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Background: Settled dust has been used in studies to assess exposures to allergens and other biologically active components, but it has not been considered in the aggregate in relation to respiratory health outcomes in the general population.Objective: We addressed whether total house dust weight, an index of total dust exposure, was associated with respiratory health outcomes in the National Survey of Lead and Allergens in Housing (1998-1999) (NSLAH).Methods: NSLAH was a cross-sectional survey designed to represent permanently occupied housing units in the United States. In each household, a questionnaire was administered and settled dust was vacuumed from five locations. Linear regression models were used to identify predictors of dust weight; logistic regression models were used to examine the relationship between dust weight and asthma and wheeze.Results: Dust weight samples were available for 829 households, and survey information was available for 2,456 participants (children and adults). Lower income, older homes, household pets, having a smoker in the house, and less frequent cleaning predicted higher dust weight levels in U.S. households. Higher levels of dust weight were associated with greater odds of current asthma and wheeze. The strongest associations were seen for wheeze [adjusted odds ratio (OR) = 1.99; 95% confidence interval (CI), 1.21-3.28 for bedroom bed dust; OR = 2.81; 95% CI, 1.52-5.21 for upholstery dust). These associations persisted when adjusting for allergen and endotoxin exposures.Conclusions: Dust weight, an index of total dust exposure in the home, may contribute to respiratory outcomes independently of the exposure to specific components. [ABSTRACT FROM AUTHOR]

Background: Although research has shown that early life exposure to household endotoxin protects against development of allergies, studies are less clear on the relationship between household endotoxin exposure and prevalence of wheezing and asthma. We assayed 2,552 house dust samples in a representative nationwide sam- ple to explore relationships between endotoxin exposures and risk factors for asthma, asthma symptoms, and medication use.Methods: House dust was vacuum-sampled from five locations within homes and assayed for endotoxin. Health, demographic, and housing information was assessed through questionnaire and on-site evaluation of 2,456 residents of 831 homes selected to represent the demographics of the United States.Results: Endotoxin concentration (EU/mg) and load (EU/m(2)) were highly correlated (r = 0.73-0.79). Geometric mean endotoxin concentrations were as follows (in EU/mg): bedroom floors, 35.3 (5th-95th percentile, 5.0-260); bedding, 18.7 (2.0-142); family room floors, 63.9 (11.5-331); sofas, 44.8 (6.4-240); and kitchen floors, 80.5 (9.8-512). Multivariate analysis demonstrated significant relationships between increasing endotoxin levels and diagnosed asthma, asthma symptoms in the past year, current use of asthma medications, and wheezing among residents of the homes. These relationships were strongest for bedroom floor and bedding dust and were observed in adults only. Modeling the joint effect of bedding and bedroom floor endotoxin on recent asthma symptoms yielded an adjusted odds ratio of 2.83 (95% confidence interval, 1.01-7.87). When stratified by allergy status, allergic subjects with higher endotoxin exposure were no more likely to have diagnosed asthma or asthma symptoms than nonallergic subjects.Conclusion: This study demonstrates that household endotoxin exposure is a significant risk factor for increased asthma prevalence. [ABSTRACT FROM AUTHOR]

Studies of indoor allergen exposures are often limited by the cost and logistics of sending technicians to homes to collect dust. In this study we evaluated the feasibility of having subjects collect their own dust samples. The objectives were to compare allergen concentrations between subject- and technician-collected samples and to examine the sample return rate. Using a dust collection device and written instructions provided to them by mail, 102 subjects collected a combined dust sample from a bed and bedroom floor. Later the same day, a technician collected a side-by-side sample. Dust samples were weighed and analyzed for the cat allergen Fel d 1 and the dust mite allergen Der p 1. Fifty additional subjects who were enrolled by telephone were mailed dust collection packages and asked to return a dust sample and questionnaire by mail. A technician did not visit their homes. Correlations between subject- and technician-collected samples were strong for concentrations of Fel d 1 (r = 0.88) and Der p 1 (r = 0.87). With allergen concentrations dichotomized at lower limits of detection and clinically relevant thresholds, agreements between methodologies ranged from 91 to 98%. Although dust weights were correlated (r = 0.48, p < 0.001), subjects collected lighter samples. Among the group of 50 subjects, 46 returned a dust sample and completed questionnaire. The median number of days to receive a sample was 15. With some limitations, subject-collected dust sampling appears to be a valid and practical option for epidemiologic and clinical studies that report allergen concentration as a measure of exposure. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Cigarette smoking is a leading risk factor for periodontal disease. This cross-sectional study investigated the relation between environmental tobacco smoke (ETS) and periodontal disease in the United States. METHODS: Data were obtained from the Third National Health and Nutrition Examination Survey (1988-1994). The outcome was periodontal disease, defined as 1 or more periodontal sites with attachment loss of 3 mm or greater and a pocket depth of 4 mm or greater at the same site. Exposure to ETS at home and work was self-reported. The study analyzed 6611 persons 18 years and older who had never smoked cigarettes or used other forms of tobacco. RESULTS: Exposure to ETS at home only, work only, and both was reported by 18.0%, 10.7%, and 3.8% of the study population, respectively. The adjusted odds of having periodontal disease were 1.6 (95% confidence interval = 1.1, 2.2) times greater for persons exposed to ETS than for persons not exposed. CONCLUSIONS: Among persons in the United States who had never used tobacco, those exposed to ETS were more likely to have periodontal disease than were those not exposed to ETS. © 2002 by the United States Cancer Pain Relief Committee. [ABSTRACT FROM AUTHOR]

Introduction: The migraine-preventive drug propranolol is efficacious in reducing pain from temporomandibular disorder, suggesting potential modifying or mediating effects of comorbid migraine., Methods: In this randomized controlled trial, myofascial temporomandibular disorder patients were treated with propranolol or placebo for 9 weeks. The primary endpoint was change in a facial pain index derived from daily symptom diaries. Linear and logistic regression models tested for a migraine × treatment-group interaction in reducing facial pain index. Counterfactual models explored changes in headache impact and heart rate as mediators of propranolol's efficacy., Results: Propranolol's efficacy in reducing facial pain index was greater among the 104 migraineurs than the 95 non-migraineurs: For example, for the binary ≥ 30% reduction in facial pain index, odds ratios were 3.3 (95% confidence limits: 1.4, 8.1) versus 1.3 (0.5, 3.2), respectively, although the interaction was statistically non-significant ( p  = 0.139). Cumulative response curves confirmed greater efficacy for migraineurs than non-migraineurs (differences in area under the curve 26% and 6%, respectively; p  = 0.081). While 9% of the treatment effect was mediated by reduced headache impact, 46% was mediated by reduced heart rate., Conclusions: Propranolol was more efficacious in reducing temporomandibular disorder pain among migraineurs than non-migraineurs, with more of the effect mediated by reduced heart rate than by reduced headache impact., Study Identification and Registration: SOPPRANO; NCT02437383; https://clinicaltrials.gov/ct2/show/NCT02437383.

Background: Headache attributed to Temporomandibular Disorder (HATMD) is a secondary headache that may have features resulting in diagnostic overlap with primary headaches, namely, tension-type (TTH) or migraine. This cross-sectional study of people with both chronic myogenous TMD and primary headaches evaluated characteristics associated with HATMD., Methods: From a clinical trial of adults, baseline data were used from a subset with diagnoses of both TMD myalgia according to the Diagnostic Criteria for TMD (DC/TMD) and TTH or migraine according to the International Classification of Headache Disorders, 3rd edition. HATMD was classified based on the DC/TMD. Questionnaires and examinations evaluated 42 characteristics of facial pain, headache, general health, psychological distress, and experimental pain sensitivity. Univariate regression models quantified the associations of each characteristic with HATMD (present versus absent), headache type (TTH versus migraine), and their interaction in a factorial design. Multivariable lasso regression identified the most important predictors of HATMD., Results: Of 185 participants, 114 (61.6%) had HATMD, while the numbers with TTH (n = 98, 53.0%) and migraine (n = 87, 47.0%) were similar. HATMD was more likely among migraineurs (61/87 = 70.1%) than participants with TTH (53/98 = 54.1%; odds ratio = 2.0; 95%CL = 1.1, 3.7). In univariate analyses, characteristics associated with HATMD included pain-free jaw opening and examination-evoked pain in masticatory muscles and temporomandibular joints (TMJ) as well as frequency and impact of headache, but not frequency or impact of facial pain. Lowered blood pressure but not psychological or sensory characteristics was associated with HATMD. Multiple characteristics of facial pain, headache, general health, and psychological distress differed between TTH or migraine groups. Few interactions were observed, demonstrating that most characteristics' associations with HATMD were consistent in TTH and migraine groups. The lasso model identified headache frequency and examination-evoked muscle pain as the most important predictors of HATMD., Conclusions: HATMD is highly prevalent among patients with chronic myogenous TMD and headaches and often presents as migraine. In contrast to primary headaches, HATMD is associated with higher headache frequency and examination-evoked masticatory muscle pain, but with surprisingly few measures of facial pain, general health, and psychological distress. A better understanding of HATMD is necessary for developing targeted strategies for its management., Trial Identification and Registration: SOPPRANO; NCT02437383 . Registered May 7, 2015.

Propranolol is a nonselective β-adrenergic receptor antagonist that is efficacious in reducing facial pain. There is evidence that its analgesic efficacy might be modified by variants of the catechol-O-methyltransferase ( COMT ) gene. We tested the hypothesis in a subset of 143 non-Hispanic Whites from a randomized controlled trial of patients with painful temporomandibular disorder (TMD). Patients were genotyped for rs4680, a single nucleotide polymorphism of COMT , and randomly allocated to either propranolol 60 mg twice daily or placebo. During the 9-wk follow-up period, patients recorded daily ratings of facial pain intensity and duration; the product was computed as an index of facial pain. Postbaseline change in the index at week 9 (the primary endpoint) was analyzed as a continuous variable and dichotomized at thresholds of ≥30% and ≥50% reduction. Mixed models for repeated measures tested for the genotype × treatment group interaction and estimated means, odds ratios (ORs), and 95% confidence limits (95% CLs) of efficacy within COMT genotypes assuming an additive genetic model. In secondary analysis, the cumulative response curves were plotted for dichotomized reductions ranging from ≥20% to ≥70%, and genotype differences in area under the curve percentages (%AUC) were calculated to signify efficacy. Mean index reduction did not differ significantly ( P = 0.277) according to genotype, whereas the dichotomized ≥30% reduction revealed greater efficacy among G:G homozygotes (OR = 10.9, 95%CL = 2.4, 50.7) than among A:A homozygotes (OR = 0.8, 95%CL = 0.2, 3.2) with statistically significant interaction ( P = 0.035). Cumulative response curves confirmed greater ( P = 0.003) efficacy for G:G homozygotes (%AUC difference = 43.7, 95%CL = 15.4, 72.1) than for A:A homozygotes (%AUC difference = 6.5, 95%CL = -30.2, 43.2). The observed antagonistic effect of the A allele on propranolol's efficacy was opposite the synergistic effect hypothesized a priori. This unexpected result highlights the need for better knowledge of COMT's role in pain pathogenesis if the gene is to be used for precision-medicine treatment of TMD (ClinicalTrials.gov NCT02437383).

Background: In 2017, the Addendum Guidelines for the Prevention of Peanut Allergy were published with recommendations on early introduction of peanut-containing foods based on infants' clinical history., Objective: We sought to conduct a nationwide US survey to assess Guidelines implementation among allergists and immunologists who manage infants for food allergy., Methods: Survey invitations were delivered to 3281 nonretired, US members of the American Academy of Asthma, Allergy & Immunology, board certified in allergy and immunology. The survey assessed awareness and implementation of the Guidelines and barriers to implementation. Descriptive statistics were generated., Results: Twenty-nine percent (946 of 3281) of surveyed allergists/immunologists responded, and 87.1% (825 of 946) of responders met eligibility criteria. Among eligible responders, 97.1% were aware of the Guidelines. Of these, 64.5% reported full implementation of the Guidelines as published, 34.4% reported partial implementation, and 1.1% reported using none of the Guidelines. Barriers to Guidelines use included parental (47.6%) and self (21.8%) concerns about allergic reactions, lack of referrals (33.6%), parents uninterested in early feeding (28.2%), and lack of clinic time (20.9%). The 2 most common deviations from the Guidelines were considering additional factors not specified in the Guidelines such as family history (50.2%) and conducting skin prick testing in non-high-risk children (43.9%). Of respondents using the Guidelines, 45.7% indicated they needed more education or training., Conclusions: Essentially all allergists/immunologists who responded to the survey reported full or partial Guidelines implementation. Parental concerns and lack of referrals are major identifiable barriers. Improved Guidelines messaging to parents and referring physicians is warranted., (Copyright © 2020 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Propranolol is a nonselective beta-adrenergic receptor antagonist. A multicenter, randomized, double-blind, placebo-controlled, parallel-group, phase 2b trial enrolled participants aged 18 to 65 years with temporomandibular disorder myalgia to evaluate efficacy and safety of propranolol compared with placebo in reducing facial pain. Participants were randomized 1:1 to either extended-release propranolol hydrochloride (60 mg, BID) or placebo. The primary endpoint was change in facial pain index (FPI = facial pain intensity multiplied by facial pain duration, divided by 100). Efficacy was analyzed as a mean change in FPI from randomization to week 9 and as the proportion of participants with ≥30% or ≥50% reductions in FPI at week 9. Regression models tested for treatment-group differences adjusting for study site, sex, race, and FPI at randomization. Of 299 participants screened, 200 were randomized; 199 had at least one postrandomization FPI measurement and were included in intention-to-treat analysis. At week 9, model-adjusted reductions in mean FPI did not differ significantly between treatment groups (-1.8, 95% CL: -6.2, 2.6; P = 0.41). However, the proportion with a ≥30% reduction in FPI was significantly greater for propranolol (69.0%) than placebo (52.6%), and the associated number-needed-to-treat was 6.1 (P = 0.03). Propranolol was likewise efficacious for a ≥50% reduction in FPI (number-needed-to-treat = 6.1, P = 0.03). Adverse event rates were similar between treatment groups, except for more frequent fatigue, dizziness, and sleep disorder in the propranolol group. Propranolol was not different from placebo in reducing mean FPI but was efficacious in achieving ≥30% and ≥50% FPI reductions after 9 weeks of treatment among temporomandibular disorder participants.

Importance: The 2017 Addendum Guidelines for the Prevention of Peanut Allergy in the United States recommend that pediatricians assess infant peanut allergy risk and introduce peanut in the diet at age 4 to 6 months. Early introduction has the potential to prevent peanut allergy development., Objectives: To measure the rates of guideline awareness and implementation and to identify barriers to and factors associated with implementation among US pediatricians., Design, Setting, and Participants: This population-based study survey used a 29-item electronic survey instrument that was administered to pediatricians practicing across the United States from June 1, 2018, to December 1, 2018. Invitations to complete a survey were emailed to all pediatricians in the American Academy of Pediatrics vendor database. Eligible participants were nonretired US-based pediatricians providing general care to infants aged 12 months or younger., Main Outcomes and Measures: The primary outcome was the prevalence of guideline implementation, which was measured by 1 survey item about awareness followed by a second item about implementation. Secondary outcomes included identification of guidelines-focused services provided by pediatricians, knowledge of the guidelines (measured with 3 clinical scenarios), barriers to guideline implementation, need for training, and facilitators of guideline implementation., Results: A total of 1781 pediatricians were eligible to participate and completed the entire survey. Most respondents self-identified as white (1287 [72.5%]) and female (1210 [67.4%]) individuals. Overall, 1725 (93.4%; 95% CI, 92.2%-94.5%) pediatricians reported being aware of the guidelines. Of those pediatricians who had knowledge of the guidelines, 497 (28.9%; 95% CI, 26.8%-31.1%) reported full implementation and 1105 (64.3%; 95% CI, 62.0%-66.6%) reported partial implementation. Common barriers to implementation included parental concerns about allergic reactions (reported by 575 respondents [36.6%; 95% CI, 34.3%-39.1%]), uncertainty in understanding and correctly applying the guidelines (reported by 521 respondents [33.2%; 95% CI, 30.9%-35.6%]), and conducting in-office supervised feedings (reported by 509 respondents [32.4%; 95% CI, 30.1%-34.8%]). Many pediatricians (1175 [68.4%; 95% CI, 66.1%-70.5%]) reported a need for further training on the guidelines., Conclusions and Relevance: This survey found that most pediatrician respondents appeared to know of the 2017 guidelines, but less than one-third of respondents reported full implementation. Results of this study may inform future efforts to eliminate barriers to guideline implementation and adherence, thereby reducing the incidence of peanut allergy in infants.

Background: Short-term targeted treatment can potentially prevent fall asthma exacerbations while limiting therapy exposure., Objective: We sought to compare (1) omalizumab with placebo and (2) omalizumab with an inhaled corticosteroid (ICS) boost with regard to fall exacerbation rates when initiated 4 to 6 weeks before return to school., Methods: A 3-arm, randomized, double-blind, double placebo-controlled, multicenter clinical trial was conducted among inner-city asthmatic children aged 6 to 17 years with 1 or more recent exacerbations (clincaltrials.gov #NCT01430403). Guidelines-based therapy was continued over a 4- to 9-month run-in phase and a 4-month intervention phase. In a subset the effects of omalizumab on IFN-α responses to rhinovirus in PBMCs were examined., Results: Before the falls of 2012 and 2013, 727 children were enrolled, 513 were randomized, and 478 were analyzed. The fall exacerbation rate was significantly lower in the omalizumab versus placebo arms (11.3% vs 21.0%; odds ratio [OR], 0.48; 95% CI, 0.25-0.92), but there was no significant difference between omalizumab and ICS boost (8.4% vs 11.1%; OR, 0.73; 95% CI, 0.33-1.64). In a prespecified subgroup analysis, among participants with an exacerbation during the run-in phase, omalizumab was significantly more efficacious than both placebo (6.4% vs 36.3%; OR, 0.12; 95% CI, 0.02-0.64) and ICS boost (2.0% vs 27.8%; OR, 0.05; 95% CI, 0.002-0.98). Omalizumab improved IFN-α responses to rhinovirus, and within the omalizumab group, greater IFN-α increases were associated with fewer exacerbations (OR, 0.14; 95% CI, 0.01-0.88). Adverse events were rare and similar among arms., Conclusions: Adding omalizumab before return to school to ongoing guidelines-based care among inner-city youth reduces fall asthma exacerbations, particularly among those with a recent exacerbation., (Copyright © 2015 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Background: Allergic sensitization is an important risk factor for the development of atopic disease. The National Health and Nutrition Examination Survey (NHANES) 2005-2006 provides the most comprehensive information on IgE-mediated sensitization in the general US population., Objective: We investigated clustering, sociodemographic, and regional patterns of allergic sensitization and examined risk factors associated with IgE-mediated sensitization., Methods: Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Participants aged 1 year or older (n = 9440) were tested for serum specific IgEs (sIgEs) to inhalant and food allergens; participants 6 years or older were tested for 19 sIgEs, and children aged 1 to 5 years were tested for 9 sIgEs. Serum samples were analyzed by using the ImmunoCAP System. Information on demographics and participants' characteristics was collected by means of questionnaire., Results: Of the study population aged 6 years and older, 44.6% had detectable sIgEs, whereas 36.2% of children aged 1 to 5 years were sensitized to 1 or more allergens. Allergen-specific IgEs clustered into 7 groups that might have largely reflected biological cross-reactivity. Although sensitization to individual allergens and allergen types showed regional variation, the overall prevalence of sensitization did not differ across census regions, except in early childhood. In multivariate modeling young age, male sex, non-Hispanic black race/ethnicity, geographic location (census region), and reported pet avoidance measures were most consistently associated with IgE-mediated sensitization., Conclusions: The overall prevalence of allergic sensitization does not vary across US census regions, except in early life, although allergen-specific sensitization differs based on sociodemographic and regional factors. Biological cross-reactivity might be an important but not the sole contributor to the clustering of allergen-specific IgEs., (Published by Mosby, Inc.)

Background: Atopy is an established risk factor for asthma, and an elevated eosinophil level is a hallmark of atopic and non-atopic asthma. Whether atopy and eosinophils act independently or interact to influence asthma has clinical and public health implications., Objective: To investigate the relationship between atopy and eosinophils in asthma., Methods: Data on current asthma, atopy (IgE positive to ≥ 1 allergen), and blood eosinophil percent (dichotomized at the median) were obtained for persons aged ≥ 6 years from the National Health and Nutrition Examination Survey 2005-2006. Interaction on an additive scale was evaluated by estimating the prevalences of asthma for combinations of atopy (yes or no) and eosinophil percent (high or low) and calculating the excess prevalence due to interaction., Results: For all ages combined, the adjusted prevalences of asthma were 4.6%, 7.6%, 6.9% and 17.2% for persons with neither factor, atopy alone, a high eosinophil percent alone and both factors respectively. The excess prevalence of asthma due to interaction was 7.2%, indicating synergism. The excess prevalence was greatest in children aged 6-17 years (15.3%), and it decreased with each older age category until it was absent in adults aged ≥ 55 years (-0.2%). In children, 94% of asthma cases attributable to the 2 factors were attributable to the interaction, whereas in the oldest adults, no cases were attributable to the interaction., Conclusions and Clinical Relevance: Interaction between atopy and an elevated eosinophil level in asthma cases was very strong in children but absent in the oldest adults, which suggests different mechanistic pathways for these factors by age and supports the notion that asthma is a heterogeneous disease. In addition, the age-dependent interaction between the factors has potential implications for the selection of asthma patients for treatments that would target either IgE or a high eosinophil level., (Published 2012. This article is a US Government work and is in the public domain in the USA.)

Background: Consistent performance of allergen assays is essential to ensure reproducibility of exposure assessments for investigations of asthma and occupational allergic disease. This study evaluated intra- and inter-laboratory reproducibility of a fluorescent multiplex array, which simultaneously measures eight indoor allergens in a single reaction well., Methods: A multi-center study was performed in nine laboratories in the US and Europe to determine the inter-laboratory variability of an 8-plex array for dust mite, cat, dog, rat, mouse and cockroach allergens. Aliquots of 151 dust extract samples were sent to participating centers and analyzed by each laboratory on three separate occasions. Agreement within and between laboratories was calculated by the concordance correlation coefficient (CCC)., Results: Results were obtained for over 32,000 individual allergen measurements. Levels covered a wide range for all allergens from below the lower limit of detection (LLOD = 0.1-9.8 ng/ml) to higher than 6800 ng/ml for all allergens except Mus m 1, which was up to 1700 ng/ml. Results were reproducible within as well as between laboratories. Within laboratories, 94% of CCC were ≥ 0.90, and 80% of intra-laboratory results fell within a 10% coefficient of variance (CV%). Results between laboratories also showed highly significant positive correlations for all allergens (~0.95, p<0.001). Overall means of results were comparable, and inter-laboratory CV% for all allergens except Rat n 1 ranged between 17.6% and 26.6%., Conclusion: The data indicate that performance criteria for fluorescent multiplex array technology are reproducible within and between laboratories. Multiplex technology provides standardized and consistent allergen measurements that will streamline environmental exposure assessments in allergic disease., (Copyright © 2012. Published by Elsevier B.V.)

The hygiene hypothesis contends that fewer opportunities for infections and microbial exposures have resulted in more widespread asthma and atopic disease. Consistent with that hypothesis, decreases in infectious oral diseases over the past half century have coincided with increases in the prevalence of asthma and other allergic diseases. This observation has led some researchers to speculate that exposures to oral bacteria, including pathogens associated with periodontal diseases, such as gingivitis and periodontitis, might play a protective role in the development of asthma and allergy. Colonization of the oral cavity with bacteria, including some species of periodontal pathogens, begins shortly after birth, and the detection of serum antibodies to oral pathogens in early childhood provides evidence of an early immune response to these bacteria. Current knowledge of the immune response to oral bacteria and the immunologic pathogenesis of periodontal diseases suggests biologically plausible mechanisms by which oral pathogens could influence the risk of allergic disease. However, studies investigating the association between oral pathogen exposures and allergic disease are few in number and limited by cross-sectional or case-control design, exclusion of young children, and use of surrogate measures of oral bacterial colonization. Additional studies, particularly well-designed case-control studies among very young children and prospective birth cohort studies, are needed., (Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: The National Health and Nutrition Examination Survey (NHANES) 2005-2006 was the first population-based study to investigate levels of serum total and allergen-specific IgE in the general US population., Objective: We estimated the prevalence of allergy-related outcomes and examined relationships between serum IgE levels and these outcomes in a representative sample of the US population., Methods: Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Study subjects aged 6 years and older (n = 8086) had blood taken for measurement of total IgE and 19 specific IgE levels against common aeroallergens, including Alternaria alternata, Aspergillus fumigatus, Bermuda grass, birch, oak, ragweed, Russian thistle, rye grass, cat dander, cockroach, dog dander, dust mite (Dermatophagoides farinae and Dermatophagoides pteronyssinus), mouse and rat urine proteins, and selected foods (egg white, cow's milk, peanut, and shrimp). Serum samples were analyzed for total and allergen-specific IgE by using the Pharmacia CAP System. Information on allergy-related outcomes and demographics was collected by questionnaire., Results: In NHANES 2005-2006, 6.6% reported current hay fever, and 23.5% had current allergies. Allergy-related outcomes increased with increasing total IgE levels (adjusted odds ratios for a 10-fold increase in total IgE level of 1.86 [95% CI, 1.44-2.41] for hay fever and 1.64 [95% CI, 1.41-1.91] for allergies). Increased levels of plant-, pet-, and mold-specific IgE contributed independently to allergy-related symptoms. The greatest increase in odds was observed for hay fever and plant-specific IgE (adjusted odds ratio, 4.75; 95% CI, 3.83-5.88)., Conclusion: In the US population self-reported allergy symptoms are most consistently associated with increased levels of plant-, pet-, and mold-specific IgE., (Published by Mosby, Inc.)

Accumulating evidence suggests that bacteria associated with periodontal disease may exert systemic immunomodulatory effects. Although the improvement in oral hygiene practices in recent decades correlates with the increased incidence of asthma in developed nations, it is not known whether diseases of the respiratory system might be influenced by the presence of oral pathogens. The present study sought to determine whether subcutaneous infection with the anaerobic oral pathogen Porphyromonas gingivalis exerts a regulatory effect on allergic airway inflammation. BALB/c mice sensitized and subsequently challenged with ovalbumin exhibited airway hyperresponsiveness to methacholine aerosol and increased airway inflammatory cell influx and Th2 cytokine (interleukin-4 [IL-4], IL-5, and IL-13) content relative to those in nonallergic controls. Airway inflammatory cell and cytokine contents were significantly reduced by establishment of a subcutaneous infection with P. gingivalis prior to allergen sensitization, whereas serum levels of ovalbumin-specific IgE and airway responsiveness were not altered. Conversely, subcutaneous infection initiated after allergen sensitization did not alter inflammatory end points but did reduce airway responsiveness in spite of increased serum IgE levels. These data provide the first direct evidence of a regulatory effect of an oral pathogen on allergic airway inflammation and responsiveness. Furthermore, a temporal importance of the establishment of infection relative to allergen sensitization is demonstrated for allergic outcomes.

Background: The inability to measure IgE-based sensitivity to all allergens has limited our understanding of what portion of asthma is related to IgE. Total IgE measurement can potentially overcome this limitation., Objective: We sought to determine the association between total IgE levels and asthma., Methods: The National Health and Nutrition Examination Survey 2005-2006 examined a representative sample of the US population 6 years of age and older., Results: The median total IgE level was 40.8 kU/L (interquartile range, 15.5-114 kU/L). Total IgE levels varied with age, sex, race/ethnicity, serum cotinine level, body size, and socioeconomic status. The prevalence of current asthma was 8.8%. The prevalence of atopy was 42.5%, as defined by 15 specific IgEs. The adjusted odds ratio (OR) for asthma with a 10-fold increase in total IgE level was 2.18 (95% CI, 1.66-2.87). Total IgE level predicted asthma only among atopic subjects (OR, 2.41; 95% CI, 1.62-3.60) and not among nonatopic subjects (OR, 1.11; 95% CI, 0.72-1.71; interaction P = .005). Among atopic subjects, the association between total IgE level and asthma became stronger as the number of positive specific IgE test results increased. Asthma was present at even the lowest levels of total IgE, regardless of atopic status. Approximately 92% of atopic subjects were identified by 6 specific IgEs, but to increase the identification to more than 99% required 11 specific IgEs., Conclusion: Total IgE levels are associated with asthma only among persons who have positive results for at least 1 allergen-specific IgE. Asthma independent of IgE is not uncommon in the US population. The complete identification of atopic subjects in a population requires a large panel of allergen-specific IgEs.

Background: The incidence and morbidity of wheezing illnesses and childhood asthma is especially high in poor urban areas. This paper describes the study design, methods, and population of the Urban Environment and Childhood Asthma (URECA) study, which was established to investigate the immunologic causes of asthma among inner-city children., Methods and Results: URECA is an observational prospective study that enrolled pregnant women in central urban areas of Baltimore, Boston, New York City, and St. Louis and is following their offspring from birth through age 7 years. The birth cohort consists of 560 inner-city children who have at least one parent with an allergic disease or asthma, and all families live in areas in which at least 20% of the population has incomes below the poverty line. In addition, 49 inner-city children with no parental history of allergies or asthma were enrolled. The primary hypothesis is that specific urban exposures in early life promote a unique pattern of immune development (impaired antiviral and increased Th2 responses) that increases the risk of recurrent wheezing and allergic sensitization in early childhood, and of asthma by age 7 years. To track immune development, cytokine responses of blood mononuclear cells stimulated ex vivo are measured at birth and then annually. Environmental assessments include allergen and endotoxin levels in house dust, pre- and postnatal maternal stress, and indoor air nicotine and nitrogen dioxide. Nasal mucous samples are collected from the children during respiratory illnesses and analyzed for respiratory viruses. The complex interactions between environmental exposures and immune development will be assessed with respect to recurrent wheeze at age 3 years and asthma at age 7 years., Conclusion: The overall goal of the URECA study is to develop a better understanding of how specific urban exposures affect immune development to promote wheezing illnesses and asthma.

Background: The National Survey of Lead and Allergens in Housing was the first population-based study to measure indoor allergen levels in US homes., Objective: We characterized the overall burden to multiple allergens and examined whether increased allergen levels were associated with occupants' asthma status., Methods: This cross-sectional study surveyed a nationally representative sample of 831 housing units in 75 different locations throughout the United States. Information was collected by means of questionnaire and environmental assessment. Allergen concentrations in dust samples were assessed by using immunoassays. The following cutoff points were used to define increased allergen levels: 10 microg/g for Der p 1, Der f 1, and Can f 1; 8 microg/g for Fel d 1; 8 U/g for Bla g 1; 1.6 microg/g for mouse urinary protein; and 7 microg/g for Alternaria alternata antigens. Allergen burden was considered high when 4 or more allergens exceeded increased levels in any of the sampling locations., Results: Exposure to multiple allergens was common in US homes. Of the surveyed homes, 51.5% had at least 6 detectable allergens and 45.8% had at least 3 allergens exceeding increased levels. Race, income, housing type, absence of children, and presence of smokers, pets, cockroaches, rodents, and mold/moisture-related problems were independent predictors of high allergen burden. Among atopic subjects, high allergen burden increased the odds of having asthma symptoms (odds ratio, 1.81; 95% CI, 1.04-3.15)., Conclusion: Increased allergen levels in the home are associated with asthma symptoms in allergic individuals.

Background: The percentage of asthma cases attributable to atopy is the subject of debate., Objectives: The objectives were to estimate the percentage of asthma cases in the US population attributable to atopy and to examine associations between allergen-specific skin tests and asthma., Methods: Data were obtained from the Third National Health and Nutrition Examination Survey, in which subjects age 6 to 59 years were skin tested with 10 allergens. Atopy was defined as at least 1 positive allergen-specific test. Doctor-diagnosed current asthma was assessed by questionnaire., Results: In the United States, 56.3% of the asthma cases were attributable to atopy, and that percentage was greater among males than females, among persons in the highest education category than in lower education categories, and among persons living in highly populated metropolitan areas than in all other areas. Each allergen-specific test was strongly associated with asthma before adjustment (odds ratios varied from 2.1 to 4.5); however, after adjustment by all the allergens, only tests to cat, Alternaria, white oak, and perennial rye were independently associated with asthma. Perennial rye was inversely associated with asthma. Of the 10 allergens, a positive response to cat accounted for the highest percentage of asthma cases (29.3%)., Conclusion: About half of the current asthma cases in the US population represented by the Third National Health and Nutrition Examination Survey were attributable to atopy. Some allergen-specific skin tests were not independently associated with asthma., Clinical Implications: If atopy could be prevented or reversed, or its effect on asthma blocked, then a large percentage of asthma cases in the US population could be prevented.

Accumulating evidence suggests that gender affects the incidence, susceptibility and severity of several lung diseases. Gender also influences lung development and physiology. Data from both human and animal studies indicate that sex hormones might contribute to disease pathogenesis or serve as protective factors, depending on the disease involved. In this review, the influence of gender and sex hormones on lung development and pathology will be discussed, with specific emphasis on pulmonary fibrosis, asthma and cancer.

Background: We previously reported significant reductions in cockroach allergen concentrations in urban homes by reducing cockroach infestations., Objective: To determine the effectiveness of pest control performed by professional entomologists, compared with commercial companies, in reducing cockroach allergen., Methods: This 3-arm randomized controlled trial enrolled 60 cockroach-infested homes in North Carolina. Homes were randomly assigned to a control group or 1 of 2 treatment groups. Treatment 1 had insecticide baits placed by entomologists from North Carolina State University. Treatment 2 received pest control from a randomly assigned commercial company. Vacuumed dust sampling and cockroach trapping were conducted at 0, 6, and 12 months. Dust samples were analyzed by ELISA., Results: In treatment 1 homes, there were significant reductions in geometric mean trap counts compared with control and treatment 2 homes at 12 months. Relative to control, significant 12-month reductions in Bla g 1 were evident in treatment 1 homes at all sampled sites, except bedroom floor. From baseline to month 12, geometric mean Bla g 1 concentrations (U/g) decreased from 64.2 to 5.6 in kitchen, 10.6 to 1.1 in living room, 10.7 to 1.9 on bedroom floor, and 3.6 to 2.3 in bed. Treatment 2 homes showed no significant 12-month allergen reductions versus control., Conclusion: Reductions in Bla g 1 in cockroach-infested homes can be achieved by reducing infestations; however, the magnitude of allergen reduction is dependent on the thoroughness and effectiveness of cockroach eradication efforts., Clinical Implications: Elimination of cockroaches is an effective method for reducing exposure to cockroach allergen.

Background: The hygiene hypothesis contends that fewer opportunities for infection have led to increases in the prevalences of asthma and other allergic diseases., Objective: This study evaluated the association between asthma, wheeze, and hay fever and antibodies to 2 oral bacteria associated with periodontal disease., Methods: Data were obtained from the Third National Health and Nutrition Examination Survey. Serum levels of IgG antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were quantified by enzyme-linked immunoassays in 9385 subjects age 12 years and older. The outcomes were current asthma, wheeze, and hay fever. Odds ratios (ORs) representing a 1-log-unit increase in IgG concentrations were estimated with logistic regression. ORs were adjusted for 8 confounders and weighted to represent the US population., Results: For each disease outcome, geometric mean antibody concentrations were higher in persons without the disease outcome than with the disease outcome. For a 1-log-unit increase in P gingivalis antibody concentration, adjusted ORs were 0.41 (95% CI, 0.20-0.87) for asthma, 0.43 (0.23-0.78) for wheeze, and 0.45 (0.23-0.93) for hay fever. For A actinomycetemcomitans, those ORs were 0.56 (0.19-1.72), 0.39 (0.17-0.86), and 0.48 (0.23-1.03), respectively., Conclusion: Consistent with the hygiene hypothesis, higher concentrations of IgG antibodies to P gingivalis were significantly associated with lower prevalences of asthma, wheeze, and hay fever, and higher concentrations of IgG antibodies to A actinomycetemcomitans were significantly associated with a lower prevalence of wheeze., Clinical Implications: Colonization of the oral cavity by bacteria and other microbes might play a protective role in the etiology of allergic disease.

Background: Exposure to the fungus Alternaria alternata is a risk factor for asthma. Few studies have examined Alternaria exposures in indoor environments., Objective: We examined whether exposure to A alternata in US homes was associated with asthma-related outcomes., Methods: The data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed a nationally representative sample of 831 housing units inhabited by 2456 individuals in 75 different locations throughout the United States. An interviewer-administered questionnaire obtained information on demographics, household characteristics, and occupants' health status. Exposure to A alternata was assessed by measuring concentrations of A alternata antigens in vacuumed dust samples using a polyclonal anti-A alternata antibody assay. Dust samples were collected from a bed, a sofa, or a chair, and from bedroom, living room, and kitchen floors., Results: Lifetime prevalence of doctor-diagnosed asthma was 11.2%, and 6.9% of the study subjects reported active asthma symptoms in the past 12 months. The prevalence of current symptomatic asthma increased with increasing Alternaria concentrations in US homes; higher levels of A alternata antigens increased the odds of having asthma symptoms in the past year (relative to the lowest tertile, adjusted odds ratio was 1.52, 95% CI, 0.90-2.55 for the 2nd tertile; and 1.84, 95% CI, 1.18-2.85 for the 3rd tertile)., Conclusion: Exposure to A alternata in US homes is associated with active asthma symptoms., Clinical Implications: Measures that reduce indoor exposure to A alternata may help control asthma exacerbations.

Unlabelled: We characterized the prevalence of cockroach allergen exposure in a nationally representative sample of U.S. homes and assessed risk factors for elevated concentrations., Design: We used data from the National Survey of Lead and Allergens in Housing, a population-based cross-sectional survey., Participants: Participants were residents of 831 U.S. homes in the survey., Evaluations/measurements: We analyzed allergen, questionnaire, and observational data of 831 U.S. homes., Results: Cockroach allergen (Bla g 1) concentrations exceed 2.0 U/g, a level associated with allergic sensitization, in 11% of U.S. living room floors and 13% of kitchen floors. Concentrations exceed 8.0 U/g, a level associated with asthma morbidity, in 3% of living room floors and 10% of kitchen floors. Elevated concentrations were observed in high-rise apartments, urban settings, pre-1940 constructions, and households with incomes < $20,000. Odds of having concentrations > 8.0 U/g were greatest when roach problems were reported or observed and increased with the number of cockroaches observed and with indications of recent cockroach activity., Conclusions: Household cockroach allergen exposure is characterized in a nationally representative context. The allergen is prevalent in many settings, at levels that may contribute to allergic sensitization and asthma morbidity., Relevance to Clinical or Professional Practice: Likelihood of exposure can be assessed by consideration of demographic and household determinants.

Background: Alternaria alternata is one of the most common fungi associated with allergic disease. However, Alternaria exposure in indoor environments is not well characterized., Objective: The primary goals of this study were to examine the prevalence of Alternaria exposure and identify independent predictors of Alternaria antigen concentrations in US homes., Methods: Data for this cross-sectional study were obtained from the National Survey of Lead and Allergens in Housing. A nationally representative sample of 831 housing units in 75 different locations throughout the United States completed the survey. Information on housing and household characteristics was obtained by questionnaire and environmental assessments. Concentrations of A alternata antigens in dust collected from various indoor sites were assessed with a polyclonal anti-Alternaria antibody assay., Results: Alternaria antigens were detected in most (95% to 99%) of the dust samples. The geometric mean concentration, reflecting the average Alternaria concentration in homes, was 4.88 microg/g (SEM, 0.13 microg/g). In the multivariable linear regression analysis, the age of the housing unit, geographic region, urbanization, poverty, family race, observed mold and moisture problems, use of de-humidifier, and presence of cats and dogs were independent predictors of Alternaria antigen concentrations. Less frequent cleaning and smoking indoors also contributed to higher Alternaria antigen levels in homes., Conclusion: Exposure to A alternata antigens in US homes is common. Antigen levels in homes are influenced not only by regional factors but also by residential characteristics. Preventing mold and moisture problems, avoiding smoking indoors, and regular household cleaning may help reduce exposure to Alternaria antigens indoors.

Background: Allergy skin tests were administered in the second and third National Health and Nutrition Examination Surveys (NHANES II and III) conducted in the United States from 1976 through 1980 and 1988 through 1994, respectively., Objectives: This study estimated positive skin test response rates in NHANES III and identified predictors of one or more positive test responses. Comparisons with NHANES II were also made., Methods: In NHANES III, 10 allergens and 2 controls were tested in all subjects aged 6 to 19 years and a random half-sample of subjects aged 20 to 59 years. A wheal-based definition of a positive test response was used., Results: In NHANES III, 54.3% of the population had positive test responses to 1 or more allergens. Prevalences were 27.5% for dust mite, 26.9% for perennial rye, 26.2% for short ragweed, 26.1% for German cockroach, 18.1% for Bermuda grass, 17.0% for cat, 15.2% for Russian thistle, 13.2% for white oak, 12.9% for Alternaria alternata, and 8.6% for peanut. Among those with positive test responses, the median number of positive responses was 3.0. Adjusted odds of a positive test response were higher for the following variables: age of 20 to 29 years, male sex, minority race, western region, old homes, and lower serum cotinine levels. For the 6 allergens common to NHANES II and III, prevalences were 2.1 to 5.5 times higher in NHANES III., Conclusions: The majority of the US population represented in NHANES III was sensitized to 1 or more allergens. Whether the higher prevalences observed in NHANES III reflect true changes in prevalence or methodological differences between the surveys cannot be determined with certainty.

Background: Exposures to dog and cat allergens are believed to play important roles in the etiology of asthma; however, the levels of these allergens have never been assessed in a representative sample of US homes., Objective: The objective of this study was to estimate and characterize exposures to Can f 1 (dog allergen) and Fel d 1 (cat allergen) in US homes., Methods: Data were obtained from the National Survey of Lead and Allergens in Housing, a nationally representative survey of 831 US homes. Vacuumed-collected dust samples from the bed, bedroom floor, living room floor, and living room sofa were analyzed for concentrations of Can f 1 and Fel d 1 (micrograms of allergen per gram of dust)., Results: Although a dog or cat had lived in only 49.1% of homes in the previous 6 months, Can f 1 and Fel d 1 were detected in 100% and 99.9% of homes, respectively. Averaged over the sampled sites, geometric mean concentrations (microg/g) were 4.69 for Can f 1 and 4.73 for Fel d 1. Among homes with an indoor dog and cat, respectively, geometric mean concentrations were 69 for Can f 1 and 200 for Fel d 1. Among homes without the indoor pet, geometric mean concentrations were above 1.0. The independent predictors of elevated concentrations in homes without pets were all demographic variables that were also linked to a higher prevalence of pet ownership., Conclusions: Can f 1 and Fel d 1 are universally present in US homes. Levels that have been associated with an increased risk of allergic sensitization were found even in homes without pets. Because of the transportability of these allergens on clothing, elevated levels in homes without pets, particularly among demographic groups in which pet ownership is more prevalent, implicate the community as an important source of these pet allergens.

Background: Exposure to mouse allergen is a known cause of asthma in occupational settings and exhibits high prevalence and association with allergic sensitization in inner-city home environments. It has never been characterized on a nationally representative scale., Objective: This study was designed to characterize mouse allergen prevalence in a representative sample of US homes and to assess risk factors for increased concentrations., Methods: Allergen, questionnaire, and observational data were analyzed from the first National Survey of Lead and Allergens in Housing, a cross-sectional survey of 831 US housing units. Allergen levels were characterized and related to demographic factors and household characteristics., Results: Detectable levels of mouse allergen (Mus m 1) exist in 82% of US homes. Kitchen floor concentrations exceed 1.6 microg/g, a level associated with increased sensitization rates, in 22% of homes. Increased concentrations (>1.6 microg/g) were observed in high-rise apartments and mobile homes, older homes, and low-income homes. Odds of having increased concentrations were increased when rodent (odds ratio [OR], 3.38) or cockroach (OR, 1.81) problems were reported and when floor mopping (OR, 2.17) was performed instead of vacuuming., Conclusions: Household mouse allergen is widespread in many settings at levels that might contribute to asthma morbidity. The likelihood of exposure can be assessed by consideration of demographic and household determinants.

Background: In the first 6 months of this previously published, randomized trial, the combined intervention of occupant education, insecticide bait application, and professional cleaning significantly reduced cockroach numbers and Bla g 1 allergen levels in inner-city homes., Objective: This continuation study investigated whether the cockroach allergen reductions achieved by month 6 could be maintained through month 12 with insecticide application alone., Methods: Because we had agreed to place insecticide bait in control homes at the conclusion of the first study, intervention and control homes were treated with insecticide bait at months 6 and 9. No other intervention was conducted in either arm. Vacuumed dust and swab samples were collected at month 12. Twenty-one of the 31 original homes completed the 12-month study., Results: Among the original intervention homes, Bla g 1 concentrations remained essentially unchanged from months 6 to 12. However, among the crossed-over control homes, the geometric mean Bla g 1 concentrations (Units per gram of dust) decreased from 287 to 14.4 for kitchen floors (95% reduction), from 28.8 to 5.6 for living room floors/sofas (81% reduction), from 26.7 to 4.7 for bedroom floors (82% reduction), and from 7.2 to 2.4 for beds (67% reduction). At month 12, Bla g 1 concentrations did not significantly differ between intervention and crossed-over control homes (P >.64 at each location). Similar results were seen for the allergen Bla g 2., Conclusions: Reductions in cockroach allergen concentrations achieved through the combined intervention of occupant education, insecticide application, and professional cleaning can be maintained with continued cockroach control. Surprisingly, and in contrast to other studies, insecticide application alone significantly lowered allergen concentrations in the crossed-over control homes. This unexpected result is being tested further in another randomized trial.

Background: Clinically relevant reductions in exposure to cockroach allergen, an important risk factor for asthma in inner-city households, have proven difficult to achieve in intervention trials., Objective: This study investigated a method for the abatement of cockroach allergen in low-income, urban homes. The goal was to reduce mean Bla g 1 concentrations below the previously proposed thresholds for allergic sensitization and asthma morbidity., Methods: A prerandomized, nonmasked trial with 16 intervention and 15 control homes was conducted. Study inclusion was based on 50 to 500 cockroaches trapped in a 3-day period. The interventions consisted of occupant education, placement of insecticide bait, and professional cleaning. Vacuumed dust and multiple swab samples were collected at 0, 1, 2, 4, and 6 months in intervention homes and at 0 and 6 months in control homes. Room maps containing cockroach and allergen data were used to guide and monitor the interventions., Results: From 0 to 6 months among intervention homes, geometric mean Bla g 1 concentrations (U/g dust) decreased from 633 to 24 on kitchen floors (96% reduction), from 25 to 4.3 on living room floors/sofas (83% reduction), from 46 to 7.3 on bedroom floors (84% reduction), and from 6.1 to 1.0 in bedroom beds (84% reduction). These reductions, with the exception of that on the bedroom floor (P =.06), were statistically significant relative to changes in control homes., Conclusions: Substantial reductions in cockroach allergen levels can be achieved in inner-city homes. In this study, allergen levels were reduced below the sensitization threshold (2 U/g) in beds, arguably the most relevant site for exposure, and below the asthma morbidity threshold (8 U/g) on bedroom floors and living room floors/sofas. The level on kitchen floors, although reduced 96%, remained above the asthma morbidity threshold. Future studies will test the intervention's effectiveness in asthma prevention trials.

In epidemiologic studies, there is often interest in assessing the association between exposure history and disease incidence. For many diseases, incidence may depend not only on cumulative exposure, but also on the ages at which exposure occurred. This article proposes a flexible Bayesian approach for modeling age-varying and waning exposure effects. The Cox model is generalized to allow the hazard of disease to depend on an integral, across the exposed ages, of a piecewise polynomial function of age, multiplied by an exponential decay term. Linearity properties of the model facilitate posterior computation via a Gibbs sampler, which generalizes previous algorithms for Cox regression with time-dependent covariates. The approach is illustrated by an application to the study of protective effects of breastfeeding on incidence of childhood asthma.

Background: Asthma prevalence has increased dramatically in recent years, especially among children. Breast-feeding might protect children against asthma and related conditions (recurrent wheeze), and this protective effect might depend on the duration and exclusivity of the breast-feeding regimen., Objective: We sought to determine whether there is an association between breast-feeding and asthma, recurrent wheeze, or both in children up to 72 months of age and whether the duration and exclusivity of breast-feeding affect this association., Methods: Data were from the third National Health and Nutrition Examination Survey, a nationally representative cross-sectional survey conducted from 1988 to 1994. We tested for significant associations between breast-feeding and physician-diagnosed asthma and recurrent wheeze (> or =3 episodes in the past 12 months) before and after adjusting for potential confounders., Results: Crude analyses showed that breast-feeding was associated with significantly reduced risks for asthma and recurrent wheeze in children 2 to 71 months of age, but after adjusting for potential confounders, these overall protective associations attenuated and were no longer statistically significant. However, 2 new and important associations were revealed after adjusting for confounders: (1) compared with never breast-fed children, ever breast-fed children had significantly reduced odds of being diagnosed with asthma and of having recurrent wheeze before 24 months of age, and (2) among children 2 to 71 months of age who had been exposed to environmental tobacco smoke, those who had ever been breast-fed had significantly reduced risks of asthma and wheeze compared with those who had never been breast-fed., Conclusions: Breast-feeding might delay the onset of or actively protect children less than 24 months of age against asthma and recurrent wheeze. Breast-feeding might reduce the prevalence of asthma and recurrent wheeze in children exposed to environmental tobacco smoke.

Background: Although exposure to house dust mite allergen is a major risk factor for allergic sensitization and asthma, nationwide estimates of dust mite allergen levels in US homes have not been reported., Objective: The purpose of this study was to estimate the prevalence of dust mite allergen in beds of US homes and to identify predictors of dust mite allergen concentration., Methods: Data were obtained from the first National Survey of Lead and Allergens in Housing, a cross-sectional survey of 831 permanently occupied noninstitutional housing units that permitted resident children. Dust mite allergen concentration (Der f 1 plus Der p 1) was determined from a dust sample collected from a bed. The percentages of homes with concentrations at or greater than detection, 2.0 microg/g bed dust, and 10.0 microg/g bed dust were estimated. Independent predictors of allergen concentration were assessed with multivariable linear regression., Results: The percentages of US homes with dust mite allergen concentrations at or greater than detection, 2.0 microg/g, and 10.0 microg/g were 84.2% (SE, 1.73), 46.2% (SE, 2.0), and 24.2% (SE, 2.1), respectively. Independent predictors of higher levels were older homes, non-West census regions, single-family homes, no resident children, lower household income, heating sources other than forced air, musty or mildew odor, and higher bedroom humidity., Conclusion: Most US homes have detectable levels of dust mite allergen in a bed. Levels previously associated with allergic sensitization and asthma are common in US bedrooms. Predictors can be used to identify conditions under which homes are more likely to have increased dust mite allergen levels.

From July 1998 to August 1999, the U.S. Department of Housing and Urban Development and the National Institute of Environmental Health Sciences conducted the first National Survey of Lead and Allergens in Housing. The purpose of the survey was to assess children's potential household exposure to lead, allergens, and bacterial endotoxins. We surveyed a sample of 831 homes, representing 96 million permanently occupied, noninstitutional housing units that permit resident children. We administered questionnaires to household members, made home observations, and took environmental samples. This article provides general background information on the survey, an overview of the survey design, and a description of the data collection and laboratory methods pertaining to the allergen and endotoxin components. We collected dust samples from a bed, the bedroom floor, a sofa or chair, the living room floor, the kitchen floor, and a basement floor and analyzed them for cockroach allergen Bla g 1, the dust mite allergens Der f 1 and Der p 1, the cat allergen Fel d 1, the dog allergen Can f 1, the rodent allergens Rat n 1 and mouse urinary protein, allergens of the fungus Alternaria alternata, and endotoxin. This article provides the essential context for subsequent reports that will describe the prevalence of allergens and endotoxin in U.S. households, their distribution by various housing characteristics, and their associations with allergic diseases such as asthma and rhinitis.

Objective: The purpose of this study was to identify factors that contribute to the poorer survival of blacks in the United States diagnosed with oral cancer., Methods: Data for 6,338 whites and 1,165 blacks diagnosed from 1988 to 1993 with squamous cell carcinoma of the oral cavity and pharynx were obtained from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program 1973-1993 Public-Use Database. The covariables were sex, age, geographic area, marital status, socioeconomic status (five census-tract measures), stage, anatomic site, grade, lymph node involvement, tumor size, and treatment. Hazard ratios were estimated with Cox regression., Results: Adjusted for age and geographic area, the hazard of death from oral cancer was 1.7 (95% confidence interval: 1.5-1.9) times greater among blacks than whites. The addition of the socioeconomic status (SES) variables to the model reduced the hazard ratio for race to 1.3 (1.0-1.7). Further adjustment by stage and treatment reduced the hazard ratio for race to 1.1 (0.9-1.4). In a model containing all covariables (except lymph node involvement and tumor size), the hazard ratio for race remained 1.1 (0.9-1.4). Analyses with the outcome death from any cause gave similar results., Conclusions: Lower SES, more advanced stage, and differences in treatment accounted for 86% of the excess hazard of death from oral cancer among blacks.

Coronary heart disease is responsible for one of every five deaths in the United States. Recent epidemiological studies have shown an association between periodontal disease and coronary heart disease. The purpose of this cross-sectional study was to verify this association using data from the third National Health and Nutrition Examination Survey (NHANES III). Data for 5564 people 40 years of age and older who had complete periodontal assessments and information on heart attack were evaluated. The outcome was the self-reported history of heart attack (yes vs. no). The main independent variable was the percent of periodontal sites per person with attachment loss of 3 mm or greater (categorized as 0%, > 0-33%, > 33-67%, and > 67%). Periodontal attachment loss was measured at two sites per tooth in randomly assigned half-mouths, one upper and one lower quadrant. The covariables included sociodemographic variables and established risk factors for cardiovascular disease. Relative to the 0% category, the unadjusted odds of heart attack increased with each higher category of attachment loss-2.2 (95% confidence interval = 1.3-3.8), 5.5 (3.4-9.1), and 9.8 (4.5-21.0), respectively. Adjustment for age, sex, race, poverty, smoking, diabetes, high blood pressure, body mass index, and serum cholesterol decreased these odds to 1.4 (0.8-2.5), 2.3 (1.2-4.4), and 3.8 (1.5-9.7), respectively. This study supports findings from previous studies of an association between periodontal disease and coronary heart disease.

A method for the determination of underivatized chlorophenols in human urine samples by combined high performance liquid chromatography mass spectrometry is described. Results obtained on individual samples are reported and compared with data obtained by alternative chromatographic methods.