P045 Physical fitness of paediatric cystic fibrosis patients in the era of CFTR modulators

Objectives: Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulators have substantially improved the clinical outcome of CF patients. The aim this study was to investigate physical fitness a pediatric cohort and effects CFTR on exercise test performance. Methods: In retrospective observational single center we reviewed total 137 incremental tests (cycle ergometer) in 64 patients (25 females, 39 males, mean age 15.3 ± 2.4 years) between 2010 2022. Changes pulmonary function (FEV1), peak oxygen uptake (VO2peak) maximal workload (watt) over time as well under influence CFTR-targeted therapies were analyzed. Results: observed significant decline VO2peak from early adolescence until adulthood (p < 0.01), but FEV1 remained stable. 22/64 (34%) had at least one while modulator therapy, 10/22 an prior after 6 months modulators. lumacaftor-ivacaftor or tezacaftor-ivacaftor therapy (6/10), course did not differ compared matched controls seemed flatten. All elexacaftor-tezacaftor-ivacaftor (4/10) showed marked increase FEV1, slightly 3/4 Conclusions: While capacity declined during adolescence, seem more favorable course.