Effects of exercise training and montelukast in children with mild asthma

Anti-muscarinic drugs as preventive treatment of exercise-induced bronchoconstriction (EIB) in children and adults

Regular physical activity is strongly recommended to prevent chronic respiratory diseases, including asthma. On the other hand, vigorous physical training may trigger airway symptoms and bronchoconstriction. The transient airway narrowing occurring because of exercise is named exercise-induced bronchoconstriction (EIB). Despite management according to guidelines, a significant proportion of patients experiences uncontrolled EIB, which thus represents a relevant unmet medical need. In particular, although prevention and treatment of EIB are effectively based on the use of beta-2 bronchodilator drugs, high heterogeneity in individual responses has been reported. Furthermore, even though beta-2 adrenergic drugs remain the mainstay of EIB management, occurrence of tolerance and side effects, as well as doping concerns have been reported with their use. In regard to this, inhaled antimuscarinics could represent an alternative or additional effective and safe bronchodilator therapeutic option for achieving optimal EIB control and minimize adverse events. The present systematic review aims to collect and provide the most updated and evidence-based literature findings on the efficacy and safety of short- and long-acting inhaled anti-muscarinic drugs for the preventive treatment of EIB in both children and adults. Take-Home Message: Anti-muscarinic drugs are effective and safe in preventing EIB, despite response variability is reported. Further studies should focus on long-acting molecules, chronic administration and phenotype-driven effects.

Asthma, exercise and metabolic dysregulation in paediatrics

Asthma is the most frequent chronic disease in childhood. Chest tightness, cough, wheezing and dyspnoea during or after exercise may be unique manifestations of asthma in up to 90% of subjects. Physical activity may be reduced by uncontrolled asthma symptoms and parental beliefs, impairing physical fitness of asthmatic children. Clinicians working in the field of allergy are aware of evidence supporting the benefits of physical activity for patients with asthma. Treatment of asthma is required in order to obtain its control and to avoid any limitation in sports and active play participation. As exercise performance in children with controlled asthma is not different from that of healthy controls, any exercise limitation cannot be accepted. Overweight and obesity may interfere with asthma and exercise, leading to dyspnoea symptoms. Evidences on the effect of insulin resistance on airway smooth muscle and on bronchial hyperactivity are presented. CONCLUSION: Exercise is part of the strategy to obtain the best control of asthma in childhood, but we have to optimise the asthma control therapy before starting exercise programming. Furthermore, it is crucial to give best attention on the effects of obesity and insulin resistance, because they could in turn influence patients' symptoms.

Physical activity for children with chronic disease; a narrative review and practical applications

BACKGROUND

Physical activity (PA) is associated with a diverse range of health benefits. International guidelines suggest that children should be participating in a minimum of 60 min of moderate to vigorous intensity PA per day to achieve these benefits. However, current guidelines are intended for healthy children, and thus may not be applicable to children with a chronic disease. Specifically, the dose of PA and disease specific exercise considerations are not included in these guidelines, leaving such children with few, if any, evidence-based informed suggestions pertaining to PA. Thus, the purpose of this narrative review was to consider current literature in the area of exercise as medicine and provide practical applications for exercise in five prevalent pediatric chronic diseases: respiratory, congenital heart, metabolic, systemic inflammatory/autoimmune, and cancer.

METHODS

For each disease, we present the pathophysiology of exercise intolerance, summarize the pediatric exercise intervention research, and provide PA suggestions.

RESULTS

Overall, exercise intolerance is prevalent in pediatric chronic disease. PA is important and safe for most children with a chronic disease, however exercise prescription should involve the entire health care team to create an individualized program.

CONCLUSIONS

Future research, including a systematic review to create evidence-based guidelines, is needed to better understand the safety and efficacy of exercise among children with chronic disease.

Exercise training as an adjunctive therapy to montelukast in children with mild asthma: A randomized controlled trial

BACKGROUND

This study investigated the effectiveness and safety of exercise training (ET) as an adjunctive therapy to montelukast for children with mild asthma (MA).

METHODS

A total of 72 children, ages 4 to 12 years with MA were randomly assigned to a treatment group or a control group at a ratio of 1:1. The subjects in the treatment group received ET plus montelukast, while the participants in the control group received montelukast alone. The primary endpoint was lung function, as measured by forced expiratory volume in 1 second (FEV1) and ratio between FEV1 and forced vital capacity (FEV1/FVC). The secondary endpoints included the symptom improvements, as measured by clinical assessment score, and quality of life (QoL), as assessed with Paediatric Allergic Disease Quality of Life Questionnaire (PADQLQ) scores. In addition, adverse events were also assessed during the period of this study. All outcomes were measured at baseline, at the end of 6-week treatment and 2-week follow-up after the treatment.

RESULTS

After 6-week treatment and 2-week follow-up, although ET plus montelukast did not show better effectiveness in improving lung function, as evaluated by the FEV1 (P > .05) and FEV1/FVC (P > .05) than montelukast alone, significant relief in clinical symptoms (P < .01), and improvement in QoL (P < .01) have achieved. Additionally, both groups had similar safety profile.

CONCLUSION

The results of this study showed that ET as an adjunctive therapy to montelukast may benefit for children with MA. Further studies are still needed to warrant the results of this study.

Views on Exercise

INTRODUCTION

There is a large prevalence of asthma, particularly among Hispanic children. Although physical activity is a good way to manage asthma, more Hispanic children with asthma lack activity than their healthy classmates. Given this, the purpose of this study was to explore the development of exercise perceptions in Hispanic children with asthma and to further develop an existing explanatory theory.

METHOD

Grounded theory was the approach for the study. Grounded theory illuminated components of exercise perceptions from participants. Participants included Hispanic children with asthma, their families, and professionals who work with Hispanic children with asthma ( n = 29).

RESULTS

Findings from this study supported the previously identified grounded theory called The Process of Creating Perceptions of Exercise. In addition, two new concepts ( cultural and peer influences) were identified that further explain the category of exercise influences.

CONCLUSION

The revised theory can be used to assist in developing nursing interventions aimed at increasing exercise participation among Hispanic children with asthma.

Physical activity, black carbon exposure and airway inflammation in an urban adolescent cohort

OBJECTIVE

Regular physical activity can improve cardiopulmonary health; however, increased respiratory rates and tidal volumes during activity may increase the effective internal dose of air pollution exposure. Our objective was to investigate the impact of black carbon (BC) measured by personal sampler on the relationship between physical activity and fractional exhaled nitric oxide (FeNO), a marker of airway inflammation. We hypothesized that higher personal BC would attenuate the protective effect of physical activity on airway inflammation.

METHODS

We performed a cross-sectional study nested in a birth cohort of African American and Dominican children living in the Bronx and Northern Manhattan, New York City. Children were recruited based on age (target 9-14 year olds) and presence (n=70) or absence (n=59) of current asthma. Children wore wrist mounted accelerometers for 6 days and were classified as 'active' if they had ≥60min of moderate-to-vigorous activity (MVA) each day and 'non-active' if they had <60min of MVA on any given day, based on CDC guidelines. Personal BC measured using a MicroAeth, was assessed during two 24-h periods, at the beginning and end of physical activity assessment. High BC was defined as the upper tertile of BC measured with personal sampler. FeNO measurements were sampled at the beginning and end of the of physical activity assessment.

RESULTS

In multivariable linear regression models, 'active' children had 25% higher personal BC concentrations (p=0.02) and 20% lower FeNO (p=0.04) compared to 'non-active' children. Among children with high personal BC (n=33), there was no relationship between activity and FeNO (p=1.00). The significant protective relationship between activity and airway inflammation was largely driven by children with lower personal BC (n=96, p=0.04).

CONCLUSIONS

Children that live in an urban environment and are physically active on a daily basis have higher personal exposure to BC. High BC offsets the protective relationship between physical activity and airway inflammation.

The analysis of volatile organic compounds in exhaled breath and biomarkers in exhaled breath condensate in children - clinical tools or scientific toys?

Current monitoring strategies for respiratory diseases are mainly based on clinical features, lung function and imaging. As airway inflammation is the hallmark of many respiratory diseases in childhood, noninvasive methods to assess the presence and severity of airway inflammation might be helpful in both diagnosing and monitoring paediatric respiratory diseases. At present, the measurement of fractional exhaled nitric oxide is the only noninvasive method available to assess eosinophilic airway inflammation in clinical practice. We aimed to evaluate whether the analysis of volatile organic compounds (VOCs) in exhaled breath (EB) and biomarkers in exhaled breath condensate (EBC) is helpful in diagnosing and monitoring respiratory diseases in children. An extensive literature search was conducted in Medline, Embase and PubMed on the analysis and applications of VOCs in EB and EBC in children. We retrieved 1165 papers, of which nine contained original data on VOCs in EB and 84 on biomarkers in EBC. These were included in this review. We give an overview of the clinical applications in childhood and summarize the methodological issues. Several VOCs in EB and biomarkers in EBC have the potential to distinguish patients from healthy controls and to monitor treatment responses. Lack of standardization of collection methods and analysis techniques hampers the introduction in clinical practice. The measurement of metabolomic profiles may have important advantages over detecting single markers. There is a lack of longitudinal studies and external validation to reveal whether EB and EBC analysis have added value in the diagnostic process and follow-up of children with respiratory diseases. In conclusion, the use of VOCs in EB and biomarkers in EBC as markers of inflammatory airway diseases in children is still a research tool and not validated for clinical use.

The effects of exercise training in a weight loss lifestyle intervention on asthma control, quality of life and psychosocial symptoms in adult obese asthmatics: protocol of a randomized controlled trial

BACKGROUND

Asthma and obesity are public health problems with increasing prevalence worldwide. Clinical and epidemiologic studies have demonstrated that obese asthmatics have worse clinical control and health related quality of life (HRQL) despite an optimized medical treatment. Bariatric surgery is successful to weight-loss and improves asthma control; however, the benefits of nonsurgical interventions remain unknown.

METHODS/DESIGN

This is a randomized controlled trial with 2-arms parallel. Fifty-five moderate or severe asthmatics with grade II obesity (BMI ≥ 35 kg/m(2)) under optimized medication will be randomly assigned into either weight-loss program + sham (WL + S group) or weight-loss program + exercise (WL + E group). The weight loss program will be the same for both groups including nutrition and psychological therapies (every 15 days, total of 6 sessions, 60 min each). Exercise program will include aerobic and resistance muscle training while sham treatment will include a breathing and stretching program (both programs twice a week, 3 months, 60 min each session). The primary outcome variable will be asthma clinical control. Secondary outcomes include HRQL, levels of depression and anxiety, lung function, daily life physical activity, body composition, maximal aerobic capacity, strength muscle and sleep disorders. Potential mechanism (changes in lung mechanical and airway/systemic inflammation) will also be examined to explain the benefits in both groups.

DISCUSSION

This study will bring a significant contribution to the literature evaluating the effects of exercise conditioning in a weight loss intervention in obese asthmatics as well as will evaluate possible involved mechanisms.

TRIAL REGISTRATION

NCT02188940.

Active Video Game Exercise Training Improves the Clinical Control of Asthma in Children: Randomized Controlled Trial

OBJECTIVE

The aim of the present study was to determine whether aerobic exercise involving an active video game system improved asthma control, airway inflammation and exercise capacity in children with moderate to severe asthma.

DESIGN

A randomized, controlled, single-blinded clinical trial was carried out. Thirty-six children with moderate to severe asthma were randomly allocated to either a video game group (VGG; N = 20) or a treadmill group (TG; n = 16). Both groups completed an eight-week supervised program with two weekly 40-minute sessions. Pre-training and post-training evaluations involved the Asthma Control Questionnaire, exhaled nitric oxide levels (FeNO), maximum exercise testing (Bruce protocol) and lung function.

RESULTS

No differences between the VGG and TG were found at the baseline. Improvements occurred in both groups with regard to asthma control and exercise capacity. Moreover, a significant reduction in FeNO was found in the VGG (p < 0.05). Although the mean energy expenditure at rest and during exercise training was similar for both groups, the maximum energy expenditure was higher in the VGG.

CONCLUSION

The present findings strongly suggest that aerobic training promoted by an active video game had a positive impact on children with asthma in terms of clinical control, improvement in their exercise capacity and a reduction in pulmonary inflammation.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01438294.

Effect of Submaximal Warm-up Exercise on Exercise-induced Asthma in African School Children

BACKGROUND

Regular physical activity has long been regarded as an important component of a healthy lifestyle. Exercise-induced asthma (EIA) is one of the major problems interfering with the performance of exercise. A warm-up exercise programme has been cited as a non-pharmacologic means of reducing EIA, but its effect has not been fully elucidated.

OBJECTIVE

The aims of this study were to determine the prevalence of unrecognized EIA in Pretoria primary school children, determine the effect of a warm-up exercise programme on EIA and to establish the relationship between history of allergy, family history of asthma and EIA.

METHODS

A random sample of 640 school children was selected. The study was divided into three phases. In phase one, a descriptive cross-sectional study was done using the standardized European Community Respiratory Health Survey (ECRHS) questionnaire. In phase two, non-asthmatic participants that returned a completed questionnaire were included in the field study. Pre-test and post-test experimental designs were used, where peak expiratory flow rate (PEFR) was measured at baseline and within ten minutes after exercise. A total of 340 subjects completed the Free Running Asthma Screening Test (FRAST); EIA was defined as a decrease in baseline PEFR ≥ 10% after exercise and 75 children (22%) had EIA. In phase three, 29 of the 75 subjects participated in the warm-up programme which was performed in the laboratory and subjects acted as their own controls. Predefined protocols for the study were followed.

RESULTS

Seventy-five (22%) of the 340 participants had EIA. The mean age, height and weight were 10.51 years, 139.26 cm and 33.45 kg, respectively. Exercise-induced asthma symptoms were cough (25%), chest pain (16%), wheeze (12%) and chest tightness (12%). The history of allergy was 75%, family history of allergy 40% and positive history of allergy when near animals, feathers or in dusty areas 38%. Wheezing during or after exercise, wheezing when near animals, feathers or in dusty areas and chest pain was significant (p < 0.05). The mean PEFR after exercise without warm-up was 4.43 L/min. The mean PEFR after exercise (warm-up) was 4.98. The mean percentage change in PEFR between exercise without warm-up and exercise with warm-up was 14.83%. The paired t-test showed a significant difference between PEFR with warm-up and PEFR without warm-up (p < 0.05).

CONCLUSION

There was a high prevalence of EIA among study participants. Exercise-induced asthma symptoms were significant for wheezing and chest pain. Exercise after warm-up was significant in reducing EIA. This study reports the effect of warm-up exercise on EIA and highlights the need to screen school children for EIA.

Effects of exercise training on airway hyperreactivity in asthma: a systematic review and meta-analysis

BACKGROUND

Although physical exercise is recommended for asthmatics, evidence on the effects of exercise on clinical key factors is still missing.

OBJECTIVES

We performed a systematic review and meta-analysis to determine the effect of exercise training (EXT) on quality of life (QoL), bronchial hyperresponsiveness (BHR), exercise-induced bronchoconstriction (EIB), lung function and exercise capacity, plus the factors affecting changes in QoL and exercise capacity in asthmatics after a period of EXT.

DATA SOURCES

A computerized search was conducted in MEDLINE, EMBASE, and CINAHL (last search on 15 November 2012), without language restriction, and references of original studies and reviews were searched for further relevant studies.

STUDY SELECTION

Two independent investigators screened full-text studies with asthmatic subjects undertaking EXT (defined as training for ≥7 days, ≥2 times per week, ≥5 training sessions in total) that assessed at least one of the following outcomes: QoL, airway hyperreactivity, forced expiratory volume in one second (FEV₁), peak expiratory flow (PEF), inflammatory parameters, exercise capacity, or exercise endurance. Potentially relevant studies were excluded if only respiratory muscle training, breathing exercises or yoga was performed, if asthmatic subjects with co-morbidities were investigated, if only data of mixed patient groups without separate results for asthmatics were presented, if training regimens were not sufficiently specified, if no numerical outcome data were presented, and if new long-term medication was introduced in addition to physical training. Of 500 potentially relevant articles, 13.4 % (67 studies including 2,059 subjects) met the eligibility criteria and were included for further analyses.

STUDY APPRAISAL AND SYNTHESIS METHODS

Data extraction and risk of bias assessment was performed according to the Cochrane Handbook for Systematic Reviews of Interventions. A meta-analysis of all randomized controlled trials (RCTs) was performed to determine the effect of EXT on asthma symptoms, BHR, EIB, FEV₁, exercise capacity and exercise endurance compared with control training. In addition, relative pre/post changes were analysed in all RCTs and controlled trials. Finally, multiple linear regression models were used to identify effects of relative changes in airway hyperreactivity (BHR or EIB), lung function (FEV₁ or PEF) and training hours on QoL and exercise performance.

RESULTS

In a total of 17 studies including 599 subjects, meta-analyses showed a significant improvement in days without asthma symptoms, FEV1 and exercise capacity while BHR only tended to improve. The analysis of relative within-group changes after EXT showed, however, significant improvements in QoL (17 %), BHR (53 %), EIB (9 %), and FEV1 (3 %) compared with control conditions. Multiple linear regression models revealed that changes in airway hyperreactivity and lung function significantly contributed to the change in QoL, while mainly the changes in airway hyperreactivity contributed to the change in exercise capacity.

CONCLUSION

EXT was shown to improve asthma symptoms, QoL, exercise capacity, BHR, EIB, and FEV1 in asthmatics and improvements in BHR explained part of the improvement in QoL and exercise capacity. Thus, physical activity should be recommended as a supplementary therapy to medication. However, more well controlled studies should be performed assessing the relationship of physical activity, QoL, airway hyperreactivity, lung function and especially airway inflammation as well as medication intake.

Ventilation and respiratory mechanics

During dynamic exercise, the healthy pulmonary system faces several major challenges, including decreases in mixed venous oxygen content and increases in mixed venous carbon dioxide. As such, the ventilatory demand is increased, while the rising cardiac output means that blood will have considerably less time in the pulmonary capillaries to accomplish gas exchange. Blood gas homeostasis must be accomplished by precise regulation of alveolar ventilation via medullary neural networks and sensory reflex mechanisms. It is equally important that cardiovascular and pulmonary system responses to exercise be precisely matched to the increase in metabolic requirements, and that the substantial gas transport needs of both respiratory and locomotor muscles be considered. Our article addresses each of these topics with emphasis on the healthy, young adult exercising in normoxia. We review recent evidence concerning how exercise hyperpnea influences sympathetic vasoconstrictor outflow and the effect this might have on the ability to perform muscular work. We also review sex-based differences in lung mechanics.

Evidence-based risk assessment and recommendations for physical activity clearance: respiratory disease

The 2 most common respiratory diseases are chronic obstructive pulmonary disease (COPD) and asthma. Growing evidence supports the benefits of exercise for all patients with these diseases. Due to the etiology of COPD and the pathophysiology of asthma, there may be some additional risks of exercise for these patients, and hence accurate risk assessment and clearance is needed before patients start exercising. The purpose of this review was to evaluate the available literature regarding the risks of exercise for patients with respiratory disease and provide evidence-based recommendations to guide the screening process. A systematic review of 4 databases was performed. The literature was searched to identify adverse events specific to exercise. For COPD, 102 randomized controlled trials that involved an exercise intervention were included (n = 6938). No study directly assessed the risk of exercise, and only 15 commented on exercise-related adverse events. For asthma, 30 studies of mixed methodologies were included (n = 1278). One study directly assessed the risk of exercise, and 15 commented on exercise-related adverse events. No exercise-related fatalities were reported. The majority of adverse events in COPD patients were musculoskeletal or cardiovascular in nature. In asthma patients, exercise-induced bronchoconstriction and (or) asthma symptoms were the primary adverse events. There is no direct evidence regarding the risk of exercise for patients with COPD or asthma. However, based on the available literature, it would appear that with adequate screening and optimal medical therapy, the risk of exercise for these respiratory patients is low.

Antileukotriene reverts the early effects of inflammatory response of distal parenchyma in experimental chronic allergic inflammation

Aims. Compare the effects of montelukast or dexamethasone in distal lung parenchyma and airway walls of guinea pigs (GP) with chronic allergic inflammation. Methods. GP have inhaled ovalbumin (OVA group-2x/week/4weeks). After the 4th inhalation, GP were treated with montelukast or dexamethasone. After 72 hours of the 7th inhalation, GP were anesthetised, and lungs were removed and submitted to histopathological evaluation. Results. Montelukast and dexamethasone treatments reduced the number of eosinophils in airway wall and distal lung parenchyma compared to OVA group (P < 0.05). On distal parenchyma, both treatments were effective in reducing RANTES, NF-κB, and fibronectin positive cells compared to OVA group (P < 0.001). Montelukast was more effective in reducing eotaxin positive cells on distal parenchyma compared to dexamethasone treatment (P < 0.001), while there was a more expressive reduction of IGF-I positive cells in OVA-D group (P < 0.001). On airway walls, montelukast and dexamethasone were effective in reducing IGF-I, RANTES, and fibronectin positive cells compared to OVA group (P < 0.05). Dexamethasone was more effective in reducing the number of eotaxin and NF-κB positive cells than Montelukast (P < 0.05). Conclusions. In this animal model, both treatments were effective in modulating allergic inflammation and remodeling distal lung parenchyma and airway wall, contributing to a better control of the inflammatory response.

Role of leukotrienes in exercise-induced bronchoconstriction before and after a pilot rehabilitation training program

BACKGROUND

Whatever the initial stimulus for the exercise-induced bronchoconstriction (EIB) observed in asthmatic patients after exercise, the final effect is release of bronchoactive mediators, especially cysteinyl leukotrienes. Exercise rehabilitation training programs have been reported to protect against EIB. The exact mechanism(s) involved are not well understood. However, this protective effect may be related to adaptation and better coordination during exercise, depletion of cysteinyl leukotrienes, and/or a sluggish cysteinyl leukotriene response to exercise. The aim of the present work was to test the hypothesis that improvement in the incidence and severity of post-exercise bronchoconstriction after a rehabilitation training program is related to a change in leukotriene levels in response to exercise.

METHODS

Twenty asthmatic children aged 6-12 years and known to develop EIB were enrolled in an exercise training program for 12 weeks. The severity and incidence of EIB before and after training was assessed. Baseline and post-exercise sputum cysteinyl leukotriene levels were assessed before and after the training program.

RESULTS

The training program offered significant protection against EIB with a concomitant decrease in sputum cysteinyl leukotriene levels in response to exercise.

CONCLUSION

A training program can result in depletion and/or a sluggish cysteinyl leukotriene response to exercise and may be responsible for the protective effect of training programs on EIB. It is recommended to use an exercise rehabilitation training program as a complementary tool in the management of bronchial asthma, especially EIB.

Effect of physical training on airway inflammation in bronchial asthma: a systematic review

Background

The majority of the global population cannot afford existing asthma pharmacotherapy. Physical training as an airway anti-inflammatory therapy for asthma could potentially be a non-invasive, easily available, affordable, and healthy treatment modality. However, effects of physical training on airway inflammation in asthma are currently inconclusive. The main objective of this review is to summarize the effects of physical training on airway inflammation in asthmatics.

Methods

A peer reviewed search was applied to Medline, Embase, Web of Science, Cochrane, and DARE databases. We included all observational epidemiological research studies and RCTs. Studies evaluating at least one marker of airway inflammation in asthmatics after a period of physical training were selected. Data extraction was performed in a blinded fashion. We decided a priori to avoid pooling of the data in anticipation of heterogeneity of the studies, specifically heterogeneity of airway inflammatory markers studied as outcome measures.

Results

From the initial 2635 studies; 23 studies (16 RCTs and 7 prospective cohort studies) were included. Study sizes were generally small (median sample size = 30). There was a reduction in C-reactive protein, malondialdehyde, nitric oxide, sputum cell counts and IgE in asthmatics with physical training. Mixed results were observed after training for fractional excretion of nitric oxide and bronchial hyperresponsiveness. The data was not pooled owing to significant heterogeneity between studies, and a funnel plot tests for publication bias were not performed because there were less than 10 studies for almost all outcome measures. Physical training intervention type, duration, intensity, frequency, primary outcome measures, methods of assessing outcome measures, and study designs were heterogeneous.

Conclusion

Due to reporting issues, lack of information and heterogeneity there was no definite conclusion; however, some findings suggest physical training may reduce airway inflammation in asthmatics.

Swimming training for asthma in children and adolescents aged 18 years and under

BACKGROUND

Asthma is the most common chronic medical condition in children and a common reason for hospitalisation. Observational studies have suggested that swimming, in particular, is an ideal form of physical activity to improve fitness and decrease the burden of disease in asthma.

OBJECTIVES

To determine the effectiveness and safety of swimming training as an intervention for asthma in children and adolescents aged 18 years and under.

SEARCH METHODS

We searched the Cochrane Airways Group's Specialised Register of trials (CENTRAL), MEDLINE , EMBASE, CINAHL, in November 2011, and repeated the search of CENTRAL in July 2012. We also handsearched ongoing Clinical Trials Registers.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs of children and adolescents comparing swimming training with usual care, a non-physical activity, or physical activity other than swimming.

DATA COLLECTION AND ANALYSIS

We used standard methods specified in the Cochrane Handbook for Systematic reviews of Interventions. Two review authors used a standard template to independently assess trials for inclusion and extract data on study characteristics, risk of bias elements and outcomes. We contacted trial authors to request data if not published fully. When required, we calculated correlation coefficients from studies with full outcome data to impute standard deviation of changes from baseline.

MAIN RESULTS

Eight studies involving 262 participants were included in the review. Participants had stable asthma, with severity ranging from mild to severe. All studies were randomised trials, three studies had high withdrawal rates. Participants were between five to 18 years of age, and in seven studies swimming training varied from 30 to 90 minutes, two to three times a week, over six to 12 weeks. The programme in one study gave 30 minutes training six times per week. The comparison was usual care in seven studies and golf in one study. Chlorination status of swimming pool was unknown for four studies. Two studies used non-chlorinated pools, one study used an indoor chlorinated pool and one study used a chlorinated but well-ventilated pool.No statistically significant effects were seen in studies comparing swimming training with usual care or another physical activity for the primary outcomes; quality of life, asthma control, asthma exacerbations or use of corticosteroids for asthma. Swimming training had a clinically meaningful effect on exercise capacity compared with usual care, measured as maximal oxygen consumption during a maximum effort exercise test (VO2 max) (two studies, n = 32), with a mean increase of 9.67 mL/kg/min; 95% confidence interval (CI) 5.84 to 13.51. A difference of equivalent magnitude was found when other measures of exercise capacity were also pooled (four studies, n = 74), giving a standardised mean difference (SMD) 1.34; 95% CI 0.82 to 1.86. Swimming training was associated with small increases in resting lung function parameters of varying statistical significance; mean difference (MD) for FEV1 % predicted 8.07; 95% CI 3.59 to 12.54. In sensitivity analyses, by risk of attrition bias or use of imputed standard deviations, there were no important changes on effect sizes. Unknown chlorination status of pools limited subgroup analyses.Based on limited data, there were no adverse effects on asthma control or occurrence of exacerbations.

AUTHORS' CONCLUSIONS

This review indicates that swimming training is well-tolerated in children and adolescents with stable asthma, and increases lung function (moderate strength evidence) and cardio-pulmonary fitness (high strength evidence). There was no evidence that swimming training caused adverse effects on asthma control in young people 18 years and under with stable asthma of any severity. However whether swimming is better than other forms of physical activity cannot be determined from this review. Further adequately powered trials with longer follow-up periods are needed to better assess the long-term benefits of swimming.

Effect of physical training on airway inflammation in animal models of asthma: a systematic review

BACKGROUND

There is little data on the effect of exercise on markers of airway inflammation in human asthmatics. The main objective of this review is to determine the effects of physical training on markers of airway inflammation in animal models of asthma.

METHODS

A peer reviewed search was applied to Medline, Embase, Web of Science, Cochrane, and DARE databases. Data extraction was performed in a blinded fashion.

RESULTS

From the initial 2336 studies, a total of 10 studies were selected for the final analysis. All were randomized controlled trials with low to moderate intensity training on ovalbumin-sensitized mice. In the exercised group of mice, there was a reduction in BAL eosinophils and Th-2 cytokines, no change in Th-1 cytokines, an increase in IL-10, and a reversal of airway remodeling. The data was not pooled owing to significant heterogeneity between studies, and a funnel plot test for publication bias was not performed because there were few studies reporting on any one outcome measure. The asthma models differed between studies in age and gender of mice, as well as in timing of physical training after sensitization. The risk of bias was unclear for some studies though this may not influence outcome measures. The accuracy of data extracted from graphics is unknown.

CONCLUSIONS

Physical training improves airway inflammation in animal asthma models.

Effects of corticosteroid, montelukast and iNOS inhibition on distal lung with chronic inflammation

We evaluated the effects of anti-iNOS (1400W - W) associated with leukotriene antagonist (montelukast - M) or corticosteroid (dexamethasone - D) on distal lung of guinea pigs (GP) with chronic pulmonary inflammation.

METHODS

GP were inhaled with ovalbumin (OVA-2×/week/4 weeks), treated with M (OVAM), D (OVAD) and/or W (OVAW, OVADW, OVAMW) and distal lungs were evaluated by morphometry.

RESULTS

Isolated treatments were not sufficient to reduce all parameters. In OVADW, all parameters were reduced with greater reduction in elastic fibers, TIMP-1, IL-4, IL-5, IFN-gamma and PGF2-alpha compared with OVAD (p<0.05). OVAMW potentiated the reduction of actin, elastic fibers, TIMP-1, IL-4, IL-5, TGF-beta, IFN-gamma, iNOS, and PGF2-alpha to a greater extent than OVAM (p<0.05). A reduction of TIMP-1, IL-4, IL-5, TGF-beta, IFN-gamma and iNOS was observed in OVADW compared with OVAMW (p<0.05).

CONCLUSIONS

Although anti-iNOS paired with montelukast or dexamethasone yields better results than isolated treatments, the most effective pairing for controlling inflammation, oxidative stress and remodeling in this asthma model was found to be corticosteroids and anti-iNOS.

Effects of exercise training on airway closure in asthmatics

We previously reported that responsiveness to methacholine (Mch) in the absence of deep inspiration (DI) decreased in healthy subjects after a short course of exercise training. We assessed whether a similar beneficial effect of exercise on airway responsiveness could occur in asthmatics. Nine patients (male/female: 3/6; mean age ± SD: 24 ± 2 yr) with mild untreated asthma [forced expiratory volume in 1 s (FEV(1)): 100 ± 7.4% pred; FEV(1)/vital capacity (VC): 90 ± 6.5%] underwent a series of single-dose Mch bronchoprovocations in the absence of DI in the course of a 10-wk training rowing program (6 h/wk of submaximal and maximal exercise), at baseline (week 0), and at week 5 and 10. The single-dose Mch was established as the dose able to induce ≥ 15% reduction in inspiratory vital capacity (IVC) and was administered to each subject at every challenge occasion. Five asthmatics (male/female: 1/4; mean age ± SD: 26 ± 3 yr) with similar baseline lung function (FEV(1): 102 ± 7.0% predicted; FEV(1)/VC: 83 ± 6.0%; P = 0.57 and P = 0.06, respectively) not participating in the exercise training program served as controls. In the trained group, the Mch-induced reduction in IVC from baseline was 22 ± 10% at week 0, 13 ± 11% at week 5 (P = 0.03), and 11 ± 8% at week 10 (P = 0.028). The Mch-induced reduction in FEV(1) did not change with exercise (P = 0.69). The reduction in responsiveness induced by exercise was of the same magnitude of that previously obtained in healthy subjects (50% with respect to pretraining). Conversely, Mch-induced reduction in IVC in controls remained unchanged after 10 wk (%reduction IVC at baseline: 21 ± 20%; after 10 wk: 29 ± 14%; P = 0.28). This study indicates that a short course of physical training is capable of reducing airway responsiveness in mild asthmatics.

High-intensity training improves airway responsiveness in inactive nonasthmatic children: evidence from a randomized controlled trial

PURPOSE

the relationship between physical activity and airway health in children is not well understood. The purpose of this study was to determine whether 8 wk of high-intensity exercise training would improve airway responsiveness in prepubescent, nonasthmatic, inactive children.

METHODS

16 healthy, prepubescent children were randomized [training group (TrG) n = 8, control group (ConG) n = 8]. Prior to and following 8 wk of training (or no training), children completed pulmonary function tests (PFTs): forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), forced expiratory flow at 25-75% of vital capacity (FEF(25-75)), and exhaled nitric oxide (FENO). Children completed an incremental cycle Vo(2max) test, eucapnic voluntary hyperventilation (EVH), anthropometric tests, and blood tests to determine fasting blood glucose, total cholesterol, HDL, LDL, and triglycerides. Body fat percentage was determined using dual-energy X-ray absorptiometry pretraining and bioelectrical impedance pre- and posttraining.

RESULTS

there were no differences (P > 0.05) in anthropometric measures or PFTs between TrG and ConG at baseline. In the TrG, there was a significant increase in Vo(2max) (∼24%) and a decrease in total cholesterol (∼13%) and LDL cholesterol (∼35%) following training. There were improvements (P < 0.05) in ΔFEV(1) both postexercise (pre: -7.60 ± 2.10%, post: -1.10 ± 1.80%) and post-EVH (pre: -6.71 ± 2.21%, post: -1.41 ± 1.58%) with training. The ΔFEF(25-75) pre-post exercise also improved with training (pre: -16.10 ± 2.10%, post: -6.80 ± 1.80%; P < 0.05). Lower baseline body fat percentages were associated with greater improvements in pre-post exercise ΔFEV(1) following training (r = -0.80, P < 0.05).

CONCLUSION

these results suggest that in nonasthmatic prepubescent children, inactivity negatively impacts airway responsiveness, which can be improved with high-intensity training. Excess adiposity, however, may constrain these improvements.

Home-based educational interventions for children with asthma

BACKGROUND

While guidelines recommend that children with asthma should receive asthma education, it is not known if education delivered in the home is superior to usual care or the same education delivered elsewhere. The home setting allows educators to reach populations (such as the economically disadvantaged) that may experience barriers to care (such as lack of transportation) within a familiar environment.

OBJECTIVES

To perform a systematic review on educational interventions for asthma delivered in the home to children, caregivers or both, and to determine the effects of such interventions on asthma-related health outcomes. We also planned to make the education interventions accessible to readers by summarising the content and components.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register of trials, which includes the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, AMED and PsycINFO, and handsearched respiratory journals and meeting abstracts. We also searched the Education Resources Information Center database (ERIC), reference lists of trials and review articles (last search January 2011).

SELECTION CRITERIA

We included randomised controlled trials of asthma education delivered in the home to children, their caregivers or both. In the first comparison, eligible control groups were provided usual care or the same education delivered outside of the home. For the second comparison, control groups received a less intensive educational intervention delivered in the home.

DATA COLLECTION AND ANALYSIS

Two authors independently selected the trials, assessed trial quality and extracted the data. We contacted study authors for additional information. We pooled dichotomous data with fixed-effect odds ratio and continuous data with mean difference (MD) using a fixed-effect where possible.

MAIN RESULTS

A total of 12 studies involving 2342 children were included. Eleven out of 12 trials were conducted in North America, within urban or suburban settings involving vulnerable populations. The studies were overall of good methodological quality. They differed markedly in terms of age, severity of asthma, context and content of the educational intervention leading to substantial clinical heterogeneity. Due to this clinical heterogeneity, we did not pool results for our primary outcome, the number of patients with exacerbations requiring emergency department (ED) visit. The mean number of exacerbations requiring ED visits per person at six months was not significantly different between the home-based intervention and control groups (N = 2 studies; MD 0.04; 95% confidence interval (CI) -0.20 to 0.27). Only one trial contributed to our other primary outcome, exacerbations requiring a course of oral corticosteroids. Hospital admissions also demonstrated wide variation between trials with significant changes in some trials in both directions. Quality of life improved in both education and control groups over time.A table summarising some of the key components of the education programmes is included in the review.

AUTHORS' CONCLUSIONS

We found inconsistent evidence for home-based asthma educational interventions compared to standard care, education delivered outside of the home or a less intensive educational intervention delivered at home. Although education remains a key component of managing asthma in children, advocated in numerous guidelines, this review does not contribute further information on the fundamental content and optimum setting for such educational interventions.

Physical activity and the achievement gap among urban minority youth

OBJECTIVES

To outline the prevalence and disparities of physical activity among school-aged urban minority youth, causal pathways through which low levels of physical activity and fitness adversely affects academic achievement, and proven or promising approaches for schools to increase physical activity and physical fitness among youth.

METHODS

Literature review.

RESULTS

A large proportion of youth is insufficiently physically active. Estimates of population-wide levels of physical activity indicate that Black and Hispanic youth are less physically active than White youth, with disparities particularly evident for females. The population segments of youth with lowest levels of physical activity and fitness also have least access to school-based physical activity opportunities and resources. Physical activity affects metabolism and all major body systems, exerting powerful positive influences on the brain and spinal cord and, consequently, on emotional stability, physical health, and motivation and ability to learn. The cornerstone of school-based physical activity programs should be a high-quality physical education program based on national standards. Such programs are strongly recommended by the Task Force on Community Preventive Services as a way to increase physical activity and physical fitness among youth.

CONCLUSIONS

Physical inactivity is highly and disproportionately prevalent among school-aged urban minority youth, has a negative impact on academic achievement through its effects on cognition, and effective practices are available for schools to address this problem. Increasing students' physical activity and physical fitness can best be achieved through a comprehensive approach that includes physical education, wise use of recess and after-school times, co-curricular physical activity opportunities, and bicycling or walking to and from school.

Exercise-Induced Lung Disease: Too Much of a Good Thing?

Exercise in children has important health benefits. However, in elite endurance athletes, there is an increased prevalence of exercise-induced bronchoconstriction and airway inflammation. Particularly at risk are those who practice in cold weather, ice rinks, swimming pools, and air pollution. The inflammation is caused by repetitive episodes of hyperventilation of cold, dry air, allergens, or toxins such as chlorine or air pollution. Children may be particularly at risk for lung injury under these conditions because of the immaturity and ongoing development of their lung. However, studies in pediatric athletes and exercising young children are sparse. Epithelial injury associated with hyperventilation of cold, dry air has not been described in children. However, exercise in the presence of air pollution and chlorine is associated with airway injury and the development of asthma in children; the effect appears to be modulated by both atopy and genetic polymorphisms. While management of exercise-induced bronchoconstriction and asthma is well established, there is little data to guide treatment or prevention of remodeling in athletes or inhalational lung injury in children. Studies underscore the need to maintain high levels of air quality. More investigations should be undertaken to better define the natural history, pathophysiology, and treatment of exercise-induced pulmonary inflammation in both elite athletes and exercising children.

A rat model of exercise-induced asthma: a nonspecific response to a specific immunogen

Exercise-induced bronchoconstriction (EIB) is common; however, key aspects of its pathogenesis are still unclear. We investigated the feasibility of adapting an established animal model of asthma to investigate the earliest stages of EIB. The hypothesis was that a single exposure to a normally innocuous, and brief, exercise challenge could trigger EIB symptoms in rats previously sensitized to ovalbumin (OVA) but otherwise unchallenged. Brown-Norway rats were sensitized by intraperitoneal injection of OVA at 0 and 2 wk. At week 3, animals were exposed to either aerosolized OVA (SS) or exercise (EXS). A trained, blinded, clinical observer graded EIB by respiratory sounds. Plasma and lung cytokine levels were analyzed. No control rats with or without exercise (EX, CON) showed evidence of EIB. Eighty percent of the SS group demonstrated abnormal breath sounds upon exposure to aerosolized OVA. Approximately 30% of EXS rats sensitized to OVA but exposed only to exercise had abnormal breath sounds. Lung tissue levels of TNF-α, IL-1α, growth-related oncogene/keratinocyte/chemoattractant, and IFN-γ were significantly higher (P < 0.001) in the SS group, relative to all other groups. Changes in most of these cytokines were not notable in the EXS rats, suggesting a different mechanism of EIB. Remarkably, IFN-γ, but not the other cytokines measured, was significantly elevated following brief exercise in both sensitized and unsensitized rats. Exercise led to detectable breathing sound abnormalities in sensitized rats, but less severe than those observed following classical OVA challenge. Precisely how this immune crossover occurs is not known, but this model may be useful in elucidating essential mechanisms of EIB.

Physical Activity in Childhood Asthma: Friend or Foe?

Physical activity has been considered as a double-edged sword for children with asthma. Children with asthma are recommended to participate in physical activities like their healthy nonasthmatic peers because regular physical activity positively affects psychological functioning, quality of life, morbidity, and aerobic fitness in children with asthma. However, uncontrolled asthma with ongoing exercise-induced bronchoconstriction may limit participation in sports, free play, and daily living. Observations also suggest that high-intensity exercise performed in cold air, seasonal allergens, pollutants, or respiratory virus infections may increase the risk for asthma in the highly active child. In contrast, a sedentary lifestyle has been highlighted as the explanation for the increased prevalence of asthma in the past decades. However, there is no consensus on whether a low level of physical activity increases the severity or risk of asthma. Use of asthma medications and good asthma control can make the conditions favorable for a physically active lifestyle and influence physical activity level and the level of aerobic fitness.

Exercise-induced asthma in children

Exercise-induced bronchoconstriction affects 40-90% of people with asthma, compared with 3-15% of the general population. Exercise-induced asthma (EIA) is diagnosed on the basis of subjective symptoms of airflow obstruction during and after exercise, objective measures of airflow obstruction and the exclusion of alternative diagnoses. Although the pathogenesis of EIA has not been fully elucidated, two major theories have been proposed: the airway rewarming theory and the hyperosmolarity theory. Increasing evidence suggests that airway inflammation plays a major role in the pathogenesis of EIA. In this article, we review the prevalence, pathogenesis, methods for diagnosis and treatment of EIA, as well as the responsiveness of children and adolescents to EIA therapies.

Effects of exercise training on airway responsiveness and airway cells in healthy subjects

Airway responsiveness to methacholine (Mch) in the absence of deep inspirations (DIs) is lower in athletes compared with sedentary individuals. In this prospective study, we tested the hypothesis that a training exercise program reduces the bronchoconstrictive effect of Mch. Ten healthy sedentary subjects (M/F: 3/7; mean + or - SD age: 22 + or - 3 yr) entered a 10-wk indoor rowing exercise program on rowing ergometer and underwent Mch bronchoprovocation in the absence of DIs at baseline, at weeks 5 and 10, as well as 4-6 wk after the training program was completed. Exercise-induced changes on airway cells and markers of airway inflammation were also assessed by sputum induction and venous blood samples. Mean power output during the 1,000 m test was 169 + or - 49 W/stroke at baseline, 174 + or - 49 W/stroke at 5 wk, and 200 + or - 60 W/stroke at 10 wk of training (P < 0.05). The median Mch dose used at baseline was 50 mg/ml (range 25-75 mg/ml) and remained constant per study design. At the pretraining evaluation, the percent reduction in the primary outcome, the inspiratory vital capacity (IVC) after inhalation of Mch in the absence of DIs was 31 +/- 13%; at week 5, the Mch-induced reduction in IVC was 22 + or - 19%, P = 0.01, and it further decreased to 15 + or - 11% at week 10 (P = 0.0008). The percent fall in IVC 4-6 wk after the end of training was 15 + or - 11% (P = 0.87 vs. end of training). Changes in airway cells were not associated with changes in airway responsiveness. Our data show that a course of exercise training can attenuate airway responsiveness against Mch inhaled in the absence of DIs in healthy subjects and suggest that a sedentary lifestyle may favor development of airways hyperresponsiveness.

Section 2. Exercise-Induced Bronchospasm: Albuterol versus Montelukast: Highlights of the Asthma Summit 2009: Beyond the Guidelines

Exercise-induced bronchospasm (EIB) involves airway obstruction with an onset shortly after exercising. It can occur in individuals without a diagnosis of asthma, but is most common in asthmatic patients (and in this scenario may be referred to as exercise-induced asthma, EIA), correlating with the patient's degree of airway hyperreactivity. While albuterol is the most commonly used rescue and prophylactic medication for EIB, the leukotriene antagonist, monetlukast, may be an appropriate choice for some patients. Clinical data have shown that once-daily treatment with montelukast (5 or 10 mg tablet) can offer protection against EIB within 3 days for some patients. Such an approach might be preferred for patients who have difficulty with inhaled medications and for children who cannot access their inhalers during the school day. Montelukast also may be an option to reduce side effects associated with albuterol for individuals who exercise regularly.

Exercise-induced asthma: critical analysis of the protective role of montelukast

Exercise-induced asthma/exercise-induced bronchospasm (EIA/EIB) is a prevalent and clinically important disease affecting young children through older adulthood. These terms are often used interchangeably and the differences are not clearly defined in the literature. The pathogenesis of EIA/EIB may be different in those with persistent asthma compared to those with exercise-induced symptoms only. The natural history of EIA is unclear and may be different for elite athletes. Leukotriene biology has helped the understanding of EIB. The type and intensity of exercise are important factors for EIB. Exercise participation is necessary for proper development and control of EIA is recommended. Symptoms of EIB should be confirmed by proper testing. Biologic markers may also be helpful in diagnosis. Not all exercise symptoms are from EIB. Many medication and nonpharmacologic treatments are available. Asthma education is an important component of managing EIA. Many medications have been tested and the comparisons are complicated. Montelukast is a US Food and Drug Administration-approved asthma and EIB controller and has a number of potential advantages to other asthma medications including short onset of action, ease of use, and lack of tolerance. Not all patients improve with montelukast and rescue medication should be available.

Exercise-induced bronchoconstriction: The effects of montelukast, a leukotriene receptor antagonist

Exercise-induced bronchoconstriction (EIB) is very common in both patients with asthma and those who are otherwise thought to be normal. The intensity of exercise as well as the type of exercise is important in producing symptoms. This may make some types of exercise such as swimming more suitable and extended running more difficult for patients with this condition. A better understanding of EIB will allow the physician to direct the patient towards a type of exercise and medications that can result in a more active lifestyle without the same concern for resulting symptoms. This is especially important for schoolchildren who are usually enrolled in physical education classes and elite athletes who may desire to participate in competitive sports. Fortunately several medications (short- and long-acting beta(2)-agonists, cromolyn, nedocromil, inhaled corticosteroids, and more recently leukotriene modifiers) have been shown to be effective in preventing or attenuating the effects of exercise in many patients. In addition, inhaled beta(2)-agonists have been shown to quickly reverse the airway obstruction that develops in patients and continue to be the reliever medications of choice. Inhaled corticosteroids are increasingly being recommended as regular therapy now that the role of inflammation and airway injury has been identified in EIB. With the discovery that there is a release of mediators such as histamine and leukotrienes from cells in the airway following exercise with resulting airway obstruction in susceptible individuals, interest has turned to attenuating their effects with mediator antagonists especially those that block the effects of leukotrienes. Studies with an oral leukotriene antagonist, montelukast, have shown beneficial effects in adults and children aged as young as 6 years with EIB. These effects can be demonstrated as soon as two hours and as long as 24 hours after administration without a demonstrated loss of a protective effect after months of treatment. The studies leading up to and resulting in an approval of montelukast for EIB for patients aged 15 years and older are reviewed in this paper.