The development of CFTR (cystic fibrosis conductance transmembrane regulator) modulators for people with cystic fibrosis (pwCF) and eligible for these treatments is a true therapeutic revolution. The major beneficial effect of CFTR modulators (CFTRm) on pulmonary function and the reduction of pulmonary exacerbations should have a considerable impact on the quality of life and patient's life expectancy. Data on the impact of CFTRm on glucose tolerance abnormalities are still very fragmentary. The investigators can think that their use, earlier and earlier in the history of the disease, will transform the evolutionary trajectories of patients on the respiratory, nutritional and metabolic levels.

Diabetes represents a major challenge in the management of pwCF because it is a factor in morbidity and mortality at all stages of the disease, from children to patients with terminal respiratory failure requiring lung transplantation. Early abnormalities in glucose tolerance observed in childhood, before the stage of diabetes, are also associated with poor pulmonary and nutritional outcomes. Experimental data suggest a positive effect of CFTRm on insulin secretion. However, investigators do not currently know the impact of CFTRm in patients with very early glucose disorders or at the stage of diabetes treated with insulin. Recently continuous glucose measurement (CGM) devices represent very effective tools for assessing abnormalities in glucose tolerance before the stage of diabetes and for monitoring patients treated with insulin.

Inclusion Criteria:

• Patients with cystic fibrosis aged over 18
• Patients treated for 1 year by elexacaftortezacaftor-ivacaftor
• Normal tolerant or intolerant to glucose or presenting with cystic fibrosis related diabetes treated or not with insulin
• Patient who had a continuous glucose monitoring in the 6 months before and 6 months after one year of treatment with elexacaftor-tezacaftor-ivacaftor

Exclusion Criteria:

• Patient not eligible for triple CFTR modulator
• Patient intolerant to triple corrector
• Pregnant woman

Patients with cystic fibrosis aged over 18, followed in cystic fibrosis ambulatory care services of 18 french centers