Physical fitness and habitual physical activity in children with cystic fibrosis - do they improve with elexacaftor/tezacaftor/ivacaftor therapy?

ABSTRACT

Objectives: The aim of this ongoing longitudinal study is to examine the effects of elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) on aspects of physical fitness (PF, strength endurance, explosive power, coordination under time pressure, coordination for the precision aspect, trunk flexibility, peak workload, habitual physical activity (HPA, steps/day, intensity), and zscores of FEV1 and BMI in children with cystic fibrosis (CF)). All children have been receiving ELX/TEZ/IVA for 19.2 ± 10.4 (11–33) months. Methods: Six children with CF agreed to participate (3f/3 m) mean age 13 ± 4yrs (9–17 yrs), FEV1 z-score − 1.017 ± 1.817 (-3.2–0.8). PFwas assessed using 5 test items at baseline and 4.51 ± 0.98 years later;strength endurance (PU push-ups, SU sit-ups), explosive power (SLJ standing long jump), coordination under time pressure (JSS jumping side to side), coordination for the precision aspect (BB balancing backward on beams), and trunk flexibility (FB, forward bend). Cycle-ergometry (Godfrey-protocol) was used to determine Wpeak. Lung function was measured by spirometry. Results: Significant improvements were seen in test items representing strength endurance (PU, SU) and coordination under time pressure (JSS) (p < .05). Although HPA expressed as steps/day remained the same, thetime of moderate to vigorous intensity of HPA decreases significantly (p < .05). A slight, not significant, improvement of BMI Z-score was observed (p > .05). No or small changes could be observed for the parameter FEV1 z-score, Wpeak, PF, SLJ, BB and FB (p > 0.05). Conclusion: ELX/TEZ/IVA therapy seems to be a facilitator to increase some aspects of PF. The decrease in intensity of HPA is possibly an effect of the COVID-19 Pandemic that has already been described in healthy and asthmatic children. In this ongoing study, we assume that clearer effects will be shown with a greater number of children included. However, ELX/ TEZ/IVA enhanced muscle strength endurance in children with CF.