Does smoking affect the outcome of patient education and self-management in asthmatics?

The impact of exposure to tobacco smoke and e-cigarettes on asthma-related outcomes: Systematic review informing the EAACI guidelines on environmental science for allergic diseases and asthma

To inform the clinical practice guidelines' recommendations developed by the European Academy of Allergy and Clinical Immunology systematic reviews (SR) assessed using GRADE on the impact of environmental tobacco smoke (ETS) and active smoking on the risk of new-onset asthma/recurrent wheezing (RW)/low lung function (LF), and on asthma-related outcomes. Only longitudinal studies were included, almost all on combustion cigarettes, only one assessing e-cigarettes and LF. According to the first SR (67 studies), prenatal ETS increases the risk of RW (moderate certainty evidence) and may increase the risk of new-onset asthma and of low LF (low certainty evidence). Postnatal ETS increases the risk of new-onset asthma and of RW (moderate certainty evidence) and may impact LF (low certainty evidence). Combined in utero and postnatal ETS may increase the risk of new-onset asthma (low certainty evidence) and increases the risk of RW (moderate certainty evidence). According to the second SR (24 studies), ETS increases the risk of severe asthma exacerbations and impairs asthma control and LF (moderate certainty evidence). According to the third SR (25 studies), active smoking increases the risk of severe asthma exacerbations and of suboptimal asthma control (moderate certainty evidence) and may impact asthma-related quality-of-life and LF (low certainty evidence).

Acceptance and Dropout Rates of Individuals with Asthma Approached in Self-management Interventions: A Systematic Review and Meta-analysis

Objective

The objectives of this systematic review were to assess the acceptability of self-management interventions for people with asthma and identify contributing factors.

Methods

A systematic literature search was conducted using PubMed, MEDLINE, EMBASE (OVIDWEB), CINAHL and Cochrane databases. Clinical trials design was included if they met specified criteria. A random-effect meta-regression analysis was conducted to estimate the overall acceptance and drop-out rates and to assess the potential factors that may influence the outcomes.

Results

A total of 64 studies were included and 8,092 participants were recruited and participated in the trials. The estimated acceptance rate was 51.1%, while the estimated drop-out rates in the intervention and control groups were 18.2% and 15.6%, respectively. Lack of interest was the main reported reason for refusing to participate and dropping out from the program. Study-related and program-related factors influenced the acceptance and drop-out rates statistically and clinically.

Conclusion

The acceptance rate of self-management programs among asthmatic people was not high and the dropout rate was somewhat low. The review suggests optimizing the design of self-management studies and modifying the implemented self-management programs to increase the acceptance rate and decrease the dropout rate.

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.

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.

Association between periodontitis and severe asthma in adults: A case-control study

OBJECTIVE

To evaluate the association between periodontitis and severe asthma, with participants in treatment for severe asthma, controlled by therapy.

METHODS

A case-control investigation was performed to compare 130 adults with severe asthma with 130 without asthma. Individuals with periodontitis were those with ≥4 teeth with ≥1 site with probing depth ≥4 mm, clinical attachment level ≥3 mm, and bleeding upon probing at the same site. Severe asthma diagnosis was based on Global Initiative for Asthma criteria.

RESULTS

Association between exposure to periodontitis and severe asthma was found: OR_crude  = 2.98 (95% CI: 1.74-5.11). When confounders were considered, the association between exposure to periodontitis and severe asthma was maintained: OR_adjusted  = 3.01-3.25. Individuals with periodontitis had about a threefold increased risk of severe asthma than those without periodontitis. Frequency of periodontitis in participants with severe asthma was greater than that of those without asthma (46.6% vs 22.3%, p ≤ .05).

CONCLUSIONS

Association between periodontitis and severe asthma was observed. Further investigation is required to determine the direction of this relationship. It may be causal, but it may also be a consequence of the immunopathological process that characterizes asthma, or else, consequence of the medication used for treatment.

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.

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 medication use among late midlife U.S. Adults

OBJECTIVE

Despite substantial prevalence of asthma, little is known about asthma in late midlife adults (50-64 years). The objective of this study was to examine the factors associated with the use of asthma medications among late midlife adults.

METHODS

Pooled data were obtained from the 2006 to 2010 Medical Expenditure Panel Survey. Medication use outcome variables include: (a) daily use of a preventive asthma medication and (b) use of more than three canisters of rescue inhalers in last 3 months. The Andersen Behavioral Model of Health Services Utilization was used to guide the selection of independent variables. Descriptive, unadjusted and adjusted logistic regression analyses were performed. Point estimates were weighted to the US civilian population and variance estimates were adjusted to obtain appropriate standard errors. All analyses were conducted using STATA (version 12).

RESULTS

A total of 1414 (weighted sample of 15,030,364) self-reported late midlife asthmatics were identified. About 31% of late midlife adults with asthma were using a preventive medication on a daily basis while 11% reported overusing acute medications. Adjusted analyses found that race, rurality and smoking were related to poor use of asthma medications among late midlife adults.

CONCLUSION

Results suggest that asthma medication use is far from optimal among vulnerable groups of late midlife US adults.

Chronic disease management programmes for adults with asthma

BACKGROUND

The burden of asthma on patients and healthcare systems is substantial. Interventions have been developed to overcome difficulties in asthma management. These include chronic disease management programmes, which are more than simple patient education, encompassing a set of coherent interventions that centre on the patients' needs, encouraging the co-ordination and integration of health services provided by a variety of healthcare professionals, and emphasising patient self-management as well as patient education.

OBJECTIVES

To evaluate the effectiveness of chronic disease management programmes for adults with asthma.

SEARCH METHODS

Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register, MEDLINE (MEDLINE In-Process and Other Non-Indexed Citations), EMBASE, CINAHL, and PsycINFO were searched up to June 2014. We also handsearched selected journals from 2000 to 2012 and scanned reference lists of relevant reviews.

SELECTION CRITERIA

We included individual or cluster-randomised controlled trials, non-randomised controlled trials, and controlled before-after studies comparing chronic disease management programmes with usual care in adults over 16 years of age with a diagnosis of asthma. The chronic disease management programmes had to satisfy at least the following five criteria: an organisational component targeting patients; an organisational component targeting healthcare professionals or the healthcare system, or both; patient education or self-management support, or both; active involvement of two or more healthcare professionals in patient care; a minimum duration of three months.

DATA COLLECTION AND ANALYSIS

After an initial screen of the titles, two review authors working independently assessed the studies for eligibility and study quality; they also extracted the data. We contacted authors to obtain missing information and additional data, where necessary. We pooled results using the random-effects model and reported the pooled mean or standardised mean differences (SMDs).

MAIN RESULTS

A total of 20 studies including 81,746 patients (median 129.5) were included in this review, with a follow-up ranging from 3 to more than 12 months. Patients' mean age was 42.5 years, 60% were female, and their asthma was mostly rated as moderate to severe. Overall the studies were of moderate to low methodological quality, because of limitations in their design and the wide confidence intervals for certain results.Compared with usual care, chronic disease management programmes resulted in improvements in asthma-specific quality of life (SMD 0.22, 95% confidence interval (CI) 0.08 to 0.37), asthma severity scores (SMD 0.18, 95% CI 0.05 to 0.30), and lung function tests (SMD 0.19, 95% CI 0.09 to 0.30). The data for improvement in self-efficacy scores were inconclusive (SMD 0.51, 95% CI -0.08 to 1.11). Results on hospitalisations and emergency department or unscheduled visits could not be combined in a meta-analysis because the data were too heterogeneous; results from the individual studies were inconclusive overall. Only a few studies reported results on asthma exacerbations, days off work or school, use of an action plan, and patient satisfaction. Meta-analyses could not be performed for these outcomes.

AUTHORS' CONCLUSIONS

There is moderate to low quality evidence that chronic disease management programmes for adults with asthma can improve asthma-specific quality of life, asthma severity, and lung function tests. Overall, these results provide encouraging evidence of the potential effectiveness of these programmes in adults with asthma when compared with usual care. However, the optimal composition of asthma chronic disease management programmes and their added value, compared with education or self-management alone that is usually offered to patients with asthma, need further investigation.

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.

Does periodontal infection have an effect on severe asthma in adults?

BACKGROUND

The effect of periodontal infection on systemic diseases and conditions has been the subject of numerous studies worldwide. It is considered that periodontitis may influence the hyperinflammatory response in patients with severe asthma as a result of immuno-inflammatory changes. This study aims to evaluate the influence of periodontitis on severe asthma in adults.

METHODS

A case-control study was carried out, comprising 220 adult individuals: 113 diagnosed with asthma (case group) and 107 without asthma diagnosis (control group). The diagnosis of periodontitis was established after a full clinical examination using probing depth, clinical attachment level, and bleeding on probing. The diagnosis of severe asthma was based on the criteria recommended by the Global Initiative of Asthma (2012). Descriptive analyses of the variables were performed, followed by bivariate analyses, using the χ(2) test. Association measurements (odds ratio [OR]), with and without adjustment for potential confounders, were obtained. A significance level of 5% was used.

RESULTS

The ORunadjusted for the main association was 4.38 (95% confidence interval [CI] = 2.47 to 7.75). In the logistic regression model, after adjusting for age, education level, osteoporosis, smoking habit, and body mass index, the ORadjusted was 4.82 (95% CI = 2.66 to 8.76), which was statistically significant. Individuals with periodontal infection showed, approximately, five times more likelihood to have bronchial inflammation than those without such periodontal tissue infection.

CONCLUSION

The findings demonstrate the influence of periodontitis on severe asthma, given that the frequency of periodontitis is higher in individuals with severe asthma than in those without a diagnosis of bronchial inflammation.

Impact of atopy on asthma and allergic rhinitis in the cohort for reality and evolution of adult asthma in Korea

PURPOSE

Atopy is an important cause of asthma. Few data on the prevalence of atopy or comparisons with clinical characteristics of asthma in Korean patients have been published. We evaluated the effects of atopy on clinical profiles and airway inflammation in Korean asthmatics.

METHODS

We retrospectively enrolled 1,492 asthmatics from the Cohort for Reality and Evolution of Adult Asthma in Korea (COREA) cohort who had undergone skin prick tests for aeroallergens. The patients' clinical characteristics, lung function, PC20, and sputum and blood inflammatory cell counts were compared based on the presence or absence of atopy. Atopy was defined as one or more positive reactions (A/H ratio >1) on a skin prick test.

RESULTS

Among 11 aeroallergens, house dust mites (Dermatophagoides farinae and Dermatophagoides pteronyssinus) were the most prevalent cause of a positive skin prick test. As compared with non-atopic asthmatics, atopic asthmatics showed early onset of the disease. Atopic patients with asthma had a higher FEV1, FVC, and FEV1/FVC as compared with non-atopic patients with asthma. In addition, asthmatics without atopy had more uncontrolled asthma (P=0.001) and severe rhinitis (P<0.05) as compared with atopic asthmatics. Smoking, as measured in pack years, was higher in the non-atopic asthmatics than in the atopic asthmatics. The erythrocyte sedimentation rate was higher in non-atopic asthmatics than in the atopic asthmatics and patients with non-atopic asthma had a higher sputum neutrophil count than did those with atopic asthma.

CONCLUSIONS

Our data indicate that atopic asthmatics had an early onset of disease and high IgE levels, while the non-atopic asthmatics had decreased lung function and a high sputum neutrophil count, suggesting that a different approach is needed to treat atopic asthma.

Asthma outcomes: quality of life

BACKGROUND

"Asthma-related quality of life" (QOL) refers to the perceived impact that asthma has on the patient's QOL.

OBJECTIVE

National Institutes of Health institutes and other federal agencies convened an expert group to recommend standardized measures of the impact of asthma on QOL for use in future asthma clinical research.

METHODS

We reviewed published documentation regarding the development and psychometric evaluation; clinical research use since 2000; and extent to which the content of each existing QOL instrument provides a unique, reliable, and valid assessment of the intended construct. We classified instruments as core (required in future studies), supplemental (used according to the study's aims and standardized), or emerging (requiring validation and standardization). This work was discussed at an National Institutes of Health-organized workshop convened in March 2010 and finalized in September 2011.

RESULTS

Eleven instruments for adults and 6 for children were identified for review. None qualified as core instruments because they predominantly measured indicators of asthma control (symptoms and/or functional status); failed to provide a distinct, reliable score measuring all key dimensions of the intended construct; and/or lacked adequate psychometric data.

CONCLUSIONS

In the absence of existing instruments that meet the stated criteria, currently available instruments are classified as either supplemental or emerging. Research is strongly recommended to develop and evaluate instruments that provide a distinct, reliable measure of the patient's perception of the impact of asthma on all of the key dimensions of QOL, an important outcome that is not captured in other outcome measures.

The effects of cigarette smoke on airway inflammation in asthma and COPD: therapeutic implications

Asthma and COPD are two chronic inflammatory disorders of the airway characterized by airflow limitation. While many similarities exist between these two diseases, they are pathologically distinct due to the involvement of different inflammatory cells; predominantly neutrophils, CD8 lymphocytes in COPD and eosinophils and CD4 lymphocytes in asthma. Cigarette smoking is associated with accelerated decline of lung function, increased mortality, and worsening of symptoms in both asthma and COPD. Furthermore, exposure to cigarette smoke can alter the inflammatory mechanisms in asthma to become similar to that seen in COPD with increasing CD8 cells and neutrophils and may therefore alter the response to therapy. Cigarette smoke exposure has been associated with a poor response to inhaled corticosteroids which are recommended as first line anti-inflammatory medications in asthma and as an add-on therapy in patients with severe COPD with history of exacerbations. While the main proposed mechanism for this altered response is the reduction of the histone deacetylase 2 (HDAC2) enzyme system, other possible mechanisms include the overexpression of GR-β, activation of p38 MAPK pathway and increased production of inflammatory cytokines such as IL-2, 4, 8, TNF-α and NF-Kß. Few clinical trials suggest that leukotriene modifiers may be an alternative to corticosteroids in smokers with asthma but there are currently no drugs which effectively reduce the progression of inflammation in smokers with COPD. However, several HDAC2 enhancers including low dose theophylline and other potential anti-inflammatory therapies including PDE4 inhibitors and p38 MAPK inhibitors are being evaluated.

Reassessing the evidence hierarchy in asthma: evaluating comparative effectiveness

Classical randomized controlled trials are the gold standard in medical evidence because of their high internal validity. However, their necessarily strict design can limit their external validity and the ability to extrapolate these data to real world patients. Therefore, alternatively designed studies may play a complementary role in evaluating the comparative effectiveness of therapies in nonidealized patients in more naturalistic, real world settings. Observational studies have high external validity and can evaluate real world outcomes. Their strength lies in hypothesis generation and testing and in identifying areas in which further clinical trials may be required. Pragmatic trials are designed to maximize applicability of trial results to usual care settings by relying on clinically important outcomes and enrolling a wide range of participants. A combination of these approaches is preferable and necessary.

A children's asthma education program: Roaring Adventures of Puff (RAP), improves quality of life

BACKGROUND

It is postulated that children with asthma who receive an interactive, comprehensive education program would improve their quality of life, asthma management and asthma control compared with children receiving usual care.

OBJECTIVE

To assess the feasibility and impact of 'Roaring Adventures of Puff' (RAP), a six-week childhood asthma education program administered by health professionals in schools.

METHODS

Thirty-four schools from three health regions in Alberta were randomly assigned to receive either the RAP asthma program (intervention group) or usual care (control group). Baseline measurements from parent and child were taken before the intervention, and at six and 12 months.

RESULTS

The intervention group had more smoke exposure at baseline. Participants lost to follow-up had more asthma symptoms. Improvements were significantly greater in the RAP intervention group from baseline to six months than in the control group in terms of parent's perceived understanding and ability to cope with and control asthma, and overall quality of life (P<0.05). On follow-up, doctor visits were reduced in the control group.

CONCLUSION

A multilevel, comprehensive, school-based asthma program is feasible, and modestly improved asthma management and quality of life outcomes. An interactive group education program offered to children with asthma at their school has merit as a practical, cost-effective, peer-supportive approach to improve health outcomes.

Smoking and nonsmoking asthma: differences in clinical outcome and pathogenesis

Cigarette smoking in asthma is frequently present and is associated with worsening of symptoms, accelerated lung-function decline, a higher frequency of hospital admissions, a higher degree of asthma severity, poorer asthma control and reduced responsiveness to corticosteroids. Furthermore, it is associated with reduced numbers of eosinophils and higher numbers of mast cells in the submucosa of the airway wall. Airway remodeling is increased as evidenced by increased epithelial thickness and goblet cell hyperplasia in smoking asthmatics. The pathogenesis responsible for smoking-induced changes in airway inflammation and remodeling in asthma is complex and largely unknown. The underlying mechanism of reduced corticosteroid responsiveness is also unknown. This article discusses differences between smoking and nonsmoking asthmatics regarding the clinical expression of asthma, lung function, response to corticosteroids, airway inflammation and remodeling processes. Possible pathogenetic mechanisms that may explain the links between cigarette smoking and changes in the clinical expression of asthma will be discussed, as well as the beneficial effects of smoking cessation.

Allergen inhalation challenge in smoking compared with non-smoking asthmatic subjects

BACKGROUND

Smoking asthmatics experience more severe symptoms, require more rescue medication and have more asthma-related hospitalizations than non-smoking asthmatics. However, studies in mice suggest that mainstream cigarette smoke may reduce airway inflammation and may attenuate airway hyperresponsiveness. A comparison of allergen-induced airway inflammatory responses of smoking and non-smoking atopic asthmatics has not been examined previously.

OBJECTIVES

To determine whether allergen-induced airway responses and inflammatory profiles are attenuated in smoking when compared with non-smoking mild allergic asthmatic subjects.

METHODS

Allergen inhalation challenges were performed in 13 smoking and 19 non-smoking mild allergic asthmatic subjects. The forced expired volume in 1 s (FEV(1) ) was measured up to 7 h after allergen inhalation. Methacholine airway responsiveness was measured before and at 24 h after allergen and sputum was induced before and at 7 and 24 h after allergen.

RESULTS

Both the smoking and non-smoking groups developed similar allergen-induced falls in FEV(1) during the early and late asthmatic responses and similar increases in allergen-induced airway eosinophils. The mean maximum fall in FEV(1) during the late response was 16.3 ± 4.3% in non-smokers and 12.9 ± 7.2% in smokers. The smoking asthmatics, however, did not develop allergen-induced methacholine airway hyperresponsiveness, whereas the non-smoking controls developed a 1.18 doubling dose shift in methacholine PC(20) (P < 0.05).

CONCLUSIONS AND CLINICAL RELEVANCE

Mild allergic asthmatic subjects, who were current smokers with a mean 6-year pack history, develop allergen-induced eosinophilic airway inflammation and late responses, similar in magnitude to non-smoking asthmatics, but do not develop methacholine airway hyperresponsiveness associated with the allergen-induced airway eosinophilia.

Effects of smoking cessation on airflow obstruction and quality of life in asthmatic smokers

Purpose

Smoking elicits airway inflammation and airflow obstruction in patients with asthma, even after smoking cessation. The aim of this study was to examine the effects of smoking cessation on lung function and quality of life (QOL) in asthmatic patients.

Methods

Thirty-two patients with asthma who were active smokers were recruited. After education on the effects of smoking on asthma, 22 patients continued to smoke, and 10 quit smoking. All patients were treated with inhaled fluticasone propionate (1 mg/day) for 3 months. We compared forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity (FVC), forced expiratory flow between 25 and 75% FVC (FEF_25-75%), and scores on a QOL questionnaire at baseline, 1, 2, and 3 months.

Results

Quitters showed a greater percent change in FEV1 (19.1±6.3 vs. 7.9±2.4%, P=0.024) and FEV1/FVC (6.5±4.14 vs. 3.5±1.5%, P=0.05) than smokers. Both quitters and smokers showed improved QOL scores after 1, 2, and 3 months of fluticasone treatment.

Conclusions

Patients with asthma who quit smoking showed less airway obstruction, suggesting that smoking cessation is crucial in the management of asthma.

Asthma and cigarette smoking: a review of the empirical literature

The purpose of this review paper is to present and evaluate the empirical literature on the association between asthma and cigarette smoking. The authors conducted a literature search utilizing electronic search engines (i.e., PsycINFO and MEDLINE) to examine databases using the following key word algorithms: smoking OR nicotine OR tobacco AND asthma. Only articles that focused on active tobacco smoking and analyzed groups with asthma patients only were examined in the present review. Overall, empirical evidence suggests that (1) smoking is more prevalent among individuals with asthma than those without; (2) smoking is a risk candidate for the development of asthma; (3) smoking is associated with decreased asthma control and increased risk of mortality and asthma attacks and exacerbations; (4) smokers with and without asthma may have different risk factors for smoking onset as well as different smoking motives and outcome expectancies; and (5) smoking cessation is associated with improvements in lung functioning and asthma symptoms. Future work in this domain of study will lead to clinically relevant health care advances as well as the development of theoretically driven, methodologically diverse lines of research exploring asthma-smoking comorbidity issues.

Impact of comorbidities on asthma

Asthma is a common and serious illness with suboptimal outcomes of care. Epidemiological studies show certain comorbidities occurring more frequently than expected with asthma, with some being associated with poor control and a differential response to therapy options. This review summarizes the evidence of clinically important comorbidities, focusing on the best-explored conditions, including rhinitis and rhinosinusitis, anxiety and depression, obesity, gastroesophageal reflux, smoking and dysfunctional breathing. The evidence of epidemiological and pathophysiological associations for these comorbidities is explored, and the practical therapeutic implications are considered. Comorbidities are important for clinicians treating asthma as they may be markers of patients at risk of poor outcomes, they may point to specific effective treatment options and they are important to researchers as possible confounding factors in clinical trials.

A child's asthma quality of life rating does not significantly influence management of their asthma

BACKGROUND

Children of parents who perceive their children have increased asthma severity use more medical services and reliever medication.

METHODS

A randomized control trial of the Roaring Adventures of Puff (RAP) education program was completed among 287 grade 2-5 children with asthma. Parents and children completed a quality of life (QOL) questionnaire pre-intervention, 6 and 12 months post-intervention. We hypothesized that RAP altered how parent's assessed their child's QOL with a resultant change in asthma management.

RESULTS

Pre-intervention, parents rated their child's overall QOL higher than their child (parent 5.41 [95% CI 5.24, 5.58] vs. child 4.54 [95% CI 4.32, 4.75]; P < 0.001: paired t-test). For every point increase in the parent's overall QOL score, the child was 36% less likely to receive inhaled corticosteroids in the prior 2 weeks (OR 0.64, 95% CI 0.46, 0.88; P = 0.024) and 46% less likely to have missed school due to asthma in the prior 6 months (OR 0.54, 95% CI 0.36, 0.82; P = 0.016: logistic regression). The child's QOL assessment, beyond that provided by their parent, was not associated with the asthma management outcomes examined. The RAP program decreased parent's symptoms QOL assessment by an improvement of 0.45 on a 7-point scale greater than control at 6 months (95% CI -0.81, -0.09; P = 0.06). Moreover, the RAP interaction on parent symptoms rating was important in determining whether the child received a short-acting beta-agonist in the prior 2 weeks (P = 0.05).

CONCLUSIONS

Parent's QOL perception, and not the child's, is associated with asthma management. RAP decreased the parent's QOL symptoms assessment and was important in determining the child's asthma management.

Linkage between smoking and asthma

Smoking is one of the most important preventable public health problems. Prevalence of smoking is decreasing in the Western world but lot of work is left. We reviewed the most important papers related to smoking and asthma. Despite of decreasing smoking figures in Finland, about 15-20 per cent of pregnant women smokes. Children's exposure to harmful effects of environmental tobacco smoke (ETS) still continues. Exposure to tobacco smoke during pregnancy and in early childhood both deteriorates permanently children's lungs and increases their asthma risk. The exposure of adults to ETS also increases their asthma risk. Both passive exposure to ETS and active smoking worsen asthma. In addition, smoking asthmatics run a higher risk of developing COPD compared to non-smokers. Smoking prevalence among the population can be regulated through legislation, but the health care personnel have a central role in encouraging smoking cessation among smoking patients.

Prevalence of active and passive smoking in a population of patients with asthma

Smoking causes an intense inflammatory reaction in the airways and is associated with worse clinical outcomes in patients with asthma. The objective of this study was to determine the prevalence of active and passive smoking in a population of patients with asthma. The sample of asthma patients (n = 100) consisted of 47 nonsmokers, 33 former smokers, 17 passive smokers and 3 active smokers. Most had moderate or severe asthma. Mean exhaled CO was 9.34 ppb in smokers, 4.19 ppb in passive smokers, 3.98 ppb in nonsmokers and 3.98 ppb in former smokers. We conclude that the prevalence of exposure to tobacco smoke is high among asthma patients.

The impact of smoking on clinical and therapeutic effects in asthmatics

Smoking is associated with poor symptom control and impaired therapeutic responses in asthma. A total of 843 patients with asthma were recruited. The patients received treatment for 1 yr according to the severity of their asthma. We compared the forced expiratory volume in 1 sec (FEV1), the ratio of FEV1 to forced vital capaity (FVC), atopy, total IgE, emphysema on high-resolution computed tomography (HRCT), the number of near-fatal asthma attacks, and physiological fixed airway obstruction between the smoking and nonsmoking groups. The study population consisted of 159 (18.8%) current smokers, 157 (18.7%) ex-smokers, and 525 (62.5%) nonsmokers. Although the prevalence of atopy was not different between the smoking and nonsmoking groups, the total IgE was higher among the smokers than the nonsmokers. Compared with the nonsmoking group, the smokers had a lower FEV1 % predicted and forced expiratory flow between 25 and 75% of FVC. A greater prevalence of emphysema and a significantly higher number of asthmatic patients with fixed airway obstruction were detected in the smoking versus nonsmoking group. The 37.5% of asthmatic patients who were former or current smokers showed decreased pulmonary function and increased IgE, emphysema on HRCT, and fixed airway obstruction, indicating that smoking can modulate the clinical and therapeutic responses in asthma.

Persistent impact of cigarette smoking on asthma

OBJECTIVE

In the present study we assessed the impact of former cigarette smoking on asthma control and treatment effectiveness.

METHODS

A total of 104 patients with uncontrolled asthma were included in the study. The group of former smokers consisted of 33 subjects, whereas the never smokers group consisted of 71 subjects of similar age and gender. Spirometry, classification of asthma severity, and control were assessed according to Global Initiative for Asthma (GINA) guidelines. Quality of life was measured with the use of the Saint George Hospital Respiratory Questionnaire (SGHRQ).

RESULTS

Asthma was more severe in the group of former smokers both before and after treatment; p < 0.001. Severe asthma (OR 7.8 CI 2.8-21.9) and cigarette smoking (OR 3.5 CI 1.3-9.2) were associated with difficulties in asthma control achievement. Total quality of life significantly improved in the group of non-smokers; p = 0.02, whereas in former smokers this effect was not significant; p > 0.05.

CONCLUSION

Cigarette smoking has a persistent, dose-dependent, negative impact on the response to treatment in patients with uncontrolled asthma even after smoking cessation. Smoking cessation should remain the ultimate goal in treatment of asthmatic patients. More efforts should be undertaken to decrease smoking initiation, especially in teenagers.

Airway biomarkers of the oxidant burden in asthma and chronic obstructive pulmonary disease: current and future perspectives

The pathogenesis of asthma and chronic obstructive pulmonary disease (COPD) has been claimed to be attributable to increased systemic and local oxidative stress. Detection of the oxidant burden and evaluation of their progression and phenotypes by oxidant biomarkers have proved challenging and difficult. A large number of asthmatics are cigarette smokers and smoke itself contains oxidants complicating further the use of oxidant biomarkers. One of the most widely used oxidant markers in asthma is exhaled nitric oxide (NO), which plays an important role in the pathogenesis of asthma and disease monitoring. Another oxidant marker that has been widely investigated in COPD is 8-isoprostane, but it is probably not capable of differentiating asthma from COPD, or even sensitive in the early assessment of these diseases. None of the current biomarkers have been shown to be better than exhaled NO in asthma. There is a need to identify new biomarkers for obstructive airway diseases, especially their differential diagnosis. A comprehensive evaluation of oxidant markers and their combinations will be presented in this review. In brief, it seems that additional analyses utilizing powerful tools such as genomics, metabolomics, lipidomics, and proteomics will be required to improve the specificity and sensitivity of the next generation of biomarkers.

Factors associated with poor asthma control in children aged five to 13 years

BACKGROUND

Most children with asthma should be able to achieve acceptable control. However, are there differences between those with acceptable and poor control, and if so, how can health care approaches be modified accordingly?

OBJECTIVE

To examine the characteristics of elementary school children aged five to 13 years with acceptable and poor levels of asthma control.

METHODS

The present cross-sectional study of children with asthma used five indicators of control, as outlined by the Canadian Asthma Consensus Report, to categorize acceptable and poor asthma control.

RESULTS

Of 153 children, 115 (75%) were rated as having poorly controlled asthma. Of those with poor control, 65 (64%) children were currently using inhaled corticosteroids, and 65% of those reported using inhaled corticosteroids daily versus as needed. Fifty-one per cent of the children with poorly controlled asthma had exposure to tobacco smoke, whereas 79% of the children with asthma under acceptable control were from households with no smokers (P=0.002). The poor control group also had significantly worse parental perceptions of the psychosocial impact of asthma on their child. No significant difference was found in the percentage of those who had written action plans in the poor control group (28%) compared with the acceptable control group (26%), and similar percentages in each group stated that they used the plans.

CONCLUSIONS

Despite the high use of inhaled corticosteroids, the majority of children had poorly controlled asthma. The poor control group had more exposure to tobacco smoke and a worse psychosocial impact due to asthma. Few children had past asthma education and action plans, suggesting that there is a need to improve access to and tools for education.

Occupational asthma

Substantial epidemiologic and clinical evidence indicates that agents inhaled at work can induce asthma. In industrialized countries, occupational factors have been implicated in 9 to 15% of all cases of adult asthma. Work-related asthma includes (1) immunologic occupational asthma (OA), characterized by a latency period before the onset of symptoms; (2) nonimmunologic OA, which occurs after single or multiple exposures to high concentrations of irritant materials; (3) work-aggravated asthma, which is preexisting or concurrent asthma exacerbated by workplace exposures; and (4) variant syndromes. Assessment of the work environment has improved, making it possible to measure concentrations of several high- and low-molecular-weight agents in the workplace. The identification of host factors, polymorphisms, and candidate genes associated with OA is in progress and may improve our understanding of mechanisms involved in OA. A reliable diagnosis of OA should be confirmed by objective testing early after its onset. Removal of the worker from exposure to the causal agent and treatment with inhaled glucocorticoids lead to a better outcome. Finally, strategies for preventing OA should be implemented and their cost-effectiveness examined.