Impact of triple transmembrane regulator therapy on glucose metabolism in cystic fibrosis related diabetes during clinical practice

Abstract

Aims: To evaluate the impact of elexacaftor/tezacaftor/ivacaftor (ETI) therapy on Cystic Fibrosis Related Diabetes (CFRD) glycemic control and insulin treatment in patients with CFRD during clinical practice.

Methods: We carried out a retrospective observational study of 23 adult patients with CFRD who started treatment with ETI. They had, at least, one F508del mutation. Data were collected before ETI initiation and 3, 6, and 12 months after.

Results: Glycemic control measured by HbA1c significantly improved by 0.3 % (0.1-0.5) after 3 months of ETI therapy (p = 0.004) and kept this improvement during follow-up (p < 0.001). The proportion of patients needing multiple daily injections of insulin was reduced by 16 % (p = 0.023). Total daily insulin dose dropped by 0.12 (0.05-0.18) UI/kg/day (p < 0.001). Data derived from Flash Continuous Glucose Monitoring (CGM) for patients treated with insulin stayed unchanged after insulin reduction, except for a significant 8 % (0.3-15.6) increase in the Time In Tight Range (TITR) between 70 and 140 mg/dL (p = 0.043).

Conclusion: ETI therapy impacted CFRD in clinical practice reducing insulin needs and improving glycemic control measured by HbA1c and CGM. The improvements can be observed from the first 3 months of treatment.

Keywords: CFTR modulator; Continuous glucose monitoring; Cystic Fibrosis Related Diabetes; Elexacaftor – tezacaftor – ivacaftor.