Epidemiology of asthma and recurrent wheeze in childhood

Maternal exercise during pregnancy is associated with reduced risk of asthma in the child: A prospective birth cohort study

BACKGROUND

The means of primary prevention of asthma are limited. Maternal physical activity during pregnancy promotes fetal lung development and the newborn's lung function; thus, it could lower asthma risk and aid in asthma prevention. The objective of this study is to determine whether maternal physical activity during pregnancy is associated with asthma development in the child.

METHODS

The study population included 963 mother-infant pairs from the prospective Kuopio Birth Cohort study. Data on maternal physical activity during pregnancy, confounding factors, and children's asthma at 5 to 7 years of age were obtained from the Kuopio University Hospital birth registry and questionnaires.

FINDINGS

Maternal physical activity during pregnancy, when practiced three or more times per week, was associated with a reduced risk of asthma in the child, with an adjusted odds ratio of 0.54 (95% confidence interval 0.33-0.89; p = 0.02). The association was stable across a comprehensive set of adjustments, including length of gestation, mode of delivery, and maternal health indicators (e.g., asthma, smoking, pre-pregnancy body mass index and weight gain during pregnancy, infections, medication, healthy diet, stress), as well as various family environment variables.

CONCLUSIONS

Maternal physical activity during pregnancy may be associated with marked protection of asthma in childhood and should be studied further as an applicable measure for asthma prevention.

FUNDING

The study has been financially supported by grants from the Academy of Finland (no. 349427), the Emil Aaltonen Foundation, the Finnish Cultural Foundation, the Yrjö Jahnsson Foundation, the Juho Vainio Foundation (no. 202200461), the Kuopio Area Respiratory Foundation, and the Ida Montini Foundation.

Single inhaler combination inhaled corticosteroid-formoterol as both maintenance and reliever (SMART) compared with a step up of treatment with fixed-dose inhaled corticosteroid-long-acting β2-agonist maintenance with a short-acting β2-agonist as reliever in adolescents and adults with poorly controlled asthma in Colombia: a cost-utility analysis

OBJECTIVE

The aim of the present study was to determine the cost-utility of single inhaler combination inhaled corticosteroid and a long-acting β2-agonist (ICS/LABAs) as both maintenance and reliever (SMART) compared with a step-up maintenance treatment with a fixed medium to high dose of ICS combined with LABA and a short-acting β2-agonist (SABA) as reliever (ICS-LABA maintenance plus SABA) among patients aged 12 years or more with poorly controlled asthma in Colombia.

METHODS

A Markov-type model was developed to estimate the costs and health outcomes of a simulated cohort of patients aged 12 years or more with uncontrolled asthma treated for 12 months. The main effectiveness data were obtained from a recent meta-analysis. The main outcome was the variable ''quality-adjusted life-years'' (QALYs).

RESULTS

The base-case analysis showed that the budesonide/formoterol (BUD/FORM) SMART strategy was associated with lower overall treatment costs (US $3,062.37 vs. $4,462.02 average cost per patient over 12 months) and the greatest gain in QALYs (0.8511 vs. 0.8258 QALYs on average per patient over 12 months) compared with ICS-LABA maintenance plus SABA at step 4, thus leading to dominance.

CONCLUSIONS

In patients aged 12 years or more with uncontrolled asthma at GINA step 3 or 4, the BUD/FORM SMART strategy at either step 3 or 4 is cost-effective compared with the ICS-LABA maintenance plus SABA at step 4 strategy, because it shows a greater gain in QALYs at lower total treatment costs.

Higher risk of osteoporosis in adult-onset asthma than childhood-onset asthma: from genetic and prospective evidence

Both COA and AOA have a genetically causal effect on osteoporosis. COA and AOA were independently associated with incident osteoporosis, and the risk was greatly higher in AOA. Besides corticosteroids, the increased risk of osteoporosis among asthma patients should be attributed to genetic susceptibility and other asthma medications.

PURPOSE/INTRODUCTION

Childhood-onset asthma (COA) differs with adult-onset asthma (AOA) on genetic susceptibility, severity, and co-morbidities. Whether COA or AOA is independently associated with osteoporosis is unexplored. We aimed to determine the effects of COA and AOA on osteoporosis at genetic and individual level.

METHODS

We used two-sample Mendelian randomization analysis to explore the causal effects of COA and AOA on osteoporosis. In the UK Biobank cohort, we included 478,289 osteoporosis-free participants at baseline (2006-2010). Participants were classified as non-asthma, COA, and AOA at recruitment. Multivariate Cox regression analysis was used to evaluate the effects of COA, AOA, and multiple asthma medications on incident osteoporosis risk.

RESULTS

COA and AOA were causally related to osteoporosis, with odds ratio of 1.007 (95% confidence interval (CI), 1.0003-1.0132) and 1.012 (95% CI, 1.002-1.023), respectively. Multivariate Cox regression analysis suggested that COA (hazard ratio (HR), 1.46; 95% CI, 1.32-1.61) and AOA (HR, 1.70; 95% CI, 1.61-1.80) were independently associated with incident osteoporosis, and the risk was greatly higher in AOA (HR, 1.51; 95% CI, 1.34-1.70). In addition to corticosteroids, monotherapy with leukotriene modifiers (HR, 1.70; 95% CI, 1.20-2.42), long-acting beta agonists (HR, 1.49; 95% CI, 1.18-1.87), and short-acting beta agonists (HR, 1.72; 95% CI1.01-2.93) were independently associated with a higher risk of osteoporosis.

CONCLUSIONS

Both COA and AOA have a genetically causal effect on osteoporosis, and the risk of osteoporosis is greatly higher in AOA. Besides corticosteroids, the increased risk of osteoporosis among asthma patients should be attributed to genetic susceptibility and other asthma medications.

Clinical manifestations of respiratory syncytial virus infection and the risk of wheezing and recurrent wheezing illness: a systematic review and meta-analysis

BACKGROUND

Respiratory syncytial virus (RSV) infection in infants is a global health priority. We aimed to investigate the common manifestations of RSV infection by age group and human development index (HDI) level and to assess its association with the development of wheezing and recurrent wheezing illness.

METHODS

We searched the literature published between January 1, 2010 and June 2, 2022 in seven databases. Outcomes included common manifestations and long-term respiratory outcomes of RSV infection in children. Random- and fixed-effect models were used to estimate the effect size and their 95% confidence intervals. Subgroup analysis was conducted by age and HDI levels. This review was registered in PROSPERO (CRD42022379401).

RESULTS

The meta-analysis included 47 studies. The top five manifestations were cough (92%), nasal congestion (58%), rhinorrhea (53%), shortness of breath (50%), and dyspnea (47%). The clinical symptoms were most severe in infants. In our analysis, compared to very high and high HDI countries, fewer studies in medium HDI countries reported related manifestations, and no study in low HDI countries reported that. The RSV-infected infants were more likely to develop wheezing than the non-infected infants [odds ratio (OR), 3.12; 95% CI, 2.59-3.76] and had a higher risk of developing wheezing illnesses after recovery (OR, 2.60; 95% CI, 2.51-2.70).

CONCLUSIONS

Cough and shortness of breath are common manifestations of RSV infection. More attention should be given to infants and areas with low HDI levels. The current findings confirm an association between RSV infection and wheezing or recurrent wheezing illness.

Influence of Maternal Fish Oil Supplementation on the Risk of Asthma or Wheeze in Children: A Meta-Analysis of Randomized Controlled Trials

Background

Previous studies evaluating the influences of maternal fish oil supplementation on the risk of asthma or wheeze in children showed inconsistent results. We performed a meta-analysis or randomized controlled trials (RCTs) to systematically evaluate the efficacy of maternal fish oil supplementation for asthma or wheeze.

Methods

Relevant RCTs were obtained by search of PubMed, Embase, and Cochrane's Library databases. A random-effects model incorporating the potential publication bias was used to pool the results.

Results

Ten RCTs with 3,676 infants were included. Compared to control, maternal supplementation with fish oil was not associated with a reduced risk of asthma or wheeze [odds ratio (OR): 0.91, 95% confidence interval (CI): 0.72-1.14, P = 0.40] with mild heterogeneity (I 2 = 28%). Subgroup analyses showed that maternal fish oil supplementation significantly reduced the risk of asthma (OR: 0.56, 95% CI: 0.35-0.91, P = 0.02; I 2 = 0%), but not the risk of wheeze (OR: 1.12, 95% CI: 0.90-1.41, P = 0.32; I 2 = 0%). In addition, maternal fish oil supplementation was associated with reduced risk of asthma or wheeze in high-dose studies (≥1,200 mg/d, OR: 0.65, 95% CI: 0.48-0.87, P = 0.003; I 2 = 0%), but not in low-dose studies (<1,200 mg/d, OR: 1.10, 95% CI: 0.88-1.38, P = 0.39; I 2 = 0%, P for subgroup difference = 0.005). Study characteristics such as the risk of the infants, timing of supplementation, and follow-up duration did not significantly affect the results.

Conclusions

Maternal fish oil supplementation may reduce the risk of clinically diagnosed asthma in children, particularly with high-dose fish oil.

Prevalence of Recurrent Hospital Admission in Children with Recurrent Wheezing in Babylon Province

BACKGROUND: Occurring of recurrent wheezing attacks signify a significant healthcare problem and considered one of the most common causes of emergency unit admission and hospitalizations. AIM: The aim of study is to determine the associations of recurrent hospital admissions in children with recurrent wheezing. METHODS: Cross-sectional descriptive study of 102 children with recurrent wheezy chest. Data collected from admitted patients with recurrent wheezing by direct interview with the patients’ families. Patients were 6 months to 5 years old. Data collected including age, gender, place of living whether urban or rural, prematurity, no. of people at home, history of NCU admission, history of ICU admission, exclusive breast feeding for 1st 6 months, anemia, GERD, history of atopy, exposure to smoking, inhaler use, and CXR findings. RESULTS: About 79.41% of children have 1-3 times admission in hospital, significant association between the no. of hospitalization and History of ICU admission, children with more than 3 times admission to hospital present with GERD with significant association. Significant association with more than 3 times admission to hospital have previous history of exposure to smoking, inhaler use and X-ray finding. CONCLUSION: One to three years old children is the most common age they have recurrent wheezing, most children with recurrent wheezy chest have more than 3 times hospitalization, most babies have previous history of ICU admission, GERD and exposure to smoking.

Early Adverse Experiences and Repeated Wheezing From 6 to 30 Months of Age: Investigating the Roles of Hypothalamic-Pituitary-Adrenal Axis Functioning, Child Sex, and Caregiving Sensitivity

This study examined associations among early adversity, diurnal cortisol, child sex, and caregiver sensitivity at age 6 months in relation to wheezing in children (47% male) followed to 30 months. Analyses included 676 mother-child dyads, 393 of whom completed an observational caregiver sensitivity measure. Participants were primarily ethnic minorities (42.7% Black, 25.4% Hispanic); 22.1% of children had ≥ 1 wheezing episode. Higher adversity was associated with increased wheeze frequency and blunted diurnal cortisol slope. The indirect effect of adversity on wheezing through cortisol slope was significant for females, but not males. Higher caregiver sensitivity was protective against wheezing for males, but not females, with high cortisol. Findings suggest complex associations among adversity, cortisol, child sex, and caregiver sensitivity in predicting wheezing.

Environmental exposure during pregnancy and the risk of childhood allergic diseases

BACKGROUND

Allergic diseases are one of the most common and important diseases that can exert hazardous effects on children's health. The prevalence of allergic diseases in childhood is gradually increasing all over the world in recent decades. Known causes of these diseases include anomalous immune responses and allergic inflammatory reactions, but the causes of allergic diseases in childhood are complex.

DATA SOURCES

PubMed, Cochrane Library, Embase and Web of Science were searched for articles focusing on environmental exposure during pregnancy and the risk of childhood allergic diseases, including asthma and atopic dermatitis, and the possible underlying mechanism.

RESULTS

In terms of environmental factors, allergic diseases in childhood are closely related to environmental chemical exposure during pregnancy, including bisphenols, phthalates acid esters, perfluorochemicals, polybrominated diphenyl ethers, and polychlorinated biphenyls. However, allergic diseases in childhood are also closely associated with maternal dietary nutrition, maternal intake of drugs, such as acetylsalicylic acid (aspirin), paracetamol and antibiotics, and maternal lifestyle.

CONCLUSIONS

Several harmful environmental factors during pregnancy can result in the interruption of the function of helper T cells (Th1/Th2), cytokines and immunoglobulins and may activate allergic reactions, which can lead to allergic diseases during childhood.

The Rhinobiome of Exacerbated Wheezers and Asthmatics: Insights From a German Pediatric Exacerbation Network

Although the nose, as a gateway for organism–environment interactions, may have a key role in asthmatic exacerbation, the rhinobiome of exacerbated children with asthma was widely neglected to date. The aim of this study is to understand the microbiome, the microbial immunology, and the proteome of exacerbated children and adolescents with wheeze and asthma. Considering that a certain proportion of wheezers may show a progression to asthma, the comparison of both groups provides important information regarding clinical and phenotype stratification. Thus, deep nasopharyngeal swab specimens, nasal epithelial spheroid (NAEsp) cultures, and blood samples of acute exacerbated wheezers (WH), asthmatics (AB), and healthy controls (HC) were used for culture (n = 146), 16 S-rRNA gene amplicon sequencing (n = 64), and proteomic and cytokine analyses. Interestingly, Proteobacteria were over-represented in WH, whereas Firmicutes and Bacteroidetes were associated with AB. In contrast, Actinobacteria commonly colonized HCs. Moreover, Staphylococcaceae, Enterobacteriaceae, Burkholderiaceae, Xanthobacteraceae, and Sphingomonadaceae were significantly more abundant in AB compared to WH and HC. The α-diversity analyses demonstrated an increase of bacterial abundance levels in atopic AB and a decrease in WH samples. Microbiome profiles of atopic WH differed significantly from atopic AB, whereby atopic samples of WH were more homogeneous than those of non-atopic subjects. The NAEsp bacterial exposure experiments provided a disrupted epithelial cell integrity, a cytokine release, and cohort-specific proteomic differences especially for Moraxella catarrhalis cultures. This comprehensive dataset contributes to a deeper insight into the poorly understood plasticity of the nasal microbiota, and, in particular, may enforce our understanding in the pathogenesis of asthma exacerbation in childhood.

Allergen detection and analysis in Eastern Taiwan area

Objective:

Environmental factors, eating habits, and different ages might affect the profiles of allergy sensitization. The purpose of this study was to survey the different profiles of allergen sensitization in different ages in eastern Taiwan.

Materials and Methods:

We analyzed the allergic patients who had allergen sensitization examinations by the Phadiatop (atopy screen; IBT Laboratories, Lenexa, KS, USA) and the Pharmacia CAP System method at Haulien Tzu Chi Hospital from January 2010 to December 2015. Results were compared in different ages.

Results:

A total of 15,455 patients were analyzed. The food and aeroallergen screen sensitization rate of children was significantly higher than that of adults (44.0% vs. 9.9% and 61.9% vs. 52.2% P < 0.05). Children had statistically significantly higher cow milk allergen-specific sensitization rate than that of adults (32.9% vs. 5.8% P < 0.05). The higher sensitization of shrimp occurred in adults than children. (33.6% vs. 24.8% P < 0.05).

Conclusion:

Our data demonstrate that children have higher cow milk allergy sensitization and adults have higher sensitization of shrimp.

Proximity to Major Roads and Risks of Childhood Recurrent Wheeze and Asthma in a Severe Bronchiolitis Cohort

Air pollution exposures have been suggested as risk factors for childhood respiratory diseases. We investigated proximity to major roads, an indicator of air pollution exposure, and its associations with childhood recurrent wheeze and asthma. We used data from a multicenter prospective cohort study of 921 infants hospitalized for bronchiolitis and recruited from 14 U.S. states. Primary exposure was residential proximity to the nearest major road at birth through age 3 years. Residential distance from nearest major road was divided into four categories: <100, 100–200, 201–300, and >300 m. Outcomes were parent-reported recurrent wheeze by age 3 years and asthma by age 5 years. Associations between residential proximity to major roads and respiratory outcomes were investigated using multivariable Cox proportional hazards modeling and logistic regression, adjusted for confounders. Out of 920 participants with home address data, pooled estimates identified 241 (26%) participants resided within 300 m of a major road, 296 (32%) developed recurrent wheeze by age 3, and 235 out of 858 participants (27%) developed asthma by 5 years. Participants who resided close to a major road had the highest risk of recurrent wheeze (adjusted hazards ratio for <100 m, 1.59, 95%CI: 1.08–2.33) and asthma (adjusted odds ratio for 201–300 m, 1.62, 95%CI: 1.16–2.25), compared to those residing >300 m from a major road. Proximity to major roads is associated with increased risks of recurrent wheeze and asthma in young children.

Significant Clinical Associations Between Exposure Type Factors and Recurrent Wheezing and Asthma in Children

The study aimed to identify certain factors related to family history, pathological conditions, or exposure-type that are significantly correlated with recurrent wheezing and/or asthma in children. One hundred nine children with recurrent wheezing and 44 children with asthma were studied in order to identify the degree of correlation of these conditions with familial history of asthma or atopy, child’s age group, gender, premature birth, perinatal asphyxia, neonatal infection, and antibiotic treatment during the neonatal period, history of atopy and obesity and histamine intolerance, nasopharyngeal bacterial colonization, pneumonia with bronchospasm. The clinical picture of these two diseases was also compared regarding the severity of exacerbations and their response to controller therapy. The medium age of children diagnosed with recurrent wheezing was significantly lower than those diagnosed with asthma (5.64 vs. 9.01 years; p<0.001). Inside the recurrent wheezing group, age distribution differed significantly from the asthma group (p-value <0.001). Atopy was the only pathological condition significantly associated with asthma (56.0%) when compared with the recurrent wheezing group (30.2%) with a relative risk value of 1.34 (p<0.004). For patients colonized with Staphylococcus aureus, the medium number of wheezing exacerbations was significantly higher (p<0.049). Approximately 91% of patients in the recurrent wheezing group and 71% from the asthma group responded to appropriate controller treatment. Our study showed a significant association between asthma and atopy, justifying the need to monitor asthma risk in a child with wheezing and atopy. Nasal carriage of Staphylococcus aureus proved to be significantly associated with the recurrence of wheezing in children.

Impulse oscillometry: pulmonary function assessment in preschool children

OBJECTIVES

In contrast to spirometry, which requires active participation of the individual and is challenging for the preschool age group, the impulse oscillometry system comprises a test that minimizes the degree of coordination required. The study aimed to compare the results of Impulse Oscillometry System (IOS) in children with and without respiratory symptoms.

METHODS

A cross-sectional study was conducted in children aged between 3 and 6 years. A short version of the ATS-DLD-78-C questionnaire validated for Brazilian children was applied to identify two groups: children with and without respiratory symptoms. The IOS analysis was carried out measuring the following parameters in triplicate: resistance at 5 Hz (R5Hz) and 20 Hz (R20Hz), respiratory reactance at 5 Hz (X5Hz), and R5-R20Hz before and after bronchodilator application.

RESULTS

A total of 76 preschoolers were selected, 55 (72.4%) of whom had respiratory complaints. The coefficient of variability of R5Hz was ≤17% in 70/76 (92.1%) of the children. Resistances at R5Hz and R5-R20Hz in the children with respiratory complaints reached values higher than those of children without symptoms before bronchodilation.

CONCLUSIONS

The results obtained for resistance using IOS in children with respiratory symptoms were higher in the pre-bronchodilator examination for R5Hz and R5-R20Hz compared to those of children without respiratory symptoms.

EXPERT OPINION

Prospective investigations suggest that irreversible changes in lung function begin in infancy, before reaching school age. Pulmonary function follow-up in children with recurrent wheezing or asthma is important for confirmation of diagnosis and evaluation of the disease severity. The Impulse Oscillometry System (IOS) can be useful in assessing children's pulmonary function since it requires minimal patient cooperation and can be successfully applied to preschool children being an alternative to individuals who have difficulty performing spirometry.

Asthma prevalence and risk factors in school children: The RESPIR longitudinal study

OBJECTIVES

To analyze the incidence of wheezing in the first six years of life; the prevalence of asthma at six years of age; and the associated risk factors, in a population from Valencia, Spain.

METHODS

A prospective longitudinal study was made of a cohort of 636 newborn infants, with follow-up of the clinical records and the completion of questionnaires up to the age of six years.

RESULTS

The prevalence of asthma at six years of age was 12.8%. Up until that age, 63% of the study population had experienced at least one episode of wheezing, and 35% had suffered recurrent wheezing (three or more episodes). Admission due to wheezing was associated to school asthma. The following risk factors were identified: atopic dermatitis (OR: 2.1; 95%CI: 1.2-3.5), the presence of at least one episode of wheezing in the first year (OR: 1.8; 95%CI: 1.1-2.9), prematurity (OR: 2.5; 95%CI: 1.2-5.1), and a family history of asthma (OR: 2.2; 95%CI: 1.2-4.1).

CONCLUSIONS

The prevalence of asthma at six years of age in our population is similar to that described in other longitudinal studies. An important increase is observed in the cumulative incidence of wheezing and of recurrent wheezing up to three years of age, followed by stabilization. The most relevant risk factors for developing asthma at six years were atopic dermatitis, wheezing during the first year, prematurity, and a family history of asthma. Full-term pregnancy and the minimization of respiratory infections at an early age could reduce the prevalence of asthma at six years of age in our population.

Infant wheezing and prenatal antibiotic exposure and mode of delivery: a prospective birth cohort study

Introduction: Assessments on whether prenatal antibiotic exposure and mode of delivery increase the risk of wheezing in infants and toddlers are inconsistent. Our goal is to evaluate the association between prenatal antibiotic use and Cesarean section with three subtypes of wheezing in infancy.Methods: An ongoing prospective three generations cohort study provides data on prenatal antibiotic use and mode of delivery. Respective questionnaire data was used to distinguish three subtypes of wheezing: any wheezing, infectious wheezing, and noninfectious wheezing. Repeated measurements of wheezing at 3, 6, and 12 months were analyzed using generalized estimation equations. Latent transition analysis assessed patterns of infant wheezing development in the first year of life.Results: The prevalence of any wheezing was highest at 12 months (40.1%). The prevalence of infectious wheezing was higher (3 months 23.8%, 6 months 33.5%, 12 months 38.5%) than of noninfectious wheezing (3 months 13.0%, 6 months 14.0%, 12 months 11.1%). About 11-13% of children had both infectious and noninfectious wheezing at 3, 6, and 12 months (3 months 10.7%, 6 months 13.9%, 12 months 13.1%). Children born via Cesarean section have approximately a 70-80% increase in the risk of any wheezing (RR = 1.83, 95% CI 1.29-2.60) and of infectious wheezing (RR = 1.72, 95% CI 1.18-2.50).Conclusions: Analyses of infectious and noninfectious wheezing subtypes suggests that children born by Cesarean sections may be more susceptible to infectious wheezing, warranting investigations into microbial factors of infectious wheezing. No significant associations were found between prenatal antibiotic exposure and wheezing types.

Impaired Respiratory Function in Women With PCOS Compared With Matched Controls From a Population-Based Study

CONTEXT

Increased prevalence of asthma has been reported from epidemiological studies in women with polycystic ovary syndrome (PCOS).

OBJECTIVE

To investigate respiratory function in women with PCOS compared with controls in a clinical setting.

DESIGN

An 8-year clinical follow-up study including self-reported asthma diagnoses and spirometry of women with PCOS randomized to metformin or placebo during pregnancy in the original studies (the Pilot and the PregMet-study), compared with matched controls from a population-based cohort study (The HUNT Study).

SETTING

Secondary and tertiary care centers.

PARTICIPANTS

A total of 145 women with PCOS (54% of original cohort) were matched 1:3 to controls, on gender, age, and smoking-status.

MAIN OUTCOMES AND MEASURES

Self-reported doctor-diagnosed asthma (DDA), percentage of predicted forced expiratory volume in the first second of expiration (FEV1 % predicted), percentage of predicted forced vital capacity (FVC % predicted).

RESULTS

Women with PCOS reported more DDA compared with controls (19% vs 9%; P < 0.01). Spirometry indicated a combined obstructive (FEV1 % predicted, 93.7 vs 102.0; P < 0.01) and restrictive (FVC % predicted, 94.5 vs 103.7; P < 0.01) respiratory impairment in PCOS compared with controls. Metformin in pregnancy did not affect respiratory function at follow-up.

CONCLUSION

Women with PCOS reported higher prevalence of DDA compared with controls matched for age and smoking status. In addition, respiratory function was decreased, with both obstructive and restrictive components. Further insight to the underlying pathogenesis of these observations is needed.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: The PregMet study: NCT00159536. The Pilot study: NCT03259919.

Transforming growth factor beta in human milk and allergic outcomes in children: A systematic review

BACKGROUND

Human milk (HM) transforming growth factor beta (TGF-β) is critical for inflammation regulation and oral tolerance promotion. Previous reports suggested that variations in HM TGF-β levels are associated with allergic outcomes.

OBJECTIVE

We undertook a systematic review (PROSPERO 2017 CRD42017069920) to reassess the evidence on the relationships between HM TGF-β and allergic outcomes in children.

METHODS

Electronic bibliographic databases (MEDLINE, EMBASE and Cochrane Library) were systematically searched. Two independent reviewers screened reference lists, extracted the data and assessed risk of bias using the National Institute for Clinical Excellence methodological checklist.

RESULTS

A total of 21 studies were identified. Sixteen studies assessed relationships between HM TGF-β and risk of eczema; 14, allergic sensitization; nine, wheezing/asthma; six, food allergy; three, allergic rhinitis/conjunctivitis. Five cohorts (5/18, 28%) reported a protective effect of TGF-β1, while 3 (3/10, 30%) suggested increased risk of allergic outcomes development and 1 (1/10, 10%), a protective effect of TGF-β2 on eczema. Meta-analysis was not possible due to significant heterogeneity in methodology, age of outcome assessment and differing statistical approaches. 71% (15/21) of studies carried a high risk of bias.

CONCLUSION AND CLINICAL RELEVANCE

In contrast with previous findings, we did not find strong evidence of associations between HM TGF-β and allergic outcomes. Differences in studies' methodology and outcomes do not allow unconditional rejection or acceptance of the hypothesis that HM TGF-β influences the risk of allergy development. Future studies on diverse populations employing standardized methods, accurate phenotyping of outcomes and evaluation of the effect of TGF-β in combination with other HM immune markers, microbiome and oligosaccharides are required.

Smoke Exposure, Cytokine Levels, and Asthma Visits in Children Hospitalized for Bronchiolitis

BACKGROUND AND OBJECTIVE

To determine if cigarette smoke exposure, marijuana smoke exposure, or cytokine levels at admission to the hospital for bronchiolitis are associated with follow-up visits for asthma.

METHODS

We enrolled a cohort of children aged 31 days to 2 years who were hospitalized with bronchiolitis from January 2013 to April 2014. Data included the results of a baseline survey about children's health and demographics, nasal wash samples, the results of a 6-month postdischarge follow-up survey, and a chart review. Nasal wash samples were tested for interleukin (IL)-6, IL-13, and tumor necrosis factor α (TNF-α); values were categorized for analysis. χ2, Fisher's exact, and Wilcoxon rank tests were done to test bivariable differences; all analyses were done using SAS.

RESULTS

We approached 180 families for enrollment; 99 consented to participate, and 74% of these completed follow-up surveys. Half of those with high levels of IL-13 had follow-up visits for asthma, whereas only 4.2% of those with low levels had follow-up visits for asthma (P = .02). Marijuana exposure was reported for 12.5% (n = 7) of study participants. There was a significant association between marijuana exposure and TNF-α levels (P = .03).

CONCLUSIONS

Our study revealed an association between IL-13 and follow-up visits for asthma in children who were hospitalized with bronchiolitis. We found an association between family-reported marijuana smoke exposure and detectable but lower levels of TNF-α. Further research is needed to study these relationships.

Informing randomized clinical trials of respiratory syncytial virus vaccination during pregnancy to prevent recurrent childhood wheezing: A sample size analysis

BACKGROUND

Early RSV illness is associated with wheeze-associated disorders in childhood. Candidate respiratory syncytial virus (RSV) vaccines may prevent acute RSV illness in infants. We investigated the feasibility of maternal RSV vaccine trials to demonstrate reductions in recurrent childhood wheezing in general paediatric populations.

METHODS

We calculated vaccine trial effect sizes that depended on vaccine efficacy, allocation ratio, rate of early severe RSV illness, risk of recurrent wheezing at age 3, and increased risk of RSV infection on recurrent wheezing. Model inputs came from systematic reviews and meta-analyses. For each combination of inputs, we estimated the sample size required to detect the effect of vaccination on recurrent wheezing.

RESULTS

There were 81 scenarios with 1:1 allocation ratio. Risk ratios between vaccination and recurrent wheezing ranged from 0.9 to 1.0 for 70% of the scenarios. Among the 57 more plausible scenarios, the lowest sample size required to detect significant reductions in recurrent wheezing was 6196 mother-infant pairs per trial arm; however, 75% and 47% of plausible scenarios required >31,060 and >100,000 mother-infant pairs per trial arm, respectively. Studies with asthma endpoints at age 5 will likely need to be larger.

DISCUSSION

Clinical efficacy trials of candidate maternal RSV vaccines undertaken for licensure are unlikely to demonstrate an effect on recurrent wheezing illness due to the large sample sizes likely needed to demonstrate a significant effect. Further efforts are needed to plan for alternative study designs to estimate the impact of maternal RSV vaccine programs on recurrent childhood wheezing in general populations.

Sex discordance in asthma and wheeze prevalence in two longitudinal cohorts

Sex discordance in asthma prevalence has been previously reported, with higher prevalence in males before puberty, and in females after puberty; the adolescent "switch". However, cross-sectional studies have suggested a narrowing of this discordance in recent decades. We used a combination of cross-sectional and longitudinal modelling to examine sex differences in asthma, wheeze and longitudinal wheezing phenotypes in two UK birth cohorts, the Avon Longitudinal Study of Parents and Children (ALSPAC; born 1991-92 with data from age 0-18 years) and the Millennium Cohort Study (MCS; born 2000-02 with data from age 3-10 years). We derived measures of asthma and wheeze from questionnaires completed by mothers and cohort children. Previously-derived ALSPAC wheezing phenotype models were applied to MCS. Males had a higher prevalence of asthma at 10.7 years in ALSPAC (OR 1.45 95%CI: 1.26, 1.66 n = 7778 for current asthma) and MCS (OR 1.42 95%CI: 1.29, 1.56 n = 6726 for asthma ever) compared to females, decreasing in ALSPAC after puberty (OR 0.94 95%CI: 0.79, 1.11 n = 5023 for current asthma at 16.5 years). In longitudinal models using restricted cubic splines, males had a clear excess for asthma in the last 12 months and wheeze in the last 12 months up until 16.5 years of age in ALSPAC. Males had an increased risk of all derived longitudinal wheezing phenotypes in MCS when compared to never wheeze and no evidence of being at lower risk of late wheeze when compared to early wheeze. By comparing data in two large, contemporary cohorts we have shown the persistence of sex discordance in childhood asthma, with no evidence that the sex discordance is narrowing in recent cohorts.

Sleep disorders and allergic diseases in Chinese toddlers

OBJECTIVE

Optimal sleep is important for child growth, development, and immune function. We aimed to explore whether sleep disorders were associated with the risk of allergic diseases in Chinese toddlers.

METHODS

This study included 566 children (aged 23.9 ± 0.7 months; 51.1% boys) in Shanghai, China. Sleep parameters (total sleep time, sleep onset latency, nocturnal awaking and snoring) were assessed by an expanded version of the Brief Infant Sleep Questionnaire (BISQ-expanded). Information on four allergic diseases (wheeze, eczema, food allergy, and allergic rhinitis) in the past year was collected via standard questionnaire and judged by pediatricians. We used logistic regression to calculate odds ratios (ORs) and their 95% confidence intervals (CIs) for having any/and each of the four allergic diseases, based on sleep parameters, adjusting for children's age and gender, mode of delivery, any breastfeeding duration, children's body mass index (BMI), children's exposure to passive smoking, maternal education, family income, family allergic history, and children's antibiotic use.

RESULTS

There were 23.3% of children with at least one of the four allergic diseases. Snoring was significantly associated with increased odds of having any allergy (adjusted OR = 1.95; 95% CI: 1.17, 3.26), eczema (OR = 1.83, 95% CI: 1.03, 3.23) and food allergy (OR = 4.31, 95% CI: 1.23, 15.14), after adjustment for potential confounders. Nocturnal awaking ≥2 times per night was associated with higher risk of food allergy (OR = 3.92, 95% CI: 1.00, 15.35) and wheeze (OR = 6.16, 95% CI: 1.28, 29.74).

CONCLUSION

In this study, presence of certain sleep disorders was associated with higher risk of having allergic diseases in Chinese toddlers.

Association of Acetaminophen and Ibuprofen Use With Wheezing in Children With Acute Febrile Illness

BACKGROUND

Many infants and children receive acetaminophen and/or ibuprofen during febrile illness. Previously, some studies have linked acetaminophen and ibuprofen use to wheezing and exacerbation of asthma symptoms in infants and children.

OBJECTIVE

To assess whether acetaminophen or ibuprofen use are associated with wheezing in children presenting to the emergency department (ED) with febrile illness.

METHODS

This was a cross-sectional study of children who presented with fever to the pediatric ED between 2009 and 2013. The data were collected from questionnaires and from the children's medical files. Patients with wheezing in the ED were compared with nonwheezing patients. Associations between medication use and wheezing were assessed using univariate and multivariate analyses. The multivariate analysis adjusted for potential confounding variables (ie, age, atopic dermatitis, allergies, smoking, antibiotics use, etc) via propensity scores.

RESULTS

During the study period, 534 children admitted to the ED met our inclusion criteria, of whom 347 (65%) were included in the study. The use of acetaminophen was similar in children diagnosed with wheezing compared with those without wheezing (n = 39, 81.3%, vs n = 229, 82.7%, respectively). Ibuprofen use was significantly lower in children diagnosed with wheezing (n = 22, 52.4%, vs n = 168, 69.4%, respectively). In multivariate analysis, acetaminophen was not associated with a higher rate of wheezing during acute febrile illness (adjusted odds ratio [OR] = 0.76, 95% CI = 0.24- 2.39), whereas ibuprofen was associated with a lower risk of wheezing (adjusted OR = 0.36, 95% CI = 0.13-0.96).

CONCLUSIONS

Our study suggests that acetaminophen and ibuprofen are not associated with increased risk for wheezing during acute febrile illness.

Growth, Nutritional Status, and Pulmonary Function in Children with Chronic Recurrent Bronchitis

Bronchitis is a common health problem in children. Frequent bronchitis in infancy increases the risk of developing chronic respiratory diseases. The aim of the study was to assess the level of growth and the nutritional status in children and youths with special regard to the level of body fatness assessed by measuring skin-fold thickness. Relationships between somatic development, pulmonary function and the course of the disease were also explored. The study was carried out using anthropometric and spirometric measurements and also information on the severity and course of the disease in 141 children with chronic or recurrent bronchitis. All of the subjects were patients of the Pulmonary Medicine and Allergology Center in Karpacz, Poland. The mean body height did not differ significantly between the children examined and their healthy peers. However, the infection-prone children had excessive body fatness and muscle mass deficiency. The increased level of subcutaneous adipose tissue occurred especially in children with short duration of the disease, i.e. a maximum of 1 year. The functional lung parameters were generally normal. The presence of atopic diseases such as allergic rhinitis or atopic dermatitis did not impair the course of the children's somatic development. Also, long-term disease or the presence of additional allergic diseases did not impair lung function in the examined children. Taking appropriate preventive measures is recommended to achieve and maintain normal body weight in children who receive therapy due to bronchitis.

Motives for Smoking Cessation are Associated with Stage of Readiness to Quit Smoking and Sociodemographics among German Industrial Employees

Purpose.

To test the relationships among particular motives for smoking cessation, stage of readiness to quit (preparation or contemplation), and sociodemographic characteristics.

Design.

A cross-sectional study to examine attitudes toward and use of health promotion at the worksite, using a self-administered questionnaire.

Setting.

Two German metal companies.

Subjects.

Of 1641 responding employees (response rate 65% in company A and 44% in company B), 360 smokers who intended to quit immediately (n = 105) or in the near future (n = 255) were analyzed.

Measures.

The questionnaire comprised of sociodemographic characteristics, smoking behavior, smoking history, readiness to quit smoking, motives to quit, such as coworkers' complaints and health-related or financial concerns. Chi-squared tests and multiple logistic regression analyses were performed.

Results.

Health-related reasons (94%) predominated financial (27%) or image-related (14%) reasons for smoking cessation. Participants in the cessation preparation group were more likely to report an awareness of being addicted (79.6% vs. 58.2%; p < .001) and the negative public image (22.5% vs. 11.6%; p < .01) as reasons for quitting compared with those in the contemplation group. In multivariable regression models, the motives for smoking cessation, including reduced performance, family's and coworkers' complaints, pregnancy/children, and negative public image, but not health-related and financial concerns, differed significantly by gender, age, marital status, education, and occupational status.

Conclusions.

Motives for smoking cessation vary according to the individual's level of readiness to quit and sociodemographic background.

Spatial clusters of child lower respiratory illnesses associated with community-level risk factors

Identifying geographic areas with increased incidence of disease may elucidate community-level risk factors for intervention development. Lower respiratory illnesses (LRIs) are the leading cause of death in children and are associated with other morbidities. We assessed geographic clustering of LRIs and evaluated if these spatial patterns and associated risk factors differed by phenotype. Participants enrolled at birth in the Tucson Children's Respiratory Study were followed through age three for physician diagnosed LRIs. Spatial clustering analysis, based upon each participant's birth address, was performed for four LRI phenotypes. We conducted principal component analysis at the census tract level to generate indices for lower socioeconomic status (SES), poorer housing conditions, and increased air pollution. Enrollment addresses were mapped for 812 subjects, of whom 58.4%, 33.5%, 34.2%, and 23.4% had any LRI, a wheezing LRI, a viral LRI, and a respiratory syncytial virus (RSV) LRI, respectively. Patterns of spatial clustering and associated risk factors differed by LRI phenotype. Multivariable regression analyses showed that wheezing LRI clusters were associated with increased air pollution (OR = 1.18, P = 0.01). Being in a viral cluster was associated with poorer housing conditions (OR = 1.28, P = 0.01), while being in a RSV cluster was associated with increased air pollution (OR = 1.14, P = 0.006), poorer housing conditions (OR = 1.54, P = 0.003), and higher SES (OR = 0.77, P = 0.001). Our use of social and environmental indices allowed us to identify broad contextual factors that may contribute to increased incidence of LRIs in specific geographic regions. To reduce LRI incidence, multifaceted interventions should be developed at the community level. Pediatr Pulmonol. 2016;51:633-642. © 2015 Wiley Periodicals, Inc.

Infant Infections and Respiratory Symptoms in Relation to in Utero Arsenic Exposure in a U.S. Cohort

BACKGROUND

Arsenic has been linked to disrupted immune function and greater infection susceptibility in highly exposed populations. Well arsenic levels above the U.S. EPA limit occur in our U.S. study area and are of particular concern for pregnant women and infants.

OBJECTIVES

We investigated whether in utero arsenic exposure affects the risk of infections and respiratory symptoms over the first year of life.

METHODS

We prospectively obtained information on infant infections and symptoms, including their duration and treatment (n = 412) at 4, 8, and 12 months using a parental telephone survey. Using generalized estimating equation models adjusted for potential confounders, we evaluated the association between maternal pregnancy urinary arsenic and infant infections and symptoms over the first year.

RESULTS

Each doubling of maternal urinary arsenic was related to increases in the total number of infections requiring prescription medication in the first year [relative risk (RR) = 1.1; 95% CI: 1.0, 1.2]. Urinary arsenic was related specifically to respiratory symptoms (difficulty breathing, wheezing, and cough) lasting ≥ 2 days or requiring prescription medication (RR = 1.1; 95% CI: 1.0, 1.2; and RR = 1.2; 95% CI: 1.0, 1.5, respectively), and wheezing lasting ≥ 2 days, resulting in a doctor visit or prescription medication treatment (RR = 1.3; 95% CI: 1.0, 1.7; RR = 1.3; 95% CI: 1.0, 1.8, and RR = 1.5; 95% CI: 1.0, 2.2, respectively). Associations also were observed with diarrhea (RR = 1.4; 95% CI: 1.1, 1.9) and fever resulting in a doctor visit (RR = 1.2; 95% CI: 1.0, 1.5).

CONCLUSIONS

In utero arsenic exposure was associated with a higher risk of infection during the first year of life in our study population, particularly infections requiring medical treatment, and with diarrhea and respiratory symptoms.

CITATION

Farzan SF, Li Z, Korrick SA, Spiegelman D, Enelow R, Nadeau K, Baker E, Karagas MR. 2016. Infant infections and respiratory symptoms in relation to in utero arsenic exposure in a U.S.

COHORT

Environ Health Perspect 124:840-847; http://dx.doi.org/10.1289/ehp.1409282.

Alcohol Intake During Pregnancy and Offspring's Atopic Eczema Risk

BACKGROUND

Although alcohol consumption has been suggested to have an effect on the immune system, it is unknown whether alcohol consumption has a role in developing allergic diseases. We aimed to examine the associations of total alcohol intake during pregnancy with the risks of childhood asthma and atopic eczema in a birth cohort in Japan.

METHODS

Pregnant women were recruited at a maternal clinic from May 2000 to October 2001. The children who were born to these mothers were followed until November 2007. Total alcohol intake, including alcohol as a cooking ingredient, was assessed using 5-day dietary records. Mother reports of physician-diagnosed asthma and atopic eczema were annually obtained from the questionnaires. Asthma assessed by the American Thoracic Society Division of Lung Diseases questionnaire and atopic eczema assessed by International Study of Asthma and Allergies in Childhood questions were also obtained in 2007. A total of 350 children participated in the follow-up survey.

RESULTS

Maternal total alcohol intake during pregnancy was associated with increased risks of atopic eczema before age 3. The positive association with atopic eczema was also observed when it was defined as before age 5. In the high versus the low tertile of maternal total alcohol intake, the estimated hazard ratios (HRs) of child's eczema were 1.90 (95% CI: 0.96 to 3.76) before age 3 and 1.74 (95% CI: 0.93 to 3.24) before age 5, respectively. The estimated HRs of child's asthma before age 3 was 1.61 (95% CI: 0.70 to 3.69) in the high versus the low of maternal total alcohol intake and 2.11 (95% CI: 0.93 to 4.81) among children having drinking mothers versus nondrinking mothers in pregnancy, although maternal alcohol intake during pregnancy was not significantly associated with the risk of asthma before age 5.

CONCLUSIONS

Alcohol consumption during pregnancy might have an effect on developing atopic eczema in offspring.

Prenatal maternal stress and atopic diseases in the child: a systematic review of observational human studies

BACKGROUND

A growing number of studies suggest that maternal stress during pregnancy promotes atopic disorders in the offspring. This is the first systematic review to address prenatal maternal stress (PNMS) and the subsequent risk of atopy-related outcomes in the child.

METHODS

The review was performed in accordance to the PRISMA criteria. We searched and selected studies in PubMed, Scopus, Embase and PsychINFO until November 2014.

RESULTS

Sixteen (with 25 analyses) of 426 identified articles met the review criteria. Five main PNMS exposures (negative life events, anxiety/depression, bereavement, distress and job strain) and five main atopic outcomes (asthma, wheeze, atopic dermatitis, allergic rhinitis and IgE) were assessed across the studies. Overall, 21 of the 25 analyses suggested a positive association between PNMS and atopic outcomes. Of the 11 exposure-response analyses reported, six found statistically significant trends.

CONCLUSION

This systematic review suggests a relationship between maternal stress during pregnancy and atopic disorders in the child. However, the existing studies are of diverse quality. The wide definitions of often self-reported stress exposures imply a substantial risk for information bias and false-positive results. Research comparing objective and subjective measures of PNMS exposure as well as objective measures for atopic outcome is needed.

The evaluation of risk factors for recurrent hospitalizations resulting from wheezing attacks in preschool children

BACKGROUND

We aimed to evaluate the risk factors in preschool children admitted to inpatient services with a diagnosis of recurrent attacks of wheezing.

METHOD

The medical files of 44 preschool children with 2 or more recurrent hospitalizations resulting from wheezing between November 2011 and January 2012 were retrospectively investigated.

RESULTS

There were 28 males (64 %) and 16 females. The median age was 14 months (2.0-50). The median numbers of previous wheezing attacks and hospitalizations were 4 (2-10) and 2 (2-8), respectively. Fourteen patients (32 %) had been treated for gastroesophageal reflux (GER). The previous and recent hospital evaluations were investigated. Bronchopulmonary dysplasia and anemia were significantly more common in patients with 3 or more hospitalizations for wheezing than in those with 2 hospitalizations (p = 0.010 and p < 0.001, respectively). A review of the cases with 3 or more hospitalizations revealed that a history of GER and anemia were significant risk factors.

CONCLUSION

Anemia and GER are risk factors for recurrent hospitalizations resulting from wheezing and should be treated. If the history and physical examination suggest asthma, inhaler therapy treatment should be administered, with other investigations planned for patients who do not respond to treatment as expected.

Population Health Considerations for Pediatric Asthma: Findings from the 2011-2012 California Health Interview Survey

Childhood asthma is a prevalent and costly chronic condition. Optimal management enables secondary and tertiary prevention. The goal was to identify population health considerations for pediatric asthma in California to inform the development of quality improvement interventions. California Health Interview Survey 2011-2012 is a random-digit dial telephone survey conducted in 5 languages. It includes 44,000 households from all 58 counties in California. This study assessed factors related to symptom control and health care use in children ages 2-11 years with asthma. An estimated 492,385 (9.6%) of children in California currently have asthma. Urban and rural residents face comparable asthma disease burdens. School-age male children as well as Asian and African American children are disproportionately affected. Asthma causes significant morbidity, with poorer health status, high utilization of emergency care, and the need for daily medication use. Only 38% of children with asthma have a recent asthma management plan. Half of all children with asthma did not receive influenza immunization in the past year, although this reflects the overall low rate of influenza vaccination. Parents of children with asthma frequently utilize the Internet for health information and communication with their child's health care provider. Children with asthma in California face several population-level challenges, including poor health status, low influenza vaccination rates, high use of emergency care, and suboptimal use of health literacy tools. Focusing on improved care coordination and preventive care for high-risk groups is especially urgent given the expansion of public health insurance and impending shortages in the primary care workforce. (Population Health Management 2016;19:145-151).

Operational definitions of asthma in recent epidemiological studies are inconsistent

OBJECTIVE

The best combination of questions to define asthma in epidemiological asthma studies is not known. We summarized the operational definitions of asthma used in prevalence studies and empirically assess how asthma prevalence estimates vary depending on the definition used.

METHODS

We searched the Thomson Reuters ISI Web of knowledge and included (1) cross-sectional studies (2) on asthma prevalence (3) conducted in the general population and (4) containing an explicit definition of asthma. The search was limited to the 100 most-cited papers or published since January 2010. For each paper, we recorded the asthma definition used and other variables. Then we applied the definitions to the data of the Portuguese National Asthma survey (INAsma) and of the 2005-2006 National Health and Nutrition Examination Survey (NHANES) computing asthma prevalence estimates for the different definitions.

RESULTS

Of 1738 papers retrieved, 117 were included for analysis. Lifetime asthma, diagnosed asthma and current asthma were defined in 8, 12 and 29 different ways, respectively. By applying definitions of current asthma on INAsma and NHANES data, the prevalence ranged between 5.3%-24.4% and 1.1%-17.2%, respectively.

CONCLUSIONS

There is considerable heterogeneity in the definitions of asthma used in epidemiological studies leading to highly variable estimates of asthma prevalence. Studies to inform a standardized operational definition are needed. Meanwhile, we propose a set of questions to be reported when defining asthma in epidemiological studies.

In utero arsenic exposure and infant infection in a United States cohort: a prospective study

Arsenic (As), a ubiquitous environmental toxicant, has recently been linked to disrupted immune function and enhanced infection susceptibility in highly exposed populations. In drinking water, as levels above the EPA maximum contaminant level occur in our US study area and are a particular health concern for pregnant women and infants. As a part of the New Hampshire Birth Cohort Study, we investigated whether in utero exposure to As affects risk of infant infections. We prospectively obtained information on 4-month-old infants (n=214) using a parental telephone survey on infant infections and symptoms, including respiratory infections, diarrhea and specific illnesses, as well as the duration and severity of infections. Using logistic regression and Poisson models, we evaluated the association between maternal urinary As during pregnancy and infection risks adjusted for potentially confounding factors. Maternal urinary As concentrations were related to total number of infections requiring a physician visit (relative risk (RR) per one-fold increase in As in urine=1.5; 95% confidence interval (CI)=1.0, 2.1) or prescription medication (RR=1.6; 95% CI=1.1, 2.4), as well as lower respiratory infections treated with prescription medication (RR=3.3; 95% CI=1.2, 9.0). Associations were observed with respiratory symptoms (RR=4.0; 95% CI=1.0, 15.8), upper respiratory infections (RR=1.6; 95% CI=1.0, 2.5), and colds treated with prescription medication (RR=2.3; 95% CI=1.0, 5.2). Our results provide initial evidence that in utero As exposure may be related to infant infection and infection severity and provide insight into the early life impacts of fetal As exposure.

Breastfeeding as a modifier of the respiratory effects of air pollution in children

BACKGROUND

Breastfeeding and air pollution are both important factors for respiratory symptoms and asthma in children. Few studies have examined possible interaction between them on respiratory outcomes.

METHODS

We studied 31,049 Chinese children, ages 2-14 years old, from 25 elementary schools and 50 kindergartens in the Seven Northeastern Cities during 2008-2009. Parents or guardians completed questionnaires about the children's histories of respiratory conditions, risk factors, and feeding methods. Three-year average concentrations of particles with an aerodynamic diameter ≤ 10 µm, sulfur dioxide, nitrogen dioxides, and ozone were calculated from monitoring stations in 25 study districts. We used two-level logistic regressions to examine the effects of exposure, controlling for covariates.

RESULTS

Association of air pollution with childhood respiratory conditions was modified by breastfeeding. Compared with children who had been breastfed, those who were not exhibited consistently stronger effects of air pollution. Among non-breastfed children, odds ratios (ORs) per 10 µg/m increase in nitrogen dioxide were 1.40 (95% confidence interval = 1.19-1.64) for cough, 1.41 (1.16-1.71) for phlegm, 1.17 (1.00-1.36) for current wheeze, and 1.25 (1.07-1.46) for doctor-diagnosed asthma. For breastfed children, the ORs were 1.25 (1.09-1.43) for cough, 1.15 (0.99-1.34) for phlegm, 0.97 (0.87-1.08) for current wheeze, and 1.17 (1.05-1.32) for doctor-diagnosed asthma. Breastfeeding was more protective among younger children. Breastfeeding was also associated with reduced effects of passive smoke exposure in children.

CONCLUSION

Breastfeeding is associated with smaller associations between air pollution and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of pollutants.

Effects of geohelminth infection and age on the associations between allergen-specific IgE, skin test reactivity and wheeze: a case-control study

Background

Most childhood asthma in poor populations in Latin America is not associated with aeroallergen sensitization, an observation that could be explained by the attenuation of atopy by chronic helminth infections or effects of age.

Objective

To explore the effects of geohelminth infections and age on atopy, wheeze, and the association between atopy and wheeze.

Methods

A case-control study was done in 376 subjects (149 cases and 227 controls) aged 7–19 years living in rural communities in Ecuador. Wheeze cases, identified from a large cross-sectional survey, had recent wheeze and controls were a random sample of those without wheeze. Atopy was measured by the presence of allergen-specific IgE (asIgE) and skin prick test (SPT) responses to house dust mite and cockroach. Geohelminth infections were measured in stools and anti-Ascaris IgE in plasma.

Results

The fraction of recent wheeze attributable to anti-Ascaris IgE was 45.9%, while those for SPT and asIgE were 10.0% and 10.5% respectively. The association between atopy and wheeze was greater in adolescents than children. Although Anti-Ascaris IgE was strongly associated with wheeze (adj. OR 2.24 (95% CI 1.33–3.78, P = 0.003) and with asIgE (adj. OR 5.34, 95% CI 2.49–11.45, P < 0.001), the association with wheeze was independent of asIgE. There was some evidence that the association between atopy and wheeze was greater in uninfected subjects compared with those with active geohelminth infections.

Conclusions and clinical relevance

Atopy to house dust mite and cockroach explained few wheeze cases in our study population, while the presence of anti-Ascaris IgE was an important risk factor. Our data provided only limited evidence that active geohelminth infections attenuated the association between atopy and wheeze in endemic areas or that age modified this association. The role of allergic sensitization to Ascaris in the development of wheeze, independent of atopy, requires further investigation.

Association of breastfeeding with asthma in young Aboriginal children in Canada

BACKGROUND

Few studies have investigated the factors associated with asthma in young Aboriginal children.

OBJECTIVE

To characterize the association of demographic, environmental and early life factors with asthma in young Aboriginal children in Canada.

METHODS

The 2006 Aboriginal Children's Survey was conducted among off-reserve Aboriginal children zero to six years of age to obtain information on Aboriginal children's development and well-being. The prevalence of asthma in Aboriginal children was obtained from the parental report of asthma as diagnosed by a health care professional.

RESULTS

The prevalence of reported asthma among off-reserve Aboriginal children zero to six years of age (n=14,170) was 9.4%. Asthma prevalence in both exclusively breastfed children (6.8%) and ever but not exclusively breastfed children (9.0%) was significantly lower than that in nonbreastfed children (11.0%). In the multiple logistic regression analysis, exclusive breastfeeding was protective of asthma compared with nonbreastfeeding (OR 0.59 [95% CI 0.44 to 0.78]). Older age groups, male sex, having two or more older siblings, low birth weight, day care attendance and ear infection were significant risk factors for asthma.

CONCLUSIONS

The prevalence of asthma among young Aboriginal children zero to six years of age living off reserve was slightly lower than that reported for all other Canadian children. Breastfeeding, especially exclusively breastfeeding, was protective of asthma in Aboriginal children, which is consistent with what has been observed in non-Aboriginal children in Canada. Public health interventions intended for reducing asthma incidence in young Aboriginal children should include breastfeeding promotion programs.

Allergy and acute leukaemia in children with Down syndrome: a population study. Report from the Mexican inter-institutional group for the identification of the causes of childhood leukaemia

BACKGROUND

Allergies have been described as protective factors against the development of childhood acute leukaemia (AL). Our objective was to investigate the associations between allergy history and the development of AL and acute lymphoblastic leukaemia (ALL) in children with Down syndrome (DS).

METHODS

A case-control study was performed in Mexico City. The cases (n=97) were diagnosed at nine public hospitals, and the controls (n=222) were recruited at institutions for children with DS. Odds ratios (OR) were calculated.

RESULTS

Asthma was positively associated with AL development (OR=4.18; 95% confidence interval (CI): 1.47-11.87), whereas skin allergies were negatively associated (OR=0.42; 95% CI: 0.20-0.91).

CONCLUSION

Our findings suggest that allergies and AL in children with DS share biological and immune mechanisms. To our knowledge, this is the first study reporting associations between allergies and AL in children with DS.

Maternal intestinal flora and wheeze in early childhood

BACKGROUND

Increasing evidence links altered intestinal flora in infancy to eczema and asthma. No studies have investigated the influence of maternal intestinal flora on wheezing and eczema in early childhood.

OBJECTIVE

To investigate the link between maternal intestinal flora during pregnancy and development of wheeze and eczema in infancy.

METHODS

A total of 60 pregnant women from the Boston area gave stool samples during the third trimester of their pregnancy and answered questions during pregnancy about their own health, and about their children's health when the child was 2 and 6 months of age. Quantitative culture was performed on stool samples and measured in log(10)colony-forming units (CFU)/gram stool. Primary outcomes included infant wheeze and eczema in the first 6 months of life. Atopic wheeze, defined as wheeze and eczema, was analysed as a secondary outcome.

RESULTS

In multivariate models adjusted for breastfeeding, day care attendance and maternal atopy, higher counts of maternal total aerobes (TA) and enterococci (E) were associated with increased risk of infant wheeze (TA: OR 2.32 for 1 log increase in CFU/g stool [95% CI 1.22, 4.42]; E: OR 1.57 [95% CI 1.06, 2.31]). No organisms were associated with either eczema or atopic wheeze.

CONCLUSIONS AND CLINICAL RELEVANCE

In our cohort, higher maternal total aerobes and enterococci were related to increased risk of infant wheeze. Maternal intestinal flora may be an important environmental exposure in early immune system development.

Ambient pollen concentrations and emergency department visits for asthma and wheeze

BACKGROUND

Previous studies report associations between aeroallergen exposure and asthma exacerbations. Aeroallergen burdens and asthma prevalence are increasing worldwide and are projected to increase further with climate change, highlighting the importance of understanding population-level relationships between ambient pollen concentrations and asthma.

OBJECTIVE

We sought to examine short-term associations between ambient concentrations of various pollen taxa and emergency department (ED) visits for asthma and wheeze in the Atlanta metropolitan area between 1993 and 2004.

METHODS

We assessed associations between the 3-day moving average (lag 0-1-2) of Betulaceae (except Alnus species), Cupressaceae, Quercus species, Pinaceae (except Tsuga species), Poaceae, and Ambrosia species pollen concentrations and daily asthma and wheeze ED visit counts, controlling for covarying pollen taxa and ambient pollutant concentrations.

RESULTS

We observed a 2% to 3% increase in asthma- and wheeze-related ED visits per SD increase in Quercus species and Poaceae pollen and a 10% to 15% increased risk on days with the highest concentrations (comparing the top 5% of days with the lowest 50% of days). An SD increase in Cupressaceae concentrations was associated with a 1% decrease in ED visits. The association for Quercus species pollen was strongest for children aged 5 to 17 years. Effects of Ambrosia species pollen on asthma exacerbations were difficult to assess in this large-scale temporal analysis because of possible confounding by the steep increase in circulating rhinoviruses every September.

CONCLUSION

Poaceae and Quercus species pollen contribute to asthma morbidity in Atlanta. Altered Quercus species and Poaceae pollen production caused by climate change could affect allergen-induced asthma morbidity in the southeastern United States.

[Prevalence of wheezing and associated risk factors among infants in Recife, Pernambuco State, Brazil]

The aim of this study was to verify the prevalence of wheezing in infants (< 1 year of age) in Recife, Pernambuco State, Brazil, and to identify associated risk factors.

SAMPLE AND METHODS

the study was performed according to the protocol of the International Study of Wheezing in Infants (EISL) in children ranging from 12 to 15 months of age. The sample was analyzed for presence or absence of wheezing. A total of 1,071 parents of children ranging from 12 to 15 months of age were interviewed. Prevalence of wheezing in the first year of life was 43%, with no difference between the sexes. Wheezing in the first year of life was associated with pneumonia, family history of asthma, more than nine episodes of upper airway infection, and the first cold before six months of age (p < 0.001). Prevalence of wheezing in the first year of life was high in Recife. Early onset (and high number) of colds, family history of asthma, and pneumonia were associated with wheezing in these children.

Predicting the long-term course of asthma in wheezing infants is still a challenge

Background. In recurrent wheezing infants, it is important to identify those likely to remain asthmatic in order to propose appropriate long-term management. Objective. To establish predictive factors for persistent asthma at adolescence in a population of recurrent wheezing infants. Methods. Retrospective study of 227 infants. Inclusion criteria were age under 36 months, a history of at least three wheezing episodes assessed via a doctor-led ISAAC questionnaire and a standardized allergy testing programme. At 13 years, active asthma was assessed by questionnaire. Results. Risk factors for asthma persisting into adolescence were allergic sensitization to multiple airborne allergens (OR 4.6, CI-95% (1.9–11.2) P = 0.001), initial atopic dermatitis (OR 3.4, CI-95% (1.9–6.3) P < 0.001), severe recurrent wheezing (OR 2.3, CI-95% (1.3–4.2) P = 0.007), and hypereosinophilia ≥470/mm³ (OR 2.2, CI-95% (1.07–4.7) P = 0.033). Conclusion. While it is still difficult to predict the long-term course of asthma, atopy remains the major risk factor for persistent asthma.

Vaccination coverage and risk factors for incomplete vaccination in children with recurrent wheeze

AIM

To determine the possible impact of recurrent wheeze on immunisation status in the first three years of life.

METHOD

A cross-sectional case control study of 288 children less than three years of age with a history of recurrent wheezing, hospitalised at a single centre for wheeze; and a control group of 190 children with no prior history of wheezing. Vaccination charts of all children were analysed according to the National Immunisation Schedule. Additionally, some associated data were collected through a questionnaire to the parents.

RESULTS

Children with recurrent wheezing during the first three years of life were less likely to be vaccinated against BCG (Bacillus-Calmette-Guerin), hepatitis B, Hib (Haemophilus influenza type B), and MMR (Measles, Mumps, Rubella) (p < 0.001). A significant inverse association was also found between the number of wheezy episodes and the number of vaccine doses received. The odds ratio of incomplete vaccination in children with recurrent wheeze was 10.6 (95% CI, 2.96 to 38.1).

CONCLUSION

Children under three years of age with recurrent wheeze run a high risk of incomplete immunisation. Efforts should be therefore made to insure that such children receive adequate vaccination.

The role of anti-infectives in the treatment of refractory asthma

Refractory asthma not only has a significant effect on quality of life, but also imposes an economic burden on society. Increasing evidence suggests that there is a pathophysiologic interaction between infection and allergic disease in patients with severe or refractory asthma. Therapeutic trials of macrolides and azoles are being utilized in some patients with refractory asthma who fail to respond to standard therapy. In this article we review the definition of refractory asthma and the potential pathophysiologic interactions between infection and allergic disease. Emerging data suggest that microorganisms and their byproducts may be a therapeutic target in the therapy of patients with severe or refractory asthma.

Parental psychosocial stress and asthma morbidity in Puerto Rican twins

BACKGROUND

Little is known about paternal psychosocial factors and childhood asthma.

OBJECTIVE

We sought to examine the link between maternal and paternal psychosocial stress and asthma outcomes in young children.

METHODS

Parents of 339 pairs of Puerto Rican twins were interviewed individually about their own psychosocial stress and about asthma in their children at age 1 year and again about their child's asthma at age 3 years. Fathers were asked about symptoms of posttraumatic stress disorder (PTSD), depression, and antisocial behavior. Mothers were asked about depressive symptoms. Outcomes assessed in children included recent asthma symptoms, oral steroid use and hospitalizations for asthma in the prior year, and asthma diagnosis. Generalized estimated equation models were used for the multivariate analysis of parental psychosocial stress and asthma morbidity in childhood.

RESULTS

After multivariable adjustment, paternal PTSD symptoms, depression, and antisocial behavior were each associated with increased asthma symptoms at age 1 year (eg, odds ratio, 1.08 for each 1-point increase in PTSD score; 95% CI, 1.03-1.14). Maternal depressive symptoms were associated with an increased risk of asthma hospitalizations at age 1 year. At age 3 years, maternal depressive symptoms were associated with asthma diagnosis and hospitalizations for asthma (odds ratio for each 1-point increase in symptoms, 1.16; 95% CI, 1.00-1.36). In an analysis combining 1- and 3-year outcomes, paternal depression was associated with oral steroid use, maternal depressive symptoms were associated with asthma hospitalizations and asthma diagnosis, and parental depression was associated with hospitalizations for asthma.

CONCLUSIONS

Both paternal and maternal psychosocial factors can influence asthma morbidity in young Puerto Rican children.

The presence of serum anti-Ascaris lumbricoides IgE antibodies and of Trichuris trichiura infection are risk factors for wheezing and/or atopy in preschool-aged Brazilian children

BACKGROUND

The elucidation of factors that trigger the development of transient wheezing in early childhood may be an important step toward understanding the pathogenesis of asthma and other allergic diseases later in life. Transient wheezing has been mainly attributed to viral infections, although sensitisation to aeroallergens and food allergens may occur at an early age. In developing countries, intestinal helminthic infections have also been associated with allergy or atopy-related disorders.

OBJECTIVE

The aim of this study was to explore the association of Trichuris trichiura and Ascaris lumbricoides infections with wheezing and atopy in early childhood.

STUDY DESIGN

A cross-sectional study using a Portuguese-language ISAAC phase I questionnaire, adapted for preschool-aged children, nested in a cohort study of childhood diarrhoea, was conducted on 682 children. Two faecal samples per child were examined for the presence of intestinal helminthic infection. IgE antibodies against three allergenic preparations (Dermatophagoides pteronyssinus, Blomia tropicalis and common child food), as well as against A. lumbricoides antigens, were measured in a sub-sample of these children, whose parents allowed the procedure. Atopy was defined by the presence of levels of serum IgE antibodies ≥0.35 kU/L against at least one of the three tested allergenic preparations.

RESULTS

Active T. trichiura infection but not A. lumbricoides infection was positively associated with wheezing in the total studied children population [adjusted OR = 2.60; CI = 1.54;4.38] and in the atopic children sub-population [adjusted OR = 3.07; CI = 1.00;9.43]. The association with atopy was also positive and statistically significant only in the brute analysis [OR = 2.13; CI = 1.03;4.40]. Anti-A. lumbricoides IgE antibodies, but not current A. lumbricoides infection, were positively associated with wheezing in atopic children [adjusted OR = 2.01; CI = 1.00;4.50] and in non-atopic children [adjusted OR = 3.07; CI = 1.13;8.35] and it was also associated with atopy [adjusted OR = 7.29; CI = 3.90; 13.4]. On the other hands, reports of wheezing were not significantly associated with atopy.

CONCLUSIONS

These data corroborate previous studies showing that wheezing is predominantly associated with infection in early childhood and shows that anti-A. lumbricoides IgE antibodies, but not active Ascaris infections, are associated with wheezing and atopy. Additionally, the data demonstrate that T. trichiura infection may play a role in the pathogenesis of atopic wheezing in early childhood.

Altered signaling through IL-12 receptor in children with very high serum IgE levels

An alteration of Th1/Th2 homeostasis may lead to diseases in humans. In this study, we investigated whether an impaired IL-12R signaling occurred in children with elevated serum IgE levels divided on the basis of the IgE levels (group A: >2000kU/l; group B: <2000kU/l). We evaluated the integrity of the IL-12R signaling through the analysis of phosphorylation/activation of STAT4, and mRNA expression and membrane assembly of the receptor chains. At a functional level, a proliferative defect of lymphocytes from group A patients was observed. In these patients, an abnormal IL-12R signaling was documented, and this finding was associated with abnormal expression of the IL-12Rbeta2 chain. Our data indicate that in patients with very high IgE levels the generation of Th1 response is impaired, and that this abnormality associates with abnormal IL-12R signaling.

Antenatal steroid therapy for fetal lung maturation and the subsequent risk of childhood asthma: a longitudinal analysis

This study was designed to test the hypothesis that fetal exposure to corticosteroids in the antenatal period is an independent risk factor for the development of asthma in early childhood with little or no effect in later childhood. A population-based cohort study of all pregnant women who resided in Nova Scotia, Canada, and gave birth to a singleton fetus between 1989 and 1998 was undertaken. After a priori specified exclusions, 80,448 infants were available for analysis. Using linked health care utilization records, incident asthma cases developed after 36 months of age were identified. Extended Cox proportional hazards models were used to estimate hazard ratios while controlling for confounders. Exposure to corticosteroids during pregnancy was associated with a risk of asthma in childhood between 3–5 years of age: adjusted hazard ratio of 1.19 (95% confidence interval: 1.03, 1.39), with no association noted after 5 years of age: adjusted hazard ratio for 5–7 years was 1.06 (95% confidence interval: 0.86, 1.30) and for 8 or greater years was 0.74 (95% confidence interval: 0.54, 1.03). Antenatal steroid therapy appears to be an independent risk factor for the development of asthma between 3 and 5 years of age.