Definitions of emphysema, chronic bronchitis, asthma, and airflow obstruction: 25 years on from the Ciba symposium

Developing Interventions for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an incurable, progressive respiratory disease that may have a significant negative impact on the morbidity and mortality of affected patients. A substantial portion of the world's population is affected by COPD, and despite optimal medical management with medications, supplemental oxygen, and pulmonary rehabilitation, many patients are left debilitated because of this disease. Bronchoscopic treatment modalities offer a less-invasive method for the treatment of refractory COPD compared to surgical interventions and have expanded the potential therapeutic options for these patients. Bronchoscopic lung volume reduction is aimed at decreasing the hyperinflation and air trapping that occur in emphysema, and the most studied and successful intervention is endobronchial valve placement. Endobronchial coils, polymeric sealants, and thermal ablation are other researched alternatives. Additional interventional procedures are being investigated for the treatment of the mucus hypersecretion and cough that are associated with the chronic bronchitis phenotype of COPD and include targeted lung denervation, metered dose spray cryotherapy, deobstruction balloon, and bronchial rheoplasty. This review summarizes the most recent evidence pertaining to available therapies for the management of COPD, including chronic bronchitis, with a particular focus on bronchoscopic interventions.

Patients' acceptance of outcome and experience measurements during hospitalisation for COPD exacerbations: a CICERO Clinical Research Collaboration-European Lung Foundation online patient survey

Background

The lack of standardised outcome assessments during hospitalisation and follow-up for acute COPD exacerbations has hampered scientific progress and clinical proficiency. The objective of the present study was to evaluate patients' acceptance of selected outcome and experience measurements during hospitalisations for COPD exacerbations and follow-up.

Methods

An online survey was held amongst COPD patients in France, Belgium, The Netherlands, Germany and the UK. The European Lung Foundation COPD Patient Advisory Group was involved in the conceptualisation, development and dissemination of the survey. The survey was complementary to a previously obtained expert consensus. We assessed patients' views and acceptance of selected patient-reported outcomes or experiences and corresponding measurement instruments (for dyspnoea, frequent productive cough, health status and hospitalisation experience), and of selected clinical investigations (blood draw, pulmonary function test, 6-min walk test, chest computed tomography, echocardiography).

Findings

200 patients completed the survey. All selected outcomes and experiences were deemed important, and acceptance of their methods of assessment was high. The modified Medical Research Council scale and a numerical rating scale to address dyspnoea, the COPD Assessment Test for quality of life and frequent productive cough, and the Hospital Consumer Assessment of Healthcare Providers and Systems for hospital experiences were the instruments preferred by patients. Consensus on importance of blood draw and spirometry was higher compared with the other investigations.

Interpretation

The survey results endorse the use of the selected outcome and experience measurements during hospitalisations for COPD exacerbations. They can be used to optimise standardised and patient-centred care and facilitate multicentric data collection.

Benralizumab Effectiveness in Severe Eosinophilic Asthma with Co-Presence of Bronchiectasis: A Real-World Multicentre Observational Study

Introduction: The co-presence of bronchiectasis (BE) in severe eosinophilic asthma (SEA) is common. Data about the effectiveness of benralizumab in patients with SEA and BE (SEA + BE) are lacking. Aim: The aim of this study was to evaluate the effectiveness of benralizumab and remission rates in patients with SEA compared to SEA + BE, also according to BE severity. Methods: We conducted a multicentre observational study, including patients with SEA who underwent chest high-resolution computed tomography at baseline. The Bronchiectasis Severity Index (BSI) was used to assess BE severity. Clinical and functional characteristics were collected at baseline and after 6 and 12 months of treatment. Results: We included 74 patients with SEA treated with benralizumab, of which 35 (47.2%) showed the co-presence of bronchiectasis (SEA + BE) with a median BSI of 9 (7-11). Overall, benralizumab significantly improved the annual exacerbation rate (p < 0.0001), oral corticosteroids (OCS) consumption (p < 0.0001) and lung function (p < 0.01). After 12 months, significant differences were found between SEA and SEA + BE cohorts in the number of exacerbation-free patients [64.1% vs. 20%, OR 0.14 (95% CI 0.05-0.40), p < 0.0001], the proportion of OCS withdrawal [-92.6% vs. -48.6, p = 0.0003], and the daily dose of OCS [-5 mg (0 to -12.5) vs. -12.5 mg (-7.5 to -20), p = 0.0112]. Remission (zero exacerbations + zero OCS) was achieved more frequently in the SEA cohort [66.7% vs. 14.3%, OR 0.08 (95% CI 0.03-0.27), p < 0.0001]. Changes in FEV₁% and FEF_25-75% were inversely correlated with BSI (r = -0.36, p = 0.0448 and r = -0.41, p = 0.0191, respectively). Conclusions: These data suggest that benralizumab exerts beneficial effects in SEA with or without BE, although the former achieved less OCS sparing and fewer respiratory-function improvements.

Mucus Plugs Persist in Asthma, and Changes in Mucus Plugs Associate with Changes in Airflow over Time

Rationale: Cross-sectional analysis of mucus plugs in computed tomography (CT) lung scans in the Severe Asthma Research Program (SARP)-3 showed a high mucus plug phenotype. Objectives: To determine if mucus plugs are a persistent asthma phenotype and if changes in mucus plugs over time associate with changes in lung function. Methods: In a longitudinal analysis of baseline and Year 3 CT lung scans in SARP-3 participants, radiologists generated mucus plug scores to assess mucus plug persistence over time. Changes in mucus plug score were analyzed in relation to changes in lung function and CT air trapping measures. Measurements and Main Results: In 164 participants, the mean (range) mucus plug score was similar at baseline and Year 3 (3.4 [0-20] vs. 3.8 [0-20]). Participants and bronchopulmonary segments with a baseline plug were more likely to have plugs at Year 3 than those without baseline plugs (risk ratio, 2.8; 95% confidence interval [CI], 2.0-4.1; P < 0.001; and risk ratio, 5.0; 95% CI, 4.5-5.6; P < 0.001, respectively). The change in mucus plug score from baseline to Year 3 was significantly negatively correlated with change in FEV1% predicted (rp = -0.35; P < 0.001) and with changes in CT air trapping measures (all P values < 0.05). Conclusions: Mucus plugs identify a persistent asthma phenotype, and susceptibility to mucus plugs occurs at the subject and the bronchopulmonary segment level. The association between change in mucus plug score and change in airflow over time supports a causal role for mucus plugs in mechanisms of airflow obstruction in asthma.

Asthma and COPD versus phenotypic traits: Toward precision medicine in chronic airway disease

BACKGROUND

Asthma and COPD diagnoses are used to classify chronic airway diseases; however, both diseases are related to phenotypic traits like allergy, obesity, cough, sputum production, low-grade inflammation, smoking, elevated blood eosinophil count, comorbidities, and occupational exposures. Whether such traits can replace asthma and COPD diagnoses when assessing risk of exacerbation is unclear. We tested the hypothesis that individuals with either asthma or COPD diagnoses have similar risk of moderate and severe exacerbations when adjusted for differences in phenotypic traits.

METHODS

From the Copenhagen General Population Study, a cohort study of the general population, we included 7190 individuals with chronic airway disease. Phenotypic traits were recorded at baseline and risk of exacerbations was assessed during follow-up from 2003 to 2013.

RESULTS

The incidence rate ratio (IRR) of moderate exacerbations in individuals with clinical COPD was 1.61 (95% Confidence Interval, 1.27-2.02) compared to individuals with asthma in a model only adjusted for age, sex, and education, but after the inclusion of phenotypic traits IRR was 1.05 (0.82-1.35). Corresponding IRRs of severe exacerbations in individuals with clinical COPD versus asthma were 3.82 (2.73-5.35) and 2.28 (1.63-3.20), respectively.

CONCLUSIONS

When taking phenotypic traits into account, individuals with asthma and COPD had comparable risk of moderate exacerbations; however, corresponding risk of severe exacerbations was higher in individuals with COPD than in those with asthma.

Mepolizumab effectiveness in patients with severe eosinophilic asthma and co-presence of bronchiectasis: A real-world retrospective pilot study

BACKGROUND

The association of bronchiectasis (BE) in patients with severe eosinophilic asthma (SEA) is quite frequent. Mepolizumab is a well-recognized treatment for SEA; we aim to evaluate its effectiveness in SEA patients with and without BE in real-life.

METHODS

We performed a single-center retrospective pilot study, including patients with SEA treated with mepolizumab for one year. Asthma control test (ACT), lung function, annual exacerbations rate, oral corticosteroid dosage, FeNO, chronic mucous secretions, blood and sputum eosinophils were recorded at baseline and after 6 and 12 months.

RESULTS

we included 32 patients (mean age: 52.3 ± 10, 59% female). 50% showed co-presence of bronchiectasis, (SEA + BE). Significant improvements were found in ACT [(13.8 ± 4.6 to 20.7 ± 4.1, p = 0.0009) and (13 ± 4.8 to 20.7 ± 4.6, p = 0.0003)], annual exacerbations rate [from 7 (4-12) to 0 (0.00-0.75) and from 8 (4-12) to 0 (0-1), p < 0.0001], and blood eosinophils count [748 cells/μL (400-1250) vs. 84 cells/μL (52.5-100), and from 691 cells/μL (405-798) vs. 60 cells/μL (41-105), p < 0.0001] in SEA and SEA + BE group respectively, already after 6 months of treatment. A reduction in daily oral corticosteroids intake at 12 months was shown [from 15 mg (0-25) to 0 mg (0-0), p = 0.003 and from 8.8 mg (0-25) to 0 mg (0-0) (p = 0.01)] in both SEA and SEA + BE, respectively. Similar results were found, comparing SEA + BE patients based on the severity of bronchiectasis.

CONCLUSIONS

Mepolizumab effectively improves asthma symptoms control, reducing annual exacerbations and corticosteroid intake in all patients with SEA, even in the subgroup with coexisting bronchiectasis, independently of their severity.

Defining Chronic Mucus Hypersecretion Using the CAT in the SPIROMICS Cohort

Background

Chronic cough and phlegm are frequently reported chronic obstructive pulmonary disease (COPD) symptoms. Prior research classified chronic mucus hypersecretion (CMH) based on the presence of these symptoms for ≥3 months, called chronic bronchitis (CB) if respiratory infection symptoms were present for 1–2 years (Medical Research Council [MRC] definition). We explored whether the COPD Assessment Test (CAT), a simple measure developed for routine clinical use, captures CMH populations and outcomes similarly to MRC and St. George’s Respiratory Questionnaire (SGRQ) definitions.

Methods

We identified CMH in the SPIROMICS COPD cohort using (a) MRC definitions, (b) SGRQ questions for cough and phlegm (both as most/several days a week), and (c) CAT cough and phlegm questions. We determined optimal cut-points for CAT items and described exacerbation frequencies for different CMH definitions. Moderate exacerbations required a new prescription for antibiotics/oral corticosteroids or emergency department visit; severe exacerbations required hospitalization. Results were stratified by smoking status.

Results

In a population of 1431 participants (57% male; mean FEV₁% predicted 61%), 47% and 49% of evaluable participants had SGRQ- or CAT-defined CMH, respectively. A cut-point of ≥2 for cough and phlegm items defined CMH in CAT. Among SGRQ-CMH+ participants, 80% were also defined as CMH+ by the CAT. CMH+ participants were more likely to be current smokers. A higher exacerbation frequency was observed for presence of CMH+ versus CMH− in the year prior to baseline for all CMH definitions; this trend continued across 3 years of follow-up, regardless of smoking status.

Conclusion

Items from the CAT identified SGRQ-defined CMH, a frequent COPD trait that correlated with exacerbation frequency. The CAT is a short, simple questionnaire and a potentially valuable tool for telemedicine or real-world trials. CAT-based CMH is a novel approach for identifying clinically important characteristics in COPD that can be ascertained in these settings.

Defining severe obstructive lung disease in the biologic era: an endotype-based approach

Severe obstructive lung disease, which encompasses asthma, chronic obstructive pulmonary disease (COPD) or features of both, remains a considerable global health problem and burden on healthcare resources. However, the clinical definitions of severe asthma and COPD do not reflect the heterogeneity within these diagnoses or the potential for overlap between them, which may lead to inappropriate treatment decisions. Furthermore, most studies exclude patients with diagnoses of both asthma and COPD. Clinical definitions can influence clinical trial design and are both influenced by, and influence, regulatory indications and treatment recommendations. Therefore, to ensure its relevance in the era of targeted biologic therapies, the definition of severe obstructive lung disease must be updated so that it includes all patients who could benefit from novel treatments and for whom associated costs are justified. Here, we review evolving clinical definitions of severe obstructive lung disease and evaluate how these have influenced trial design by summarising eligibility criteria and primary outcomes of phase III randomised controlled trials of biologic therapies. Based on our findings, we discuss the advantages of a phenotype- and endotype-based approach to select appropriate populations for future trials that may influence regulatory approvals and clinical practice, allowing targeted biologic therapies to benefit a greater proportion and range of patients. This calls for co-ordinated efforts between investigators, pharmaceutical developers and regulators to ensure biologic therapies reach their full potential in the management of severe obstructive lung disease.

Frequency and effect of type 1 hypersensitivity in patients from India with chronic obstructive pulmonary disease and associated upper airways symptoms

Background

Chronic obstructive pulmonary disease (COPD) is now recognized as a systemic disorder with many comorbidities. Atopy in patients with COPD and upper airways symptoms has not been characterized.

Objective

We investigated the occurrence and impact of aeroallergen sensitisation in patients with COPD and upper airways symptoms.

Methods

All 41 subjects with COPD diagnosed as per Global Initiative for Chronic Obstructive Lung Disease guidelines, underwent spirometry with reversibility, computed tomography of the paranasal sinuses (CT-PNS), skin prick test (SPT) against common aeroallergens and responded to St. George's Respiratory Questionnaire (SGRQ) and Sino Nasal Outcome Test - 22 (SNOT-22) questionnaires. Upper airways symptoms were assessed as per the Allergic Rhinitis and its Impact on Asthma guidelines.

Results

As documented earlier, 27 of the 41 patients (65.9%) with COPD had upper airways symptoms. Of these 27 patients, 11 had SPT positivity against at least one aeroallergen (group 1). One patient had monosensitisation to pollens of grass Imperata while polysensitisation was seen in 10/11 patients commonly to weeds, trees, and insects. Fungal sensitisation to Aspergillus fumigatus was seen in 3 of 11 patients (27.2%). In group 1, all 11 patients (100%) had radiological sinusitis as compared to 8 of 16 (50%) in group 2. The mean CT-PNS scores were significantly higher in group 1 as compared to group 2. Similarly, the SNOT-22 scores were significantly higher in group 1 as compared to group 2. However, there was no difference in SGRQ scores between the 2 groups. In group 1, there was a significant correlation between CT-PNS and SNOT-22 scores.

Conclusion

Patients with COPD, associated upper airways symptoms and a positive SPT had a significantly higher frequency of radiological sinusitis on CT-PNS. They even had worse quality of life as compared to those with a negative SPT. The study suggested that atopic patients with COPD and upper airways involvement were more symptomatic. It is therefore possible that upper airways symptoms, if left untreated, would result in less than desirable control of the disease.

Identifying possible asthma-COPD overlap syndrome in patients with a new diagnosis of COPD in primary care

The asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) remains poorly characterised. Our aim was to describe an algorithm for identifying possible ACOS in adults with newly diagnosed COPD in primary care. General practitioners (n=241) consecutively recruited subjects ⩾35 years, with tobacco exposure, at least one respiratory symptom and no previous diagnosis of obstructive lung disease. Possible ACOS was defined as chronic airflow obstruction, i.e., post-bronchodilator (BD) forced expiratory volume 1/forced vital capacity (FEV₁/FVC) ratio<0.70, combined with wheeze (ACOS wheeze) and/or significant BD reversibility (ACOS BD reversibility). Of 3,875 (50% females, mean age 57 years) subjects screened, 700 (18.1%) were diagnosed with COPD, i.e., symptom(s), tobacco exposure and chronic airflow obstruction. Indications for ACOS were found in 264 (38%) of the COPD patients. The prevalence of ACOS wheeze and ACOS BD reversibility was 27% (n=190) and 16% (n=113), respectively (P<0.001), and only 6% (n=39) of the COPD patients fulfilled both criteria for ACOS. Patients with any ACOS were younger (P=0.04), had more dyspnoea (P<0.001), lower FEV₁%pred (67% vs. 74%; P<0.001) and lower FEV₁/FVC ratio (P=0.001) compared with COPD-only patients. Comparing subjects fulfilling both criteria for ACOS with those fulfilling criteria for ACOS wheeze only (n=151) and those fulfilling criteria for ACOS BD reversibility only (n=74) revealed no significant differences. Irrespective of the applied ACOS definition, no significant difference in life-time tobacco exposure was found between ACOS- and COPD-only patients. In subjects with a new diagnosis of COPD, the prevalence of ACOS is high. When screening for COPD in general practice among patients with no previous diagnosis of obstructive lung disease, patients with possible ACOS may be identified by self-reported wheeze and/or BD reversibility.

Understanding the pathophysiology of the asthma-chronic obstructive pulmonary disease overlap syndrome

PURPOSE OF REVIEW

The review will provide an update on the pathophysiology and studies of inflammation associated with the asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) and the mechanism(s) responsible for persistent expiratory airflow limitation in never-smoked asthma patients who develop loss of lung elastic recoil consistent with an asthma-COPD clinical phenotype (ACOS in nonsmokers).

RECENT FINDINGS

Patients with a clinical diagnosis of ACOS have more frequent respiratory exacerbations and hospitalizations than COPD patients without ACOS. ACOS patients should be treated with inhaled corticosteroids, short and long-acting β2-agonist, and long-acting muscarinic receptor antagonist. Biomarker work suggests that a molecular phenotype of ACOS (e.g., elevated markers of eosinophilic or type 2 inflammation) incompletely corresponds to clinical phenotypes. Recently, we reported sentinel observation of unsuspected mild diffuse centrilobular emphysema in never-smoked asthma patients at autopsy, despite mild changes in lung computed tomography and normal diffusing capacity.

SUMMARY

Recent studies have shown that subgroups of COPD and asthma patients may have overlapping immune responses. Never-smoked asthma patients may have persistent expiratory airflow limitation because of loss of lung elastic recoil. This may be because of unsuspected centrilobular emphysema detected at autopsy, and not easily diagnosed on lung computed tomography and diffusing capacity.

Long-term prognosis of asthma, chronic obstructive pulmonary disease, and asthma-chronic obstructive pulmonary disease overlap in the Copenhagen City Heart study: a prospective population-based analysis

BACKGROUND

Long-term prognosis of patients with characteristics of both chronic obstructive pulmonary disease (COPD) and asthma, named asthma-COPD overlap, is poorly described. We investigated the long-term prognosis of individuals with different types of chronic airway disease, with a special focus on individuals with asthma-COPD overlap.

METHODS

We assigned participants from the Copenhagen City Heart Study into six subgroups: healthy never-smokers, ever-smokers without asthma and COPD, those with asthma with low cumulated smoking exposure and no airflow limitation, those with COPD, those with asthma-COPD overlap with asthma onset before the age of 40 years, and those with asthma-COPD overlap with asthma onset after the age of 40 years. We defined asthma-COPD overlap as current self-reported asthma and a postbronchodilatatory forced expiratory volume in 1 s (FEV1) to forced vital capacity ratio of less than 0·7, without any restrictions regarding smoking. We investigated the course of FEV1 decline for 18 years and risk of admission to hospital due to exacerbations or pneumonias and respiratory and all-cause mortality for 22 years. We analysed FEV1 decline in the six groups using a linear mixed-effects model.

FINDINGS

We included 8382 participants from the Copenhagen City Heart Study in our study: 2199 never-smokers, 5435 ever-smokers, 158 with asthma, 320 with COPD, 68 with asthma-COPD overlap with early-onset asthma, and 202 with asthma-COPD overlap with late-onset asthma. The multivariable-adjusted decline in FEV1 in asthma-COPD overlap with early-onset asthma was 27·3 mL (standard error 5·0) per year, which did not differ significantly from the decline of 20·9 mL (1·2) per year in healthy never-smokers (p=0·19). FEV1 decline in individuals with asthma-COPD overlap with late-onset asthma was 49·6 mL (3·0) per year, higher than the decline in asthma-COPD overlap with early-onset asthma (p=0·0001), the decline of 39·5 mL (2·5) per year in COPD (p=0·003), and the decline in healthy never-smokers (p<0·0001). Hazard ratios for hospital admissions due to exacerbations of asthma or COPD were 39·48 (95% CI 25·93-60·11) in asthma-COPD overlap with early-onset asthma, 83·47 (61·67-112·98) in asthma-COPD overlap with late-onset asthma, 23·80 (17·43-33·50) in COPD, and 14·74 (10·06-21·59) in asthma compared with never-smokers without lung disease (all p<0·0001). Life expectancy was 9·3 years (5·4-13·1) shorter in participants with asthma-COPD overlap with early-onset asthma, 12·8 years (11·1-14·6) shorter in those with asthma-COPD overlap with late-onset asthma, 10·1 years (8·6-11·5) shorter in those with COPD (all p<0·0001), and 3·3 years (1·0-5·5) shorter in those with asthma (p=0·004) than in healthy never-smokers.

INTERPRETATION

Prognosis of individuals with asthma-COPD overlap is poor and seems to be affected by the age of recognition of asthma, being worst in those with late asthma onset (after 40 years of age). Such patients should be followed up closely to prevent fast lung function decline and exacerbations.

FUNDING

Capital Region of Copenhagen, Danish Heart Foundation, Danish Lung Foundation, Velux Foundation, AstraZeneca.

Revisiting the Dutch hypothesis

The Dutch hypothesis was first articulated in 1961, when many novel and advanced scientific techniques were not available, such as genomics techniques for pinpointing genes, gene expression, lipid and protein profiles, and the microbiome. In addition, computed tomographic scans and advanced analysis techniques to dissect (small) airways disease and emphysema were not available. At that time, the group of researchers under the visionary guidance of Professor N. G. M. Orie put forward that both genetic and environmental factors can determine whether one would have airway obstructive diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Moreover, they stipulated that the phenotype of obstructive airway disease could be affected by sex and changes with aging. Orie and colleagues' call to carefully phenotype patients with obstructive airways diseases has been adopted by many current researchers in an attempt to determine the heterogeneity of both asthma and COPD to better define these diseases and optimize their treatment. The founders of the Dutch hypothesis were far ahead of their time, and we can learn from their insights. We should fully characterize all patients in our clinical practice and not just state that they have asthma, COPD, or asthma and COPD overlap syndrome. This detailed phenotyping can help in understanding these obstructive airway diseases and provide guidance for disease management.

[From COPD definitions to COPD phenotypes]

COPD is characterized by incompletely reversible airflow limitation (FEV1/FVC < 70%). The historical classification of COPD, which was based on the severity of airflow limitation assessed by the level of FEV1, did not take into account the various aspects of COPD patients. At comparable levels of FEV1, COPD patients show marked heterogeneity in clinical manifestations (dyspnea, rates of exacerbations, exercise capacity, and quality of life), leading to the proposal of the current COPD classification based not only on FEV1, but also on symptoms (dyspnea or quality of life) and history of exacerbations. Limitations of this novel classification of COPD include its relative complexity and the absence of age and comorbidities. Recent identification of clinical COPD phenotypes (i.e., subgroups of COPD patients sharing not only clinical characteristics, but also natural history and/response to therapy) could result in progresses in the pathophysiology of the disease, in the development of specific biomarkers, and could facilitate evaluation of drugs in clinical trials. The development of simple algorithms, using easily available clinical data, will allow identification of phenotypes in clinical practice and may lead to individualized therapies.

[Influence of tobacco smoking on the risk of developing asthma]

The aim of this general review is to investigate the influence of active and passive smoking on the development of asthma in children and adults. Passive smoking during and after pregnancy facilitates the onset of childhood asthma and wheezing. In particular, smoking during pregnancy is associated with the occurrence of wheezing prior to the age of 4 years. In contrast, the results of studies on the relationship between parental smoking in the post-natal period and the onset of asthma or wheezing are discordant. Exposure to passive smoking during childhood facilitates the occurrence of asthma in adulthood. In adults and adolescents, active smoking appears to be a factor favoring the development of asthma. On the other hand, non-smoking adult subjects without history of asthma exposed to passive smoking have a risk of asthma. The pathophysiological mechanisms by which tobacco smoke is the cause of asthma are still poorly known. Smoking cessation is an essential component in the management of asthmatic subjects who smoke, facilitating the control of the disease.

Association between obesity and asthma in the elderly population: potential roles of abdominal subcutaneous adiposity and sarcopenia

BACKGROUND

Obesity is a significant risk factor for asthma; however, the association of asthma with obesity has rarely been studied in the elderly population. The role of central obesity has been suggested as a link between the 2 entities but has not been comprehensively studied in elderly populations.

OBJECTIVE

To investigate the mechanisms of association between obesity and asthma in the elderly population.

METHODS

This cross-sectional analysis included 994 participants (aged ≥65 years) in the Korean Longitudinal Study on Health and Aging. Asthma was defined by using questionnaires. Spirometry and chest radiography were performed to exclude asthma-mimicking conditions. Measurements of abdominal subcutaneous and visceral fat were calculated by computed tomography of the abdomen, and regional body compositions were measured by dual energy X-ray absorptiometry. Biochemical parameters were also measured.

RESULTS

The prevalence of asthma was 5.4%. The study population had a mean body mass index (BMI) of 24.0. Multivariate logistic regression tests revealed that the risk of asthma increased in proportion to an increase in BMI or abdominal subcutaneous adiposity. However, no association was found with visceral adiposity, serum adiponectin levels, or serum vitamin D levels. The dual energy X-ray absorptiometry-measured appendicular fat-free mass index was inversely related to asthma among patients with a BMI of 25.0 or greater.

CONCLUSION

Our findings suggest that the relationships between obesity and asthma in the elderly population may be mediated by factors such as abdominal subcutaneous adiposity and sarcopenia. These associations warrant further investigations to identify their potential roles.

Oxygen-enhanced MRI vs. quantitatively assessed thin-section CT: pulmonary functional loss assessment and clinical stage classification of asthmatics

PURPOSE

The purpose of this study was to prospectively compare the efficacy of oxygen-enhanced MR imaging (O(2)-enhanced MRI) and CT for pulmonary functional loss assessment and clinical stage classification of asthmatics.

MATERIALS AND METHODS

O(2)-enhanced MRI, CT and %FEV(1) measurement were used 34 consecutive asthmatics classified into four stages ('Mild Intermittent [n=7]', 'Mild Persistent [n=8], 'Moderate Persistent [n=14]' and 'Severe Persistent [n=5]'). Relative enhancement ratio maps for every subject were generated, and determine mean relative enhancement ratios (MRERs). Mean lung density (MLD) and the airway wall area (WA) corrected by body surface area (WA/BSA) were also measured on CT. To compare the efficacy of the two methods for pulmonary functional loss assessment, all indexes were correlated with %FEV(1). To determine the efficacy of the two methods for clinical stage classification, all parameters for the four clinical stages were statistically compared.

RESULTS

%FEV(1) showed fair or moderate correlation with all parameters (0.15≤r(2)≤0.30, p<0.05). WA, WA/BSA and MRER of the 'Severe Persistent' group were significantly larger than those of 'Mild Intermittent' and 'Mild Persistent' groups (p<0.05), and MRER of the 'Moderate Persistent' group significantly lower than that of the 'Mild Intermittent' group (p<0.05).

CONCLUSION

O(2)-enhanced MRI is as effective as CT for pulmonary functional loss assessment and clinical stage classification of asthmatics.

Role of mucolytics in the management of COPD

There is, to date, no medical therapy that modifies the decline in lung function that occurs in COPD. As the disease becomes more severe, exacerbations of COPD become increasingly common, affecting patient quality of life and increasing health care costs. Mucolytic agents, through their actions on inflammatory and oxidative pathways, have potential benefits in COPD. This paper reviews the randomized controlled trial (RCT) evidence for the effectiveness of at least 2 months of daily therapy with oral mucolytics in COPD. Based on evidence from 26 RCTs, mucolytics reduce exacerbations by up to 0.8 exacerbations per year, with a greater effect in patients with more severe COPD. This effect appears to be of a similar magnitude to the reduction in exacerbations seen with tiotropium and inhaled corticosteroids (ICS), but RCTs that compared the agents would be required to confirm this. Mucolytics do not affect the rate of lung function decline, but they do not have any significant adverse effects. Mucolytic treatment should be considered in: patients with more severe COPD who have frequent or prolonged exacerbations; those who are repeatedly admitted to hospital; or in those patients with frequent exacerbations who are unable to take tiotropium or ICS.

What have we learned from large drug treatment trials in COPD?

Although the development of effective treatments for patients with chronic obstructive pulmonary disease (COPD) has not been seen as a high priority, the past decade has seen a substantial increase in the number of clinical studies examining different treatments for this disease. Large studies are needed to adequately assess the effectiveness of treatment because of the chronic nature of the disease and the intermittent occurrence of some key outcomes such as exacerbations. Data from randomised controlled trials show that treatment improves exercise performance by increasing lung volume rather than changing expiratory flow. Although assessment of lung function remains the cornerstone of drug assessment, improvements in health status, the number of exacerbations and admissions to hospital are now recognised as important treatment outcomes. Randomised controlled trial data provide the best evidence for treatment efficacy, but results of these studies can be affected by differences in inclusion criteria and patient dropout during the study. Bronchodilator reversibility testing does not reliably define subgroups that will respond to a particular treatment. Carefully done and adequately powered clinical trials continue to inform, not only our views about treatment, but also our understanding of COPD and how it is best assessed and managed. Ensuring that these expensive studies are done objectively to the highest standard is an important goal for the next decade.

The role of airway secretions in COPD: pathophysiology, epidemiology and pharmacotherapeutic options

Often considered an aggravating but otherwise benign component of chronic obstructive pulmonary disease (COPD), airway mucus hypersecretion is now recognised as a potential risk factor for an accelerated loss of lung function in COPD and is a key pathophysiological feature in many patients, particularly those prone to respiratory tract infection. Consequently, it is important to develop drugs that inhibit mucus hypersecretion in these susceptible patients. Conventional therapy including anticholinergics, beta2-adrenoceoptor agonists, alone or in combination with corticosteroids, mucolytics and macrolide antibiotics are not entirely or consistently effective in inhibiting airway mucus hypersecretion in COPD. Novel pharmacotherapeutic targets are being investigated, including inhibitors of nerve activity (e.g., BK(Ca) channel activators), tachykinin receptor antagonists, epoxygenase inducers (e.g., benzafibrate), inhibitors of mucin exocytosis (e.g., anti-MARCKS peptide and Munc-18B blockers), inhibitors of mucin synthesis and goblet cell hyperplasia (e.g., EGF receptor tyrosine kinase inhibitors, p38 MAP kinase inhibitors, MEK/ERK inhibitors, hCACL2 blockers and retinoic acid receptor-alpha antagonists), inducers of goblet cell apoptosis (e.g., Bax inducers or Bcl-2 inhibitors), and purinoceptor P(2Y2) antagonists to inhibit mucin secretion or P(2Y2) agonists to hydrate secretions. However, real and theoretical differences delineate the mucus hypersecretory phenotype in COPD from that in other hypersecretory diseases of the airways. More information is required on these differences to identify therapeutic targets pertinent to COPD which, in turn, should lead to rational design of anti-hypersecretory drugs for specific treatment of airway mucus hypersecretion in COPD.

Knowledge about asthma and COPD: associations with sick leave, health complaints, functional limitations, adaptation, and perceived control

We sought to investigate associations between knowledge about the disease and sick leave, health complaints, functional limitations, adaptation and perceived control. Patients with asthma (n = 101) and COPD (n = 64) underwent lung function tests and completed questionnaires. In addition, all were asked the question: 'what is the diagnosis of your disease?', with the response categories: 'asthma' and 'COPD (chronic bronchitis or emphysema)'. Thirty-five percent of the asthma patients and 30% of the COPD patients did not know their correct diagnosis. Sick leave was not associated with knowledge about the disease in asthma and COPD. In asthma, much knowledge about management of the disease was associated with better adaptation (P = 0.01) and less perceived control over health by external factors (P = 0.02). Knowing the correct diagnosis was associated with less control over health by powerful others (P = 0.02). For COPD, more knowledge about management of the disease was associated with better adaptation (P = 0.02) and less control over health by internal factors (P = 0.01). Knowing the correct diagnosis was associated with less control over dyspnea at work (P = 0.01).

Chronic bronchitis, cigarette smoking, and the subsequent onset of depression and anxiety: results from a prospective population-based cohort study

OBJECTIVE

The authors used data from a prospective, population-based cohort study to examine: (a) whether the presence of chronic bronchitis predicts the subsequent onset of depression or anxiety, and (b) if the incidence of depressed or anxious cases was different for smokers compared with nonsmokers.

MATERIALS AND METHODS

For studying the relation between chronic bronchitis and anxiety or depression, we used data from respectively 4468 and 4520 respondents.

RESULTS

The number of incident anxious (19.1%, n = 17) and depressed (14.0%, n = 13) cases was highest in employees with chronic bronchitis compared with employees without respiratory complaints (4.3%, n = 189 and 3.3%, n = 145, respectively). The presence of chronic bronchitis was associated with a significant increase in anxious and depressed cases (odds ratio (OR) for anxiety = 5.09, 95% confidence interval (CI) 2.91, 8.89; OR for depression = 4.38, 95% CI 2.35, 8.16). The incidence of anxiety as well as depression was strongest in the smokers group (OR for anxiety = 8.94, 95% CI 4.08, 19.59; OR for depression = 7.56, 95% CI 3.37, 16.96).

CONCLUSIONS

This prospective study shows significantly higher levels of anxiety as well as depression in employees with chronic bronchitis. Results also seem to indicate that smoking cigarettes modifies this association, resulting in an increased risk of depression and anxiety in employees with chronic bronchitis who smoke.

Risk of depression and anxiety in employees with chronic bronchitis: the modifying effect of cigarette smoking

OBJECTIVE

The present study evaluates whether smoking status modifies the association between chronic bronchitis and depression or anxiety in a population-based sample. Furthermore, we tested whether these associations are different in people without any respiratory complaints and those with asthma.

METHODS

For this study, we used cross-sectional data form the Maastricht Cohort Study, a population-based cohort study among Dutch employees.

RESULTS

In total, 7482 employees completed and returned the questionnaire (92.7%). In employees with chronic bronchitis, the prevalence of depression and anxiety was significantly higher compared with healthy employees and employees with asthma. Results indicate that the odds of having comorbid depression or anxiety for employees with chronic bronchitis compared with healthy employees is highest in current and past smokers, indicating that smoking status modifies this association.

CONCLUSION

Chronic bronchitis is strongly associated with depression and anxiety. Because depression and/or anxiety may not only interfere with an attempt to stop smoking but also contribute significantly to experiencing low quality of life, it is important to consider these disorders and chronic bronchitis as different disease entities. Prospective longitudinal studies are needed to elucidate the mechanisms underlying the association among chronic bronchitis, psychiatric disorders, and cigarette smoking.

Preventing exacerbations of chronic bronchitis and COPD: therapeutic potential of mucolytic agents

It is important to find interventions that will reduce the frequency and severity of exacerbations of COPD, because of their effect on morbidity and healthcare expenditure. A Cochrane systematic review included 23 studies that had evaluated the effects of treatment with mucolytic agents in patients with chronic bronchitis or COPD. Mucolytic treatment was associated with a significant reduction of 0.79 exacerbations per patient per year compared with placebo, a 29% decrease. Patients who received treatment with mucolytic agents were twice as likely to remain exacerbation-free in the study period than if they had received placebo, with six patients needing regular treatment with mucolytic agents for 3-6 months to achieve one less exacerbation over that time. Treatment with mucolytic agents resulted in nearly 7 days less illness per patient per year. How mucolytic agents work is unknown, although they may reduce exacerbations by altering mucus production, antioxidation, or antibacterial or immunostimulatory effects. They do not appear to affect the decline in lung function that occurs in COPD. The treatment appears to be without any adverse effects, apart from the need to take oral medication daily. Cost-effectiveness analysis suggests that the point at which the costs of treatment and non-treatment were equal was 1.2 less exacerbations per year. This is higher than the effect observed in the Cochrane review, suggesting that treating everyone with COPD with mucolytic agents would not be cost effective. Those with more frequent and severe exacerbations appear to have the most to gain.

Matrix metalloproteinases activity in COPD associated with wood smoke

BACKGROUND

Wood smoke (WS) exposure causes COPD with respiratory alterations that are similar to those described for COPD associated with tobacco smoke (TS). The aim of the present study was to analyze the effects of WS on matrix metalloproteinase (MMP) activity and expression.

DESIGN

BAL fluid and macrophages were obtained from patients exposed to WS and TS, and from control subjects. Macrophage elastolytic activity was assayed by radiolabeled elastin degradation. Gelatinolytic activity was measured by zymography in BAL fluid samples. MMP-2, MMP-9, and MMP-12 expression were analyzed by reverse transcription polymerase chain reaction in macrophages from each group.

RESULTS

Macrophage elastolytic activity was increased significantly in WS and TS cells in comparison to control subjects with no differences between WS and TS samples. MMP-2 was identified in all groups as a 72-Kd band (proMMP-2), with the highest activity in the WS samples. MMP-9 was present in its latent and active forms with the highest gelatinolytic activity in the WS group. MMP-2 expression was increased in both groups as well as MMP-12 compared with the control. Two of three subjects studied in each COPD group had a significant increase in MMP-9 expression.

CONCLUSION

These findings demonstrate that WS increases MMP activity and expression that might produce lung damage similar to that observed in COPD associated with TS.

Benefits and risks of pharmacological smoking cessation therapies in chronic obstructive pulmonary disease

Smoking cessation is the most effective way to reduce the risk of developing chronic obstructive pulmonary disease (COPD) or to reduce its progression. However, little is known about the efficacy and safety of different pharmacological smoking cessation therapies used for the treatment of patients with COPD who smoke. The aim of this review was to evaluate the benefits and risks of pharmacological smoking cessation therapies in COPD. We conducted an extensive computer-aided literature search which resulted in the identification of four papers that met the inclusion criteria and contributed to this review. In two studies the efficacy of nicotine polacrilex (nicotine gum) was assessed. In one study, which did not have a control group, the efficacy of nicotine nasal spray was evaluated. The fourth study, a placebo-controlled trial, evaluated the efficacy of bupropion sustained release. The results of these studies indicated that nicotine gum, nicotine nasal spray and bupropion have a good safety profile and seem to increase abstinence rates in smokers with COPD. The incidence and nature of specific adverse effects occurring in patients with COPD seem to be comparable with the adverse effects reported by healthy smokers. However, the efficacy seems to depend on the follow-up period used to define success (i.e. abstinence rates decline with longer follow-up), as well as the intensity and duration of the concomitant psychosocial intervention. This review indicates that for a continuation of the effect of pharmacological smoking cessation therapies, the combination of pharmacotherapy (to reduce craving and withdrawal) and a relapse-prevention programme, in which attention is focused on the behavioural aspects of smoking and smoking cessation, seems to increase abstinence, especially when the psychosocial intervention is prolonged for a longer period. Also, the characteristics of the smokers who are motivated to quit must be taken into account in order to increase the number of successful attempts to quit smoking and prevent relapses. We therefore recommend using a holistic approach in which the possible coexistence of multiple problems (which are known to affect the success of smoking cessation strategies) is integrated.

Pulmonary function abnormality and respiratory tract irritation symptoms in epichlorohydrin-exposed workers in Taiwan

BACKGROUND

Epichlorohydrin (ECH) is a strong irritant of the eyes, respiratory tract, and skin. The aims of this study were to examine the dose-response relationship between observed abnormal pulmonary function tests and respiratory tract irritation symptoms among epichlorohydrin-exposed workers in Taiwan.

METHODS

A total of 167 workers were randomly selected from a resin synthesis factory. Sixty-six air samples were taken to determine ECH concentration in the workplace. Demographic data, work history, smoking status, and respiratory tract irritation symptoms were gathered by a standard self-administered questionnaire. Pulmonary function tests were also performed.

RESULTS

There were 13 of 41 (31.7%) abnormal mean mid-expiratory flow (MMEF) among the high-ECH-exposed workers, 11 of 38 (29%) among the low-ECH-exposed workers, and 4 of 59 (6.8%) among non-ECH-exposed workers. There was a significant linear trend between ECH exposure and the prevalence of small airway abnormalities (P = 0.007) after adjusting for other factors. There was also a significant dose-response relationship of respiratory tract irritation symptoms (cough, phlegm, chest tightness, and dyspnea) among the ECH-exposed workers.

CONCLUSIONS

This study suggests that obstructive lung abnormalities and small airway lung damage are associated with ECH exposure. The study also suggests that exposure to very low concentrations (<0.2 ppm) causes significant higher prevalence of respiratory tract irritation symptoms. Causal inferences from the findings cannot be made from this cross-sectional study and further longitudinal studies are needed to better clarify the nature of the observed associations.

How accurate is the self-reported diagnosis of chronic bronchitis?

BACKGROUND

Although it is defined as cough and sputum production for at least 3 months per year for at least 2 consecutive years, difficulties exist in the use of the term chronic bronchitis for clinical diagnosis. In particular, the relationship between diagnosis and symptoms has been difficult to ascertain.

STUDY OBJECTIVES

To determine, in a large epidemiologic study, the degree to which a new self-reported diagnosis of chronic bronchitis (NCBR) satisfies the symptom criteria for that diagnosis, and to determine the relationship between self-reported physician-confirmed diagnoses and symptom criteria.

METHODS

We analyzed data obtained from the Tucson Epidemiologic Study of Obstructive Lung Diseases. Using responses to standardized respiratory questionnaires administered to 4,034 subjects, those with NCBRs were selected and assessed as to whether they met symptom criteria for that diagnosis. Descriptive statistics pertaining to gender, age, and smoking status were obtained. Furthermore, we determined how often symptom criteria were met among a subset of subjects with physician-confirmed self-reported diagnoses.

RESULTS

Of 481 subjects with NCBRs, only 56 subjects (11.6%) met the required symptom criteria. Men compared with women and current smokers compared with ex-smokers or neversmokers were more likely to meet symptom criteria. Four hundred fifteen of 481 subjects with NCBRs had physician-confirmed self-reported diagnoses. Of these, only 52 subjects (12.5%) met symptom criteria. Within the subgroup of subjects who met symptom criteria, higher percentages were observed in the older age groups, but this was not statistically significant.

CONCLUSION

Only a minority of subjects with NCBRs satisfy the symptom criteria of cough and sputum production for at least 3 months per year for at least 2 consecutive years. This relationship holds true even among those with physician-confirmed self-reported diagnoses.

Mortality of elderly subjects with self-reported asthma in a French cohort, 1991-1996

The objective of this study is to describe the mortality of subjects with self-reported asthma aged 65 and over and to determine risk factors. PAQUID (Personnes Agées QUID) is a prospective cohort of 3777 elderly people, living at home in the South-west of France. The study of subjects with self-reported asthma started at 3 year follow-up by using three epidemiological questions: 'Did you have an attack of wheezing that made you feel short of breath in the last 12 past months?', 'Have you ever had asthma?', 'Did you have at least one asthma attack in the previous 12 months?'. Data on mortality were available at 8-year follow-up. Among the 2348 subjects who responded to these questions, 206 reported symptoms of asthma. Two groups were defined as 'pure asthma' and 'associated asthma' taking into account chronic bronchitis and smoking. Besides a gender difference, there was no statistical difference between those two groups so they were combined in a single group for further analysis. During the 5-year study period, 29.1% of subjects with self-reported asthma vs. 23.8% nonasthmatics died. A Cox model with delayed entry was used to calculate mortality rates. Interaction terms between each of the factors related to mortality and asthmatic status were analyzed to determine risk factors of mortality. Subjects with self-reported asthma had a higher risk of death than nonasthmatics (relative risk (RR): 1.49; 95% confidence interval (CI) 1.1-1.9; p = 0.009). This risk was significant (RR: 1.4; 95% CI: 1.05-1.8; p = 0.02) even after adjustment on morbidity variables. However no specific mortality risk factors were found for subjects with self-reported asthma.

Influence of age and disease severity on high resolution CT lung densitometry in asthma

BACKGROUND

Low attenuation areas (LAA) on computed tomographic (CT) scans have been shown to represent emphysematous changes in patients with chronic obstructive pulmonary disease (COPD). However, the significance of LAA is still controversial in patients with asthma. This study was undertaken to assess the usefulness of lung CT densitometry in the detection of airspace enlargement in association with asthma severity.

METHODS

Forty five asthmatic subjects and 15 non-smoking controls were studied to determine the influence of age, pulmonary function, and asthma severity on mean lung density (MLD) and the relative area of the lung showing attenuation values less than -950 HU (RA(950)) on high resolution CT (HRCT) scans.

RESULTS

In asthmatic patients both MLD and RA(950) correlated with parameters of airflow limitation (%FEV(1), FEV(1)/FVC, %FEF(25-75)) and lung volume (%TLC, %FRC, %RV), but not with lung transfer factor (%TLCO, %TLCO/VA). The results of HRCT lung densitometry also correlated with patient age and severity of asthma.

CONCLUSIONS

Decreased CT lung density in non-smoking asthmatics is related to airflow limitation, hyperinflation and aging, but not with lung transfer factor.

Respiratory symptoms relate to physiological changes and inflammatory markers reflecting central but not peripheral airways. A study in 60-year-old 'healthy' smokers and never-smokers

The aim of this study was to evaluate the relationship between respiratory symptoms, lung function and inflammatory markers in 'healthy' smokers. The study population was recruited from an epidemiological study with subjects of the same age, 60 years. Only smokers who considered themselves healthy (n=58) and a random sample of never-smokers (n=34) were investigated. All subjects underwent lung function tests--spirometry, carbon monoxide transfer (DLco) and the single-breath N2 method (N2 test)--together with high-resolution computed tomography (HRCT). A flexible bronchoscopy with a bronchoalveolar lavage (BAL) was performed in 30 smokers and 18 never-smokers. Bronchial biopsies were also taken. Smokers who reported non-specific respiratory problems, chronic bronchitis and wheezing in a symptom questionnaire had a lower forced expiratory volume in 1 sec (FEV1), FEV% and specific airway conductance (sGaw), lung function tests supposed to reflect the more central airways, than smokers without respiratory symptoms. A limited number of smokers with occasional non-specific respiratory problems also had more cytotoxic T cells (CD8) in bronchial biopsies. No differences were found in DLCO and the N2 test, lung function tests supposed to reflect the more peripheral airways including the alveoli, HRCT-diagnosed emphysema or inflammatory markers in blood and BAL between smokers with and without respiratory symptoms. It is concluded that even when smokers consider themselves 'healthy' they have mild symptoms that are related more to physiological changes and inflammatory markers that may reflect events in the central airways than to changes that may reflect events in the peripheral airways.

Canadian Asthma Consensus Report, 1999. Canadian Asthma Consensus Group

OBJECTIVES

To provide physicians with current guidelines for the diagnosis and optimal management of asthma in children and adults, including pregnant women and the elderly, in office, emergency department, hospital and clinic settings.

OPTIONS

The consensus group considered the roles of education, avoidance of provocative environmental and other factors, diverse pharmacotherapies, delivery devices and emergency and in-hospital management of asthma.

OUTCOMES

Provision of the best control of asthma by confirmation of the diagnosis using objective measures, rapid achievement and maintenance of control and regular follow-up.

EVIDENCE

The key diagnostic and therapeutic recommendations are based on the 1995 Canadian guidelines and a critical review of the literature by small groups before a full meeting of the consensus group. Recommendations are graded according to 5 levels of evidence. Differences of opinion were resolved by consensus following discussion.

VALUES

Respirologists, immunoallergists, pediatricians and emergency and family physicians gave prime consideration to the achievement and maintenance of optimal control of asthma through avoidance of environmental inciters, education of patients and the lowest effective regime of pharmacotherapy to reduce morbidity and mortality.

BENEFITS, HARMS AND COSTS

Adherence to the guidelines should be accompanied by significant reduction in patients' symptoms, reduced morbidity and mortality, fewer emergency and hospital admissions, fewer adverse side-effects from medications, better quality of life for patients and reduced costs.

RECOMMENDATIONS

Recommendations are included in each section of the report. In summary, after a diagnosis of asthma is made based on clinical evaluation, including demonstration of variable airflow obstruction, and contributing factors are identified, a treatment plan is established to obtain and maintain optimal asthma control. The main components of treatment are patient education, environmental control, pharmacotherapy tailored to the individual and regular follow-up.

VALIDATION

The recommendations were distributed to the members of the Canadian Thoracic Society Asthma and Standards Committees, as well as members of the board of the Canadian Thoracic Society. In addition, collaborating groups representing the Canadian Association of Emergency Physicians, the Canadian College of Family Physicians, the Canadian Paediatric Society and the Canadian Society of Allergy and Immunology were asked to validate the recommendations. The recommendations were discussed at regional meetings throughout Canada. They were also compared with the recommendations of other similar groups in other countries. DISSEMINATION AND IMPLEMENTATION: An implementation committee has established a strategy for disseminating these guidelines to physicians, other health professionals and patients and for developing tools and means that will help integrate the recommendations into current asthma care. The plan is outlined in this report.

Glutathione S-transferase P1 (GSTP1) polymorphism in patients with chronic obstructive pulmonary disease

BACKGROUND

Enzymes that contribute to the local detoxification in alveoli and bronchioles have an important role in the defence mechanism against tobacco smoke. It has been suggested that genetic susceptibility to smoking injury may confer a risk for the development of chronic obstructive pulmonary disease (COPD). The polymorphisms in glutathione S-transferase P1 (GSTP1), a xenobiotic metabolising enzyme, were investigated in patients with COPD.

METHODS

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were performed to genotype GSTP1 polymorphisms in exon 5 (Ile105Val) and exon 6 (Ala114Val). Blood samples were taken from 53 patients with COPD and 50 control subjects at the Tokyo University Hospital, the Juntendo University Hospital, and the Tokyo Kenbikyoin Clinic for use in the study.

RESULTS

The proportion of GSTP1/Ile105 homozygotes was significantly higher in the patients with COPD than in the control subjects (79% vs 52%). The odds ratio for GSTP1/Ile105 homozygotes versus all other genotypes was 3.5 (95% CI 2.7 to 4.6) for COPD. Polymorphism at residue 114 of GSTP1 was not found in either group.

CONCLUSIONS

Genetic polymorphism of exon 5 of GSTP1 may be associated with COPD because the GSTP1/Ile105 genotype is predominantly found in COPD. It is suggested that the GSTP1/Ile105 genotype may be less protective against xenobiotics in tobacco smoke.

Chronic bronchitis in Icelandic males: prevalence, sleep disturbances and quality of life

OBJECTIVE

To study the prevalence of chronic bronchitis in Iceland and some aspects of quality of life among those suffering from chronic bronchitis.

DESIGN

Postal questionnaires. SETTING, SUBJECTS: All Icelandic males born in the years 1913 and 1943 who were alive on 1 November 1993. Altogether 1175 (69.7%) responded.

MAIN OUTCOME MEASURES

Physical symptoms of chronic bronchitis, stress symptoms, symptoms of dyspnea and sleep disturbances.

RESULTS

7.1% of those 50 years old and 16.7% of those 80 years old and a history of daily sputum expectoration for at least 3 months during the preceding 2 years. These individuals with chronic bronchitis had a higher prevalence of other respiratory symptoms than did the others, such as "wheezing or whistling" (59.6% vs. 7.2%), and "awakened by breathlessness" (35.2% vs. 6.0%). Complaints of dyspnea were more common among those with symptoms of chronic bronchitis, e.g. "dyspnea when walking" (19.4% vs. 1.4%) and "stops walking because of dyspnea" (22% vs. 1.6%). They also complained more often of insomnia and daytime sleepiness and found themselves more stressed than those without chronic bronchitis. These symptoms were all more common among the 80-year-old men.

CONCLUSION

Our study indicates that chronic bronchitis is a frequent illness among Icelandic males. Men with chronic bronchitis often have decreased quality of life, difficulties in moving and frequently sleep complaints.

Imaging the 'dirty lung'--has high resolution computed tomography cleared the smoke?

The histopathological abnormalities that characterize cigarette smokers' lung damage have been widely studied, but these microscopic changes do not fully explain the radiographic features that have been loosely termed the 'dirty lung'. High resolution computed tomography is not only more sensitive for the detection of early emphysema, it has also provided the imaging correlates of subtle parenchymal changes of smokers, for example, respiratory bronchiolitis - interstitial lung disease. Nevertheless, some aspects of the radiographic 'dirty lung' remain enigmatic.