Continuous Glucose Monitoring Parameter and Oral Glucose Tolerance Testing (OGTT) Parameters in Children and Young Adults With Cystic Fibrosis (CF)

November 9, 2026 updated by: Northwell Health

As modulator therapies extend the lifespan of CF patients, the detection of complications like Cystic Fibrosis Related Diabetes (CFRD) becomes increasingly vital. The current gold standard for CFRD screening, the 2-hour OGTT, is cumbersome and suffers from low compliance. This study proposes that Continuous Glucose Monitoring (CGM) could offer a more comprehensive, easier, and potentially more compliant screening method. The research aims to correlate various CGM parameters (e.g., time in hyperglycemia) with traditional glycemic markers like OGTT glucose levels, GMI, average glucose, variability, and HbA1c. Additionally, the research seeks to understand patient and parent/guardian preferences for CFRD screening modalities. This prospective observational study will involve CF patients wearing a Dexcom CGM around the time of standard OGTT and HbA1c tests, followed by surveys, with the ultimate goal of paving the way for CGM to improve early detection and management of dysglycemia in CF children.

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.

Detailed Description

As modulator therapy changes the landscape of cystic fibrosis (CF), children with CF will live longer and healthier lives with less pulmonary exacerbations. Still, other complications like Cystic Fibrosis Related Diabetes and underlying dysglycemia may become more apparent as lifespans of CF patients increase. It is therefore essential that clinicians have the tools to understand early stages of dysglycemia to prevent long term complications of CFRD. At present, 2 hours 75-gram OGTT remains the gold standard annual screen for CFRD. This test is both cumbersome for patients and limits a clinician's interpretation of glycemic control to a limited time frame. Although OGTT is currently used to diagnose CFRD, it can be cumbersome for patients and time consuming. OGTT compliance is therefore not surprisingly low in the CF population with about 49 % of CF centers having a more than 50% completion of annual OGTT. Continuous glucose monitoring (CGM), on the other hand, offers the ability to obtain more data on longer time periods in a much easier fashion. Thus, CGMs have the potential to glean a more fine-tuned understanding of a patient's glycemic control. Moreover, CGMs can make glycemic testing easier on patients, thereby increasing compliance of annual glycemic testing. The investigators hypothesize the correlation of CGM parameters of hyperglycemia like % of time > 180 mg/dl, % of time> 150 mg/dL with 1- and 2-hour OGTT glucose levels, Glucose Management Indicator (GMI), average glucose, glucose variability, and HbA1c levels. The investigators also aim to explore patient views and preferences of OGTT and CGM for screening of CFRD through surveys after CGM wear.

The investigators hope to be able to correlate 1- and 2-hour glucose values on OGTT to % in range parameters on a continuous glucose monitor. This will pave the way to better understand glycemic control in children with CF and risk for CFRD with data from a CGM even without an OGTT in the future. The investigators also hope to understand patient and parent/guardian preferences towards CFRD screening modalities.

Study Design: Prospective observational study. Eligible patients will have a CGM placed for up to10-day wear within the 3 months before or after clinically appropriate OGTT and A1c. OGTT testing will include 1- and 2-hour glucose levels and HbA1c as per standard of care. A Dexcom CGM will be placed in clinic onto the subjects upper arm. Survey exploring patient and parent/guardian preference will be provided after the CGM is removed.

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.
30

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 Locations

  • United States
    • New York
      • New York, New York, United States, 11042
        • Recruiting
        • Northwell Health
        • Contact:

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

10 years to 25 years (Child, Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Patients with Cystic Fibrosis
  2. 10-25 years of age who have obtained or will obtain a OGTT within 3 months of recruitment and CGM placement.

Exclusion Criteria:

  1. Diagnosis of diabetes mellitus type 1 or type 2
  2. Use of the following medication: steroid course, Metformin therapy,
  3. Concurrent CV disease or malignancy, kidney failure, lung transplant.
  4. Does not have access to personal Bluetooth device compatible with Dexcom G7 application.

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: Screening
  • Allocation: N/A
  • Interventional Model: Single Group 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: Pediatric Cystic Fibrosis Patients Undergoing Concurrent CGM Monitoring and OGTT Testing

Pediatric Cystic Fibrosis patients (ages 10-25 years) will wear a continuous glucose monitor (Dexcom G7) for up to 10 days within 3 months of an annual Oral Glucose Tolerance Test (OGTT) and complete a survey to evaluate correlations between CGM parameters and OGTT values and assess patient/guardian preferences for CFRD screening methods.
Device: Continuous Glucose Monitor

Continuous glucose monitors, such as Dexcom, have been established as a standard component of clinical care for continuous blood glucose monitoring. These devices are widely utilized in diabetes management clinics and demonstrate a robust safety and efficacy profile. The intervention also includes administration of a patient preference survey as outlined in the study protocol.

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
Average Blood Glucose Level from Continuous Glucose Monitoring
Time Frame: Up to 10 days of CGM wear (within 3 months of the Oral Glucose Tolerance Test).

Mean glucose level recorded over the continuous glucose monitoring (CGM) wear period (mg/dL)
Up to 10 days of CGM wear (within 3 months of the Oral Glucose Tolerance Test).

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
Percentage of Time Glucose Exceeds 150 mg/dL from Continuous Glucose Monitoring
Time Frame: Up to 10 days of CGM wear (within 3 months of the Oral Glucose Tolerance Test).

The proportion of time during the CGM wear period that glucose levels were above 150 mg/dL (%)
Up to 10 days of CGM wear (within 3 months of the Oral Glucose Tolerance Test).
Percentage of Time Glucose Exceeds 180 mg/dL from Continuous Glucose Monitoring
Time Frame: Up to 10 days of CGM wear (within 3 months of the Oral Glucose Tolerance Test).

The proportion of time during the CGM wear period that glucose levels were above 180 mg/dL (%)
Up to 10 days of CGM wear (within 3 months of the Oral Glucose Tolerance Test).
Fasting Plasma Glucose Level from Oral Glucose Tolerance Test
Time Frame: Single measurement at the start of the OGTT (within 3 months of CGM wear).

Plasma glucose level measured after an overnight fast, as part of the Oral Glucose Tolerance Test (OGTT) (mg/dL)
Single measurement at the start of the OGTT (within 3 months of CGM wear).
1 hour Plasma Glucose Level from Oral Glucose Tolerance Test
Time Frame: Single measurement 1 hour after glucose load (within 3 months of CGM wear).

Plasma glucose level measured 1 hour after glucose administration as part of the Oral Glucose Tolerance Test (OGTT) (mg/dL)
Single measurement 1 hour after glucose load (within 3 months of CGM wear).
2-Hour Plasma Glucose Level from Oral Glucose Tolerance Test
Time Frame: Single measurement 2 hours after glucose load (within 3 months of CGM wear).

Plasma glucose level measured 2 hours after glucose load administration during the OGTT (mg/dL)
Single measurement 2 hours after glucose load (within 3 months of CGM wear).
Forced Expiratory Volume in 1 Second (FEV1) as a Percentage of Predicted
Time Frame: Within 3 months of CGM placement (standard of care assessment).

Lung function parameter reflecting the volume of air exhaled in the first second during a forced breath, expressed as a percentage of the predicted value. (%)
Within 3 months of CGM placement (standard of care assessment).
Forced Vital Capacity (FVC) as a Percentage of Predicted
Time Frame: Within 3 months of CGM placement (standard of care assessment).

Lung function parameter reflecting the total volume of air exhaled during a forced breath, expressed as a percentage of the predicted value (%)
Within 3 months of CGM placement (standard of care assessment).
Hemoglobin A1c (HbA1c) Level
Time Frame: At the time of OGTT (within 3 months of CGM wear).

A measure of average blood glucose level (%)
At the time of OGTT (within 3 months of CGM wear).
Body Mass Index (BMI) Z-Score
Time Frame: Within 3 months of CGM placement (standard of care assessment).

Age- and sex-adjusted Body Mass Index standardized score, reflecting nutritional status (z-score)
Within 3 months of CGM placement (standard of care assessment).
Response to Survey Question on CFRD Screening Preferences
Time Frame: After 10 days of CGM wear

Participant's (and/or parent/guardian's) response to the Likert scale questions regarding preferences for Cystic Fibrosis Related Diabetes
After 10 days of CGM wear

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.
Northwell Health

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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.
June 23, 2025

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.
August 1, 2027

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.
August 1, 2027

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).
June 29, 2026

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.
November 9, 2026

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.
November 12, 2026

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.
November 12, 2026

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.
November 9, 2026

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.
October 1, 2026

More Information

Terms related to this study

Keywords

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.
  • 24-0945-CCMC

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

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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