One-Year Effect of Elexacaftor/Tezacaftor/Ivacaftor Therapy on HbA1c Levels and Insulin Requirement in Patients with Insulin-Dependent Cystic Fibrosis-Related Diabetes: A Retrospective Observational Study

Abstract

Introduction: The impact of ETI therapy on pulmonary function and nutritional status has been widely studied; the literature on the possible outcomes on glycemic control and insulin requirement in patients affected by CFRD is controversial. Aim: The main objective of our study was to evaluate HbA1c levels in patients with cystic fibrosis-related diabetes (CFRD) after one year of therapy with elexacaftor/tezacaftor/ivacaftor (ETI). The secondary objective was to study the changes in the total daily insulin dose (TDD), pulmonary function and metabolism in this population. Materials and methods: A retrospective single-center observational study was conducted at the Regional Cystic Fibrosis Centre and Diabetology Centre of IRCCS Istituto Giannina Gaslini. The observation period was divided into four different time points: initiation (T0), 3 months (T3mo), 6 months (T6mo) and 12 months (T12mo) of ETI therapy. Demographic and clinical data were collected. The results were then stratified by genotype (homozygous or heterozygous F508del). Results: Twenty-eight patients with CFRD undergoing insulin therapy were included. TDD (IU) significantly decreased at T3mo and T6mo, but not at T12mo, whereas HbA1c decreased significantly at all three times. The number of hospitalizations and pulmonary exacerbations decreased significantly. Conclusion: We demonstrated both improvement in glycemic control (by means of HbA1c) and insulin requirement in insulin-dependent CFRD patients after one year of ETI treatment.

Keywords

• CFRD
• cystic fibrosis
• diabetes
• CFTR modulators
• ETI treatment