The Steno Opti-Bolus-Timing Studies (OBT Studies)

Steno Diabetes Centers

Status: Not yet enrolling

Conditions: Type 1 Diabetes (T1D)

Treatments: Other: Low glyceamic index meal; Other: High glyceamic index meal

Study type: Interventional

Funder types: Other

Identifiers

NCT07021690

Copenhagen University Hospital

Details and patient eligibility

About

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.

Enrollment: 40 estimated patients

Sex: All

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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40 participants in 6 patient groups

Start high-GI

Active Comparator group

Description:

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

Treatment:

Other: High glyceamic index meal

Pre high-GI

Experimental group

Description:

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

Treatment:

Other: High glyceamic index meal

Post high-GI

Experimental group

Description:

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

Treatment:

Other: High glyceamic index meal

Pre low-GI

Experimental group

Description:

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

Treatment:

Other: Low glyceamic index meal

Start low-GI

Experimental group

Description:

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

Treatment:

Other: Low glyceamic index meal

Post low-GI

Experimental group

Description:

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

Treatment:

Other: Low glyceamic index meal