Validation of the Modified Shuttle Test to Predict Peak Oxygen Uptake in Youth Asthma Patients Under Regular Treatment

Abstract

Background: Oxygen uptake (VO2) evaluations by cardiopulmonary exercise test is expensive and time-consuming. Estimating VO2 based on a field test would be an alternative.Objective: To develop and validate an equation to predict VO2peak based on the modified shuttle test (MST).Methods: Cross sectional study, with 97 children and adolescents with asthma. Participants were divided in two groups: the equation group (EG), to construct the equation model of VO2peak, and the cross-validation group (VG). Each subject performed the MST twice using a portable gas analyzer. The peak VO2peak during MST was used in the equation model. The patients’ height, weight, gender, and distance walked (DW) during MST were tested as independent variables.Results: The final model [-0.457 + (gender × 0.139) + (weight × 0.025) + (DW × 0.002)] explained 87% of VO2peak variation. The VO2peak predicted was similar to VO2peak measured by gas analyzer (1.9 ± 0.5 L/min and 2.0 ± 0.5 L/min, respectively) (p = 0.67), and presented significant ICC 0.91 (IC95% 0.77 to 0.96); p < 0.001. The Bland–Altman analysis showed low bias (-0.15 L/min) and limits of agreement (-0.65 to 0.35 L/min). There was no difference in DW between EG (760 ± 209 m) and VG (731 ± 180 m), p = 0.51.Conclusion: The developed equation adequately predicts VO2peak in pediatric patients with asthma.

Modified Shuttle Test Distance Correlates With Peak Oxygen Uptake in Children and Adolescents With Severe Therapy-Resistant Asthma

“…However, this method requires costly equipment, specialized training, and is not always available in clinical practice (Society, 2003), especially in developing countries. Thus, it is often necessary to determine exercise capacity using field tests and the MST is considered a simple, externally paced, and incremental (progressive increase of velocity) test (Lanza et al, 2018). Several studies (Costa et al, 2018; Labadessa et al, 2018; Lanza et al, 2018; Vendrusculo et al, 2019) have demonstrated good correlations between the distance achieved in the MST and the VO 2 obtained during CPET, both in respiratory diseases and in other clinical conditions.…”

“…Thus, it is often necessary to determine exercise capacity using field tests and the MST is considered a simple, externally paced, and incremental (progressive increase of velocity) test (Lanza et al, 2018). Several studies (Costa et al, 2018; Labadessa et al, 2018; Lanza et al, 2018; Vendrusculo et al, 2019) have demonstrated good correlations between the distance achieved in the MST and the VO 2 obtained during CPET, both in respiratory diseases and in other clinical conditions. Recently, one study (Lanza et al, 2018) showed a strong correlation between the MST and VO 2 (87% prediction power) in children and adolescents with mild/moderate asthma.…”

“…The MST is an externally paced test with 15 levels and presenting the distance reached in a course of 10 m as its main outcome. Considering that an incremental protocol with increasing speed is used, MST mimics frequently used CPET protocols, leading subjects to levels close to exhaustion (Lanza et al, 2018).…”

“…Although several studies (Bradley et al, 1999; Vallier et al, 2016; Lanza et al, 2018; Majd et al, 2019) have shown a good association between maximal oxygen consumption (VO 2 peak) measured during CPET and the distance covered in the MST in adults, little is known for pediatric populations. Evidence suggests differences in both exercise capacity parameters and clinical characteristics of asthma between children and adults (Jenkins et al, 2003; Vinet et al, 2003).…”

“…Evidence suggests differences in both exercise capacity parameters and clinical characteristics of asthma between children and adults (Jenkins et al, 2003; Vinet et al, 2003). To date, only one recent study (Lanza et al, 2018) has evaluated the correlation between these variables in a pediatric sample including mild and moderate asthmatics. Moreover, another study with adult severe asthmatics (Labadessa et al, 2018) showed an important MST reliability.…”