Type 1 Diabetes (T1D)
Conditions
Keywords
AID system, bolus timing, Glycemic index
Brief summary
The project investigates the significance of the timing of insulin dosing for breakfast and lunch with an automated insulin pump and whether it matters if the meal primarily contains high or low glycemic index carbohydrates. We hypothesise that a bolus given 15 minutes before the meal will result in the best blood glucose levels after the meal, regardless of the type of carbohydrates. Participants will attend 6 experimental days over a maximum of 3 months, where they will be served either breakfast or lunch at the research site, depending on sub-study (breakfast or Lunch sub-study). Three different bolus timings will be tested, with either rapidly absorbed carbohydrates or slowly absorbed carbohydrates, in a randomized order for each participant. Participants will take insulin for the meal using the bolus calculator in the pump, either 15 minutes before, at the start of the meal, or 30 minutes after the meal. The development in sensor glucose will then be monitored for up to 4 hours after the meal.
Interventions
OTHERHigh glyceamic index meal
Meal sizes are standardized regarding the amount of carbohydrate, always 50 g. The composition of these meals focuses on selecting carbohydrates with high glycemic index.
OTHERLow glyceamic index meal
Meal sizes are standardized regarding the amount of carbohydrate, always 50 g. The composition of these meals focuses on selecting carbohydrates with low glycemic index.
Sponsors
Steno Diabetes Center Copenhagen
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
the study contains two sub-studies: breakfast and lunch
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
Type 1 diabetes ≥ 3 years Age 18-70 years User of the MiniMed 780G for at least 3 months Use of Novorapid insulin in the pump (for a minimum of two weeks) TIR \> 70% for minimum of 14 days Use carbohydrate counting and bolus calculation Uploads insulin pump and CGM data to the Carelink Personal database Pump settings: carbohydrate ratio (300-500 rule), active insulin time of ≤ 3 hours and smartguard target glucose of 5.5 or 6.1 mmol/L
Exclusion criteria
Use of anti-diabetic medicine (other than insulin), corticosteroids or other drugs affecting glucose metabolism during the study period or within 4 weeks prior to study start Diagnosed with gastroparesis Females who are pregnant, breast-feeding Food allergies related to standardized meals Alcohol or drug abuse Inability to understand the individual information and to give informed consent. Current participation in another clinical trial that, in the judgment of the principal investigator, will compromise the study results
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in SG between three meal bolus delivery times for meals with two levels of glycemic index | From -15 min before the meal to 270 min after meal intake | The primary objective is to compare the change in SG (from -15 min before the meal to the highest SG level measured during 0-270 min after start of meal intake) between three meal bolus delivery times for meals with two levels of glycemic index (GI) (high-GI and low-GI meals, respectively). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Difference in amount of insulin given for autocorrections during the post-meal period between the three bolus methods for each type of meal. | From -15 min before the meal to 270 min after meal intake | — |
| Distribution of Time Below Range (TBR) | From -15 min before the meal to 270 min after meal intake | Distribution of TBR in the observation period of 4 hours and 45 minutes around the meal between the three bolus methods for each GI meal. |
| Difference in the number of Time Below Range events (with SG< 3.9 mmol/l) | From -15 min before the meal to 270 min after meal intake | Difference in the number of Time Below Range (TBR) events (with SG\< 3.9 mmol/l) in the observation period of 4 hours and 45 minutes around the meal between the three bolus methods for each GI meal. |
| Area under the post-meal CGM-curve | From -15 min before the meal to 270 min after meal intake | — |
| Distribution of Time In Tight target Range (TITR) | From -15 min before the meal to 270 min after meal intake | Distribution of Time In Tight target Range (TITR), in the 4 hours and 45 minutes observation period around the meal between the three bolus methods for each GI meal. |
| Distribution of Time Above Range (TAR) | From -15 min before the meal to 270 min after meal intake | Distribution of Time Above Range (TAR), in the 4 hours and 45 minutes observation period around the meal between the three bolus methods for each GI meal. |
| Number of hypoglycemia events (PG< 3.9 mmol/L ) | From -15 min before the meal to 270 min after meal intake | — |
| Distribution of Time In target Range (TIR) | From -15 min before the meal to 270 min after meal intake | Distribution of Time In target Range (TIR) in the 4 hours and 45 minutes observation period around the meal between the three bolus methods for each GI meal. |
Countries
Denmark
Contacts
Primary ContactKaren Rytter, RN, PhD
Backup ContactAjenthen Ranjan, MD, PhD
Outcome results
None listed