Alternate Measures of Glucose During OGTT Testing for CFRD

NCT05568134 | Completed DMC

• 1 other identifier: 22-020249
• Study Type: observational
• Target: 14
• Locations: 1 country
• Sites: 1

Brief Summary

Although early detection and treatment of cystic fibrosis-related diabetes (CFRD) can lead to significant clinical improvements and prolong life, rates of screening are poor likely due to the burdensome nature of oral glucose tolerance testing (OGTT). The investigators propose to assess the feasibility and accuracy of two screening tools, continuous glucose monitoring (CGM) and a home OGTT kit (GTT@home). If this pilot study reveals acceptable accuracy of either device, this study will allow for future studies exploring home-based OGTT screening.

Conditions

Cystic Fibrosis; Cystic Fibrosis-related Diabetes

Keywords

continuous glucose monitor; oral glucose tolerance test

Outcome Measures

Primary Outcomes (3)

• Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose

  Differences in fasting glucose will be measured by the difference in mg/dl between plasma glucose, CGM measured glucose, and GTT@home measured glucose.

  Fasting glucose before OGTT

• Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose

  Differences in the 1 hour glucose during the OGTT will be measured by the difference in mg/dl between plasma glucose, CGM measured glucose, and GTT@home measured glucose.

  1 hour mark in OGTT

• Agreement between plasma glucose, CGM measured glucose using the Dexcom G7, and GTT@home glucose

  Differences in the 2 hour glucose during the OGTT will be measured by the difference in mg/dl between plasma glucose, CGM measured glucose, and GTT@home measured glucose.

  2 hour mark in OGTT

Secondary Outcomes (7)

• Agreement between the categorical diagnosis of normal glucose tolerance (NGT), impaired glucose tolerance (IGT), indeterminate glycemia (INDET), and CFRD as defined by plasma glucose, CGM glucose, and GTT@home glucose.

  Up to 2 hours

• Difference between plasma glucose and CGM measured glucose after the fasting glucose

  Up to 20 minutes after the fasting glucose

• Difference between plasma glucose and CGM measured glucose after the 1 hour mark during the OGTT.

  Up to 20 minutes after the 1 hour mark in the OGTT

• Difference between plasma glucose and CGM measured glucose after the 2 hour mark during the OGTT.

  Up to 20 minutes after the 2 hour mark in the OGTT

• The ability of untrained participants to successfully complete the GTT@home kit without any guidance from the research team

  Up to 2 hours

Study Arms (1)

OGTT Cohort

All enrolled participants will complete an OGTT.

Diagnostic Test: Oral glucose tolerance test

Interventions

Oral glucose tolerance test DIAGNOSTIC_TEST

An oral glucose tolerance test will be completed. A fasting glucose will be measured. Participants will drink 1.75 g/kg of dextrose (up to a maximum of 75 grams) within 10 minutes. Glucose values will be measured at 1 hour and 2 hours.

OGTT Cohort

Eligibility Criteria

• Age: 10 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

A total of 15 subjects with cystic fibrosis (CF) over 10 years of age will be approached to participate.

You may qualify if:

• Diagnosis of cystic fibrosis
• ≥ 10 years of age
• Fluency in written and spoken English as the GTT@Home is currently only available in English

You may not qualify if:

• Hospitalization or treatment with IV antibiotics or supraphysiologic glucocorticoids within 4 weeks
• Major medical or psychiatric disorders other than CF
• Use of medications known to impact the accuracy of the Dexcom G7 (hydroxyurea, \>2g acetaminophen per day)
• History of severe adhesive reactions that may lead to an inability to tolerate CGM wear

Sponsors & Collaborators

• Children's Hospital of Philadelphia: lead
• Cystic Fibrosis Foundation: collaborator

Study Sites (1)

Children's Hospital of Philadelphia

Philadelphia, Pennsylvania, 19104, United States

Location

MeSH Terms

Conditions

Cystic Fibrosis

Interventions

Glucose Tolerance Test

Condition Hierarchy (Ancestors)

Pancreatic Diseases; Digestive System Diseases; Lung Diseases; Respiratory Tract Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Infant, Newborn, Diseases

Intervention Hierarchy (Ancestors)

Blood Chemical Analysis; Clinical Chemistry Tests; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Endocrine; Investigative Techniques

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 3, 2022
• First Posted: October 5, 2022
• Study Start: July 17, 2023
• Primary Completion: December 13, 2024
• Study Completion: December 13, 2024
• Last Updated: February 24, 2025

Record last verified: 2025-02

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)