Effect of 18 months elexacaftor-tezacaftor-ivacaftor on body mass index and glycemic control in adults with cystic fibrosis

BACKGROUND & AIMS:Malnutrition and cystic fibrosis related diabetes (CFRD) are common comorbidities in cystic fibrosis (CF). Cystic fibrosis transmembrane regulator (CFTR) modulators have shown beneficial effects on respiratory status. This study aims to determine the effect of elexacaftor-tezacaftor-ivacaftor (ETI) on body mass index (BMI) and glycemic control. METHODS:A retrospective, observational study of a cohort of 17 adult CF patients was conducted at the CF reference center of Ghent University Hospital. BMI evolution was analyzed 18 months before and 0, 3, 6, 12 and 18 months after the start of ETI. The evolution of insulin dependence and the 2 h oral glucose tolerance test (OGTT) results were described until 36 months after start of ETI, in a small subgroup of ten patients with CFRD or impaired glucose tolerance (IGT). RESULTS:A significant increase in mean BMI of 1.2 kg/m2 (±1.3 SD) was observed. Most weight gain was observed in the first 3 months after starting treatment. This effect was sustained during the observed period of 18 months. Six patients had insulin dependent CFRD, of which three were able to stop insulin after starting ETI. Two patients with CFRD treated with dietary measures showed an initial normalization of the 2 h OGTT, but deterioration at 36 month follow-up. CONCLUSIONS:After initiation of ETI an increase in BMI was observed in adults with CF. ETI can have a beneficial impact on glucose metabolism in patients with CFRD, leading to a possible need for reduction or cessation of insulin therapy.