The role of environmental tobacco smoke in the origins and progression of asthma

A Socioecological Mixture Model of Asthma Prevalence Among Sexual Minority Adults in the United States

Purpose: Sexual minority (SM) identity as well as sociodemographic and socioeconomic factors are associated with asthma prevalence. A syndemics framework analyzes disease conditions in a population and the social, economic, and environmental contexts in which they are found. We used a syndemic model of individual-level socioecological factors to identify profiles of asthma prevalence among SM adults. Methods: Latent class analysis (LCA) was conducted on a subpopulation of SM adults aged 18-59 years from the 2001 to 2016 National Health and Nutrition Examination Survey. Indicators in the LCA model included current asthma, gender, sexual identity, poverty-income ratio, education, and serum cotinine level. Multinomial logistic regression analyzed the effects of covariates (race/ethnicity, nativity, age, marital status, body mass index, lifetime smoking, and mental health care seeking) on identified profiles. Results: Four classes were identified among our sample of n = 1097 SM adults. Classes 1 and 2 had 19% and 18% conditional probabilities of current asthma, respectively, and were primarily female and bisexual. Classes 3 and 4 had 5% and 2% conditional probabilities of asthma, respectively, and were primarily male and gay. Classes 1 and 3 also had conditional probabilities of high income and educational attainment. Black individuals had higher odds than White individuals of being in Class 1 (odds ratio [OR] = 4.46, 95% confidence interval [CI] = 1.43-13.93), Class 2 (OR = 21.66, 95% CI = 7.50-62.60), and Class 4 (OR = 7.41, 95% CI = 2.05-26.71), relative to Class 3. Conclusion: Findings extend past literature that suggests within-group asthma disparities among SM adults. Informational campaigns on asthma management should target this community to avoid severe disease exacerbations.

Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis

It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).

New perspectives in bronchial asthma: pathological, immunological alterations, biological targets, and pharmacotherapy

Asthma is the most common, long-lasting inflammatory airway disease that affects more than 10% of the world population. It is characterized by bronchial narrowing, airway hyperresponsiveness, vasodilatation, airway edema, and stimulation of sensory nerve endings that lead to recurring events of breathlessness, wheezing, chest tightness, and coughing. It is the main reason for global morbidity and occurs as a result of the weakening of the immune system in response to exposure to allergens or environmental exposure. In asthma condition, it results in the activation of numerous inflammatory cells like the mast and dendritic cells along with the accumulation of activated eosinophils and lymphocytes at the inflammation site. The structural cells such as airway epithelial cells and smooth muscle cells release inflammatory mediators that promote the bronchial inflammation. Long-lasting bronchial inflammation can cause pathological alterations, viz. the improved thickness of the bronchial epithelium and friability of airway epithelial cells, epithelium fibrosis, hyperplasia, and hypertrophy of airway smooth muscle, angiogenesis, and mucus gland hyperplasia. The stimulation of bronchial epithelial cell would result in the release of inflammatory cytokines and chemokines that attract inflammatory cells into bronchial airways and plays an important role in asthma. Asthma patients who do not respond to marketed antiasthmatic drugs needed novel biological medications to regulate the asthmatic situation. The present review enumerates various types of asthma, etiological factors, and in vivo animal models for the induction of asthma. The underlying pathological, immunological mechanism of action, the role of inflammatory mediators, the effect of inflammation on the bronchial airways, newer treatment approaches, and novel biological targets of asthma have been discussed in this review.

Smoking history is negatively associated with allergen specific immunotherapy efficacy: a retrospective analysis

Introduction

Allergen specific immunotherapy (AIT) is the only treatment modifying the course of the disease in patients allergic to airborne allergens. It has been proven to be effective in allergic populations, however individual patients vary in terms of response to the therapy.

Aim

To assess the factors that might affect the efficacy of AIT.

Material and methods

Patients treated with AIT for grass pollen or house dust mites were included. The efficacy of AIT was assessed with the use of Allergy Control Score (ACS), performed before and at least 1 year after AIT. The following variables were assessed as potential risk factors for a worse response to AIT: age, gender, type of allergy, type of allergen, type of vaccine, type of AIT and smoking history.

Results

The study group consisted of 145 subjects.AIT was effective in the entire group; the mean ACS results decreased from 21.14 to 14.41 points (p< 0.0001). No differences in efficacy in terms of assessed risk factors were found, except for smoking history (ACS change in the smoking group was smaller: from 21.8 to 18.1 points; p = 0.09, OR = 0.323; 95% CI: 0.11-0.88; p = 0.02).

Conclusions

Smoking history may affect AIT outcomes.

Parental Depression is Prospectively Associated With Lower Smoking Cessation Rates and Poor Child Asthma Outcomes

Background

Depressive symptoms are elevated in parents of asthmatic children compared with parents of healthy children. The role of depression in smoking cessation and pediatric asthma outcomes in this population is unclear.

Purpose

To prospectively examine the effect of parent depression on smoking cessation and child asthma outcomes.

Methods

Secondary analysis from a cessation induction trial involving Motivational Interviewing (MI) and biomarker feedback on secondhand smoke exposure (SHSe). Parents (n=341) had an asthmatic child (mean age=5.2 years) and did not have to want to quit smoking to enroll. Intervention included asthma education, MI, and SHSe feedback plus randomization to six counseling (MI; repeated feedback) or control calls (brief check on asthma) for 4 months. Depressive symptoms were defined as scoring ≥22 on the Center for Epidemiologic Study-Depression scale. Smoking outcomes were bioverified 7- and 30-day point-prevalence abstinence (ppa). Child asthma outcomes were past month functional limitation, health care utilization, and number of days with asthma symptoms. Data were obtained at baseline, 2, 4, and 6 months.

Results

Parental depression was associated with lower odds of abstinence (7-day ppa odds ratio [OR]=0.38, 95% confidence interval [CI]=0.23, 0.64; 30-day ppa OR=0.27, 95% CI=0.15, 0.47), greater odds of child health care utilization for asthma (OR=1.71, 95% CI=1.01, 2.92), and greater child asthma functional limitation (B=0.16, SE=0.06, p=.03) even after controlling for smoking status. Depression predicted a greater number of child asthma symptom days (B=1.08, SE=0.44, p=.01), but this became nonsignificant after controlling for smoking status.

Conclusions

Among parents who smoke, both depressive symptoms and smoking should be targeted for treatment aimed at improving pediatric asthma.

Longitudinal Effect of Ambient Air Pollution and Pollen Exposure on Asthma Control: The Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Asthma Study

OBJECTIVE

Although exposure to air pollution and pollen is associated with asthma exacerbation and increased health care use, longitudinal effects of fine particulate matter 2.5 (PM_2.5), ozone (O₃), and pollen exposure on asthma control status in pediatric patients are understudied. This study investigated effects of exposure to PM_2.5, O₃, and pollen on asthma control status among pediatric patients with asthma.

METHODS

A total of 229 dyads of pediatric patients with asthma and their parents were followed for 15 months. The Asthma Control and Communication Instrument was used to measure asthma control, which was reported weekly by parents during a 26-week period. PM_2.5 and O₃ data were collected from the US Environmental Protection Agency Air Quality System. Pollen data were obtained from Intercontinental Marketing Services Health. Mean air pollutant and pollen exposures within 7 days before the reporting of asthma control were used to estimate weekly exposures for each participant. Linear mixed-effects models were performed to test associations of PM_2.5, O₃, and pollen exposure with asthma control status. Sensitivity analyses were performed to evaluate the robustness of findings by different exposure monitoring days per week and distances between monitoring sites and participants' residences.

RESULTS

Elevated PM_2.5 concentration and pollen severity were associated with poorer asthma control status (P < .05), yet elevated O₃ concentration was marginally associated with better asthma control (P < .1).

CONCLUSIONS

Poorer asthma control status was associated with elevated PM_2.5 and pollen severity. Reducing harmful outdoor environmental ambient exposure may improve asthma outcomes in children and adolescents.

Severity and prevalence of allergic rhinitis among school children, Jazan Region Saudi Arabia

Background:

Allergic diseases such as allergic rhinitis (AR) represent a global health problem, affecting 10–25% of the world population. There is clear evidence to support the concept that allergic diseases are influenced by genetic predisposition and environmental exposure.

Objectives:

To assess the severity and prevalence of AR among school children in Jazan Region, Saudi Arabia.

Methods:

This is a cross-sectional study using a modified International Study of Asthma and Allergies in Children (ISAAC) questionnaire.

Results:

The nasal blocking is considered to be one of the most common symptoms of AR. Regarding the frequency of AR-related symptoms which indicate severity in the last 12 months according to the gender, our statistical analysis results found that the severity regarding nasal symptoms varied from nasal block to disturbed sleep due to nasal block where 97 (6.9%) had nasal block, 109 (7.8%) had nasal block interfering with daily activities, 12.1% had nasal block resulting in breathing difficulties, and 67 (4.7%) had disturbed sleep due to nasal block/problem. About 258 (18.4%) of all population urgently visited the emergency department due to nasal problems. Sixty-four (4.5%) were admitted due to nasal problems and 92 (6.6%) missed school days due to nasal block. The prevalence in elementary and intermediate school was 209 (14.9) and 170 (12.2), respectively with P value of 0.013, according to gender of study population showed no statistical significance according to all parameters. The prevalence was higher among Saudi population, regarding education level the prevalence was higher among intermediate school children.

Conclusion:

In conclusion, it was clear that the prevalence of AR among Saudi school children is 27.1%. Living in urban areas, intermediate school education level, lowlander population are significant risk factors for the prevalence and severity of AR.

Cigarette Smoke Increases CD8α+ Dendritic Cells in an Ovalbumin-Induced Airway Inflammation

Asthma is an allergic lung disease and, when associated to cigarette smoke exposition, some patients show controversial signs about lung function and other inflammatory mediators. Epidemiologic and experimental studies have shown both increasing and decreasing inflammation in lungs of subjects with asthma and exposed to cigarette smoke. Therefore, in this study, we analyzed how cigarette smoke affects pro-inflammatory and anti-inflammatory mediators in a murine model of allergic pulmonary inflammation. We sensitized Balb/c mice to ovalbumin (OVA) with two intraperitoneal injections. After sensitization, the animals were exposed to cigarette smoke twice a day, 30 min per exposition, for 12 consecutive days. In order to drive the cell to the lungs, four aerosol challenges were performed every 48 h with the same allergen of sensitization. OVA sensitization and challenge developed pulmonary Th2 characteristic response with increased airway responsiveness, remodeling, increased levels of IgE, interleukin (IL)-4, and IL-13. Cigarette smoke, unexpectedly, reduced the levels of IL-4 and IL-13 and simultaneously decreased anti-inflammatory cytokines as IL-10 and transforming growth factor (TGF)-β in sensitized and challenged animals. OVA combined with cigarette smoke exposition decreased the number of eosinophils in bronchoalveolar lavage and increased the number of neutrophils in lung. The combination of cigarette smoke and lung allergy increased recruitment of lymphoid dendritic cells (DCs) into lymph nodes, which may be the leading cause to an increase in number and activation of CD8⁺ T cells in lungs. In addition, lung allergy and cigarette smoke exposure decreased an important regulatory subtype of DC such as plasmacytoid DC as well as its activation by expression of CD86, PDL2, and ICOSL, and it was sufficient to decrease T regs influx and anti-inflammatory cytokines release such as IL-10 and TGF-β but not enough to diminish the structural changes. In conclusion, we observed, in this model, that OVA sensitization and challenge combined with cigarette smoke exposure leads to mischaracterization of the Th2 response of asthma by decreasing the number of eosinophils, IL-4, and IL-13 and increasing number of neutrophils, which is related to the increased number of CD8ɑ⁺ DCs and CD8⁺ T cells as well as reduction of the regulatory cells and its released cytokines.

Functional Effects of Cigarette Smoke-Induced Changes in Airway Smooth Muscle Mitochondrial Morphology

Long-term exposure to cigarette smoke (CS) triggers airway hyperreactivity and remodeling, effects that involve airway smooth muscle (ASM). We previously showed that CS destabilizes the networked morphology of mitochondria in human ASM by regulating the expression of mitochondrial fission and fusion proteins via multiple signaling mechanisms. Emerging data link regulation of mitochondrial morphology to cellular structure and function. We hypothesized that CS-induced changes in ASM mitochondrial morphology detrimentally affect mitochondrial function, leading to CS effects on contractility and remodeling. Here, ASM cells were exposed to 1% cigarette smoke extract (CSE) for 48 h to alter mitochondrial fission/fusion, or by inhibiting the fission protein Drp1 or the fusion protein Mfn2. Mitochondrial function was assessed via changes in bioenergetics or altered rates of proliferation and apoptosis. Our results indicate that both exposure to CS and inhibition of mitochondrial fission/fusion proteins affect mitochondrial function (i.e., energy metabolism, proliferation, and apoptosis) in ASM cells. In vivo, the airways in mice chronically exposed to CS are thickened and fibrotic, and the expression of proteins involved in mitochondrial function is dramatically altered in the ASM of these mice. We conclude that CS-induced changes in mitochondrial morphology (fission/fusion balance) correlate with mitochondrial function, and thus may control ASM proliferation, which plays a central role in airway health. J. Cell. Physiol. 232: 1053-1068, 2017. © 2016 Wiley Periodicals, Inc.

Inhaled medication usage in post-menopausal women and lifetime tobacco smoke exposure: The Women's Health Initiative Observational Study

OBJECTIVE

While active smoking is a causal agent in respiratory disease, the independent role of secondhand smoke (SHS) merits further investigation. We investigated associations between lifetime active smoking and exposure to secondhand smoke - studied independently - and current use of 1 or more inhaled medications as a surrogate for prevalent pulmonary disease in post-menopausal women.

STUDY DESIGN

Information on lifetime active and passive tobacco exposure and inhaled pulmonary medication usage at enrollment was collected from 88,185 postmenopausal women aged 50-79 enrolled in the Women's Health Initiative Observational Study from 1993 to 1998 at 40 centers in the United States. Participants were recruited from localities surrounding the study centers using a variety of methods, including informational mailings and mass media campaigns.

MAIN OUTCOME MEASURES

Multivariate adjusted regression models were used to estimate odds ratios and 95% CI according to levels of active smoking and SHS exposure, and trends were tested across categories.

RESULTS

Ever active smokers had an overall OR of 1.97 (95% CI 1.58-2.45) for having one or more prescribed inhaled medication compared with never-smoking women not exposed to active or passive smoke. The overall OR for using inhalers for never-smoking women exposed to any SHS compared with the same reference group was 1.33 (95% CI 1.07-1.65). In a quantified analysis of SHS, never-smoking women with the highest levels of lifetime SHS exposure had an estimated risk of inhaled medication usage of 1.74 (95% CI 1.32-2.30).

CONCLUSIONS

The risk of requiring one or more prescribed inhaled medications for pulmonary disease was significantly higher in post-menopausal women who ever smoked or who had lifetime exposure to SHS.

Child maltreatment and pediatric asthma: a review of the literature

BACKGROUND

Child maltreatment is a common problem with known adverse consequences, yet its contributions to the development and course of pediatric asthma are only poorly understood.

MAIN

This review first describes possible pathways connecting child maltreatment to pediatric asthma, including aspects of the physical home environment, health behaviors and disease management, and psychological consequences of child maltreatment. We subsequently review existing studies, which generally report an association between maltreatment experiences and asthma outcomes in childhood. However, this literature is in its early stages; there are only a handful studies, most of them rely on self-reports of both child maltreatment and asthma history, and none have investigated the physiological underpinnings of this association. Taken together, however, the studies are suggestive of child maltreatment playing a role in pediatric asthma incidence and expression that should be explored further.

CONCLUSION

Existing data are sparse and do not allow for specific conclusions. However, the data are suggestive of child maltreatment influencing asthma risk and morbidity long before the adult years. Future research should focus on understanding how child maltreatment contributes to asthma disease risk and progression in this highly vulnerable population.

Childhood Asthma Management and Environmental Triggers

Asthma is the most common chronic disease among children. It cannot be prevented but can be controlled. Industrialized countries experience high lifetime asthma prevalence that has increased over recent decades. Asthma has a complex interplay of genetic and environmental triggers. Studies have revealed complex interactions of lung structure and function genes with environmental exposures such as environmental tobacco smoke and vitamin D. Home environmental strategies can reduce asthma morbidity in children but should be tailored to specific allergens. Coupled with education and severity-specific asthma therapy, tailored interventions may be the most effective strategy to manage childhood asthma.

Update on epigenetics in allergic disease

Chronic inflammatory diseases, including allergies and asthma, are the result of complex gene-environment interactions. One of the most challenging questions in this regard relates to the biochemical mechanism of how exogenous environmental trigger factors modulate and modify gene expression, subsequently leading to the development of chronic inflammatory conditions. Epigenetics comprises the umbrella of biochemical reactions and mechanisms, such as DNA methylation and chromatin modifications on histones and other structures. Recently, several lifestyle and environmental factors have been investigated in terms of such biochemical interactions with the gene expression-regulating machinery: allergens; microbes and microbial compounds; dietary factors, including vitamin B12, folic acid, and fish oil; obesity; and stress. This article aims to update recent developments in this context with an emphasis on allergy and asthma research.

Asthma, allergy and eczema among adults in multifamily houses in Stockholm (3-HE study)--associations with building characteristics, home environment and energy use for heating

Risk factors for asthma, allergy and eczema were studied in a stratified random sample of adults in Stockholm. In 2005, 472 multifamily buildings (10,506 dwellings) were invited (one subject/dwelling) and 7,554 participated (73%). Associations were analyzed by multiple logistic regression, adjusting for gender, age, smoking, country of birth, income and years in the dwelling. In total, 11% had doctor's diagnosed asthma, 22% doctor's diagnosed allergy, 23% pollen allergy and 23% eczema. Doctor's diagnosed asthma was more common in dwellings with humid air (OR = 1.74) and mould odour (OR = 1.79). Doctor's diagnosed allergy was more common in buildings with supply exhaust air ventilation as compared to exhaust air only (OR = 1.45) and was associated with redecoration (OR = 1.48) and mould odour (OR = 2.35). Pollen allergy was less common in buildings using more energy for heating (OR = 0.75) and was associated with humid air (OR = 1.76) and mould odour (OR = 2.36). Eczema was more common in larger buildings (OR 1.07) and less common in buildings using more energy for heating (OR = 0.85) and was associated with water damage (OR = 1.47), humid air (OR = 1.73) and mould odour (OR = 2.01). Doctor's diagnosed allergy was less common in buildings with management accessibility both in the neighbourhood and in larger administrative divisions, as compared to management in the neighbourhood only (OR = 0.49; 95% CI 0.29-0.82). Pollen allergy was less common if the building maintenance was outsourced (OR = 0.67; 95% CI 0.51-0.88). Eczema was more common when management accessibility was only at the division level (OR = 1.49; 95% CI 1.06-2.11). In conclusions, asthma, allergy or eczema were more common in buildings using less energy for heating, in larger buildings and in dwellings with redecorations, mould odour, dampness and humid air. There is a need to reduce indoor chemical emissions and to control dampness. Energy saving may have consequences for allergy and eczema. More epidemiological studies are needed on building management organization.

Physician-prescribed Asthma Treatment Regimen does not differ Between Smoking and Non-smoking Patients With Asthma in Seoul and Gyunggi province of Korea

Purpose

Smoking has detrimental effects on asthma symptom control and response to treatment and is prevalent among asthma patients in South Korea. The aim of this study is to determine the prevalence of smoking among asthma patients in South Korea and to compare the medication regimens of asthma patients who do and do not smoke.

Methods

A cross-sectional survey was conducted from August 2010 to January 2011. Participating physicians (N=25) recorded demographic and clinical data on all asthma patients presenting during the study period (N=2,032), and then recruited a subset of patients (N=500) for the survey such that half were self-reported current smokers. Recruited patients were between the ages of 18 and 60.

Results

Among presenting asthma patients, 17.3% were current smokers, 19.2% were former smokers, and 63.5% had never smoked. Within the analyzable study population (N=471), 212 patients reported smoking currently, 79 smoking formerly, and 180 never smoking. Among current and former smokers, 79.7% and 81.0%, respectively, were men, while women represented 80.5% of patients who had never smoked. Agreement was strong between physician-determined smoking status and patient-reported smoking status (κ=0.82; P<0.001). However, asthma medication regimens examined according to GINA treatment steps did not differ by smoking status. In addition, mean quality of life scores and level of asthma control did not differ by smoking status.

Conclusions

In South Korea, physicians are well aware of the smoking status of their patients. However, smoking status did not affect the prescribed medication regimens of this population of asthma patients.

Epigenetic regulation: the interface between prenatal and early-life exposure and asthma susceptibility

Asthma is a complex disease with genetic and environmental influences and emerging evidence suggests that epigenetic regulation is also a major contributor. Here, we focus on the developing paradigm that epigenetic dysregulation in asthma and allergy may start as early as in utero following several environmental exposures. We summarize the pathways important to the allergic immune response that are epigenetically regulated, the key environmental exposures associated with epigenetic changes in asthma genes, and newly identified epigenetic biomarkers that have been linked to clinical asthma. We conclude with a brief discussion about the potential to apply newly developing technologies in epigenetics to the diagnosis and treatment of asthma and allergy. The inherent plasticity of epigenetic regulation following environmental exposures offers opportunities for prevention using environmental remediation, measuring novel biomarkers for early identification of those at risk, and applying advances in pharmaco-epigenetics to tailor medical therapies that maximize efficacy of treatment. 'Precision Medicine' in asthma and allergy is arriving. As the field advances this may involve an individually tailored approach to the prevention, early detection, and treatment of disease based on the knowledge of an individual's epigenetic profile.

Role of the aryl hydrocarbon receptor (AhR) in lung inflammation

Millions of individuals worldwide are afflicted with acute and chronic respiratory diseases, causing temporary and permanent disabilities and even death. Oftentimes, these diseases occur as a result of altered immune responses. The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, acts as a regulator of mucosal barrier function and may influence immune responsiveness in the lungs through changes in gene expression, cell-cell adhesion, mucin production, and cytokine expression. This review updates the basic immunobiology of the AhR signaling pathway with regards to inflammatory lung diseases such as asthma, chronic obstructive pulmonary disease, and silicosis following data in rodent models and humans. Finally, we address the therapeutic potential of targeting the AhR in regulating inflammation during acute and chronic respiratory diseases.

Correlates of smoking during an economic recession among parents of children with asthma

OBJECTIVE

We describe the correlates of smoking among parents who have a child with asthma and examine whether the correlates changed from 2008 to 2010, when the United States experienced a severe recession and a sharp increase in unemployment, a stressor that could influence smoking behavior.

METHODS

Data are from the 2008 and 2010 Behavioral Risk Factor Surveillance System (BRFSS), a nationally representative survey of U.S. adults age 18 and older. Separate logistic regressions estimated the association between unemployment and smoking in 2008 and 2010, adjusting for sociodemographic and other characteristics of parents of a child with asthma.

RESULTS

Being unemployed was a significant predictor of smoking in 2010 (AOR = 1.80; 95% CI: 1.24-2.61), but was not a significant predictor in 2008 (AOR = 1.26, 95% CI: 0.82-1.95). One central component of well-being, as measured by being dissatisfied with one's life, was significantly associated with parental smoking in 2010 (AOR = 2.06, 95% CI: 1.00-4.27), but not in 2008 (AOR = 1.62, 95% CI: 0.85-3.11). Several covariates had similar associations with parental smoking in both survey years, including low education, not being currently married, not having health insurance, and binge drinking.

CONCLUSIONS

Our results support the idea that during hard economic times unemployment and related stressors may be strong determinants of parental smoking when a child in the home has asthma. Given that the BFRSS is a cross-sectional survey, definitive conclusions cannot be drawn regarding the causal pathway connecting unemployment, global well-being, and parental smoking.

Asthma discordance in twins is linked to epigenetic modifications of T cells

T cells mediate the inflammatory responses observed in asthma among genetically susceptible individuals and have been suspected to be prone to epigenetic regulation. However, these relationships are not well established from past clinical studies that have had limited capacity to control for the effects of variable genetic predisposition and early environmental exposures. Relying on a cohort of monozygotic twins discordant for asthma we sought to determine if epigenetic modifications in T cells were associated with current asthma and explored whether such modifications were associated with second hand smoke exposures. Our study was conducted in a monozygotic twin cohort of adult twin pairs (n = 21) all discordant for asthma. Regulatory T cell (Treg) and effector T cell (Teff) subsets were assessed for levels of cellular function, protein expression, gene expression and CpG methylation within Forkhead box P3 (FOXP3) and interferon gamma-γ (IFNγ) loci. Comparisons by asthma and current report of exposure to second hand smoke were made. Treg from asthmatic discordant twins demonstrated decreased FOXP3 protein expression and impaired Treg function that was associated with increased levels of CpG methylation within the FOXP3 locus when compared to their non-asthmatic twin partner. In parallel, Teff from discordant asthmatic twins demonstrated increased methylation of the IFNγ locus, decreased IFNγ expression and reduced Teff function when compared to Teff from the non-asthmatic twin. Finally, report of current exposure to second hand smoke was associated with modifications in both Treg and Teff at the transcriptional level among asthmatics. The results of the current study provide evidence for differential function of T cell subsets in monozygotic twins discordant for asthma that are regulated by changes in DNA methylation. Our preliminary data suggest exposure to second hand smoke may augment the modified T cell responses associated with asthma.

Socioeconomic status and the health of youth: a multilevel, multidomain approach to conceptualizing pathways

Previous research has clearly established associations between low socioeconomic status (SES) and poor youth physical health outcomes. This article provides an overview of the main pathways through which low SES environments come to influence youth health. We focus on 2 prevalent chronic health problems in youth today, asthma and obesity. We review and propose a model that encompasses (a) multiple levels of influence, including the neighborhood, family and person level; (b) both social and physical domains in the environment; and finally (c) dynamic relationships between these factors. A synthesis of existing research and our proposed model draw attention to the notion of adverse physical and social exposures in youth's neighborhood environments altering family characteristics and youth psychosocial and behavioral profiles, thereby increasing youth's risk for health problems. We also note the importance of acknowledging reciprocal influences across levels and domains (e.g., between family and child) that create self-perpetuating patterns of influence that further accentuate the impact of these factors on youth health. Finally, we document that factors across levels can interact (e.g., environmental pollution levels with child stress) to create unique, synergistic effects on youth health. Our model stresses the importance of evaluating influences on youth's physical health not in isolation but in the context of the broader social and physical environments in which youth live. Understanding the complex relationships between the factors that link low SES to youth's long-term health trajectories is necessary for the creation and implementation of successful interventions and policies to ultimately reduce health disparities.

Particle Concentrations and Effectiveness of Free-Standing Air Filters in Bedrooms of Children with Asthma in Detroit, Michigan

Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child's bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one-week period, we measured PM, carbon dioxide (CO(2)), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 µg m(-3), number concentrations averaged 70,777 and 1,471 L(-1) in 0.3-1.0 and 1-5 µm size ranges, respectively, and the median CO(2) concentration was 1,018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 µg m(-3). Filter use reduced PM concentrations by an average of 69 to 80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters.

Ethnic variability in persistent asthma after in utero tobacco exposure

BACKGROUND

The effects of in utero tobacco smoke exposure on childhood respiratory health have been investigated, and outcomes have been inconsistent.

OBJECTIVE

To determine if in utero tobacco smoke exposure is associated with childhood persistent asthma in Mexican, Puerto Rican, and black children.

PATIENTS AND METHODS

There were 295 Mexican, Puerto Rican, and black asthmatic children, aged 8 to 16 years, who underwent spirometry, and clinical data were collected from the parents during a standardized interview. The effect of in utero tobacco smoke exposure on the development of persistent asthma and related clinical outcomes was evaluated by logistic regression.

RESULTS

Children with persistent asthma had a higher odds of exposure to in utero tobacco smoke, but not current tobacco smoke, than did children with intermittent asthma (odds ratio [OR]: 3.57; P = .029). Tobacco smoke exposure from parents in the first 2 years of life did not alter this association. Furthermore, there were higher odds of in utero tobacco smoke exposure in children experiencing nocturnal symptoms (OR: 2.77; P = .048), daily asthma symptoms (OR: 2.73; P = .046), and emergency department visits (OR: 3.85; P = .015) within the year.

CONCLUSIONS

Exposure to tobacco smoke in utero was significantly associated with persistent asthma among Mexican, Puerto Rican, and black children compared with those with intermittent asthma. These results suggest that smoking cessation during pregnancy may lead to a decrease in the incidence of persistent asthma in these populations.

Do indoor environments influence asthma and asthma-related symptoms among adults in homes?: a review of the literature

This review summarizes the results of epidemiological studies focusing on the detrimental effects of home environmental factors on asthma morbidity in adults. We reviewed the literature on indoor air quality (IAQ), physical and sociodemographic factors, and asthma morbidity in homes, and identified commonly reported asthma, allergic, and respiratory symptoms involving the home environment. Reported IAQ and asthma morbidity data strongly indicated positive associations between indoor air pollution and adverse health effects in most studies. Indoor factors most consistently associated with asthma and asthma-related symptoms in adults included fuel combustion, mold growth, and environmental tobacco smoke. Environmental exposure may increase an adult's risk of developing asthma and also may increase the risk of asthma exacerbations. Evaluation of present IAQ levels, exposure characteristics, and the role of exposure to these factors in relation to asthma morbidity is important for improving our understanding, identifying the burden, and for developing and implementing interventions aimed at reducing asthma morbidity.

Economic value of home-based, multi-trigger, multicomponent interventions with an environmental focus for reducing asthma morbidity a community guide systematic review

CONTEXT

A recent systematic review of home-based, multi-trigger, multicomponent interventions with an environmental focus showed their effectiveness in reducing asthma morbidity among children and adolescents. These interventions included home visits by trained personnel to assess the level of and reduce adverse effects of indoor environmental pollutants, and educate households with an asthma client to reduce exposure to asthma triggers. The purpose of the present review is to identify economic values of these interventions and present ranges for the main economic outcomes (e.g., program costs, benefit-cost ratios, and incremental cost-effectiveness ratios).

EVIDENCE ACQUISITION

Using methods previously developed for Guide to Community Preventive Services economic reviews, a systematic review was conducted to evaluate the economic efficiency of home-based, multi-trigger, multicomponent interventions with an environmental focus to improve asthma-related morbidity outcomes. A total of 1551 studies were identified in the search period (1950 to June 2008), and 13 studies were included in this review. Program costs are reported for all included studies; cost-benefit results for three; and cost-effectiveness results for another three. Information on program cost was provided with varying degrees of completeness: six of the studies did not provide a list of components included in their program cost description (limited cost information), three studies provided a list of program cost components but not a cost per component (partial cost information), and four studies provided both a list of program cost components and costs per component (satisfactory cost information).

EVIDENCE SYNTHESIS

Program costs per participant per year ranged from $231-$14,858 (in 2007 U.S.$). The major factors affecting program cost, in addition to completeness, were the level of intensity of environmental remediation (minor, moderate, or major), type of educational component (environmental education or self-management), the professional status of the home visitor, and the frequency of visits by the home visitor. Benefit-cost ratios ranged from 5.3-14.0, implying that for every dollar spent on the intervention, the monetary value of the resulting benefits, such as averted medical costs or averted productivity losses, was $5.30-$14.00 (in 2007 U.S.$). The range in incremental cost-effectiveness ratios was $12-$57 (in 2007 U.S.$) per asthma symptom-free day, which means that these interventions achieved each additional symptom-free day for net costs varying from $12-$57.

CONCLUSIONS

The benefits from home-based, multi-trigger, multicomponent interventions with an environmental focus can match or even exceed their program costs. Based on cost-benefit and cost-effectiveness studies, the results of this review show that these programs provide a good value for dollars spent on the interventions.

Exhaled NO among inner-city children in New York City

BACKGROUND

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

OBJECTIVES

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

METHODS

As part of a longitudinal study of asthma, children recruited in Head Start centers at age 4 had offline FeNO and lung function testing at age 7. Children with allergen-specific immunoglobulin E (IgE) (≥0.35 IU/mL) at age 7 were considered seroatopic. ETS exposure at ages 4 and 7 was assessed by questionnaire.

RESULTS

Of 144 participating children, 89 had complete questionnaire data and achieved valid FeNO and lung function tests. Children with reported wheeze in the previous 12 months (n = 19) had higher FeNO than those without wheeze (n = 70) (geometric means 17.0 vs. 11.0 ppb, p = .005). FeNO remained significantly associated with wheeze (p = .031), after adjusting for seroatopy and forced expiratory volume in 1 second (FEV₁) in multivariable regression. FeNO at age 7 was positively associated with domestic ETS exposure at age 4 (29%) (β = 0.36, p = .015) but inversely associated with ETS exposure at age 7 (16%) (β = -0.74, p < .001).

CONCLUSIONS

Given its association with current wheeze, independent of seroatopy and lung function, FeNO provides a relevant outcome measure for studies in inner-city communities. While compelling, the positive association between ETS exposure at age 4 and a marker of airway inflammation at age 7 should be confirmed in a larger study.

Paediatric asthma in North Africa: the Asthma Insights and Reality in the Maghreb (AIRMAG) study

BACKGROUND

Bronchial asthma is the most frequent chronic childhood disease and can have a marked impact on educational development, activities and quality of life. The AIRMAG survey provides an opportunity to assess asthma and its impact in children in North Africa.

OBJECTIVE

To describe the prevalence, burden and management of asthma in children in the Maghreb.

METHODS

A general population sample was generated using a stratified sampling method based on randomly-generated lists of telephone numbers. The target sample consisted of 10,000 households in each country, which were contacted by telephone. A structured interview was proposed. Two screening questions were asked to identify subjects with asthma. Children who met these criteria were then questioned in more detail about their asthma.

RESULTS

Of 30,350 households contacted, 1090 subjects with asthma were identified, of whom 248 were aged under sixteen and interviewed by proxy. The prevalence of paediatric asthma ranged from 3.5% in Tunisia to 4.4% in Morocco. 22.8% of children were rated as severe persistent and 30.9% as intermittent. Asthma control was adequate in 7.6% of children and unacceptable in 46.2%. Control was best in Tunisia and worst in Morocco. 12.2% had been hospitalised for their asthma in the previous year and 32.9% had needed to attend an emergency department. Short-acting beta-agonists were used by 52.8% of children and prophylactic inhaled corticosteroids (alone or in association with long-acting beta-agonists) by 27.0%.

CONCLUSIONS

Asthma has a major impact on the lives of children with asthma in the Maghreb. This could be improved by offering more appropriate care as recommended in the GINA guidelines.

Tobacco smoking in seven Latin American cities: the CARMELA study

Objective

This study aimed to explore tobacco smoking in seven major cities of Latin America.

Methods

The Cardiovascular Risk Factor Multiple Evaluation in Latin America (CARMELA) study is a cross-sectional epidemiological study of 11 550 adults between 25 and 64 years old in Barquisimeto, Venezuela; Bogota, Colombia; Buenos Aires, Argentina; Lima, Peru; Mexico City, Mexico; Quito, Ecuador; and Santiago, Chile. Tobacco smoking, including cigarettes, cigars and pipes, was surveyed among other cardiovascular risk factors.

Results

Santiago and Buenos Aires had the highest smoking prevalence (45.4% and 38.6%, respectively); male and female rates were similar. In other cities, men smoked more than women, most markedly in Quito (49.4% of men vs 10.5% of women). Peak male smoking prevalence occurred among the youngest two age groups (25–34 and 35–44 years old). Men and women of Buenos Aires smoked the highest number of cigarettes per day on average (15.7 and 12.4, respectively). Men initiated regular smoking earlier than women in each city (ranges 13.7–20.0 years vs 14.2–21.1 years, respectively). Exposure to secondhand tobacco smoke at workplace for more than 5 h per day was higher in Barquisimeto (28.7%), Buenos Aires (26.8%) and Santiago (21.5%). The highest prevalence of former smokers was found among men in Buenos Aires, Santiago and Lima (30.0%, 26.8% and 26.0% respectively).

Conclusions

Smoking prevalence was high in the seven CARMELA cities, although patterns of smoking varied among cities. A major health and economic burden is inevitable in urban Latin America unless effective comprehensive tobacco control measures recommended by the World Health Organisation Framework Convention on Tobacco Control are implemented.

Treating patients with respiratory disease who smoke

The high prevalence of cigarette smoking in patients with respiratory disease puts them at risk of developing clinically important drug interactions. Cigarette smoking reduces the therapeutic response to certain drugs such as theophyllines through the induction of hepatic cytochrome P450 isoenzymes. Smokers with asthma and patients with COPD have reduced sensitivity to corticosteroids, possibly due to non-eosinophilic airway inflammation, altered glucocorticoid receptor activity or reduced histone deacetylase activity. Although all smokers should be encouraged to stop smoking, there is limited information on the influence of smoking cessation on the therapeutic and anti-inflammatory effects of a number of the drugs used in the treatment of respiratory disease.

Environmental tobacco smoke exposure and child behaviors

RATIONALE

Emerging evidence suggests that exposure to environmental tobacco smoke (ETS) may be linked with behavior problems in childhood, but previous research has relied primarily on parent report of exposure, and results are inconclusive.

OBJECTIVES

To investigate the relationship between exposure to ETS and child behavior problems among children with asthma.

METHODS

The sample included 220 children who were enrolled in an asthma intervention trial and regularly exposed to ETS at home. Serum cotinine was used to measure exposure to tobacco smoke, and behavior problems were assessed by parent report on the Behavior Assessment System for Children. Covariates in adjusted analyses included: sex, age, race, asthma severity, asthma medication, maternal education, prenatal tobacco exposure, maternal depression, and Home Observation for Measurement of the Environment score.

RESULTS

Child behavior problems increased with increasing exposure to ETS. A stratified analysis of boys and girls separately indicated higher exposure among girls, but behavior problems were statistically significantly associated with exposure only in boys. Increasing behavior problems included externalizing behavior problems (beta= 2.23, p =.02) such as hyperactivity and aggression, internalizing behavior problems (beta= 2.19, p= .01) such as depression, and behavior symptoms (beta= 2.55, p= .01).

CONCLUSIONS

Among children with asthma, exposure to ETS is related to increased child behavior problems among boys.

Cigarette smoke extract induces thymic stromal lymphopoietin expression, leading to T(H)2-type immune responses and airway inflammation

BACKGROUND

Both active and passive smoking are considered to be risk factors for asthma development. However, the precise mechanisms involved remain elusive. Recently, thymic stromal lymphopoietin (TSLP) has been shown to play a key role in the development of T(H)2-type allergic inflammation in patients with asthma.

OBJECTIVE

The aim of this study was to investigate whether there was a causal relationship between cigarette smoke exposure and TSLP expression in the lung.

METHODS

We examined the effects of repeated intranasal exposure of cigarette smoke extract (CSE) on TSLP mRNA and protein expression in the mouse lung by means of real-time PCR, Western blotting, and immunohistochemistry. We also examined the effects of intranasal exposure of CSE plus ovalbumin (OVA) on T(H)2-type immune responses and lung pathology.

RESULTS

Repeated exposure of CSE induced TSLP mRNA and protein expression, which was inhibited by treatment with antioxidative N-acetylcysteine and by TNF-alpha receptor I deficiency. In addition, the intranasal exposure of CSE simultaneously with OVA induced OVA-specific T(H)2-type immune responses and airway inflammation, which were inhibited by the blockade of the TSLP activity.

CONCLUSION

CSE induced TSLP expression in the mouse lung in an oxidative stress-dependent and TNF-alpha receptor I-dependent manner, and when challenged simultaneously with an antigen, CSE promoted the development of airway inflammation in association with T(H)2-type immune responses.

Is there a disparity in the prevalence of asthma between American Indian and white adults?

BACKGROUND

Though racial disparities in asthma prevalence are well documented, little is known about the burden of asthma in American Indians compared to whites in the United States.

OBJECTIVES

To compare the prevalence of asthma among American Indian and white adults 18 years of age and older in Montana.

METHODS

We used Behavioral Risk Factor Surveillance System (BRFSS) data representative of the Montana population from 2001 to 2006.

RESULTS

Using multiple logistic regression analysis, American Indian race was not independently associated with increased asthma prevalence (OR 1.05, 95% CI 0.83-1.33). Obesity, lower household income and lower educational attainment, factors disproportionately affecting American Indians in Montana, were independently associated with increased asthma prevalence.

CONCLUSIONS

Regional and national surveillance is needed to comprehensively document asthma prevalence in American Indians and other underrepresented minorities in the United States.

Interpatient variability in rates of asthma progression: can genetics provide an answer?

Asthma is a heterogeneous disorder with a variable natural history. In children 3 patterns of the natural history of asthma have been described: early onset but transient, persistent, and later onset, with only the former leading to persistent asthma later in childhood. In adults a range of different asthma phenotypes differing in their environmental, inflammatory, and prognostic characteristics have also been described. These extend beyond allergic (extrinsic) and nonallergic (intrinsic) asthma to include persistent airflow obstruction and accelerated decrease in lung function over time. Asthma progression can be defined as the change in an individual's phenotype along a continuum ranging from nonasthmatic to asthmatic and subsequent development of severe chronic disease. It is clear that for prevention of asthma progression in patients, there is a need for both better understanding of the pathophysiology of asthma and identification of predictors of progression. Interpatient genetic variability has been shown to affect multiple facets of asthma progression, including increased susceptibility to atopy and subsequent asthma, progression to severe disease, and modification of the response to treatment. Thus genetic testing might provide a means for predicting the likely progression of an individual along the continuum, allowing targeting of preventative treatment. However, the prospect of the use of genetic information in clinical practice raises important social and ethical issues that will need to be addressed before genetic testing can be used to inform the preventative treatment of patients to prevent the development of progression of asthma in individuals.

Hypothesis--ultraviolet-B irradiance and vitamin D reduce the risk of viral infections and thus their sequelae, including autoimmune diseases and some cancers

Many viral infections reach clinical significance in winter, when it is cold, relative humidity is lowest and vitamin D production from solar ultraviolet-B irradiation is at its nadir. Several autoimmune diseases, such as multiple sclerosis, type 1 diabetes mellitus and asthma, are linked to viral infections. Vitamin D, through induction of cathelicidin, which effectively combats both bacterial and viral infections, may reduce the risk of several autoimmune diseases and cancers by reducing the development of viral infections. Some types of cancer are also linked to viral infections. The cancers with seemingly important risk from viral infections important in winter, based on correlations with increasing latitude in the United States, an index of wintertime solar ultraviolet-B dose and vitamin D, are bladder, prostate, testicular and thyroid cancer, Hodgkin's and non-Hodgkin's lymphoma, and, perhaps, gastric cancer. The evidence examined includes the role of viruses in the etiology of these diseases, the geographic and seasonal variation of these diseases, and the time of life when vitamin D is effective in reducing the risk of disease. In general, the evidence supports the hypothesis. However, further work is required to evaluate this hypothesis.

Recurrent exposure to nicotine differentiates human bronchial epithelial cells via epidermal growth factor receptor activation

Cigarette smoking is the major preventable cause of lung cancer in developed countries. Nicotine (3-(1-methyl-2-pyrrolidinyl)-pyridine) is one of the major alkaloids present in tobacco. Besides its addictive properties, its effects have been described in panoply of cell types. In fact, recent studies have shown that nicotine behaves as a tumor promoter in transformed epithelial cells. This research focuses on the effects of acute repetitive nicotine exposure on normal human bronchial epithelial cells (NHBE cells). Here we show that treatment of NHBE cells with recurrent doses of nicotine up to 500 muM triggered cell differentiation towards a neuronal-like phenotype: cells emitted filopodia and expressed neuronal markers such as neuronal cell adhesion molecule, neurofilament-M and the transcription factors neuronal N and Pax-3. We also demonstrate that nicotine treatment induced NF-kB translocation to the nucleus, phosphorylation of the epidermal growth factor receptor (EGFR), and accumulation of heparin binding-EGF in the extracellular medium. Moreover, addition of AG1478, an inhibitor of EGFR tyrosine phosphorylation, or cetuximab, a monoclonal antibody that precludes ligand binding to the same receptor, prevented cell differentiation by nicotine. Lastly, we show that differentiated cells increased their adhesion to the extracellular matrix and their protease activity. Given that several lung pathologies are strongly related to tobacco consumption, these results may help to better understand the damaging consequences of nicotine exposure.