Background:: Studies indicate that different degrees of curvature in adolescent idiopathic scoliosis (AIS) can influence the change of mechanical ventilation during exercise and
decreased exercise capacity. However, data are lacking to quantify the impact of different degrees during cardiopulmonary exercise testing (CPET). The Incremental Shuttle Walk Test (ISWT) is a CPET
widely used in the literature to evaluate children and adolescents. This study aimed to evaluate the distance and physiological responses during ISWT in patients with EIA. Also, they were measured the
respiratory muscle strength, pulmonary function and its correlation with the physiological responses during ISWT.
Methods: This was a cross-sectional study, which were included 46 adolescents with EIA. These were divided into two groups, adolescents angle calculated by the Cobb method, more than
45 ° (EIA> 45 °) less than 45 ° (EIA <45 °). The control group consisted of 20 healthy adolescents. All participants were subjected to ISWT using a gas analyzer, which quantified the physiological
responses such as oxygen consumption (VO2), VO2 corrected for body mass (VO2 / kg), the efficiency of oxygen capitation (OUES), tidal volume (VT), minute ventilation (VE) and ventilatory pattern (ΔVT
/ ΔlnVE). It was also performed pulmonary function test and obtained the value of forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1).
Results: Patients with AIS> 45 ° showed lower values when compared to EIA Group <45 ° and controlling for the following variables: travelled distance (p <0.001), VO2 / kg (p <0.001),
VT (p = 0.001), VE (p = 0.001), OUES intercept (p = 0.043), CVF (p = 0.001) and FEV1 (p = 0.005). In patients with EIA were found moderate correlations between FVC (r = - 0.506), VT (r = - 0.476) with
the angle of thoracic main Cobb; the distance was correlated with VE (r = 0.609) and VO2 / kg (r = 0, 541); as well as the ΔVC / lnVE correlated with VO2 (r = 0.411) and OUES (r = 0.562).
Conclusions: Conclusion: The Incremental Shuttle Walk Test was a test able to identify lower exercise capacity in patients with EIA. Given that, adolescents with
angulation > 45 ° have worse values for the physiological responses during ISWT and walk shorter distances. Furthermore, the higher the spinal curvature, the worse the exercise capacity and lung
function. Therefore, we conclude that the magnitude of spinal curvature exerts influence on the variables studied.