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

Journal of Asthma. 59(1):115-125, 2022 01.

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 6-18 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 (FEV1) was 91.3 +/- 9.2%. EIB
occurred in 54.2% of patients. In CPET, the peak oxygen uptake (VO2peak)
was 34.1 +/- 7.8 mL kg-1 min-1. A significant correlation between
ventilatory reserve and FEV1 (r = 0.57; p = 0.003) was found. Similarly,
there was a significant correlation between CPET and percent of FEV1 fall
in the EIB test for both VE/VO2 (r = 0.47; p = 0.02) and VE/VCO2 (r =
0.46; p = 0.02). Patients with FEV1<80% had lower ventilatory reserve (p =
0.009). In addition, resting heart rate correlated with VO2peak (r=-0.40;
p = 0.04), VE/VO2 (r = 0.46; p = 0.02) and VE/VCO2 (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.