Assessment of closed loop technology in young children with Type 1 Diabetes Aged 2-7 - A feasibility study

This sub-study of the HyCLIP-RCT trial assesses the feasibility of the Hybrid Closed Loop system in young children with Type 1 diabetes (T1D). It is a 6-week prospective, single-arm study with a 2-week run-in period, assessing the clinical experience of young children with T1D in free-living conditions with the Advanced Hybrid Closed Loop System (AHCL) and identifying barriers that may affect the optimal conduct of the HyCLIP-RCT study. The AHCL system comprises of the Medtronic MiniMed 780G insulin pump containing the closed loop algorithm, a next generation glucose sensor and a glucose sensor transmitter. The MiniMed 780G Pump works with the following major components: 1) Continuous Glucose Monitoring (CGM) that includes the Guardian Link (3) Transmitter that is connected to the Guardian Sensor (3) to receive sensor glucose values at 5 minute intervals; 2) blood glucose meter that will be used to calibrate the sensor and has the ability to send blood glucose values wirelessly as a convenience to the user; 3) MiniMed Mobile App to allow upload of data wirelessly to the CareLink therapy management software; and 4) Pump Accessory devices to deliver insulin (infusion sets and reservoirs). The MiniMed 780G system has the capability to operate in Manual Mode or SmartGuard Mode (also referred to as AHCL or Auto Mode). • Manual Mode is when insulin delivery is the responsibility of the user and will be based on the user defined basal rates. Meal boluses are the responsibility of the user. Manual Mode also has the capability of suspending insulin if the sensor glucose is predicted to fall below predefined threshold values (also referred to as Suspend on Low/Suspend Before Low) • SmartGuard is when the insulin delivery is being commanded by the AHCL algorithm to a set threshold of 5.5 mmol/L, 6.1 mmol/L, and 6.7 mmol/L as determined by the user. The AHCL algorithm will calculate the insulin dose at five-minute intervals, based on CGM data, in order to achieve glycaemic control throughout the day. Meal boluses are the responsibility of the user. Participants and their parents will be educated on the use of Auto Mode (which will adjust the insulin delivery based on their determined set threshold of either 5.5 mmol/L, 6.1 mmol/L, or 6.7 mmol/L) during a 2-hour pump and CGM training. The information session will cover: - Instructions for pump upload - Instructions to log hypoglycaemia and hyperglycaemia in the record book provided - Instructions to link the participant's CGM to the Medtronic 780G pump Sensor naïve individuals will have familiarisation phase of 7 to 10 days to get used to wearing a sensor. The blood glucose threshold will be set at the discretion of the participant's endocrinologist. The AHCL algorithm will calculate the insulin dose at five-minute intervals based on their continuous glucose monitoring (CGM) data, in order to achieve glycaemic control throughout the day. Participants will still need to bolus for meals like standard pump therapy; hence described as a hybrid closed loop system. The advanced algorithm will be more robust in correcting hyperglycaemia as compared to the currently available Medtronic 670G system. The modifications to the closed loop algorithm include the addition of adjustable target set points (5.5 mmol/L, 6.1 mmol/L, and 6.7 mmol/L), an auto correction bolus without user input or acknowledgement and fine tuning of safeguards in order to reduce auto mode exits and improve user experience. The system will also have an additional Bluetooth capability which will make it possible to control the glucose level via a phone app and is therefore more suitable for this young cohort. Participants will have a 2-week run-in phase (±1 week) during which participants will use the system in Manual Mode followed by a 6-week study phase (±1 week) during which AutoMode is enabled. All visits will be conducted by a Diabetes educator with the supervision of an endocrinologist. Participants will have weekly communication via phone call or email for support in between clinic visits. Glucose levels will be remotely monitored continuously 24/7 by both caregivers/parents and study staff via CareConnect App. A default urgent low setting alert will be set at 3mmol/L and caregivers/parents will be contacted by the study staff if this alert persists for more than 20 minutes (an expected recovery time following hypoglycaemia treatment). Frequency of communication will increase pas per clinical need. Adverse events, if any, will be logged at each visit.