Clinical trial NCT07021690: The Steno Opti-Bolus-Timing Studies
Official title: Timing Insulin for Meals Using AID Systems
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Type 1 Diabetes (T1D)
Keywords: AID system
bolus timing
Glycemic index
Lead sponsor: Steno Diabetes Center Copenhagen
Sponsor class: OTHER
First posted: 2025-06-15
Enrollment: 40
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: the study contains two sub-studies: breakfast and lunch
Primary purpose: TREATMENT

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.


Eligibility criteria: 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

Primary outcomes:
measure: Change in SG between three meal bolus delivery times for meals with two levels of glycemic index
timeFrame: From -15 min before the meal to 270 min after meal intake
Secondary outcomes:
measure: Area under the post-meal CGM-curve
timeFrame: From -15 min before the meal to 270 min after meal intake
measure: Difference in amount of insulin given for autocorrections during the post-meal period between the three bolus methods for each type of meal.
timeFrame: From -15 min before the meal to 270 min after meal intake
measure: Distribution of Time Below Range (TBR)
timeFrame: From -15 min before the meal to 270 min after meal intake
measure: Difference in the number of Time Below Range events (with SG< 3.9 mmol/l)
timeFrame: From -15 min before the meal to 270 min after meal intake
measure: Distribution of Time In target Range (TIR)
timeFrame: From -15 min before the meal to 270 min after meal intake
measure: Distribution of Time In Tight target Range (TITR)
timeFrame: From -15 min before the meal to 270 min after meal intake
measure: Distribution of Time Above Range (TAR)
timeFrame: From -15 min before the meal to 270 min after meal intake
measure: Number of hypoglycemia events (PG< 3.9 mmol/L )
timeFrame: From -15 min before the meal to 270 min after meal intake
Other outcomes:
Locations:
city: Herlev
country: Denmark
facility: Steno Diabetes Center Copenhagen Clinical Translational Research, Diabetes Technology
Study officials:
affiliation: Steno Diabetes Center Copenhagen Clinical Translational Research, Diabetes Technology
name: Kirsten Nørgaard, Professor
role: PRINCIPAL_INVESTIGATOR
References: