Determinants of exercise capacity in children and adolescents with severe therapy-resistant asthma.

Schindel CS; Schiwe D; Heinzmann-Filho JP;Gheller MF; Campos NE; Pitrez PM; Donadio MVF;

The Journal of asthma : official journal of the Association for the Care of Asthma [J Asthma] 2020 Oct 07, pp. 1-13. Date of Electronic Publication: 2020 Oct 07.

Objective: To evaluate the exercise capacity of children and adolescents with severe therapy resistant asthma (STRA) aiming to identify its main determinants.
Methods: Cross-sectional study including individuals aged 6 to 18 years with a diagnosis of STRA. Clinical (age and gender), anthropometric (weight, height and body mass index) and disease control data were collected. Lung function (spirometry), cardiopulmonary exercise testing (CPET) and exercise-induced bronchoconstriction (EIB) test were performed.
Results: Twenty-four patients aged 11.5 ± 2.6 years were included. The mean forced expiratory volume in one second (FEV 1 ) was 91.3 ± 9.2%. EIB occurred in 54.2% of patients. In CPET, the peak oxygen uptake (VO 2 peak) was 34.1 ± 7.8 -1 .min -1 . A significant correlation between ventilatory reserve and FEV 1 (r = 0.57; p  = 0.003) was found. Similarly, there was a significant correlation between CPET and percent of FEV 1 fall in the EIB test for both V E /VO 2 (r = 0.47; p  = 0.02) and V E /VCO 2 (r = 0.46; p  = 0.02). Patients with FEV 1 <80% had lower ventilatory reserve ( p  = 0.009). In addition, resting heart rate correlated with VO 2 peak (r=-0.40; p  = 0.04), V E /VO 2 (r = 0.46; p  = 0.02) and V E /VCO 2 (r = 0.48; p  = 0.01).
Conclusions: Exercise capacity is impaired in approximately 30% of children and adolescents with STRA. The results indicate that different aspects of aerobic fitness are influenced by distinct determinants, including lung function and EIB.