Exercise-induced bronchoconstriction by ethnicity and presence of asthma in British nine year olds

Sex Differences in the Prevalence and Severity of Exercise-Induced Bronchoconstriction in Kindergarteners in Japan

BACKGROUND

Exercise-induced bronchoconstriction (EIB), a strong positive predictor of asthma, becomes progressively less frequent with age. Although asthma tends to become less common only in boys during adolescence, sex differences in EIB, especially in preschoolers, remain unclear. To find EIB for early diagnosis and intervention asthma, mass-screening tests considering sex differences in preschoolers are needed. In this study, we investigated whether sex differences influence the prevalence and severity of EIB in prepubertal children aged 5-6 years.

METHODS

Fifty-one children aged 5-6 years who were attending a kindergarten in Matsuyama City, Ehime, Japan, were enrolled in this cross-sectional study. The children underwent a 6-minute free-running test in 2015. The peak expiratory flow rate (PEFR) was measured before exercise and 0, 3, 10, and 20 minutes after exercise. The severity of EIB was classified according to the reduction in PEFR, measured as the difference between the postexercise PEFR and the highest pre-exercise PEFR.

RESULTS

Of the 51 children (23 boys and 28 girls) enrolled, the prevalence of EIB defined as three criteria: a ≥15%, ≥20%, or ≥25% decrease was 54.9% (28/51), 41.2% (21/51), and 25.5% (13/51), respectively. The prevalence of EIB defined as ≥25% decrease was significantly higher in girls than in boys (39.3% vs 8.7%, P = .013). In girls, the mean percentage change in PEFR was significantly higher 20 minutes than 10 minutes postexercise (P = .043).

CONCLUSIONS

Sex difference in the prevalence and severity of EIB should be considered when evaluating EIB, even in young, prepubertal children.

Qualitative study to identify ethnicity-specific perceptions of and barriers to asthma management in South Asian and White British children with asthma

OBJECTIVE

This paper draws on the data from the Management and Interventions for Asthma (MIA) study to explore the perceptions and experiences of asthma in British South Asian children using semi-structured interviews. A comparable cohort of White British children was recruited to identify whether any emerging themes were subject to variation between the two groups so that generic and ethnicity-specific themes could be identified for future tailored intervention programmes for South Asian children with asthma.

SETTING

South Asian and White British children with asthma took part in semi-structured interviews in Leicester, UK.

PARTICIPANTS

Thirty three South Asian and 14 White British children with asthma and aged 5-12 years were interviewed.

RESULTS

Both similar and contrasting themes emerged from the semi-structured interviews. Interviews revealed considerable similarities in the experience of asthma between the South Asian and White British children, including the lack of understanding of asthma (often confusing trigger with cause), lack of holistic discussions with healthcare professionals (HCPs), an overall neutral or positive experience of interactions with HCPs, the role of the family in children's self-management and the positive role of school and friends. Issues pertinent to South Asian children related to a higher likelihood of feeling embarrassed and attributing physical activity to being a trigger for asthma symptoms.

CONCLUSIONS

The two ethnicity-specific factors revealed by the interviews are significant in children's self-management of asthma and therefore, indicate the need for a tailored intervention in South Asian children.

Exercise-induced bronchoconstriction: prevalence, pathophysiology, patient impact, diagnosis and management

Exercise-induced bronchoconstriction (EIB) can occur in individuals with and without asthma, and is prevalent among athletes of all levels. In patients with asthma, symptoms of EIB significantly increase the proportion reporting feelings of fearfulness, frustration, isolation, depression and embarrassment compared with those without symptoms. EIB can also prevent patients with asthma from participating in exercise and negatively impact their quality of life. Diagnosis of EIB is based on symptoms and spirometry or bronchial provocation tests; owing to low awareness of EIB and lack of simple, standardised diagnostic methods, under-diagnosis and mis-diagnosis of EIB are common. To improve the rates of diagnosis of EIB in primary care, validated and widely accepted symptom-based questionnaires are needed that can accurately replicate the current diagnostic standards (forced expiratory volume in 1 s reductions observed following exercise or bronchoprovocation challenge) in patients with and without asthma. In patients without asthma, EIB can be managed by various non-pharmacological methods and the use of pre-exercise short-acting β2-agonists (SABAs). In patients with asthma, EIB is often associated with poor asthma control but can also occur in individuals who have good control when not exercising. Inhaled corticosteroids are recommended when asthma control is suboptimal; however, pre-exercise SABAs are also widely used and are recommended as the first-line therapy. This review describes the burden, key features, diagnosis and current treatment approaches for EIB in patients with and without asthma and serves as a call to action for family physicians to be aware of EIB and consider it as a potential diagnosis.

Global prevalence of exercise-induced bronchoconstriction in childhood: A meta-analysis

AIM

This systematic review and meta-analysis aimed to estimate the global prevalence of exercise-induced bronchoconstriction (EIB) in children and adolescents.

METHOD

We searched PubMed, Google Scholar, and the Virtual Health Library-BIREME from inception to December 23, 2017. We selected observational studies that reported the prevalence of EIB (diagnosed by exercise challenge test) in children and adolescents aged 5-18 years. We conducted random-effects meta-analyses to estimate the pooled prevalence of EIB and 95% CI.

RESULTS

We included 66 studies (55 696 participants, 5670 cases of EIB) in the review, of which 33 in general population of children and adolescents, 10 in child and adolescent athletes and 23 in children and adolescents with asthma. The global mean prevalence of EIB in the general population of children and adolescents was 9% (IC95%: 8-10%), with a higher rate (12%) in Asia-Pacific and America. The mean prevalence of EIB was 15% (95% CI: 9-21%) in child and adolescent athletes, and 46% (95% CI: 39-53%) in children and adolescents with asthma. We estimated that, globally, around 16.5 million (95% CI: 15-18 million) children and adolescents up to 18 years of age may have EIB.

CONCLUSION

EIB in childhood should be considered as a global public health problem that needs more attention. The substantial heterogeneity between studies highlights the need for evidence-based guidelines for diagnosis of EIB in this age group.

Accuracy of optoelectronic plethysmography in childhood exercise-induced asthma

OBJECTIVE

To assess the variations of end-expiratory volume of chest wall (EEVcw) measured by optoelectronic plethysmography (OEP) as a diagnostic tool in exercise-induced asthma (EIA) among asthmatic preschool children.

METHODS

Forty children diagnosed with asthma were included in the study. Spirometry was used as a gold standard test for comparison with OEP. A 10% decline in forced expiratory volume in 1 second was considered positive for EIA. OEP was performed with 8 cameras at a frequency of 60 Hz and 89 markers were placed on the thoraco-abdominal surface of participants. Following bronchoprovocation testing on a treadmill, series of OEP and spirometry were conducted between 5 and 30 minutes after exercise. To obtain the ideal cut-off point, a receiver operating characteristic (ROC) curve was constructed for the largest EEVcw. The highest Youden index was used as criteria to obtain the cut-off point with the best sensitivity and specificity.

RESULTS

Of the 40 children studied, 16 had EIA. According to the ROC curve, the cut-off point of 0.185% for EEWcw provided mean sensitivity (95% confidence interval) of 93.75% (0.69-0.99), for a specificity of 83.33% (0.63-0.95), when using the largest increase in the period of 5-30 minutes post-exercise. The low area of the ROC was 0.93 (0.85-1.00) for p < 0.001.

CONCLUSION

OEP can be accurately used to replace spirometry in asthmatic children unable to adequately execute the required manoeuvres.

Exercise-induced bronchoconstriction update-2016

The first practice parameter on exercise-induced bronchoconstriction (EIB) was published in 2010. This updated practice parameter was prepared 5 years later. In the ensuing years, there has been increased understanding of the pathogenesis of EIB and improved diagnosis of this disorder by using objective testing. At the time of this publication, observations included the following: dry powder mannitol for inhalation as a bronchial provocation test is FDA approved however not currently available in the United States; if baseline pulmonary function test results are normal to near normal (before and after bronchodilator) in a person with suspected EIB, then further testing should be performed by using standardized exercise challenge or eucapnic voluntary hyperpnea (EVH); and the efficacy of nonpharmaceutical interventions (omega-3 fatty acids) has been challenged. The workgroup preparing this practice parameter updated contemporary practice guidelines based on a current systematic literature review. The group obtained supplementary literature and consensus expert opinions when the published literature was insufficient. A search of the medical literature on PubMed was conducted, and search terms included pathogenesis, diagnosis, differential diagnosis, and therapy (both pharmaceutical and nonpharmaceutical) of exercise-induced bronchoconstriction or exercise-induced asthma (which is no longer a preferred term); asthma; and exercise and asthma. References assessed as relevant to the topic were evaluated to search for additional relevant references. Published clinical studies were appraised by category of evidence and used to document the strength of the recommendation. The parameter was then evaluated by Joint Task Force reviewers and then by reviewers assigned by the parent organizations, as well as the general membership. Based on this process, the parameter can be characterized as an evidence- and consensus-based document.

Transdisciplinary research strategies for understanding socially patterned disease: the Asthma Coalition on Community, Environment, and Social Stress (ACCESS) project as a case study

As we have seen a global increase in asthma in the past three decades it has also become clear that it is a socially patterned disease, based on demographic and socioeconomic indicators clustered by areas of residence. This trend is not readily explained by traditional genetic paradigms or physical environmental exposures when considered alone. This has led to consideration of the interplay among physical and psychosocial environmental hazards and the molecular and genetic determinants of risk (i.e., biomedical framing) within the broader socioenvironmental context including socioeconomic position as an upstream "cause of the causes" (i.e., ecological framing). Transdisciplinary research strategies or programs that embrace this complexity through a shared conceptual framework that integrates diverse discipline-specific theories, models, measures, and analytical methods into ongoing asthma research may contribute most significantly toward furthering our understanding of socially patterned disease. This paper provides an overview of a multilevel, multimethod longitudinal study, the Asthma Coalition on Community, Environment and Social Stress (ACCESS), as a case study to exemplify both the opportunities and challenges of transdisciplinary research on urban asthma expression in the United States.

Post-exercise airway narrowing in healthy primary school children

Changes in lung function after exercise in healthy primary school children have mostly been described in field studies. More complete description and insight into relevant mechanisms may be provided in lung function laboratory. The aim was to describe airway caliber and response to deep inhalation (DI) after exercise in healthy primary school children. Respiratory resistance (Rrs) by the forced oscillation technique and spirometry were measured before and after exercise in 50 healthy primary school children. The Rrs response to DI was assessed in 31 subjects, assuming a significantly larger decrease in Rrs after exercise would attest relief of exercise-induced airway smooth muscle contraction. Measurements were taken before, 5 min (E5) and 15 min (E15) after exercise. Significantly larger Rrs and lower forced expiratory volume in 0.5 s were observed at E5 versus baseline or E15 (p < 0.05). DI induced significant decrease in Rrs (p = 0.01) that was not different between E5 and baseline. Healthy primary school children exhibit changes in Rrs and spirometry after exercise indicating small but significant airway narrowing. The response to DI similar at baseline and E5 suggests airway narrowing from hyperemia in the bronchial wall rather than airway smooth muscle constriction.

Pediatric anesthesia and recent developments in asthma in children

Asthma is a chronic inflammatory disease and the physiological consequence is bronchial hyperresponsiveness to different stimuli. With the worldwide increase in the prevalence of asthma, an increased number of asthmatics are likely to require anesthesia for surgical procedures. Recent investigations described the role played by different environmental agents in asthma, and clarified assessment and management strategies which can be applied to anesthesia in order to decrease the morbidity related to perioperative bronchospasm in children with asthma.

Applicability of interrupter resistance measurements for evaluation of exercise-induced bronchoconstriction in children

The interrupter technique is a noninvasive method for measuring air-flow resistance during tidal breathing. This method requires minimal cooperation, and is therefore promising for use in uncooperative children. The aim of this study was to evaluate applicability interrupter resistance (Rint) measurements in the assessment of exercise-induced bronchoconstriction (EIB). Fifty children aged 5-12 years with mild to moderate asthma were tested by exercise challenge, consisting of free outdoor running for 6 min at 80-90% of maximal predicted heart rate for age. Rint, forced expiratory volume in 1 sec (FEV1), and peak expiratory flow (PEF) were measured before and 10 min after exercise. EIB was defined as a fall of 10% or more in FEV1 after exercise. The repeatability of Rint was assessed, and its response to exercise challenge was compared with current standardized methods. The mean intermeasurement coefficient of variation was 4.6% (SD, +/- 3.0%), and the repeatability coefficient was 0.056 kPa/l/sec. Eighteen (36%) of the 50 children had EIB after exercise challenge test. The area under the receiver-operating characteristic (ROC) curve was 0.953 (95% confidence interval, 0.853-0.992; P < 0.001), and the optimal Rint cutoff value was 15.2%, producing a sensitivity of 88.9% and a specificity of 96.9%. The positive and negative predictive values were 94.1% and 93.9%, respectively. The kappa value between FEV1 and Rint was 0.83. The repeatability of Rint measurements was good, and the results of exercise challenge tests using Rint measurements have excellent agreement with the current standardized methods to detect EIB. Considering that only minimal comprehension and coordination are needed without forced breathing technique, the Rint measurement can provide a useful alternative for assessment of EIB in children unable to perform reliable spirometry.

Ethnic variations in UK asthma frequency, morbidity, and health-service use: a systematic review and meta-analysis

BACKGROUND

The frequency of asthma varies between countries, and may also vary between ethnic groups in more geographically confined areas. We sought evidence of such ethnic variations in the UK for asthma frequency, morbidity, and health-services use, and to understand possible reasons for any differences.

METHODS

We searched MEDLINE, EMBASE, CINAHL, PSYCHInfo, PREMEDLINE, HEALTHSTAR, Cambridge Register of Conference Abstracts, the Dissertation and Thesis Database, and the National Registry of Research. Additionally, we searched the bibliographies of reports identified and websites of health authorities, and contacted experts in this discipline. Our main outcomes were comparisons of asthma rate, morbidity, and health-services use. We did meta-analyses using random-effects models.

FINDINGS

13 studies contained relevant data. All prevalence studies were of children and showed that south Asian children had a lower frequency of symptoms suggestive of asthma compared with black and white children (pooled rate of history of wheeze in the previous 12 months: south Asians 9.6% [95%CI 8.0-11.2%], black people 16.2% [12.8-19.6%], white people 14.6% [11.5-17.8%]). The pooled frequency of clinician-diagnosed asthma in children followed a similar pattern (south Asians 7.6% [3.7-11.4%], black people 15.0% [3.5-26.5%], white people 10.6% [4.6-16.7%]. However, relative to white people, the risk of admission for asthma in children and adults was higher for south Asians (odds ratio 2.9 [2.4-3.4]) and black people (2.1 [1.8-2.5]).

INTERPRETATION

The differences in admission are not explained by differences in asthma frequency between groups; they could relate to ethnic variations in asthma severity, differences in health-seeking behaviour, or difficulties in accessing high-quality primary care services.

Activity-induced asthma

Exercise is the most common trigger of persistent childhood asthma. The history for EIA can be complicated by the lack of perception of significant airway obstruction during exercise. One must carefully identify those children with EIA from the group of children who report low level of activity because of lack of interest or because they are out of shape. Baseline spirometry of children with persistent asthma is frequently normal. Spirometry is important to identify those children with EIA who underrecognize their disease, but normal results should not be used as evidence of absence of disease. Formal exercise testing should be considered when the diagnosis is unclear or if there seems to be a lack of bronchoprotection with inhaled albuterol. The goal of treatment of EIA should be the attainment of a normal activity level for children and adolescents. Identification of the limits imposed by EIA and establishment of goals of therapy with the child and family should be the initial action. Inactivity or reduced exertion, in the presence of this diagnosis. should not be accepted. Therapy for EIA starts with control of the underlying persistent asthma. Inhaled corticosteroids are the most effective initial treatment of both EIA and persistent asthma in children and adolescents. Exercise-induced asthma is a common aspect of a prevalent disease that warrants proper diagnosis and treatment. With appropriate therapy, children with EIA should be able to participate in sports and maintain normal activity. They should strive to compete in the same playing field as their peers and have the same goals as those children and athletes who do not have exercise-induced asthma.

What do parents of wheezy children understand by "wheeze"?

BACKGROUND

Reported wheeze is the cornerstone of asthma diagnosis.

AIMS

To determine what parents understand by wheeze.

METHODS

Two studies were undertaken: (1) Parents of clinic attendees with reported wheeze (n=160) were asked by questionnaire what they understood by "wheeze" and how they knew their child was wheezy. Responses were compared to definitions of wheeze in 12 epidemiology studies and their response options. (2) The extent of agreement of parents' reports (n=139) of acute wheezing in their children and clinicians' findings of "wheeze" and "asthma" was examined.

RESULTS

(1) "Sound" and "difficulty in breathing" were perceived central to "wheeze". "What you hear" was not selected by 23% (95% confidence interval (CI) 16-30%). "Whistling" was mentioned by 11% (CI 6-15%) but featured in 11 of 12 epidemiology questionnaires. (2) There was les than 50% agreement between parents' and clinicians' reports of wheeze and asthma.

CONCLUSIONS

Conceptual understandings of "wheeze" for parents of children with reported wheeze are different from epidemiology definitions. Parents' reports of acute wheeze and clinicians' findings also differ.

Proventil HFA prevents exercise-induced bronchoconstriction in children

Short-acting inhaled beta2-agonists used just prior to exercise are an effective method for preventing exercise-induced bronchoconstriction (EIB) in children. This was a randomized, single-blind, placebo-controlled, four-period crossover study that compared the effectiveness of albuterol formulated in hydrofluoroalkane-134a (HFA) to albuterol formulated in chlorofluorocarbons (CFCs) and to placebo in protecting asthmatic children age 6-11 from EIB. Patients self-administered either HFA albuterol, two different CFC albuterol products, or placebo 30 min prior to exercise challenge. Spirometry was performed predose and 5, 10, 15, 30, 45, 60, 75, and 90 min after the exercise challenge was completed. The smallest percent change from the predose forced expiratory volume in 1 sec (FEV1) after exercise challenge was similar for the three active treatments, and each of the active treatments was significantly better than placebo. Each active treatment had significantly fewer patients unprotected from EIB (unprotected defined as having >20% fall in FEV1 after exercise challenge) than placebo. Changes in heart rate, blood pressure and electrocardiogram (ECG) intervals were similar for the three active treatments following exercise. HFA albuterol is as effective as albuterol products formulated in CFCs and more effective than placebo in protecting asthmatic children from EIB.