Redefining Glucose thresholds for Hypo Treatment in Children with Type 1 Diabetes on Closed loop Therapy

The study aims to determine if reducing the cut-off of initiating treatment will be an acceptable hypoglycaemia threshold and will not be associated with an increase in time spent in hypoglycaemia <3.0 mmol/L with worsening of glycaemic outcomes. A two-treatment, two-period cross-over randomised controlled non-inferiority trial design will be used. Participants will be randomised to sequence A (‘Standard Hypo Rx First’), or sequence B (‘Revised Hypo Rx First’). ‘Standard Hypo Rx First’ participants will use the standard hypo treatment (i.e. Hypoglycaemia treatment initiated with glucose level <3.9 mmol/L) for 4 weeks (Period 1) after which they will switch to revised hypo treatment plan for 4 weeks (Hypoglycaemia treatment initiated at lower revised threshold of less than or equal to 3.6 mmol/L) (Period 2). The revised hypo treatment plan will consist of the same hypo treatment as clinically recommended (i.e. 10-15g of fast-acting carbohydrates, or 5.0-7.5g of fast-acting carbohydrates if on closed loop therapy) and does not change between the two arms. ‘Revised Hypo Rx First’ participants will start with revised hypo treatment plan for 4 weeks (Period 1) and cross over to standard hypo Rx plan for 4 weeks (Period 2). The 4-week duration is chosen to capture adequate number of hypoglycaemic episodes. Most children are expected to experience at least 2 or more episodes per week. There will be a wash-out phase of at least 2 weeks to prevent carryover effects. Participants will be randomised to one of the two treatment sequences using https://sealedenvelope.com/ into a) Standard Hypo Rx First’ or b) Revised Hypo Rx First’. All participants will receive weekly review with email/phone calls by our team to ensure adherence and address any concerns or questions participants may have. If time spent <3.0 mmol/L has doubled from baseline and/or is >1%, research staff (doctor and research diabetes educator) will review the participant to ensure 1) if they are ‘true’ hypoglycaemic events 2) explore the reason if ‘true’ hypoglycaemic. Adherence to hypo management will be monitored using a participant Logbook that asks for the date and time the hypo occurred, the glucose level (in mmol/L), the amount of carbohydrates given as treatment, and whether they are in the revised or standard treatment plan arms at the time of the hypo occurring. Potential participants will be identified from the Western Australian Children’s Diabetes Database by a Child and Adolescent Health Service employee and invited via email to partake in this study. Participants must attend the Diabetes Clinics at Perth Children’s Hospital to be eligible.