A systematic review of socioeconomic position in relation to asthma and allergic diseases

Wheeze trajectories are modifiable through early-life intervention and predict asthma in adolescence

BACKGROUND

The objectives of this study were to identify developmental trajectories of wheezing using data-driven methodology, and to examine whether trajectory membership differentially impacts the effectiveness of primary preventive efforts that target modifiable asthma risk factors.

METHODS

Secondary analysis of the Canadian Asthma Primary Prevention Study (CAPPS), a multifaceted prenatal intervention among children at high risk of asthma, followed from birth to 15 years. Wheezing trajectories were identified by latent class growth analysis. Predictors, intervention effects, and asthma diagnoses were examined between and within trajectory groups.

RESULTS

Among 525 children, 3 wheeze trajectory groups were identified: Low-Progressive (365, 69%), Early-Transient (52, 10%), and Early-Persistent (108, 21%). The study intervention was associated with lower odds of Early-Transient and Early-Persistent wheezing (P < .01). Other predictors of wheeze trajectories included, maternal asthma, maternal education, city of residence, breastfeeding, household pets, infant sex and atopy at 12 months. The odds of an asthma diagnosis were three-fold to six-fold higher in the Early-Persistent vs Low-Progressive group at all follow-up assessments (P = .03), whereas Early-Transient wheezing (limited to the first year) was not associated with asthma. In the Early-Persistent group, the odds of wheezing were lower among intervention than control children (adjusted odds ratio: 0.67; 95% CI: 0.48; 0.93) at 7 years.

CONCLUSIONS

Using data-driven methodology, children can be classified into clinically meaningful wheeze trajectory groups that appear to be programmed by modifiable and non-modifiable factors, and are useful for predicting asthma risk. Early-life interventions can alter some wheeze trajectories (ie, Early-Persistent) in infancy and reduce wheezing prevalence in mid-childhood.

Parental stress and air pollution increase childhood asthma in China

BACKGROUND

Although air pollution and social stress may independently increase childhood asthma, little is known on their synergistic effect on asthma, particularly in China with high levels of stress and air pollution.

OBJECTIVES

To examine associations between exposure to a combination of parental stress and air pollution and asthma prevalence in children.

METHODS

We conducted a cohort study of 2406 preschool children in Changsha (2011-2012). A questionnaire was used to collect children's lifetime prevalence of asthma and their parental stress. Parental socioeconomic and psychosocial stresses were respectively defined in terms of housing size and difficulty concentrating. Children's exposure to ambient air pollutants was estimated using concentrations measured at monitoring stations. Associations between exposure to parental stress and air pollution and childhood asthma were estimated by multiple logistic regression models using odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Life time prevalence of asthma in preschool children (6.7%) was significantly associated with parental socioeconomic and psychosocial stresses with OR (95% CI) respectively 1.48 (1.02-2.16) and 1.64 (1.00-2.71). Asthma was also associated with exposure to air pollutants, with adjusted OR (95% CI) during prenatal and postnatal periods respectively 1.43 (1.10-1.86) and 1.35 (1.02-1.79) for SO₂ and 1.61 (1.19-2.18) and 1.76 (1.19-2.61) for NO₂. The association with air pollution was significant only in children exposed to high parental stress, the association with parental stress was significant only in children exposed to high air pollution, and the association was the strongest in children exposed to a combination of parental stress and air pollution. Sensitivity analysis showed that the synergistic effects of parental stress and air pollution on childhood asthma were stronger in boys.

CONCLUSIONS

Parental stress and air pollution were synergistically associated with increased childhood asthma, indicating a common biological effect of parental stress and air pollution during both prenatal and postnatal periods.

Physical activity and asthma: cause or consequence? A bidirectional longitudinal analysis

BACKGROUND

There is increasing interest in the role physical activity (PA) can play in the development and management of asthma. Understanding whether PA can have a positive effect is hindered by the potential influence of asthma on PA and a lack of relevant longitudinal data, leading to a debate on the existence and direction of these links. The aim of this study was to explore whether having asthma results in lower PA levels, and/or whether lower PA levels lead to more asthma in children and adolescents.

METHODS

In a population-based study of 4983 children, data on asthma and PA were collected via questionnaires and time use diaries biennially, between the ages of 6 and 14. Current asthma was defined as use of asthma medications or wheeze in the past year, and incident asthma was defined as doctor's diagnosis since the previous wave. PA was time spent doing moderate-to-vigorous physical activities in a day. Bidirectionality of this relationship was investigated using cross-lagged structural equational models.

RESULTS

PA was not longitudinally associated with incident or current asthma. Similarly, there was no evidence that incident or current asthma predicted PA at any of the ages.

CONCLUSIONS

Using a novel strategy to investigate bidirectionality between PA and asthma, our results suggest that asthma and PA participation are not longitudinally associated in either direction. Our findings suggest that PA does not play an important role in the development or persistence of asthma.

Atopic Dermatitis: Disease Background and Risk Factors

Multiple risk factors have been associated with the development of atopic dermatitis (AD). Recent advances in understanding the role of genetics in this disease have been made, with discovery of the filaggrin (FLG) gene as the most notable so far. In addition to FLG gene mutations as a risk factor for AD, a positive family history of atopic or allergic disease in either parent, has been shown to confer a greater risk of developing AD. Atopic dermatitis usually presents early in life and is thought to represent the initial-step in the "atopic march" which is characterized by the development of other atopic diseases later in life such as asthma, allergic rhinitis and/or rhinoconjunctivitis, food allergies and hay fever. Other comorbid diseases that have been associated with AD include increase risk of viral and bacterial skin infections, neuropsychiatric diseases such as attention-deficit hyperactivity disorders (ADHD) and autistic spectrum disorder (ASD). Patients with AD, have also been found to have worse sleep quality overall compared to patients without AD. In this chapter, we will discuss the risk factors associated with development of atopic dermatitis as well as the most commonly reported comorbidities in patients with this disease.

The familial aggregation of atopic diseases and depression or anxiety in children

Background

Children with asthma and atopic diseases have an increased risk of depression or anxiety. Each of these diseases has strong genetic and environmental components; therefore, it seems likely that there is a shared liability rather than causative risk.

Objective

To investigate the existence and nature of familial aggregation for the comorbidity of atopic diseases and depression or anxiety.

Methods

Participants came from the Childhood and Adolescent Twin Study in Sweden (CATSS), n = 14 197. Current and ever asthma, eczema, hay fever and food allergy were reported by parents. Internalizing disorders were identified using validated questionnaires. Familial co‐aggregation analysis compared monozygotic (MZ) twins and same‐sex dizygotic (DZ) twins for atopic disease in 1 twin with internalizing disorder in the other to test for genetic liability. Several familial liability candidates were also tested including parental education, recent maternal psychological stress, childhood family trauma and parental country of birth.

Results

Familial co‐aggregation analysis found that if 1 twin had at least 1 current atopic disease the partner twin was at risk of having an internalizing disorder regardless of their own atopic status (adjusted OR 1.22 (95% CI 1.08, 1.37). Similar results were found for each atopic disease ever and current. MZ associations were not higher than DZ associations, suggesting that the liability is not genetic in nature. Including other familial candidates to the models made little difference to effect estimates.

Conclusions and Clinical Relevance

Atopic diseases and depression or anxiety tend to occur together in families; therefore, when treating for 1 disease, the physician should consider comorbidity in both the individual and the individual's siblings. We did not find evidence to support a genetic explanation for comorbidity, and further exploration is needed to disentangle the environmental and epigenetic reasons for familial aggregation.

Association between asthma and lung function in adolescents born very preterm: results of the EPIPAGE cohort study

Prematurity and bronchopulmonary dysplasia (BPD) affect long-term lung function. We studied the respiratory outcome of adolescents born very preterm and controls from the Etude EPIdémiologique sur les Petits Ages Gestationnels cohort and analysed their current lung function in relation to asthma symptoms (categorised in three age groups) from birth. In models including BPD, asthma at each age and confounding factors in the preterm group, BPD and preschool wheeze were the only independent variables associated with FEV₁ Preschool wheeze is an independent factor associated with FEV₁ impairment in adolescents born very preterm. These results highlight the need for optimal management of early respiratory symptoms in preterm-born infants. TRIAL REGISTRATION NUMBER: Results, NCT01424553.

The MEGA Project: A Study of the Mechanisms Involved in the Genesis and Disease Course of Asthma. Asthma Cohort Creation and Long-Term Follow-Up

The general aim of this study is to create a cohort of asthma patients with varying grades of severity in order to gain greater insight into the mechanisms underlying the genesis and course of this disease. The specific objectives focus on various studies, including imaging, lung function, inflammation, and bronchial hyperresponsiveness, to determine the relevant events that characterize the asthma population, the long-term parameters that can determine changes in the severity of patients, and the treatments that influence disease progression. The study will also seek to identify the causes of exacerbations and how this affects the course of the disease. Patients will be contacted via the outpatient clinics of the 8 participating institutions under the auspices of the Spanish Respiratory Diseases Networking System (CIBER). In the inclusion visit, a standardized clinical history will be obtained, a clinical examination, including blood pressure, body mass index, complete respiratory function tests, and FENO will be performed, and the Asthma Control Test (ACT), Morisky-Green test, Asthma Quality of Life Questionnaire (Mini AQLQ), the Sino-Nasal Outcome Test 22 (SNOT-22), and the Hospital Anxiety and Depression scale (HADS) will be administered. A specific electronic database has been designed for data collection. Exhaled breath condensate, urine and blood samples will also be collected. Non-specific bronchial hyperresponsiveness testing with methacholine will be performed and an induced sputum sample will be collected at the beginning of the study and every 24 months. A skin prick test for airborne allergens and a chest CT will be performed at the beginning of the study and repeated every 5 years.

Health care access, concentrated poverty, and pediatric asthma hospital care use in California's San Joaquin Valley: A multilevel approach

BACKGROUND

California's San Joaquin Valley is a region with a history of poverty, low health care access, and high rates of pediatric asthma. It is important to understand the potential barriers to care that challenge vulnerable populations.

OBJECTIVE

The objective was to describe pediatric asthma-related utilization patterns in the emergency department (ED) and hospital by insurance coverage as well as to identify contributing individual-level indicators (age, sex, race/ethnicity, and insurance coverage) and neighborhood-level indicators of health care access.

METHODS

This was a retrospective study based on secondary data from California hospital and ED records 2007-2012. Children who used services for asthma-related conditions, were aged 0-14 years, Hispanic or non-Hispanic white, and resided in the San Joaquin Valley were included in the analysis. Poisson multilevel modeling was used to control for individual- and neighborhood-level factors.

RESULTS

The effect of insurance coverage on asthma ED visits and hospitalizations was modified by the neighborhood-level percentage of concentrated poverty (RR = 1.01, 95% CI = 1.01-1.02; RR = 1.03, 95% CI = 1.02-1.04, respectively). The effect of insurance coverage on asthma hospitalizations was completely explained by the neighborhood-level percentage of concentrated poverty.

CONCLUSIONS

Observed effects of insurance coverage on hospital care use were significantly modified by neighborhood-level measures of health care access and concentrated poverty. This suggests not only an overall greater risk for poor children on Medi-Cal, but also a greater vulnerability or response to neighborhood social factors such as socioeconomic status, community cohesiveness, crime, and racial/ethnic segregation.

Land cover and air pollution are associated with asthma hospitalisations: A cross-sectional study

BACKGROUND

There is increasing policy interest in the potential for vegetation in urban areas to mitigate harmful effects of air pollution on respiratory health. We aimed to quantify relationships between tree and green space density and asthma-related hospitalisations, and explore how these varied with exposure to background air pollution concentrations.

METHODS

Population standardised asthma hospitalisation rates (1997-2012) for 26,455 urban residential areas of England were merged with area-level data on vegetation and background air pollutant concentrations. We fitted negative binomial regression models using maximum likelihood estimation to obtain estimates of asthma-vegetation relationships at different levels of pollutant exposure.

RESULTS

Green space and gardens were associated with reductions in asthma hospitalisation when pollutant exposures were lower but had no significant association when pollutant exposures were higher. In contrast, tree density was associated with reduced asthma hospitalisation when pollutant exposures were higher but had no significant association when pollutant exposures were lower.

CONCLUSIONS

We found differential effects of natural environments at high and low background pollutant concentrations. These findings can provide evidence for urban planning decisions which aim to leverage health co-benefits from environmental improvements.

Association between childhood allergic diseases, educational attainment and occupational status in later life: systematic review protocol

INTRODUCTION

Childhood allergic diseases may prevent affected children from achieving their academic potential. Potential mechanisms include absence from school due to illness and medical appointments. Experience of symptoms in classes or leisure time, and stigma associated with visible signs and symptoms, including skin disease, requirements for medication during school time or the need for specific diets, may also contribute to reduced educational attainment. Studies have investigated the association between specific allergic diseases and educational attainment. The aim of this study is to systematically review the literature on allergic diseases, educational attainment and occupational status, and if possible, calculate meta-analytic summary estimates for the associations.

METHODS

Systematic electronic searches in Medline, EMBASE, Cochrane, Cumulative Index to Nursing & Allied Health Literature (CINAHL), PsycINFO and education Resources Information Center (ERIC); hand search in reference lists of included papers and conference reports; search for unpublished studies in clinical trial registers and the New York Academy of Medicine Grey Literature Report; data extraction; and study quality assessment (Newcastle-Ottawa Scale) will be performed.

ANALYSIS

Data will be summarised descriptively, and meta-analysis including meta-regression to explore sources of heterogeneities will be performed if possible.

ETHICS AND DISSEMINATION

Dissemination in a peer-reviewed, open-access, international scientific journal is planned.

PROSPERO REGISTRATION NUMBER

CRD42017058036.

Identification and validation of asthma phenotypes in Chinese population using cluster analysis

BACKGROUND

Asthma is a heterogeneous airway disease, so it is crucial to clearly identify clinical phenotypes to achieve better asthma management.

OBJECTIVE

To identify and prospectively validate asthma clusters in a Chinese population.

METHODS

Two hundred eighty-four patients were consecutively recruited and 18 sociodemographic and clinical variables were collected. Hierarchical cluster analysis was performed by the Ward method followed by k-means cluster analysis. Then, a prospective 12-month cohort study was used to validate the identified clusters.

RESULTS

Five clusters were successfully identified. Clusters 1 (n = 71) and 3 (n = 81) were mild asthma phenotypes with slight airway obstruction and low exacerbation risk, but with a sex differential. Cluster 2 (n = 65) described an "allergic" phenotype, cluster 4 (n = 33) featured a "fixed airflow limitation" phenotype with smoking, and cluster 5 (n = 34) was a "low socioeconomic status" phenotype. Patients in clusters 2, 4, and 5 had distinctly lower socioeconomic status and more psychological symptoms. Cluster 2 had a significantly increased risk of exacerbations (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.03-1.25), unplanned visits for asthma (RR 1.98, 95% CI 1.07-3.66), and emergency visits for asthma (RR 7.17, 95% CI 1.26-40.80). Cluster 4 had an increased risk of unplanned visits (RR 2.22, 95% CI 1.02-4.81), and cluster 5 had increased emergency visits (RR 12.72, 95% CI 1.95-69.78). Kaplan-Meier analysis confirmed that cluster grouping was predictive of time to the first asthma exacerbation, unplanned visit, emergency visit, and hospital admission (P < .0001 for all comparisons).

CONCLUSION

We identified 3 clinical clusters as "allergic asthma," "fixed airflow limitation," and "low socioeconomic status" phenotypes that are at high risk of severe asthma exacerbations and that have management implications for clinical practice in developing countries.

Correlation between socio-economic status and atopic dermatitis in Korean adults: the Korea national health and nutrition examination survey (2007-2014)

INTRODUCTION

Atopic dermatitis (AD) is one of the most common allergic diseases. Its prevalence has been increasing in recent decades. Socio-economic status is well-known risk factor of allergic diseases.

OBJECTIVE

This study was performed to investigate the relationship between socio-economic status and AD in Korean adults.

METHODS

Data were acquired from 47 351 men and women, ≥19 years of age who participated in the Korea National Health and Nutrition Examination Surveys (KNHANES) conducted from 2007 to 2014. The presence of AD was based on self-reported physician diagnosis of AD in the Health Interview Surveys.

RESULTS

The prevalence of AD was 3.1%, which decreased with increasing age. In univariate analysis, adults with AD were prone to be female, younger, never-married, well educated, lower household members, and urban dwelling (all P < 0.01). Monthly family income and smoking status were not associated with the presence of AD. The prevalence of hypertension, diabetes mellitus and asthma was higher in AD subjects (all P < 0.01), while obesity was not associated with adult AD. After adjusting for confounders, logistic regression analysis showed female sex (adjusted odds ratio [aOR]: 1.483, 95% CI: 1.268-1.734), age (P < 0.01), marital status (Single: aOR: 1.307, 95% CI: 1.012-1.690; Never-married: aOR: 1.938, 95% CI: 1.513-2.482), urban residence (aOR: 1.281, 95% CI: 1.045-1.569) and asthma (aOR: 1.788, 95% CI: 1.416-2.258) were associated with higher prevalence of AD (all P < 0.01).

CONCLUSION

Female sex, age, marital status, urban residence, and the presence of asthma are important risk factors of the prevalence of AD in Korean adults.

A pilot randomised controlled trial investigating a Mediterranean diet intervention in pregnant women for the primary prevention of allergic diseases in infants

BACKGROUND

Observational studies suggest a potentially protective role of the Mediterranean diet (MD) in allergic diseases, including asthma. Large scale randomised controlled trials (RCTs) are needed to test the hypothesised allergy-prevention benefits of a MD during pregnancy. The present two-arm pilot RCT in pregnant women at high-risk of having a child who would develop allergic disease investigated maternal recruitment, retention and acceptability of an MD dietary intervention in the UK. The trial also assessed the effect of the intervention on MD adherence scores at 12 and at 24 weeks post-randomisation.

METHODS

Thirty women were recruited at around 12 weeks of gestation. Retention was high (28 out of 30; 93%). The intervention was acceptable to participants. Mean (SD) adherence to the MD at baseline was 12.4 (2.9) in the intervention arm (n = 14) and 13.0 (1.9) in the control arm (n = 16), where 24 represents maximal adherence. There was a favourable short-term change in MD score: the adjusted mean difference (intervention - control) in the change in MD score from baseline to 12 weeks post-randomisation was 2.4 (95% confidence interval = 0.6-4.2, P = 0.012).

CONCLUSIONS

The trial provides important insights into recruitment, retention and sustaining the dietary intervention, which will be used in the design of a large RCT.

Susceptibility Factors Relevant for the Association Between Long-Term Air Pollution Exposure and Incident Asthma

In this review, we identified 15 studies in children and 10 studies in adults that assessed the association between long-term exposure to air pollution and incident asthma and that conducted stratified analyses to explore potential susceptibility factors. Overall, adult never-/former smokers seem to be at higher risk of incident asthma due to air pollution. Children without atopy and children from low socioeconomic status families also seem to be at higher risk of incident asthma due to air pollution. While interaction between air pollution and genes involved in the response to oxidative stress pathways have been explored, results are somewhat inconsistent and in need of replication. To evaluate interactions, large sample sizes are necessary, and much more research, including data pooling from existing studies, is needed to further explore susceptibility factors for asthma incidence due to long-term air pollution exposure.

Co-occurrence and clustering of health conditions at age 11: cross-sectional findings from the Millennium Cohort Study

OBJECTIVES

To identify patterns of co-occurrence and clustering of 6 common adverse health conditions in 11-year-old children and explore differences by sociodemographic factors.

DESIGN

Nationally representative prospective cohort study.

SETTING

Children born in the UK between 2000 and 2002.

PARTICIPANTS

11 399 11-year-old singleton children for whom data on all 6 health conditions and sociodemographic information were available (complete cases).

MAIN OUTCOME MEASURES

Prevalence, co-occurrence and clustering of 6 common health conditions: wheeze; eczema; long-standing illness (excluding wheeze and eczema); injury; socioemotional difficulties (measured using Strengths and Difficulties Questionnaire) and unfavourable weight (thin/overweight/obese vs normal).

RESULTS

42.4% of children had 2 or more adverse health conditions (co-occurrence). Co-occurrence was more common in boys and children from lower income households. Latent class analysis identified 6 classes: 'normative' (57.4%): 'atopic burdened' (14.0%); 'socioemotional burdened' (11.0%); 'unfavourable weight/injury' (7.7%); 'eczema/injury' (6.0%) and 'eczema/unfavourable weight' (3.9%). As with co-occurrence, class membership differed by sociodemographic factors: boys, children of mothers with lower educational attainment and children from lower income households were more likely to be in the 'socioemotional burdened' class. Children of mothers with higher educational attainment were more likely to be in the 'normative' and 'eczema/unfavourable weight' classes.

CONCLUSIONS

Co-occurrence of adverse health conditions at age 11 is common and is associated with adverse socioeconomic circumstances. Holistic, child focused care, particularly in boys and those in lower income groups, may help to prevent and reduce co-occurrence in later childhood and adolescence.

Association of neighborhood crime with asthma and asthma morbidity among Mexican American children in Chicago, Illinois

BACKGROUND

There is increasing evidence that neighborhood-level factors, in addition to individual-level factors, may contribute directly or indirectly to childhood asthma by affecting environmental and lifestyle factors. Exposure to neighborhood crime and violence has been associated with poor health outcomes, especially among underserved and minority populations, and its effect on respiratory health is an area of active research.

OBJECTIVE

To examine the association of residential neighborhood crime with asthma and asthma-related outcomes among Mexican American children.

METHODS

This cross-sectional study was conducted with parents of 2,023 Mexican American children. We derived measures of neighborhood (census tract) violent, property, and drug abuse crime and used multilevel generalized estimating equations to test associations of neighborhood crime counts with respiratory conditions.

RESULTS

In multiple regression models, a 1-SD increase in neighborhood property crimes significantly increased the odds of lifetime asthma, lifetime wheezing, lifetime emergency department (ED) visits attributable to asthma or wheezing, and lifetime hospitalization attributable to asthma or wheezing by 25%, 18%, 44%, and 62%, respectively. A 1-SD elevation in neighborhood violent crime was positively and significantly associated with 21% and 57% higher odds of lifetime wheezing and ED visits, respectively. We also observed 13% and 44% significantly increased odds of lifetime wheezing and ED visits, respectively, for a 1-SD increase in drug abuse crime. These findings were not explained or modified by individual- and neighborhood-level covariates.

CONCLUSION

Higher neighborhood crime was associated with greater odds of asthma and asthma morbidity in Mexican American children.

The role of socioeconomic position as an effect-modifier of the association between outdoor air pollution and children's asthma exacerbations: an equity-focused systematic review

BACKGROUND

The role of socioeconomic position (SEP) as an effect modifier of the association between asthma exacerbations and outdoor air pollution remains unclear.

OBJECTIVE

To identify and summarize the evidence regarding SEP as an effect modifier of the association between asthma exacerbations and outdoor air pollution in children.

METHODS

We conducted searches in five electronic databases from January 1950 to June 2015 with no language restriction. Observational studies involving children, measuring any non-biological outdoor air pollutant exposure, resulting in any asthma-related health service use, and reporting measures of effect by individual or aggregated SEP measures were included.

RESULTS

Ten studies met the inclusion criteria. Five studies reported on hospitalizations, three on emergency department visits, one on ambulatory visits, and one on repeat hospital visits. Six studies identified differential effects of the effect of air pollution on asthma outcomes by SEP with stronger effects for children with a low SEP level; however, the analysis of interaction between air pollutants and SEP was significant in one study of asthma hospitalizations only. The differential effect was reported using individual and aggregated SEP measures.

CONCLUSION

This review reveals that there is weak evidence of SEP as an effect-modifier of the association between air pollution and children's asthma exacerbations. While stronger negative effects on asthma-related hospitalizations occur for children living in a lower SEP, the sample size of some of the original studies limited the statistical assessment of the modification effect.

Biodiversity, the Human Microbiome and Mental Health: Moving toward a New Clinical Ecology for the 21st Century?

Advances in research concerning the brain-related influences of the microbiome have been paradigm shifting, although at an early stage, clinical research involving beneficial microbes lends credence to the notion that the microbiome may be an important target in supporting mental health (defined here along the continuum between quality of life and the criteria for specific disorders). Through metagenomics, proteomics, metabolomics, and systems biology, a new emphasis to personalized medicine is on the horizon. Humans can now be viewed as multispecies organisms operating within an ecological theatre; it is important that clinicians increasingly see their patients in this context. Historically marginalized ecological aspects of health are destined to become an important consideration in the new frontiers of practicing medicine with the microbiome in mind. Emerging evidence indicates that macrobiodiversity in the external environment can influence mental well-being. Local biodiversity may also drive differences in human-associated microbiota; microbial diversity as a product of external biodiversity may have far-reaching effects on immune function and mood. With a focus on the microbiome as it pertains to mental health, we define environmental “grey space” and emphasize a new frontier involving bio-eco-psychological medicine. Within this concept the ecological terrain can link dysbiotic lifestyles and biodiversity on the grand scale to the local human-associated microbial ecosystems that might otherwise seem far removed from one another.

Individual factors, neighborhood social context and asthma at age 5 years

OBJECTIVE

Childhood asthma is a major public health problem and its development is multifactorial. We examined whether neighborhood cohesion and disorder were associated with caregiver-report of asthma at age 5 years.

METHODS

This study is a secondary data analysis of the 2011-2012 United States National Survey of Children's Health. Data were available for 4680 children, age 5 years old born at term or preterm with birthweight >2500 g. Neighborhood disorder and cohesion were assessed based on caregivers' responses to validated questionnaires. Child asthma diagnosis was reported by the caregiver. Multivariable logistic regression was used to examine the relationship between these neighborhood factors and caregiver-report of child asthma, while accounting for individual level covariates.

RESULTS

Approximately two-thirds of the 4680 children were White and lived in households with income >400% of federal poverty line. Asthma was present in 399 (9%) children. Child female sex was associated with reduced risk of caregiver-reported asthma while non-Hispanic Black race and having smokers in the household were independently associated with increased risk in multivariable models. In these models, neighborhood disorder was significantly associated with asthma (adjusted Odds Ratio [aOR] 1.70, 95% Confidence Interval [CI] 1.04-2.78), while neighborhood cohesion was not (aOR 0.93, 95% CI 0.51-1.68).

CONCLUSION

Even after adjustment for several individual level factors, neighborhood disorder was associated with caregiver-report of asthma in this nationally representative sample of 5-year-old children. Further research is needed to better understand how risk factors at different levels of the socio-ecological framework may interact to affect childhood asthma development.

GP utilisation by education level among adults with COPD or asthma: a cross-sectional register-based study

There is a marked socioeconomic gradient in the prevalence of chronic obstructive pulmonary disease (COPD) and asthma, but a large proportion of patients remain undiagnosed. It is a challenge for general practitioners (GPs) to both identify patients and contribute to equity and high quality in services delivered. The aim of this study was to identify patients with COPD and asthma diagnoses recorded by GPs and explore their utilisation of GP services by education level. This was a cross-sectional, national, register-based study from Norwegian general practice in the period 2009–2011. Based on claims from GPs, the number of patients aged ⩾40 years with a diagnosis of COPD or asthma and their GP services utilisation were estimated and linked to the national education database. Multivariate Poisson and logistic regression models were used to explore the variations in GP utilisation. In the population aged ⩾40 years, 2.8% had COPD and 3.8% had asthma according to GPs’ diagnoses. COPD was four times more prevalent in patients with basic education than higher education; this increase was ⩽80% for asthma. Consultation rates were 12% higher (P<0.001) for COPD and 25% higher (P<0.001) for asthma in patients with low versus high education in the age group of 40–59 years after adjusting for comorbidity, and patient and GP characteristics. Approximately 25% of COPD patients and 20% of asthma patients had ⩾1 spirometry test in general practice in 2011, with no significant education differences in adjusted models. The higher consultation rate in lower-education groups indicates that GPs contribute to fair distribution of healthcare.

Social inequalities in wheezing in children: findings from the UK Millennium Cohort Study

Wheezing in childhood is socially patterned, but it is unclear what factors explain the social differences.Regression analysis of the UK Millennium Cohort Study, based on 11 141 singleton children who participated at ages 9 months and 3, 5 and 7 years. Relative risk ratios (RRR) for early and persistent/relapsing wheeze were estimated using multinomial regression, according to measures of socioeconomic circumstances. Maternal, antenatal and early-life characteristics were assessed as potential mediators.Children of mothers with no educational qualifications were more likely to have both wheeze types, compared to children of mothers with degree-level qualifications (RRR 1.53, 95% CI 1.26-1.86 for early wheeze; 1.32 95% CI 1.04-1.67 for persistent/relapsing wheeze). Controlling for maternal age, smoking during pregnancy and breastfeeding removed the elevated risk of wheezing. Male sex, maternal age, body mass index, atopy, smoking during pregnancy, preterm birth, breastfeeding, exposure to other children and furry pets were independently associated with wheezing, but the pattern of association varied between wheezing types.In this representative UK cohort, adjustment for maternal smoking during pregnancy and breastfeeding removed the socioeconomic inequalities in common wheezing phenotypes. Policies to reduce the social gradient in these risk factors may reduce inequalities in wheezing and asthma.

Do early-life exposures explain why more advantaged children get eczema? Findings from the U.K. Millennium Cohort Study

Background

Atopic dermatitis (eczema) in childhood is socially patterned, with higher incidence in more advantaged populations. However, it is unclear what factors explain the social differences.

Objectives

To identify early‐life risk factors for eczema, and to explore how early‐life risk factors explain any differences in eczema.

Methods

We estimated odds ratios (ORs) for ever having had eczema by age 5 years in 14 499 children from the U.K. Millennium Cohort Study (MCS), with a focus on maternal, antenatal and early‐life risk factors and socioeconomic circumstances (SECs). Risk factors were explored to assess whether they attenuated associations between SECs and eczema.

Results

Overall 35·1% of children had ever had eczema by age 5 years. Children of mothers with degree‐level qualifications vs. no educational qualifications were more likely to have eczema (OR 1·52, 95% confidence interval 1·31–1·76), and there was a gradient across the socioeconomic spectrum. Maternal atopy, breastfeeding (1–6 weeks and ≥ 6 months), introduction of solids under 4 months or cow's milk under 9 months, antibiotic exposure in the first year of life and grime exposure were associated with an increased odds of having eczema. Female sex, Pakistani and Bangladeshi ethnicity, smoking during pregnancy, exposure to environmental tobacco smoke and having more siblings were associated with reduced odds for eczema. Controlling for maternal, antenatal and early‐life characteristics (particularly maternal smoking during pregnancy, breastfeeding and number of siblings) reduced the OR for eczema to 1·26 (95% confidence interval 1·03–1·50) in the group with the highest educational qualifications compared with the least.

Conclusions

In a representative U.K. child cohort, eczema was more common in more advantaged children. This was explained partially by early‐life factors including not smoking during pregnancy, breastfeeding and having fewer siblings.

What's already known about this topic?

Previous studies have suggested that atopic dermatitis (eczema) in childhood is socially patterned, with higher incidence in more advantaged populations.

It is unclear what explains these differences.

What does this study add?

This large longitudinal study confirmed a significant excess of atopic dermatitis in more advantaged children born in 2000.

This could be explained partially by maternal and early‐life factors including less maternal smoking in pregnancy, prolonged breastfeeding and fewer siblings.

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Clostridium butyricum in combination with specific immunotherapy converts antigen-specific B cells to regulatory B cells in asthmatic patients

The effect of antigen specific immunotherapy (SIT) on asthma is supposed to be improved. Published data indicate that administration of probiotics alleviates allergic diseases. B cells play important roles in the pathogenesis of allergic diseases. This study aims to modulate antigen specific B cell property by the administration of Clostridium butyrate (CB) in combination with SIT. The results showed that after a 3-month treatment, the total asthma clinical score and serum specific IgE were improved in the patients treated with SIT, which was further improved in those treated with both SIT and CB, but not in those treated with CB alone. Treatment with SIT and CB increased p300 and STAT3 activation, up regulated the IL-10 gene transcription and increased the frequency of peripheral antigen specific B cells. In conclusion, administration with SIT in combination with CB converts Der p 1 specific B cells to regulatory B cells in asthma patients allergic to Der p 1. The data suggest a potential therapeutic remedy in the treatment of allergic diseases.

Socioeconomic and sociodemographic factors related to allergic diseases in Korean adolescents based on the Seventh Korea Youth Risk Behavior Web-based Survey: a cross-sectional study

Background

Various international reports have shown that socioeconomic and sociodemographic variables are correlated with allergic diseases; however, little is known about how these variables affect Korean adolescents. This study was conducted to identify socioeconomic and sociodemographic risk factors for allergic diseases in Korean adolescents to provide information for preventing and managing such conditions.

Methods

Data from the 2011 Korea Youth Risk Behavior Web-based Survey (KYRBWS-VII) of 75,643 adolescents were used. An anonymously administered online survey was conducted to collect dependent variable information on perceived sexes, residence, family affluence (Family Affluence Scale; FAS), parental education levels, subjective academic achievement, obesity, drinking and smoking. The independent variables were asthma, allergic rhinitis and atopic dermatitis. Multivariate logistic regression was used to analyze the correlations between the dependent and independent variables.

Results

Low subjective academic achievement, obesity, drinking and smoking were risk factors for asthma. High FAS, parental bachelor’s degree and high subjective academic achievement were risk factors for allergic rhinitis. Finally, high FAS, maternal bachelor’s degree and high subjective academic achievement were risk factors for atopic dermatitis.

Conclusion

We found that high socioeconomic status (SES) was a risk factor for allergic diseases in Korean adolescents. We propose that the greater access to medical services and immunization (e.g., hygiene hypothesis) afforded by high SES influenced the prevalence of allergic diseases. Thus, as the Korean economy develops further, the prevalence of allergic diseases is likely to increase. Controlling harmful behavioral risk factors, such as drinking and smoking, may help to prevent adolescent allergic diseases.

Childhood wheezing, asthma, allergy, atopy, and lung function: different socioeconomic patterns for different phenotypes

Identifying preventable exposures that lead to asthma and associated allergies has proved challenging, partly because of the difficulty in differentiating phenotypes that define homogeneous disease groups. Understanding the socioeconomic patterns of disease phenotypes can help distinguish which exposures are preventable. In the present study, we identified disease phenotypes that are susceptible to socioeconomic variation, and we determined which life-course exposures were associated with these inequalities in a contemporary birth cohort. Participants included children from the Avon Longitudinal Study of Parents and Children, a population-based birth cohort in England, who were born in 1991 and 1992 and attended the clinic at 7–8 years of age (n = 6,378). Disease phenotypes included asthma, atopy, wheezing, altered lung function, and bronchial reactivity phenotypes. Combining atopy with a diagnosis of asthma from a doctor captured the greatest socioeconomic variation, including opposing patterns between phenotype groups: Children with a low socioeconomic position (SEP) had more asthma alone (adjusted multinomial odds ratio = 1.50, 95% confidence interval: 1.21, 1.87) but less atopy alone (adjusted multinomial odds ratio = 0.80, 95% confidence interval: 0.66, 0.98) than did children with high SEP. Adjustment for maternal exposure to tobacco smoke during pregnancy and childhood exposure to tobacco smoke reduced the odds of asthma alone in children with a low SEP. Current inequalities among children who have asthma but not atopy can be prevented by eliminating exposure to tobacco smoke. Other disease phenotypes were not socially patterned or had SEP patterns that were not related to smoke exposure.

Impact of socioeconomic and environmental factors on atopic eczema and allergic rhinitis: a cross sectional study

The prevalence of allergic rhinitis and atopic eczema is on the rise in recent decades. Many factors can be related to the development of these diseases. We aimed to investigate the association between socioeconomic status (SES), environmental risk factors and these conditions. In this study, the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was translated and validated. Then it was used to determine the prevalence, severity and possible related factors for both diseases in 1904 schoolchildren aged 6-7 and 13-14 years from various regions of Tehran. The prevalence of rhinitis and eczema in the past year was 33.2 % and 8.2 %, respectively. The prevalence of rhinoconjunctivitis in the past year was 30 %. The risk factors such as birth order, nursery attendance, pet ownership, past allergic experiences as well as some SES factors were associated with both conditions. The prevalence of allergic rhinitis and atopic eczema was on the rise in comparison to the previous studies and SES as well as environmental factors are thought to be associated with the prevalence of these conditions.

Disabling chronic conditions in childhood and socioeconomic disadvantage: a systematic review and meta-analyses of observational studies

OBJECTIVE

To determine the association of socioeconomic disadvantage with the prevalence of childhood disabling chronic conditions in high-income countries.

STUDY DESIGN

Systematic review and meta-analyses.

DATA SOURCES

6 electronic databases, relevant websites, reference lists and experts in the field.

STUDY SELECTION

160 observational studies conducted in high-income countries with data on socioeconomic status and disabling chronic conditions in childhood, published between 1 January 1991 and 31 December 2013.

DATA EXTRACTION AND SYNTHESIS

Abstracts were reviewed, full papers obtained, and papers identified for inclusion by 2 independent reviewers. Inclusion decisions were checked by a third reviewer. Where reported, ORs were extracted for low versus high socioeconomic status. For studies reporting raw data but not ORs, ORs were calculated. Narrative analysis was undertaken for studies without data suitable for meta-analysis.

RESULTS

126 studies had data suitable for meta-analysis. ORs for risk estimates were: all-cause disabling chronic conditions 1.72 (95% CI 1.48 to 2.01); psychological disorders 1.88 (95% CI 1.68 to 2.10); intellectual disability 2.41 (95% CI 2.03 to 2.86); activity-limiting asthma 2.20 (95% CI 1.87 to 2.85); cerebral palsy 1.42 (95% CI 1.26 to 1.61); congenital abnormalities 1.41 (95% CI 1.24 to 1.61); epilepsy 1.38 (95% CI 1.20 to 1.59); sensory impairment 1.70 (95% CI 1.39 to 2.07). Heterogeneity was high across most estimates (I(2)>75%). Of the 34 studies without data suitable for meta-analysis, 26 reported results consistent with increased risk associated with low socioeconomic status.

CONCLUSIONS

The findings indicate that, in high-income countries, childhood disabling chronic conditions are associated with social disadvantage. Although evidence of an association is consistent across different countries, the review provides limited evidence to explain the association; future research, using longitudinal data, will be required to distinguish low socioeconomic status as the cause or consequence of childhood disabling chronic conditions and the aetiological pathways and mechanisms.