Predicting diabetes in cystic fibrosis using continuous glucose monitoring

CGM Dynamic Index (CDI) for Predicting Prediabetes in People With Cystic Fibrosis

This pilot will test whether a new score from continuous glucose monitors can predict which people with cystic fibrosis and prediabetes will develop diabetes.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 70 (estimated)
• Ages: 12 Years to 55 Years
• Sex: All
• Sponsor: Indiana University (Academic / other)
• Locations: 1 site (Indianapolis, Indiana)
• Trial ID: NCT06642610 on ClinicalTrials.gov

What this trial studies

This pilot enrolls people with cystic fibrosis aged 12–55 who do not have diabetes or who have prediabetes and will collect continuous glucose monitor (CGM) readings to develop a CGM Dynamic Index (CDI) that predicts progression to cystic fibrosis–related diabetes. Participants who already use a personal CGM for cystic fibrosis–related diabetes will be invited to share their device data without requiring OGTT or HbA1c visits. Investigators will combine CGM time-series features with available clinical measures (such as OGTT and HbA1c) to train and validate the predictive model. The study excludes people who are pregnant, have had a transplant, use immunosuppressants or oral steroids, have adhesive allergies, or have severe concurrent conditions that could confound glucose data.

Who should consider this trial

Good fit: Ideal candidates are people with cystic fibrosis aged 12–55 who do not yet have diabetes or who have prediabetes and who can wear a CGM and use a compatible smartphone.

Not a fit: People who are pregnant, post-transplant, taking immunosuppressants or steroids, allergic to adhesives, or with severe concurrent illnesses are unlikely to be eligible and may not benefit from this approach.

Why it matters

Potential benefit: If successful, the CDI could flag people with cystic fibrosis who are likely to develop diabetes earlier, enabling earlier monitoring and treatment to reduce complications.

How similar studies have performed: CGM has been used to characterize glucose patterns in cystic fibrosis, but creating a validated CGM-based index specifically to predict progression to cystic fibrosis–related diabetes is a novel approach with limited prior validation.

Eligibility criteria

Inclusion Criteria:

* CF individuals aged 12-55 years.
* CF without diabetes or with prediabetes (as defined by OGTT and HbA1c).
* Willing to use a continuous glucose monitoring system with compatible smart phone for glucose data collection.

A person with CFRD and already using CGM, we will just collect their personal CGM data, and they are not required to have OGTT or HbA1c visit.

Exclusion Criteria:

* Pregnancy.
* History of transplant.
* Use of immunosuppressant drugs.
* Use of oral steroids or any medication known to interfere with glucose.
* Allergy to adhesives.
* Individuals with severe concurrent medical conditions that could confound glucose monitoring data (e.g., terminal illness, major organ failure).
* Conditions that may make unsafe for participants to do study or impair or confound the study at the discretion of the investigator

Where this trial is running

Indianapolis, Indiana

• Indiana University Health, University Hospital — Indianapolis, Indiana, United States (Recruiting)

Study contacts

• Study coordinator: Eslam Montaser, PhD

Conditions Prediabetes; Cystic Fibrosis; Cystic Fibrosis-related Diabetes