Little Loopers: A Case Series of Automated Insulin Delivery Usage with Standard and Diluted Insulin in Very Young Children with Diabetes Mellitus.

INTRODUCTION: Management of diabetes mellitus in very young children presents challenges due to variable insulin sensitivity, unpredictable carbohydrate intake, and low insulin requirements. An automated insulin delivery (AID) system addresses some of these challenges and can be used with diluted insulin where indicated. METHODS: Retrospective case series of children aged <6 years with diabetes starting CamAPS FX AID with standard (U100) or diluted (U5 or U10) insulin at a single UK clinical centre between October 2020 and April 2022. RESULTS: AID was started for seven children with diluted insulin (median interquartile range [IQR] age 1.5 [0.6, 2.8] years, mean ± standard deviation HbA1c 83 ± 18 mmol/mol) and four with standard insulin (age 4.6 [3.9, 5.4] years, HbA1c 62 ± 13 mmol/mol). AID was started at a median (IQR) of 0.2 (0.1, 0.2) months post-diagnosis in the diluted group and 17.8 (7.7, 23.6) months in the standard group. At the most recent clinic visit (9.3 ± 4.8 months after starting AID in the diluted group and 12.0 ± 2.1 months in the standard group), time in target range (3.9-10.0 mmol/L) was 66.5 ± 6.8% and 54.0 ± 5.0%, respectively. Median time in hypoglycaemia (<3.9 mmol/L) was <4% in both groups. Glucose variability was 37.5 ± 4.2% in the diluted and 43.5 ± 4.7% in the standard group. There were no episodes of diabetic ketoacidosis or severe hypoglycaemia. CONCLUSION: AID with both standard and diluted insulin can be used to safely manage diabetes in very young children with low total insulin requirements.