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

Associations Between Sleep Quality and Asthma Control, Pulmonary Inflammation, Asthma Severity, Exercise Capacity, and Quality of Life in Children With Asthma: A Cross-sectional Study

Asthma is a condition characterized by ongoing inflammation of the lower respiratory system, leading to symptoms such as shortness of breath, wheezing, coughing, and chest tightness. Beyond acute symptoms, children with asthma may face ongoing issues, such as decreased physical fitness, sleep disturbances, and a reduced quality of life. This study aimed to explore the connections between sleep quality, asthma control, pulmonary inflammation, exercise capacity, and overall wellbeing in children aged 6 to 12 years. Forty children with varying asthma severity were evaluated for clinical control status, sleep disturbances, quality of life, and exercise ability using various questionnaires and tests. Results showed that 15% had intermittent/mild asthma while 85% had moderate/severe asthma, with 75% experiencing uncontrolled asthma. The analysis indicated a strong correlation between improved asthma control, reduced pulmonary inflammation, better sleep quality, and enhanced quality of life, accounting for 20% of the variations in the children's quality of life scores.

Functional capacity and quality of life in children and adolescents with sickle cell anemia

OBJECTIVE

To evaluate the functional and exercise capacity, lung function, quality of life of children and adolescents with sickle cell anemia (SCA HbSS) and to test the reproducibility of functional capacity tests in this population.

METHOD

Cross-sectional study with volunteers with SCA Hb-SS (SCAG), aged 6-18 years matched in age and gender to the control group (CG) with healthy individuals. Spirometry, 5-repetition sit-to-stand test (5STS-test), modified shuttle test (MST), and Pediatric Quality of Life Questionnaire (PedsQL) were performed. The reproducibility of 5STS-test and MST was evaluated: RESULTS: Forty eight volunteers of SCAG and 48 of CG were evaluated. Lung function of SCAG (FVC: 92 ± 15% pred.; FEV₁ /FVC: 84 ± 8% pred.) was worse than the CG (104 ± 15% pred.; FEV₁ /FVC: 90 ± 6% pred.) p < 0.05. SCAG had worse functional capacity registered by distance walked: 576 m (515-672 m) and 5STS-test: 8 s (7.4-8.9 s) compared with the CG who showed distance walked: 1010 m (887-1219 m) and 5STS-test: 7 s (7.0-8.1 s), p < 0.001. SCAG had worse quality of life compared to CG, p < 0.05. The reproducibility of MST (ICC 0.99 (0.98-0.99 IC-95%)) and 5STS-test (ICC 0.80 (0.69-0.88) was considered good, p < 0.001.

CONCLUSION

Children and adolescents with sickle cell anemia presented worse capacity to walk or run, and to perform sit-to-stand test when compared with their control peers. Additionally, they have poorer quality of life. The MST and 5STS-test showed good reproducibility to be applied in pediatric individuals with SCA.

Heart rate recovery in asthmastic children and adolescents after clinical field test

BACKGROUND

Inflammation caused by chronic lung disease in childhood may lead to delayed heart rate recovery (HRR) however, there is lack of evidence on HRR in this population. The aim was to assess HRR after functional capacity testing in asthmatic children and adolescents and to compare with severity and disease control.

METHOD

This was a study secondary to a randomized control trial. The modified shuttle test (MST) was performed to assess functional capacity and HRR. This is an externally cadenced test in which the distance walked is the outcome. HRR was assessed after MST and was defined as HR at exercise peak minus HR in the second minute after the end of exercise. Asthma control was assessed by the Asthma Control Test (ACT). Data normality was tested by Shapiro Wilk and the comparison between groups was made by Student's t test or Mann Whitney test for numerical variables, and by Chi-square test for categorical variables. Statistical significance was considered when p < 0.05. SPSS version 20 was used in the analyzes.

RESULTS

The sample included 77 patients diagnosed with asthma (asthma group - AG) who were regularly treated for asthma. Control group (CG) consisted of 44 volunteers considered healthy, matched in age and gender to AG. The median age of CG was 12 (10-14) years and in AG 11 (9-13 years) being classified as mild to moderate asthmatic, and 57% of the sample had controlled asthma by ACT. Distance walked in the CG was 952 ± 286 m and AG 799 ± 313 m, p = 0.001. HRR was more efficient in CG (79 ± 15 bpm) compared to AG (69 ± 12 bpm), p = 0.001. The mild (69 ± 12 beats) and severe (72 ± 15 beats) AG presented worse HRR compared to control group (79 ± 15 bpm), p < 0.05.

CONCLUSIONS

Asthmatic children and adolescents have delayed HRR after modified Shuttle test compared to their peers, suggesting that asthma leads to autonomic nervous system imbalance.

TRIAL REGISTRATION

Registered in Clinical Trials under number NCT02383069 and approved by the Universidade Nove de Julho - UNINOVE Research Ethics Committee, protocol number 738192/2014.

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

Introduction

Several tests may be used to assess exercise intolerance in severe therapy-resistant asthma (STRA), including the gold standard cardiopulmonary exercise test (CPET) and the modified shuttle test (MST).

Objective

To correlate the distance achieved in the MST with peak oxygen uptake (VO₂peak) and to compare the maximal heart rate (HRmax) obtained in both tests in children and adolescents with STRA.

Methods

This is a cross-sectional study, with 19 children and adolescents with STRA. Demographic, anthropometric, clinical data, and spirometric values were collected. CPET and the MST were performed in two consecutive visits. HRmax, pulse oxygen saturation, and dyspnea were compared between tests. The distance achieved in the MST was correlated with VO₂peak.

Results

Nineteen patients with a mean age of 11.5 ± 2.5 years were included. The mean HRmax (bpm) achieved was 180.8 ± 12.10 for the MST and 187.6 ± 9.35 for CPET, whereas the mean HRmax as a percentage of predicted (HRmax%) was 90.7 ± 6.5 for the MST and 93.8 ± 4.5 for CPET. A difference of only 6 bpm was found for HRmax (p = 0.10) and of 3% for HRmax% (p = 0.06) between tests. A strong correlation was found between the MST (r = 0.79; p = 0.001) and VO₂peak measured through CPET. However, there were no correlations between the MST and both body mass index (r = -0.14; p = 0.564) and forced expiratory volume in the first second - FEV₁ (r = -0.02; p = 0.917).

Conclusion

The results demonstrate that the MST distance strongly correlates with VO₂peak, measured through CPET, and the main physiological variable responses were similar between both tests. Our results provide additional data for the use of the MST to assess exercise capacity in children and adolescents with STRA.