The Steno Opti-Bolus-Timing Studies

NCT ID: NCT07021690

Last Updated: 2025-06-15

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 40 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-06-30
• Study Completion Date: 2027-06-30

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.

Conditions

Type 1 Diabetes (T1D)

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Start high-GI

T=0: having already rested for 30 min, the participant continues to rest T=15: meal bolus for high GI meal, meal starts T=30: meal ends

Group Type: ACTIVE_COMPARATOR

High glyceamic index meal

Intervention Type: OTHER

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.

Pre high-GI

T=0: meal bolus for high GI meal T=15: meal starts T=30: meal ends

Group Type: EXPERIMENTAL

High glyceamic index meal

Intervention Type: OTHER

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.

Post high-GI

T=0: having already rested for 30 min, the participant continues to rest T=15: meal starts T=30: meal ends T=45: meal bolus for high GI meal

Group Type: EXPERIMENTAL

High glyceamic index meal

Intervention Type: OTHER

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.

Pre low-GI

T=0: meal bolus for low GI meal T=15: meal starts T=30: meal ends

Group Type: EXPERIMENTAL

Low glyceamic index meal

Intervention Type: OTHER

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.

Start low-GI

T=0: having already rested for 30 min, the participant continues to rest T=15: meal bolus for low GI meal, meal starts T=30: meal ends

Group Type: EXPERIMENTAL

Low glyceamic index meal

Intervention Type: OTHER

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.

Post low-GI

T=0: having already rested for 30 min, the participant continues to rest T=15: meal starts T=30: meal ends T=45: meal bolus for low GI meal

Group Type: EXPERIMENTAL

Low glyceamic index meal

Intervention Type: OTHER

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.

Interventions

High 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.

Intervention Type: OTHER

Low 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.

Intervention Type: OTHER

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Steno Diabetes Center Copenhagen

OTHER

Sponsor Role: lead

Responsible Party

Kirsten Nørgaard

MD, DMSc

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Kirsten Nørgaard, Professor

Role: PRINCIPAL_INVESTIGATOR

Steno Diabetes Center Copenhagen Clinical Translational Research, Diabetes Technology

Locations

Steno Diabetes Center Copenhagen Clinical Translational Research, Diabetes Technology

Herlev, , Denmark

Countries

Denmark

Central Contacts

Karen Rytter, RN, PhD

Role: CONTACT

karen.rytter@regionh.dk

+45 39680800

Ajenthen Ranjan, MD, PhD

Role: CONTACT

ajenthen.ranjan@regionh.dk

+45 39680800

Other Identifiers

Copenhagen University Hospital

Identifier Type: -

Identifier Source: org_study_id