The Steno Opti-Bolus-Timing Studies

NCT07021690 | Not Yet Recruiting

• 1 other identifier: Copenhagen University Hospital
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

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)

Keywords

AID system; bolus timing; Glycemic index

Outcome Measures

Primary Outcomes (1)

• Change in SG between three meal bolus delivery times for meals with two levels of glycemic index

  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).

  From -15 min before the meal to 270 min after meal intake

Secondary Outcomes (8)

• Area under the post-meal CGM-curve

  From -15 min before the meal to 270 min after meal intake

• 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

• 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

• Distribution of Time In target Range (TIR)

  From -15 min before the meal to 270 min after meal intake

Study Arms (6)

Start high-GI

ACTIVE COMPARATOR

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

Other: High glyceamic index meal

Pre high-GI

EXPERIMENTAL

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

Other: High glyceamic index meal

Post high-GI

EXPERIMENTAL

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

Other: High glyceamic index meal

Pre low-GI

EXPERIMENTAL

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

Other: Low glyceamic index meal

Start low-GI

EXPERIMENTAL

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

Other: Low glyceamic index meal

Post low-GI

EXPERIMENTAL

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

Other: Low glyceamic index meal

Interventions

High glyceamic index meal 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; Pre high-GI; Start high-GI

Low glyceamic index meal 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; Pre low-GI; Start low-GI

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Steno Diabetes Center Copenhagen: lead

Study Sites (1)

Steno Diabetes Center Copenhagen Clinical Translational Research, Diabetes Technology

Herlev, DK-2730, Denmark

Location

MeSH Terms

Conditions

Diabetes Mellitus, Type 1

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases

Study Officials

• Kirsten Nørgaard, Professor

  Steno Diabetes Center Copenhagen Clinical Translational Research, Diabetes Technology

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Karen Rytter, RN, PhD

CONTACT

+45 39680800; karen.rytter@regionh.dk

Ajenthen Ranjan, MD, PhD

CONTACT

+45 39680800; ajenthen.ranjan@regionh.dk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD, DMSc

Model Details: the study contains two sub-studies: breakfast and lunch

Study Record Dates

• First Submitted: May 23, 2025
• First Posted: June 15, 2025
• Study Start: June 30, 2025
• Primary Completion: May 1, 2026
• Study Completion (Estimated): June 1, 2027
• Last Updated: June 15, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

DK (1)