725-P: Reducing Hypoglycemic Risk during Postprandial Exercise with Closed-Loop Insulin Delivery in Adults with Type 1 Diabetes: Announced and Unannounced Exercise

Background: Exercise-induced hypoglycemia is a major barrier for physical activity practice. Compared to conventional insulin therapy, closed-loop (CL) insulin delivery reduces hypoglycemic risk during post-absorptive exercise but has not been studied during postprandial exercise. Methods: Randomized crossover trial comparing 3 strategies for a postprandial (PP) exercise (90 min after breakfast) at 60% of VO2peak for 60min: 1) Unannounced exercise (Unann); 2) Announced exercise with reduced insulin bolus (Ann+RB): increased glucose target combined with a 33% meal bolus reduction); 3) Announced exercise with full bolus (Ann+FB): increased glucose target combined with usual meal bolus in 37 adults with type 1 diabetes. Results: Median percentage time spent in hypoglycemia (