Evaluation of Novel Trend Arrow Adjustment Tool for Diabetes Patients Using Continuous Glucose Monitoring to Guide Insulin Bolus Adjustment (TAAT Study)

Detailed protocol: Phase 1(inpatient evaluation): This part of the study will take place in a standardized outpatient setting (CHEO Medical Day Unit/Clinic). The CGM trend arrows will be stimulated using two typical clinical scenarios: oral fast acting carbohydrate (to stimulate upward trend arrows) and exercise (to stimulate downward trend arrows). 40 participants will be enrolled in this phase of the study (20 of whom will have oral fast acting carbohydrate and 20 of whom will engage in exercise). Once trend arrows have been triggered, the subjects will receive a standardized meal, and an adjusted insulin bolus. Comparison will be made between the Trend Arrow Adjustment Tool (based on the patient's own insulin sensitivity factor) and the standard bolus adjustment recommendations (i.e. +/- 10/20%, based on the STAR 1 Trial and JDRF CGM Study Group). Phase 1 of the study will lead directly to Phase 2's outpatient evaluation. Upward CGM trend arrows (Group 1): 1. Participants will arrive fasting at the outpatient clinic. They will have been asked to change their pump and CGM the morning of the previous day and to ensure that both are functioning well prior to arrival. An iPro2 (blinded) continuous glucose monitor will be inserted subcutaneously, to provide a second recording of glucose trends. Each subject will be randomized, in a 1:1 ratio, to either the Trend Arrow Adjustment Tool (based on the patient's own insulin sensitivity factor) or the standard bolus adjustment recommendations (i.e. +/- 10/20%, based on the STAR 1 Trial and JDRF CGM Study Group). 2. Baseline blood glucose will be checked using a validated blood glucose meter, via capillary sampling. 3. At study onset, target blood glucose is 3.6-11mmol/L. If CGM shows trend arrows, the participant will proceed directly to a meal. If there are no upward trend arrows, a preliminary dose of Glucodex (oral fast acting carbohydrate) will be given. The participant will wait for up to one hour or until CGM ↑↑ are triggered, and will then proceed to a meal. 4. The participant will be given a standardized meal (containing a fixed amount of carbohydrate, fat and protein, appropriate for subject's weight) and a bolus of insulin will be given, via the insulin pump, using either the Trend Arrow Adjustment Tool or the standard 10/20% formula, to adjust the bolus dosage recommended by the bolus wizard. 5. Glucose levels will be monitored using hourly capillary blood samples, CGM and iPro2. Glucose levels \</= 3.5mmol/L or if \< 4.0 mmol/L and the subject complains of hypoglycemic symptoms, will be treated as per standard hypoglycemia management plan. 6. Glucose monitoring will continue for 3 hours postprandially, to obtain an adequate glycemic profile for examination. 7. A second dose of Glucodex will then be given, to trigger trend arrows again. Subjects will wait for one hour or until CGM ↑↑ are triggered, and will then proceed to a second standardized meal. 8. A bolus of insulin will be given, via the insulin pump, using either the Trend Arrow Adjustment Tool or the standard 10/20% formula, to adjust the bolus dosage recommended by the bolus wizard. The same bolus adjustment method will be used for both meals in the same participant. 9. Glucose monitoring will continue for a further 3 hours postprandially, to obtain an adequate glycemic profile for examination. 10. Prior to discharge, the participant and their parents/guardians, will be trained in the use of the Trend Arrow Adjustment Tool or the 10/20% bolus adjustment formula, (matching the bolus adjustment protocol used in the acute part of the study), and asked to continue to use this for the next 7 days. Participants will be requested to continue to use the iPro2 sensor for 6 days and to upload CGM data daily via Carelink Personal. A log book will be given, to record each time a trend arrow is observed and the methods used to adjust the bolus. Downward trend arrows (Group 2): 1. Subjects will arrive fasting at the outpatient clinic. An iPro2 continuous glucose monitor will be inserted subcutaneously, to provide a second recording of glucose trends. Each subject will be randomized, in a 1:1 ratio, to either the Trend Arrow Adjustment Tool (based on the patient's own insulin sensitivity factor) or the standard bolus adjustment recommendations (i.e. +/- 10/20%, based on the STAR 1 Trial and JDRF CGM Study Group). 2. Baseline blood glucose will be checked, via capillary sampling. 3. At study onset, blood glucose should be in a 6-11mmol/L target range. 4. If CGM shows trend arrows, subjects will proceed directly to a meal. 5. If there are no downward trend arrows, the participant will carry out exercise, using a treadmill. Exercise will be for a period of 15 minutes, followed by a 5 minute rest period; and repeated as tolerated until downward trend arrows are triggered. CGM will be monitored for trend arrows. Exercise will be halted if CGM shows ↓↓ or child complains of hypoglycemic symptoms. At this point, capillary blood glucose will be checked. Glucose levels \</= 3.5mmol/L, or \< 4mmol/L with hypoglycemia symptoms, will be treated according to the standard hypoglycemia management plan. 6. The participant will then be given a standardized meal (containing a fixed amount of carbohydrate, fat and protein, appropriate for the subject's weight) and a bolus of insulin will be given, via the insulin pump, using either the Trend Arrow Adjustment Tool or the standard 10/20% formula, to adjust the bolus dosage recommended by the bolus wizard. 7. Glucose levels will be monitored using hourly capillary blood samples and CGM. Any glucose levels \</= 3.5mmol/L, or \< 4mmol/L with hypoglycemic symptoms, will be treated as per standard hypoglycemia management plan. Glucose monitoring will continue for 3 hours, to obtain an adequate glycemic profile for analysis. 8. A second standardized meal will then be given. 9. A bolus of insulin will be given, via the insulin pump, using either the Trend Arrow Adjustment Tool or the standard 10/20% formula, to adjust the bolus dosage recommended by the bolus wizard. The same bolus adjustment method will be used at both time points for the participant. 10. Glucose monitoring will continue for a further 3 hours postprandially, to obtain an adequate glycemic profile for examination. 11. Prior to discharge, the participant and their parents/guardians, will be trained in the use of the Trend Arrow Adjustment Tool or the 10/20% bolus adjustment formula, (matching the bolus adjustment protocol used in Phase 1 of the study), and asked to continue to use this for the next 7days. Participants will be requested to continue to use the iPro2 sensor for 6 days and to upload CGM data daily via Carelink Personal. A log book will be given, to record each time a trend arrow is observed and the methods used to adjust the bolus. Protocol Phase 2: Outpatient Evaluation of the Trend Arrow Adjustment Tool This will be a single site, randomized, controlled, single blinded crossover study, involving the same 40 subjects. Each participant will complete a 3 week assessment. Phase 1 will lead directly into Phase 2. All subjects and their parents will have received standardized education on insulin pump therapy and CGM, with review and optimization of their basal rates, insulin sensitivity factor(s), and insulin carbohydrate ratios, during the week prior to participation in the study. For the first week of the study, subjects will administer adjusted meal insulin boluses (i.e. either the Trend Arrow Adjustment Tool, or the 10/20% bolus adjustment formula, whichever they were randomized to receive in Phase 1). In week 2, subjects will administer standard meal insulin boluses (i.e. using Bolus Wizard recommendations only; ignoring any CGM trend arrows). In week 3, subjects will crossover to the alternate arm of the study. Participants will be provided with CGM sensors for use during the study. Each participant will be asked to wear an iPro2 (blinded CGM) during the first 6 days of each week long assessment, to increase CGM data capture. A research co-ordinator will visit the participants at home to insert the iPro2 sensors, at the start of weeks 2 and 3. At the beginning of week 3, the participants and their parents/guardians will be trained in the crossover method of bolus adjustment. Participants will be given a log book and asked to record each time a trend arrow is observed (at meal times) and whether they adjusted the subsequent meal bolus, as recommended. If the adjustment was not used, they will be asked to explain why they didn't use the recommended bolus adjustment tool. Participants will be asked to upload to CareLink Personal weekly, throughout the study. Study staff will use CareLink Professional to assess glycemic variability and adherence to diabetes management. At the end of each week long assessment period, subjects will be given a questionnaire to examine their use and satisfaction with the assigned meal bolus method.