Asthma in every fifth child in Oslo, Norway: a 10-year follow up of a birth cohort study

Systemic IL-26 correlates with improved asthma control in children sensitized to dog allergen

BACKGROUND

Interleukin (IL)-26 is produced by T helper type 17 (Type 17) cells and exerts immunomodulatory plus antimicrobial effects. Previous studies show that local IL-26 concentrations in the airways are higher in patients with uncontrolled than in those with controlled asthma, and that this intriguing cytokine bears biomarker potential. Here, we determined how systemic IL-26 relates to allergen sensitization, asthma severity, and to IL-17 A in children.

METHODS

Serum samples were obtained from children with (n = 60) and without (n = 17) sensitization to dog allergen, and IL-26 and IL-17 A protein concentrations were measured using ELISA. Self-reported history, including medication use and validated symptom-based questionnaire scores, was recorded.

RESULTS

The serum concentrations of IL-26 were enhanced in allergen-sensitized subjects and correlated with those of IL-17 A in a positive manner. However, the IL-26 concentrations did not markedly differ between allergen-sensitized subjects with and without asthma, eczema, allergic rhinitis, or a history of food allergy. Notably, IL-26 concentrations correlated with increasing Asthma Control Test (ACT) scores in a positive manner and with inhaled corticosteroid in a negative manner, amongst sensitized subjects with asthma. Moreover, subjects with asthma requiring ≥ 1 course of oral corticosteroids in the preceding 12 months had decreased IL-26 concentrations.

CONCLUSION

This study forwards evidence that systemic IL-26, just like IL-17 A, is involved in allergen sensitization among children. The association of systemic IL-26 with improved asthma control is compatible with the cellular sources being recruited into the airways in severe asthma, which supports that this kinocidin bears potential as a biomarker and therapeutic target.

Exercise-induced bronchoconstriction, allergy and sports in children

Exercise-induced bronchoconstriction (EIB) is characterized by the narrowing of airways during or after physical activity, leading to symptoms such as wheezing, coughing, and shortness of breath. Distinguishing between EIB and exercise-induced asthma (EIA) is essential, given their divergent therapeutic and prognostic considerations. EIB has been increasingly recognized as a significant concern in pediatric athletes. Moreover, studies indicate a noteworthy prevalence of EIB in children with atopic predispositions, unveiling a potential link between allergic sensitivities and exercise-induced respiratory symptoms, underpinned by an inflammatory reaction caused by mechanical, environmental, and genetic factors. Holistic management of EIB in children necessitates a correct diagnosis and a combination of pharmacological and non-pharmacological interventions. This review delves into the latest evidence concerning EIB in the pediatric population, exploring its associations with atopy and sports, and emphasizing the appropriate diagnostic and therapeutic approaches by highlighting various clinical scenarios.

Respiratory oscillometry testing in relation to exercise in healthy and asthmatic Thoroughbreds

BACKGROUND

Racehorses may experience exercise-induced bronchodilation or bronchoconstriction, with potential differences between healthy and asthmatic individuals.

OBJECTIVES

To identify exercise-related lung function variations by oscillometry in racehorses, compare lung function between healthy and mild equine asthma (MEA) horses, assess oscillometry's potential as a predictor of racing fitness.

STUDY DESIGN

Prospective case-control clinical study.

METHODS

Fourteen Thoroughbred racehorses (5 healthy, 9 MEA) underwent a protocol including respiratory oscillometry at rest, exercise with fitness monitoring, oscillometry at 15 and 45 min post-exercise, and bronchoalveolar lavage fluid (BALf) cytology. Oscillometry parameters (resistance [Rrs] and reactance [Xrs]) were compared within and between healthy and MEA groups at different timepoints. Associations between Rrs and Xrs at rest and 15 min post-exercise and BALf cytology and fitness indices were evaluated.

RESULTS

MEA horses showed higher Rrs at 15 min post-exercise (0.6 ± 0.2 cmH2 O/L/s) than healthy horses (0.3 ± 0.1 cmH2 O/L/s) (p < 0.01). In healthy horses, Rrs decreased at 15 min post-exercise compared with resting values (0.5 ± 0.1 cmH2 O/L/s) (p = 0.04). In MEA horses, oscillometry parameters did not vary with time. Post-exercise Xrs inversely correlated with total haemosiderin score (p < 0.01, r2  = 0.51). Resting Rrs inversely correlated with speed at 200 bpm (p = 0.03, r2  = -0.61), and Xrs with maximum heart rate (HR) during exercise (p = 0.02, r2  = -0.62). Post-exercise Rrs inversely correlated with mean (p = 0.04, r2  = -0.60) and maximum speed (p = 0.04, r2  = -0.60), and HR variability (p < 0.01, r2  = -0.74).

MAIN LIMITATIONS

Small sample size, oscillometry repeatability not assessed, potential interference of upper airway obstructions, external variables influencing fitness indices.

CONCLUSIONS

Oscillometry identified lung function differences between healthy and MEA horses at 15 min post-exercise. Only healthy horses exhibited exercise-induced bronchodilation. Oscillometry showed potential in predicting subclinical airway obstruction.

Multimorbidity and acute infectious diseases in urban and semi-urban settings in Peru: A mixed-methods study

Background

The co-occurrence of chronic diseases and acute infectious events exacerbates disability and diminishes quality of life, yet research in Low- and Middle-Income countries is scarce. We aimed to investigate the relationship between infectious events and multimorbidity in resource-constrained settings.

Methods

We conducted a sequential mixed-method study in Lima and Tumbes, Peru, with participants having multimorbidity from the CRONICAS Cohort Study. They completed a questionnaire on the occurrence, treatment, and health-seeking behaviour related to acute infectious events. Qualitative interviews explored the perceptions and links between multimorbidity and acute infectious events for a subgroup of participants.

Findings

Among individuals with multimorbidity, low awareness of chronic conditions and poor medication adherence. The cumulative incidence for respiratory and gastrointestinal infections, the most reported acute conditions, was 2.0 [95%CI: 1.8-2.2] and 1.6 [1.2-1.9] events per person per year, respectively. Individuals with cancer (6.4 [1.6-11.2] events per person per year) or gastrointestinal reflux (7.2 [4.4-10.1] events per person per year) reported higher cumulative incidence of infectious events than others, such as those with cardiovascular and metabolic conditions (5.2 [4.6-5.8] events per person per year). Those with three or more chronic conditions had a slightly higher cumulative incidence compared with individuals with two conditions (5.7 [4.4-7.0] vs 5.0 [4.4-5.6] events per person per year). Around 40% of individuals with multimorbidity sought healthcare assistance, while others chose drugstores or didn't seek help. Our qualitative analysis showed diverse perceptions among participants regarding the connections between chronic and acute conditions. Those who recognized a connection emphasized the challenges in managing these interactions.

Interpretation

Our study advances understanding of multimorbidity challenges in resource-limited settings, highlighting the impact of acute infections on patients' existing multimorbidity burden.

A Meta Analysis of Physical Exercise on Improving Lung Function and Quality of Life Among Asthma Patients

Objective

This paper aims to perform a systematic assessment of the influence of physical exercise on asthma patients and discuss the intervention effects of different exercises on the lung function FEV1 (%pred) and quality of life among asthma patients so as to lay a scientific foundation for improving asthma symptoms.

Methods

Both Chinese and English databases were retrieved, including PubMed, Web of Science, Embase, The Cochrane Library, CBM, CNKI, Wan Fang Data, and VIP, whose retrieval period started from the founding date of each database to 1st, November 2021. Randomized controlled trials (RCT) studying the symptom indicators of asthma patients were collected. Those collected papers were screened according to the Inclusion Criteria and Exclusion Criteria. Then, methodological quality assessments were conducted on the included papers, and combined effect sizes were analyzed by using software ReMan 5.3.5.

Results

The meta analysis showed that physical exercise could significantly improve lung function FEV1 (%pred) and quality of life score. Trails containing breathing exercise are the main source of heterogeneity, and the subgroup of breathing exercise may have better performance than the subgroup of aerobic exercise in improving FEV1 (%pred).

Conclusion

Physical exercise can significantly improve the symptoms and quality of life of asthma patients. Except the breathing exercise that showed heterogeneity, the subgroup of aerobic exercise could improve the capacity of FEV1 (%pred) more effectively, which led to a significant difference in the influence of quality of life. However, with regard to the gymnastic exercise including breathing exercise, there are limited same intervention methods and insufficient same outcome indicators. Therefore, more precise and high-quality researches are needed to make deeper verification in the future.

Allergic sensitization to lipocalins reflects asthma morbidity in dog dander sensitized children

Background

Sensitization to dog is an important risk factor for asthma in children, but the clinical relevance of IgE to available dog‐ and furry animal allergen molecules is uncertain.

Methods

Spirometry, methacholine challenge, fraction of exhaled nitric oxide, nasal challenge with dog extract and questionnaires were performed in 59 dog‐sensitized children (age 10–18 years). Serum IgE to dog‐, cat‐, horse extracts and the allergen molecules Can f 1–6, Fel d 1, Fel d 2, Fel d 4 and Equ c 1 were evaluated.

Results

Median numbers of positive IgE results to furry animal allergen molecules among children without asthma was 3, with asthma 5.5 and with troublesome asthma 9 (asthma vs. no asthma; p = 0.039; troublesome asthma vs. no asthma; p = 0.009). The odds ratio for asthma if sensitized to any lipocalin was 7.2 (95% confidence Interval: 1.44–35.9). Children with troublesome asthma had higher IgE levels to the lipocalins Can f 2, Can f 4 and Can f 6 compared to the rest of the study population (44 vs. 4.1 kU_A/L, p = 0.015; 5.8 vs. 0.9 kU_A/L, p = 0.018 and 1.3 vs. 0.7 kU_A/L, p = 0.03 respectively). Furthermore, a positive nasal challenge was more common among children with troublesome asthma (83% vs. 36%, p = 0.036).

Conclusions

Polysensitization to furry animal allergens and lipocalins is associated with asthma in dog‐sensitized children. Children with troublesome asthma have higher IgE levels to several dog lipocalins than other dog sensitized children.

Key message

Polysensitization to furry animal allergens and high IgE levels to the dog lipocalins Can f 2, Can f 4 and Can f 6 is associated with asthma severity in dog dander sensitized children. Molecular allergy diagnostics may thus help the clinicians to evaluate the impact of allergic sensitization on asthma morbidity.

Evaluating Children and Adolescents with Suspected Exercise Induced Asthma: Real Life Data

OBJECTIVE

Exercise-induced bronchoconstriction (EIB) occurs frequently in children and adolescents and may be a sign of insufficient asthma control. EIB is often evaluated by respiratory symptoms, spirometry, eNO measurement and methacholine testing (MCT) instead of time consuming exercise test. Aim of this study was to analyse the amount of patients for which an exercise challenge in a cold chamber (ECC) was needed for a clear EIB diagnosis, to characterize EIB phenotypes and the incidence of exercise induced laryngeal obstruction (EILO) in a large cohort of patients with EIB.

METHODS

A retrospective analysis was performed in 595 children and adolescents (mean age 12.1 years) with suspected EIB from January 2014 to December 2018. Complete data sets of skin prick test, spirometry, eNO and MCT were available from 336 patients.

RESULTS

An ECC to confirm the EIB diagnosis was performed in 125 (37.2%) of patients. Three EIB phenotypes were detected: group 1: EIB without allergic sensitization (n=159); group 2: EIB with other than house dust mite (HDM) sensitization (n=87) and group 3: EIB with HDM sensitization (n=90). MCT and eNO showed significant differences between the subgroups: An eNO>46 ppb and/or a MCT<0.1 mg was found in 23.9% vs. 50.6% vs. 57.8% in group 1-3, respectively. Significantly more patients suffered from EILO in group 1 compared to group 2 and 3 (n=13 vs. n=1).

CONCLUSION

EIB without sensitization is as often as EIB with sensitization. In patients without sensitization, EILO has to be considered as a possible cause of symptoms during exercise.

Allergy-related diseases in childhood and risk for abdominal pain-related functional gastrointestinal disorders at 16 years-a birth cohort study

BACKGROUND

Studies on allergy-related diseases in relation to abdominal pain-related functional gastrointestinal disorders (AP-FGIDs) in children are few and results are contradictory. We examined the associations between childhood allergy-related diseases and adolescent AP-FGIDs in general and irritable bowel syndrome (IBS) in particular.

METHOD

Prospective population-based birth cohort study of 4089 children born in Sweden 1994-1996. We analysed data from 2949 children with complete follow-up at 16 years (y) and no diagnosis of inflammatory bowel disease or coeliac disease at 12y or 16y. Asthma, rhinitis, eczema, and food hypersensitivity (FH) were assessed through questionnaires at 1-2y, 4y, 8y, 12y, and 16y. AP-FGIDs and IBS were assessed through questionnaires at 16y and defined according to the Rome III criteria. Associations between childhood allergy-related diseases and any AP-FGID and IBS and 16y respectively were examined using binomial generalized linear models with a log link function and described as relative risk with 95% confidence intervals.

RESULTS

The prevalence of any AP-FGID and IBS at 16y were 12.0% and 6.0% respectively. Eczema at 1-2y, 4y, and 8y, and FH at 12y and 16y were associated with an increased risk for any AP-FGID at 16y. Asthma and FH at 12y and 16y were associated with an increased risk for IBS at 16y. The relative risk for IBS at 16y increased with increasing number of concurrent allergy-related diseases at 16y, but linear trend for relative risk was only borderline statistically significant (P for trend = 0.05).

CONCLUSIONS

This prospective population-based study demonstrated positive associations between childhood allergy-related diseases and adolescent AP-FGIDs, including IBS, implicating shared pathophysiology among these disorders.

Management of Intermittent and Persistent Asthma in Adolescent and High School Athletes

Asthma is the most common chronic condition during childhood and adolescence, affecting an estimated 8% of children and youngsters below 18 years in the United States and the United Kingdom. In adolescent athletes, asthma-like symptoms may represent a common consequence of regular sport practice. Asthma in young athletes poses several challenges, including the ambiguity of definitions and diagnosis of asthma resulting from exercise-induced symptoms, the best pharmacological treatments, and the nonpharmacological options for the management of disease and the challenges inherent to this age group. At a time when the regular practice of sports is increasingly being recommended for a healthy living, the support network around the young athletes is crucial to reduce the impact of asthma on their physical and emotional well-being. In this review, we examine the main issues around the definitions and clinical differentiations of asthma in young sport athletes. We discuss best practice approaches to improve the adherence to the clinical management, including nonpharmacological strategies directed at the family and trainers of athlete adolescents.

Nasal upregulation of CST1 in dog-sensitised children with severe allergic airway disease

Background

The clinical presentation of children sensitised to dog dander varies from asymptomatic to severe allergic airway disease, but the genetic mechanisms underlying these differences are not clear. The objective of the present study was to investigate nasal transcriptomic profiles associated with dog dander sensitisation in school children and to reveal clinical symptoms related with these profiles.

Methods

RNA was extracted from nasal epithelial cell brushings of children sensitised to dog dander and healthy controls. Blood sample analyses included IgE against dog dander, dog allergen molecules, other airborne and food allergens, basophil activation and white blood cell counts. Clinical history of asthma and rhinitis was recorded, and lung function was assessed (spirometry, methacholine provocation and exhaled nitric oxide fraction).

Results

The most overexpressed gene in children sensitised to dog dander compared to healthy controls was CST1, coding for Cystatin 1. A cluster of these children with enhanced CST1 expression showed lower forced expiratory volume in 1 s, increased bronchial hyperreactivity, pronounced eosinophilia and higher basophil allergen threshold sensitivity compared with other children sensitised to dog dander. In addition, multi-sensitisation to lipocalins was more common in this group.

Conclusions

Overexpression of CST1 is associated with more severe allergic airway disease in children sensitised to dog dander. CST1 is thus a possible biomarker of the severity of allergic airway disease and a possible therapeutic target for the future treatment of airborne allergy.

Association of early life and acute pollen exposure with lung function and exhaled nitric oxide (FeNO). A prospective study up to adolescence in the GINIplus and LISA cohort

BACKGROUND

Pollen exposure has both acute and chronic detrimental effects on allergic asthma, but little is known about its wider effects on respiratory health. This is increasingly important knowledge as ambient pollen levels are changing with the changing global climate.

OBJECTIVE

To assess associations of pollen exposure with lung function and fractional exhaled nitric oxide (FeNO) at age 15 in two prospective German birth cohorts, GINIplus and LISA.

METHODS

Background city-specific pollen exposure was measured in infancy (during the first three months of life), and contemporary (on the day of and 7 days prior to lung function measurement). Greenness levels within circular buffers (100-3000 m) around the birth and 15-year home addresses were calculated using the satellite-derived Normalized Difference Vegetation Index. Regression models were used to assess the associations of grass and birch pollen with lung function and FeNO, and the modifying effects of residential greenness were explored.

RESULTS

Cumulative early life exposure to grass pollen was associated with reduced lung function in adolescence (FEV₁: -4.9 mL 95%CI: -9.2, -0.6 and FVC: -5.2 mL 95%CI: -9.8, -0.5 per doubling of pollen count). Acute grass pollen exposure was associated with increased airway inflammation in all children, with higher FeNO increases in children living in green areas. In contrast acute birch pollen exposure was associated with reduced lung function only in children sensitised to birch allergens.

CONCLUSION

This study provides suggestive evidence that early pollen exposure has a negative effect on later lung function, which is in turn influenced by acute pollen exposures.

A systematic review of asthma case definitions in 67 birth cohort studies

BACKGROUND

Birth cohort studies are a valuable source of information about potential risk factors for childhood asthma. To better understand similarities and variations in findings between birth cohort studies, the methodologies used to measure asthma require consideration.

OBJECTIVE

To review and appraise the definitions of "asthma" used in birth cohort studies.

METHODS

A literature search, conducted in December 2017 in the MEDLINE database and birth cohort repositories, identified 1721 citations published since 1990. Information extracted included: study name, year of publication, sample size, sample age, prevalence of asthma (%), study region, source of information about asthma, measured outcome, and asthma case definition. A meta-analysis evaluated whether asthma prevalence in cohorts from Europe and North America varied by the studies' definition of asthma and by their data sources.

RESULTS

The final review included 67 birth cohorts, of which 48 (72%) were from Europe, 14 (21%) from North America, 3 (5%) from Oceania, 1 (1%) from Asia and 1 (1%) from South America. We identified three measured outcomes: "asthma ever", "current asthma", and "asthma" without further specification. Definitions of "asthma ever" were primarily based upon an affirmative parental response to the question whether the child had ever been diagnosed with asthma by a physician. The most frequently used definition of "current asthma" was "asthma ever" and either asthma symptoms or asthma medications in the last 12 months. This definition of "current asthma" was used in 16 cohorts. There was no statistically significant difference in the pooled asthma prevalence in European and North American cohorts that used questionnaire alone versus other data sources to classify asthma.

CONCLUSION

There is substantial heterogeneity in childhood asthma definitions in birth cohort studies. Standardisation of asthma case definitions will improve the comparability and utility of future cohort studies and enable meta-analyses.

Parameters of cardiac symptoms in young athletes using the Heartbytes database

Introduction: To determine clinical parameters that are related to abnormal cardiac symptoms in physically active youth. Methods: We used Simon's Heart Heartbytes National Youth Cardiac Registry to collect data from adolescent athletes in southeastern Pennsylvania. We collected age, race/ethnicity, abnormal cardiac symptoms, medical history, medication use, caffeine intake, and family history. We obtained height, weight, blood pressure, cardiac murmur findings, and ECGs. Echocardiogram was obtained if necessary. Binary logistic regression analysis was performed to identify independent associations between abnormal cardiac symptoms and collected variables. The odds ratio (OR), 95% confidence interval (95% CI), and p-values were used as statistical values. Results: Of the 887 athletes (543 males and 344 females, age = 16.9 ± 2.1 years, height = 166.9 ± 11.4 cm, weight = 62.0 ± 16.0 kg), 186 (21%) had abnormal cardiac symptoms including chest pain, passing out, difficulty breathing, extreme fatigue, and heart race. There was an independent association between abnormal symptoms and a past medical history (OR: 4.77, 95%CI: 3.18, 7.17, p = 0.001) and medication use (OR: 1.74, 95%CI: 1.08, 2.79, p = 0.022). In medical history, young athletes with asthma showed a greater propensity of abnormal cardiac symptoms (48.9%) compared to young athletes without (14.0%, p = 0.001). Additionally, young athletes with anxiety or depression demonstrated a higher proportion of abnormal cardiac symptoms (48.9%) than those without (19.5%, p = 0.001). Although the association between the presence of abnormal symptoms and African-American race (OR: 2.04, 95%CI: 0.96, 4.35, p = 0.065) and average daily consumption of at least 2 caffeine drinks (OR: 2.08, 95%CI: 0.86, 5.02, p = 0.103) were not significant, there was a trend to reach the a priori significance level. Conclusions: This study identified several clinical parameters that are associated with symptoms suggestive of abnormal cardiac conditions. Larger studies need to be done to better sort out the clinical history that may contribute to false positives to further reduce false positives at heart screenings.

Air pollution during infancy and lung function development into adolescence: The GINIplus/LISA birth cohorts study

BACKGROUND

Limited evidence exists on how air pollution exposure during infancy, i.e. the first year of life, may affect lung function development into adolescence.

OBJECTIVES

To investigate the association between exposure to air pollution during the first-year of life and lung function development up to the age of 15 in Germany.

METHODS

We investigated 915 children from the GINIplus and LISA birth cohorts from Munich (n = 181) and Wesel (n = 734), who had at least two spirometric measurements at ages 6, 10 and 15. Z-scores of forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) were calculated. Annual average concentrations of nitrogen dioxide, particulate matter with diameters <2.5, <10 and 2.5-10 µm (PM_{2.5/10/coarse}), and PM_2.5 absorbance at home addresses during the first-year of life, were estimated by land-use regression models. Associations between infancy exposure and lung function changes were fitted using multivariable linear mixed models with adjustment for potential confounders.

RESULTS

For per interquartile range increase in air pollutants during the first-year life, FEV₁ z-scores declined annually by -0.012 (95% confidence interval (CI): -0.014, -0.009) for PM_2.5 to -0.023 (95%CI: -0.028, -0.018) for PM_coarse. The declines in FVC were lower than FEV₁ [-0.006 (95%CI: -0.008, -0.003) to -0.011 (95%CI: -0.019, -0.003)]. In Munich, the attenuations were only significant for FEV₁. Effect estimates of infancy exposure for certain air pollutants were higher for groups with asthma, older maternal age, and breastfeeding <12 weeks than their counterparts.

DISCUSSION

Infancy exposure to higher air pollution may reduce lung function development up to adolescence, with airway size more affected than lung volume restriction. The potential modifying effects of maternal age, asthmatic status of children and breastfeeding warrant further exploration.

Associations of dog and cat ownership with wheezing and asthma in children: Pilot study of the Japan Environment and children's study

Objectives

No previous study has used repeated measures data to examine the associations of dog/cat ownership with wheezing and asthma prevalence among children. This prospective study used repeated measurers analysis to determine whether dog/cat ownership in childhood is an independent risk factor for wheezing and asthma, after adjustment for gestational, socio-economical, and demographical confounders confounders, in Japan.

Methods

We conducted a multicenter pilot study of the Japan Environment and Children's Study (JECS) during 2009–2010. Among 440 newborn infants enrolled, 410 (52.8% males) were evaluated for dog/cat ownership in the home and history of wheezing and asthma in five follow-up questionnaire surveys (until age 6 years). Dog/cat ownership during follow-up period was categorized into four groups: 7.6% were long-term dog/cat owners, 5.9% were toddler-age owners, 5.9% were preschool-age owners, and 80.7% were never owners.

Results

The prevalence of wheezing during follow-up period increased from 20.8% to 35.4% and the prevalence of asthma increased from 1.3% to 16.3%. A fitted logistic generalized estimating equation models including important confounders showed no significant associations of the interaction between dog and/or cat ownership and follow-up time with the risks of wheezing and asthma. However, the risks of wheezing and asthma were slightly lower for long-term and toddler-age dog/cat owners than for preschool-age and never owners.

Conclusions

The present findings suggest that dog and cat ownership from toddler-age does not increase the risks of wheezing and asthma compared with never owners among Japanese children.

Clinical recommendations for cardiopulmonary exercise testing in children with respiratory diseases

INTRODUCTION

Cardiopulmonary exercise testing (CPET) quantitates and qualitates the integrated physiological response of a person to incremental exercise and provides additional information compared to static lung function tests alone.

AREAS COVERED

This review covers rationale for the use of CPET parameters beyond the usual parameters like peak oxygen uptake and peak minute ventilation in children with respiratory disease.

EXPERT OPINION

CPET provides a wealth of data from rest, submaximal and maximal exercise and data during recovery from exercise. In this review, an interpretative approach is described for analyzing CPET data in children with respiratory disease.

Ambient Air Pollution and Variation in Multiple Domains of Asthma Morbidity among Peruvian Children

RATIONALE

A large portion of asthma morbidity occurs in low- and middle-income countries, and Peru suffers particularly high asthma prevalence. Ambient air exposures are also high, and likely play a role. Most studies of environmental exposures focus on understanding contributors to health care utilization or mortality risk; however, less severe outcomes may still impact quality of life (QOL).

OBJECTIVES

To study the association between multiple pollutants and several asthma domains in Peruvian children.

METHODS

A total of 484 children aged 9-19 years with asthma were followed for 6-9 months, and evaluated for asthma control, asthma-related QOL, missed school days, and health care utilization. We used geographically distributed monitors to estimate air pollutant concentrations and multivariable generalized linear mixed models to model asthma outcomes as a function of pollutants.

RESULTS

A total of 67% of children had moderate to severe persistent asthma. In multipollutant models, higher particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5), black carbon, and nitrogen dioxide concentrations were independently associated with worse asthma control. For each interquartile range increase in PM_2.5 or nitrogen dioxide concentration, there was a 59% or 34% higher odds of uncontrolled asthma, respectively. If the proportion of PM_2.5 that was black carbon increased, there were increased odds of uncontrolled asthma. Similarly, pollutants were independently associated with worse asthma-related QOL, and PM exposure was associated with increased risk of health care utilization.

CONCLUSIONS

Our study highlights the importance of pollutant exposures on multiple domains of asthma morbidity among Peruvian children, including not only acute exacerbations, but also on general asthma burden, such as worse asthma symptom control and QOL.

Perfluoroalkyl substances, airways infections, allergy and asthma related health outcomes - implications of gender, exposure period and study design

INTRODUCTION

Exposure to perfluoroalkyl substances (PFASs) has been inconsistently associated with asthma, allergic diseases and airways infections in early childhood. The aim of the study was, therefore, to investigate the effect of childhood exposure to PFASs on asthma and allergy related outcomes and on airways infections before and during puberty using the prospective birth cohort Environment and Childhood Asthma (ECA) Study. Aspects of gender, exposure period and study design (cross-sectional and longitudinal) were also taken into consideration.

MATERIAL AND METHODS

Included in the study was 378 participants with PFAS measurements at age 10 years and follow-up data at ages 10 years (cross sectional data) and 16 years (longitudinal data). Eight PFASs with at least 70% of measurements above the limit of quantification (LOQ) in the child's serum were included in the present study: perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluourononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUnDA), perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS) and perfluorooctane sulfonate (PFOS). The PFAS levels were converted into interquartile range (IQR). In addition, perfluorooctane sulfonamide (PFOSA) detected in 60% of the samples, was recoded into "not detected /detected". Binomial, multinomial and linear regression were used, followed by Bonferroni adjustment to correct for multiple comparisons. Sensitivity analyses evaluating the effect of extreme PFAS values and gender were performed.

RESULTS

In the cross sectional data at 10 years a positive statistically significant association was seen between PFHpA and asthma in girls. In the longitudinal data, PFNA, PFDA and PFUnDA were inversely associated with atopic dermatitis (AD) in girls and with PFHxS in all participants and in boys. Further, PFNA and PFHpS were positively associated with rhinitis in girls and with PFOA in all participants. There seems to be a suggestive pattern of increased risk of allergic sensitisation in all participants and a decreased risk in boys, but due to different results in main and sensitivity analyses these findings should be interpreted with caution. No associations were found between PFASs and lung function. For airways infections and longitudinal data, PFDA was inversely associated with common cold, while positive association was found for PFHpA, PFOA, PFHpS and PFOS and lower respiratory tract infections (LRTI).

DISCUSSION AND CONCLUSION

Our results lend further support for an immunosuppressive effect of PFASs on AD and LRTI. Gender seems to be important for some exposure-health associations. No clear pattern in exposure-health associations was observed with regard to exposure period or study design, with the exception of asthma where significant findings have mostly been reported in cross-sectional studies.

Exhaled TGF-β1 levels before and after an exercise challenge in asthmatic and healthy children, and during exacerbation

BACKGROUND

There is conflicting data regarding the role of transforming growth factor-β1 (TGF-β1) in the pathogenesis of airway hyper-reactivity and asthma exacerbation.

OBJECTIVE

To investigate the role of exhaled-TGF-β1 in exercise-induced bronchospasm (EIB) in asthmatic and nonasthmatic healthy children, and in asthma exacerbation and asthma control.

METHODS

The exhaled-TGF-β1 levels of 56 stable asthmatic children and 15 nonasthmatic healthy children were evaluated before and 30 min after an exercise challenge. The exhaled-TGF-β1 levels of 20 additional children with asthma exacerbation were evaluated.

RESULTS

While no significant difference in the exhaled-TGF-β1 levels was found at the baseline, exhaled-TGF-β1 levels after the exercise challenge were significantly higher in the non-EIB (n = 31) asthmatics when compared to the asthmatic children with EIB (n = 25) (p = 0.04). Although there was a statistically significant increase in the concentration of the exhaled-TGF-β1 after the exercise challenge in the non-EIB asthmatics (p = 0.008), the concentration of the TGF-β1 was not increased after the exercise challenge in EIB + asthmatics. The exhaled-TGF-β1 was significantly correlated with the ACT score (p = 0.01, r = 0.49) and the baseline FEV₁ level (p = 0.02, r = 0.35). The exhaled-TGF-β1 levels were significantly higher in the stable asthmatic children when compared to the nonasthmatic children (p < 0.0001). There was no significant difference in exhaled-TGF-β1 levels after the exercise challenge in the nonasthmatics. The exhaled-TGF-β1 levels were significantly lower in those children with asthma exacerbation when compared to the stable asthmatic children (p = 0.0003).

CONCLUSION

Our results suggest that TGF-β1 may play a role in suppressing airway reactivity and its deficiency is associated with asthma exacerbation.

Multimorbidity at sea level and high-altitude urban and rural settings: The CRONICAS Cohort Study

Objective:

To characterize the prevalence and clustering of multimorbidity in four diverse geographical settings in Peru.

Methods:

Multimorbidity, defined as having ≥2 chronic conditions, was studied in adults aged ≥35 years in four diverse settings in Peru: Lima, Tumbes, and urban and rural Puno. Six of these conditions (alcohol disorder, asthma, chronic obstructive pulmonary disease, depression, diabetes, and hypertension) were cataloged as objectively ascertained chronic conditions and paired in dyads to explore clusters of multimorbidity.

Results:

We analyzed data from 2890 adults, mean age 55.2 years, 49% males. Overall, 19.1% of participants had multimorbidity, ranging from 14.7% in semi-urban Tumbes to 22.8% in Lima. The dyads with the highest coexistence (approximately 20%) were observed in hypertension and diabetes in Tumbes, whereas the dyads with lowest coexistence (approximately 1%) were those involving asthma in all study sites. In terms of clusters, Tumbes showed a predominance of hypertension and diabetes, urban and rural Puno a predominance of depression and alcohol disorders, and Lima a higher degree of coexistence of all of the six conditions than in the other clusters.

Conclusion:

Multimorbidity is common and the pattern of clusters is highly heterogeneous. The conditions to prioritize will vary in each setting.

Shared prenatal impacts among childhood asthma, allergic rhinitis and atopic dermatitis: a population-based study

Background

Increasing prevalence of childhood allergic diseases including asthma is a global health concern, and we aimed to investigate prenatal risk factors for childhood asthma and to address the potential shared prenatal impacts among childhood asthma, allergic rhinitis (AR) and atopic dermatitis (AD).

Methods

We used two claim databases, including Taiwan Birth Cohort Study (TBCS) and National Health Insurance Research Database (NHIRD), to identify independent paired mother–child data (mother–child dyads) between 2006 and 2009. The association between prenatal factors and asthma was determined by calculating adjusted odds ratio (aOR) with 95% confidence interval (CI) using conditional logistic regression analysis.

Results

A total of 628,878 mother–child dyads were included, and 43,915 (6.98%) of children developed asthma prior to age 6. We found that male gender (aOR 1.50, 95% CI 1.47–1.53), maternal asthma (aOR 1.80, 95% CI 1.71–1.89), maternal AR (aOR 1.33, 95% CI 1.30–1.37), preterm birth (aOR 1.32, 95% CI 1.27–1.37), low birth weight (aOR 1.14, 95% CI 1.10–1.19) and cesarean section (aOR 1.10, 95% CI 1.08–1.13) were independent predictors for childhood asthma. A high urbanization level and a low number of older siblings were associated with asthma in a dose–response manner. Notably, we identified that the association between maternal asthma and childhood asthma (aOR 1.80, 95% CI 1.71–1.89) was stronger compared with those between maternal asthma and childhood AR (aOR 1.67, 95% CI 1.50–1.87) as well as childhood AD (aOR 1.31, 95% CI 1.22–1.40). Similarly, the association between maternal AR and childhood AR (aOR 1.62, 95% CI 1.53–1.72) was higher than those between maternal AR and childhood asthma (aOR 1.33, 95% CI 1.30–1.37) as well as childhood AD (aOR 1.35, 95% CI 1.31–1.40). Furthermore, the number of maternal allergic diseases was associated with the three childhood allergic diseases in a dose–response manner.

Conclusions

In conclusion, this population-based study provided evidence of prenatal impacts on childhood asthma and demonstrated the shared maternal impacts among childhood asthma, AR, and AD. These findings highlight the shared prenatal impacts among allergic diseases, and studies are warranted to address the pivotal pathway in allergic diseases.

Predictors and reproducibility of exercise-induced bronchoconstriction in cold air

Background

Physical activity is an important part of life, and hence exercise-induced bronchoconstriction (EIB) can reduce the quality of life. A standardized test is needed to diagnose EIB. The American Thoracic Society (ATS) guidelines recommend an exercise challenge in combination with dry air. We investigated the feasibility of a new, ATS guidelines conform exercise challenge in a cold chamber (ECC) to detect EIB. The aim of this study was to investigate the surrogate marker reaction to methacholine, ECC and exercise challenge in ambient temperature for the prediction of a positive reaction and to re-evaluate the reproducibility of the response to an ECC.

Methods

Seventy-eight subjects aged 6 to 40 years with suspected EIB were recruited for the study. The subjects performed one methacholine challenge, two ECCs, and one exercise challenge at an ambient temperature. To define the sensitivity and specificity of the predictor, a receiver-operating characteristic curve was plotted. The repeatability was evaluated using the method described by Bland and Altman (95% Limits of agreement).

Results

The following cut-off values showed the best combination of sensitivity and specificity: the provocation dose causing a 20% decrease in the forced expiratory volume in 1 s (PD₂₀FEV₁) of methacholine: 1.36 mg (AUC 0.69, p < 0.05), the maximal decrease in FEV₁ during the ECC: 8.5% (AUC 0.78, p < 0.001) and exercise challenges at ambient temperatures: FEV₁ 5.2% (AUC 0.64, p = 0.13). The median decline in FEV₁ was 14.5% (0.0–64.2) during the first ECC and 10.7% (0.0–52.5) during the second ECC. In the comparison of both ECCs, the Spearman rank correlation of the FEV₁ decrease was r = 0.58 (p < 0.001). The 95% limits of agreement (95% LOAs) for the FEV₁ decrease were − 17.7 to 26.4%.

Conclusions

The surrogate markers PD₂₀FEV₁ of methacholine and maximal decrease in FEV₁ during ECC can predict a positive reaction in another ECC, whereas the maximal FEV₁ decrease in an exercise challenge at an ambient temperature was not predictive. Compared with previous studies, we can achieve a similar reproducibility with an ECC.

Clinical trial registration

NCT02026492 (retrospectively registered 03/Jan/2014).

A review on the pathophysiology of asthma remission

Asthma is a chronic respiratory condition, which is highly prevalent worldwide. Although no cure is currently available, it is well recognized that some asthma patients can spontaneously enter remission of the disease later in life. Asthma remission is characterized by absence of symptoms and lack of asthma-medication use. Subjects in asthma remission can be divided into two groups: those in clinical remission and those in complete remission. In clinical asthma remission, subjects still have a degree of lung functional impairment or bronchial hyperresponsiveness, while in complete asthma remission, these features are no longer present. Over longer periods, the latter group is less likely to relapse. This remission group is of great scientific interest due to the higher potential to find biomarkers or biological pathways that elicit or are associated with asthma remission. Despite the fact that the definition of asthma remission varies between studies, some factors are reproducibly observed to be associated with remitted asthma. Among these are lower levels of inflammatory markers, which are lowest in complete remission. Additionally, in both groups some degree of airway remodeling is present. Still, the pathological disease state of asthma remission has been poorly investigated. Future research should focus on at least two aspects: further characterisation of the small airways and airway walls in order to determine histologically true remission, and more thorough biological pathway analyses to explore triggers that elicit this phenomenon. Ultimately, this will result in pharmacological targets that provide the potential to steer the course of asthma towards remission.

Lower respiratory tract infections appear to be the most important risk factor for current asthma in subarctic schoolchildren

AIM

The aim of this study was to identify possible risk factors for current asthma revealed by two studies in Northern Norway in 1985 and 2008 and to evaluate these factors contributing to the increased prevalence of asthma over these 23 years.

METHODS

As part of the 'Asthma and allergy study among schoolchildren in Nordland county' we performed a case-control study (70.0% attendance) comparing 153 children with current asthma (cases) to their non-asthmatic controls. The results from this 2008 study were compared to a similar case-control study (93.2% attendance) performed in 1985 based on 62 current asthmatics.

RESULTS

In 1985, the most important risk factors for current asthma were repeated lower respiratory tract infections (LRTIs) with adjusted odds ratio (aOR) 52.11, together with urticaria ever and atopic disease in the family. In 2008, the most important risk factors were food allergy with aOR 7.06, LRTIs during the first three years of life with aOR 5.80 and hospitalisation caused by LRTIs.

CONCLUSION

In both studies, LRTI was the most important risk factor for current asthma. Whether or not LRTIs have contributed to the increased asthma prevalence in this population over 23 years remains unresolved.

High-Sensitivity C-Reactive Protein and Allergic Endpoints in German Adolescents

BACKGROUND

Assessing high-sensitivity C-reactive protein (hs-CRP) in relation to allergic endpoints can shed light on both the mechanisms of allergic disease development and early non-communicable disease prevention. However, only a few epidemiological studies so far have investigated the relationship in children and adolescents, and the results were mixed.

OBJECTIVES

We sought to examine the interrelation between hs-CRP levels and allergic outcomes using a larger population size and a longitudinal study design.

METHODS

Complete data were available on 1,955 participants from the 15-years follow-up of the 2 large population-based German birth cohorts - GINIplus and LISA. Serum hs-CRP concentrations were measured using the immunoturbidimetric high-sensitive assay. Six allergic endpoints were used - doctor-diagnosed asthma, doctor-diagnosed eczema, doctor-diagnosed allergic rhinitis, food sensitization, aeroallergen sensitization, and any sensitization. We used generalized estimation equation models to assess the associations between hs-CRP levels and allergic endpoints.

RESULTS

Our longitudinal analyses did not detect any significant association between hs-CRP levels and any of the studied allergic outcomes (e.g., asthma, eczema, allergic rhinitis, food sensitization, aeroallergen sensitization, and any sensitization). The results were consistent in a series of sensitivity analyses.

CONCLUSIONS

Our study suggests that there is no association between hs-CRP levels and any of the allergic endpoints in German adolescents. However, whether allergic diseases are inflammatory conditions and which markers might be most sensitive, remain to be confirmed in future studies.

The Role of Early Life Food Sensitization in Adolescent Lung Function: Results from 2 Birth Cohort Studies

BACKGROUND

It is unclear whether early life food sensitization (as opposed to aeroallergen sensitization) is associated with subsequent poor lung function.

OBJECTIVES

We investigated the associations between food sensitization in the first 2 years of life and lung function at 12 to 18 years and whether these observed associations are mediated through aeroallergen sensitization or asthma.

METHODS

We used data from a high-risk cohort (Melbourne Atopy Cohort Study [MACS]) and a population-based "Influence of life-style-related factors on the development of the Immune System and Allergies in East and West Germany plus the influence of traffic emissions and genetics" (LISAplus) cohort. Food sensitization was assessed at 6, 12, and 24 months in MACS and 24 months in LISAplus. Lung function was evaluated by spirometry at 12 and 18 years in MACS and 15 years in LISAplus. Linear regression models were used to estimate the association with sensitization (food and/or aeroallergen) while adjusting for potential confounders.

RESULTS

Sensitization to food without aeroallergen at 6 months was associated with reduced forced expiratory volume in 1 second (FEV₁) at both 12 years (-153 mL; 95% confidence interval [CI] = -256 mL, -51 mL) and 18 years (-206 mL; 95% CI = -347 mL, -65 mL) in MACS. Similar results were observed for sensitization measured at 12 months but not at 24 months. Early-life asthma (but not aeroallergen sensitization) partially mediated these associations. Both cohorts showed that only aeroallergen sensitization at 24 months but not food sensitization was associated with lower adolescent lung function.

CONCLUSIONS

This study showed that food sensitization at 6 and 12 months was associated with reduced FEV₁ in adolescence. Our finding that this link is not completely mediated by either subsequent asthma or aeroallergen sensitization is novel and suggests that early food sensitization itself can be used to identify high-risk groups for poor lung health.

Serum perfluoroalkyl substances (PFAS) and risk of asthma and various allergies in adolescents. The Tromsø study Fit Futures in Northern Norway

BACKGROUND

Exposure to environmental pollutants may contribute to the development of asthma and other allergies. The aim of this study was to investigate possible associations between asthma and other allergies with exposure to perfluoroalkyl substances (PFASs) in adolescents from the Arctic region of Norway.

METHODS

The Tromsø study Fit Futures 1 (TFF1) and 3-year follow-up Fit Futures 2 study (TFF2) included 675 adolescents that completed a questionnaire about health conditions and underwent a clinical examination with blood tests and fractional nitric oxide (FeNO) measurement. Serum concentrations of 18 PFASs were measured by UHPLC-MS/MS method.

RESULTS

Total PFASs (ΣPFAS) serum concentration over 4th quartile was positively associated with asthma in the TFF1 (OR 3.35 (95% CI 1.54-7.29), p = 0.002). Total perfluorooctane sulfonate (ΣPFOS), linear PFOS (linPFOS), linear perfluorohexane sulfonate (linPFHxS) concentrations over 4th quartiles were associated with 2 times higher odds of asthma in the TFF1. The positive associations between ΣPFAS, ΣPFOS, linPFOS and asthma remained statistically significant in the TFF2. ΣPFAS and linPFHxS concentrations over 3rd tertiles were associated with positive marker of eosinophilic airways inflammation FeNO> 25 ppb. Concentrations of ΣPFOS and linPFOS over 3rd quartiles were positively associated with self-reported nickel allergy (OR 2.25 (95% CI 1.17-4.35) p = 0.016 and OR 2.53 (95% CI 1.30-4.90) p = 0.006, respectively). Allergic rhinitis, self-reported pollen allergy, food allergy and atopic eczema were not associated with PFASs concentrations.

CONCLUSIONS

This study of Norwegian adolescents showed a positive association between several PFASs and asthma, as well as between PFOS and nickel allergy.

Sleep problems, behavioural problems and respiratory health in children born extremely preterm: a parental questionnaire study

OBJECTIVE

To explore whether children born extremely preterm (EPT) with different types of sleep problems had more behavioural and respiratory health problems than EPT children without sleep problems.

DESIGN

Prospective, nationwide, questionnaire-based study. At 11 years of age, parents reported on four current sleep problems: difficulty falling asleep or frequent awakenings, snoring, daytime sleepiness and not recommended sleep duration (<9 hours). Behavioural problems were assessed by parents and teachers with the Strengths and Difficulties Questionnaire (SDQ). Parents assessed respiratory symptoms with the International Study of Asthma and Allergies in Childhood questionnaire and described use of asthma medication.

SETTING

Norway.

PATIENTS

EPT children.

MAIN OUTCOME MEASURES

Specified sleep problems, behavioural problems and respiratory health.

RESULTS

Data were obtained from 216 of 372 (58 %) of eligible children. All four specified sleep problems were associated with significantly higher parent-reported SDQ total-score (OR 1.1 for all), and except for not recommended sleep duration, also with higher teacher-reported SDQ total-score (OR 1.1 for all). Daytime sleepiness was strongly associated with wheezing last 12 months (OR 3.4), disturbed sleep due to wheezing (OR 3.9), wheeze during or after exercise (OR 2.9), use of inhaled corticosteroids or oral leukotriene modifiers (OR 3.4) and use of bronchodilators (OR 3.9). Snoring was associated with wheezing during or after exercise (OR 2.8) and current asthma (OR 4.2).

CONCLUSION

EPT children with different types of sleep problems had more behavioural and respiratory health problems than EPT children without sleep problems.

Asthma, Eczema, and Food Allergy in Children Following Liver Transplantation

OBJECTIVES

To describe the prevalence and the relationship between asthma, eczema, food allergy, and rhinitis in children after liver transplantation.

STUDY DESIGN

Children who were liver transplant recipients were investigated to assess whether the high prevalence of food allergies was accompanied by eczema, rhinitis, and asthma. Furthermore, we included 56 children with chronic liver disease to explore the risk of allergy, eczema, and asthma in this group.

RESULTS

After liver transplantation, children had higher prevalence of allergic reactions to food as compared with children with chronic liver disease (P < .001). Current asthma (P = .04) and eczema (P < .02) were observed more frequently in transplanted children as compared with children with chronic liver disease. For transplanted children who had ever received tacrolimus the relative risk (RR) of asthma was 1.7 (95% CI, 1.2-2.4; P = .02) as compared with children with chronic liver disease. Transplanted children with asthma had higher rates of sensitization to food allergens than those without asthma (RR, 3.6; 95% CI, 1.3-10.3; P = .01). The most frequent food allergens associated with asthma in transplanted children were milk (RR for asthma, 3.9; 95% CI, 1.6-9.4; P < .01), eggs (RR, 2.9; 95% CI, 1.2-7.0; P = .03), and peanuts (RR, 3.7; 95% CI, 1.6-8.3; P < .01). Food allergies occurred earlier than asthma, at 1.5 years after transplantation (IQR, 0.5-3.0 years) vs 2.5 years after transplantation (IQR, 1.0-4.5 years; P < .05). Food allergies were also associated with eczema, but not with sensitization to aero-allergens or rhinitis.

CONCLUSIONS

The high risk of food allergies in children who were liver transplant recipients was associated with eczema and asthma, but not rhinitis. The most frequent food allergens associated with asthma were milk, eggs, and peanuts.

Heating-induced contraction in airways smooth muscle: A possible causative factor of exercise-induced bronchoconstriction

Asthmatic patients often suffer from bronchoconstriction or asthma following breathing hot air or exposure to exercise due to raises the core body temperature. However, the direct effect of heating airways has not been studied yet. The aim of this study is to investigate the effect of heating on tracheal and bronchiolar smooth muscles. Isolated ovine tracheal strips and bronchiolar segments preparations were suspended in organ baths containing Krebs' solution for isometric tension recording. Tissues responses were examined during decreasing and elevating baths temperature (20 °C, 40 °C-45 °C and 50 °C). Cooling or heating induced rapid and reproducible contractions proportional with decreasing or increasing temperature respectively in tracheal and bronchiolar preparations. On reset to 37 °C the tone returned rapidly to basal level. Changing the bath's temperature from 37 °C to 20 °C or to 40 °C and 45 °C for tracheal strips or to 45 °C and 50 °C for bronchiolar segments induced contractions in both preparations. Changing the temperature below or above the normal body temperature (37 °C), leads to airways contractions. Heating induced contractions in tracheal and bronchiolar smooth muscle proportional to the heating temperature. Therefore, breathing hot air or elevation of body core temperature due to exercise can be considered possible causative factor of heating- or exercise-induced bronchoconstriction.

Plants Used by Bapedi Traditional Healers to Treat Asthma and Related Symptoms in Limpopo Province, South Africa

To the best of our knowledge there are presently no ethnobotanical surveys focusing on the utilisation of herbal remedies for asthma in South Africa. The present study is therefore an attempt to fill this gap in knowledge. A total of 140 Bapedi traditional healers (THs) practicing in the Capricorn, Sekhukhune, and Waterberg districts of the Limpopo Province (South Africa) were queried using semistructured questionnaires, supplemented by field observations during face-to-face interview. A total of 104 medicinal plant species (92 indigenous and 12 exotics) belonging to 92 genera, distributed across 54 botanical families, mostly the Asteraceae and Fabaceae (18.5%, for each) as well as Malvaceae (12.9%), were used as antiasthmatics and related symptoms by these THs. Most of the plants were trees and herbs (37.5%, for each), with root (57%), leaf (15.8%), and bark (7.5%), respectively, being the saliently used parts for preparation of remedies. Clerodendrum ternatum, Cryptocarya transvaalensis, Lasiosiphon caffer, Enicostema axillare, Mimusops obovata, Sclerocarya birrea, and Stylochaeton natalensis were widely used and valued by all THs across the surveyed districts. Furthermore, these taxa also scored both the highest use value and fidelity level indexes as asthma therapies. Overall, the larger number of species documented in the present study is recorded for the first time in literature as asthma and/or related symptoms remedies. Our study finding generally contributes towards an establishment of South African database of herbal therapies used traditionally against these conditions.

Molecular allergy diagnostics refine characterization of children sensitized to dog dander

BACKGROUND

Sensitization to dog dander is an important risk factor for rhinoconjunctivitis and asthma but is not sufficient for diagnosing dog allergy. Molecular allergy diagnostics offer new opportunities for refined characterization.

OBJECTIVES

We sought to study the association between sensitization to all presently known dog allergen components and clinical symptoms of dog allergy in children evaluated by using nasal provocation tests (NPTs).

METHODS

Sixty children (age, 10-18 years) sensitized to dog dander extract underwent NPTs with dog dander extract. Measurement of IgE levels to dog dander and to Can f 1, Can f 2, Can f 3, and Can f 5 was performed with ImmunoCAP, and measurement of IgE levels to Can f 4 and Can f 6 was performed with streptavidin ImmunoCAP. An IgE level of 0.1 kU_A/L or greater was considered positive.

RESULTS

There was an association between sensitization to an increasing number of dog allergen components and a positive nasal challenge result (P = .01). Sensitization to lipocalins (odds ratio [OR], 6.0; 95% CI, 1.04-34.5), in particular Can f 4 (OR, 6.80; 95% CI 1.84-25.2) and Can f 6 (OR, 5.69; 95% CI, 1.59-20.8), was associated with a positive NPT result. Monosensitization to Can f 5 was related to a negative NPT result (OR, 5.78; 95% CI, 1.01-33.0).

CONCLUSION

Sensitization to an increasing number of dog allergen components and to lipocalins is associated with dog allergy. Monosensitization to Can f 5 should not be regarded primarily as a marker for dog allergy.

Relationship between physical activity level and psychosocial and socioeconomic factors and issues in children and adolescents with asthma: a scoping review

BACKGROUND

Asthma is a heterogeneous chronic airway disease which may reduce capability for physical activity. In healthy peers, physical activity is influenced by psychosocial and socioeconomic factors. Knowledge about the role of these factors has not been mapped in children and adolescents with asthma.

OBJECTIVE

The main objective of this scoping review was to identify psychosocial and socioeconomic factors associated with physical activity level in children and adolescents with asthma in the literature. The specific objectives were to map the instruments used to measure these factors, report on the construction and validation of these instruments, map psychosocial and socioeconomic issues related to physical activity level reported in qualitative studies, and identify gaps in knowledge about the relationship between psychosocial and socioeconomic factors and physical activity level in children and adolescents with asthma.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

Children and adolescents with asthma aged six to 18 years.

CONCEPT

Psychosocial and socioeconomic factors related to physical activity level and participation.

CONTEXT

All physical activity contexts.

TYPES OF SOURCES

Quantitative and qualitative primary studies in English, with no date limit.

SEARCH STRATEGY

The databases searched included nine major databases for health and sports science, and five databases for unpublished studies. After screening and identification of studies, the reference lists of all identified reports were searched, and forward citation searches were conducted using four databases.

EXTRACTION OF THE RESULTS

The following data were extracted: (a) relevant study characteristics and assessment of physical activity level, (b) instruments used to assess psychosocial and socioeconomic factors, (c) association between physical activity level and these factors, (d) construction and validation of instruments, and (e) psychosocial and socioeconomic issues related to physical activity participation.

PRESENTATION OF THE RESULTS

Twenty-one quantitative and 13 qualitative studies were included. In cross-sectional studies, enjoyment, physical self-concept, self-efficacy, attitudes and beliefs about physical activity and health, psychological distress, health-related quality of life, and social support were more often reported as being correlated with physical activity level. In three studies, the construct validity was assessed by factor analysis and construct reliability tests for the study population. Qualitative studies reported 10 issues related to physical activity participation, and capability and being like peers were most commonly reported. There was no direct evidence that qualitative research informed the development or adjustment of instruments in quantitative studies.

CONCLUSIONS

Seven psychosocial factors correlated with physical activity level; capability and being like peers were the most commonly reported issues. Reports of the construction and validation of instruments were sparse.

Prospective Cohort Study of Breastfeeding and the Risk of Childhood Asthma

OBJECTIVES

To study whether the duration of breastfeeding and time for introduction of complementary foods was associated with the risk of childhood asthma.

STUDY DESIGN

We used data from the Norwegian Mother and Child Study, a nationwide prospective cohort study that recruited pregnant women from across Norway between 1999 and 2008. Children with complete data of breastfeeding up to 18 months and current age >7 years were eligible (n = 41 020). Asthma as the primary outcome was defined based on ≥2 dispensed asthma medications at age 7 years registered in the Norwegian Prescription Database. We used log-binomial regression models to obtain crude relative risks (RRs) in the main analysis, and adjusted for selected confounders in multivariable analyses.

RESULTS

For duration of any breastfeeding, 5.9% of infants breastfed <6 months (adjusted RR [aRR] 1.05, 0.93-1.19) and 4.6% breastfed 6-11 months (aRR 0.96, 0.87-1.07) had dispensed asthma medications at age 7 years compared with 4.6% of infants breastfed ≥12 months (P_trend .62). Infants still breastfed at 6 months, but introduced to complementary foods <4 months and 4-6 months, had an aRR of 1.15 (0.98-1.36) and 1.09 (0.94-1.27) respectively, compared with infants fully breastfed for 6 months (P_trend .09). Ages at introduction of solids or formula separately were not significant predictors (P_trend .16 and .08, respectively).

CONCLUSIONS

We found no association between duration of breastfeeding or age of introduction to complementary foods and asthma at age 7 years.

Respiratory morbidity through the first decade of life in a national cohort of children born extremely preterm

BACKGROUND

Advances in perinatal care have markedly increased the prospects of survival for infants born extremely preterm (EP). The aim of this study was to investigate hospitalisation rates and respiratory morbidity from five to 11 years of age in a prospective national cohort of EP children born in the surfactant era.

METHODS

This was a national prospective cohort study of all children born in Norway during 1999 and 2000 with gestational age (GA) < 28 weeks or birth weight < 1000 grams, and of individually matched term-born controls recruited for a regional subsample. Data on hospital admissions, respiratory symptoms, and use of asthma medication was obtained by parental questionnaires at 11 years of age.

RESULTS

Questionnaires were returned for 232/372 (62%) EP-born and 57/61 (93%) regional term-born controls. Throughout the study period, 67 (29%) EP-born and seven (13%) term-born controls were admitted to hospital (odds ratio (OR) 2.90, 95% confidence interval (CI): 1.25, 6.72). Admissions were mainly due to surgical procedures, with only 12% due to respiratory causes, and were not influenced by neonatal bronchopulmonary dysplasia (BPD) or low GA(≤ 25 weeks). Respiratory symptoms, asthma and use of asthma medication tended to be more common for EP-born, significantly so for medication use and wheeze on exercise. Neonatal BPD was a risk factor for medication use, but not for current wheeze. In multivariate regression models, home oxygen after discharge (OR 4.84, 95% CI: 1.38, 17.06) and parental asthma (OR 4.38, 95% CI: 1.69, 11.38) predicted current asthma, but neither BPD nor low GA were associated with respiratory symptoms at 11 years of age.

CONCLUSIONS

Hospitalisation rates five to 11 years after EP birth were low, but twice those of term-born controls, and unrelated to neonatal BPD and low GA. Respiratory causes were rare. Respiratory complaints were more common in children born EP, but the burden of symptoms had declined since early childhood.

Chronic respiratory disease and high altitude are associated with depressive symptoms in four diverse settings

SETTING

Depression is a prevalent comorbidity of chronic respiratory disease (CRD), and may indicate worse clinical outcomes. The relationship between depression and living with chronic hypoxia due to CRD or residence at altitude has received little attention in resource-poor settings.

OBJECTIVE

To investigate the association between CRD conditions and depressive symptoms in four settings in Peru.

DESIGN

We collected data on CRD and depressive symptoms in adults aged ⩾35 years. Depressive symptoms were measured according to the Center for Epidemiologic Studies Depression scale. Multivariable ordinal logistic regression was used to assess the adjusted odds of being in a higher category of depressive symptoms as a function of CRD.

RESULTS

We analyzed data from 2953 participants (mean age 55.3 years, 49% male). The prevalence of major depressive symptoms was 19%, with significant variation according to setting. Participants with at least one CRD (OR 1.34, 95%CI 1.06-1.69) and those living at altitude (OR 1.64, 95%CI 1.10-2.43) had an increased adjusted odds of being in a higher category of depressive symptoms.

CONCLUSION

We found a high prevalence of depressive symptoms, and a positive association between depressive symptoms with CRD and with living at altitude, both of which cause chronic hypoxia.

Prenatal exposure to perfluoralkyl substances (PFASs) associated with respiratory tract infections but not allergy- and asthma-related health outcomes in childhood

BACKGROUND

Prenatal exposure to perfluoralkyl substances (PFASs) has been reported to be associated with immunosuppression in early childhood, but with contradictory findings related to atopic and lung diseases.

AIM

We aimed to determine if prenatal exposure to PFASs is associated with asthma or other allergic diseases or respiratory tract infections in childhood.

METHODS

Nineteen PFASs were measured in cord blood available from 641 infants in the Environment and Childhood Asthma (ECA) prospective birth cohort study. The six most abundant PFASs were perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonamide (PFOSA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUnDA). Health outcomes were assessed at two and ten years of age, and included reported obstructive airways disease (wheeze by 10 years; asthma by 2 and 10 years; reduced lung function at birth; allergic rhinitis by 10 years), atopic dermatitis (AD) by 2 and 10 years, allergic sensitization by 10 years, and episodes of common respiratory tract infections (common cold by 2 years, lower respiratory tract infections (LRTI) by 10 years). The associations between exposure and health outcomes were examined using logistic and Poisson regression.

RESULTS

The number of reported airways infections were significantly associated with cord blood concentrations of PFAS; common colds by two years with PFUnDA (β = 0.11 (0.08-0.14)) and LRTIs from 0 to 10 years of age with PFOS (β = 0.50 (0.42-0.57)), PFOA (β = 0.28 (0.22-0.35)), PFOSA (β = 0.10 (0.06-0.14)), PFNA (β = 0.09 (0.03-0.14)) and PFUnDA (β = 0.18 (0.13-0.23)) concentrations. Neither reduced lung function at birth, asthma, allergic rhinitis, AD nor allergic sensitization were significantly associated with any of the PFASs.

CONCLUSION

Although prenatal exposure to PFASs was not associated with atopic or lung manifestations by 10 years of age, several PFASs were associated with an increased number of respiratory tract infections in the first 10 years of life, suggesting immunosuppressive effects of PFASs.

Which early life events or current environmental and lifestyle factors influence lung function in adolescents? - results from the GINIplus & LISAplus studies

BACKGROUND

Various factors may affect lung function at different stages in life. Since investigations that simultaneously consider several factors are rare, we examined the relative importance of early life, current environmental/lifestyle factors and allergic diseases on lung function in 15-year-olds.

METHODS

Best subset selection was performed for linear regression models to investigate associations between 21 diverse early life events and current factors with spirometric parameters (forced vital capacity, forced expiratory volume in 1 s and maximal mid-expiratory flow (FEF_25-75)) in 1326 participants of the German GINIplus and LISAplus birth cohorts. To reduce model complexity, one model for each spirometric parameter was replicated 1000 times in random subpopulations (N = 884). Only those factors that were included in >70% of the replication models were retained in the final analysis.

RESULTS

A higher peak weight velocity and early lung infections were the early life events prevalently associated with airflow limitation and FEF_25-75. Current environmental/lifestyle factors at age 15 years and allergic diseases that were associated with lung function were: indoor second-hand smoke exposure, vitamin D concentration, body mass index (BMI) and asthma status. Sex and height captured the majority of the explained variance (>75%), followed by BMI (≤23.7%). The variance explained by early life events was comparatively low (median: 4.8%; range: 0.2-22.4%), but these events were consistently negatively associated with airway function.

CONCLUSIONS

Although the explained variance was mainly captured by well-known factors included in lung function prediction equations, our findings indicate early life and current factors that should be considered in studies on lung health among adolescents.

Exercise-Induced Bronchospasm and Allergy

Sport is an essential part of childhood, with precious and acknowledged positive health effects but the impact of exercise-induced bronchoconstriction (EIB) significantly reduces participation in physical activity. It is important to recognize EIB, differentiating EIB with or without asthma if the transient narrowing of the airways after exercise is associated with asthmatic symptoms or not, in the way to select the most appropriate treatment among the many treatment options available today. Therapy is prescribed based on symptoms severity but diagnosis of EIB is established by changes in lung function provoked by exercise evaluating by direct and indirect tests. Sometimes, in younger children it is difficult to obtain the registration of difference between the preexercise forced expiratory volume in the first second (FEV1) value and the lowest FEV1 value recorded within 30 min after exercise, defined as the gold standard, but interrupter resistance, in association with spirometry, has been showed to be a valid alternative in preschool age. Atopy is the main risk factor, as demonstrated by epidemiologic data showing that among the estimated pediatric population with EIB up to 40% of them have allergic rhinitis and 30% of these patients may develop adult asthma, according with atopic march. Adopting the right treatment and prevention, selecting sports with no marked hyperventilation and excessive cooling of the airways, children with EIB can be able to take part in physical activity like all others.

More surprises in the global greenhouse: Human health impacts from recent toxic marine aerosol formations, due to centennial alterations of world-wide coastal food webs

Reductions of zooplankton biomasses and grazing pressures were observed during overfishing-induced trophic cascades and concurrent oil spills at global scales. Recent phytoplankton increments followed, once Fe-, P-, and N-nutrient limitations of commensal diazotrophs and dinoflagellates were also eliminated by respective human desertification, deforestation, and eutrophication during climate changes. Si-limitation of diatoms instead ensued during these last anthropogenic perturbations of agricultural effluents and sewage loadings. Consequently, ~15% of total world-wide annual asthma trigger responses, i.e. amounting to ~45 million adjacent humans during 2004, resulted from brevetoxin and palytoxin poisons in aerosol forms of western boundary current origins. They were denoted by greater global harmful algal bloom [HAB] abundances and breathing attacks among sea-side children during prior decadal surveys of asthma prevalence, compiled here in ten paired shelf ecosystems of western and eutrophied boundary currents. Since 1965, such inferred onshore fluxes of aerosolized DOC poisons of HABs may have served as additional wind-borne organic carriers of toxic marine MeHg, phthalate, and DDT/DDE vectors, traced by radio-iodine isotopes to potentially elicit carcinomas. During these exchanges, as much as 40% of mercury poisonings may instead have been effected by inhalation of collateral HAB-carried marine neurotoxic aerosols of MeHg, not just from eating marine fish. Health impacts in some areas were additional asthma and pneumonia episodes, as well as endocrine disruptions among the same adjacent humans, with known large local rates of thyroid cancers, physician-diagnosed pulmonary problems, and ubiquitous high indices of mercury in hair, pesticides in breast milk, and phthalates in urine.

Perceived exercise limitation in asthma: The role of disease severity, overweight, and physical activity in children

BACKGROUND

Children with asthma may be less physically active than their healthy peers. We aimed to investigate whether perceived exercise limitation (EL) was associated with lung function or bronchial hyper-responsiveness (BHR), socioeconomic factors, prenatal smoking, overweight, allergic disease, asthma severity, or physical activity (PA).

METHODS

The 302 children with asthma from the 10-year examination of the Environment and Childhood Asthma birth cohort study underwent a clinical examination including perceived EL (structured interview of child and parent(s)), measure of overweight (body mass index by sex and age passing through 25 kg/m² or above at 18 years), exercise-induced bronchoconstriction (forced expiratory volume in one-second (FEV₁ ) pre- and post-exercise), methacholine bronchial challenge (severe BHR; provocative dose causing ≥20% decrease in FEV₁ ≤ 1 μmol), and asthma severity score (dose of controller medication and exacerbations last 12 months). Multivariate logistic regression analyses were conducted to assess associations with perceived EL.

RESULTS

In the final model explaining 30.1%, asthma severity score (OR: 1.49, (1.32, 1.67)) and overweight (OR: 2.35 (1.14, 4.82)) only were significantly associated with perceived EL. Excluding asthma severity and allergic disease, severe BHR (OR: 2.82 (1.38, 5.76)) or maximal reduction in FEV₁ post-exercise (OR: 1.48 (1.10, 1.98)) and overweight (OR: 2.15 (1.13, 4.08) and 2.53 (1.27, 5.03)) explained 9.7% and 8.4% of perceived EL, respectively.

CONCLUSIONS

Perceived EL in children with asthma was independently associated with asthma severity and overweight, the latter doubling the probability of perceived EL irrespectively of asthma severity, allergy status, socioeconomic factors, prenatal smoking, or PA.

The prevalence of atopic diseases and the patterns of sensitization in adolescence

BACKGROUND

Atopic diseases are among the most common chronic diseases in adolescents, and it is uncertain whether the prevalence of atopic diseases has reached a plateau or is still increasing. The use of the ISAAC (International Study of Asthma and Allergy in Childhood) questionnaire has provided comparable prevalence rates from many countries, whereas studies including clinical examinations and strict diagnostic criteria are scarce. We aimed to investigate the prevalence of atopic diseases, the pattern of sensitization, and comorbidities at 14 years in a prospective birth cohort.

METHODS

The children were examined eight times from birth to 14 years. Visits included questionnaire-based interviews, clinical examination, skin prick test, and specific IgE.

RESULTS

Follow-up rate at 14 years was 66.2%. The 12-month prevalence of any atopic disease was high (40.3%) mostly due to a high prevalence of rhinoconjunctivitis (32.8%), whereas the prevalence of asthma was 12.9% and of atopic dermatitis 8.1%. In children with at least one atopic disease, 60% were sensitized, while only 16% of those without atopic diseases were sensitized. The frequency of sensitization depended on the phenotype. Among children with rhinoconjunctivitis only, rhinoconjunctivitis with concomitant asthma or atopic dermatitis or both 62.5%, 81.5%, 70%, and 100%, respectively, were sensitized, whereas it was 7.7% and 33.3% of children with only asthma or atopic dermatitis.

CONCLUSION

The prevalence of rhinoconjunctivitis was high in adolescence. Children with rhinoconjunctivitis with and without comorbidities were frequently sensitized. Children with asthma without concomitant allergic rhinoconjunctivitis were rarely sensitized.

Bronchial hyperresponsiveness in childhood: A narrative review

Bronchial hyperresponsiveness (BHR) is an important but not asthma-specific characteristic and can be assessed by direct and indirect methods, based on the stimulus causing airway obstruction. BHR has been proposed as a prognostic marker of asthma severity and persistence, and may also be used to control pharmacological management of asthma. The most recent data on the prevalence and development of BHR in childhood and its predictive value for subsequent asthma development in late adolescence and adulthood is discussed in this review. According to the BHR-related scientific articles written in the English language and indexed in the publicly searchable PubMed database, the prevalence of BHR varies based upon the methods used to assess it and the population examined. In general, however, BHR prevalence is reduced as children grow older, in both healthy and asthmatic populations. While asthma can be predicted by BHR, the predictive value is limited. Reduced lung function, allergic sensitization, female sex, and early respiratory illness have been identified as risk factors for BHR. The collective studies further indicate that BHR is a dynamic feature related to asthma, but asymptomatic BHR is also common. Ultimately, the prevalence of BHR varies depending on the population, the environment, and the evaluation methods used. While both the methacholine challenge and the exercise test may predict asthma in adolescence or early adulthood, the predictive value is higher for the methacholine challenge compared to the exercise test. The collective data presented in the present study demonstrate how BHR develops through childhood and its relation to bronchial asthma.

Exercise and asthma: an overview

The terms 'exercise-induced asthma' (EIA) and 'exercise-induced bronchoconstriction' (EIB) are often used interchangeably to describe symptoms of asthma such as cough, wheeze, or dyspnoea provoked by vigorous physical activity. In this review, we refer to EIB as the bronchoconstrictive response and to EIA when bronchoconstriction is associated with asthma symptoms. EIB is a common occurrence for most of the asthmatic patients, but it also affects more than 10% of otherwise healthy individuals as shown by epidemiological studies. EIA and EIB have a high prevalence also in elite athletes, especially within endurance type of sports, and an athlete's asthma phenotype has been described. However, the occurrence in elite athletes shows that EIA/EIB, if correctly managed, may not impair physical activity and top sports performance. The pathogenic mechanisms of EIA/EIB classically involve both osmolar and vascular changes in the airways in addition to cooling of the airways with parasympathetic stimulation. Airways inflammation plays a fundamental role in EIA/EIB. Diagnosis and pharmacological management must be carefully performed, with particular consideration of current anti-doping regulations, when caring for athletes. Based on the demonstration that the inhaled asthma drugs do not improve performance in healthy athletes, the doping regulations are presently much less strict than previously. Some sports are at a higher asthma risk than others, probably due to a high environmental exposure while performing the sport, with swimming and chlorine exposure during swimming as one example. It is considered very important for the asthmatic child and adolescent to master EIA/EIB to be able to participate in physical activity on an equal level with their peers, and a precise early diagnosis with optimal treatment follow-up is vital in this aspect. In addition, surprising recent preliminary evidences offer new perspectives for moderate exercise as a potential therapeutic tool for asthmatics.

Decline in admissions for childhood asthma, a 26-year period population-based study

BACKGROUND

The prevalence of childhood asthma has increased, although the rate of hospitalization for asthma seems to decrease. In Norway, the rate of hospital admission for childhood asthma from 1984 to 2000 increased. The aim of this study was to assess further trends in hospital admissions for childhood asthma up to 2010.

METHODS

A population-based study including children 1-13 yrs of age hospitalized for asthma during six periods from 1984/1985 to 2009/2010 in Rogaland, Norway, was performed. Medical records from 1536 admissions (1050 children) were studied; and gender, age, number of admissions, length of hospital stay, medications and symptoms were recorded.

RESULTS

For all age groups, the rate of admissions per 10.000 increased from 20.1 in 1984/85 to 33.7 in 1989/90, but declined to 14.4 in 2009/2010. Rates were highest in boys (OR 1.87; 95% CI: 1.69, 2.09), younger age groups (OR 2.51; 2.38, 2.64) and decreased from 1984 to 2010 (OR 0.92; 0.88, 0.94). The rates of readmissions were higher than for primary admissions (OR 1.33; 1.19, 1.47). From 1984 to 2010, there was an increased use of inhaled corticosteroids prior to admission (6 to 51%) and started at discharge (7 to 37%), and systemic steroids given during admission (19 to 83%).

CONCLUSION

There has been a substantial decline in the rate of hospital admissions for childhood asthma after 1989/1990, with major differences between age groups and genders. The decline could be due to improved care of children with asthma or a real reduction in asthma exacerbations.

Predicting asthma morbidity in children using proposed markers of Th2-type inflammation

BACKGROUND

Assessment of inflammation is becoming a common practice in the clinical work-up of children with persistent asthma. Biomarkers of Th2-mediated inflammation include blood eosinophils (B-Eos), exhaled nitric oxide (FeNO), total serum IgE (S-IgE), and serum periostin. The aim of this study was to investigate the associations between asthma morbidity and increased levels of these biomarkers in pediatric asthma.

METHODS

School-age children (n = 96) with various manifestations of persistent asthma were included in this nationwide Swedish study. The protocol included the asthma control test, Juniper's quality of life questionnaire (QoL), assessment of pulmonary function, bronchial hyperresponsiveness, height-adjusted FeNO, blood sampling for S-IgE, B-Eos, and periostin, and high-resolution computed tomography (HRCT) of the lungs.

RESULTS

Children with both high levels of height-adjusted FeNO and B-Eos were younger (p = 0.001), had more often severe asthma (p = 0.015), were more allergic (p < 0.001), had a reduced asthma control (p = 0.035), reduced QoL (p = 0.035), more exacerbations (p = 0.004), reduced FEV1/FVC (p = 0.001), and increased bronchial hyperresponsiveness (p < 0.001) as well as greater bronchial wall thickening on HRCT (p = 0.022) compared to those with low levels of both biomarkers. Grouping children according to high and low serum periostin levels did not relate to differences in clinical characteristics and biomarkers.

CONCLUSIONS

Assessment of both local and systemic Th2-mediated inflammation by the analysis of easily attainable biomarkers such as exhaled NO and blood eosinophils has a high predictive value for the identification of children with the highest asthma morbidity. Adjusting FeNO values according to the individual child's height increases the clinical usefulness of this biomarker.

Hyperventilation syndrome in adolescents with and without asthma

BACKGROUND

Data on the prevalence of hyperventilation syndrome (HVS) in adolescents are scanty.

OBJECTIVES

To determine the prevalence of HVS in a population of adolescents with and without asthma, and to verify whether HVS was related to asthma activity.

METHODS

A population of adolescents was asked to self-complete a questionnaire, including the Nijmegen questionnaire to assess HVS, and a standardized asthma questionnaire.

RESULTS

Seven hundred and sixty questionnaires were suitable for analysis. One hundred and twenty subjects (15.8%) were classified as asthmatic. Forty-seven subjects (6.2%) had a Nijmegen score ≥ 23, which was suggestive of HVS. Symptoms indicative of HVS were ten times more common in subjects with asthma (25%) than in those without asthma (2.5%). Nijmegen score was significantly higher in subjects with lifetime asthma (P < 0.001), current episodic asthma (P < 0.05) and current active asthma (P < 0.001) than in those with no asthma. In the whole population, girls presented HVS more frequently than boys (P < 0.001). There was a significant effect of gender (females, OR 3.2) and status of asthma (lifetime asthma, OR 11.2; current episodic asthma, OR 8.9; current active asthma, OR 41.5) on the probability of suffering from HVS.

CONCLUSIONS

The prevalence of symptoms indicative of HVS in an unselected population of adolescents was relatively high. Symptoms were more common in girls and in subjects with asthma, and there was a significant effect of asthma activity on the probability of suffering from HVS. Further studies need to be performed in order to validate a screening tool for HVS in both adolescents and asthmatic subjects.

Exercise and asthma: an overview

The terms 'exercise-induced asthma' (EIA) and 'exercise-induced bronchoconstriction' (EIB) are often used interchangeably to describe symptoms of asthma such as cough, wheeze, or dyspnoea provoked by vigorous physical activity. In this review, we refer to EIB as the bronchoconstrictive response and to EIA when bronchoconstriction is associated with asthma symptoms. EIB is a common occurrence for most of the asthmatic patients, but it also affects more than 10% of otherwise healthy individuals as shown by epidemiological studies. EIA and EIB have a high prevalence also in elite athletes, especially within endurance type of sports, and an athlete's asthma phenotype has been described. However, the occurrence in elite athletes shows that EIA/EIB, if correctly managed, may not impair physical activity and top sports performance. The pathogenic mechanisms of EIA/EIB classically involve both osmolar and vascular changes in the airways in addition to cooling of the airways with parasympathetic stimulation. Airways inflammation plays a fundamental role in EIA/EIB. Diagnosis and pharmacological management must be carefully performed, with particular consideration of current anti-doping regulations, when caring for athletes. Based on the demonstration that the inhaled asthma drugs do not improve performance in healthy athletes, the doping regulations are presently much less strict than previously. Some sports are at a higher asthma risk than others, probably due to a high environmental exposure while performing the sport, with swimming and chlorine exposure during swimming as one example. It is considered very important for the asthmatic child and adolescent to master EIA/EIB to be able to participate in physical activity on an equal level with their peers, and a precise early diagnosis with optimal treatment follow-up is vital in this aspect. In addition, surprising recent preliminary evidences offer new perspectives for moderate exercise as a potential therapeutic tool for asthmatics.

Early risk factors for pubertal asthma

BACKGROUND

Early life risk factors are previously described for childhood asthma, but less is known related to asthma in adolescence. We aimed to investigate early risk factors (before 2 years) for pubertal asthma and secondarily for pubertal asthma phenotypes based upon allergic comorbidities.

METHODS

Based on data from 550 adolescents in the prospective birth cohort 'Environment and Childhood Asthma' study, subjects were categorized by recurrent bronchial obstruction (rBO) 0-2 years, asthma 2-10 years, and pubertal asthma from 10 to 16 years including incident asthma in puberty and asthma in remission from 10 to 16 years or as never rBO/asthma 0-16 years. Asthma in puberty was further classified based on the comorbidities atopic dermatitis and allergic rhinitis (AR) from 10 to 16 years. Twenty-three common asthma risk factors identified by 2 years of age, including frequency and persistence of bronchial obstruction (severity score), were analysed by weighted logistic regression for each phenotype.

RESULTS

In adjusted models, the risk of pubertal asthma increased significantly with higher severity score, parental rhinitis, being the firstborn child, and familial stress around birth. Pubertal asthma in remission was significantly associated with severity score and number of lower respiratory tract infections and inversely associated with breastfeeding beyond 4 months. Pubertal incident asthma was more common among firstborn children. All asthma phenotypes with allergic diseases were significantly associated with severity score, whereas familial perinatal stress increased the risk of asthma only. Asthma combined with AR was associated with parental asthma and being firstborn, whereas the risk of asthma with both atopic dermatitis and AR increased with higher paternal education, atopic dermatitis, being firstborn, and familial perinatal stress.

CONCLUSION AND CLINICAL RELEVANCE

Important early risk factors for pubertal asthma were early airways obstruction, parental rhinitis, being the firstborn child, and perinatal familial stress.