The Impact of a Moderate Carbohydrate Diet in Children With Type 1 Diabetes on Hybrid Closed-loop Therapy (COMBINE1)

August 20, 2024 updated by: Universitaire Ziekenhuizen KU Leuven

The Impact of Carbohydrate Restriction on Glycemic Control in Children and Adolescents With Type 1 Diabetes Using a Hybrid Closed-loop Insulin Delivery System: a Randomized Cross-over Study

In the past, carbohydrate restriction was indicated as a treatment for people with type 1 diabetes when exogenous insulin was not available. Now it is mainly used as an added treatment for people with type 1 diabetes on top of standard insulin administration and glucose monitoring. Despite previous studies, the impact of carbohydrate restriction on glycemic control and quality of life is still not clear. Furthermore, few studies exist on carbohydrate restriction in children with type 1 diabetes and combined with the use of hybrid closed-loop insulin delivery. Therefore this study will determine the impact on glycemic control and the feasability of a moderate carbohydrate diet compared to a traditional diet in children (7-17 years) with type 1 diabetes on top of using a hybrid closed-loop system. In this randomized, crossover study, 28 children will follow a moderate carbohydrate diet (four weeks) and a traditional diet (four weeks) in randomized order. With a run-in period (two weeks) prior to the first diet and a wash-out period (six weeks) between the two diets, the children will participate in the study for a total of 16 weeks. The primary endpoint is the difference of time spent in target range (defined as a sensor glucose value between 70 and 180 mg/dL) between the four-week moderate carbohydrate diet and the four-week traditional diet.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
28

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Signed informed consent (ICF) (both children/adolescents and parents)
  • ≥7 and ≤17 years old at moment of ICF signature
  • ≥6 months type 1 diabetes diagnosis at moment of ICF signature
  • ≥3 months use of the hybrid closed-loop system Medtronic MiniMedTM 780G, Tandem t:slim X2 Control-IQTM or Mylife Ypsopump with CamAPS algorithm at moment of ICF signature
  • Ability to understand, read, write and speak Dutch, French or English at moment of ICF signature

Exclusion Criteria:

  • <7 or >17 years old at moment of ICF signature
  • <6 months type 1 diabetes diagnosis at moment of ICF signature
  • <3 months use of the advanced hybrid closed-loop system Medtronic MiniMedTM 780G, Tandem t:slim X2 Control-IQTM or Mylife Ypsopump with CamAPS algorithm at moment of ICF signature
  • Any other insulin therapy than advanced hybrid closed-loop system Medtronic MiniMedTM 780G , Tandem t:slim X2 Control-IQTM or Mylife Ypsopump with CamAPS algorithm at moment of ICF signature
  • Failure to understand, read, write or speak Dutch, French or English at moment of ICF signature

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Group 1: 1st Traditional diet, 2nd Moderate carbohydrate diet
The group that starts with the traditional diet in the first 4-week diet period. After wash-out, this group will start with the moderate carbohydrate diet in the second 4-week diet period.
Other: Moderate carbohydrate diet
During the moderate carbohydrate diet, participants will be asked to limit his/her carbohydrate intake to no more than 30% of their total energy intake.
Other: Traditional diet
During the traditional diet, participants do not follow any diet, however their carbohydrate intake must be at least 50% of their total energy intake.
Experimental: Group 2: 1st Moderate carbohydrate diet, 2nd Traditional diet
The group that starts with the traditional diet in the first 4-week diet period. After wash-out, this group will start with the moderate carbohydrate diet in the second 4-week diet period.
Other: Moderate carbohydrate diet
During the moderate carbohydrate diet, participants will be asked to limit his/her carbohydrate intake to no more than 30% of their total energy intake.
Other: Traditional diet
During the traditional diet, participants do not follow any diet, however their carbohydrate intake must be at least 50% of their total energy intake.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Time in range
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of time spent in range (70-180 mg/dL) between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Time in tight range
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of time spent in range (70-140 mg/dL) between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Time below range
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of time spent below range (<70 mg/dL) between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Time in level 2 hypoglycemia
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of time spent below range of 54 mg/dL between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Time above range
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of time spent above range (>180 mg/dL) between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Time in level 2 hyperglycemia
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of time spent above range of 250 mg/dL between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Hemoglobin A1c
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of hemoglobin A1c between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Mean blood glucose
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of mean blood glucose between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Glycemic variability: standard deviation and coefficient of variation
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of glycemic variability, in terms of standard deviation (SD) and coefficient of variation (CV) of blood glucose levels between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Daily insulin dose
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference of insulin doses (total, basal and bolus) between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Number of severe hypoglycemic events
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in the frequency of severe hypoglycemic events between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Number of diabetic ketoacidosis
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in the frequence of diabetic ketoacidosis between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Body weight
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in body weight between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Body mass index
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in body mass index between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Blood lipids (total cholesterol, triglycerides, high density lipoprotein and low density lipoprotein concentrations)
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in blood lipids (total cholesterol, triglycerides, high density lipoprotein and low density lipoprotein concentrations) between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Satisfaction with the diet in the context of diabetes treatment
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in the satisfaction with the diet (Diabetes treatment satisfaction questionnaire - DTSQs) between the moderate carbohydrate diet and the traditional diet. The DTSQs has a scale of 0-48 and a higher score is associated with a higher treatment satifaction.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Bioelectrical impedance analysis
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in bioelectrical impedance analysis between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Carb ratio
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in carb ratio between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Active insulin time
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in active insulin time between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Number of people who use glucose target 100 mg/dL, 110 mg/dL and 120 mg/dL
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in umber of people who use glucose target 100 mg/dL, 110 mg/dL and 120 mg/dL between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Consumed carbohydrates
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in consumed carbohydrates between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Meal composition
Time Frame: 4 weeks moderate carbohydrate diet and 4 weeks traditional diet
Difference in meal composition a between the moderate carbohydrate diet and the traditional diet.
4 weeks moderate carbohydrate diet and 4 weeks traditional diet

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Universitaire Ziekenhuizen KU Leuven

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Kristina Casteels, Prof, UZ Leuven

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 15, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 14, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 20, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 22, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 22, 2024

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 20, 2024

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2024

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • S68499

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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