Effects on growth, weight and body composition after CFTR modulators in children with cystic fibrosis.

Background: Cystic Fibrosis (CF) is associated with compromised nutrition status, which is responsible for morbidity and mortality along with lung function decline. This study was designed to examine changes in anthropometric markers and body composition parameters by bioelectrical impedance analysis after CFTR modulator (CFTRm) treatment.

Methods: We compared anthropometric parameters and body composition before and after 6 and 12 months of CFTRm treatment. Results are stratified into subgroups according to the modulator used with dual therapy with lumacaftor + ivacaftor or tezacaftor + ivacaftor (LUMA/TEZ + IVA) or triple therapy with elexacaftor + tezacaftor + ivacaftor (ELE + TEZ + IVA). Body composition data are available in patients treated with ELE + TEZ + IVA.

Results: Two hundred and thirty-four children (55.1% male) were recruited. The median age was 13.6 years (inter-quartile range [IQR] 10.7-16.1). We can observe a statistically significant increase in the weight Z score and BMI Z score after CFTRm. In terms of changes in body composition, we observe a significant increase in fat mass (FM) expressed both in kilograms and as a percentage at 6 months (p < .05; Wilcoxon-test), with no such differences found at 12 months. We also observe a statistically significant increase in fat-free-mass (FFM), expressed in kilograms at 6 and 12 months (p < .05; Wilcoxon-test).

Conclusion: Weight status improved and changes in body composition occurred in children after CFTRm therapy, including an increase of fat mass. Further studies are needed to confirm these changes in body composition and their impact on disease progression.