CGM Dynamic Index for Predicting Prediabetes in 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