The primary objective of this pilot study is to develop a CGM-based model to predict the progression from prediabetes to diabetes in individuals with cystic fibrosis.

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