Assessing paediatric exercise-induced bronchoconstriction using electromyography

Introduction: Asthma is the most common chronic disease in childhood and its prevalence has increased in recent years. Although regular physical activity (PA) is considered to be beneficial for the health of asthmatics, especially children and adolescents, it can also be one of the elements that triggers asthma. This is known as exercise-induced bronchospasm (EIB), and is considered one of the factors that limits asthmatics’ participation in PA. Objective: This study aims to review the effects of physical conditioning on EIB in asthmatic children and adolescents. Methods: A systematic review was carried out on the Pubmed, Bireme and Web of Science databases, considering publications from 1998 to April 2019. Results: Eight articles were retrieved; five of the articles presented no significant difference in EIB parameters after physical training, and three demonstrated significant benefits in EIB. Conclusion: There is insufficient evidence that physical training helps reduce the frequency and severity of EIB in young asthmatics. There are still few studies that seek to show the effect of a physical training program on the improvement of EIB in children and adolescents. It is suggested that further randomized clinical trials be conducted, to investigate the effects of physical training on EIB parameters in children and adolescents. Level of Evidence II; Systematic review.

Introduction. Asthma is a common chronic disease in childhood which features bronchial hyperresponsiveness to exercise (EIB). In daily clinical practice, the report of EIB is used to assess the level of control of asthma. The asthma control questionnaire (ACQ) is a tool to evaluate the control of asthma in children. The aim of this study was to evaluate the relationship between the ACQ and EIB. Materials and methods. Two hundred children, aged 12.5 ± 2.5 years, with a pediatrician-diagnosed mild-to-moderate asthma filled out an ACQ and performed an exercise provocation test in cold air. EIB was defined as a fall in FEV1 of 15%. Results. Eighty six of the 200 children had a positive exercise challenge. There was no relationship between the categorical ACQ and the occurrence of EIB (p = .39). There was no difference in the occurrence of EIB between genders (p = .12). The positive predictive value of the ACQ for EIB was 51% and the negative predictive value for EIB was 59%. In comparison to the girls, the boys carried an odds ratio (OR) of 0.48 for having an indifferent control of asthma (p = .04; confidence interval (CI): 0.23–0.96), and an OR of 0.46 for having a not well-controlled asthma (p = .03; CI: 0.23–0.93). Conclusion. This study shows that the ACQ is not related to EIB in children with asthma. Remarkable is the percentage (41%) of children who, despite well-controlled asthma according to the ACQ, had EIB, which implies that their asthma is not well-controlled. Boys were more likely to report well-controlled asthma, although boys and girls were equally likely to have EIB.

Background: Exercise-induced bronchoconstriction (EIB) is an important and common cause of exertional dyspnoea. International guidelines recommend objective testing using indirect bronchial challenge and advocate mannitol, exercise challenge test (ECT), or eucapnic voluntary hyperpnoea (EVH). Each test should be performed using a validated method in order to ensure diagnostic accuracy. Aim: To identify current diagnostic practices in EIB and adherence to guidelines. Methods: A survey of diagnostic practice in hospitals with ‘Association for Respiratory Technology and Physiology’ accreditation. Forty-three hospitals were identified. First line bronchial challenge and standard operating procedure (SOP) documents were requested. Results: Twenty-nine of the 40 hospitals replying currently offer tests for EIB. Of these 48% offered mannitol challenge, 45% ECT, 3% full cardiopulmonary exercise testing and 3% histamine challenge. ECT SOPs were received from nine centres, none of which adhered to full recommendations for medication abstinence. All ECT SOPs used heart rate to measure exercise intensity, and a majority (89%) adhered to exercise intensity guidelines. Environmental conditions (inspired air temp and relative humidity%) are considered in 22%, and 33% adhere to recommended post-exercise lung function testing regimen. Criteria for a diagnosis of EIB varied between hospitals, with 56% of ECT SOPs specifying a fall of ≥10% as diagnostic. Conclusion: Two thirds of UK hospitals offer an indirect BCT for diagnosis of EIB. However, there is limited adherence to ECT guidelines and consequent significant variation in practice.

Exercise Challenge Test in 3- to 6-Year-Old Asthmatic Children

Objective: Parents’ awareness of their child’s asthma may improve by discussing an exercise challenge test (ECT) result with them. We investigated the influence of discussing an ECT result with parents on adherence to inhaled maintenance medication, parental illness perceptions and medication beliefs in young asthmatic children. Methods: A total of 79 children, 4–7 years old and enrolled in our standard comprehensive asthma care program, performed an ECT to assess exercise induced bronchoconstriction (EIB). The result of the ECT was immediately discussed with the parents. Median medication adherence level was measured with electronic medication loggers from six weeks before the ECT till six weeks afterwards. Parental beliefs about medicines and illness perceptions were measured with the Beliefs about Medicines Questionnaire (BMQ) and the Brief Illness Perceptions Questionnaire (B-IPQ). Results: The median baseline adherence level was high (83%) and showed a small significant decline after the ECT. There was no significant difference in the decrease in median adherence level between the children with or without EIB. Most parents (82.1%) showed a positive necessity–concern ratio at baseline, as measured with the BMQ. There was no clinical relevant change in medication concerns and necessity scores or in illness perceptions. Conclusion: Discussing ECT results with parents does not modify median adherence levels to inhaled maintenance medication nor medication beliefs of highly adherent young asthmatic children who are already enrolled in a comprehensive asthma care program.

We studied 27 non-asthmatic elite runners, mean age 22 yrs, active competitors for 9 yrs. They had run a mean distance of 3510 km during the previous year. The runners answered a respiratory-symptom questionnaire and were subjected to an exercise challenge test (ECT) in winter at subzero temperature (from -1°C to -13°C) and in summer preceded by birch pollen season (weekly total pollen grains ranged from 11 to 538 grains/m3 during the preceding month). ECT consisted of 2000 m free running at 85% of predicted maximum heart rate without warm up and forced expiratory volume in one second (FEV1) measurements immediately before and at 4, 10 and 20 min after the run. Atopy was determined by skin prick tests (SPT) with 10 air-borne allergens. Sixteen (59%) of the runners were atopic in SPT. Five (31%) of the 16 atopic runners, but none of the non-atopics had previously reported exercise-induced bronchial symptoms. The mean maximum postexercise change was -6.0% (7.0%) for atopic and +2.5% (SD 4.3%) for non-atopic runners in winter or in summer tests (t-test, p=0.0013). Significant postexercise fall in FEV1 (≥6.0%, mean-2SD) was defined from the exercise responses of those 11 symptom-free, non-atopic runners. Nine(56%) of the atopic runners had a significant fall in either winter or summer tests, six (38%) of them in winter and four (25%) in summer. In conclusion: 1) Atopic runners have a significantly greater risk for exercise-induced bronchospasm (EIB) compared with non-atopic runners. 2) ECT for studying EIB should be performed both in winter and in summer conditions. SPT is valuable tool in assessing the risk for EIB.

An exercise challenge test (ECT) that follows American Thoracic Society (ATS) guidelines is the criterion that surrogate tests for exercise-induced bronchoconstriction (EIB) should be compared (Stickland, M. et al. Annals of Allergy, Asthma & Immunology 2011; 107:229-234). Studies that have compared eucapnic voluntary hyperventilation (EVH) with ECT often fail to follow ATS guidelines. The aim of this study was to compare the airway response to EVH with the response elicited by an ECT that complied with ATS guidelines. Seventeen participants completed an ECT and an EVH test on separate days. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV 1 ), FEV 1 /FVC, and peak expiratory flow (PEF) were compared to baseline to determine the response to each challenge. Bland & Altman plot analysis was used to evaluate the bias between the mean differences for ΔFEV 1 , and to estimate a limit of agreement (LoA) within which 95% of the differences fell. The bias was 2.2% (95% CI -0.8-5.0%) indicating that ECT tended to give a ΔFEV 1 between 0.8% lower and 5% higher than EVH. The upper and lower LoA (13.7 and -9.3%, respectively) were large indicating that the ECT may result in a ΔFEV 1 ­ between 13.7% higher and 9.3% lower than EVH. Further, the confidence intervals for the upper and lower LoA (8.5 to 18.6% and -14.5 to -4.4%, respectively) were wide, also indicating poor agreement. These data do not support the use of EVH as a suitable alternative to ECT for the detection of EIB. More data is needed to fully evaluate the utility of EVH as an airway challenge.

Effects of dietary induced weight loss on exercise‐induced bronchoconstriction in overweight and obese children

To detect impacts of changes in work environment and worker-equipment interface variables upon surface electromyography (EMG) measures using multivariate, longitudinal analysis. For 33 office workers, yearly measurements (1999-2001) were taken during normal work. Independent variables were related to work environment (expert-observed equipment dimensions, work organization on questionnaire) and interface (expert-observed postures, self-reported workstation-equipment relative fit i.e. inside or outside guidelines-informed location, and 30 min video-based task analysis). Internal mechanical exposure (EMG) was recorded bilaterally from extensor carpi radialis brevis (ECRB) and upper trapezius sites, each side, also for 30 min. Dependent variables were amplitude probability distribution functions (APDF 50 and 90%) and gaptime for entire record EMG (over all tasks) and task-specific EMG (for four separate tasks). Multivariate mixed models used independent variables to predict EMG measures (4 muscle sites × (1 entire record + 4 task specific) = 20 models total). Among EMG measures, 9/16 means and 2/16 variances were significantly different across years (p < 0.1). Environment and interface variables explained part of the variation in EMG measures in 13/20 models. The most consistent predictors included: (1) increased monitor distance predicted reduced APDFs and increased gaptimes; (2) wrist extension <20° predicted decreases in left ECRB APDFs; (3) keyboard location within guidelines predicted improvements in all right ECRB EMG measures during keyboarding; and (4) longer task duration predicted higher APDFs and lower gaptimes. Longitudinal analysis with multivariate models can detect the impacts of changes in environment and interface exposures on EMG measures among office workers.

42. HEALTHY SMILE HAPPY START

Type 1 diabetes mellitus (T1D) is one of the most common chronic diseases in childhood, with its incidence increasing globally. Thecoronavirus disease 2019 (COVID-19) pandemic has been associated with an increase in severity of cases of diabetic ketoacidosis. Type 1 diabetes mellitus (T1D) is one of the most common chronic diseases in childhood, with its incidence increasing globally. Thecoronavirus disease 2019 (COVID-19) pandemic has been associated with an increase in severity of cases of diabetic ketoacidosis. A retrospective cohort study was conducted, using patients' clinical records, between March 2016 and March 2024. Thesample was divided in three groups: pre-pandemic (March 2016 to March 2020), pandemic (March 2020 to March 2021), and post-pandemic (March 2021 to March 2024). A retrospective cohort study was conducted, using patients' clinical records, between March 2016 and March 2024. Thesample was divided in three groups: pre-pandemic (March 2016 to March 2020), pandemic (March 2020 to March 2021), and post-pandemic (March 2021 to March 2024). There was an improvement in the post-pandemic period, with alower severity at presentation. However, the rate of ketoacidosis remained high, and the focus must remain on implementing preventative measures.

Background: The mechanisms of EIB have been suggested to differ between adult athletes and the general population. In line with this, FeNO has been associated with EIB in the general population, but not in adult athletes. Respiratory resistance measured by forced oscillation technique is suggested to be a more sensitive measurement of airway obstruction than FEV1. Aim: To study the association between baseline FeNO and post-exercise changes in FEV1 and respiratory resistance in adolescents either attending a sports high school or from the general population. Methods: Study group A consisted of 148 adolescents, aged 13-15 years, from the general population. Study group B consisted of 98 adolescents, aged 15-17 years, attending sports high school. The subjects performed FeNO before and FEV1 and respiratory resistance measurements at 5 Hz (R5) before and after a standardised exercise test. Results: A positive EIB test (fall in FEV1 ≥10%) was found in 48 subjects in group A and in 24 subjects in group B. FeNO related to post-exercise fall in FEV1 as well as increase in R5 in group A (rho=-0.17, p=0.04 and rho=0.34, p 0.05). Elevated FeNO (>25 ppb) was associated with EIB in group A: odds ratio (OR) 2.6 (CI 95% 1.1, 6.2), but not in group B (OR 1.0, CI 95% 0.3, 3.2). The findings in group A were consistent after adjusting for age, gender and height (aOR 2.6 CI 95% 1.1, 6.6). Conclusion: EIB in adolescent athletes is not associated with FeNO in contrast to adolescents from the general population. This indicates that the mechanisms leading to EIB in adolescent athletes may differ from the general population.

OBJETIVO: Avaliar e comparar a frequência e intensidade do broncoespasmo induzido pelo exercício (BIE) em adolescentes asmáticos obesos e não-obesos. MÉTODOS: Estudo transversal e descritivo realizado com 39 adolescentes de ambos os sexos, com idade entre dez e 16 anos, divididos em dois grupos conforme o histórico clínico de asma e/ou rinite alérgica e o índice de massa corporal: asmáticos obesos (n=18); asmáticos não-obesos (n=21). Utilizou-se o teste de broncoprovocação com exercício para a avaliação do BIE, considerando-se positiva uma diminuição do volume expiratório forçado no primeiro segundo (VEF1) &gt;15% do valor pré-exercício. Para avaliar a intensidade e a recuperação do BIE, foram calculadas a queda percentual máxima do VEF1 (QM%VEF1) e a área acima da curva (AAC0-30). A análise estatística utilizou o teste exato de Fischer para comparar a frequência de BIE e o teste de Mann-Whitney para a intensidade e recuperação. Rejeitou-se a hipótese de nulidade se p&lt;0,05. RESULTADOS: Não houve diferença significativa na frequência de BIE entre os grupos de asmáticos obesos (50%) e não-obesos (38%). Entretanto, a queda máxima do VEF1 e a AAC0-30 foram maiores nos asmáticos obesos em comparação aos não-obesos (respectivamente 37,7% e 455 versus 24,5% e 214, p&lt;0,03). CONCLUSÕES: A obesidade não contribuiu para o aumento da frequência do BIE em asmáticos e não-asmáticos, entretanto, a obesidade contribuiu para o aumento da intensidade e do tempo de recuperação da crise de BIE em asmáticos

Lower extremity injuries have immediate and long-term consequences. Lower extremity movement assessments can assist with identifying individuals at greater injury risk and guide injury prevention interventions. Movement assessments identify similar movement characteristics and evidence suggests large magnitude kinematic relationships exist between movement patterns observed across assessments; however, the magnitude of the relationships for electromyographic (EMG) measures across movement assessments remains largely unknown. This study examined relationships between lower extremity kinematic and EMG measures during jump landings and single leg squats. Lower extremity three-dimensional kinematic and EMG data were sampled from healthy adults (males = 20, females = 20) during the movement assessments. Pearson correlations examined the relationships of the kinematic and EMG measures and paired samples t-tests compared mean kinematic and EMG measures between the assessments. Overall, significant moderate correlations were observed for lower extremity kinematic (ravg = 0.41, rrange = 0.10–0.61) and EMG (ravg = 0.47, rrange = 0.32–0.80) measures across assessments. Kinematic and EMG measures were greater during the jump landings. Jump landings and single leg squats place different demands on the body and necessitate different kinematic and EMG patterns, such that these measures are not highly correlated between assessments. Clinicians should, therefore, use multiple assessments to identify aberrant movement and neuromuscular control patterns so that comprehensive interventions can be implemented.

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