Optimizing the combination insulin bolus split for a high‐fat, high‐protein meal in children and adolescents using insulin pump therapy

Aims To determine the optimum combination bolus split to maintain postprandial glycaemia with a high‐fat and high‐protein meal in young people with Type 1 diabetes. Methods A total of 19 young people (mean age 12.9 ± 6.7 years) participated in a randomized, repeated‐measures trial comparing postprandial glycaemic control across six study conditions after a high‐fat and high‐protein meal. A standard bolus and five different combination boluses were delivered over 2 h in the following splits: 70/30 = 70% standard /30% extended bolus; 60/40=60% standard/40% extended bolus; 50/50=50% standard/50% extended bolus; 40/60=40% standard/60% extended bolus; and 30/70=30% standard/70% extended bolus. Insulin dose was determined using the participant's optimized insulin:carbohydrate ratio. Continuous glucose monitoring was used to assess glucose excursions for 6 h after the test meal. Results Standard bolus and combination boluses 70/30 and 60/40 controlled the glucose excursion up to 120 min. From 240 to 300 min after the meal, the glucose area under the curve was significantly lower for combination bolus 30/70 compared with standard bolus ( P =0.004). Conclusions High‐fat and high‐protein meals require a ≥60% insulin:carbohydrate ratio as a standard bolus to control the initial postprandial rise. Additional insulin at an insulin:carbohydrate ratio of up to 70% is needed in the extended bolus for a high fat and protein meal to prevent delayed hyperglycaemia.