Safely finishing a half marathon by an adult with type 1 diabetes using a commercially available hybrid closed-loop system.

Glycemic targets are often difficult to achieve in people with type 1 diabetes (T1D), especially during exercise. Consequently, many people with T1D avoid sports due to fear of hypoglycemia. Strenuous physical activity such as a half marathon imposes difficulties on people with T1D. A first commercial hybrid closed-loop (HCL) system with the potential to facilitates better diabetes management during exercise has been recently marketed. So far, no data on HCL performance during strenuous exercise has been published. A woman with well-controlled T1D participated in and safely finished a half marathon while undergoing HCL therapy. HCL could safely establish glycemic control without causing either hypo- or relevant hyperglycemia and without the need for rescue carbohydrates while running. In the days following the half marathon, there was no change in glycemic control compared to the period before. HCL use can safely manage diabetes during a half marathon in T1D.