Effect of Postprandial Insulin Administration of Faster-acting Insulin Analogue Versus Pre-prandial Administration of Acting-insulin Analogue in Cystic Fibrosis Related Diabetes

The investigators hypothesis that post prandial administration of Insulin faster-acting aspart insulin in patients with CFRD may contribute to a better metabolic control with a decrease of hypoglycaemia and facilitate insulin administration according to the real food intake. The use of Insulin faster-acting aspart insulin will facilitate the functional insulin therapy. More particularly for CF patients, optimization of metabolic control should contribute to maintain a good nutritional status and to slowing the decline of respiratory function and improve the quality of life. Patients with cystic fibrosis related diabetes and treated by multiple insulin injection (minimal three insulin injection per day or basal bolus insulin regimen) or insulin pump with CGM from over 3 months were included in an open, randomized, two-treatments - 4 periods of 3 months - 2 groups cross-over superiority study. Each group of patients will test both insulin treatments (A = pre prandial Aspart insulin, F = post prandial Faster-acting aspart insulin) in alternating periods with the following sequences: Group 1: A-F-A-F, Group 2: F-A-F-A The patients will be randomized to either one or the other sequence, which defines the groups, and take A or F in each of the 4 periods of the study. Each treatment period will last 3 months. CGM (free style libre, Abott) will be performed for 2 weeks at baseline and after each 4 months period.