Closing the Loop on Exercise in Type 1 Diabetes

Background: Despite its well-established health benefits, exercise imposes challenges on glucose control in individuals with type 1 diabetes due to the complex interactions between exerciseinduced effects on glucose metabolism and exogenous insulin therapy. Although clinical guidelines for exercise management in type 1 diabetes are available, implementation is challenging in daily life. The risk of exercise-induced dysglycaemia deters many people with type 1 diabetes from participating and benefitting from exercise. Rapid progress has been made in the development of closed-loop systems, also known as the artificial pancreas. The autonomous modulation of insulin delivery in a glucoseresponsive manner by closed-loop systems may be beneficial in addressing and overcoming the risk and burden of exercise-induced dysglycaemia. Methods: A summative overview of closed-loop application during exercise in type 1 diabetes is discussed, outlining current evidence and limitations, our perspectives in the field and future outlook. Results: Outcomes from clinical studies evaluating both single- and dual-hormone closed-loop during exercise are reported. Current approaches to enhance closed-loop performance during exercise are described. Conclusion: Closed-loop system has the potential to ameliorate exercise management in type 1 diabetes. Promising results have been shown, however innovative approaches are still needed to overcome inherent limitations of closed-loop performance during exercise. Future studies in larger generalizable patient population during real-life settings are still needed, to further evaluate its clinical applicability.