Socioeconomic and sociodemographic factors associated with asthma related outcomes in early childhood: the Generation R Study

Early-immune development in asthma: A review of the literature

This review presents a comprehensive examination of the various factors contributing to the immunopathogenesis of asthma from the prenatal to preschool period. We focus on the contributions of genetic and environmental components as well as the role of the nasal and gut microbiome on immune development. Predisposing genetic factors, including inherited genes associated with increased susceptibility to asthma, are discussed alongside environmental factors such as respiratory viruses and pollutant exposure, which can trigger or exacerbate asthma symptoms. Furthermore, the intricate interplay between the nasal and gut microbiome and the immune system is explored, emphasizing their influence on allergic immune development and response to environmental stimuli. This body of literature underscores the necessity of a comprehensive approach to comprehend and manage asthma, as it emphasizes the interactions of multiple factors in immune development and disease progression.

Developing Fractional Exhaled Nitric Oxide Predicted and Upper Limit of Normal Values for a Disadvantaged Population

BACKGROUND

Fractional exhaled nitric oxide (Feno), used as a biomarker, is influenced by several factors including ethnicity. Normative data are essential for interpretation, and currently single cutoff values are used in children and adults.

RESEARCH QUESTION

Accounting for factors that influence Feno, (1) what are appropriate predicted and upper limit of normal (ULN) Feno values in an underserved population (First Nations Australians), (2) how do these values compare with age-based interpretive guidelines, and (3) what factors influence Feno and what is the size of the effect?

STUDY DESIGN AND METHODS

Feno data of First Nations Australians (age < 16 years, n = 862; age ≥ 16 years, n = 348) were obtained. Medical history using participant questionnaires and medical records were used to define healthy participants. Flexible regression using spline functions, as used by the Global Lung Function Initiative, were used to generate predicted and ULN values.

RESULTS

Look-up tables for predicted and ULN values using age (4-76 years) and height (100-200 cm) were generated and are supplied with a calculator for clinician use. In healthy First Nations children (age < 18 years), ULN values ranged between 25 and 60 parts per billion (ppb) when considering only biologically plausible age and height combinations. For healthy adults, ULN values ranged between 39 and 88 ppb. Neither the current Feno interpretation guidelines, nor the currently recommended cutoff of 50 ppb for First Nations children 16 years of age or younger were appropriate for use in this cohort. Our modelling revealed that predicted and ULN values of healthy participants varied nonlinearly with age and height.

INTERPRETATION

Because single pediatric, adult, or all-age Feno cutoff values used by current interpretive guidelines to define abnormality fail to account for factors that modify Feno values, we propose predicted and ULN values for First Nations Australians 4 to 76 years of age. Creating age- and height-adjusted predicted and ULN values could be considered for other ethnicities.

Exploring the Link Between Neighborhood Violence and Health Among African-American and Latinx Youth Returning Home After Incarceration

Background

African-American and Latinx youth are disproportionately exposed to neighborhood violence and are overrepresented in the U.S. juvenile justice system. Perceived neighborhood violence is associated with negative health outcomes.

Objective

We examined associations between African-American and Latinx youths’ perceived neighborhood violence and health during reentry after juvenile incarceration.

Methods

Youth (n = 50) returning home after incarceration completed health questionnaires at one-month post-incarceration. A subset of participants (n = 25 youth) also participated in one-on-one, semi-structured longitudinal interviews.

Results

Twenty-eight (56%) participants reported neighborhood violence in quantitative surveys. Quantitative analyses revealed that perceived neighborhood violence was positively associated with reported asthma diagnosis, doctor recommendations for medical follow-up, perceived stress, and adverse childhood experiences (ACEs). Perceived neighborhood violence was negatively correlated with perceived family support. Stress ratings were associated with ACE total scores, moderate to severe depression symptoms, and family support. Moderate-to-severe depression symptoms were significantly correlated with lower ratings of family support. Qualitative interviews supplemented our quantitative findings and showed that responses to perceived neighborhood violence were linked to specific health-related behaviors, such as substance use or avoidance of gang activity.

Conclusions

Overall, our quantitative and qualitative results indicate that perceived neighborhood violence is associated with many negative psychosocial factors that could impact overall health and wellbeing of youth undergoing reentry. Treatment implications include the development and testing of family-centered interventions that help improve the transition back into the community for youth undergoing reentry and especially, their access to evidence-based treatment, including leveraging family telehealth substance use interventions.

Are wheezing, asthma and eczema in children associated with mother's health during pregnancy? Evidence from an Australian birth cohort

BACKGROUND

This study investigated the prevalence of wheezing, asthma, and eczema among Australian children using longitudinal data from birth to 15 years of age. This study also examined the association between maternal health status during pregnancy and their offspring's respiratory and allergic morbidities using sex-segregated data.

METHODS

This study used data from the Longitudinal Study of Australian Children (LSAC) where approximately 5000 children of a birth cohort across Australia were surveyed in 2004. These children were followed biennially in eight waves up to their age of 15 years until 2018. The status of the children's wheezing, asthma, and eczema were reported by the mothers upon doctors' diagnosis (for asthma) or self-assessment (for wheezing or eczema). Binomial logistic regression models were used to analyse associations between maternal health during pregnancy and their children's health outcomes.

RESULTS

Asthma prevalence among 0-1-year aged children was 11.7%, increased to 15.4% when the children were 10-11 years old, and then decreased to 13.6% when they were 14-15 years old. Wheezing and eczema were most prevalent when the children were 2-3 years old (26.0 and 17.8% respectively) and were least prevalent when the children were 14-15 years old (7.3 and 9.5% respectively). Maternal asthma, smoking during pregnancy, and pre-pregnancy obesity were significantly associated with an increased risk of wheezing and asthma in Australian children. Childhood eczema was associated only with maternal asthma. These associations were stronger among male children up to age 10-11 and during adolescence (12-15 years of age), female children were more prone to wheezing, asthma, and eczema.

CONCLUSION

This is a comprehensive longitudinal study of Australian children (0-15 years of age) to assess the prevalence (with sex-specific differences) of wheezing, asthma and eczema as well as the association between these respiratory and allergic morbidities and maternal health during pregnancy. The study findings suggest that careful medical and obstetric monitoring, improved specific age-sex wise risk factor prevention for children and health promotion for pregnant women would help protect child health.

Parental educational level and childhood wheezing and asthma: A prospective cohort study from the Japan Environment and Children's Study

BACKGROUND

The influence of mothers' and fathers' educational levels in separate evaluations of asthma has not been fully investigated. This study aims to examine the associations of the mother's and fathers' educational levels with childhood wheeze and asthma adjusting for crude and pre-and post-natal modifiable risk factors.

METHODS

We conducted a prospective cohort study using data from the Japan Environment and Children's Study, which recruited pregnant women from 2011 to 2014. The mother's and father's educational levels were surveyed by a questionnaire during the pregnancy, and childhood wheezing and doctor-diagnosed asthma were estimated using a 3-year questionnaire. Multilevel logistic regression analysis was performed to evaluate the association between the mother's and father's educational levels and childhood wheezing and asthma, adjusted for pre-and post-natal factors.

RESULTS

A total of 69,607 pairs of parents and their single infants were analyzed. We found 17.3% of children had wheezing and 7.7% had asthma. In crude analyses, lower educational level of parents was associated with an increased risk of childhood wheezing and asthma. After full adjustment, a lower educational level of mothers was associated with an increased risk of childhood asthma (junior high school (reference: high school); odds ratio (OR): 1.17, 95% CI, 1.01-1.36), and higher educational level, especially the mother's, was associated with an increased risk of childhood wheezing (technical junior college, technical/vocational college, or associate degree (ECD3); OR: 1.12, 95% CI, 1.06-1.18, bachelor's degree, or postgraduate degree; OR: 1.10, 95% CI, 1.03-1.18), and asthma (ECD3; OR: 1.13, 95% CI, 1.04-1.21).

CONCLUSIONS

Parents' lower educational level was a crude risk factor for childhood wheezing and asthma. However, an increased risk of wheezing due to mothers' higher educational level was found after adjusting for pre-and post-natal factors.

Sociodemographic factors, current asthma and lung function in an urban child population

BACKGROUND

We aimed to assess which sociodemographic factors are associated with current asthma and indicators of lung function in 10-year-old children.

METHODS

We analysed data of 5237 children (Mean age: 9.7, SD: 0.3) from the Generation R Study (2012-2016), a population-based cohort study in the Netherlands. Indicators of sociodemographic factors included parental educational level, net household income, financial difficulties, parental employment status and child ethnic background. Current asthma (yes/no) was defined as ever doctor-diagnosed-asthma combined with wheezing symptoms or asthma-medication use in the past 12 months. Lung function was measured by spirometry and included forced expiratory volume in 1 second (FEV₁ ), forced vital capacity (FVC), FEV₁ /FVC, and forced expiratory flow after exhaling 75% of FVC (FEF₇₅ ). Within-study sex-, height- and age-adjusted lung function measurements' z-scores were converted.

RESULTS

After adjustment for all sociodemographic factors, an independent association was observed between ethnic background with current asthma and lung function. Compared with children with a Dutch background, children with a nonwestern ethnic background had a higher odds of having current asthma (OR: 1.61, 95% CI: 1.02, 2.53), lower FVC z-score (-0.25, 95% CI: -0.35, -0.14), higher FEV₁ /FVC z-score (0.26, 95% CI: 0.14, 0.37) and higher FEF_75% z-score (0.15, 95% CI: 0.04, 0.25).

CONCLUSIONS

Among 10-year-old children, ethnic background was associated with current asthma and lung function after adjusting for a wide range of sociodemographic factors. No associations were found between socioeconomic status indicators and current asthma. Explanations for these associations such as language barriers, suboptimal care or pathophysiological differences require further investigation.

Fractional exhaled nitric oxide in preterm-born subjects: A systematic review and meta-analysis

BACKGROUND

Decreased lung function is common in preterm-born survivors. Increased fractional exhaled nitric oxide (FeNO) appears to be a reliable test for eosinophillic airway inflammation especially in asthma. We, systematically, reviewed the literature to compare FeNO levels in preterm-born children and adults who did or did not have chronic lung disease of prematurity (CLD) in infancy with term-born controls.

METHODS

We searched eight databases up to February 2018. Studies comparing FeNO levels in preterm-born subjects (<37 weeks' gestation) in childhood and adulthood with and without (CLD) with term-born subjects were identified and extracted by two reviewers. Data were analysed using Review Manager v5.3.

RESULTS

From 6042 article titles, 183 full articles were screened for inclusion. Nineteen studies met the inclusion criteria. Seventeen studies compared FeNO levels in preterm- and term-born children and adults; 11 studies (preterm n = 640 and term n = 4005) were included in a meta-analysis. The mean FeNO concentration difference between the preterm-born and term-born group was -0.74 (95% CI -1.88 to 0.41) ppb. For the six studies reporting data on CLD (preterm n = 204 and term n = 211) the mean difference for FeNO levels was -2.82 (95% CI -5.87 to 0.22) ppb between the preterm-born CLD and term-born groups.

CONCLUSIONS

Our data suggest that preterm born children with and without CLD have similar FeNO levels to term-born children suggesting an alternative mechanism to eosinophilic inflammation for symptoms of wheezing and airway obstruction observed in preterm-born subjects.

Is a low level of education a limiting factor for asthma control in a population with access to pulmonologists and to treatment?

OBJECTIVE

To determine whether a low level of education is a risk factor for uncontrolled asthma in a population of patients who have access to pulmonologists and to treatment.

METHODS

This was a cross-sectional study involving outpatients > 10 years of age diagnosed with asthma who were followed by a pulmonologist for at least 3 months in the city of Jundiai, located in the state of São Paulo, Brazil. The patients completed a questionnaire specifically designed for this study, the 6-item Asthma Control Questionnaire (to assess the control of asthma symptoms), and a questionnaire designed to assess treatment adherence. Patients underwent spirometry, and patient inhaler technique was assessed.

RESULTS

358 patients were enrolled in the study. Level of education was not considered a risk factor for uncontrolled asthma symptoms (OR = 0.99; 95% CI: 0.94-1.05), spirometry findings consistent with obstructive lung disease (OR = 1.00; 95% CI: 0.99-1.01), uncontrolled asthma (OR = 1.03; 95% CI: 0.95-1.10), or the need for moderate/high doses of inhaled medication (OR = 0.99; 95% CI: 0.94-1.06). The number of years of schooling was similar between the patients in whom treatment adherence was good and those in whom it was poor (p = 0.08), as well as between those who demonstrated proper inhaler technique and those who did not (p = 0.41).

CONCLUSIONS

Among asthma patients with access to pulmonologists and to treatment, a low level of education does not appear to be a limiting factor for adequate asthma control.

Maternal History of Childhood Abuse and Risk of Asthma and Allergy in 2-Year-Old Children

OBJECTIVES

Exposure to child abuse (CA) is associated with an increased risk of developing asthma and allergies; it is unknown if that risk is present across generations. This study investigated if 2-year-old children born to mothers with a history of CA were at an increased risk of receiving a diagnosis of asthma or allergies.

METHODS

Data from 1,551 participants were collected as part of the All Our Babies (AOB) study, a prospective pregnancy cohort. During pregnancy, each woman provided information about her own history of CA, and at 24 months postpartum, she provided information about her child's medical diagnoses. Symptoms of maternal depression and anxiety were assessed during pregnancy and at 24 months postpartum.

RESULTS

Unadjusted models showed that compared to children born to mothers without a history of CA, 2-year-old children born to mothers with a history of CA were more likely to have had a diagnosis of asthma (7.4% vs 4.2%, p = .016) or allergy (15.6% vs 9.2%, p < .001). Maternal symptoms of depression assessed in late pregnancy and symptoms of depression and anxiety at 24 months postpartum were significant mediators of the relationship between maternal CA and 2-year-old asthma diagnosis. Maternal symptoms of depression and anxiety assessed in late pregnancy were also significant mediators of the relationship between maternal CA and 2-year-old allergy diagnosis.

CONCLUSIONS

The results indicate that maternal exposure to CA is associated with increased risk of asthma and allergy in their 2-year-old children; symptoms of maternal depression and anxiety were identified as pathways linking the variables.

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.

Mode of delivery and childhood hospitalizations for asthma and other wheezing disorders

BACKGROUND

Observationally, delivery by Caesarean section is associated with higher risk of childhood asthma and wheeze in developed Western settings, but associations are less consistent in other settings.

OBJECTIVE

To examine the association of mode of delivery with hospitalizations for asthma and other wheezing disorders in a developed non-Western setting with high rates of Caesarean section.

METHODS

Using Cox regression, we examined the adjusted association of mode of delivery with public hospital admissions for asthma, bronchitis, and bronchiolitis (International Classification of Diseases, Ninth Version Clinical Modification 466, 490 and 493) from 9 days to 12 years of age in a population-representative prospective birth cohort of 8327 Chinese children in Hong Kong. Confounders included sex, birth and parental characteristics, and socio-economic position (SEP).

RESULTS

Delivery by Caesarean section accounted for 27% of all births and was not clearly associated with hospitalizations for asthma and other wheezing disorders to 12 years [hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.91 to 1.36] compared to vaginal delivery. Similarly, there were no clear associations to 2 years (HR 1.07, 95% CI 0.83 to 1.38) or 6 years (HR 1.12, 95% CI 0.91 to 1.37), although we cannot rule out residual confounding by SEP.

CONCLUSIONS AND CLINICAL RELEVANCE

We cannot rule out an association, but our findings suggest that the observed associations of delivery by Caesarean section with childhood wheezing disorders may vary with setting and may not be biologically mediated. Further studies with different designs are needed to clarify the role of the microbiome and mode of delivery in the aetiology of asthma and other childhood wheezing disorders.

Ethnic differences in asthma treatment among Swedish adolescents: A multilevel analysis of individual heterogeneity

AIMS

Adolescents with immigrant or ethnic minority background suffering from asthma receive on average less appropriate anti-asthmatic medication (AAM) than the majority population. However, those findings are based on analyses of differences between group averages which prevents our understanding of individual heterogeneity around the averages. Taking into account individual socioeconomic factors and medical needs, we performed multilevel analysis in order to evaluate if maternal country of birth (MCOB) accurately identifies adolescents with inappropriate AAM use.

METHODS

Using the Swedish Medical Birth Register, we identified all singleton children born between 1988 and 1991 who were residing in the country until they turned 17 and had complete information on the study variables. We applied a two-level multilevel logistic regression analysis with 62 MCOBs at the second and 755,894 children at the first level. Adjusting for socioeconomic and medical factors using a risk score, and including the socioeconomic characteristics of the MCOBs, we obtained both measures of association (odds ratio (OR)) and measures of variance (Intra-class correlation (ICC)).

RESULTS

Comparing with adolescents born from Swedish mothers, all other children had a lower AAM use, especially those whose mothers were from upper-middle- and low-income countries (OR = 0.47, 95% confidence interval: 0.35-0.61). However, the ICC was low (i.e., ICC ≈ 3%) for both preventive and relief AAM.

CONCLUSIONS

MCOB was associated to adolescent use of AAM. However, the small ICC indicates that MCOB is an inaccurate categorization for identifying inappropriate use of AAM among Swedish adolescents.

Asthma is Different in Women

Gender differences in asthma incidence, prevalence and severity have been reported worldwide. After puberty, asthma becomes more prevalent and severe in women, and is highest in women with early menarche or with multiple gestations, suggesting a role for sex hormones in asthma genesis. However, the impact of sex hormones on the pathophysiology of asthma is confounded by and difficult to differentiate from age, obesity, atopy, and other gender associated environmental exposures. There are also gender discrepancies in the perception of asthma symptoms. Understanding gender differences in asthma is important to provide effective education and personalized management plans for asthmatics across the lifecourse.

Relationship between prenatal antibiotic use and asthma in at-risk children

BACKGROUND

Asthma prevalence has doubled in developed countries during the past 30 years. Pre- and perinatal events are essential in shaping the development of the immune system and systemic antibiotic use during this time could alter the maternal or placental microbiome, leading to an increase in the child's risk of developing asthma.

OBJECTIVE

To determine whether prenatal antibiotic use is associated with asthma and wheezing in children at risk for asthma.

METHODS

Using data from a randomized education intervention of families at risk for asthma from 1998 followed through 2009 in urban Chicago, asthma was defined as ever having a physician asthma diagnosis by year 3 and wheezing in the third year. Logistic regression models controlling for confounders investigated the effect of antibiotic use during pregnancy on these outcomes.

RESULTS

After adjustment, prenatal antibiotic use was a risk factor for asthma (odds ratio 3.1, 95% confidence interval 1.4-6.8) but was only weakly associated with wheezing (odds ratio 1.8, 95% confidence interval 0.9-3.3). Analyses of the effects of timing of prenatal antibiotic use on asthma and wheezing showed the relation remained consistent for antibiotic use later in pregnancy, but the outcomes were not associated with antibiotic use in the first trimester.

CONCLUSION

This study suggests prenatal antibiotic use might be associated with the development of asthma in children at risk for asthma. Although the relation with prenatal antibiotics does not hold for wheezing in this study, there might be a trend that could be delineated further within a larger cohort study.