Can the Childhood Physical Activity Questionnaire Be Used to Identify Physical Activity Levels in Children With Asthma?

Objective: Children with asthma who are physically active have a better quality of life, emphasizing the importance of activity monitoring and promotion in daily life. The validity of self-reported activity measurements has been questioned in pediatric populations. In this study, we aim to compare the Physical Activity Questionnaire for Children (PAQ-C) with objectively measured PA using accelerometry. Design: In this comparison study, the pooled dataset of two cross-sectional studies was used, which prospectively home-monitored PA using the alternative self-report PAQ-C questionnaire as well as with the criterion standard accelerometry (Actigraph wGT3X-BT and GT1M). Participants:Ninety children with pediatrician-diagnosed asthma participated in the study. Main Outcome Measures:Correlation coefficients were calculated to determine the relation between the PAQ-C and accelerometer data. The predictive value of the PAQ-C in differentiating between achieving and failing the recommended daily level of moderate-to-vigorous activity (MVPA) was evaluated with receiver operator characteristic (ROC) analysis. Results: The results showed weak to moderate correlations of the PAQ-C with the accelerometer data (r = 0.29-0.47). A PAQ-C cutoff of 3.09 showed the best performance on predicting whether the recommended level of MVPA was achieved. With this cutoff, 21 of the 39 children that did achieve their daily MVPA level (53.8% sensitivity) and 33 of the 46 children that did fail their daily MVPA level (71.7% specificity) were correctly classified. A PAQ-C score of 3.5 revealed a negative predictive value of 100% for assessing physical inactivity. Conclusion: This study revealed a weak relation between the PAQ-C and PA assessed with accelerometry. However, a PAQ-C score of 3.5 or higher might be used as a low-cost and easy-to-use PA screening tool for ruling out physical inactivity in a portion of the pediatric asthma population. Clinical Trial Registration: Netherlands Trial Register: Trial NL6087.

Assessing paediatric exercise-induced bronchoconstriction using electromyography.

BACKGROUND: Asthma is one of the most common chronic diseases in childhood, occurring in up to 10% of all children. Exercise-induced bronchoconstriction (EIB) is indicative of uncontrolled asthma and can be assessed using an exercise challenge test (ECT). However, this test requires children to undergo demanding repetitive forced breathing manoeuvres. We aimed to study the electrical activity of the diaphragm using surface electromyography (EMG) as an alternative measure to assess EIB. METHODS: Forty-two children suspected of EIB performed an ECT wearing a portable EMG amplifier. EIB was defined as a fall in FEV 1 of more than 13%. Children performed spirometry before exercise, and at 1, 3 and 6 min after exercise until the nadir FEV1 was attained and after the use of a bronchodilator. EMG measurements were obtained between spirometry measurements. RESULTS: Twenty out of 42 children were diagnosed with EIB. EMG peak amplitudes measured at the diaphragm increased significantly more in children with EIB; 4.85 µV (1.82-7.84), compared to children without EIB; 0.20 µV (-0.10-0.54), (p<0.001) at the lowest FEV 1 post-exercise. Furthermore, the increase in EMG peak amplitude could accurately distinguish between EIB and non-EIB using a cut-off of 1.15 µV (sensitivity 95%, specificity 91%). CONCLUSION: EMG measurements of the diaphragm are strongly related to the FEV1 and can accurately identify EIB. EMG measurements are a less invasive, effort-independent measure to assess EIB and could be an alternative when spirometry is not feasible.

Assessing Exercise-Induced Bronchoconstriction in Children; The Need for Testing.

Objective: Exercise-induced bronchoconstriction (EIB) is a specific morbidity of childhood asthma and a sign of insufficient disease control. EIB is diagnosed and monitored based on lung function changes after a standardized exercise challenge test (ECT). In daily practice however, EIB is often evaluated with self-reported respiratory symptoms and spirometry. We aimed to study the capacity of pediatricians to predict EIB based on information routinely available during an outpatient clinic visit. Methods: A clinical assessment was performed in 20 asthmatic children (mean age 11.6 years) from the outpatient clinic of the MST hospital from May 2015 to July 2015. During this assessment, video images were made. EIB was measured with a standardized ECT performed in cold, dry air. Twenty pediatricians (mean years of experience 14.4 years) each evaluated five children, providing 100 evaluations, and predicted EIB severity based on their medical history, physical examination, and video images. EIB severity was predicted again after additionally providing baseline spirometry results. Results: Nine children showed no EIB, four showed mild EIB, two showed moderate, and five showed severe EIB. Based on clinical information and spirometry results, pediatricians detected EIB with a sensitivity of 84% (95% CI 72-91%) and a specificity of 24% (95% CI 14-39%).The agreement between predicted EIB severity classifications and the validated classifications after the ECT was slight [Kappa = 0.05 (95% CI 0.00-0.17)]. This agreement still remained slight when baseline spirometry results were provided [Kappa = 0.19 (95% CI 0.06-0.32)]. Conclusion: Pediatricians' prediction of EIB occurrence was sensitive, but poorly specific. The prediction of EIB severity was poor. Pediatricians should be aware of this in order to prevent misjudgement of EIB severity and disease control.

BMI predicts exercise induced bronchoconstriction in asthmatic boys.

BACKGROUND: Exercise induced bronchoconstriction (EIB) is a frustrating morbidity of asthma in children. Obesity has been associated with asthma and with more severe EIB in asthmatic children. OBJECTIVES: To quantify the effect of BMI on the risk of the occurrence of EIB in children with asthma. METHODS: Data were collected from six studies in which exercise challenge tests were performed according to international guidelines. We included 212 Children aged 7-18 years, with a pediatrician-diagnosed mild-to-moderate asthma. RESULTS: A total of 103 of 212 children (49%) had a positive exercise challenge (fall of FEV1 ≥ 13%). The severity of EIB, as measured by the maximum fall in FEV1 , was significantly greater in overweight and obese children compared to normal weight children (respectively 23.9% vs 17.9%; P = 0.045). Asthmatic children with a BMI z-score around +1 had a 2.9-fold higher risk of the prevalence of EIB compared to children with a BMI z-score around the mean (OR 2.9; 95%CI: 1.3-6.1; P < 0.01). An increase in BMI z-score of 0.1 in boys led to a 1.4-fold increased risk of EIB (OR 1.4; 95%CI: 1.0-1.9; P = 0.03). A reduction in pre-exercise FEV1 was associated with a higher risk of EIB (last quartile six times higher risk compared to highest quartile (OR 6.1 [95%CI 2.5-14.5]). CONCLUSIONS: The severity of EIB is significantly greater in children with overweight and obesity compared to non-overweight asthmatic children. Furthermore, this study shows that the BMI-z-score, even with a normal weight, is strongly associated with the incidence of EIB in asthmatic boys.

Can a single dose response predict the effect of montelukast on exercise-induced bronchoconstriction?

RATIONALE: Exercise-induced bronchoconstriction (EIB) can be prevented by a single dose of montelukast (MLK). The effect is variable, similar to the variable responsiveness observed after daily treatment with MLK. We hypothesized that the effect of a single MLK-dose (5 or 10 mg) on EIB could predict the clinical effectiveness of longer term once daily treatment. METHODS: This was a prospective, open-label study. Twenty-four asthmatic adolescents (12-17 years) suboptimally controlled by low-dose inhaled corticosteroids, with ≥10% post-exercise fall in FEV1 , were included. They performed an exercise test at baseline, 20 hr after a single MLK-dose and 40-44 hr after the last dose of 4 weeks once daily treatment. The correlations between the effect of a single dose and 4 weeks treatment on area under the curve (AUC) and maximum % fall in FEV1 were calculated. RESULTS: AUC0-20 min decreased significantly after a single MLK-dose (P = 0.001, CI: 64.9-218.2), but not after 4 weeks of treatment (P = 0.080, CI: -12.2 to 200.4). There was a moderate correlation between the effect of a single MLK-dose and 4 weeks treatment on AUC0-20 min , r = 0.49 (P = 0.011), and maximum % fall in FEV1 , r = 0.40 (P = 0.035). CONCLUSION: The protection provided by a single MLK-dose against EIB only modestly predicts the effect of regular treatment against EIB in adolescent asthmatics on low-dose inhaled corticosteroids. If used on a daily base, MLK offered clinically significant protection against EIB in two thirds of adolescents suboptimally controlled by low-dose ICS.

Assessment of exercise-induced bronchoconstriction in adolescents and young children.

Recent research shows important differences in exercise-induced bronchoconstriction (EIB) between children and adults, suggesting a different pathophysiology of EIB in children. Although exercise can trigger classic symptoms of asthma, in children symptoms can be subtle and nonspecific; parents, children, and clinicians often do not recognize EIB. With an age-adjusted protocol, an exercise challenge test can be performed in children as young as 3 years of age. However, an alternative challenge test is sometimes necessary to assess potential for EIB in children. This review summarizes age-related features of EIB and recommendations for assessing EIB in young children and adolescents.

The effect of nebulized salbutamol or isotonic saline on exercise-induced bronchoconstriction in elite skaters following a 1,500-meter race: study protocol for a randomized controlled trial.

BACKGROUND: Prevalence of exercise-induced bronchoconstriction (EIB) is high in elite athletes, especially after many years training in cold and dry air conditions. The primary treatment of EIB is inhaling a short-acting beta-2-agonist such as salbutamol. However, professional speed skaters also inhale nebulized isotonic saline or tap water before and after a race or intense training. The use of nebulized isotonic saline or tap water to prevent EIB has not been studied before, raising questions about safety and efficacy. The aim of this study is to analyze the acute effect of nebulized isotonic saline or salbutamol on EIB in elite speed skaters following a 1,500-meter race. METHODS: This randomized controlled trial compares single dose treatment of 1 mg nebulized salbutamol in 4 mL of isotonic saline, or with 5 mL of isotonic saline. A minimum of 13 participants will be allocated in each treatment group. Participants should be between 18 and 35 years of age and able to skate 1,500 m in less than 2 min 10 s (women) or 2 min 05 s (men). Repeated measurements of spirometry, forced oscillation technique, and electromyography will be performed before and after an official 1,500-m race. Primary outcome of the study is the difference in fall in FEV1 after exercise in the different treatment groups. The trial is currently enrolling participants. DISCUSSION: Elite athletes run the risk of pulmonary inflammation and remodeling as a consequence of their frequent exercise, and thus increased ventilation in cold and dry environments. Although inhalation of nebulized isotonic saline is commonplace, no study has ever investigated the safety or efficacy of this treatment. TRIAL REGISTRATION: This trial protocol was registered with the Dutch trial registration for clinical trials under number NTR3550.

Where to from here for exercise-induced bronchoconstriction: the unanswered questions.

The role of epithelial injury is an unanswered question in those with established asthma and in elite athletes who develop features of asthma and exercise-induced bronchorestriction (EIB) after years of training. The movement of water in response to changes in osmolarity is likely to be an important signal to the epithelium that may be central to the onset of EIB. It is generally accepted that the mast cell and its mediators play a major role in EIB and the presence of eosinophils is likely to enhance EIB severity.

Effect of an intranasal corticosteroid on exercise induced bronchoconstriction in asthmatic children.

RATIONALE: Allergic rhinitis and exercise induced bronchoconstriction (EIB) are common in asthmatic children. The aim of this study was to investigate whether treatment of allergic rhinitis with an intranasal corticosteroid protects against EIB in asthmatic children. METHODS: This was a double-blind, randomized, placebo-controlled, parallel group study. Subjects aged 12-17 years, with mild-to-moderate asthma, intermittent allergic rhinitis and ≥ 10% fall in FEV(1) at a screening exercise challenge were randomized to 22 ± 3 days treatment with intranasal fluticasone furoate or placebo. The primary outcome was change in exercise induced fall in FEV(1) . Secondary outcomes were changes in the area under the curve (AUC), asthma control questionnaire (ACQ), pediatric asthma quality of life questionnaire (PAQLQ), and exhaled nitric oxide (FeNO). RESULTS: Twenty-five children completed the study. Mean exercise induced fall in FEV(1) (± SD) decreased significantly (95% CI: 0.7-18.2%, P = 0.04) in the fluticasone furoate group from 28.4 ± 15.8% to 19.0 ± 13.8%, compared to the placebo group (27.4 ± 16.0% to 27.4 ± 19.2%). The change in AUC was not significantly different between treatment groups. However, within the fluticasone furoate group the AUC decreased significantly (P = 0.01). Although total PAQLQ score did not improve, the activity limitation domain score improved significantly within the fluticasone furoate group (P = 0.03). No significant changes were observed in FeNO and ACQ. CONCLUSION: Treatment of allergic rhinitis in asthmatic children with an intranasal corticosteroid reduces EIB and tends to improve quality of life.

The effect of stepping down combination therapy on airway hyperresponsiveness to mannitol.

RATIONALE: Controversy exists about the safety of long acting beta2-agonist (LABA) treatment, in particular in children. Combination therapy with a LABA and an inhaled corticosteroid (ICS) is prescribed to children with moderate asthma and can be stepped down by withdrawal of the LABA when asthma is well controlled. OBJECTIVE: To analyze the effect of stepping down from LABA/ICS combination therapy to monotherapy with the same dose of ICS on the airway response to mannitol in asthmatic children. METHODS: 17 children, aged 12-17 years, with clinically stable asthma, receiving combination therapy, were analyzed in this observational prospective open-label study. Children performed a mannitol challenge at baseline and 30±4 days after their medication was stepped down to ICS monotherapy. The changes in the provoking dose of mannitol to cause a 15% fall in FEV(1) (PD(15)), response-dose ratio and recovery time following a short acting beta2-agonist to ≥95% of baseline FEV(1) were assessed. RESULTS: Mannitol PD(15) and response-dose ratio did not significantly change after stepping down. The recovery time following a short acting beta2-agonist to ≥95% of baseline FEV(1) was significantly shorter (p=0.01) after the withdrawal of the LABA. CONCLUSIONS: In short-term follow-up, stepping down clinically stable asthmatic children from combination therapy to monotherapy with an ICS does not change airway hyperresponsiveness (AHR) to mannitol but does shorten recovery time to baseline lung function following a rescue short acting beta2-agonist.

Monitoring pulmonary function during exercise in children with asthma.

OBJECTIVE: Exercise-induced bronchoconstriction (EIB) is defined as acute, reversible bronchoconstriction induced by physical exercise. It is widely believed that EIB occurs after exercise. However, in children with asthma the time to maximal bronchoconstriction after exercise is short, suggesting that the onset of EIB in such children occurs during exercise. AIM: In this study the authors investigate pulmonary function during exercise in cold air in children with asthma. METHODS: 33 Children with asthma with a mean age of 12.3 years and a clinical history of exercise induced symptoms, underwent a prolonged, submaximal, exercise test of 12 min duration at approximately 80% of the predicted maximum heart rate. Pulmonary function was measured before and each minute during exercise. If EIB occurred (fall in forced expiratory volume in 1 s >15% from baseline), exercise was terminated and salbutamol was administered. RESULTS: 19 Children showed EIB. In 12 of these children bronchoconstriction occurred during exercise (breakthrough EIB), while seven children showed bronchoconstriction immediately after exercise (non-breakthrough EIB). Breakthrough EIB occurred between 6 and 10 min of exercise (mean 7.75 min). CONCLUSION: In the majority of children with EIB in this study (ie, 12 out of 19), bronchoconstriction started during, and not after, a submaximal exercise test.

Mannitol and exercise challenge tests in asthmatic children.

BACKGROUND: Bronchial hyperresponsiveness (BHR), a characteristic feature of asthma, can be assessed through standardized bronchial provocation tests (BPT). Exercise as a BPT is used in diagnosing and monitoring exercise induced bronchoconstriction (EIB). Recently a novel osmotic BPT has been developed, using dry powder mannitol. The aim of this study was to investigate the clinical utility of the mannitol challenge to identify asthmatic children with EIB. MATERIALS AND METHODS: Thirty-three clinically stable children, aged 9-18 years, with a history of EIB, performed both mannitol and exercise provocation challenges. Data were composed of a cross tabulation comparing the reaction on exercise provocation challenge to mannitol challenge. Correlations between post-exercise fall in FEV1 and response-dose ratio (RDR) and PD1) of mannitol were calculated. RESULTS: Twenty-five children completed both tests. Pearson's correlation between log-transformed RDR for mannitol and post-exercise fall in FEV1 was r(p) = 0.666 (P < 0.001). There was no significant relationship between the log PD1) of mannitol and post-exercise fall in FEV1. Children on long acting bronchodilator agents (LABA) were significantly (P < 0.05) more likely to have a positive response on the mannitol challenge. Positive and negative predictive values of the mannitol challenge for EIB were 69% and 91%. CONCLUSION: Mannitol challenge appears to be a suitable alternative for an exercise provocation test to assess EIB in asthmatic children. Given the negative predictive value of 91%, it is especially useful to exclude EIB.