Study of Insulin Treatment Modalities in Adults With Cystic Fibrosis-Related Diabetes After Elexacaftor-Tezacaftor-Ivacaftor Therapy.

BACKGROUND

Several studies have shown improvements in glucose control after initiating elexacaftor/tezacaftor/ivacaftor (ETI) in cystic fibrosis-related diabetes (CFRD) patients. However, ETI's impact on insulin treatment remains unclear. This observational multicenter study aimed to analyze insulin treatment characteristics in adults with preexisting CFRD after ETI treatment initiation.

METHODS

Data on diabetes treatment and continuous glucose monitoring (CGM) were retrospectively collected for 1 year before and up to 2 years after ETI treatment initiation in adults with CFRD from 13 French CF centers. We analyzed the type of insulin treatment, insulin doses, daily distribution, and CGM parameters after 1 year of ETI therapy.

RESULTS

From April to December 2024, 107 individuals were included. The mean age was 33.2 ± 9.3 years, 49% were female, and diabetes treatment was diet for 14%, multiple daily injections for 65%, and pump for 21% of patients. After 1 year of ETI, total and bolus insulin doses decreased significantly from 0.37 IU/kg/day (0.19-0.60) to 0.30 IU/kg/day (0.17-0.49) (P = 0.02) and from 0.27 IU/kg/day (0.14-0.50) to 0.17 IU/kg/day (0.10-0.30), P = 0.0003) respectively. Among patients on a diet, 33.3% started insulin treatment, while 6.5% of patients on insulin treatment discontinued insulin. CGM parameters showed significant decreases in time below the range <70 mg/dL (from 3% [1-8.5] to 2% [0-4], P = 0.001) and coefficient of variation (from 35% [28.7-41.7] to 33.1% [26.8-39.2], P = 0.001).

CONCLUSIONS

These findings indicate a reduction in insulin doses, particularly prandial insulin, as well as decreased glucose variability and hypoglycemia following ETI therapy in CFRD patients. Further long-term studies are needed to confirm these results.