc. Research Support; Insulet Corporation, International Society for Pediatric and Adolescent Diabetes. B. Arbiter: Stock/Shareholder; Eli Lilly and Company, Dexcom, Inc. Employee; Tidepool. K. Watson: Employee; Tidepool. M. Friedman: None. L. Figg: None. A.L. Cortes-Navarro: None. I. Balistreri: None. R.S. Kingman: None. B. Suh: None. M.C. Riddell: Advisory Panel; Zucara Therapeutics, embecta. Consultant; Dexcom, Inc., Insulet Corporation, Eli Lilly and Company, Novo Nordisk. Speaker's Bureau; Novo Nordisk, Dexcom, Inc., Sanofi, Eli Lilly and Company. Stock/Shareholder; Zucara Therapeutics. Research Support; Dexcom, Inc., Insulet Corporation, Eli Lilly and Company. Y. Qin: None. The Leona M. & Harry B. Helmsley Charitable Trust Grant (2404-06905).