Cigarette smoking and asthma symptom severity among adult asthmatics

The burden of severe asthma in sub-Saharan Africa: Findings from the African Severe Asthma Project

Background

Severe asthma is associated with high morbidity, mortality, and health care utilization, but its burden in Africa is unknown.

Objective

We sought to determine the burden (prevalence, mortality, and activity and work impairment) of severe asthma in 3 countries in East Africa: Uganda, Kenya, and Ethiopia.

Methods

Using the American Thoracic Society/European Respiratory Society case definition of severe asthma, we analyzed for the prevalence of severe asthma (requiring Global Initiative for Asthma [GINA] steps 4-5 asthma medications for the previous year to achieve control) and severe refractory asthma (remains uncontrolled despite treatment with GINA steps 4-5 asthma medications) in a cohort of 1086 asthma patients who had been in care for 12 months and had received all GINA-recommended medications. Asthma control was assessed by the asthma control questionnaire (ACQ).

Results

Overall, the prevalence of severe asthma and severe refractory asthma was 25.6% (95% confidence interval [CI], 23.1-28.3) and 4.6% (95% CI, 3.5-6.0), respectively. Patients with severe asthma were (nonsevere vs severe vs severe refractory) older (39, 42, 45 years, P = .011), had high skin prick test reactivity (67.1%, 76.0%, 76.0%, P = .004), had lower forced expiratory volume in 1 second percentage (81%, 61%, 55.5%, P < .001), had lower quality of life score (129, 127 vs 121, P < .001), and had higher activity impairment (10%, 30%, 50%, P < .001). Factors independently associated with severe asthma were hypertension comorbidity; adjusted odds ratio 2.21 (1.10-4.47), P = .027, high bronchial hyperresponsiveness questionnaire score; adjusted odds ratio 2.16 (1.01-4.61), P = .047 and higher ACQ score at baseline 2.80 (1.55-5.08), P = .001.

Conclusion

The prevalence of severe asthma in Africa is high and is associated with high morbidity and poor quality of life.

Evaluation of the prevalence of asthma and chronic obstructive pulmonary disease among opium users, and cigarette smokers and comparison with normal population in Kharameh: a cross-sectional study

BACKGROUND

Recent studies have suggested that opium use may increase mortality from pulmonary diseases. However, there are limited comprehensive studies regarding the prevalence of Asthma and Chronic Obstructive Pulmonary Disease (COPD) among tobacco and opium users has been published. We aimed to determine the prevalence of respiratory disease among tobacco and opium users.

METHODS

This cross-sectional study of tobacco and opium users and matched controls was conducted in the Kharameh Cohort, Fars, Iran. The prevalence of COPD and asthma, along with the participants demographical and spirometry data were examined.

RESULTS

The average age of participants was 57 ± 8 years. Never smokers had a significant higher BMI (26.6 vs. 24.8), FEV1 (91% vs. 82%) and FVC (96% vs. 88%) values compared to participants with a positive smoking status. There was a statistical difference in the prevalence of COPD, asthma, and asthma COPD overlap (ACO) based on the participants smoking status, with the highest prevalence among opium and cigarette smokers, followed by opium users alone. Based on multivariate analysis, higher age, lower BMI, lower education than under diploma, cigarette smoking and opium use were significantly correlated with higher COPD prevalence; while lower age, cigarette smoking and opium use were significantly correlated with higher asthma prevalence. Illiterate participants had a significantly higher prevalence of COPD (23.6%), asthma (22%), and ACO (7.9%) among the educational groups. Regarding the prevalence of asthma, the higher socio-economic group had the lowest prevalence.

CONCLUSIONS

Opium and tobacco users had a significantly higher prevalence of respiratory diseases, along with lower lung function tests based on spirometry evaluation.

Association between tobacco product use and asthma among US adults from the Population Assessment of Tobacco and Health (PATH) Study waves 2-4

BACKGROUND

Research on cigarettes and adult asthma offers mixed findings, perhaps due to overlap with chronic obstructive pulmonary disease (COPD) and inadequate adjustment for other smoke exposures. Associations between other tobacco products, including e-cigarettes, and asthma are also understudied.

RESEARCH QUESTION

Using Population Assessment of Tobacco and Health Study waves 2-4 (2014/2015-2016/2017) data, we assessed the relation between tobacco product use and asthma in persons unlikely to have COPD.

STUDY DESIGN AND METHODS

Prospective study of 10 267 adults aged 18-39 years without COPD diagnoses. Past-month tobacco use at wave 2 was modelled first as combustible versus non-combustible use and second as specific product categories (former, cigarettes, e-cigarettes, cigars, hookah, smokeless tobacco). Outcomes included lifetime asthma prevalence at wave 2, incidence (waves 3 and 4) and Asthma Control Test score (lower=worse). Multivariable regressions adjusted for predictors of asthma, including other smoke exposures: cigarette pack-years, secondhand smoke and marijuana use. Sensitivity analyses examined findings when persons >39 years and those with both COPD and asthma were added, and when smoke exposure adjustments were removed.

RESULTS

No product, including cigarettes and e-cigarettes, was associated with prevalence or incidence of asthma. Among people with asthma at wave 2, combustible tobacco (beta=-0.86, 95% CI (-1.32 to -0.39)) and cigarettes (beta=-1.14, 95% CI (-1.66 to -0.62)) were associated with worse asthma control. No tobacco product was associated with asthma control over time. In sensitivity analyses, tobacco use became associated with incident asthma as adults >39 years and those with asthma+COPD were added, and as adjustments for other smoke exposures were omitted.

INTERPRETATION

Although cigarette use was associated with worse asthma control, there were no longitudinal associations between combustible tobacco or e-cigarette use and new onset or worsening asthma in these preliminary analyses. Research on tobacco and asthma should exclude COPD and adjust for smoking history and other smoke exposures.

Asthma and Tobacco Smoking

Asthma is a prevalent chronic pulmonary condition with significant morbidity and mortality. Tobacco smoking is implicated in asthma pathophysiology, diagnosis, prognosis and treatment. Smokers display increased prevalence and incidence of asthma, but a causal association cannot be claimed using existing evidence. Second-hand smoking and passive exposure to tobacco in utero and early life have also been linked with asthma development. Currently, approximately one-fourth of asthma patients are smokers. Regular smokers with asthma might display accelerated lung function decline and non-reversible airflow limitation, making their distinction from chronic obstructive pulmonary disease patients challenging. Asthma patients who smoke typically have uncontrolled disease, as shown by increased symptoms, more exacerbations and impaired quality of life. On the other hand, smoking cessation improves lung function and asthma severity. Thus, asthma patients and their caregivers should be actively questioned about their smoking status at each medical encounter, and smoking cessation ought to be strongly encouraged both for patients with asthma and their close contacts. Smokers with asthma should be provided with comprehensive smoking cessation interventions on top of other anti-asthma medications.

Association of quality of life and disease control with cigarette smoking in patients with severe asthma

More information is needed on asthma control and health-related quality of life (HRQoL) in smokers with severe asthma. The main study objective was to characterize the association of HRQoL and disease control with cigarette smoking in individuals with severe asthma. A secondary objective was to analyze subject characteristics according to asthma onset: asthma that developed before smoking initiation versus asthma that developed after smoking initiation. This cross-sectional study included subjects with severe asthma aged 18-65 years. HRQoL was assessed using the Asthma Quality of Life Questionnaire (AQLQ) and asthma control was assessed using the Asthma Control Test (ACT) and Global Initiative for Asthma (GINA) criteria. Of the 87 patients studied, 58 (66.7%) were classified as asthmatics who had never smoked and 29 (33.3%) as asthmatics with smoking exposure. The proportion of subjects with uncontrolled asthma was higher in the asthma and smoking group (GINA criteria: P=0.032 and ACT criteria: P=0.003. There were no between-group differences in overall AQLQ score (P=0.475) or AQLQ domain scores (P>0.05). Fifty-eight subjects (66.7%) were nonsmokers, 20 (23%) had asthma onset before smoking, and 9 (10.3%) had asthma onset after smoking. Asthma onset before smoking was associated with uncontrolled asthma (P=0.013). In subjects with severe asthma, smoking was associated with a higher rate of uncontrolled disease but not with HRQoL scores.

Asthma phenotype: Clinical, physiological, and biochemical profiles of North Indian patients

Background and Objectives:

Asthma is a common, chronic and heterogeneous disease with various phenotypes. The clinical phenotypes has aided in revealing the genetic heterogeneity, provide education, life style advice and novel biological treatments. The few common factors associated with phenotypes are smoking, rhinitis and obesity. The present study was thus planned to analyse and correlate the clinical, physiological, biochemical and serological parameters of asthma and to study the phenotypic characteristics in different asthmatic.

Methods:

This was a prospective observational study of 120 patients with 30 each in BA-rhinitis, BA, BA-obesity and BA smoker phenotypes. All the enrolled patients were assessed by SGRQ, Mini-AQLQ, GINA with ACE, chest X ray, Spirometry, SPT against common aero-allergens, FENO, hsCRP, vitamin-D, IgE, and Interleukins (IL) including IL-5, IL-6, IL-8, IL-13, IL-17 and IL-33. The mentioned profiles of each phenotype correlated and characterized among different phenotypes.

Results:

The majority of patients 78(65%) were female with mean BMI of 24.07±4.73kg/m². Majority of the patient in BA and BA-rhinitis phenotype are in mild severity and young compared to majority in BA-obesity and BA-smoker are moderate to severe severity with older. (p<0.001) The SPT and FENO level were highest among BA-rhinitis phenotype with significant difference among phenotypes. (p<0.001) Similarly the most of inflammatory markers were significantly different in various phenotypes. The FEV1 showed correlation with most of parameters with statistically significant correlation with IL-5, IL-8 and FENO.

Conclusion:

The majority of parameters were significantly different among various phenotypes. We advise to phenotypic classification of asthma whenever possible for better management and quality of life.

Management Strategies to Reduce Exacerbations in non-T2 Asthma

There have been considerable advances in our understanding of asthmatic airway inflammation, resulting in a paradigm shift of classifying individuals on the basis of either the presence or the absence of type 2 (T2) inflammatory markers. Several novel monoclonal antibody therapies targeting T2 cytokines have demonstrated significant clinical effects including reductions in acute exacerbations and improvements in asthma-related quality of life and lung function for individuals with T2-high asthma. However, there have been fewer advancements in developing therapies for those without evidence of T2 airway inflammation (so-called non-T2 asthma). Here, we review the heterogeneity of molecular mechanisms responsible for initiation and regulation of non-T2 inflammation and discuss both current and potential future therapeutic options for individuals with non-T2 asthma.

Exposure to household air pollution over 10 years is related to asthma and lung function decline

INTRODUCTION

We investigated if long-term household air pollution (HAP) is associated with asthma and lung function decline in middle-aged adults, and whether these associations were modified by glutathione S-transferase (GST) gene variants, ventilation and atopy.

MATERIALS AND METHODS

Prospective data on HAP (heating, cooking, mould and smoking) and asthma were collected in the Tasmanian Longitudinal Health Study (TAHS) at mean ages 43 and 53 years (n=3314). Subsamples had data on lung function (n=897) and GST gene polymorphisms (n=928). Latent class analysis was used to characterise longitudinal patterns of exposure. Regression models assessed associations and interactions.

RESULTS

We identified seven longitudinal HAP profiles. Of these, three were associated with persistent asthma, greater lung function decline and % reversibility by age 53 years compared with the "Least exposed" reference profile for those who used reverse-cycle air conditioning, electric cooking and no smoking. The "All gas" (OR 2.64, 95% CI 1.22-5.70), "Wood heating/smoking" (OR 2.71, 95% CI 1.21-6.05) and "Wood heating/gas cooking" (OR 2.60, 95% CI 1.11-6.11) profiles were associated with persistent asthma, as well as greater lung function decline and % reversibility. Participants with the GSTP1 Ile/Ile genotype were at a higher risk of asthma or greater lung function decline when exposed compared with other genotypes. Exhaust fan use and opening windows frequently may reduce the adverse effects of HAP produced by combustion heating and cooking on current asthma, presumably through increasing ventilation.

CONCLUSIONS

Exposures to wood heating, gas cooking and heating, and tobacco smoke over 10 years increased the risks of persistent asthma, lung function decline and % reversibility, with evidence of interaction by GST genes and ventilation.

[Asthma 2020 Nursing Consensus Document]

Asthma is a chronic respiratory disease which presents with a risk of exacerbations. Good patient management and continuous monitoring are crucial for good disease control, and pharmacological and non-pharmacological interventions are essential for proper treatment. Nurses specialised in asthma can contribute to the correct management of asthmatic patients. They play a key role in diagnostic tests, administration of medication, and patient follow-up and education. This consensus arose from the need to address an aspect of asthma management that does not appear in the specific recommendations of current guidelines. This document highlights and updates the role of specialized nurses in the care and management of asthma patients, offering conclusions and practical recommendations with the aim of improving their contribution to the treatment of this disease. Proposed recommendations appear as the result of a nominal consensus which was developed during 2019, and validated at the beginning of 2020.

Associations between historical residential redlining and current age-adjusted rates of emergency department visits due to asthma across eight cities in California: an ecological study

BACKGROUND

Asthma disproportionately affects communities of colour in the USA, but the underlying factors for this remain poorly understood. In this study, we assess the role of historical redlining as outlined in security maps created by the Home Owners' Loan Corporation (HOLC), the discriminatory practice of categorising neighbourhoods on the basis of perceived mortgage investment risk, on the burden of asthma in these neighbourhoods.

METHODS

We did an ecological study of HOLC risk grades and asthma exacerbations in California using the security maps available for the following eight cities: Fresno, Los Angeles, Oakland, Sacramento, San Diego, San Jose, San Francisco, and Stockton. Each census tract was categorised into one of four risk levels (A, B, C, or D) on the basis of the location of population-weighted centroids on security maps, with the worst risk level (D) indicating historical redlining. We obtained census tract-level rates of emergency department visits due to asthma from CalEnviroScreen 3.0. We assessed the relationship between risk grade and log-transformed asthma visit rates between 2011 and 2013 using ordinary least squares regression. We included potential confounding variables from the 2010 Census and CalEnviroScreen 3.0: diesel exhaust particle emissions, PM_2·5, and percent of the population living below 2 times the federal poverty level. We also built random intercept and slope models to assess city-level variation in the relationship between redlining and asthma.

FINDINGS

In the 1431 census tracts assessed (64 [4·5%] grade A, 241 [16·8%] grade B, 719 [50·2%] grade C, and 407 [28·4%] grade D), the proportion of the population that was non-Hispanic black and Hispanic, the percentage of the population living in poverty, and diesel exhaust particle emissions all significantly increased as security map risk grade worsened (p<0·0001). The median age-adjusted rates of emergency department visits due to asthma were 2·4 times higher in census tracts that were previously redlined (median 63·5 [IQR 34·3] visits per 10 000 residents per year [2011-13]) than in tracts at the lowest risk level (26·5 [18·4]). In adjusted models, redlined census tracts were associated with a relative risk of 1·39 (95% CI 1·21-1·57) in rates of emergency department visits due to asthma compared with that of lowest-risk census tracts.

INTERPRETATION

Historically redlined census tracts have significantly higher rates of emergency department visits due to asthma, suggesting that this discriminatory practice might be contributing to racial and ethnic asthma health disparities.

FUNDING

National Heart Lung Blood Institute.

Asthma

This review provides an evidence-based guide for the diagnosis, evaluation, and treatment of patients with asthma. It addresses typical questions that arise in the clinic-based care of patients with asthma and provides a basic and comprehensive resource for asthma care.

Heterogeneity and the origins of asthma

OBJECTIVE

To examine the roots of asthma across different ages, including atopy, the role of the microbiome and viral infections, and comorbidities and confounders, such as obesity, aspirin-exacerbated respiratory disease, neutrophilic asthma, cigarette smoking, and the possibility of an asthma-chronic obstructive pulmonary disease overlap syndrome.

DATA SOURCES

Data were taken from various scientific search engines, including PubMed and Science Direct databases.

STUDY SELECTIONS

Articles that reviewed information on the origins of asthma in persons of all ages, including different phenotypes and genotypes of asthma, were used.

RESULTS

Asthma is a common and complex disease whose origins are likely a combination of both genetic predisposition and environmental exposures. Factors such as the microbiome, other atopic disease, viral infections in young children, and other diagnoses, such as obesity or aspirin-exacerbated respiratory disease, are important to consider when creating a treatment plan for patients.

CONCLUSION

Asthma is a disease that is often diagnosed in childhood but can present at any age. There is debate in the field as to whether asthma is one disease or several different diseases that include airway inflammation as a key finding. There are risk factors for disease in the environment and through comorbidities that likely play significant roles in the origins of asthma, the development of symptoms, and the response to treatment. These factors are even more important as we look toward the future with the goal of personalized medicine.

Differences in airway structural changes assessed by 3-dimensional computed tomography in asthma and asthma-chronic obstructive pulmonary disease overlap

BACKGROUND

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is a clinical phenotype sharing features of asthma and COPD. Multidetector row computed tomography (MDCT) can be used to evaluate the airway structure; however, differences between asthma and ACO seen on MDCT are poorly understood.

OBJECTIVE

To investigate the difference in airway structural between asthma and ACO, using MDCT in patients with clinical asthma.

METHODS

Sixty-four patients with asthma were allocated to an asthma group (never smokers and ex-smokers with a smoking history of < 10 pack-years) or an ACO group (patients with a ≥10-pack-year smoking history and forced expiratory volume in 1 second [FEV₁]/forced vital capacity [FVC] < 0.7). The asthma group was further divided into patients with airflow limitation (AL; FEV₁/FVC < 0.7) and those without AL. Wall thickness (WT) and airway inner luminal area in the third-generation to fifth-generation bronchi were evaluated using MDCT in both study groups and in 29 healthy controls.

RESULTS

Forty-three patients were included in the asthma group (20 with AL, 23 without AL) and 16 in the ACO group. Patients with asthma and ACO had significantly greater WT than the healthy controls. WT in the third-generation bronchi was significantly greater in the ACO group than in the asthma group. The ACO group and the asthma with AL group were matched for age, disease duration, and FEV₁/FVC. The WT in the third-generation bronchi was still greater in the ACO group than in the asthma with AL group.

CONCLUSION

Patients with ACO have a thicker airway wall than those with asthma, suggesting that airway remodeling is more prominent in ACO than in asthma. UMIN Clinical Trials Registry (UMIN-CTR) system (http://www.umin.ac.jp/ctr/UMIN000028913).

Modelling the asthma phenotype: impact of cigarette smoke exposure

Background

Asthmatics that are exposed to inhaled pollutants such as cigarette smoke (CS) have increased symptom severity. Approximately 25% of adult asthmatics are thought to be active smokers and many sufferers, especially in the third world, are exposed to high levels of inhaled pollutants. The mechanism by which CS or other airborne pollutants alter the disease phenotype and the effectiveness of treatment in asthma is not known. The aim of this study was to determine the impact of CS exposure on the phenotype and treatment sensitivity of rodent models of allergic asthma.

Methods

Models of allergic asthma were configured that mimicked aspects of the asthma phenotype and the effect of CS exposure investigated. In some experiments, treatment with gold standard asthma therapies was investigated and end-points such as airway cellular burden, late asthmatic response (LAR) and airway hyper-Reactivity (AHR) assessed.

Results

CS co-exposure caused an increase in the LAR but interestingly attenuated the AHR. The effectiveness of LABA, LAMA and glucocorticoid treatment on LAR appeared to be retained in the CS-exposed model system. The eosinophilia or lymphocyte burden was not altered by CS co-exposure, nor did CS appear to alter the effectiveness of glucocorticoid treatment. Steroids, however failed to reduce the neutrophilic inflammation in sensitized mice exposed to CS.

Conclusions

These model data have certain parallels with clinical findings in asthmatics, where CS exposure did not impact the anti-inflammatory efficacy of steroids but attenuated AHR and enhanced symptoms such as the bronchospasm associated with the LAR. These model systems may be utilised to investigate how CS and other airborne pollutants impact the asthma phenotype; providing the opportunity to identify novel targets.

Increased Risk of Exacerbation in Asthma Predominant Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome

Background

Obstructive airway disease patients with increased variability of airflow and incompletely reversible airflow obstruction are often categorized as having asthma–chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS). ACOS is heterogeneous with two sub-phenotypes: asthma-ACOS and COPD-ACOS. The objective of this study was to determine the difference in risk of exacerbation between the two sub-phenotypes of ACOS.

Methods

A total of 223 patients exhibiting incompletely reversible airflow obstruction with increased variability (spirometrically defined ACOS) were enrolled. These patients were divided into asthma-ACOS and COPD-ACOS according to their physician's diagnosis and smoking history of 10 pack-years. Within-group comparisons were made for asthma-ACOS versus COPD-ACOS and light smokers versus heavy smokers.

Results

Compared to patients with COPD-ACOS, patients with asthma-ACOS experienced exacerbation more often despite their younger age, history of light smoking, and better lung function. While the light-smoking group showed better lung function, they made unscheduled outpatient clinic visits more frequently. On multivariate analysis, asthma-ACOS and poor inhaler compliance were significantly associated with more than two unscheduled clinic visits during the previous year.

Conclusion

Spirometrically defined ACOS includes heterogeneous subgroups with different clinical features. Phenotyping of ACOS by physician's diagnosis could be significant in predicting future risk of exacerbation.

The role of anxiety sensitivity-physical concerns in terms of quit day withdrawal symptoms and cravings: A pilot test among smokers with asthma

OBJECTIVE

The aim of the current study was to conduct secondary analyses of data collected from a study examining a self-guided quit attempt of smokers with and without asthma in order to examine the unique predictive ability of precessation (i.e., baseline) anxiety sensitivity physical concerns in terms of quit day withdrawal symptoms and cravings among abstinent smokers with asthma.

METHODS

Participants were 24 regular cigarette smokers with asthma (50% female, M_age = 37.63 years, SD = 12.20) who participated in a self-guided-quit attempt and were able to maintain abstinence on their quit day.

RESULTS

After controlling for the effects of the cognitive and social concerns domains of anxiety sensitivity, anxiety sensitivity-physical concerns significantly predicted greater quit day withdrawal symptoms (20.8% unique variance) and urges to smoke (38.0% unique variance).

CONCLUSIONS

These findings suggest that smokers with asthma who fear anxiety-related sensations due to their feared physical consequences are more likely to experience intense withdrawal symptoms and desire to smoke at the beginning of a quit attempt. Clinically, smokers with higher levels of anxiety sensitivity physical concerns may benefit from smoking cessation interventions that specifically target anxiety sensitivity as well as prolonged use of nicotine replacement therapies to target withdrawal symptoms and cravings.

Traditional Therapies for Severe Asthma

Severe asthma is a complex and heterogeneous disease. The European Respiratory Society and American Thoracic Society guidelines define severe asthma for patients 6 years or older as "asthma which requires treatment with high-dose inhaled corticosteroids…plus a second controller or systemic corticosteroids to prevent it from becoming 'uncontrolled' or which remains 'uncontrolled' despite this therapy." This article reviews available traditional therapies, data behind their uses in severe asthma, and varying recommendations. As various asthma endotypes and phenotypes are better understood and characterized, targeted therapies should help improve disease outcomes, efficacy, and cost-effectiveness.

Respiratory problems and anxiety sensitivity in smoking lapse among treatment seeking smokers

PURPOSE

The current study examined whether the interaction of lower respiratory symptoms and anxiety sensitivity is related to smoking lapse in the context of smoking cessation.

METHOD

Participants were adult daily smokers (N=60) exposed to the World Trade Center (WTC) disaster who were in a smoking cessation treatment program (75.0% male, 50.6years old [SD=9.2], and current smoking rate was 17.6 cigarettes per day (SD=10.6).

RESULTS

Results indicated that the interaction between lower respiratory symptoms and anxiety sensitivity was a significant predictor of greater risk for lapse (i.e., lower survival time; B=0.005, OR=1.01, p=0.039). Follow-up analysis showed that greater respiratory symptoms were a significant predictor of lapse risk among those with high (B=0.116, OR=1.12, p=0.025), but not those with low (B=-0.048, OR=0.95, p=0.322), levels of anxiety sensitivity.

DISCUSSION

The findings from the current study suggest that smokers with greater respiratory symptoms and higher levels of anxiety sensitivity may be associated with early lapse to smoking following smoking cessation treatment. Future work has the potential to inform the development of tailored cessation interventions for smokers who experience varying levels of lower respiratory symptoms and anxiety sensitivity.

Strategies to alter the natural history of childhood asthma

PURPOSE OF REVIEW

Asthma exhibits significant heterogeneity in occurrence and severity over the lifespan. Our goal is to discuss recent evidence regarding determinants of the natural history of asthma during childhood, and review the rationale behind and status of major efforts to alter its course.

RECENT FINDINGS

Variations in microbial exposures are associated with risk of allergic disease, and the use of bacterial lysates may be a promising preventive strategy. Exposure to air pollution appears to be particularly damaging in prenatal and early life, and interventions to reduce pollution are feasible and result in clinical benefit. E-cigarette use may have a role in harm reduction for conventional cigarette smokers with asthma, but has undefined short-term and long-term effects that must be clarified. Vitamin D insufficiency over the first several years of life is associated with risk of asthma, and vitamin D supplementation reduces the risk of severe exacerbations.

SUMMARY

The identification of risk factors for asthma occurrence, persistence and severity will continue to guide efforts to alter the natural history of the disease. We have reviewed several promising strategies that are currently under investigation. Vitamin D supplementation and air pollution reduction have been shown to be effective strategies and warrant increased investigation and implementation.

Cellular and noncellular bloodborne biomarkers in asthma

OBJECTIVE

To provide an overview of studied cellular and noncellular blood-derived asthma biomarkers.

DATA SOURCES

PubMed literature review.

STUDY SELECTIONS

Articles discussing cellular and noncellular bloodborne asthma biomarkers.

RESULTS

Discussed asthma biomarkers include peripheral blood cell counts of T cells, fibrocytes, or granulocytes, as well as levels of cytokines, periostin, IgE, and lipid mediators with or without stimulation. Moreover, this article summarizes the association of various blood biomarkers with the type of airway inflammation, presence of atopy, and dominance of specific T-cell subsets and associated pathways in asthma. Furthermore, biomarkers are here listed according to their proposed clinical use, such as diagnosis, disease phenotyping, classification of severity, assessment of disease control, and monitoring of and predicting treatment response.

CONCLUSION

Further research on asthma biomarkers may improve asthma endotyping and ultimately lead to personalized treatment.

Validity of the Asthma Control Test Questionnaire Among Smoking Asthmatics

BACKGROUND

Smoking asthmatics respond worse to existing asthma therapies and have more asthma symptoms and exacerbations.

OBJECTIVE

We evaluated the Asthma Control Test (ACT) for assessing asthma control among smokers.

METHODS

Adults with asthma who smoked were enrolled and followed for 6 weeks. The statistical properties, validity, and responsiveness of the ACT were evaluated. Physician global assessment (GS) of asthma was the "gold standard."

RESULTS

A total of 151 participants were enrolled: 52% female and 48% male. The median (interquartile ranges) was 35 (27, 43) years for age, 11 (7, 18) for pack-years, and 16 (13, 20) for the ACT score. Participants self-identified as African American (49%), non-Hispanic whites (38%), and Hispanic whites (11%). Participants were classified as well controlled (24%), not well controlled (42%), or very poorly controlled (34%) at enrollment. Cronbach's alpha (95% confidence interval [CI]) for the ACT at enrollment was 0.81 (0.76, 0.85). The intraclass correlation coefficient (95% CI) for agreement of scores at enrollment and 6 weeks was 0.68 (0.57, 0.78) in participant with stable asthma (n = 93). ACT scores were associated with GS (P < .001). Area under the receiver operating characteristic (ROC) curve (95% CI) for an ACT cutoff score of ≤19 (not well controlled) was 0.76 (0.67, 0.84). The ACT score with the maximum area under the ROC curve was 18.6.

CONCLUSIONS

The ACT questionnaire was reliable and discriminated between levels of asthma control in smoking asthmatics with similar sensitivity and specificity as nonsmoking asthmatics, which confirms its value as a tool for the management of asthma in this prevalent but understudied subgroup of subjects.

Cigarette smoking increases bronchial mucosal IL-17A expression in asthmatics, which acts in concert with environmental aeroallergens to engender neutrophilic inflammation

BACKGROUND

Mild asthmatics who smoke cigarettes may develop unstable disease and neutrophilic infiltration of the airways, features more usually associated with severe asthmatic disease. The mechanisms giving rise to this response remain unclear.

OBJECTIVE

To address the hypothesis that smoking increases bronchial mucosal production of IL-17A which acts on bronchial epithelial cells directly and in concert with other environmental stimuli to induce the production of IL-6 and neutrophil chemotaxins.

METHODS

IL-17A, IL-8, IL-6, neutrophils and eosinophils were detected and quantified by immunohistochemistry in endobronchial biopsy sections from smoking and non-smoking asthmatics. Human tracheal epithelial cells (HTEpC) were cultured with IL-17A in the presence/absence of cigarette smoke extract (CSE) and aeroallergens lacking intrinsic protease activity, and IL-6 and IL-8 production measured in vitro.

RESULTS

Expression of IL-17A, IL-6 and IL-8 and neutrophil numbers was significantly elevated in the bronchial mucosa of the asthmatic smokers compared to the non-smokers. Expression of IL-17A correlated with that of IL-8 and neutrophil numbers. In the smoking asthmatics, eosinophil numbers also correlated with expression of IL-8 and IL-17A. Exposure of HTEpC cells to both CSE and IL-17A increased expression of IL-6 and IL-8 in a concentration-dependent and synergistic manner. Co-stimulation with CSE, IL-17A and aeroallergens further increased IL-6 and IL-8 production synergistically.

CONCLUSIONS

The data support the hypothesis that asthmatic smokers develop neutrophilic inflammation of the airways propagated at least partly by smoke-induced production of IL-17A which together with smoke and other environmental stimuli acts on airways epithelial cells to induce neutrophil chemotaxins.

Effect of waterpipe tobacco smoking on airway inflammation in murine model of asthma

OBJECTIVE

There has been an increase in the popularity of waterpipe tobacco smoking (WTS) worldwide, especially in the younger population, including asthma patients. In this study, we investigated the effects of waterpipe smoking on airway inflammation, cytokine levels and oxidative stress markers in an antigen-driven murine model of asthma.

MATERIALS AND METHODS

Balb/c mice were divided into four groups; (1) control (received fresh air, ovalbumin sensitization and saline challenge), (2) WTS (received WTS, ovalbumin sensitization and saline challenge), (3) Ova S/C (received fresh air, ovalbumin sensitization and ovalbumin challenge) and (4) simultaneous WTS and Ova S/C (received WTS, ovalbumin sensitization and ovalbumin challenge). Airway inflammatory cells were evaluated in the broncho-alveolar lavage fluid. Cytokines [interleukin (IL)-13, 10 and 18] and oxidative stress markers [superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx)] were evaluated in the lung homogenates.

RESULTS

Chronic exposure to WTS significantly increased the number of airway inflammatory cells in mice, specifically: eosinophils, neutrophils, macrophages and lymphocytes. The level of IL-13 in the lungs was increased and the level of IL-10 was reduced (p < 0.05) by WTS. Chronic WTS potentiated the increase in inflammatory cells induced by Ova S/C (p < 0.05). The level of IL-13 in the lungs was increased by simultaneous WTS and Ova S/C (p < 0.05) while, levels of IL-10, IL-18, SOD, catalase and GPx in the lungs were not affected.

CONCLUSIONS

Chronic WTS exposure induced airway inflammation in control mice and enhanced airway inflammation in murine model of asthma.

Evaluation of smokers with and without asthma in terms of smoking cessation outcome, nicotine withdrawal symptoms, and craving: Findings from a self-guided quit attempt

INTRODUCTION

The aim of the current study was to evaluate smoking cessation outcome, nicotine withdrawal symptoms, and craving between smokers with (n=47; 46.8% male, Mage=40.0years, SD=11.7) and without (n=45; 51.1% male, Mage=37.5years, SD=11.1) asthma during a self-guided quit attempt.

METHODS

After completing a baseline assessment visit, participants attended study sessions on their scheduled quit day as well as follow-up visits (3days, 7days, 14days, and 28days) after their quit day.

RESULTS

Smokers with and without asthma did not differ in abstinence rates, smoking lapse, and rate of change in urge to smoke to reduce negative affect. However, smokers with asthma demonstrated a slower rate of decline in nicotine withdrawal symptoms and craving over time.

CONCLUSIONS

These findings suggest that smokers with asthma may benefit from specialized smoking cessation treatments to address prolonged withdrawal symptoms and craving.

Use of biologics to treat acute exacerbations and manage disease in asthma, COPD and IPF

A common feature of chronic respiratory disease is the progressive decline in lung function. The decline can be indolent, or it can be accelerated by acute exacerbations, whereby the patient experiences a pronounced worsening of disease symptoms. Moreover, acute exacerbations may also be a marker of insufficient disease management. The underlying cause of an acute exacerbation can be due to insults such as pathogens or environmental pollutants, or the cause can be unknown. For each acute exacerbation, the patient may require medical intervention such as rescue medication, or in more severe cases, hospitalization and ventilation and have an increased risk of death. Biologics, such as monoclonal antibodies, are being developed for chronic respiratory diseases including asthma, COPD and IPF. This therapeutic approach is particularly well suited for chronic use based on the route and frequency of delivery and importantly, the potential for disease modification. In recent clinical trials, the frequency of acute exacerbation has often been included as an endpoint, to help determine whether the investigational agent is impacting disease. Therefore the significance of acute exacerbations in driving disease, and their potential as a marker of disease activity and progression, has recently received much attention. There is also now a need to standardize the definition of an acute exacerbation in specific disease settings, particularly as this endpoint is increasingly used in clinical trials to also assess therapeutic efficacy. Moreover, specifically targeting exacerbations may offer a new therapeutic approach for several chronic respiratory diseases.

Immediate effects of cigar smoking on respiratory mechanics and exhaled biomarkers; differences between young smokers with mild asthma and otherwise healthy young smokers

Background

We aimed to investigate the immediate respiratory effects of cigar smoking(CS), among young smokers with and without mild asthma.

Materials and methods

Forty-seven young smokers (18–31years old, 29 males, average pack-years = 3.6 ± 2.8) were enrolled. Twenty-two were mild asthmatics(MA-subgroup) and the remaining 25 were otherwise healthy smokers(HS-subgroup). Exhaled carbon monoxide(eCO), multi-frequency respiratory system impedance(Z), resistance(R), reactance(X), frequency-dependence of resistance(fdr = R5Hz - R20Hz), resonant frequency(f_res), reactance area(AX) and exhaled nitric oxide(FENO) were measured at the aforementioned sequence, before and immediately after 30 min of CS, or equal session in the smoking area while using a sham cigar(control group). Chi-square, student’s t-tests, mixed linear models and Pearson correlation tests were used for the statistical analysis; level of significance was defined as p < 0.05.

Results

Immediately after CS, Z5Hz, R5Hz, R10Hz, R20Hz and eCO increased significantly in both subgroups(MA and HS). A greater increase was found for R20 in HS-subgroup. Fdr, f_res and AX increased in MA, while decreased in HS. On the contrary, X10 decreased in MA and increased in HS, while X20 showed a greater decrease in MA. Changes in fdr, f_res and AX were significantly correlated in both subgroups. No significant FENO alterations were detected in both subgroups.

Conclusion

CS has immediate effects on pulmonary function. Mild asthma predisposes to higher increase of peripheral resistance(increased fdr). In otherwise healthy smokers, central resistance(R20Hz) is more affected. FENO levels are not significantly affected by CS.

Randomized trial of allergen-induced asthmatic response in smokers and non-smokers: effects of inhaled corticosteroids

BACKGROUND

It is thought that asthmatics who smoke cigarettes respond less well to inhaled corticosteroid (ICS) therapy than asthmatics who do not smoke.

OBJECTIVE

To evaluate the effects of smoking on allergen-induced airway responses in asthmatics treated with ICS.

METHODS

Randomized, double-blind, crossover study evaluating twice daily fluticasone propionate (FP) 100 μg, FP 500 μg and placebo, for 7 days, on allergen-induced asthmatic responses in 18 non-smoking and 17 smoking atopic asthmatics (NCT01400906). At 1 h post-morning dose on Day 6, forced expiratory volume in 1 sec (FEV1 ) was measured up to 10 h post-challenge. Exhaled nitric oxide (eNO), induced sputum cell counts, and responsiveness to methacholine were assessed the following day.

RESULTS

The late asthmatic response (LAR) was suppressed by FP in smokers and non-smokers; with placebo, the LAR was also attenuated in smokers versus non-smokers (adjusted mean minimum change in FEV1 (L) over 4-10 h [95% CI] in non-smokers: placebo -1.01 [1.31, 0.70], FP 100 μg -0.38 [0.54, 0.22], FP 500 μg -0.35 [0.54-0.22]; and in smokers: placebo -0.63 [0.84, 0.43]; FP 100 μg -0.44 [0.65, 0.23]; FP 500 μg -0.46 [0.59-0.32]). The Early AR was suppressed by FP treatment in non-smokers, but was not impacted in smokers. The reduction in methacholine hyperresponsiveness after FP was greater in non-smokers (1.5- and twofold doubling dose difference from placebo after FP 100 μg and FP 500 μg) than smokers (1.0 and 1.3 difference, respectively). Allergen-induced increases in eNO and sputum eosinophils were lower in smokers than non-smokers and were suppressed in both groups by FP.

CONCLUSION AND CLINICAL RELEVANCE

Allergen-induced LARs were of a similar amplitude in both smoking and non-smoking atopic asthmatics at the end of ICS treatment, but attenuation of the LAR in smokers was only partly associated with ICS treatment. The marked attenuation of the LAR observed in smokers in the absence of ICS treatment is a novel observation.

Asthma quality of life in Saudi Arabia: Gender differences

OBJECTIVES

To explore potential gender differences in the factors associated with asthma-specific quality of life (AQL).

METHODS

A cross-sectional study of consecutive series of adult patients attending primary care centers at three major hospitals in Riyadh, Saudi Arabia, was performed. AQL was measured using a standardized version of the AQL questionnaire (min = 1, max = 7), with higher scores indicating a better AQL. Multiple linear regression analysis was performed.

RESULTS

The mean AQL was 4.3 (standard deviation [SD] = 1.5) for males and 4.0 (SD = 1.3) for females (p = 0.113). With each unit increase in asthma control, the AQL improved by 0.19 points (95% confidence interval [CI] = 0.14-0.23) in men and by 0.21 points (95% CI = 0.16-0.25) in women. Daily tobacco smoking was associated with a 0.72 point (95% CI = 0.14-1.30) decrease in the AQL among males. Women who had a household member who smoked inside the house had a significantly lower AQL (B = -0.59, 95% CI = -1.0 - -0.19). A monthly household income of 25,000 Saudi Riyals or more was associated with a better AQL among men (B = 0.51, 95% CI = 0.01-1.01), whereas being employed exhibited a protective effect in women (B = 0.48, 95% CI = 0.11-0.84). Higher levels of perceived asthma severity were associated with better AQL in women (B = 0.82, 95% CI = 0.36-1.28).

CONCLUSIONS

Our findings revealed gender-specific differences in the correlates of AQL in Saudi Arabia, particularly in tobacco exposure, socio-economic factors and perceived asthma severity.

Corticosteroid insensitivity in smokers with asthma : clinical evidence, mechanisms, and management

Corticosteroids are the most effective treatment for asthma, but the therapeutic response varies considerably between individuals. Several clinical studies have found that smokers with asthma are insensitive to the beneficial effects of short- to medium-term inhaled corticosteroid treatment compared with non-smokers with asthma. It is estimated that 25% of adults in most industrialized countries smoke cigarettes, and similar surveys amongst asthmatic individuals suggest that the prevalence of smoking in this grouping mirrors that found in the general population. Therefore, cigarette smoking is probably the most common cause of corticosteroid insensitivity in asthma. Cigarette smoking and asthma are also associated with poor symptom control and an accelerated rate of decline in lung function. The mechanism of corticosteroid insensitivity in smokers with asthma is currently unexplained but could be due to alterations in airway inflammatory cell phenotypes, changes in glucocorticoid receptor alpha/beta ratio, and/or reduced histone deacetylase activity. Smoking cessation should be encouraged in all smokers with asthma. Short-term benefits include improvements in lung function and asthma control. However, the numbers of sustained quitters is disappointingly small. Additional or alternative drugs need to be identified to treat those individuals who are unable to stop smoking or who have persistent symptoms following smoking cessation.

Differences in panic psychopathology between smokers with and without asthma

Cigarette smoking is more common among individuals with asthma compared to those without, resulting in increased risk of morbidity and mortality. However, there has been little exploration of psychological factors that differ between smokers with and without asthma. Thus, the aim of the current study was to examine differences between smokers with and without asthma in terms of anxiety sensitivity, panic symptoms, lifetime history of panic attacks, and lifetime history of panic disorder. Participants were 115 smokers with asthma (55.3% male, M_age = 38.4 years, SD = 11.9) and 120 smokers without asthma (70.6% male, M_age = 37.0 years, SD = 12.8) who were administered a structured diagnostic interview and completed self-report measures. As hypothesized, after controlling for the effects of cigarettes per day, gender, race, and education, smokers with asthma reported higher levels of anxiety sensitivity and panic symptoms and were at an increased risk for having a lifetime history of panic attacks (OR = 3.01) and panic disorder (OR = 2.96) compared to smokers without asthma. Further, group differences in anxiety sensitivity and panic symptoms remained even after removing participants with a lifetime history of panic attacks or panic disorder. These findings suggest that smokers with asthma are a particularly 'at-risk' population for panic psychopathology and likely in need of specialized smoking-related prevention and intervention efforts.

An Examination of the Indirect Effect of Anxiety Sensitivity in terms of Asthma and Smoking Cessation Processes

INTRODUCTION

Despite the increased rates of smoking and poor cessation outcomes among individuals with asthma relative to those without, little scholarly attention has examined mechanisms linking asthma to smoking cessation processes. The current study sought to examine the indirect effect of anxiety sensitivity in terms of asthma and smoking cessation processes (i.e., duration of longest quit attempt, motivation to quit smoking, smoking dependence motives).

METHODS

Participants were 90 regular daily smokers: 43 with asthma (51.2% male, M(age) = 38.0 years, SD = 12.5) and 47 without asthma (46.8% male, M(age) = 35.4 years, SD = 11.2) who were participating in a larger smoking cessation study. Data from the baseline (pre-quit attempt) assessment session were used.

RESULTS

After accounting for the effects of gender, race, daily smoking rate, and negative affectivity, asthma status was indirectly related to motives for smoking related to nicotine dependence and motivation to quit smoking through anxiety sensitivity. There was no significant indirect effect for duration of longest quit attempt.

CONCLUSIONS

These findings suggest that smokers with asthma may be particularly fearful of physiological arousal, which in turn, may account for greater motivation to quit smoking, but also stronger dependence motives for smoking.

Activated p38 MAPK in Peripheral Blood Monocytes of Steroid Resistant Asthmatics

Steroid resistance is a significant problem in management of chronic inflammatory diseases, including asthma. Accessible biomarkers are needed to identify steroid resistant patients to optimize their treatment. This study examined corticosteroid resistance in severe asthma. 24 asthmatics with forced expiratory volume in one second of less then 80% predicted were classified as steroid resistant or steroid sensitive based on changes in their lung function following a week of treatment with oral prednisone. Heparinised blood was collected from patients prior to oral prednisone administration. Phosphorylated mitogen activated kinases (MAPK) (extracellular regulated kinase (ERK), p38 and jun kinase (JNK)) were analyzed in whole blood samples using flow cytometry. Activation of phospho-p38 MAPK and phospho-mitogen- and stress-activated protein kinase 1 (MSK1) in asthmatics’ peripheral blood mononuclear cells (PBMC) were confirmed by Western blot. Dexamethasone suppression of the LPS-induced IL-8 mRNA production by steroid resistant asthmatics PBMC in the presence of p38 and ERK inhibitors was evaluated by real time PCR. Flow cytometry analysis identified significantly stronger p38 phosphorylation in CD14⁺ monocytes from steroid resistant than steroid sensitive asthmatics (p = 0.014), whereas no difference was found in phosphorylation of ERK or JNK in CD14⁺ cells from these two groups of asthmatics. No difference in phosphorylated p38, ERK, JNK was detected in CD4⁺, CD8⁺ T cells, B cells and NK cells from steroid resistant vs. steroid sensitive asthmatics. P38 MAPK pathway activation was confirmed by Western blot, as significantly higher phospho-p38 and phospho-MSK1 levels were detected in the PBMC lysates from steroid resistant asthmatics. P38 inhibitor significantly enhanced DEX suppression of LPS-induced IL-8 mRNA by PBMC of steroid resistant asthmatics. This is the first report demonstrating selective p38 MAPK pathway activation in blood monocytes of steroid resistant asthmatics, suggesting that p38 and MSK1 phosphorylation can serve as blood biomarkers of steroid resistance.

Epithelial function and dysfunction in asthma

Asthma was previously defined as an allergic Th2-mediated inflammatory immune disorder. Recently, this paradigm has been challenged because not all pathological changes observed in the asthmatic airways are adequately explained simply as a result of Th2-mediated processes. Contemporary thought holds that asthma is a complex immune disorder involving innate as well as adaptive immune responses, with the clinical heterogeneity of asthma perhaps a result of the different relative contribution of these two systems to the disease. Epidemiological studies show that exposure to certain environmental substances is strongly associated with the risk of developing asthma. The airway epithelium is first barrier to interact with, and respond to, environmental agents (pollution, viral infection, allergens), suggesting that it is a key player in the pathology of asthma. Epithelial cells play a key role in the regulation of tissue homeostasis by the modulation of numerous molecules, from antioxidants and lipid mediators to growth factors, cytokines, and chemokines. Additionally, the epithelium is also able to suppress mechanisms involved in, for example, inflammation in order to maintain homeostasis. An intrinsic alteration or defect in these regulation mechanisms compromises the epithelial barrier, and therefore, the barrier may be more prone to environmental substances and thus more likely to exhibit an asthmatic phenotype. In support of this, polymorphisms in a number of genes that are expressed in the bronchial epithelium have been linked to asthma susceptibility, while environmental factors may affect epigenetic mechanisms that can alter epithelial function and response to environmental insults. A detailed understanding of the regulatory role of the airway epithelium is required to develop new therapeutic strategies for asthma that not only address the symptoms but also the underlining pathogenic mechanism(s) and prevent airway remodelling.

Cigarette smoke promotes eosinophilic inflammation, airway remodeling, and nasal polyps in a murine polyp model

BACKGROUND

Exposure to cigarette smoking (CS) is a major risk factor for airway inflammation. However, little is known about the effects of CS exposure on eosinophilic rhinosinusitis with nasal polyps (ERSwNPs). Histopathological and molecular studies were performed to investigate its effects using a murine model of ERSwNPs.

METHODS

Mice were assigned to one of the following four groups (n = 8 for each group): control group, CS exposure (CS group), ERSwNP (ERS group), and ERSwNPs exposed to CS (ERS + CS group). Histopathological changes were investigated using various stains, including hematoxylin and eosin for inflammation and polyp-like lesions, Sirius red for eosinophils, toluidine blue for mast cells, Alcian blue for goblet cells, and Masson's trichrome stain for collagen fibers. mRNA expression of cytokines from nasal mucosae was measured. Serum IgE and systemic cytokine levels were measured by enzyme-linked immunosorbent assays. The expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF) 1-alpha was evaluated by immunohistochemical staining.

RESULTS

The ERS + CS group showed more severe symptoms, increased the number of polyp-like lesions, infiltration of eosinophils, goblet cell hyperplasia, and subepithelial fibrosis, compared with the ERS group. Additionally, mRNA expressions of IL-4 and IL-17A were up-regulated in ERS + CS group and higher levels of IL-4, IL-6, IL-17A, and interferon gamma from splenocytes were observed significantly in the ERS + CS group compared with the ERS group. In the ERSwNP murine model, exposure to CS enhanced the expression of VEGF and HIF-1-alpha in nasal epithelial cells.

CONCLUSION

Chronic exposure to CS aggravated eosinophilic inflammation and promoted airway remodeling and nasal polyp formation in a murine model of ERSwNPs. The underlying mechanism might involve up-regulated expression of VEGF and HIF-1-alpha.

Anxiety sensitivity as a mediator of the association between asthma and smoking

OBJECTIVE

Despite its negative effects, smoking is more common among individuals with asthma compared to those without. Anxiety sensitivity (fear of arousal-related sensations) is associated with both smoking and asthma; however, no research, to date, has examined the interplay between these three factors. Thus, the purpose of the current study was to evaluate the mediating role of anxiety sensitivity in the association between asthma diagnosis and smoking status.

METHODS

The current study was a secondary analysis of data from three existing datasets of non-smokers and smokers with and without asthma (n = 433; 56.3% female, M(age) = 34.01 years, SD = 13.9). Participants provided information on their asthma diagnosis status and smoking status and completed self-report measures.

RESULTS

As hypothesized, after controlling for gender, race and age, there was a significant indirect effect of asthma diagnosis on smoking status through anxiety sensitivity (95% CI = 0.07-0.48).

CONCLUSIONS

These results indicate that the association between asthma diagnosis and smoking status appears to be driven, in part, by anxiety sensitivity and suggest that anxiety sensitivity may serve as an important target for prevention and intervention efforts for smokers with asthma.

Complementing the randomized controlled trial evidence base. Evolution not revolution

Observational studies and pragmatic trials can complement classical randomized controlled trials (RCTs) by providing data more relevant to the circumstances under which medicine is routinely practiced, thereby providing practical guidance for clinicians. The bearing of RCT findings on day-to-day practice can be weighted and the data more meaningfully interpreted by practicing clinicians if evidence is integrated from a variety of different study designs and methodologies. The advent of observational studies and pragmatic trials, often referred to as "real-life studies," has met with a degree of cynicism, but their role and value is gaining widespread recognition and support among clinicians. This article discusses where observational studies and pragmatic trials have utility, namely: in addressing clinical questions that are unanswered and/or unanswerable by RCTs; in testing new hypotheses and possible license extensions; and in helping to differentiate between available therapies for a given indication. Moreover, it seeks to highlight how the different approaches fit within a conceptual framework of evidence relevant to clinical practice, a step-change in the traditional view of medical evidence.

Mode of dendritic cell activation: the decisive hand in Th2/Th17 cell differentiation. Implications in asthma severity?

Asthma is a heterogeneous chronic inflammatory disease of the airways, with reversible airflow limitations and airway remodeling. The classification of asthma phenotypes was initially based on different combinations of clinical symptoms, but they are now unfolding to link biology to phenotype. As such, patients can suffer from a predominant eosinophilic, neutrophilic or even mixed eosinophilic/neutrophilic inflammatory response. In adult asthma patients, eosinophilic inflammation is usually seen in mild-to-moderate disease and neutrophilic inflammation in more severe disease. The underlying T cell response is predominated by T helper (Th) 2, Th17, or a mixed Th2/Th17 cell immune response. Dendritic cells (DCs) are "professional" antigen presenting cells (APCs), since their principal function is to present antigens and induce a primary immune response in resting naive T cells. DCs also drive the differentiation into distinctive Th subsets. The expression of co-stimulatory molecules and cytokines by DCs and surrounding cells determines the outcome of Th cell differentiation. The nature of DC activation will determine the expression of specific co-stimulatory molecules and cytokines, specifically needed for induction of the different Th cell programs. Thus DC activation is crucial for the subsequent effector Th immune responses. In this review, we will discuss underlying mechanisms that initiate DC activation in favor of Th2 differentiation versus Th1/Th17 and Th17 differentiation in the development of mild versus moderate to severe asthma.

Clinical characteristics of asthma combined with COPD feature

PURPOSE

In clinical practice, some patients with asthma show incompletely reversible airflow obstruction, resembling chronic obstructive pulmonary disease (COPD). The aim of this study was to analyze this overlap phenotype of asthma with COPD feature.

MATERIALS AND METHODS

A total of 256 patients, over the age of 40 years or more with a diagnosis of asthma, based on either 1) positive response to bronchodilator: >200 mL forced expiratory volume in 1 s (FEV₁) and >12% baseline or 2) positive methacholine or mannitol provocation test, were enrolled. Among the asthma patients, we defined the overlap group with incompletely reversible airflow obstruction [postbronchodilator FEV₁/forced vital capacity (FVC)<70] at the initial time of admission and continuing airflow obstruction after at least 3 months follow up. We evaluated clinical features, serum eosinophil counts, serum total immunoglobulin (Ig) E with allergy skin prick test, spirometry, methacholine or mannitol provocation challenges and bronchodilator responses, based on their retrospective medical record data. All of the tests mentioned above were performed within one week.

RESULTS

The study population was divided into two groups: asthma only (62%, n=159, postbronchodilator FEV₁/FVC≥70) and overlap group (38%, n=97, postbronchodilator FEV₁/FVC<70). The overlap group was older, and contained more males and a higher percentage of current or ex-smokers than the asthma only group. Significantly lower FEV₁ and higher total lung capacity, functional residual capacity, and residual volume were observed in the overlap group. Finally, significantly lower serum eosinophil count and higher IgE were seen in the overlap group.

CONCLUSION

Our results showed that the overlap phenotype was older, male asthmatic patients who have a higher lifetime smoking intensity, more atopy and generally worse lung function.

Smoking Behaviour of Asthmatic Patients in Primary Care: A Cross-Sectional Study

Introduction:

One-third of adult asthma patients smoke cigarettes despite smoking being a known trigger of asthma exacerbation. This study aims to describe the behaviour of asthmatic patients who smoke and explore the reasons why they continue to smoke cigarettes even when unwell.

Methods:

A cross-sectional questionnaire survey was conducted on adult asthma patients at primary care clinics in Singapore. One hundred and seventy-four asthmatic smokers (AS) of four ethnic groups, both genders, aged 21–50 years were recruited. Demographic data and smoking characteristics, reasons for smoking, and experiences during their attempts to quit were collected and analysed using the statistical software STATA version 12.

Results:

The median age of AS was 30 years. Seventy-five percent were males and mostly Malays (58%). Seventy-one percent had at least secondary education. Eighty-six percent started smoking before 20 years old. Ninety-eight percent smoked less than 10 sticks per day and 51% smoked ≤5 pack-years. Thirty-eight percent smoked within 5 minutes of awakening. AS cited reasons such as stress relief (79%), peer pressure (36%), influence from family members who smoke (40%), think better (35%), staying alert (57%), and relaxed (53%). Although 77% believed smoking worsened their asthma, they continued to smoke. Restlessness (43%), mood swings (27%), difficulties in concentration (25%) and irritability (24%) were common symptoms encountered in those who attempted to quit. About 44% did not refrain from smoking even when they were ill.

Conclusion:

Adult asthmatic smokers continued cigarette smoking to relieve stress, maintain mental alertness and avoid withdrawal symptoms. Implementing a programme to address smoking behaviour and withdrawal symptoms is paramount towards successful smoking cessation.

Prevalence of asthmatic smokers: Turkish experience (PASTE Study)

BACKGROUND

Although both asthma and smoking are major health problems worldwide, smokers are often excluded from asthma studies.

OBJECTIVES

It was aimed to verify the prevalence of asthmatic smokers in Turkey and assess the effects of smoking based on clinical parameters, exacerbations and hospitalizations because of lack of national data about the prevalence of smoking among asthmatics.

METHODS

The study protocol was comprised of a retrospective questionnaire. The asthmatic patients were followed in the outpatient clinics of 18 tertiary hospitals selected from seven different geographical regions in Turkey. We evaluated demographic data, smoking habits, asthma-related diseases, respiratory function and emergency visits.

RESULTS

The study population included 1385 patients (M/F: 343/1042), and the mean age was 45.1 ± 14.0 years. Current and former smoking prevalence was 11.4% and 15.1%, respectively. Smoker rates were higher in males and younger asthmatics compared with females and older asthmatics (P < 0.01 and P < 0.05, respectively). Smoking history ranged from 0.20 to 90 pack-years (the mean was 12.9), and smokers had a higher level of education compared with nonsmokers (P < 0.01). Socioeconomically, the most developed region had the highest rate of smoker asthmatics (33.9%; P = 0.014). There was an increase in the number of exacerbations in smoker asthmatics during the previous year, but it was not statistically significant (P > 0.05).

CONCLUSION

We showed that the smoking prevalence in Turkey was lower in asthmatics (11.4%) compared with the general population (44.5%). Nevertheless, every effort should be made to encourage asthmatics to stop smoking because smoking is a modifiable risk factor for adverse asthma health outcomes.

Glucocorticoid-resistant asthma: more than meets the eye

INTRODUCTION

For decades glucocorticoids have been considered as the gold standard for the treatment of asthma. We present a case report of typical glucocorticoid-resistant asthma and current consensus in definitions of "severe refractory", "difficult" and "glucocorticoid-resistant" asthma.

METHODS

Full-text papers and abstracts were identified on the basis of a comprehensive literature search primarily in MEDLINE (1966 to June 2012) but also in the Cochrane Central Register of Controlled Trials database.

RESULTS

Glucocorticoid-resistant asthmatics are a small subset of patients who pose noteworthy diagnostic challenges while contributing disproportionately to health care costs. Recognition of various asthma phenotypes has aided in characterizing groups with severe asthma and given a better understanding of its pathophysiological process. The molecular mechanism of glucocorticoid action is complicated and several pathways have been identified to explain drug resistance, which in turn is crucial for drug development. Tobacco smoking appears to be the single most important contributor of glucocorticoid resistance. We present the emerging and promising concepts in the management of glucocorticoid-resistant asthma, which mainly include drugs targeting specific molecules, receptors, inflammatory cells or immune processes.

CONCLUSION

The challenges in making a diagnosis of glucocorticoid-resistant asthma may contribute to underestimating its prevalence and impact on patient care. Considerable progress has been made in identifying distinct phenotypes and mechanisms of glucocorticoid resistance; therefore the future of new drug development in management of asthma is promising.

Inflammation and corticosteroid responsiveness in ex-, current- and never-smoking asthmatics

BACKGROUND

It has been suggested that smoking asthmatics benefit less from corticosteroid treatment than never-smoking asthmatics. We investigated differences in blood and sputum inflammatory profiles between ex-, current-, and never-smokers and assessed their ICS treatment response after 2-week and 1-year treatment.

METHODS

We analyzed FEV1, PC20 methacholine and PC20 AMP, (differential) cell counts in sputum and blood in ex-, current- and never-smokers at baseline (n=114), after 2-week treatment with fluticasone 500 or 2000 μg/day (n=76) and after 1-year treatment with fluticasone 500 μg/day or a variable dose of fluticasone based on a self-management plan (n=64).

RESULTS

A total of 114 patients were included (29 ex-, 30 current- and 55 never-smokers. At baseline, ex- and current-smokers had less eosinophils in sputum and blood than never-smokers. Blood neutrophil counts were higher in current- than in never-smokers. A higher number of cigarettes smoked daily was associated with lower blood and sputum eosinophils. After 2-week ICS treatment, FEV1 %predicted improved less in current-smokers than never-smokers (2.4% versus 8.1%, p=0.010) and ex-smokers tended to improve less than never-smokers (4.1%, p=0.067). In contrast, no differences in ICS treatment response in lung function or inflammatory cells were found between the three groups after 1 year.

CONCLUSIONS

Ex- and current-smokers have less eosinophils and more neutrophils in their sputum and blood than never-smokers. Although ex- and current-smokers have a reduced short-term corticosteroid treatment response, we did not find a difference in their long-term treatment response.

Age-specific characteristics of inpatients with severe asthma exacerbation

BACKGROUND

The characteristics of inpatients with severe asthma exacerbation remain unclear. It is considered that the characteristics of inpatients with severe asthma vary depending on age. However, these are rarely investigated. The objective of this study is to investigate the differences in characteristics among different age groups. We considered that it is necessary to understand the characteristics of each age group so that we can establish strategies in preventing severe asthma exacerbation.

METHODS

All asthma inpatients who were hospitalized between 2004 and 2011 with SpO2 <90% (in room air), were breathless at rest, and showed increased respiratory rate and pulse rate were examined. We compared the characteristics among the young age group, middle age group, and advanced age group.

RESULTS

The total number of patients was 204. In the young age group, the percentages of patients with irregular visits and non visits to a medical institution were high. This group showed high percentages of smokers and pet owners. The percentage of continuous ICS users in this group was 25.9%. The middle age group had high rates of aspirin-intolerant asthma. The percentage of continuous ICS users in this group was 60.2%. In the advanced age group, the percentages of patients with hypertension/heart disease, diabetes mellitus, and COPD were high. This group showed good treatment adherence. The percentage of continuous ICS users in this group was 77.4%.

CONCLUSIONS

The characteristics of inpatients with severe asthma vary depending on age. We need to establish countermeasures for asthma exacerbation according to the characteristics of patients depending on age.

Smoking in asthma is associated with elevated levels of corticosteroid resistant sputum cytokines-an exploratory study

Background

Current cigarette smoking is associated with reduced acute responses to corticosteroids and worse clinical outcomes in stable chronic asthma. The mechanism by which current smoking promotes this altered behavior is currently unclear. Whilst cytokines can induce corticosteroid insensitivity in-vitro, how current and former smoking affects airway cytokine concentrations and their responses to oral corticosteroids in stable chronic asthma is unclear.

Objectives

To examine blood and sputum cytokine concentrations in never, ex and current smokers with asthma before and after oral corticosteroids.

Methods

Exploratory study utilizing two weeks of oral dexamethasone (equivalent to 40 mg/day prednisolone) in 22 current, 21 never and 10 ex-smokers with asthma. Induced sputum supernatant and plasma was obtained before and after oral dexamethasone. 25 cytokines were measured by multiplex microbead system (Invitrogen, UK) on a Luminex platform.

Results

Smokers with asthma had elevated sputum cytokine interleukin (IL) -6, -7, and -12 concentrations compared to never smokers with asthma. Few sputum cytokine concentrations changed in response to dexamethasone IL-17 and IFNα increased in smokers, CCL4 increased in never smokers and CCL5 and CXCL10 reduced in ex-smokers with asthma. Ex-smokers with asthma appeared to have evidence of an ongoing corticosteroid resistant elevation of cytokines despite smoking cessation. Several plasma cytokines were lower in smokers with asthma compared to never smokers with asthma.

Conclusion

Cigarette smoking in asthma is associated with a corticosteroid insensitive increase in multiple airway cytokines. Distinct airway cytokine profiles are present in current smokers and never smokers with asthma and could provide an explanatory mechanism for the altered clinical behavior observed in smokers with asthma.

Can we predict sputum eosinophilia from clinical assessment in patients referred to an adult asthma clinic?

BACKGROUND

There is overwhelming evidence that asthma guidelines aimed at reducing airway inflammation are superior to those based on clinical symptoms alone. This involves targeting eosinophilic inflammation with inhaled corticosteroids.

AIM

Because induced sputum is not readily available, our study set out to investigate whether the collective or singular use of routine asthma investigations can predict sputum eosinophilia.

METHODS

Eighty patients underwent skin prick testing, blood tests (IgE, full blood count), spirometry, exhaled fraction nitric oxide (FeNO), PD15 to hypertonic saline, and induced sputum testing at first assessment. A predictive model for sputum eosinophilia (defined as ≥3% eosinophils) was sought using routinely available tests.

RESULTS

Fifty-four subjects underwent both induced sputum and FeNO testing. Seventeen (30%) revealed eosinophilic inflammation, nine (16%) neutrophilic, four (7%) mixed granulocytic and 26 (46%) paucigranulocytic. Positive predictors for sputum eosinophilia included low forced expiratory volume in 1 s (FEV(1))% predicted, raised serum eosinophil, positive smoking history, Polynesian ethnicity and negative asthma family history. There was a non-statistically significant trend for FeNO predicting sputum eosinophilia. The best combination of predictors was low FEV(1)% predicted, raised serum eosinophil, positive smoking history and negative family history of asthma.

CONCLUSION

This study demonstrates that the serum eosinophil count and FEV(1) combined with aspects of a clinical history may provide a simple and practical alternative to assessment of airway (sputum) eosinophilia in the clinical setting. A full blood count can be performed at a substantially lesser cost and with greater accessibility than induced sputum. We feel the time has come for the clinical utility of the serum eosinophil count to be revisited.

Epidemiology of asthma in the United States

Incidence and prevalence rates of asthma can vary greatly according to population and location. The National Heart and Blood Institute of the National Institutes of Health defines asthma as a common chronic disorder of the airways that involves a complex interaction of airflow obstruction, bronchial hyperresponsiveness, and an underlying inflammation. This article uses the most common definitions and diagnostic methods for asthma. In 2009 there were 2.1 million asthma-related emergency department (ED) visits. ED visits lend an opportunity for providers to identify and intervene in the care of patients whose asthma is poorly controlled.