Inflammatory and Comorbid Features of Patients with Severe Asthma and Frequent Exacerbations

RATIONALE

Reducing asthma exacerbation frequency is an important criterion for approval of asthma therapies, but the clinical features of exacerbation-prone asthma (EPA) remain incompletely defined.

OBJECTIVES

To describe the clinical, physiologic, inflammatory, and comorbidity factors associated with EPA.

METHODS

Baseline data from the NHLBI Severe Asthma Research Program (SARP)-3 were analyzed. An exacerbation was defined as a burst of systemic corticosteroids lasting 3 days or more. Patients were classified by their number of exacerbations in the past year: none, few (one to two), or exacerbation prone (≥3). Replication of a multivariable model was performed with data from the SARP-1 + 2 cohort.

MEASUREMENTS AND MAIN RESULTS

Of 709 subjects in the SARP-3 cohort, 294 (41%) had no exacerbations and 173 (24%) were exacerbation prone in the prior year. Several factors normally associated with severity (asthma duration, age, sex, race, and socioeconomic status) did not associate with exacerbation frequency in SARP-3; bronchodilator responsiveness also discriminated exacerbation proneness from asthma severity. In the SARP-3 multivariable model, blood eosinophils, body mass index, and bronchodilator responsiveness were positively associated with exacerbation frequency (rate ratios [95% confidence interval], 1.6 [1.2-2.1] for every log unit of eosinophils, 1.3 [1.1-1.4] for every 10 body mass index units, and 1.2 [1.1-1.4] for every 10% increase in bronchodilatory responsiveness). Chronic sinusitis and gastroesophageal reflux were also associated with exacerbation frequency (1.7 [1.4-2.1] and 1.6 [1.3-2.0]), even after adjustment for multiple factors. These effects were replicated in the SARP-1 + 2 multivariable model.

CONCLUSIONS

EPA may be a distinct susceptibility phenotype with implications for the targeting of exacerbation prevention strategies. Clinical trial registered with www.clinicaltrials.gov (NCT 01760915).

Stress and Bronchodilator Response in Children with Asthma

RATIONALE

Stress is associated with asthma morbidity in Puerto Ricans (PRs), who have reduced bronchodilator response (BDR).

OBJECTIVES

To examine whether stress and/or a gene regulating anxiety (ADCYAP1R1) is associated with BDR in PR and non-PR children with asthma.

METHODS

This was a cross-sectional study of stress and BDR (percent change in FEV1 after BD) in 234 PRs ages 9-14 years with asthma. We assessed child stress using the Checklist of Children's Distress Symptoms, and maternal stress using the Perceived Stress Scale. Replication analyses were conducted in two cohorts. Polymorphisms in ADCYAP1R1 were genotyped in our study and six replication studies. Multivariable models of stress and BDR were adjusted for age, sex, income, environmental tobacco smoke, and use of inhaled corticosteroids.

MEASUREMENTS AND MAIN RESULTS

High child stress was associated with reduced BDR in three cohorts. PR children who were highly stressed (upper quartile, Checklist of Children's Distress Symptoms) and whose mothers had high stress (upper quartile, Perceived Stress Scale) had a BDR that was 10.2% (95% confidence interval, 6.1-14.2%) lower than children who had neither high stress nor a highly stressed mother. A polymorphism in ADCYAP1R1 (rs34548976) was associated with reduced BDR. This single-nucleotide polymorphism is associated with reduced expression of the gene for the β2-adrenergic receptor (ADRB2) in CD4(+) lymphocytes of subjects with asthma, and it affects brain connectivity of the amygdala and the insula (a biomarker of anxiety).

CONCLUSIONS

High child stress and an ADCYAP1R1 single-nucleotide polymorphism are associated with reduced BDR in children with asthma. This is likely caused by down-regulation of ADRB2 in highly stressed children.

Severe Asthma in Children

Severe asthma in children is associated with significant morbidity and is a highly heterogeneous disorder with multiple clinical phenotypes. Cluster analyses have been performed in several groups to explain some of the heterogeneity of pediatric severe asthma, which is reviewed in this article. The evaluation of a child with severe asthma includes a detailed diagnostic assessment and excluding other possible diagnoses and addressing poor control due to comorbidities, lack of adherence to asthma controller medications, poor technique, and other psychological and environmental factors. Children with severe asthma require significant resources including regular follow-up appointments with asthma education, written asthma action plan, and care by a multidisciplinary team. Management of pediatric severe asthma now includes emerging phenotypic-directed therapies; however, continued research is still needed to further study the long-term outcomes of pediatric severe asthma and its treatment.

Racial disparities in asthma-related health care use in the National Heart, Lung, and Blood Institute's Severe Asthma Research Program

BACKGROUND

Despite advances in asthma care, disparities persist. Black patients are disproportionally affected by asthma and also have poorer outcomes compared with white patients.

OBJECTIVE

We sought to determine associations between black and white patients and asthma-related health care use, accounting for complex relationships.

METHODS

This study was completed as part of the National Heart, Lung, and Blood Institute's Severe Asthma Research Program, a prospective observational cohort. Between November 2012 and February 2015, it enrolled 579 participants 6 years and older with 1 year of observation time and complete data. Inverse probability of treatment weighting was used to balance racial groups with respect to community and family socioeconomic variables and environmental exposure variables. The primary outcome was emergency department (ED) use for asthma. Secondary outcomes included inhaled corticosteroid use, outpatient physician's office visits for asthma, and asthma-related hospitalization.

RESULTS

Black patients had greater odds of ED use over 1 year (odds ratio, 2.19; 95% CI, 1.43-3.35) but also differed in the majority (>50%) of baseline variables measured. After statistical balancing of the racial groups, the difference between black and white patients with respect to ED use no longer reached the level of significance. Instead, in secondary analyses black patients were less likely to see an outpatient physician for asthma management (adjusted odds ratio, 0.57; 95% CI, 0.38-0.85).

CONCLUSIONS

The disparity in ED use was eliminated after consideration of multiple variables. Social and environmental policies and interventions tailored to black populations with a high burden of asthma are critical to reduction (or elimination) of these disparities.

Effects of endogenous sex hormones on lung function and symptom control in adolescents with asthma

BACKGROUND

Although pre-puberty asthma is more prevalent in males, after puberty through middle-age, asthma is more prevalent in females. The surge of sex hormones with puberty might explain this gender switch.

METHODS

To examine the effects of sex hormones on lung function and symptoms with puberty, Tanner stage was assessed in 187 children 6-18 years of age (59% severe) enrolled in the NIH/NHLBI Severe Asthma Research Program (SARP). The effects of circulating sex hormones (n = 68; testosterone, dehydroepiandrosterone sulfate (DHEA-S), estrogen, and progesterone) on lung function and 4 week symptom control (ACQ6) in cross-section were tested by linear regression.

RESULTS

From pre-/early to late puberty, lung function did not change significantly but ACQ6 scores improved in males with severe asthma. By contrast females had lower post-BD FEV₁% and FVC% and worse ACQ6 scores with late puberty assessed by breast development. In males log DHEA-S levels, which increased by Tanner stage, associated positively with pre- and post-BD FEV₁%, pre-BD FVC %, and negatively (improved) with ACQ6. Patients treated with high-dose inhaled corticosteroids had similar levels of circulating DHEA-S. In females, estradiol levels increased by Tanner stage, and associated negatively with pre-BD FEV₁% and FVC %.

CONCLUSIONS

These results support beneficial effects of androgens on lung function and symptom control and weak deleterious effects of estradiol on lung function in children with asthma. Longitudinal data are necessary to confirm these cross-sectional findings and to further elucidate hormonal mechanisms informing sex differences in asthma features with puberty.

TRIAL REGISTRATION

ClinicalTrials.gov registration number: NCT01748175 .

Income is an independent risk factor for worse asthma outcomes

BACKGROUND

Socioeconomic status (SES) is associated with asthma morbidity in observational studies, but the factors underlying this association are uncertain.

OBJECTIVE

We investigated whether 3 SES correlates-low income, low education, and high perceived stress-were independent risk factors for treatment failure and asthma exacerbations in the context of a randomized controlled trial.

METHODS

The effect of low SES (household income of <$50,000/y and household educational level of less than a Bachelor's degree) and high perceived stress (defined as a score of >20 on a perceived stress scale) on asthma morbidity was analyzed in 381 participants by using Poisson regression models. The primary outcome was treatment failure (defined in the trial protocol as a significant clinical or airflow deterioration), and the secondary outcome was asthma exacerbations requiring systemic corticosteroids.

RESULTS

Fifty-four percent of participants had a low income, 40% had a low educational level, and 17% had high perceived stress levels. Even after adjusting for race and other important confounders, participants with lower income had higher rates of both treatment failures (rate ratio, 1.6; 95% CI, 1.1-2.3; P = .03) and exacerbations (rate ratio, 1.9; 95% CI, 1.1-3.3; P = .02). Adherence with inhaled corticosteroids was similarly high for both income categories. Education and perceived stress were not significantly associated with either outcome.

CONCLUSIONS

In the context of a randomized controlled trial, participants with lower income were more likely to experience adverse asthma outcomes independent of education, perceived stress, race, and medication adherence.

Relationships among Maternal Stress and Depression, Type 2 Responses, and Recurrent Wheezing at Age 3 Years in Low-Income Urban Families

RATIONALE

Maternal depression and prenatal and early life stress may influence childhood wheezing illnesses, potentially through effects on immune development.

OBJECTIVES

To test the hypothesis that maternal stress and/or depression during pregnancy and early life are associated with recurrent wheezing and aeroallergen sensitivity and altered cytokine responses (enhanced type 2 or reduced virus-induced cytokine responses) from stimulated peripheral blood mononuclear cells at age 3 years.

METHODS

URECA (Urban Environment and Childhood Asthma) is a birth cohort at high risk for asthma (n = 560) in four inner cities. Maternal stress, depression, and childhood wheezing episodes were assessed by quarterly questionnaires beginning at birth. Logistic and linear regression techniques were used to examine the relation of maternal stress/depression to recurrent wheezing and peripheral blood mononuclear cell cytokine responses at age 3 years.

MEASUREMENTS AND MAIN RESULTS

Overall, 166 (36%) children had recurrent wheeze at age 3 years. Measures of maternal perceived stress at Years 2 and 3 were positively associated with recurrent wheeze (P < 0.05). Maternal depression (any year) was significantly associated with recurrent wheezing (P ≤ 0.01). These associations were also significant when considered in a longitudinal analysis of cumulative stress and depression (P ≤ 0.02). Neither stress nor depression was significantly related to aeroallergen sensitization or antiviral responses. Contrary to our original hypothesis, prenatal and Year 1 stress and depression had significant inverse associations with several type 2 cytokine responses.

CONCLUSIONS

In urban children at high risk for asthma, maternal perceived stress and depression were significantly associated with recurrent wheezing but not increased atopy or reduced antiviral responses.

Endotype of allergic asthma with airway obstruction in urban children

BACKGROUND

Black and Hispanic children growing up in disadvantaged urban neighborhoods have the highest rates of asthma and related morbidity in the United States.

OBJECTIVES

This study sought to identify specific respiratory phenotypes of health and disease in this population, associations with early life exposures, and molecular patterns of gene expression in nasal epithelial cells that underlie clinical disease.

METHODS

The study population consisted of 442 high-risk urban children who had repeated assessments of wheezing, allergen-specific IgE, and lung function through 10 years of age. Phenotypes were identified by developing temporal trajectories for these data, and then compared to early life exposures and patterns of nasal epithelial gene expression at 11 years of age.

RESULTS

Of the 6 identified respiratory phenotypes, a high wheeze, high atopy, low lung function group had the greatest respiratory morbidity. In early life, this group had low exposure to common allergens and high exposure to ergosterol in house dust. While all high-atopy groups were associated with increased expression of a type-2 inflammation gene module in nasal epithelial samples, an epithelium IL-13 response module tracked closely with impaired lung function, and a MUC5AC hypersecretion module was uniquely upregulated in the high wheeze, high atopy, low lung function group. In contrast, a medium wheeze, low atopy group showed altered expression of modules of epithelial integrity, epithelial injury, and antioxidant pathways.

CONCLUSIONS

In the first decade of life, high-risk urban children develop distinct phenotypes of respiratory health versus disease that link early life environmental exposures to childhood allergic sensitization and asthma. Moreover, unique patterns of airway gene expression demonstrate how specific molecular pathways underlie distinct respiratory phenotypes, including allergic and nonallergic asthma.

Exposure to gun violence and asthma among children in Puerto Rico

BACKGROUND AND OBJECTIVES

Although community violence may influence asthma morbidity by increasing stress, no study has assessed exposure to gun violence and childhood asthma. We examined whether exposure to gun violence is associated with asthma in children, particularly in those reporting fear of leaving their home.

METHODS

Case-control study of 466 children aged 9-14 years with (n = 234) and without (n = 232) asthma in San Juan, Puerto Rico. Lifetime exposure to gun violence was defined as hearing a gunshot more than once. We also assessed whether the child was afraid to leave his/her home because of violence. Asthma was defined as physician-diagnosed asthma and wheeze in the prior year. We used logistic regression for the statistical analysis. All multivariate models were adjusted for age, gender, household income, parental asthma, environmental tobacco smoke, prematurity and residential distance from a major road.

RESULTS

Cases were more likely to have heard a gunshot more than once than control subjects (n = 156 or 67.2% vs. n = 122 or 52.1%, P < 0.01). In a multivariate analysis, hearing a gunshot more than once was associated with asthma (odds ratio [OR] = 1.8, 95% confidence interval [CI] = 1.1-1.7, P = 0.01). Compared with children who had heard a gunshot not more than once and were not afraid to leave their home because of violence, those who had heard a gunshot more than once and were afraid to leave their home due to violence had 3.2 times greater odds of asthma (95% CI for OR = 2.2-4.4, P < 0.01).

CONCLUSIONS

Exposure to gun violence is associated with asthma in Puerto Rican children, particularly in those afraid to leave their home. Stress from such violence may contribute to the high burden of asthma in Puerto Ricans.

Parental numeracy and asthma exacerbations in Puerto Rican children

BACKGROUND

Puerto Ricans share a disproportionate burden of childhood asthma in the United States. Little is known about the impact of low parental numeracy (a health literacy skill) on asthma morbidity in Puerto Rican children. Our objective was to examine whether low parental numeracy is associated with increased asthma morbidity in Puerto Rican children.

METHODS

This was a cross-sectional study of 351 children with asthma, aged 6 to 14 years, living in San Juan, Puerto Rico. Parents of study participants completed a modified version of the Asthma Numeracy Questionnaire. Multivariate linear or logistic regression was used to examine the relation between low parental numeracy (defined as no correct answers in the modified Asthma Numeracy Questionnaire) and indicators of asthma morbidity (severe asthma exacerbations, core measures of asthma exacerbations, and lung function measures). All multivariate models were adjusted for age, sex, household income, reported use of inhaled corticosteroids in the previous 6 months, and exposure to secondhand tobacco smoke.

RESULTS

Low parental numeracy was associated with increased odds of visits to the ED or urgent care for asthma (adjusted OR [aOR]=1.7, 95% CI=1.03-2.7, P=.04). The association between low parental numeracy and hospitalizations for asthma was significant only among children not using inhaled corticosteroids (aOR=2.8, 95% CI=1.4-5.6, P=.004). There was no association between low parental numeracy and use of systemic steroids or lung function measures.

CONCLUSIONS

Low parental numeracy is associated with increased asthma morbidity in Puerto Rican children.

Determinants of lung function across childhood in the Severe Asthma Research Program (SARP) 3

BACKGROUND

Children with asthma are at risk for low lung function extending into adulthood, but understanding of clinical predictors is incomplete.

OBJECTIVE

We sought to determine phenotypic factors associated with FEV1 throughout childhood in the Severe Asthma Research Program 3 pediatric cohort.

METHODS

Lung function was measured at baseline and annually. Multivariate linear mixed-effects models were constructed to assess the effect of baseline and time-varying predictors of prebronchodilator FEV1 at each assessment for up to 6 years. All models were adjusted for age, predicted FEV1 by Global Lung Function Initiative reference equations, race, sex, and height. Secondary outcomes included postbronchodilator FEV1 and prebronchodilator FEV1/forced vital capacity.

RESULTS

A total of 862 spirometry assessments were performed for 188 participants. Factors associated with FEV1 include baseline Feno (B, -49 mL/log2 PPB; 95% CI, -92 to -6), response to a characterizing dose of triamcinolone acetonide (B, -8.4 mL/1% change FEV1 posttriamcinolone; 95% CI, -12.3 to -4.5), and maximal bronchodilator reversibility (B, -27 mL/1% change postbronchodilator FEV1; 95% CI, -37 to -16). Annually assessed time-varying factors of age, obesity, and exacerbation frequency predicted FEV1 over time. Notably, there was a significant age and sex interaction. Among girls, there was no exacerbation effect. For boys, however, moderate (1-2) exacerbation frequency in the previous 12 months was associated with -20 mL (95% CI, -39 to -2) FEV1 at each successive year. High exacerbation frequency (≥3) 12 to 24 months before assessment was associated with -34 mL (95% CI, -61 to -7) FEV1 at each successive year.

CONCLUSIONS

In children with severe and nonsevere asthma, several clinically relevant factors predict FEV1 over time. Boys with recurrent exacerbations are at high risk of lower FEV1 through childhood.

Maternal stress and depression are associated with respiratory phenotypes in urban children

BACKGROUND

Prenatal and early-life exposure to maternal stress and depression is linked to development of recurrent wheezing in young children.

OBJECTIVE

We sought to determine whether maternal stress and depression in early life are associated with nonatopic wheezing phenotype in urban children.

METHODS

The Urban Environment and Childhood Asthma Study examined a birth cohort of children at high risk for asthma in low-income neighborhoods. Prenatal and postnatal (through age 3 years) maternal stress and depression scores were compared with respiratory phenotypes through age 10 years (multinomial regression), self-reported colds (linear regression), and detection of respiratory viruses (Poisson regression).

RESULTS

Scores for maternal depression, and, to a lesser extent, maternal perceived stress, were positively related to multiple wheezing phenotypes. In particular, cumulative measures of maternal depression in the first 3 years were related to the moderate-wheeze-low-atopy phenotype (odds ratio, 1.13; [1.05, 1.21]; P < .01). Considering indicators of respiratory health that were used to identify the phenotypes, there were multiple positive associations between early-life scores for maternal stress and depression and increased wheezing illnesses, but no consistent relationships with lung function and some inverse relationships with allergic sensitization. Cumulative maternal stress and depression scores were associated with cumulative number of respiratory illnesses through age 3 years.

CONCLUSIONS

Among high-risk, urban children, maternal stress and depression in early life were positively associated with respiratory illnesses and a moderate-wheeze-low-atopy phenotype. These results suggest that treating stress and depression in expectant and new mothers could reduce viral respiratory illnesses and recurrent wheeze during the preschool years and some forms of childhood asthma.

Exacerbation-prone asthma in the context of race and ancestry in Asthma Clinical Research Network trials

BACKGROUND

Minority groups of African descent experience disproportionately greater asthma morbidity compared with other racial groups, suggesting that genetic variation from a common ancestry could influence exacerbation risk.

OBJECTIVE

We evaluated clinical trial measures in the context of self-reported race and genetic ancestry to identify risk factors for asthma exacerbations.

METHODS

One thousand eight hundred forty multiethnic subjects from 12 Asthma Clinical Research Network and AsthmaNet trials were analyzed for incident asthma exacerbations with Poisson regression models that included clinical measures, self-reported race (black, non-Hispanic white, and other), and estimates of global genetic African ancestry in a subgroup (n = 760).

RESULTS

Twenty-four percent of 1840 subjects self-identified as black. Black and white subjects had common risk factors for exacerbations, including a history of 2 or more exacerbations in the previous year and FEV₁ percent predicted values, whereas chronic sinusitis, allergic rhinitis, and gastroesophageal reflux disease were only associated with increased exacerbation risk in black subjects. In the combined multiethnic cohort, neither race (P = .30) nor percentage of genetic African ancestry as a continuous variable associated with exacerbation risk (adjusted rate ratio [RR], 1.26 [95% CI, 0.94-1.70; P = .13]; RR per 1-SD change [32% ancestry], 0.97 [95% CI, 0.78-1.19; P = .74]). However, in 161 black subjects with genetic data, those with African ancestry greater than the median (≥82%) had a significantly greater risk of exacerbation (RR, 3.06 [95% CI, 1.09-8.6; P = .03]).

CONCLUSION

Black subjects have unique risk factors for asthma exacerbations, of which global African genetic ancestry had the strongest effect.

Variation in asthma care at hospital discharge by race/ethnicity groups

Objective: While asthma disproportionately affects minorities, little is known about racial/ethnic differences in asthma care at hospital discharge. Methods: Secondary data analysis of multicenter retrospective study using standardized medical record review. A random sample of patients aged 2-54 years, who were hospitalized for asthma at 25 hospitals from 2012 to 2013 was analyzed. We categorized patients into three race/ethnicity groups: non-Hispanic white (NHW), non-Hispanic black (NHB), and Hispanic. Multivariable logistic regression using generalized estimating equations was used to examine the relationship between race/ethnicity and the provision of guideline-concordant asthma care at hospital discharge including: the provision of asthma action plans, provision of new prescription of an inhaled corticosteroid, and referral to an asthma specialist. Results: Nine hundred thirteen patients (39% children, 71% minorities) hospitalized for asthma were included. In adjusted models, NHB children were significantly less likely to receive a written asthma action plan (OR 0.48; 95% CI 0.31-0.76) than NHW children. In contrast, among adults, we found no statistically significant difference in the provision of asthma action plan. Additionally, we found no difference in the provision of a new inhaled corticosteroid prescription or referral to an asthma specialist among children or adults. Conclusions: NHB and Hispanic patients represent the majority of patients hospitalized for acute asthma in our cohort and were more likely than NHW patients to have increased markers of asthma severity. Despite this, the only significant racial/ethnic difference in asthma care at hospital discharge was among NHB children, who were less likely to receive a written asthma action plan .

Clinical significance of the bronchodilator response in children with severe asthma

BACKGROUND

Our objective was to determine those characteristics associated with reversibility of airflow obstruction and response to maximal bronchodilation in children with severe asthma through the Severe Asthma Research Program (SARP).

METHODS

We performed a cross-sectional analysis evaluating children ages 6 to 17 years with nonsevere asthma (NSA) and severe asthma (SA). Participants underwent spirometry before and after 180 µg of albuterol to determine reversibility (≥12% increase in FEV₁ ). Participants were then given escalating doses up to 720 µg of albuterol to determine their maximum reversibility.

RESULTS

We evaluated 230 children (n = 129 SA, n = 101 NSA) from five centers across the United States in the SARP I and II cohorts. SA (odds ratio [OR], 2.08, 95% confidence interval [CI], 1.05-4.13), second-hand smoke exposure (OR, 2.81, 95%CI, 1.23-6.43), and fractional exhaled nitric oxide (FeNO; OR, 1.97, 95%CI, 1.35-2.87) were associated with increased odds of airway reversibility after maximal bronchodilation, while higher prebronchodilator (BD) FEV₁ % predicted (OR, 0.91, 95%CI, 0.88-0.94) was associated with decreased odds. In an analysis using the SARP III cohort (n = 186), blood neutrophils, immunoglobulin E (IgE), and FEV₁ % predicted were significantly associated with BD reversibility. In addition, children with BD response have greater healthcare utilization. BD reversibility was associated with reduced lung function at enrollment and 1-year follow-up though less decline in lung function over 1 year compared to those without reversibility.

CONCLUSIONS

Lung function, that is FEV₁ % predicted, is a predictor of BD response in children with asthma. Additionally, smoke exposure, higher FeNO or IgE level, and low peripheral blood neutrophils are associated with a greater likelihood of BD reversibility. BD response can identify a phenotype of pediatric asthma associated with low lung function and poor asthma control.

Early-Life Exposure to Air Pollution and Childhood Asthma Cumulative Incidence in the ECHO CREW Consortium

Importance

Exposure to outdoor air pollution contributes to childhood asthma development, but many studies lack the geographic, racial and ethnic, and socioeconomic diversity to evaluate susceptibility by individual-level and community-level contextual factors.

Objective

To examine early life exposure to fine particulate matter (PM2.5) and nitrogen oxide (NO2) air pollution and asthma risk by early and middle childhood, and whether individual and community-level characteristics modify associations between air pollution exposure and asthma.

Design, Setting, and Participants

This cohort study included children enrolled in cohorts participating in the Children's Respiratory and Environmental Workgroup consortium. The birth cohorts were located throughout the US, recruited between 1987 and 2007, and followed up through age 11 years. The survival analysis was adjusted for mother's education, parental asthma, smoking during pregnancy, child's race and ethnicity, sex, neighborhood characteristics, and cohort. Statistical analysis was performed from February 2022 to December 2023.

Exposure

Early-life exposures to PM2.5 and NO2 according to participants' birth address.

Main Outcomes and Measures

Caregiver report of physician-diagnosed asthma through early (age 4 years) and middle (age 11 years) childhood.

Results

Among 5279 children included, 1659 (31.4%) were Black, 835 (15.8%) were Hispanic, 2555 (48.4%) where White, and 229 (4.3%) were other race or ethnicity; 2721 (51.5%) were male and 2596 (49.2%) were female; 1305 children (24.7%) had asthma by 11 years of age and 954 (18.1%) had asthma by 4 years of age. Mean values of pollutants over the first 3 years of life were associated with asthma incidence. A 1 IQR increase in NO2 (6.1 μg/m3) was associated with increased asthma incidence among children younger than 5 years (HR, 1.25 [95% CI, 1.03-1.52]) and children younger than 11 years (HR, 1.22 [95% CI, 1.04-1.44]). A 1 IQR increase in PM2.5 (3.4 μg/m3) was associated with increased asthma incidence among children younger than 5 years (HR, 1.31 [95% CI, 1.04-1.66]) and children younger than 11 years (OR, 1.23 [95% CI, 1.01-1.50]). Associations of PM2.5 or NO2 with asthma were increased when mothers had less than a high school diploma, among Black children, in communities with fewer child opportunities, and in census tracts with higher percentage Black population and population density; for example, there was a significantly higher association between PM2.5 and asthma incidence by younger than 5 years of age in Black children (HR, 1.60 [95% CI, 1.15-2.22]) compared with White children (HR, 1.17 [95% CI, 0.90-1.52]).

Conclusions and Relevance

In this cohort study, early life air pollution was associated with increased asthma incidence by early and middle childhood, with higher risk among minoritized families living in urban communities characterized by fewer opportunities and resources and multiple environmental coexposures. Reducing asthma risk in the US requires air pollution regulation and reduction combined with greater environmental, educational, and health equity at the community level.

Clinical and molecular analysis of longitudinal rhinitis phenotypes in an urban birth cohort

BACKGROUND

Chronic rhinitis symptoms cause significant health burden among children and can have a heterogeneous presentation. Defining phenotypes of childhood chronic rhinitis and associated pathobiology may lead to prevention or improved treatments.

OBJECTIVES

We sought to identify longitudinal patterns of rhinitis symptoms in childhood and determine their associations with early life risk factors, allergic comorbidities, and nasal epithelial cell gene expression.

METHODS

Chronic rhinitis symptoms were evaluated from ages 1 through 11 years in 485 urban children at high risk for allergic disease in the URECA (Urban Environment and Childhood Asthma) birth cohort. We identified longitudinal rhinitis phenotypes and their relationships to early life exposures, atopic comorbidities, and patterns of nasal epithelial gene expression at age 11 years.

RESULTS

Chronic rhinitis symptoms started early in many children and were a risk factor for developing aeroallergen sensitization. We identified 4 longitudinal rhinitis phenotypes: low/minimal, persistent, persistent decreasing, and late increasing. Persistent rhinitis was most closely linked to allergic sensitization and asthma. Risk factors for persistent rhinitis included frequent colds (P < .001), antibiotic use (P < .001), and reduced exposure to common indoor aeroallergens (P = .003). Compared to low/minimal rhinitis phenotype, the other rhinitis phenotypes were associated with increased expression of canonical type 2 genes and decreased expression of immune response genes.

CONCLUSIONS

In urban children, rhinitis symptoms often precede aeroallergen sensitization. Rhinitis phenotypes based on symptoms had distinct risk factors and nasal transcriptome. These results suggest that focusing on early life risk factors and distinct immune mechanisms may be a target to preventing chronic rhinitis in childhood.

The Legacy of Redlining: Increasing Childhood Asthma Disparities through Neighborhood Poverty

Rationale: Identifying the root causes of racial disparities in childhood asthma is critical for health equity. Objectives: To determine whether the racist policy of redlining in the 1930s led to present-day disparities in childhood asthma by increasing community-level poverty and decreasing neighborhood socioeconomic position (SEP). Methods: We categorized census tracts at the birth address of participants from the Children's Respiratory and Environmental Workgroup birth cohort consortium into categories A, B, C, and D as defined by the Home Owners Loan Corporation, with D being the highest perceived risk. Surrogates of present-day neighborhood-level SEP were determined for each tract, including the percentage of low-income households, the CDC's Social Vulnerability Index, and other tract-level variables. We performed causal mediation analysis, which, under the assumption of no unmeasured confounding, estimates the direct and mediated pathways by which redlining may cause asthma disparities through tract-level mediators adjusting for individual-level covariates. Measurements and Main Results: Of 4,849 children, the cumulative incidence of asthma through age 11 was 26.6%, and 13.2% resided in census tracts with a Home Owners Loan Corporation grade of D. In mediation analyses, residing in Grade-D tracts (adjusted odds ratio = 1.03 [95% confidence interval = 1.01, 1.05]) was significantly associated with childhood asthma, with 79% of this increased risk mediated by percentage of low-income households; results were similar for the Social Vulnerability Index and other tract-level variables. Conclusions: The historical structural racist policy of redlining led to present-day asthma disparities in part through decreased neighborhood SEP. Policies aimed at reversing the effects of structural racism should be considered to create more just, equitable, and healthy communities.