Air pollution, urgent asthma medical visits and the modifying effect of neighborhood asthma prevalence.

Background: Social and environmental stressors may modify associations between environmental pollutants and asthma symptoms. We examined if neighborhood asthma prevalence (higher: HAPN vs. lower: LAPN), a surrogate for underlying risk factors for asthma, modified the relationship between pollutants and urgent asthma visits.

Infant rhinitis and watery eyes predict school-age exercise-induced wheeze, emergency department visits and respiratory-related hospitalizations.

Background: Rhinitis and conjunctivitis are often linked to asthma development through an allergic pathway. However, runny nose and watery eyes can result from nonallergic mechanisms. These mechanisms can also underlie exercise-induced wheeze (EIW), which has been associated with urgent medical visits for asthma, independent of other indicators of asthma severity or control.

Allergic sensitization patterns identified through latent class analysis among children with and without asthma.

Background: Specific patterns of allergic sensitization to common allergens may provide relevant clinical insight into asthma risk.

Objective: To identify patterns of allergic sensitization based on multiple individual allergens and link these to current and persistent asthma using baseline and 3-year follow-up data.

Methods: Children 7 to 8 years old with (n = 196) and without (n = 136) asthma from the New York City Neighborhood Asthma and Allergy Study were studied.

Domestic airborne black carbon levels and 8-isoprostane in exhaled breath condensate among children in New York City.

Background: Exposure to airborne black carbon (BC) has been associated with asthma development, respiratory symptoms and decrements in lung function. However, the mechanism through which BC may lead to respiratory symptoms has not been completely elucidated. Oxidative stress has been suggested as a potential mechanism through which BC might lead to adverse health outcomes.

Early-life cockroach allergen and polycyclic aromatic hydrocarbon exposures predict cockroach sensitization among inner-city children.

Background: Sensitization to cockroach is one of the strongest identified risk factors for greater asthma morbidity in low-income urban communities; however, the timing of exposures relevant to the development of sensitization has not been elucidated fully. Furthermore, exposure to combustion byproducts, including polycyclic aromatic hydrocarbons (PAHs), can augment the development of allergic sensitization.

Objective: We sought to test the hypotheses that domestic cockroach allergen measured prenatally would predict cockroach sensitization in early childhood and that this association would be greater for children exposed to higher PAH concentrations.

Exercise-induced wheeze, urgent medical visits, and neighborhood asthma prevalence.

Objective: Exercise-induced wheeze (EIW) may identify a distinct population among asthmatics and give insight into asthma morbidity etiology. The prevalence of pediatric asthma and associated urgent medical visits varies greatly by neighborhood in New York City and is highest in low-income neighborhoods. Although increased asthma severity might contribute to the disparities in urgent medical visits, when controlling for health insurance coverage, we previously observed no differences in clinical measures of severity between asthmatic children living in neighborhoods with lower (3%-9%) versus higher (11%-19%) asthma prevalence.

Children's urinary phthalate metabolites and fractional exhaled nitric oxide in an urban cohort.

Rationale: Phthalates are used widely in consumer products. Exposure to several phthalates has been associated with respiratory symptoms and decreased lung function. Associations between children's phthalate exposures and fractional exhaled nitric oxide (Fe(NO)), a biomarker of airway inflammation, have not been examined.

Prenatal exposure to butylbenzyl phthalate and early eczema in an urban cohort.

Background: Recent cross-sectional studies suggest a link between butylbenzyl phthalate (BBzP) in house dust and childhood eczema.

Objectives: We aimed to evaluate whether concentrations of monobenzyl phthalate (MBzP), the main BBzP metabolite in urine, during pregnancy are associated prospectively with eczema in young children, and whether this association varies by the child's sensitization to indoor allergens or serological evidence of any allergies.

Methods: MBzP was measured in spot urine samples during the third trimester of pregnancy from 407 African-American and Dominican women residing in New York City in 1999-2006.

Using latent class growth analysis to identify childhood wheeze phenotypes in an urban birth cohort.

Background: To advance asthma cohort research, we need a method that can use longitudinal data, including when collected at irregular intervals, to model multiple phenotypes of wheeze and identify both time-invariant (eg, sex) and time-varying (eg, environmental exposure) risk factors.

Objective: To demonstrate the use of latent class growth analysis (LCGA) in defining phenotypes of wheeze and examining the effects of causative factors, using repeated questionnaires in an urban birth cohort study.

Methods: We gathered repeat questionnaire data on wheeze from 689 children ages 3 through 108 months (n = 7,048 questionnaires) and used LCGA to identify wheeze phenotypes and model the effects of time-invariant (maternal asthma, ethnicity, prenatal environmental tobacco smoke, and child sex) and time-varying (cold/influenza [flu] season) risk factors on prevalence of wheeze in each phenotype.

Domestic airborne black carbon and exhaled nitric oxide in children in NYC.

Differential exposure to combustion by-products and allergens may partially explain the marked disparity in asthma prevalence (3-18%) among New York City neighborhoods. Subclinical changes in airway inflammation can be measured by fractional exhaled nitric oxide (FeNO). FeNO could be used to test independent effects of these environmental exposures on airway inflammation.

Neighborhood differences in exposure and sensitization to cockroach, mouse, dust mite, cat, and dog allergens in New York City.

Background: Asthma prevalence varies widely among neighborhoods within New York City. Exposure to mouse and cockroach allergens has been suggested as a cause.

Objective: To test the hypotheses that children living in high asthma prevalence neighborhoods (HAPNs) would have higher concentrations of cockroach and mouse allergens in their homes than children in low asthma prevalence neighborhoods (LAPNs), and that these exposures would be related to sensitization and asthma.

Exhaled NO among inner-city children in New York City.

Background: Fractional exhaled nitric oxide (FeNO) has been proposed as a biomarker of airway inflammation for cohort studies of asthma.

Objectives: To assess the association between FeNO and asthma symptoms among 7-year-old children living in an inner-city community. To test the association between environmental tobacco smoke (ETS) exposure (previous and current) and FeNO among these children.

Asthma, allergy, and IgE levels in NYC head start children.

Background: Among preschool-age children in New York City neighborhoods with high asthma hospitalization rates, we analyzed the associations of total immunoglobulin E (IgE), specific IgE to common indoor allergens, and allergy symptoms with asthma.

Methods: Parents of children in New York City Head Start programs were asked to complete a questionnaire covering demographic factors, health history (including respiratory conditions), lifestyle, and home environment. Children's serum samples were analyzed for total IgE and specific IgE antibodies to cockroach, dust mite, mouse, and cat allergens by immunoassay.

Physical activity and asthma symptoms among New York City Head Start Children.

The coincidence of both an obesity epidemic and an asthma epidemic among children in the United States has suggested that childhood overweight and sedentary lifestyles may be risk factors for asthma development. We therefore conducted a study of those factors among children enrolled in Head Start Centers located in areas of New York City with high asthma hospitalization rates. Data were gathered from 547 children through an intensive home visit, and physical activity was measured on 463 children using the Actiwatch accelerometer.

Prenatal acetaminophen exposure and risk of wheeze at age 5 years in an urban low-income cohort.

Background: Acetaminophen has been associated with asthma and is in part metabolised via the glutathione pathway. Inner-city minority children have high asthma morbidity and a relatively high frequency of a minor allele variant in the glutathione S transferase Pi gene (GSTP1). We hypothesised that prenatal acetaminophen exposure would predict wheeze at age 5 years in an inner-city minority cohort and examined whether this association was modified by common polymorphisms in genes related to the glutathione pathway.

Effects of winter birth season and prenatal cockroach and mouse allergen exposure on indoor allergen-specific cord blood mononuclear cell proliferation and cytokine production.

Background: Season of birth has been associated with the development of atopy and asthma. Relationships among a particular birth season, maternal allergen exposure during the birth season, and childhood development of allergies to allergens in higher concentration during the birth season may be important.

Objective: To investigate the effects of winter birth (January 1 to March 31) and prenatal cockroach and mouse allergens in settled dust on indoor allergen-specific cord blood mononuclear cell (CBMC) proliferation, TH2 production, and cord blood IgE concentration.

Total and specific IgE associations between New York City Head Start children and their parents.

Background: Allergy and asthma risk share strong inherited components; however, the relative importance of maternal and paternal atopy in predicting child atopy remain unclear.

Objective: We sought to identify relationships between parents' and children's total and specific IgE levels within family units as predictors of allergic risk in children.

Methods: Total and allergen-specific IgE (to dust mite, cockroach, mouse, and cat) were determined by means of ImmunoCap (Phadia, Inc, Portage, Mich) in a sample of families participating in New York City Head Start programs.

Early respiratory infections and asthma among New York City Head Start children.

Background: Respiratory infections in neonates have been found to predict wheeze among young children. We hypothesized that among preschool children from low-income minority communities in New York City, current asthma would be associated with a history of respiratory infection in the first few months after their birth.

Methods: We asked parents of children in New York City Head Start centers (preschool programs for children of low-income families) to respond to a questionnaire covering demographic factors, lifestyle, home environment, and health history, including a detailed history of respiratory conditions.

Cat ownership is a risk factor for the development of anti-cat IgE but not current wheeze at age 5 years in an inner-city cohort.

Background: Cat ownership is inversely associated with atopy and asthma in some areas of the world, but the relevance of cat ownership to allergic disease in the inner city is less known.

Objective: We sought to evaluate the relationship between cat ownership and the development of early sensitization and wheeze.

Methods: By using a prospective birth cohort study, Dominican and African American mothers living in New York City underwent repeated questionnaires about their child from birth to age 5 years.

Cockroach allergen levels and associations with cockroach-specific IgE.

Background: Among inner-city children with asthma, cockroach allergen exposure has been associated with allergic sensitization.

Objective: We hypothesized that cockroach allergen levels in homes would be associated with sensitization to cockroach allergens in children.

Methods: From a low-income preschool program, 341 four-year-old children selected on the basis of the willingness of their caregivers to participate in the study were enrolled.

Endotoxin in inner-city homes: associations with wheeze and eczema in early childhood.

Background: An inverse association between domestic exposure to endotoxin and atopy in childhood has been observed. The relevance of this aspect of the hygiene hypothesis to US inner-city communities that have disproportionately high asthma prevalence has not been determined.

Objectives: To measure endotoxin in the dust from inner-city homes, evaluate associations between endotoxin and housing/lifestyle characteristics, and determine whether endotoxin exposure predicted wheeze, allergic rhinitis, and eczema over the first 3 years of life.

Prevalence of allergy symptoms and total IgE in a New York City cohort and their association with birth order.

Background: An inverse association between birth order and allergic disease has been widely observed, but has not been examined in the high asthma prevalence, inner-city populations of the United States. As part of an ongoing prospective birth cohort study, the prevalence of early phenotypes of asthma and/or allergy was compared with those reported in other studies, and the association with birth order was evaluated.

Methods: Children of Dominican and African-American mothers living in Northern Manhattan underwent detailed periodic questionnaires.