Extended Bolus for Meals in a Closed-loop System

NCT05454891 | Completed Results DMC FDA Device

• 2 other identifiers: 589925K23DK121942-02
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to evaluate whether the use of an extended bolus will improve glucose control with high-fat high protein meals using a closed-loop system. The new knowledge gained from this study may provide a method to allow for the proper administration of insulin over an extended period to mitigate the risk of prolonged hyperglycemia or early hypoglycemia.

Conditions

Type 1 Diabetes

Outcome Measures

Primary Outcomes (1)

• Glucose Area Under Curve [AUC]

  Area under the curve between glucose trace and starting glucose (mg/dL\* min)

  0 to 5 hours post-meal onset

Secondary Outcomes (11)

• Percentage of Time Between 70-180 mg/dL

  0 to 5 hours post-meal onset

• Percentage of Time in Hypoglycemic Range (Defined as < 70 mg/dL)

  0 to 5 hours post-meal onset

• Average Glucose

  0 to 5 hours post-meal onset

• Percentage of Time in Hyperglycemic Range (Defined as ≥180 mg/dL);

  0 to 5 hours post-meal onset

• Insulin Dosage

  0 to 5 hours post-meal onset

Study Arms (2)

High Fat High Protein (HFHP) Meal- extended then standard insulin bolus arm

EXPERIMENTAL

Subjects will receive extended meal bolus for breakfast on the first day and standard meal bolus on the second day of the study.

Device: Tandem t:slim X2 insulin pump: Extended bolus of insulin then standard bolus of insulin

High Fat High Protein (HFHP) Meal- standard then extended insulin bolus arm

EXPERIMENTAL

Subjects will receive standard meal bolus for breakfast on the first day and extended meal bolus on the second day.

Device: Tandem t:slim X2 insulin pump: Standard bolus of insulin then extended bolus of insulin

Interventions

Tandem t:slim X2 insulin pump: Standard bolus of insulin then extended bolus of insulin DEVICE

For a standardized HFHP breakfast, participants will receive a standard bolus of insulin on the first morning and an extended bolus of insulin on the second morning of the study.

High Fat High Protein (HFHP) Meal- standard then extended insulin bolus arm

Tandem t:slim X2 insulin pump: Extended bolus of insulin then standard bolus of insulin DEVICE

For a standardized HFHP breakfast, participants will receive an extended meal bolus of insulin on the first morning and a standard meal bolus of insulin on the second morning of the study.

High Fat High Protein (HFHP) Meal- extended then standard insulin bolus arm

Eligibility Criteria

• Age: 13 Years - 19 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Age between 13 and 19 years old, A1C \> 6% at screening
• Diagnosed with type 1 diabetes for at least one year
• Total daily dose (TDD) of insulin ≥ 0.3 units/kg/day
• Currently using the Control IQ closed-loop system
• Willing to abide by meal recommendations and study procedures
• Willing and able to sign the Informed Consent Form (ICF) and/or has a parent or guardian willing and able to sign the ICF
• Use an Android or Apple smartphone
• Willingness not to start any new non-insulin glucose-lowering agent during the course of the trial
• Participant and parent(s)/guardian(s) willingness to participate in all training sessions as directed by study staff
• Parent/guardian proficient in reading and writing English
• Live in the United States, with no plans to move outside the United States during the study period

You may not qualify if:

• A1C \>10%
• One or more episodes of severe hypoglycemia or DKA requiring ER visit or hospitalization within the past three months
• Used non-insulin anti-diabetic medication within the last 30 days other than metformin
• Known history of gastroparesis, seizure disorder, adrenal insufficiency, or ongoing renal or hepatic disease
• Pregnancy or lactation
• Untreated or unstable hypothyroidism
• Currently undergoing cancer treatment or systemic treatment with steroids
• Untreated or inadequately treated mental illness
• Current alcohol abuse
• Current illness that would interfere with participation in the study
• Delayed gastric emptying or any concurrent conditions that can be associated with delayed gastric emptying or altered digestion; and the use of any medication that affects gastric emptying
• Celiac Disease

Sponsors & Collaborators

• University of California, San Francisco: lead
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): collaborator

Study Sites (1)

University of California San Francisco

San Francisco, California, 94158, United States

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

Results Point of Contact

• Title: Laya Ekhlaspour, MD
• Organization: UCSF

laya.ekhlaspour@ucsf.edu

415-514-8531

Study Officials

• Laya Ekhlaspour, MD

  University of California, San Francisco

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants will be randomly assigned (1:1) in blocks of two to the order in which they receive the two premeal insulin boluses: extended followed by standard bolus or a standard followed by extended bolus.

Study Record Dates

• First Submitted: June 24, 2022
• First Posted: July 12, 2022
• Study Start: July 15, 2022
• Primary Completion: December 19, 2024
• Study Completion: December 19, 2024
• Last Updated: May 12, 2026
• Results First Posted: May 12, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)