Exercise Challenge Test Research Articles

Can Pediatricians Assess Exercise-Induced Bronchoconstriction From Post-exercise Videos?

Objective: Exercise-induced bronchoconstriction (EIB) is a highly prevalent morbidity of childhood asthma and defined by a transient narrowing of the airways during or after physical exercise. An exercise challenge test (ECT) is the reference standard for the diagnosis of EIB. Video evaluation of EIB symptoms could be a practical alternative for the assessment of EIB. We studied the ability of pediatricians to assess EIB from post-exercise videos.Methods: A clinical assessment was performed in 20 asthmatic children (mean age 11.6 years) and EIB was measured with a standardized ECT performed in cold, dry air. EIB was defined as a fall in forced expiratory volume in 1 s (FEV1) of ≥10% post-exercise. Children were filmed before and after exercise in frontal position and bare chested. The clinical assessment results and videos were shown to 20 pediatricians (mean experience 14.4 years). Each assessed EIB severity in 5 random children providing 100 assessments, scored on a continuous rating scale (0–10) and in severity classifications (no, mild, moderate, severe) using a scoring list including physical asthma symptoms. Correlations between predicted scores and objective scores were calculated with Spearman's rho and Cohen's Kappa. A generalized linear model was used to assess the relationship between physical symptoms and fall in FEV1.Results: Median fall in FEV1 after exercise was 15.1% (IQR 1.2–65.1). Pediatricians detected EIB with a sensitivity of 78% (95% CI 66–87%) and a specificity of 40% (95% CI 27–55%). The positive predictive value for a pediatricians' diagnosis of EIB was 61% (95% CI 50–72%). The negative predictive value was 60% (95% CI 42–76%). The agreement between predicted EIB severity classifications and the validated classifications based on the ECT's, was fair [Kappa = 0.36 (95% CI 0.23–0.48)]. The correlation between predicted EIB severity scored on a continuous rating scale and fall in FEV1 after exercise was weak (rs = 0.39, p < 0.001). Independent predictive variables for fall in FEV1 were wheezing (−11%), supraclavicular retractions (−8.4%) and a prolonged expiratory phase (−8.8%).Conclusion: The ability of pediatricians to assess EIB from post-exercise videos is fair at best, implicating that standardized ECT's are still vital in the assessment of EIB.

EXERCISE INDUCED BRONCHOCONSTRICTION IN MEDICAL STUDENTS

INTRODUCTION: Exercise induced bronchoconstriction (EIB) is transient narrowing of lower respiratory tract airways after exercise. It affects about 5 to 20 % of healthy individuals and 80% of Asthmatics. Obesity has been considered as one of the risk factor to the development of EIB. Symptoms of EIB are nonspecific and can be seen in a variety of disorders and studies have shown a lack of diagnosis specificity and sensitivity based on symptoms. AIM: The aim of this study was to evaluate frequency of EIB in Medical students of Govt. Medical College Miraj. We also tried to find out association of body mass index (BMI) with EIB. We also tried to find out correlation of subjective feeling of breathlessness (symptom of EIB) with actual findings of spirometry tests used to asses EIB. METHOD: This cross-sectional observational study was conducted on 80 male medical students. Exercise challenge test was conducted for participants. Pre and post-test values of Forced expiratory volume in one second (FEV1) and Peak expiratory flow rate (PEFR) were compared and students with ≥ 10% decrease in post-test FEV1 &amp; PEFR were considered positive cases of exercise induced bronchoconstriction. Statistical analysis was done by using software, IBM-SPSS VER 20. RESULT:In our study frequency of EIB in medical students was 6.4%. Decrease in post-test FEV1 and PEFR values were statistically significant with Pvalue &lt; 0.001. Our findings show that there was no association between BMI and EIB. Our study results also reveal strong correlation between subjective feeling of breathlessness measured in terms of visual analogue scale (VAS) and objective spirometry tests used to assess EIB. CONCLUSION: EIB is one of the major problems to be addressed as increasing frequency of EIB in healthy population could pose a threat when people attempt exercise training for their health benefits. Proper care with physician's consultation can minimize undue risks associated with EIB in healthy people.

EXERCISE INDUCED BRONCHOCONSTRICTION IN MEDICAL STUDENTS

INTRODUCTION: Exercise induced bronchoconstriction (EIB) is transient narrowing of lower respiratory tract airways after exercise. It affects about 5 to 20 % of healthy individuals and 80% of Asthmatics. Obesity has been considered as one of the risk factor to the development of EIB. Symptoms of EIB are nonspecific and can be seen in a variety of disorders and studies have shown a lack of diagnosis specificity and sensitivity based on symptoms. AIM: The aim of this study was to evaluate frequency of EIB in Medical students of Govt. Medical College Miraj. We also tried to find out association of body mass index (BMI) with EIB. We also tried to find out correlation of subjective feeling of breathlessness (symptom of EIB) with actual findings of spirometry tests used to asses EIB. METHOD: This cross-sectional observational study was conducted on 80 male medical students. Exercise challenge test was conducted for participants. Pre and post-test values of Forced expiratory volume in one second (FEV1) and Peak expiratory flow rate (PEFR) were compared and students with ≥ 10% decrease in post-test FEV1 &amp; PEFR were considered positive cases of exercise induced bronchoconstriction. Statistical analysis was done by using software, IBM-SPSS VER 20. RESULT:In our study frequency of EIB in medical students was 6.4%. Decrease in post-test FEV1 and PEFR values were statistically significant with Pvalue &lt; 0.001. Our findings show that there was no association between BMI and EIB. Our study results also reveal strong correlation between subjective feeling of breathlessness measured in terms of visual analogue scale (VAS) and objective spirometry tests used to assess EIB. CONCLUSION: EIB is one of the major problems to be addressed as increasing frequency of EIB in healthy population could pose a threat when people attempt exercise training for their health benefits. Proper care with physician's consultation can minimize undue risks associated with EIB in healthy people.

The Visual Analog Scale detects exercise-induced bronchoconstriction in children with asthma

Objective: Exercise-induced bronchoconstriction (EIB) is a specific morbidity of childhood asthma and an important sign of uncontrolled asthma. The occurrence of EIB is insufficiently identified by the Childhood Asthma Control Test (C-ACT) and Asthma Control Test (ACT). This study aimed to (1) evaluate the Visual Analog Scale (VAS) for dyspnea as a tool to detect EIB in asthmatic children and (2) assess the value of combining (C-)ACT outcomes with VAS scores. Methods: We measured EIB in 75 asthmatic children (mean age 10.8 years) with a standardized exercise challenge test (ECT) performed in cold and dry air. Children and parents reported VAS dyspnea scores before and after the ECT. Asthma control was assessed by the (C-)ACT. Results: Changes in VAS scores (ΔVAS) of children and parents correlated moderately with fall in forced expiratory volume in 1 second (FEV1), respectively rs=0.57 (p < .001) and rs=0.58 (p < .001). At a ΔVAS cutoff value of ≥3 in children, sensitivity and specificity for EIB were 80% and 79% (AUC 0.82). Out of 38 children diagnosed with EIB, 37 had a (C-)ACT score of ≤19 and/or a ΔVAS of ≥3, corresponding with a sensitivity of 97% and a negative predictive value of 96%. Conclusion: This study shows that the VAS could be an effective additional tool for diagnosing EIB in children. A reported difference in VAS scores of ≥3 after a standardized ECT combined with low (C-)ACT scores was highly effective in detecting and excluding EIB.

Association of air humidity with incidence of exercise-induced bronchoconstriction in children.

The effects of humidity and temperature on results of free running test in children are not known. Assess the relation of outdoor air temperature, relative humidity (RH), and absolute humidity (AH) to airway obstruction in children after free running exercise test. We analyzed all exercise challenge tests with impulse oscillometry in children between January 2012 and April 2015 in the Tampere University Hospital. The associations of AH, RH, and temperature of outdoor air with change in airway resistance were studied using regression analysis and by comparing the frequency of exercise-induced bronchoconstriction (increase ≥40% in resistance at 5 Hz) at different levels of temperature and humidity. Overall, 868 children with reliable results were included (mean age: 5.4 years; range: 3.0-14.1). In regression analysis, the relative change in resistance at 5 Hz after exercise was related to temperature (regression coefficient = -0.223, P = .020) and AH (regression coefficient = -0.893, P = .002), but not to RH. If absolute air humidity was <5 g/m3 , exercise-induced bronchoconstriction (EIB) occurred in 17.6% of study subjects and at AH levels ≥10 g/m3 , it occurred in 5.9% of study subjects (P = .008). In multiple regression analysis comparing the effects of temperature and humidity and adjusting for covariates, only AH was independently associated with change in airway resistance (P = .009). High AH of air is associated with lower incidence of EIB after outdoor exercise test in children. A negative test result at AH ≥10 g/m3 should be interpreted with caution.

93 Comparison of physiological responses to exercise in horses on a conditioning regimen versus inactive horses receiving a yucca and fenugreek dietary supplement

Abstract Yucca and fenugreek are purported to reduce inflammation and improve metabolic response to exercise. Therefore, we evaluated the effects of a dietary supplement (DigestaWell NRG) in unconditioned horses completing an exercise challenge test. In this study, 10 unfit horses were assigned to receive exercise (EXC; n = 5) or the dietary supplement (SUP; n = 5). Horses assigned to EXC were ridden daily at a walk, trot, and canter. Horses assigned to SUP were ridden once per week at a walk and slow trot, but received no other exercise. Horses underwent a 14-min standardized exercise test (5 min walk, 5 min trot, 4 min canter) prior to (Period1) and after a 4-wk treatment period (Period2). Heart rate, respiration rate, blood lactate concentrations, and thermal images of six muscle groups were obtained prior to, immediately after, and 2 hr post-test. Data were analyzed using repeated measures ANOVA. During Period1, similar (P &gt; 0.05) post-exercise increases in heart rate, respiration rate, blood lactate, and thermal images were observed regardless of treatment group. During Period2, SUP horses had lower (P &lt; 0.001) lactate concentrations than EXC horses at 2 hr post exercise, and it is possible that these lower concentrations are responsible for lower peripheral temperatures. Infrequently exercised horses may benefit from yucca and fenugreek supplementation due to the observed effect of these herbs to reduce post-exercise lactate concentrations and peripheral temperatures.

44 Comparison of physiological responses to exercise in horses on a conditioning regimen versus inactive horses receiving a yucca and fenugreek dietary supplement

Abstract Yucca and fenugreek are purported to reduce inflammation and improve metabolic response to exercise. Therefore, we evaluated the effects of a dietary supplement (DigestaWell NRG) in unconditioned horses completing an exercise challenge test. In this study, 10 unfit horses were assigned to receive exercise (EXC; n = 5) or the dietary supplement (SUP; n = 5). Horses assigned to EXC were ridden daily at a walk, trot, and canter. Horses assigned to SUP were ridden once per week at a walk and slow trot, but received no other exercise. Horses underwent a 14-min standardized exercise test (5 min walk, 5 min trot, 4 min canter) prior to (Period1) and after a 4-wk treatment period (Period2). Heart rate, respiration rate, blood lactate concentrations, and thermal images of six muscle groups were obtained prior to, immediately after, and 2 hr post-test. Data were analyzed using repeated measures ANOVA. During Period1, similar (P &gt; 0.05) post-exercise increases in heart rate, respiration rate, blood lactate, and thermal images were observed regardless of treatment group. During Period2, SUP horses had lower (P &lt; 0.001) lactate concentrations than EXC horses at 2 hr post exercise, and it is possible that these lower concentrations are responsible for lower peripheral temperatures. Infrequently exercised horses may benefit from yucca and fenugreek supplementation due to the observed effect of these herbs to reduce post-exercise lactate concentrations and peripheral temperatures.

Breath Carbon Monoxide Concentration”, An Indicator of Early Airway Inflammation in Asymptomatic Smokers

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Perceptions of Asthma and Exercise, and Associations With Weight Status and Asthma Morbidity in Urban Children

BackgroundGiven the high prevalence of asthma and obesity in minority children, there is a need to identify targets for intervention to decrease the impact of these conditions on children's functioning in this high-risk group. ObjectiveTo examine in urban children with persistent asthma, 1) differences in asthma indicators (eg, FEV1% predicted) by weight status, and by ethnic group/weight status, 2) caregivers’ fears about their child's asthma by weight status, and by ethnic group/weight status, and 3) the proportion of children who qualified for exercise-induced bronchospasm (EIB) via exercise challenge test among those whose caregivers endorse exercise as a trigger for asthma. MethodsIn this sample of urban children (aged 7–9; N = 147), subjective measures included child/caregiver daily report of asthma symptoms and caregiver fears about their child's asthma. Objective lung function was measured twice daily via handheld spirometer and EIB was confirmed via exercise challenge test. ResultsIn the overall sample, a greater proportion of normal-weight children reported asthma symptoms compared to overweight/obese children. Caregiver fears about asthma were more prevalent among Latino caregivers. Non-Latino White children whose caregivers were afraid their child may die when having asthma reported more days with asthma symptoms. Very few children had confirmed EIB compared to the proportion of caregivers who endorsed exercise as a dangerous trigger for asthma. ConclusionsCaregiver fear about asthma and misperceptions of exercise as a dangerous trigger for asthma should be addressed during health care visits with families of children with asthma and interventions including urban children with asthma.

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

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

(300) Neuropeptide Y and ALLO: Potential Neurobiological Mediators of Exercise Benefits for Pain Sensitivity in Chronic Pain and PTSD: Preliminary CDA2 Findings

This study assessed the effects of acute exercise challenge testing (MAX-EX), as well as progressive exercise training, on Neuropeptide Y (NPY) and ALLO, two anti-stress and anti-nociceptive neurohormones, according to their relationship with pain sensitivity in a male and female population of civilians and Veterans with comorbid chronic pain and PTSD. The pilot sample (N=5) was 40% male (n=2), 60% female (n=3) with mean age of 35 years. Before exercise training, there were only small, non-significant positive correlations between MAX-EX test-induced increases in NPY or ALLO and indices of pain sensitivity (pain threshold and tolerance) assessed via a cold pressor test performed 30’ after the MAX-EX test (Δ NPY with pain threshold: =.36, p=.43; ΔALLO with pain tolerance: =-.37, p=.47). After exercise training, correlations between MAX-EX test-induced increases in NPY or ALLO and indices of pain sensitivity were high (ΔNPY with pain threshold: =.96, p

Airway hyperresponsiveness in young children with respiratory symptoms: A five-year follow-up

BackgroundRecurrent wheezing in early life is transient in most children. The significance of airway hyperresponsiveness (AHR) in persistence of respiratory symptoms from infancy to early childhood is controversial. ObjectiveWe evaluated whether AHR in wheezy infants predicts doctor-diagnosed asthma (DDA) or AHR at the age of 6 years. MethodsSixty-one wheezy infants (age 6-24 months) were followed up to the median age of 6 years. Lung function and AHR with methacholine challenge test were assessed at infancy and 6 years. The exercise challenge test was performed at the age of 6 years. Atopy was assessed with skin prick tests. ResultsAt 6 years, 21 (34%) of the children had DDA. Children with DDA had higher logarithmic transformed dose-response slope (LOGDRS) to methacholine in infancy than children without DDA (0.047 vs 0.025; P = .033). Furthermore, AHR to methacholine in infancy and at 6 years were associated with each other (r = 0.324, P = .011). Children with exercise-induced bronchoconstriction (EIB) at 6 years were more reactive to methacholine in infancy than those without EIB (P = .019). ConclusionIncreased AHR in symptomatic infants was associated with increased AHR, DDA, and EIB at median the age of 6 years, suggesting early establishment of AHR.

Study of Serum Level of Lipoxin A4 in Exercise-Induced Bronchoconstriction in Asthmatic Children

AbstractBackground: Asthma is a chronic lung disease character-ized by wheezy chest, resulting from allergic inflammation and hyperresponsivness of the bronchi to various stimuli. Exercise-induced broncho constriction is a common manifes-tation of asthma in children and adolescents, occurring in up to 90% of asthmatic children. Lipoxins are the first agents determined to be anti-inflammatory endogenous lipid mediators involved in the resolution of inflammation. Since there is defective lipoxin biosynthesis in patients with severe asthma, we hypothesized that Lipoxin A4 may be related to develop-ment of exercise induced bronchoconstriction.Aim of Study: It was to measure serum level of lipoxin A4 before and after exercise to evaluate its role in exercise induced bronchoconstriction in asthmatic children.Patients and Methods: The study was carried out on fifteen children with mild intermittent or mild persistant asthma with positive response to exercise challenge test and fifteen children with mild intermittent or mild persistant asthma with negative response to exercise challenge test who attended to the outpatient clinic of Chest and Allergic Diseases, Pediatric Department, Tanta University Hospital. Also it was carried on fifteen apparently healthy children with matched age and sex served as a control group. All studied children were subjected to full history taking, thorough clinical exam-ination, plain chest X-ray, pulmonary function tests (FEV 1and PEFR) by spirometer before and after exercise challenge test, eosinophilic count, serum Lipoxin A4 by ELISA before and immediately after exercise challenge test. Data was analyzed by using SPSS.Results: There was significant more decrease in serum Lipoxin A4 after exercise in asthmatic children with exercise induced bronchoconstriction as compared to asthmatic children without exercise induced bronchoconstriction. Regarding pulmonary function tests (FEV 1 and PEFR), there was signif-icant more decrease in FEV 1 after exercise in asthmatic children with exercise induced bronchoconstriction as com-pared to asthmatic children without exercise induced bron-choconstriction but, there was no significant difference between the asthmatic children with exercise induced bronchoconstric-tion and asthmatic children without exercise induced bron-choconstriction regarding the decrease in PEFR after exercise. And there was no statistical significant difference between subject's sex, age, residence nor BMI.Conclusion: There was inverse correlation between serum LXA4 levels and a reduction in FEV 1 after exercise in asth-matic children. The demonstration of lower levels of lipoxin A4 in association with exercise induced bronchoconstriction suggest that the development of exercise-induced bronchoc-onstriction in asthmatic children may be due to reduced endogenous lipoxin biosynthetic capability. This association not affected by ages and sex of patients.

Efficacy and Safety of Omalizumab (Xolair) for Cholinergic Urticaria in Patients Unresponsive to a Double Dose of Antihistamines: A Randomized Mixed Double-Blind and Open-Label Placebo-Controlled Clinical Trial

Cholinergic urticaria (UCOL) is a highly disabling inducible urticaria triggered by an increase in core body temperature. To explore the safety and efficacy of omalizumab in controlling UCOL. We conducted a multicenter randomized mixed double-blind and open-label (first 4 months blinded followed by 8 months open-label) placebo-controlled clinical trial in 22 patients suffering from UCOL who were unresponsive to a double dose of antihistamines. We performed an exercise challenge test during each visit as our main outcome variable. The overall rate of exercise challenge test negative at week 48 was 31.3%, with an average increase in exercise challenge test negative rate of 2.9% points (95% CI, 1.5-4.2) per visit. Statistically significant differences in the negative exercise challenge test rate between the placebo and active intervention groups were not observed during the blinded period (first 4 months of the study). However, from the fourth dose, a progressive improvement was observed. When comparing before and after treatment, statistically significant improvements in all secondary outcome measures were noted after 4 doses (UCOL score: P= .0015; visual analog scale score: P= .0108; days with symptoms: P= .0125) and after 8 doses (UCOL score: P= .0005; chronic urticaria quality of life questionnaire: P= .0105; visual analog scale score: P= .0008; and days with symptoms: P= .0144). In the follow-up visit after the cessation of treatment, the symptoms reappeared, with positive exercise challenge test result and significant increases in all variables. Only 4 of 22 patients remained asymptomatic after 3 months of no treatment. No adverse effects were reported. This randomized mixed double-blind and open-label placebo-controlled trial showed evidence of the safety and potential efficacy of omalizumab in patients with UCOL.

Prevalence of Exercise Induced Bronchoconstriction in Recreational Adult Hockey Players as determined by Sport Specific Field Exercise Challenge Test

BACKGROUND: Exercise induced bronchoconstriction (EIB) is provoked by exercise and results in narrowing of the airways. Studies have shown an EIB prevalence of 11-50% in athletic populations. The diagnosis of EIB is dependent upon objective measurement of respiratory function, as respiratory symptoms are unreliable. Cold and dry ambient conditions contribute to the severity of EIB. The environmental conditions and manner of exertion an athlete is exposed to in ice hockey are significantly different than any current standardized laboratory test to evaluate for EIB. In a prior study of elite women hockey players, 39.5% presented symptoms of asthma and 21% demonstrated EIB. Sport-specific field exercise challenge tests (SSFECT) have been validated for the assessment of EIB, and are more sensitive than laboratory challenges in elite winter athletes. PURPOSE: To use a SSFECT to determine the prevalence of EIB in adult recreational ice hockey players, and the correlation between reported symptoms and diagnosis by this method. METHODS: Participants were 18 males and 2 females (mean age of 34.7 yrs, mean height of 1.78 m); who participated in 1 of 2 recreational ice hockey leagues in Chicago, IL. Using a Piko-1 portable spirometer, FEV1 was measured prior to the hockey game and immediately following periods 1, 2, and 3. All respiratory measurements occurred with hockey equipment adorned. Airway response was expressed as the percent fall in FEV1 from the baseline value. Diagnosis of EIB was given if athletes had a greater than 10% decrease in FEV1 from baseline measured at any time point. Athletes also completed an intake questionnaire prior to testing which included clinical symptoms, exercise history, and past medical history. RESULTS: EIB was diagnosed in 3/20(15%) athletes. A prior diagnosis of asthma or exercise induced asthma was reported in 5/20 (25%) athletes, yet only one of these had a decrease of > 10 % of FEV1 as measured by this test. Of the three EIB+, two were symptomatic (67%); and of the EIB-, 9/17 (53%) reported respiratory symptoms. Diagnosis of EIB was consistent for all three periods in all but one athlete. Mean FEV1 for the three periods was 4.08, 4.07, and 4.07 respectively. CONCLUSIONS: Symptoms remain unreliable for diagnosis of EIB. SSFECT can be utilized for diagnosis of EIB in ice hockey athletes.

The association between endotoxin in house dust with atopy and exercise-induced bronchospasm in children with asthma

BackgroundStudies have reported protective and adverse associations between microbial exposure and childhood asthma. However, among children with asthma the relationships between endotoxin and exercise-induced bronchospasm (EIB) is less clear. ObjectiveWe investigated the association between exposure to endotoxin in house dust with atopy and EIB in children with asthma. MethodsA cross-sectional survey was conducted among schoolchildren (aged 7–17 years) in the province of Saskatchewan, Canada. A subpopulation with asthma (n = 116) were identified from 335 participants using a validated asthma algorithm. We determined atopy among the asthma subpopulation by skin prick testing (SPT) while EIB was evaluated using exercise challenge testing (ECT). Dust samples were collected from mattress and play area floors, and endotoxin was measured in dust extracts. Logistic regression analyses were used to explore associations between endotoxin with atopy and EIB. ResultsAmong the 116 children with asthma, 99 completed SPT and all had completed ECT. Of these, 71/99 (71.7%) were atopic and 26/116 (22.4%) had EIB. Exposure to high play area endotoxin concentration [adjusted odds ratio (aOR) = 0.15, 95% CI: 0.03–0.85] and load (aOR = 0.11, 95% CI: 0.02–0.73) were negatively associated with atopy. In contrast, EIB was positively associated with high mattress endotoxin concentration (aOR = 6.01, 95% CI: 1.20–30.13). ConclusionIndoor microbial endotoxin exposure has varied associations with atopy and exercise-induced bronchospasm among children with asthma.

Cough reflex sensitivity after exercise challenge testing in children with asthma

Bronchial challenge tests are commonly used in clinical medicine and research. The aim of this study was to clarify changes of cough reflex sensitivity before and after exercise challenge testing in asthma children.42 asthmatic children were submitted to cough reflex sensitivity measurement – capsaicin aerosol in doubling concentrations (from 0.61 to 1250 micromol/l) was inhaled by a single breath method – before and after exercise challenge testing. Concentrations of capsaicin causing two (C2) and five coughs (C5) were reported. Children' (31 boys and 11 girls, mean age 14.05 ± 2.08 yrs) cough reflex sensitivity (median, with the 95% CI) for C2 was before exercise challenge testing 9.77 (6.10–10.99) micromol/l vs. children' C2 after it 7.32 (6.10–14.65) (P = 0.58 for the Wilcoxon two sample paired test). Children' C5 was before exercise challenge testing 19.53 (14.65–80.57) micromol/l vs. C5 after it 39.06 (24.42–58.59) micromol/l (P = 0.09 for the Wilcoxon two sample paired test).We conclude that cough reflex sensitivity was not significantly changed after exercise challenge testing in children with asthma.

Abnormal lung function at preschool age asthma in adolescence?

BackgroundAsthma often begins early in childhood. However, the risk for persistence is challenging to evaluate. ObjectiveThis longitudinal study relates lung function assessed with impulse oscillometry (IOS) in preschool children to asthma in adolescence. MethodsLung function was measured with IOS in 255 children with asthma-like symptoms aged 4–7 years. Baseline measurements were followed by exercise challenge and bronchodilation tests. At age 12–16 years, 121 children participated in the follow-up visit, when lung function was assessed with spirometry, followed by a bronchodilation test. Asthma symptoms and medication were recorded by a questionnaire and atopy defined by skin prick tests. ResultsAbnormal baseline values in preschool IOS were significantly associated with low lung function, the need for asthma medication, and asthma symptoms in adolescence. Preschool abnormal R5 at baseline (z-score ≥1.645 SD) showed 9.2 odds ratio (95%CI 2.7;31.7) for abnormal FEV1/FVC, use of asthma medication in adolescence, and 9.9 odds ratio (95%CI 2.9;34.4) for asthma symptoms. Positive exercise challenge and modified asthma-predictive index at preschool age predicted asthma symptoms and the need for asthma medication, but not abnormal lung function at teenage. ConclusionAbnormal preschool IOS is associated with asthma and poor lung function in adolescence and might be utilised for identification of asthma persistence.

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

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

The Diagnostic Value of Impulse Oscillometry and Plethysmography for the Assessment of Exercise-Induced Bronchoconstriction in Asthmatic Children

Exercise-induced bronchoconstriction (EIB) is a key clinical problem for asthmatic children. Exercise challenge tests, used to confirm EIB, are time consuming and require patient cooperation. The a...