Trajectory analysis of rhinitis in a birth cohort from lower-income New York City neighborhoods.

BACKGROUND: Rhinitis is a prevalent, chronic nasal condition associated with asthma. However, its developmental trajectories remain poorly characterized. OBJECTIVE: We sought to describe the course of rhinitis from infancy to adolescence and the association between identified phenotypes, asthma-related symptoms, and physician-diagnosed asthma. METHODS: We collected rhinitis data from questionnaires repeated across 22 time points among 688 children from infancy to age 11 years and used latent class mixed modeling (LCMM) to identify phenotypes. Once children were between ages 5 and 12, a study physician determined asthma diagnosis. We collected information on the following asthma symptoms: any wheeze, exercise-induced wheeze, nighttime coughing, and emergency department visits. For each, we used LCMM to identify symptom phenotypes. Using logistic regression, we described the association between rhinitis phenotype and asthma diagnosis and each symptom overall and stratified by atopic predisposition and sex. RESULTS: LCMM identified 5 rhinitis trajectory groups: never/infrequent; transient; late onset, infrequent; late onset, frequent; and persistent. LCMM identified 2 trajectories for each symptom, classified as frequent and never/infrequent. Participants with persistent and late onset, frequent phenotypes were more likely to be diagnosed with asthma and to have the frequent phenotype for all symptoms (P < .01). We identified interaction between seroatopy and rhinitis phenotype for physician-diagnosed asthma (P = .04) and exercise-induced wheeze (P = .08). Severe seroatopy was more common among children with late onset, frequent and persistent rhinitis, with nearly 25% of these 2 groups exhibiting sensitivity to 4 or 5 of the 5 allergens tested. CONCLUSIONS: In this prospective, population-based birth cohort, persistent and late onset, frequent rhinitis phenotypes were associated with increased risk of asthma diagnosis and symptoms during adolescence.

Home and school pollutant exposure, respiratory outcomes, and influence of historical redlining.

BACKGROUND: The discriminatory and racist policy of historical redlining in the United States during the 1930s played a role in perpetuating contemporary environmental health disparities. OBJECTIVE: Our objectives were to determine associations between home and school pollutant exposure (fine particulate matter [PM2.5], NO2) and respiratory outcomes (Composite Asthma Severity Index, lung function) among school-aged children with asthma and examine whether associations differed between children who resided and/or attended school in historically redlined compared to non-redlined neighborhoods. METHODS: Children ages 6 to 17 with moderate-to-severe asthma (N = 240) from 9 US cities were included. Combined home and school exposure to PM2.5 and NO2 was calculated based on geospatially assessed monthly averaged outdoor pollutant concentrations. Repeated measures of Composite Asthma Severity Index and lung function were collected. RESULTS: Overall, 37.5% of children resided and/or attended schools in historically redlined neighborhoods. Children in historically redlined neighborhoods had greater exposure to NO2 (median: 15.4 vs 12.1 parts per billion) and closer distance to a highway (median: 0.86 vs 1.23 km), compared to those in non-redlined neighborhoods (P < .01). Overall, PM2.5 was not associated with asthma severity or lung function. However, among children in redlined neighborhoods, higher PM2.5 was associated with worse asthma severity (P < .005). No association was observed between pollutants and lung function or asthma severity among children in non-redlined neighborhoods (P > .005). CONCLUSIONS: Our findings highlight the significance of historical redlining and current environmental health disparities among school-aged children with asthma, specifically, the environmental injustice of PM2.5 exposure and its associations with respiratory health.

Rhinorrhea and watery eyes in infancy and risk of attention-deficit hyperactivity disorder in school-age children.

Increased parasympathetic nervous system (PNS) activity is associated with attention-deficit/hyperactivity disorder (ADHD) inattentive symptoms, but not hyperactive-impulsive symptoms, and may contribute to inattentive subtype etiology. Guided by prior work linking infant rhinorrhea and watery eyes without a cold (RWWC) to PNS dysregulation, we examined associations between infant RWWC and childhood ADHD symptoms in a longitudinal cohort of Black and Latinx children living in the context of economic disadvantage (N = 301 youth: 158 females, 143 males). Infant RWWC predicted higher inattentive (relative risk [RR] 2.16, p < .001) but not hyperactive-impulsive (RR 1.53, p = .065) ADHD symptoms (DuPaul scale), administered to caregivers at child age 8-14 years. Stratified analyses revealed that these associations were present in females but not males, who were three times more likely to have higher ADHD current total symptoms if they had infant RWWC than if they did not. Additionally, associations between RWWC and inattention symptoms were observed only in females. RWWC may thus serve as a novel risk marker of ADHD inattentive-type symptoms, especially for females.

Fungal diversity in homes and asthma morbidity among school-age children in New York City.

BACKGROUND: Asthma development has been inversely associated with exposure to fungal diversity. However, the influence of fungi on measures of asthma morbidity is not well understood. OBJECTIVES: This study aimed to test the hypothesis that fungal diversity is inversely associated with neighborhood asthma prevalence and identify specific fungal species associated with asthma morbidity. METHODS: Children aged 7-8 years (n = 347) living in higher (11-18%) and lower (3-9%) asthma prevalence neighborhoods were recruited within an asthma case-control study. Fungal communities were analyzed from floor dust using high-throughput DNA sequencing. A subset of asthmatic children (n = 140) was followed to age 10-11 to determine asthma persistence. RESULTS: Neighborhood asthma prevalence was inversely associated with fungal species richness (P = 0.010) and Shannon diversity (P = 0.059). Associations between neighborhood asthma prevalence and diversity indices were driven by differences in building type and presence of bedroom carpet. Among children with asthma at age 7-8 years, Shannon fungal diversity was inversely associated with frequent asthma symptoms at that age (OR 0.57, P = 0.025) and with asthma persistence to age 10-11 (OR 0.48, P = 0.043). Analyses of individual fungal species did not show significant associations with asthma outcomes when adjusted for false discovery rates. DISCUSSION: Lower fungal diversity was associated with asthma symptoms in this urban setting. Individual fungal species associated with asthma morbidity were not detected. Further research is warranted into building type, carpeting, and other environmental characteristics which influence fungal exposures in homes.

α-Gal specific-IgE prevalence and levels in Ecuador and Kenya: Relation to diet, parasites, and IgG4.

BACKGROUND: IgE to α-Gal is a cause of mammalian meat allergy and has been linked to tick bites in North America, Australia, and Eurasia. Reports from the developing world indicate that α-Gal sensitization is prevalent but has been little investigated. OBJECTIVE: We sought evidence for the cause(s) of α-Gal sensitization and lack of reported meat allergy among children in less developed settings in Ecuador and Kenya. METHODS: IgE to α-Gal and total IgE were assessed in children from Ecuador (n = 599) and Kenya (n = 254) and compared with children with (n = 42) and without known (n = 63) mammalian meat allergy from the southeastern United States. Information on diet, potential risk factors, and helminth infections was available for children from Ecuador. IgG4 to α-Gal and antibodies to regionally representative parasites were assessed in a subset of children. RESULTS: In Ecuador (32%) and Kenya (54%), α-Gal specific IgE was prevalent, but levels were lower than in children with meat allergy from the United States. Sensitization was associated with rural living, antibody markers of Ascaris exposure, and total IgE, but not active infections with Ascaris or Trichuris species. In Ecuador, 87.5% reported consuming beef at least once per week, including 83.9% of those who had α-Gal specific IgE. Levels of α-Gal specific IgG4 were not high in Ecuador, but were greater than in children from the United States. CONCLUSIONS: These results suggest that in areas of the developing world with endemic parasitism, α-Gal sensitization is (1) common, (2) associated with Ascaris exposure, and (3) distinguished by a low percentage of specific/total IgE compared with individuals with meat allergy in the United States.

Spring is associated with increased total and allergenic fungal concentrations in house dust from a pediatric asthma cohort in New York City.

Introduction: Asthma and allergy symptoms vary seasonally due to exposure to environmental sources of allergen, including fungi. However, we need an improved understanding of seasonal influence on fungal exposures in the indoor environment. We hypothesized that concentrations of total fungi and allergenic species in vacuumed dust vary significantly by season. Objective: Assess seasonal variation of indoor fungi with greater implications related to seasonal asthma control. Methods: We combined next-generation sequencing with quantitative polymerase chain reaction (qPCR) to measure concentrations of fungal DNA in indoor floor dust samples (n = 298) collected from homes participating in the New York City Neighborhood Asthma and Allergy Study (NAAS). Results: Total fungal concentration in spring was significantly higher than the other three seasons (p ≤ 0.005). Mean concentrations for 78% of fungal species were elevated in the spring (26% were significantly highest in spring, p < 0.05). Concentrations of 8 allergenic fungal species were significantly (p < 0.5) higher in spring compared to at least two other seasons. Indoor relative humidity and temperature were significantly highest in spring (p < 0.05) and were associated with total fungal concentration (R2 = 0.049, R2 = 0.11, respectively). Conclusion: There is significant seasonal variation in total fungal concentration and concentration of select allergenic species. Indoor relative humidity and temperature may underlie these associations.

Report of prenatal maternal demoralization and material hardship and infant rhinorrhea and watery eyes.

BACKGROUND: Previously, we found that reported infant rhinorrhea and watery eyes without a cold (RWWC) predicted school age exercise-induced wheezing, emergency department visits, and respiratory-related hospitalizations for asthma. These findings appeared independent of infant wheezing and allergy. Overall, we theorize that prenatal material hardship and psychosocial distress can induce infant dysregulation in the autonomic nervous system leading to infant RWWC and school age exercise-induced wheezing. OBJECTIVE: To test the hypotheses that indicators of prenatal stress and measures of maternal demoralization, which can alter infant autonomic nervous system responses, would predict infant RWWC. METHODS: In a prospective birth cohort of urban children (n = 578), pregnant women were queried in the third trimester about material hardship and maternal demoralization using validated instruments. Child RWWC was queried every 3 months in infancy. RESULTS: Notably, 44% of the mothers reported not being able to afford at least one of the basic needs of daily living during pregnancy, and children of those mothers were more likely to have infant RWWC (P < .001). The children had an increased risk of RWWC with increasing maternal demoralization during pregnancy (P < .001). In models controlling for sex, race and ethnicity, maternal asthma, maternal allergy, smoker in the home (pre- or postnatal), prenatal pesticide exposure, and older siblings, RWWC was predicted by mother's report of material hardship (relative risk, 1.22; P = .021) and maternal demoralization (relative risk, 1.14; P = .030). CONCLUSION: These results suggest an association between material hardship and psychological distress during pregnancy and RWWC in infancy, further supporting a link between infant autonomic dysregulation and RWWC.

Morphology and quantification of fungal growth in residential dust and carpets.

Mold growth indoors is associated with negative human health effects, and this growth is limited by moisture availability. Dust deposited in carpet is an important source of human exposure due to potential elevated resuspension compared to hard floors. However, we need an improved understanding of fungal growth in dust and carpet to better estimate human exposure. The goal of this study was to compare fungal growth quantity and morphology in residential carpet under different environmental conditions, including equilibrium relative humidity (ERH) (50%, 85%, 90%, 95%, 100%), carpet fiber material (nylon, olefin, wool) and presence/absence of dust. We analyzed incubated carpet and dust samples from three Ohio homes for total fungal DNA, fungal allergen Alt a 1, and fungal morphology. Dust presence and elevated ERH (≥85%) were the most important variables that increased fungal growth. Elevated ERH increased mean fungal DNA concentration (P < 0.0001), for instance by approximately 1000 times at 100% compared to 50% ERH after two weeks. Microscopy also revealed more fungal growth at higher ERH. Fungal concentrations were up to 100 times higher in samples containing house dust compared to no dust. For fiber type, olefin had the least total fungal growth, and nylon had the most total fungi and A. alternata growth in unaltered dust. Increased ERH conditions were associated with increased Alt a 1 allergen concentration. The results of this study demonstrate that ERH, presence/absence of house dust, and carpet fiber type influence fungal growth and allergen production in residential carpet, which has implications for human exposure.

Rice Consumption and Subclinical Lung Disease in US Adults: Observational Evidence From the Multi-Ethnic Study of Atherosclerosis.

Rice accumulates arsenic, an established lung toxicant. Little is known about the association of rice consumption with arsenic-related health effects, particularly interstitial lung disease. Between 2000 and 2002, 6,814 white, black, Hispanic, and Chinese adults from 6 US cities were enrolled in the Multi-Ethnic Study of Atherosclerosis. We included 2,250 participants who had spirometry data, 2,557 with full-lung computed tomography (CT) scans, and 5,710 with cardiac CT scans. Rice consumption and 310 participants with urinary arsenic were assessed at baseline. Spirometry and full-lung CT-derived measures of total lung capacity and high attenuation area (HAA), and interstitial lung abnormalities were measured at examination 5. Cardiac CT-derived HAA was measured at 1-3 visits. Twelve percent of participants reported eating at least 1 serving of rice daily. Comparing data between that group with those who ate less than 1 serving weekly, the mean difference for forced vital capacity was -102 (95% confidence interval (CI): -198, -7) mL, and for forced expiratory volume in 1 second was -90 (95% CI: -170, -11) mL after adjustment for demographics, anthropometrics, dietary factors, and smoking. The cross-sectional adjusted percent difference for total lung capacity was -1.33% (95% CI: -4.29, 1.72) and for cardiac-based HAA was 3.66% (95% CI: 1.22, 6.15). Sensitivity analyses for urinary arsenic were consistent with rice findings. Daily rice consumption was associated with reduced lung function and greater cardiac-based HAA.

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. METHODS: Through zip code, home addresses were linked to New York City Community Air Survey's land use regression model for street-level, annual average nitrogen dioxide (NO2), particulate matter (PM2.5), elemental carbon (EC), summer average ozone (O3), winter average sulfur dioxide (SO2) concentrations. Poisson regression models were fit to estimate the association (prevalence ratio, PR) between pollutant exposures and seeking urgent asthma care. RESULTS: All pollutants, except O3 were higher in HAPN than LAPN (P < 0.01). Neighborhood asthma prevalence modified the relationship between pollutants and urgent asthma (P-interaction < 0.01, for NO2 and SO3). Associations between pollutants and urgent asthma were observed only in LAPN (NO2: PR = 1.38, P = 0.01; SO3: PR = 1.85, P = 0.04). No association was observed between pollutants and urgent asthma among children in HAPN (P > 0.05). CONCLUSIONS: Relationships between modeled street-level pollutants and urgent asthma were stronger in LAPN compared to HAPN. Social stressors that may be more prevalent in HAPN than LAPN, could play a greater role in asthma exacerbations in HAPN vs. pollutant exposure alone.

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. OBJECTIVE: To test the hypothesis that rhinitis or watery eyes without cold symptoms (RWWC) in infancy predict development of EIW and urgent respiratory-related medical visits at school age, independent of seroatopy. METHODS: Within a prospective birth cohort of low-income, urban children (n = 332), RWWC was queried during the first year of life. Relative risks (RRs) for EIW, emergency department (ED) visits, and hospitalizations for asthma and other breathing difficulties at 5 to 7 years of age were estimated with multivariable models. Seroatopy was determined at 7 years of age. RESULTS: Infant RWWC was common (49% of children) and predicted school-age EIW (RR, 2.8; P < .001), ED visits (RR, 1.8; P = .001), and hospitalizations (RR, 9.8; P = .002). These associations were independent of infant wheeze. They were also independent of birth order, an indicator of increased risk of exposure to viruses in infancy, and infant ear infections, an indicator of sequelae of upper airway infections. The association between infant RWWC and ED visits at 5 to 7 years of age was attenuated (RR, 1.2; P = .23) when EIW at 5 to 7 years of age was included in the model, suggesting EIW mediates the association. Adjustment for seroatopy did not diminish the magnitudes of any of these associations. CONCLUSION: These findings suggest a nonallergic connection between infant nonwheeze symptoms and important consequences of urban respiratory health by school age through EIW.

Complex relationships between vitamin D and allergic sensitization among Puerto Rican 2-year-old children.

BACKGROUND: In the United States, Puerto Ricans have a higher prevalence of asthma than other Latino ethnicities. Low vitamin D levels for children living in northern climates could be a factor. OBJECTIVE: To assess serum 25-hydroxyvitamin D [25(OH)D] distributions (a marker of vitamin D) and associations among vitamin D, allergic sensitization, early wheeze, and home/demographic factors. METHODS: Puerto Rican infants born in New York City, with a maternal history of atopy, were enrolled in a birth cohort. Blood was collected at age 2 years (n = 154; 82 males and 72 females). Serum 25(OH)D and immunoglobulin E (IgE) (indoor allergen-specific and total) were determined using immunoassays. Home/demographic characteristics and respiratory symptoms were assessed by questionnaire. RESULTS: The median concentration of 25(OH)D was 22.6 ng/mL; 32% were at risk of deficiency or inadequacy (<12 or 12-19 ng/mL). Serum 25(OH)D levels were lower in the heating (a surrogate for less sun exposure in colder months) compared with nonheating (26.1 vs 22.7 ng/mL, P = .02) season, but were not associated with allergen-specific IgE levels or with level of acculturation (measured by maternal birthplace). However, low 25(OH)D levels (below median) were associated with high total IgE >100 IU/mL (P = .01). Also, 25(OH)D concentrations differed between children who attended daycare and those who did not (21.8 vs 24.5 ng/mL; t test, P = .02). Serum 25(OH)D was not associated with wheeze or asthma by 2 years of age (P = .43). CONCLUSION: Vitamin D deficiency, possibly linked with allergic pathways, may partially explain the trajectory for disproportionate asthma burden among Puerto Ricans, especially those born and raised in colder climates.

Assessment of exposure to air pollution in children: Determining whether wearing a personal monitor affects physical activity.

Personal air pollution monitoring in research studies should not interfere with usual patterns of behavior and bias results. In an urban pediatric cohort study we tested whether wearing an air monitor impacted activity time based on continuous watch-based accelerometry. The majority (71%) reported that activity while wearing the monitor mimicked normal activity. Correspondingly, variation in activity while wearing versus not wearing the monitor did not differ greatly from baseline variation in activity (P = 0.84).

NIAID, NIEHS, NHLBI, and MCAN Workshop Report: The indoor environment and childhood asthma-implications for home environmental intervention in asthma prevention and management.

Environmental exposures have been recognized as critical in the initiation and exacerbation of asthma, one of the most common chronic childhood diseases. The National Institute of Allergy and Infectious Diseases; National Institute of Environmental Health Sciences; National Heart, Lung, and Blood Institute; and Merck Childhood Asthma Network sponsored a joint workshop to discuss the current state of science with respect to the indoor environment and its effects on the development and morbidity of childhood asthma. The workshop included US and international experts with backgrounds in allergy/allergens, immunology, asthma, environmental health, environmental exposures and pollutants, epidemiology, public health, and bioinformatics. Workshop participants provided new insights into the biologic properties of indoor exposures, indoor exposure assessment, and exposure reduction techniques. This informed a primary focus of the workshop: to critically review trials and research relevant to the prevention or control of asthma through environmental intervention. The participants identified important limitations and gaps in scientific methodologies and knowledge and proposed and prioritized areas for future research. The group reviewed socioeconomic and structural challenges to changing environmental exposure and offered recommendations for creative study design to overcome these challenges in trials to improve asthma management. The recommendations of this workshop can serve as guidance for future research in the study of the indoor environment and on environmental interventions as they pertain to the prevention and management of asthma and airway allergies.

Relevance of specific IgE antibody titer to the prevalence, severity, and persistence of asthma among 19-year-olds in northern Sweden.

BACKGROUND: Although sensitization to indoor allergens is strongly associated with asthma, there are questions as to how this relates to asthma symptoms. OBJECTIVE: We sought to study the relevance of IgE antibodies to cat and dog allergens in an area in which (1) the climate discourages cockroach, fungal, and mite growth and (2) dander allergens are known to be present in schools and houses without animals. METHODS: IgE to 8 allergens was tested in 963 sera from a population-based study on 19-year-olds, and associations with asthma symptoms, diagnosis, and treatment were examined. In positive sera IgE to specific cat and dog allergens was also assayed. RESULTS: IgE specific for animal dander had the highest prevalence and strongest relationship to asthma diagnosis. Furthermore, asthma severity, as judged by the frequency of symptoms and use of treatment, was directly associated with the titer of IgE antibodies to animal dander. Among the 103 subjects who had current asthma at age 19 years, 50 had asthma before age 12 years. Among those 50, the odds ratios for asthma related to any IgE antibodies to animal dander or high-titer IgE antibodies (≥17.5 IU/mL) were 9.2 (95% CI, 4.9-17) and 13 (95% CI, 6.9-25), respectively. In multivariable analysis IgE antibodies to Fel d 1 and Can f 5 were each associated with current asthma. CONCLUSION: High-titer IgE antibodies to cat and dog allergens were strongly associated with the diagnosis, severity, and persistence of asthma; however, a large proportion of patients with current asthma did not live in a house with a cat or dog.

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. IgE against a panel of 112 antigens was measured using the ISAC multiplex panel array. Latent class analysis (LCA) was used to identify patterns of allergic sensitization among the 26 most common allergens against which children had measurable IgE. The association between patterns of allergic sensitization and risk of asthma and other allergic diseases was examined. RESULTS: LCA identified 4 patterns of allergic sensitization as follows: low risk of sensitization (prevalence of 53% in children with asthma and 76% in children without asthma), indoor (prevalence of 23% in children with asthma and 15% in children without asthma), pollen and indoor group 1 (prevalence of 16% in children with asthma and 5% in children without asthma), and pollen and indoor group 2 (prevalence of 9% in children with asthma and 4% in children without asthma). Compared with the low risk of sensitization pattern, children belonging to the 3 sensitized patterns had significantly higher risk of asthma at ages 7 to 8 years and 3 years later, with the highest risk for children in the pollen and indoor group 1 pattern. CONCLUSIONS: LCA facilitates the study of sensitization profiles to a large number of common allergens. Analyzing patterns of allergic sensitization from multiple allergens reveals additional relevant associations with asthma than the study of a single allergen or total IgE.

Atopy, but not obesity is associated with asthma severity among children with persistent asthma.

BACKGROUND AND OBJECTIVE: Obesity is associated with an increased risk of asthma in children. Atopic sensitization is a major risk factor for asthma including severe asthma in children. It is unclear if obesity is associated with worse asthma control or severity in children and how its effects compare to atopy. We sought to examine relationships of weight status and atopy to asthma control and severity among a population of predominantly low income, minority children and adolescents with persistent asthma. METHODS: A cross-sectional analysis of 832 children and adolescents, age range 5-17 years, with persistent asthma was performed. Clinical assessments included asthma questionnaires of symptoms, asthma severity score, health care utilization and medication treatment step, lung function testing, and skin prick testing as well as measures of adiposity. Data were collected between December 2010 and August 2014 from Johns Hopkins Hospital in Baltimore, MD and Children's Hospital of Boston, MA. RESULTS: Obesity was not associated with worse asthma control or severity in this group of predominantly low income, minority children and adolescents with persistent asthma. However, a greater degree of atopy was associated with lower lung function, higher asthma severity score, and higher medication treatment step. CONCLUSION: Atopy may be a more important risk factor for asthma severity than obesity among low-income minority children and adolescents with persistent asthma living in Northeastern cities in the United States.

Physical activity, black carbon exposure and airway inflammation in an urban adolescent cohort.

OBJECTIVE: Regular physical activity can improve cardiopulmonary health; however, increased respiratory rates and tidal volumes during activity may increase the effective internal dose of air pollution exposure. Our objective was to investigate the impact of black carbon (BC) measured by personal sampler on the relationship between physical activity and fractional exhaled nitric oxide (FeNO), a marker of airway inflammation. We hypothesized that higher personal BC would attenuate the protective effect of physical activity on airway inflammation. METHODS: We performed a cross-sectional study nested in a birth cohort of African American and Dominican children living in the Bronx and Northern Manhattan, New York City. Children were recruited based on age (target 9-14 year olds) and presence (n=70) or absence (n=59) of current asthma. Children wore wrist mounted accelerometers for 6 days and were classified as 'active' if they had ≥60min of moderate-to-vigorous activity (MVA) each day and 'non-active' if they had <60min of MVA on any given day, based on CDC guidelines. Personal BC measured using a MicroAeth, was assessed during two 24-h periods, at the beginning and end of physical activity assessment. High BC was defined as the upper tertile of BC measured with personal sampler. FeNO measurements were sampled at the beginning and end of the of physical activity assessment. RESULTS: In multivariable linear regression models, 'active' children had 25% higher personal BC concentrations (p=0.02) and 20% lower FeNO (p=0.04) compared to 'non-active' children. Among children with high personal BC (n=33), there was no relationship between activity and FeNO (p=1.00). The significant protective relationship between activity and airway inflammation was largely driven by children with lower personal BC (n=96, p=0.04). CONCLUSIONS: Children that live in an urban environment and are physically active on a daily basis have higher personal exposure to BC. High BC offsets the protective relationship between physical activity and airway inflammation.

Mold populations and dust mite allergen concentrations in house dust samples from across Puerto Rico.

Lifetime childhood asthma prevalence (LCAP) percentages in Puerto Rico Health Regions (HR) are substantially higher in northeastern vs. southwestern HR. Higher average relative humidity in the northeast might promote mold and mite exposures and possibly asthma prevalence. To test this hypothesis, mold contamination, Environmental Relative Moldiness Index (ERMI) values were measured in floor dust (n = 26) and dust mite allergen concentrations in bed dust (n = 14). For this analysis, the eight HR were divided into those with LCAP > 30% (n = 3) and < 30% (n = 5). The average ERMI value was significantly greater (Wilcoxon Rank Sum, p < 0.001) in high than in low LCAP HR (14.5 vs. 9.3). The dust mite antigens Der p 1, Der f 1, and Blo t 5 were detected in 90% of bed samples, but the concentrations were not significantly different in high vs. low LCAP HR. Mold exposures might partially explain the differences in LCAP HR in Puerto Rico.

Exhaled Nitric Oxide and Airway Hyperresponsiveness to Adenosine 5'-monophosphate and Methacholine in Children with Asthma.

BACKGROUND: There is increasing interest in the role of indirect bronchial challenges because clinical studies have shown that indirect airway hyperresponsiveness (AHR) reflects underlying airway inflammation better than direct AHR. Fractional exhaled nitric oxide (FeNO) appears to be a useful clinical tool for assessing airway inflammation noninvasively. We examined whether FeNO is more closely related to AHR to indirect stimuli than AHR to direct stimuli in children with mild to moderate asthma. METHODS: Fifty-nine asthmatic children aged 6-16 years without rhinitis, underwent spirometry, FeNO measurement and blood tests for serum total IgE, blood eosinophil count and serum eosinophil cationic protein (ECP). All subjects underwent methacholine and adenosine 5-monophosphate (AMP) challenge tests at intervals of 3 days. RESULTS: In a univariate linear regression analysis, FeNO was significantly associated with both PC20 AMP (R(2) = 0.341, p < 0.001) and PC20 methacholine (R(2) = 0.188, p = 0.001). After adjustment for age, sex, serum total IgE and blood eosinophil count, the association between FeNO and PC20 AMP (ß = -1.98, p = 0.001) was more robust than that between FeNO and PC20 methacholine (ß = -0.87, p = 0.081). The significant correlation between FeNO and PC20 AMP was observed in the steroid-naïve group (ß = -2.48, p = 0.001), but not in the steroid-treated group (ß = 0.88, p = 0.463). CONCLUSIONS: FeNO levels were more closely associated with PC20 AMP than with PC20 methacholine. This relationship could only be seen in the steroid-naïve subjects. These results suggest that FeNO levels in children with asthma may be more closely related to indirect AHR than to direct AHR.