Incidence of chronic obstructive pulmonary disease in a cohort of young adults according to the presence of chronic cough and phlegm

Effective-Component Compatibility of Bufei Yishen Formula (ECC-BYF) III Inhibits Mucus Hypersecretion by BEAS-2B Cells via miR-146a-5p-Mediated Regulation of the EGFR/MEK/ERK Pathway

Purpose

To explore the role of the miR-146a-5p-mediated regulation of the EGFR/MEK/ERK pathway in the effect of effective-component compatibility of Bufei Yishen Formula III (ECC-BYF III) on ameliorating mucus hypersecretion by bronchial epithelial cells (BEAS-2B cells).

Methods

BEAS-2B cells exposed to cigarette smoke extract (CSE) were used to establish a mucus hypersecretion model of BEAS-2B cells. The optimal intervention concentration of ECC-BYF III was screened by CCK-8, qRT-PCR and ELISA, the effects of ECC-BYF III on MUC5AC, MUC5B, IL-4, IL-8, TNF-α, IL-1α, miR-146a-5p and EGFR/MEK/ERK pathway expression were assessed. Furthermore, dual luciferase reporter gene was used to verify the relationship between miR-146a-5p and EGFR/MEK/ERK, and to observe the effect of down-regulating miR-146a-5p on ECC-BYF III ameliorating mucus hypersecretion and EGFR/MEK/ERK pathway.

Results

ECC-BYF III reduced the expression of MUC5AC and MUC5B, decreased the mRNA expression of IL-1α, IL-8 and TNF-α, increased the mRNA expression of IL-4, and decreased the protein expression of TNF-α. Moreover, ECC-BYF III ameliorated CSE induced mucus hypersecretion in BEAS-2B cells through EGFR/MEK/ERK pathway. Finally, our results indicated that ECC-BYF III ameliorated the model by targeting miR-146a-5p and downregulating the EGFR/MEK/ERK pathway.

Conclusion

ECC-BYF III can ameliorate CSE induced mucus hypersecretion by BEAS-2B cells and reduce the inflammatory response. The underlying mechanism may be related to the regulation of miR-146a-5p and the EGFR/MEK/ERK pathway. ECC-BYF III can inhibit activation of the EGFR/MEK/ERK pathway by upregulating the expression of miR-146a-5p, thereby ameliorating mucus hypersecretion by BEAS-2B cells.

Machine learning-assisted construction of COPD self-evaluation questionnaire (COPD-EQ): a national multicentre study in China

Background

Approximately 70% of chronic obstructive pulmonary disease (COPD) is underdiagnosed worldwide. We aimed to develop and validate a COPD self-evaluation questionnaire (COPD-EQ) that is better suited for COPD screening in China.

Methods

We developed a primary version of COPD-EQ based on the Delphi method. Then, we conducted a nationwide multicentre prospective to validate our novel COPD-EQ screening ability. To improve the screening ability of COPD-EQ, we used a series of machine learning (ML)-based methods, including logistic regression, XgBoost, LightGBM, and CatBoost. These models were developed and then evaluated on a random 3:1 train/test split.

Results

Through the Delphi approach, we developed the primary version of COPD-EQ with nine items. In the following prospective multicentre study, we recruited 1824 outpatients from 12 sites, of whom 404 (22.1%) were diagnosed with COPD. After the score assignment assisted by ML models and the Shapley Additive Explanation method, six of nine items were retained for a briefer version of COPD-EQ. The scoring-based method achieves an AUC score of 0.734 at a threshold of 4.0. Finally, a novel six-item COPD-EQ questionnaire was developed.

Conclusions

The COPD-EQ questionnaire was validated to be reliable and accurate in COPD screening for the Chinese population. The ML model can further improve the questionnaire's screening ability.

Guiding therapy by fractional exhaled nitric oxide & impulse oscillometry parameters in non-asthmatic individuals with chronic cough

Background & objectives Chronic airway inflammation and airway hyperresponsiveness are typical pathophysiological features of cough variant asthma. However, the characteristics of airway inflammation and airflow restriction in individuals with non-asthmatic chronic cough and their guiding value of clinical treatment remain to be determined. This study explored the characteristics and correlations between fractional exhaled nitric oxide (FeNO) and impulse oscillometry (IOS) in non-asthmatic individuals with chronic cough. It also investigated the possibility of chronic cough developing into asthma. Methods In total, 65 study participants with negative bronchial provocation test (BPT) were included in this retrospective study. Data were extracted from chronic cough patients' electronic medical records, including the demographics, FeNO, IOS and spirometric parameters before and after BPT. Study participants were divided into high-FeNO group (FeNO≥25 ppb) and low-FeNO group (FeNO< 25 ppb) based on FeNO levels. The correlation between the markers was investigated using the Spearman rank correlation test. Results We observed that individuals with non-asthmatic chronic cough exhibited significant increases in Z5, Fres, R5 and R5-R20 after BPT compared to before BPT. In addition, the IOS values of Z5, Fres, R5, and Rc were higher in the low-FeNO group than in the high-FeNO group, but a decrease in FEV1. Correlation analysis: IOS parameters showed a negative correlation with FeNO. However, there were positive correlations of FeNO with FEV1 and PEF. Interpretation & conclusions Our findings showed that individuals with non-asthmatic chronic cough may have varying levels of small airway resistance and inflammation severity. A combined use of FeNO and IOS measurements is conducive to the early clinical treatment of individuals with non-asthmatic chronic cough.

The relationship between respiratory symptoms and frailty: findings from observational and Mendelian randomization analyses

INTRODUCTION

As ageing accelerates, frailty increasingly impacts public health. Cough, sputum, wheezing and dyspnea are common respiratory symptoms, and the relationship to frailty is unclear. We aimed to analyze the relationship between respiratory symptoms and frailty.

METHODS

Cross-sectional and Mendelian randomization (MR) studies were used. Cross-sectional data involved 14,021 participants from the National Health and Nutrition Examination Survey (NHANES). Logistic and linear regression were used to analyze the relationship between respiratory symptoms (cough, sputum, wheezing, dyspnea) and frailty. We adjusted for multiple variables and used propensity score matching (PSM). Mediation analysis was used to explore the role of inflammatory markers and age in the relationship between the two. We analyzed the relationship using a two-sample MR approach with data from genome-wide association studies (GWAS) to enhance causal inference.

RESULTS

Observational studies have shown that cough (OR 1.74, 95 CI% 1.44, 2.09), sputum (OR 1.87, 95 CI% 1.57, 2.22), wheezing (OR 2.01, 95 CI% 1.68, 2.40), and dyspnea (OR 2.60, 95 CI% 2.28, 2.97) are associated with an elevated risk of frailty. The PSM results were stable. Mediation analyses indicated that elevated inflammatory markers and advancing age were mediators between respiratory symptoms and frailty. The results of the MR study showed that sputum and wheezing were associated with an elevated frailty index; and in the study of FI on respiratory symptoms, all respiratory symptoms were elevated with elevated FI.

CONCLUSIONS

Our study identified a potential association between frailty and respiratory symptoms. Inflammation and ageing may be essential factors mediating this association.

A Study on the Association between Cough Sensitivity and Acute Exacerbations in Patients with Chronic Obstructive Pulmonary Disease

OBJECTIVE

To investigate the relationship between cough sensitivity and acute exacerbation in stable chronic obstructive pulmonary disease (COPD) patients.

METHODS

Stable COPD patients who visited our department from July 2022 to June 2023 were included. They were subjected to cough sensitivity test, spirometry, induced sputum cytology examination, questionnaire assessment such as cough symptom score, etc. They were followed up for 12 months, and were divided into the acute exacerbation (AE) group and the stable group according to whether acute exacerbation occurred during the follow-up period. We compared the differences in cough sensitivity, pulmonary function, and questionnaires between the two groups, analyzed the relationship between cough sensitivity and acute exacerbation, and screened the risk factors for AECOPD.

RESULTS

A total of 145 patients with stable COPD were included. AE group (n = 94) had lower FEV1/FVC (50.08 ± 11.11 versus 54.28 ± 11.58, p = 0.03) and cough sensitivity lgC5 [-0.01(0.90) versus 0.59(0.90), p < 0.01] than those in the stable group (n = 51) patients, the daytime cough symptom score [2(2) versus 1(2), p = 0.02] and VAS score [50(40) versus 30(50), p < 0.01] were higher than stable group. Multivariate logistic regression analysis showed lgC5 (OR = 0.34, 95% CI = 0.16-0.71, p < 0.01) was an independent risk factor for AECOPD. When lgC5 was used to predict acute exacerbation in stable COPD patients, the AUC was 0.69, the sensitivity was 59.57%, and the specificity was 72.55%.

CONCLUSION

Although causality is not necessarily demonstrated, baseline cough sensitivity lgC5 in stable COPD patients is an independent risk factor for AECOPD, and it has some predictive value for future acute exacerbations.

Silent Airway Mucus Plugs in COPD and Clinical Implications

BACKGROUND

Airway mucus plugs are frequently identified on CT scans of patients with COPD with a smoking history without mucus-related symptoms (ie, cough, phlegm [silent mucus plugs]).

RESEARCH QUESTION

In patients with COPD, what are the risk and protective factors associated with silent airway mucus plugs? Are silent mucus plugs associated with functional, structural, and clinical measures of disease?

STUDY DESIGN AND METHODS

We identified mucus plugs on chest CT scans of participants with COPD from the COPDGene study. The mucus plug score was defined as the number of pulmonary segments with mucus plugs, ranging from 0 to 18, and categorized into three groups (0, 1-2, and ≥ 3). We determined risk and protective factors for silent mucus plugs and the associations of silent mucus plugs with measures of disease severity using multivariable linear and logistic regression models.

RESULTS

Of 4,363 participants with COPD, 1,739 had no cough or phlegm. Among the 1,739 participants, 627 (36%) had airway mucus plugs identified on CT scan. Risk factors of silent mucus plugs (compared with symptomatic mucus plugs) were older age (OR, 1.02), female sex (OR, 1.40), and Black race (OR, 1.93) (all P values < .01). Among those without cough or phlegm, silent mucus plugs (vs absence of mucus plugs) were associated with worse 6-min walk distance, worse resting arterial oxygen saturation, worse FEV1 % predicted, greater emphysema, thicker airway walls, and higher odds of severe exacerbation in the past year in adjusted models.

INTERPRETATION

Mucus plugs are common in patients with COPD without mucus-related symptoms. Silent mucus plugs are associated with worse functional, structural, and clinical measures of disease. CT scan-identified mucus plugs can complement the evaluation of patients with COPD.

Industry 4.0-Compliant Occupational Chronic Obstructive Pulmonary Disease Prevention: Literature Review and Future Directions

Chronic obstructive pulmonary disease (COPD) is among prevalent occupational diseases, causing early retirement and disabilities. This paper looks into occupational-related COPD prevention and intervention in the workplace for Industry 4.0-compliant occupation health and safety management. The economic burden and other severe problems caused by COPD are introduced. Subsequently, seminal research in relevant areas is reviewed. The prospects and challenges are introduced and discussed based on critical management approaches. An initial design of an Industry 4.0-compliant occupational COPD prevention system is presented at the end.

It is high time to discard a cut-off of 0.70 in the diagnosis of COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) has traditionally been diagnosed based on the criterion of an FEV1/FVC <0.70. However, this definition has limitations as it may only detect patients with later-stage disease, when pathologic changes have become irreversible. Consequently, it potentially omits individuals with early-stage disease, in whom the pathologic changes could be delayed or reversed.

AREAS COVERED

This narrative review summarizes recent evidence regarding early-stage COPD, which may not fulfill the spirometric criteria but nonetheless exhibits features of COPD or is at risk of future COPD progression.

EXPERT OPINION

A comprehensive approach, including symptoms assessment, various physiologic tests, and radiologic features, is required to diagnose COPD. This approach is necessary to identify currently underdiagnosed patients and to halt disease progression in at- risk patients.

Efficacy and safety of Cordyceps sinensis (Hirsutella sinensis, Cs-C-Q80) in chronic bronchitis

Background: Cordyceps sinensis is a traditional Chinese medicine that has shown promise for the management of chronic bronchitis (CB). We aim to assess the efficacy and safety of a preparation of C sinensis named Bailing capsule (Hirsutella sinensis, Cs-C-Q80) compared with a placebo in patients with CB. Methods: This randomized, double-blind, placebo-controlled, parallel-group clinical trial (Chinese Clinical Trial Registry; registration number: ChiCTR1900025707) recruited patients with CB from eight hospitals in China between May 2019 and December 2020. Patients were randomized 2:1 to receive Bailing capsule or a placebo orally for 48 weeks (2.0 g, three times a day). Results: Among 240 patients who were randomized, 238 (Bailing capsule: 159, placebo: 79) were included in the primary analysis. Bailing capsule significantly reduced the frequency of acute exacerbation of CB (AECB) compared with the placebo during treatment (0.43 ± 0.82 vs. 1.56 ± 1.34; P < 0.001) and follow-up (0.21 ± 0.64 vs. 0.45 ± 0.93; P = 0.026). Bailing capsule improved the severity of expectoration (P = 0.046) and wheezing (P = 0.010) in AECB during follow-up. The severity of CB after treatment was significantly improved in the Bailing capsule group compared with the placebo group (P = 0.035), particularly in terms of expectoration (P = 0.012) and wheezing (P = 0.003). The risk of adverse events, mainly including infectious and invasive diseases and gastrointestinal symptoms, did not significantly differ between the two groups (29.6% vs. 30.4%). Conclusion: In patients with CB, Bailing capsule significantly reduces the frequency of AECB and ameliorates the severity of AECB and CB symptoms. Clinical Trail Registration: https://www.chictr.org.cn, identifer ChiCTR1900025707.

Burden of headaches, eye irritation and respiratory symptoms among females stacking LPG with polluting cooking fuels: Modelling from peri-urban Cameroon, Ghana & Kenya

Introduction

Liquefied petroleum gas (LPG) is a clean cooking fuel that emits less household air pollution (HAP) than polluting cooking fuels (e.g. charcoal, wood). While switching from polluting fuels to LPG can reduce HAP and improve health, the impact of 'stacking' (concurrent use of polluting fuels and LPG) on adverse health symptoms (e.g. headaches, eye irritation, cough) among female cooks is uncertain.

Methods

Survey data from the CLEAN-Air(Africa) study was collected on cooking patterns and health symptoms over the last 12 months (cough, wheezing, chest tightness, shortness of breath, eye irritation, headaches) from approximately 400 female primary cooks in each of three peri‑urban communities in sub-Saharan Africa: Mbalmayo, Cameroon; Obuasi, Ghana; and Eldoret, Kenya. Random effects Poisson regression, adjusted for socioeconomic and health-related covariates, assessed the relationship between primary and secondary cooking fuel type and self-reported health symptoms.

Results

Among 1,147 participants, 10 % (n = 118) exclusively cooked with LPG, 45 % (n = 509) stacked LPG and polluting fuels and 45 % (n = 520) exclusively cooked with polluting fuels. Female cooks stacking LPG and polluting fuels had significantly higher odds of shortness of breath (OR 2.16, 95 %CI:1.04-4.48) compared with those exclusively using LPG. In two communities, headache prevalence was 30 % higher among women stacking LPG with polluting fuels (Mbalmayo:82 %; Eldoret:65 %) compared with those exclusively using LPG (Mbalmayo:53 %; Eldoret:33 %). Women stacking LPG and polluting fuels (OR 2.45, 95 %CI:1.29-4.67) had significantly higher odds of eye irritation than women cooking exclusively with LPG. Second-hand smoke exposure was significantly associated with higher odds of chest tightness (OR 1.92, 95 % CI:1.19-3.11), wheezing (OR 1.76, 95 % CI:1.06-2.91) and cough (OR 1.78, 95 %CI:1.13-2.80).

Conclusions

In peri‑urban sub-Saharan Africa, women exclusively cooking with LPG had lower odds of several health symptoms than those stacking LPG and polluting fuels. Promoting a complete transition to LPG in these communities may likely generate short-term health benefits for primary cooks.

Potential pre-COPD indicators in association with COPD development and COPD prediction models in Chinese: a prospective cohort study

Background

Lung injury might take place before chronic obstructive pulmonary disease (COPD) occurs. A clearer definition of "pre-COPD" based on the effects of potential indicators on increasing risk of COPD development and a prediction model involving them are lacking.

Methods

A total of 3526 Chinese residents without COPD aged 40 years or older derived from the national cross-sectional survey of COPD surveillance in 2014-2015 were followed up for a mean of 3.59 years. We examined the associations of chronic bronchitis, preserved ratio impaired spirometry (PRISm), low peak expiratory flow (PEF), spirometric small airway dysfunction (sSAD), low maximal mid-expiratory flow (MMEF), low forced expiratory flow 50% of pulmonary volume (FEF50), and low FEF75 with subsequent COPD and constructed a prediction model with LASSO-Cox regression.

Findings

235 subjects in the cohort developed COPD during the follow-up. Subjects with PRISm, low PEF, sSAD, low MMEF, low FEF50, and low FEF75 had an increased risk of developing COPD (adjusted hazard ratio [HR] ranging from 1.57 to 3.01). Only chronic bronchitis (HR 2.84 [95% CI 1.38-5.84] and 2.94 [1.43-6.04]) and sSAD/low MMEF (HR 2.74 [2.07-3.61] and 2.38 [1.65-3.43]) showed effects independent of the other indicators and their concurrence had the strongest effect (HR 5.89 and 4.80). The prediction model including age, sex, low MMEF, low FEF50, and indoor exposure to biomass had good performance both internally and temporally. The corrected C-index was 0.77 (0.72-0.81) for discrimination in internal validation. For temporal validation, the area under the receiver operating characteristic curve was 0.73 (0.63-0.83). Good calibration was indicated in plot for internal validation and by Hosmer-Lemeshow test for temporal validation.

Interpretation

Individuals with concurrent chronic bronchitis and sSAD/low MMEF indicating pre-COPD optimally require more high attention from physicians. Our prediction model could serve as a multi-dimension tool to predict COPD comprehensively.

Funding

The Ministry of Finance and the Ministry of Science and Technology of the People's Republic of China and the National Natural Science Foundation of China.

Association of non-obstructive dyspnoea with all-cause mortality and incident chronic obstructive pulmonary disease: a systematic literature review and meta-analysis

BACKGROUND

Controversy exists regarding the association between non-obstructive dyspnoea and the future development of chronic obstructive pulmonary disease (COPD) and mortality. Therefore, we aimed to evaluate the association of non-obstructive dyspnoea with mortality and incident COPD in adults.

METHODS

We searched PubMed, Embase, and Web of Science to identify studies published from inception to 13 May 2023. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. Studies were included if they were original articles comparing incident COPD and all-cause mortality between individuals with normal lung function with and without dyspnoea. The primary outcomes were incident COPD and all-cause mortality. The secondary outcome was respiratory disease-related mortality. We used the random-effects model to calculate pooled estimates and corresponding 95% confidence interval (CI). Heterogeneity was determined using the I² statistic.

RESULTS

Of 6486 studies, 8 studies involving 100 758 individuals fulfilled the inclusion and exclusion criteria and were included in the study. Compared with individuals without non-obstructive dyspnoea, individuals with non-obstructive dyspnoea had an increased risk of incident COPD (relative risk: 1.41, 95% CI: 1.08 to 1.83), and moderate heterogeneity was found (p=0.079, I2=52.2%). Individuals with non-obstructive dyspnoea had a higher risk of all-cause mortality (hazard ratio: 1.21, 95% CI: 1.14 to 1.28, I2=0.0%) and respiratory disease-related mortality (hazard ratio: 1.52, 95% CI: 1.14 to 2.02, I2=0.0%) than those without.

CONCLUSIONS

Individuals with non-obstructive dyspnoea are at a higher risk of incident COPD and all-cause mortality than individuals without dyspnoea. Further research should investigate whether these high-risk adults may benefit from risk management and early therapeutic intervention.

PROSPERO REGISTRATION NUMBER

CRD42023395192.

From treatable traits to GETomics in airway disease: moving towards clinical practice

The treatable traits approach represents a strategy for patient management. It is based on the identification of characteristics susceptible to treatments or predictive of treatment response in each individual patient. With the objective of accelerating progress in research and clinical practice relating to such a treatable traits approach, the Portraits event was convened in Barcelona, Spain, in November 2022. Here, while reporting the key concepts that emerged from the discussions during the meeting, we review the current state of the art related to treatable traits and chronic respiratory diseases management, and we describe the possible actions that clinicians can take in clinical practice to implement the treatable traits framework. Furthermore, we explore the new concept of GETomics and the new models of research in the field of COPD.

Longitudinal Follow-Up of Participants With Tobacco Exposure and Preserved Spirometry

Importance

People who smoked cigarettes may experience respiratory symptoms without spirometric airflow obstruction. These individuals are typically excluded from chronic obstructive pulmonary disease (COPD) trials and lack evidence-based therapies.

Objective

To define the natural history of persons with tobacco exposure and preserved spirometry (TEPS) and symptoms (symptomatic TEPS).

Design, Setting, and Participants

SPIROMICS II was an extension of SPIROMICS I, a multicenter study of persons aged 40 to 80 years who smoked cigarettes (>20 pack-years) with or without COPD and controls without tobacco exposure or airflow obstruction. Participants were enrolled in SPIROMICS I and II from November 10, 2010, through July 31, 2015, and followed up through July 31, 2021.

Exposures

Participants in SPIROMICS I underwent spirometry, 6-minute walk distance testing, assessment of respiratory symptoms, and computed tomography of the chest at yearly visits for 3 to 4 years. Participants in SPIROMICS II had 1 additional in-person visit 5 to 7 years after enrollment in SPIROMICS I. Respiratory symptoms were assessed with the COPD Assessment Test (range, 0 to 40; higher scores indicate more severe symptoms). Participants with symptomatic TEPS had normal spirometry (postbronchodilator ratio of forced expiratory volume in the first second [FEV1] to forced vital capacity >0.70) and COPD Assessment Test scores of 10 or greater. Participants with asymptomatic TEPS had normal spirometry and COPD Assessment Test scores of less than 10. Patient-reported respiratory symptoms and exacerbations were assessed every 4 months via phone calls.

Main Outcomes and Measures

The primary outcome was assessment for accelerated decline in lung function (FEV1) in participants with symptomatic TEPS vs asymptomatic TEPS. Secondary outcomes included development of COPD defined by spirometry, respiratory symptoms, rates of respiratory exacerbations, and progression of computed tomographic-defined airway wall thickening or emphysema.

Results

Of 1397 study participants, 226 had symptomatic TEPS (mean age, 60.1 [SD, 9.8] years; 134 were women [59%]) and 269 had asymptomatic TEPS (mean age, 63.1 [SD, 9.1] years; 134 were women [50%]). At a median follow-up of 5.76 years, the decline in FEV1 was -31.3 mL/y for participants with symptomatic TEPS vs -38.8 mL/y for those with asymptomatic TEPS (between-group difference, -7.5 mL/y [95% CI, -16.6 to 1.6 mL/y]). The cumulative incidence of COPD was 33.0% among participants with symptomatic TEPS vs 31.6% among those with asymptomatic TEPS (hazard ratio, 1.05 [95% CI, 0.76 to 1.46]). Participants with symptomatic TEPS had significantly more respiratory exacerbations than those with asymptomatic TEPS (0.23 vs 0.08 exacerbations per person-year, respectively; rate ratio, 2.38 [95% CI, 1.71 to 3.31], P < .001).

Conclusions and Relevance

Participants with symptomatic TEPS did not have accelerated rates of decline in FEV1 or increased incidence of COPD vs those with asymptomatic TEPS, but participants with symptomatic TEPS did experience significantly more respiratory exacerbations over a median follow-up of 5.8 years.

Twenty years of changes in the definition of early chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease that affects the quality of life of nearly one-tenth of the global population. Due to irreversible airflow obstruction and progressive lung function decline, COPD is characterized by high mortality and disability rates, which imposes a huge economic burden on society. In recent years, the importance of intervention in the early stage of COPD has been recognized and the concept of early COPD has been proposed. Identifying and intervening in individuals with early COPD, some of whom have few or no symptoms, might halt or reverse the progressive decline in lung function, improve the quality of life, and better their prognosis. However, understanding of early COPD is not yet well established, and there are no unified and feasible diagnostic criteria, which complicates clinical research. In this article, we review evolution of the definition of early COPD over the past 20 years, describe the changes in awareness of this concept, and propose future research directions.

Incidence of interstitial lung abnormalities: the MESA Lung Study

BACKGROUND

The incidence of newly developed interstitial lung abnormalities (ILA) and fibrotic ILA has not been previously reported.

METHODS

Trained thoracic radiologists evaluated 13 944 cardiac computed tomography scans for the presence of ILA in 6197 Multi-Ethnic Study of Atherosclerosis (MESA) longitudinal cohort study participants >45 years of age from 2000 to 2012. Five percent of the scans were re-read by the same or a different observer in a blinded fashion. After exclusion of participants with ILA at baseline, incidence rates and incidence rate ratios for ILA and fibrotic ILA were calculated.

RESULTS

The intra-reader agreement of ILA was 92.0% (Gwet's AC1 0.912, intraclass correlation coefficient (ICC) 0.982) and the inter-reader agreement of ILA was 83.5% (Gwet's AC1 0.814, ICC 0.969). Incidence of ILA and fibrotic ILA was estimated to be 13.1 and 3.5 cases per 1000 person-years, respectively. In multivariable analyses, age (hazard ratio (HR) 1.06 (95% CI 1.05-1.08); p<0.001 and HR 1.08 (95% CI 1.06-1.11); p<0.001), high attenuation area at baseline (HR 1.05 (95% CI 1.03-1.07); p<0.001 and HR 1.06 (95% CI 1.02-1.10); p=0.002) and the MUC5B promoter single nucleotide polymorphism (HR 1.73 (95% CI 1.17-2.56); p=0.01 and HR 4.96 (95% CI 2.68-9.15); p<0.001) were associated with incident ILA and fibrotic ILA, respectively. Ever-smoking (HR 2.31 (95% CI 1.34-3.96); p=0.002) and an idiopathic pulmonary fibrosis polygenic risk score (HR 2.09 (95% CI 1.61-2.71); p<0.001) were associated only with incident fibrotic ILA.

CONCLUSIONS

Incident ILA and fibrotic ILA were estimated by review of cardiac imaging studies. These findings may lead to wider application of a screening tool for atherosclerosis to identify pre-clinical lung disease.

CT airway remodelling and chronic cough

RATIONALE

Structural airway changes related to chronic cough (CC) are described in the literature, but so far reported data are rare and non-conclusive. Furthermore, they derive mainly from cohorts with small sample sizes. Advanced CT imaging not only allows airway abnormalities to be quantified, but also to count the number of visible airways. The current study evaluates these airway abnormalities in CC and assesses the contribution of CC in addition to CT findings on the progression of airflow limitation, defined as a decline in forced expiratory volume in 1 s (FEV1) over time.

METHODS

A total of 1183 males and females aged ≥40 years with thoracic CT scans and valid spirometry from Canadian Obstructive Lung Disease, a Canadian multicentre, population-based study has been included in this analysis. Participants were stratified into 286 never-smokers, 297 ever-smokers with normal lung function and 600 with chronic obstructive pulmonary disease (COPD) of different severity grades. Imaging parameters analyses included total airway count (TAC), airway wall thickness, emphysema as well as parameters for functional small airway disease quantification.

RESULTS

Irrespective of COPD presence, CC was not related to specific airway and lung structure features. Independent of TAC and emphysema score, CC was highly associated with FEV1 decline over time in the entire study population, particularly in ever-smokers (p<0.0001).

CONCLUSION

The absence of specific structural CT features independently from COPD presence indicate that other underlying mechanisms are contributing to the symptomatology of CC. On top of derived CT parameters, CC seems to be independently associated with FEV1 decline.

TRIAL REGISTRATION NUMBER

NCT00920348.

Is telerehabilitation an effective maintenance strategy for patients with chronic obstructive pulmonary diseases: a systematic review

BACKGROUND

Pulmonary rehabilitation (PR) has proven to improve the physical and psychosocial function in patients with chronic obstructive pulmonary disease (COPD). However, the gains achieved during pulmonary rehabilitation diminish over time without an effective maintenance strategy. With several factors affecting access to pulmonary rehabilitation, calls for innovative models were made, which saw the emergence of studies exploring telerehabilitation (TR) as an alternative to traditional pulmonary rehabilitation models. Although there are current reviews exploring the effectiveness of telerehabilitation as an alternative for conventional PR, no review has considered telerehabilitation effectiveness in the long term. Hence, this review aims at examining the effectiveness of telerehabilitation following to pulmonary rehabilitation in patients with chronic obstructive pulmonary disease.

MAIN BODY

A systematic review of the literature using CINAHL, MEDLINE, SCOPUS, Web of science PEDRO, AMED and EMBASE databases was conducted to assess the effectiveness of telerehabilitation following PR in patients with COPD. Health-related quality of life (HRQoL) and exercise capacity was maintained within 6-12 months of a TR maintenance programme. However, there was no significant increase in HRQoL and exercise capacity between the intervention and control groups in 6-12 months.

CONCLUSIONS

This review suggests that a TR maintenance strategy effectively maintains benefits gained and may improve HRQoL and exercise capacity within 6-12 months for patients with COPD. Nonetheless, it is impossible to extrapolate the findings to the general population due to the paucity of included studies. Further high quality randomised controlled trials examining TR in the long-term is required in the future.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s42269-023-00980-8.

The association between sleep duration, respiratory symptoms, asthma, and COPD in adults

Introduction

The association between sleep duration and cough, wheezing, and dyspnea was unclear. This research aimed to test this relationship.

Methods

Research data were obtained from people who participated in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2012. We used weighted logistic regression analysis and fitted curves to explore the association between sleep and respiratory symptoms. In addition, we investigated the association between sleep duration, chronic obstructive pulmonary disease (COPD), and asthma. The stratified analysis is used to analyze inflection points and specific populations.

Results

The 14,742 subjects are weighted to reflect the 45,678,491 population across the United States. Weighted logistic regression and fitted curves show a U-shaped relationship between sleep duration and cough and dyspnea. This U-shaped relationship remained in people without COPD and asthma. The stratified analysis confirmed that sleep duration before 7.5 h was negatively associated with cough (HR 0.80, 95% CI 0.73-0.87) and dyspnea (HR 0.82, 95% CI 0.77-0.88). In contrast, it was positively associated with cough and (HR 1.30, 95% CI 1.14-1.48) dyspnea (HR 1.12, 95% CI 1.00-1.26) when sleep duration was >7.5 h. In addition, short sleep duration is associated with wheezing, asthma, and COPD.

Conclusion

Both long and short sleep duration are associated with cough and dyspnea. And short sleep duration is also an independent risk factor for wheezing, asthma, and COPD. This finding provides new insights into the management of respiratory symptoms and diseases.

AA, Kudriaeva AA, Bugrimov DY, Krasnorutskaya ON, Murashev AN. Derinat® has an immunomodulatory and anti-inflammatory effect on the model of acute lung injury in male SD rats

To simulate acute lung injury (ALI) in SD male rats they we administered intratracheally with lipopolysaccharide (LPS) followed by hyperventilation of the lungs (HVL), which lead to functional changes in the respiratory system and an increase in the blood serum concentration of inflammatory cytokines. LPS + HVL after 4 h lead to pronounced histological signs of lung damage. We have studied the effectiveness of Derinat^® when administered intramuscularly at dose of 7.5 mg/kg for 8 days in the ALI model. Derinat^® administration lead to an increase in the concentration of most of the studied cytokines in a day. In the ALI model the administration of Derinat^® returned the concentration of cytokines to its original values already 48 h after LPS + HVL, and also normalized the parameters of pulmonary respiration in comparison with animals without treatment. By the eighth day after LPS + HVL, respiratory parameters and cytokine levels, as well as biochemical and hematological parameters did not differ between groups, while histological signs of residual effects of lung damage were found in all animals, and were more pronounced in Derinat^® group, which may indicate stimulation of the local immune response. Thus, the administration of Derinat^® stimulates the immune response, has a pronounced protective effect against cytokinemia and respiratory failure caused by ALI, has immunomodulatory effect, and also stimulates a local immune response in lung tissues. Thus, Derinat^® is a promising treatment for ALI.

Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations: strengths and concerns for future needs

Chronic Obstructive Pulmonary Disease (COPD) is already the third leading cause of death worldwide and simultaneously a major cause of morbidity and mortality. Global initiative for Chronic Obstructive Lung Disease (also known as GOLD) committee, has been created in 1997 to increase the awareness regarding the burden of COPD. GOLD recommendations have been contributing to diagnosis, management and therapy of COPD since 2001. Through these years, by reviewing published articles, GOLD aimed to provide state-of-the-art information not only for pulmonologists, but also for non-respiratory physicians, and to encourage research on COPD. From 2011, GOLD annual reports have changed the way of COPD evaluation from based entirely on spirometric parameters to more clinical indices, such as the assessment of symptoms and dyspnea alongside with exacerbations. Moreover, according to recent developments in pathophysiology of COPD, there is a trend in identifying new pre-clinical stages, contributing to prevention and early COPD treatment. In the field of therapeutic algorithms, changes turn to a more personalized approach. However, it is not clear in what extent this personalized disease management would be feasible and the real challenge for current recommendations is to include more patient characteristics such as co-morbidities and multidimensional scores in disease evaluation.

Small Airway Dysfunction in Chronic Bronchitis with Preserved Pulmonary Function

Impairment of pulmonary function was evaluated in chronic bronchitis patients with preserved ratio impaired spirometry (PRISm). We retrospectively collected clinical data from 157 chronic bronchitis (CB) and 186 chronic obstructive pulmonary disease (COPD) patients between October 2014 and September 2017. These patients were assigned to three groups: control (normal pulmonary function), PRISm (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ≥ 0.7, FEV1 < 80% of predicted value), and COPD (FEV1/FVC <0.7) groups. Because small airway function was the main focus, in the COPD group, only patients in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1 and 2 were included. Evaluation of pulmonary function (including impulse oscillometry) was performed and compared among these groups. Compared with the control group, the PRISm and COPD groups showed statistically significant differences in the predicted FEV1% $\left(p<0.001\right)$ , maximal expiratory flow (MEF) 25% $\left(p<0.001\right)$ , MEF50% $\left(p<0.001\right)$ , maximal midexpiratory flow (MMEF) 25–75% $\left(p<0.001\right)$ , residual volume (RV)/total lung capacity (TLC; $p<0.001$ ), FVC% $\left(p<0.001\right)$ , total respiratory resistance and proximal respiratory resistance (R5-R20; $p<0.001$ ), respiratory system reactance at 5 Hz (X5; $p<0.001$ ), resonant frequency (Fres; $p<0.001$ ), and area of reactance (Ax; $p<0.001$ ). However, the predicted FEV1% and RV/TLC were similar between the PRISm and COPD groups ( $p=0.992$ and 0.122, respectively). PRISm is a nonspecific pattern of pulmonary function that indicates small airway dysfunction and may increase the risk of transformation to obstructive ventilation dysfunction. This trial is registered with ChiCTR-OCH-14004904.

Chronic Bronchitis Affects Outcomes in Smokers without Chronic Obstructive Pulmonary Disease (COPD)

Background. Chronic bronchitis (CB) importantly affects outcomes in smokers with COPD, but the effects on smokers without COPD are less well known and less emphasized. The aim of our study was to investigate the possible effects of CB on clinical outcomes in smokers without COPD (noCOPD) and compare them with the effects in smokers with COPD (COPD). Methods. For that purpose, we studied 511 smokers, 302 with and 209 without COPD, followed for 10 years in an academic COPD ambulatory setting. Chronic bronchitis was defined as the presence of cough and sputum production for at least 3 months in each of two consecutive years. All subjects underwent clinical and functional examination with spirometry, diffusion capacity (DLco), 6-min walking test (6MWT), mMRC Dyspnoea Scale, COPD Assessment Test (CAT), and recording of annual frequency of exacerbations. All-cause mortality during follow-up was recorded. Results. 27% of noCOPD and 45% of COPD had CB. noCOPD with CB had lower FEV₁ and DLco, worse 6MWT, more dyspnoea, a higher number of exacerbations and lower survival than noCOPD without CB. CB did not affect FEV₁ decline in noCOPD but it significantly did in COPD. Conclusions. The presence of chronic bronchitis in smokers without COPD will significantly affect symptoms, quality of life, and survival, underlining the importance of recognizing the condition and managing it accordingly.

Respiratory Symptoms among US Adults: a Cross-Sectional Health Survey Study

INTRODUCTION

Data collected through ongoing, state-based, cross-sectional health surveys could be used to better understand the contribution of respiratory symptoms to impaired health among the US adult population.

METHODS

We used the 2015 Behavioral Risk Factor Surveillance System telephone health survey in four states (Kentucky, Florida, South Carolina, Texas) to describe the relationship between symptoms, associated factors such as tobacco smoking, and health impairments. Self-reported productive cough, shortness of breath (SOB), and dyspnea on exertion (DOE) were categorized as minimal, moderate, or severe. Data were analyzed using multiple logistic regression models with age as a covariate to assess relationships of symptoms with other factors.

RESULTS

Among adults ≥ 18 years, respiratory impairment [current asthma, chronic obstructive pulmonary disease (COPD), or a current moderate or severe symptom] occurred in 39.1% of the population. More than half of adults reporting moderate or severe symptoms had not been diagnosed with asthma or COPD, particularly with DOE and productive cough. Subjects were at greater risk of moderate and severe SOB or productive cough with increasing age, prolonged smoking duration (≥ 20 years), being an ever-smoker, or if reporting COPD, current asthma, or any other comorbidity except cancer. Morbid obesity [body mass index (BMI) > 35 kg/m²] was associated with severe DOE at a rate similar to current asthma or COPD (25.6%, 95% CI 20.9-30.3%; 20.8%, 95% CI 16.4-25.1%; 21.3%, 95% CI 17.5-25.1%, respectively); it was the most common cause of DOE. SOB was associated with worse general health impairment and limited ambulation compared with other symptoms. Tobacco smoking prevalence and race varied among states, affecting symptom prevalence.

CONCLUSION

In the largest US survey in decades, we provide a current perspective of respiratory symptoms among adults of all ages. While known risk factors were apparent, low-risk persons also frequently reported symptoms and impairments.

Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity, mortality, and health-care use worldwide. COPD is caused by exposure to inhaled noxious particles, notably tobacco smoke and pollutants. However, the broad range of factors that increase the risk of development and progression of COPD throughout the life course are increasingly being recognised. Innovations in omics and imaging techniques have provided greater insight into disease pathobiology, which might result in advances in COPD prevention, diagnosis, and treatment. Although few novel treatments have been approved for COPD in the past 5 years, advances have been made in targeting existing therapies to specific subpopulations using new biomarker-based strategies. Additionally, COVID-19 has undeniably affected individuals with COPD, who are not only at higher risk for severe disease manifestations than healthy individuals but also negatively affected by interruptions in health-care delivery and social isolation. This Seminar reviews COPD with an emphasis on recent advances in epidemiology, pathophysiology, imaging, diagnosis, and treatment.

Association Between Non-obstructive Chronic Bronchitis and Incident Chronic Obstructive Pulmonary Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis

Background

Chronic bronchitis in patients with chronic obstructive pulmonary disease (COPD) is associated with poor respiratory health outcomes. However, controversy exists around whether non-obstructive chronic bronchitis (NOCB) is associated with airflow obstruction, lung function decline, and all-cause mortality in ever smoker or never smoker.

Research Question

This systematic review and meta-analysis aimed to clarify the relationship between NOCB and incident COPD, lung function decline, and all-cause mortality, and to quantify the magnitude of these associations.

Study Design and Methods

We searched PubMed, Embase, and Web of Science for studies published up to October 1, 2021. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. Studies were included if they were original articles comparing incident COPD, lung function decline, and all-cause mortality in normal spirometry with and without chronic bronchitis. The primary outcomes were incident COPD and all-cause mortality. The secondary outcomes were respiratory disease-related mortality and lung function decline. Pooled effect sizes and 95% confidence intervals (CIs) were calculated using the random-effects model.

Results

We identified 17,323 related references and included 14 articles. Compared with individuals without NOCB, individuals with NOCB had an increased risk of incident COPD (odds ratio: 1.98, 95% CI: 1.21–3.22, I² = 76.3% and relative risk: 1.44, 95%CI: 1.13–1.85, I² = 56.1%), all-cause mortality (hazard ratio [HR]: 1.38, 95%CI: 1.26–1.51, I² = 29.4%), and respiratory disease-related mortality (HR: 1.88, 95%CI: 1.37–2.59, I² = 0.0%). Data on the decline in lung function could not be quantitatively synthesized, but the five articles that assessed the rate of decline in lung function showed that lung function declines faster in individuals with NOCB. The mean difference in the additional decline in forced expiratory volume in 1 s ranged from 3.6 to 23.2 mL/year.

Interpretation

Individuals with NOCB are at a higher risk of incident COPD and all-cause mortality than individuals without NOCB, highlighting the crucial need for strategies to screen for and reduce NOCB risk.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/ PROSPERO, identifier CRD42020202837

Clinical Impact of the Bronchiectasis with Chronic Bronchitis Symptoms in COPD: Analysis of a Longitudinal Cohort

Purpose

Bronchiectasis (BE) is a poor prognostic factor in COPD. However, it is not clear whether the poor prognosis is a result of BE alone or accompanying chronic bronchitis symptoms. Therefore, we investigated the effect of chronic bronchitis symptoms on clinical outcomes in COPD patients with BE.

Patients and Methods

We analyzed data of COPD patients from the Korean Obstructive Lung Disease (KOLD) cohort. The presence of BE was verified by chest computed tomography. Chronic bronchitis symptoms were determined using items in the symptomatic domain of the SGRQ, which is also used as an alternative definition of chronic bronchitis (CB). Patients were divided into four groups according to the presence of BE and CB symptoms: BE/CB, BE-only, CB-only, and no BE/CB. Demographic features and clinical outcomes were compared among these groups.

Results

In total, 389 COPD patients were included in the analysis. BE was present in 148 (38%) patients and CB symptoms were found in 123 patients (33.2%). The patients were divided according to BE and CB symptoms, and the numbers and percentages of each group were as follows: BE/CB, 52 (13.4%); BE-only, 96 (24.7%); CB-only, 77 (19.8%); no BE/CB, 164 (42.2%). No significant differences were observed in baseline characteristics of lung function, radiological findings, and inflammatory markers among the four groups. The proportion of annual exacerbators was higher in the BE/CB and CB-only groups than the other two groups. After adjusting other parameters, the BE/CB group was significantly associated with acute exacerbation of COPD (AE-COPD) (OR = 2.110, p = 0.045).

Conclusion

BE accompanying CB symptoms is associated with AE-COPD, while BE alone was not significantly associated. This finding suggests that it is more important to examine chronic bronchitis symptoms of BE to predict acute exacerbation than simply to identify BE in COPD patients.

Case-finding and improving patient outcomes for chronic obstructive pulmonary disease in primary care: the BLISS research programme including cluster RCT

Background

Chronic obstructive pulmonary disease is a major contributor to morbidity, mortality and health service costs but is vastly underdiagnosed. Evidence on screening and how best to approach this is not clear. There are also uncertainties around the natural history (prognosis) of chronic obstructive pulmonary disease and how it impacts on work performance.

Objectives

Work package 1: to evaluate alternative methods of screening for undiagnosed chronic obstructive pulmonary disease in primary care, with clinical effectiveness and cost-effectiveness analyses and an economic model of a routine screening programme. Work package 2: to recruit a primary care chronic obstructive pulmonary disease cohort, develop a prognostic model [Birmingham Lung Improvement StudieS (BLISS)] to predict risk of respiratory hospital admissions, validate an existing model to predict mortality risk, address some uncertainties about natural history and explore the potential for a home exercise intervention. Work package 3: to identify which factors are associated with employment, absenteeism, presenteeism (working while unwell) and evaluate the feasibility of offering formal occupational health assessment to improve work performance.

Design

Work package 1: a cluster randomised controlled trial with household-level randomised comparison of two alternative case-finding approaches in the intervention arm. Work package 2: cohort study – focus groups. Work package 3: subcohort – feasibility study.

Setting

Primary care settings in West Midlands, UK.

Participants

Work package 1: 74,818 people who have smoked aged 40–79 years without a previous chronic obstructive pulmonary disease diagnosis from 54 general practices. Work package 2: 741 patients with previously diagnosed chronic obstructive pulmonary disease from 71 practices and participants from the work package 1 randomised controlled trial. Twenty-six patients took part in focus groups. Work package 3: occupational subcohort with 248 patients in paid employment at baseline. Thirty-five patients took part in an occupational health intervention feasibility study.

Interventions

Work package 1: targeted case-finding – symptom screening questionnaire, administered opportunistically or additionally by post, followed by diagnostic post-bronchodilator spirometry. The comparator was routine care. Work package 2: twenty-three candidate variables selected from literature and expert reviews. Work package 3: sociodemographic, clinical and occupational characteristics; occupational health assessment and recommendations.

Main outcome measures

Work package 1: yield (screen-detected chronic obstructive pulmonary disease) and cost-effectiveness of case-finding; effectiveness of screening on respiratory hospitalisation and mortality after approximately 4 years. Work package 2: respiratory hospitalisation within 2 years, and barriers to and facilitators of physical activity. Work package 3: work performance – feasibility and acceptability of the occupational health intervention and study processes.

Results

Work package 1: targeted case-finding resulted in greater yield of previously undiagnosed chronic obstructive pulmonary disease than routine care at 1 year [n = 1278 (4%) vs. n = 337 (1%), respectively; adjusted odds ratio 7.45, 95% confidence interval 4.80 to 11.55], and a model-based estimate of a regular screening programme suggested an incremental cost-effectiveness ratio of £16,596 per additional quality-adjusted life-year gained. However, long-term follow-up of the trial showed that at ≈4 years there was no clear evidence that case-finding, compared with routine practice, was effective in reducing respiratory admissions (adjusted hazard ratio 1.04, 95% confidence interval 0.73 to1.47) or mortality (hazard ratio 1.15, 95% confidence interval 0.82 to 1.61). Work package 2: 2305 patients, comprising 1564 with previously diagnosed chronic obstructive pulmonary disease and 741 work package 1 participants (330 with and 411 without obstruction), were recruited. The BLISS prognostic model among cohort participants with confirmed airflow obstruction (n = 1894) included 6 of 23 candidate variables (i.e. age, Chronic Obstructive Pulmonary Disease Assessment Test score, 12-month respiratory admissions, body mass index, diabetes and forced expiratory volume in 1 second percentage predicted). After internal validation and adjustment (uniform shrinkage factor 0.87, 95% confidence interval 0.72 to 1.02), the model discriminated well in predicting 2-year respiratory hospital admissions (c-statistic 0.75, 95% confidence interval 0.72 to 0.79). In focus groups, physical activity engagement was related to self-efficacy and symptom severity. Work package 3: in the occupational subcohort, increasing dyspnoea and exposure to inhaled irritants were associated with lower work productivity at baseline. Longitudinally, increasing exacerbations and worsening symptoms, but not a decline in airflow obstruction, were associated with absenteeism and presenteeism. The acceptability of the occupational health intervention was low, leading to low uptake and low implementation of recommendations and making a full trial unfeasible.

Limitations

Work package 1: even with the most intensive approach, only 38% of patients responded to the case-finding invitation. Management of case-found patients with chronic obstructive pulmonary disease in primary care was generally poor, limiting interpretation of the long-term effectiveness of case-finding on clinical outcomes. Work package 2: the components of the BLISS model may not always be routinely available and calculation of the score requires a computerised system. Work package 3: relatively few cohort participants were in paid employment at baseline, limiting the interpretation of predictors of lower work productivity.

Conclusions

This programme has addressed some of the major uncertainties around screening for undiagnosed chronic obstructive pulmonary disease and has resulted in the development of a novel, accurate model for predicting respiratory hospitalisation in people with chronic obstructive pulmonary disease and the inception of a primary care chronic obstructive pulmonary disease cohort for longer-term follow-up. We have also identified factors that may affect work productivity in people with chronic obstructive pulmonary disease as potential targets for future intervention.

Future work

We plan to obtain data for longer-term follow-up of trial participants at 10 years. The BLISS model needs to be externally validated. Our primary care chronic obstructive pulmonary disease cohort is a unique resource for addressing further questions to better understand the prognosis of chronic obstructive pulmonary disease.

Trial registration

Current Controlled Trials ISRCTN14930255.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 13. See the NIHR Journals Library website for further project information.

Diagnostic sensitivity of impulse oscillometry in early detection of patients exposed to risk factors chronic obstructive pulmonary diseases

Background: Impulse oscillometry (IOS) is a method that does not depend on the cooperation of the patient and can detect small airway diseases with higher sensitivity than spirometry. However, the clinical application value of IOS in the screening of patients exposed to risk factors COPD and early diagnosis remains unclear. The aim of this study is to evaluate diagnostic sensitivity of IOS in the early detection of patients exposed to risk factors COPD.

Methods: A prospective cross-sectional study was conducted in Rasoul Akram Hospital, Tehran, Iran, from 2013 to 2015. 28 patients with COPD risk factors and normal spirometry participated in the study. The IOS was performed. We obtained the respiratory resistance and impedance of 5 Hz (R5) and 20 Hz (R20) and 5 Hz (Z5), respectively. The data were analyzed using SPSS version 17 using Chi-square and two independent sample t-test. Spearman correlation test was used to measure the correlation of oscillometry parameters in the diagnosis of COPD. P-value <0.05 was considered significantfor all statistical analyses.

Results: The mean patient age was 55.50±11.27 years. In this study, the sensitivity of Z5, R5, and R20 was respectively 28.5%, 25%, and 31.5%. All oscillometry parameters were significantly correlated with each other but none of the oscillometry parameters showed significant correlations with FEV1/FVC (rZ5=0.018, rR5=0.082, rR20=0.041 and PZ5=0.932, PR5=0.711, P R20=0.850). According to the results, only 9 patients (32.5%) with normal values of FEV1/FVC had abnormal values of oscillometry.

Conclusion: IOS has a low sensitivity and cannot be used in the screening of early-stage chronic obstructive pulmonary disease.

Characterization of Respiratory Symptoms Among Youth Using Heated Tobacco Products in Hong Kong

IMPORTANCE

Heated tobacco products (HTPs) are promoted as less harmful than combustible cigarettes but epidemiological evidence is scarce, especially in youth.

OBJECTIVE

To investigate the associations of persistent respiratory symptoms with HTP use, cigarette use, and dual use among Hong Kong youth.

DESIGN, SETTING, AND PARTICIPANTS

This was a territorywide cross-sectional school-based survey conducted from October 2018 to July 2019 using an anonymous questionnaire. Schools were randomly invited from a proportionate stratified sample in all 18 districts of Hong Kong. Poisson regression models using generalized estimating equations yielded adjusted prevalence ratios (APRs) of respiratory symptoms in (1) former and current HTP (vs never) users in the whole sample and stratified by cigarette use status and (2) exclusive HTP and dual users vs exclusive cigarette users. Statistical analysis was performed from October 2020 to March 2021.

EXPOSURES

Former and current use of cigarettes, HTPs, e-cigarettes, and other tobacco products.

MAIN OUTCOMES AND MEASURES

Respiratory symptoms for 3 consecutive months in the past 12 months.

RESULTS

The study included 33 627 students with a mean (SD) age of 14.8 (1.9) years; 51.3% (18 171) were boys. Respiratory symptoms were reported by 16.3% (n = 5549) of all students, 29.3% (n = 226) of current users of e-cigarettes, 31.2% (n = 314) of current users of cigarettes, and 33.5% (n = 179) of current users of HTPs. Respiratory symptoms were associated with former (APR, 1.30; 95% CI, 1.06-1.59) and current (APR, 1.59; 95% CI, 1.23-2.06) vs never HTP use and current vs never cigarette use (APR, 1.50; 95% CI, 1.30-1.74) after adjusting for various tobacco use. Associations between respiratory symptoms and current vs never HTP use were observed in never (APR, 1.88; 95% CI, 1.36-2.59) and former (APR, 2.15; 95% CI, 1.12-4.12) cigarette users, but not in current cigarette users (APR, 1.24; 95% CI, 0.97-1.59). Respiratory symptoms were associated with exclusive ever HTP use (APR, 1.46, 95% CI, 1.15-1.86) and ever dual use (APR, 1.29; 95% CI, 1.08-1.54) vs exclusive ever cigarette use. There was no association between exclusive current HTP (vs cigarette) use and respiratory symptoms (1.40; 95% CI, 0.93-2.11).

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that former and current HTP use were associated with persistent respiratory symptoms among youth, especially among never and former cigarette users. Respiratory symptoms were more prevalent in ever exclusive HTP users and ever dual users than ever exclusive cigarette users. These findings suggest that using HTPs instead of cigarettes may not reduce health risks.

Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms

Early identification of subjects running an increased risk of contracting COPD enables focus on individual preventive measures. The slope of the alveolar plateau of the single-breath nitrogen washout test (N2-slope) is a sensitive measure of small-airway dysfunction. However, its role remains unexplored in predicting hospital admission or death related to COPD, i.e. incident COPD events, in relation to the presence of various respiratory symptoms. A random population sample of 625 men, aged 50 (n=218) or 60 years (n=407), was followed for 38 years for incident COPD events. At baseline, a questionnaire on respiratory symptoms and smoking habits was collected, spirometry and the single-breath nitrogen test were performed, and the N2-slope was determined. Proportional hazard regression (Cox regression) analysis was used for the prediction model. The N2-slope improved the prediction of COPD events significantly beyond that of respiratory symptoms weighted all together and other covariates (hazard ratio 1.63, 95% CI 1.20-2.22; p<0.005), a prediction applicable to subjects without (p=0.001) and with (p<0.05) airway obstruction. Dyspnoea and wheezing were the most predictive symptoms. The combination of the N2-slope and number of respiratory symptoms notably resulted in an effective prediction of incident COPD events even in nonobstructive subjects, as evidenced by a predicted incidence of ∼70% and ∼90% for a very steep N2-slope combined with many respiratory symptoms in subject without and with airway obstruction, respectively. The alveolar N2-slope should be considered in the critical need for further research on early diagnosis of COPD.

Natural drug sources for respiratory diseases from Fritillaria: chemical and biological analyses

Fritillaria naturally grows in the temperate region of Northern Hemisphere and mainly distributes in Central Asia, Mediterranean region, and North America. The dried bulbs from a dozen species of this genus have been usually used as herbal medicine, named Beimu in China. Beimu had rich sources of phytochemicals and have extensively applied to respiratory diseases including coronavirus disease (COVID-19). Fritillaria species have alkaloids that act as the main active components that contribute multiple biological activities, including anti-tussive, expectorant, and anti-asthmatic effects, especially against certain respiratory diseases. Other compounds (terpenoids, steroidal saponins, and phenylpropanoids) have also been identified in species of Fritillaria. In this review, readers will discover a brief summary of traditional uses and a comprehensive description of the chemical profiles, biological properties, and analytical techniques used for quality control. In general, the detailed summary reveals 293 specialized metabolites that have been isolated and analyzed in Fritillaria species. This review may provide a scientific basis for the chemical ecology and metabolomics in which compound identification of certain species remains a limiting step.

Cost-effectiveness analysis of COPD screening programs in primary care for high-risk patients in China

We built a decision-analytic model to compare the cost-effectiveness of using portable spirometer and questionnaire to screen chronic obstructive pulmonary diseases (COPD) with no screening (i.e. usual care) among chronic bronchitis patient in China. A lifetime horizon and a payer perspective were adopted. Cost data of health services including spirometry screening and treatment costs covered both maintenance and exacerbation. The result indicated that portable spirometer screening was cost-saving compared with questionnaire screening and no screening, with an incremental cost-effectiveness ratio (ICER) of −5026 and −1766 per QALY, respectively. Sensitivity analyses confirmed the robustness of the results. In summary, portable spirometer screening is likely the optimal option for COPD screening among chronic bronchitis patients China.

Catching "Early" COPD - The Diagnostic Conundrum

Chronic obstructive pulmonary disease (COPD) remains a leading cause of morbidity and mortality worldwide. Despite this, there has been little progress so far in terms of disease-modifying therapies over the last few decades and this is in part due to poor understanding of the definition and mechanisms surrounding early disease before it becomes established and increasingly complex. In this review, the nuances and difficulty in defining early disease in COPD are discussed. There are clear benefits in identifying patients early; however, usually diagnosis is made in the presence of significant lung damage. We consider what can be learned of early disease from COPD studies and highlight the lack of inclusion of young smokers (who may be at risk of COPD) or those with mild disease. We discuss promising clinical measures that are being used in an effort to detect early disease. These include symptom assessment, lung physiology measures and computed tomography (CT) imaging modalities. There is emerging evidence for the role of neutrophils and their proteinases in early COPD. This may form an important biomarker to investigate the pathophysiological processes of early COPD. Given the importance of the early disease, it is recommended that future COPD studies focus on capturing the earliest manifestations of disease, to understand the initiating mechanisms and to identify novel treatment targets.

Prediction of COPD risk accounting for time-varying smoking exposures

RATIONALE

Chronic Obstructive Pulmonary Disease (COPD) is the fourth leading cause of death in the United States. Studies have primarily assessed the relationship between smoking on COPD risk focusing on summary measures, like smoking status.

OBJECTIVE

Develop a COPD risk prediction model incorporating individual time-varying smoking exposures.

METHODS

The Nurses' Health Study (N = 86,711) and the Health Professionals Follow-up Study (N = 39,817) data was used to develop a COPD risk prediction model. Data was randomly split in 50-50 samples for model building and validation. Cox regression with time-varying covariates was used to assess the association between smoking duration, intensity and year-since-quit and self-reported COPD diagnosis incidence. We evaluated the model calibration as well as discriminatory accuracy via the Area Under the receiver operating characteristic Curve (AUC). We computed 6-year risk of COPD incidence given various individual smoking scenarios.

RESULTS

Smoking duration, year-since-quit (if former smokers), sex, and interaction of sex and smoking duration are significantly associated with the incidence of diagnosed COPD. The model that incorporated time-varying smoking variables yielded higher AUCs compared to models using only pack-years. The AUCs for the model were 0.80 (95% CI: 0.74-0.86) and 0.73 (95% CI: 0.70-0.77) for males and females, respectively.

CONCLUSIONS

Utilizing detailed smoking pattern information, the model predicts COPD risk with better accuracy than models based on only smoking summary measures. It might serve as a tool for early detection programs by identifying individuals at high-risk for COPD.

Cost-effectiveness analysis of text messaging to support health advice for smoking cessation

BACKGROUND

Smoking in one of the most serious public health problems. It is well known that it constitutes a major risk factor for chronic diseases and the leading cause of preventable death worldwide. Due to high prevalence of smokers, new cost-effective strategies seeking to increase smoking cessation rates are needed.

METHODS

We performed a Markov model-based cost-effectiveness analysis comparing two treatments: health advice provided by general practitioners and nurses in primary care, and health advice reinforced by sending motivational text messages to smokers' mobile phones. A Markov model was used in which smokers transitioned between three mutually exclusive health states (smoker, former smoker and dead) after 6-month cycles. We calculated the cost-effectiveness ratio associated with the sending of motivational messages. Health care and society perspectives (separately) was adopted. Costs taken into account were direct health care costs and direct health care cost and costs for lost productivity, respectively. Additionally, deterministic sensitivity analysis was performed modifying the probability of smoking cessation with each option.

RESULTS

Sending of text messages as a tool to support health advice was found to be cost-effective as it was associated with increases in costs of €7.4 and €1,327 per QALY gained (ICUR) for men and women respectively from a healthcare perspective, significantly far from the published cost-effectiveness threshold. From a societal perspective, the combined programmed was dominant.

CONCLUSIONS

Sending text messages is a cost-effective approach. These findings support the implantation of the combined program across primary care health centres.

Ambient air pollution exposure and chronic bronchitis in the Lifelines cohort

BACKGROUND

Few large studies have assessed the relationship of long-term ambient air pollution exposure with the prevalence and incidence of symptoms of chronic bronchitis and cough.

METHODS

We leveraged Lifelines cohort data on 132 595 (baseline) and 65 009 (second assessment) participants linked to ambient air pollution estimates. Logistic regression models adjusted for sex, age, educational attainment, body mass index, smoking status, pack-years smoking and environmental tobacco smoke at home were used to assess associations of air pollution with prevalence and incidence of chronic bronchitis (winter cough and sputum almost daily for ≥3 months/year), chronic cough (winter cough almost daily for ≥3 months/year) and prevalence of cough and sputum symptoms, irrespective of duration.

RESULTS

Associations were seen for all pollutants for prevalent cough or sputum symptoms. However, for prevalent and incident chronic bronchitis, statistically significant associations were seen for nitrogen dioxide (NO2) and black carbon (BC) but not for fine particulate matter (PM2.5). For prevalent chronic bronchitis, associations with NO2 showed OR: 1.05 (95% CI: 1.02 to 1.08) and with BC OR: 1.06 (95% CI: 1.03 to 1.09) expressed per IQR; corresponding results for incident chronic bronchitis were NO2 OR: 1.07 (95% CI: 1.02 to 1.13) and BC OR: 1.07 (95% CI: 1.02 to 1.13). In subgroup analyses, slightly stronger associations were observed among women, never smokers and younger individuals.

CONCLUSION

This is the largest analysis to date to examine cross-sectional and longitudinal associations between ambient air pollution and chronic bronchitis. NO2 and BC air pollution was associated with increased odds of prevalent and incident chronic bronchitis.

Is the Symptom of Cough in Chronic Obstructive Pulmonary Disease Important?

Chronic obstructive pulmonary disease (COPD) is a common disease and a significant burden worldwide. The clinical symptoms of this disease include progressive dyspnea, cough, expectoration, and wheezing, among others. At present, the primary focus has been on reducing the frequency of acute exacerbations and improving lung function and dyspnea symptoms, and limited attention has been paid to cough and expectoration symptoms, which may be associated with a decrease in lung function, more acute exacerbations, and hospitalizations. Therefore, this outcomes in patients with COPD.

Estimation of an Exposure Threshold Value for Compensation of Silica-Induced COPD Based on Longitudinal Changes in Pulmonary Function

(1) Background: To estimate the cumulative exposure to respirable crystalline silica (RCS) that reduces lung function to an extent corresponding with airway obstruction equivalent to chronic obstructive pulmonary disease (COPD). (2) Methods: The study is based on a miners' cohort with longitudinal data on lung function and RCS exposure. Random-effects linear regression models, allowing for a possible threshold concerning the exposure concentration were used to analyze the impact of RCS on the ratio of forced expiratory volume in 1 s and forced vital capacity (FEV₁/FVC). The proposed threshold is the amount of RCS resulting in a decrease in FEV₁/FVC from the expected value to the lower limit of normal. (3) Results: The analysis shows that a threshold model fits the data significantly better than the usual linear model. The estimated threshold value for the exposure concentration is 0.089 mg/m³. Using this threshold, the estimate for the corresponding reference dose for RCS is 2.33 mg/m³·y. (4) Conclusions: The analysis confirmed that RCS has a negative impact on lung function. The effect is primarily due to exposure above a concentration threshold of 0.1 mg/m³. It is recommended that COPD should be compensated as an occupational disease if cumulative exposure was at least 2 mg/m³·y above this threshold.

Decreased COPD prevalence in Sweden after decades of decrease in smoking

BACKGROUND

COPD has increased in prevalence worldwide over several decades until the first decade after the millennium shift. Evidence from a few recent population studies indicate that the prevalence may be levelling or even decreasing in some areas in Europe. Since the 1970s, a substantial and ongoing decrease in smoking prevalence has been observed in several European countries including Sweden. The aim of the current study was to estimate the prevalence, characteristics and risk factors for COPD in the Swedish general population. A further aim was to estimate the prevalence trend of COPD in Northern Sweden from 1994 to 2009.

METHODS

Two large random population samples were invited to spirometry with bronchodilator testing and structured interviews in 2009-2012, one in south-western and one in northern Sweden, n = 1839 participants in total. The results from northern Sweden were compared to a study performed 15 years earlier in the same area and age-span. The diagnosis of COPD required both chronic airway obstruction (CAO) and the presence of respiratory symptoms, in line with the GOLD documents since 2017. CAO was defined as post-bronchodilator FEV1/FVC < 0.70, with sensitivity analyses based on the FEV1/FVC < lower limit of normal (LLN) criterion.

RESULTS

Based on the fixed ratio definition, the prevalence of COPD was 7.0% (men 8.3%; women 5.8%) in 2009-2012. The prevalence of moderate to severe (GOLD ≥ 2) COPD was 3.5%. The LLN based results were about 30% lower. Smoking, occupational exposures, and older age were risk factors for COPD, whereof smoking was the most dominating risk factor. In northern Sweden the prevalence of COPD, particularly moderate to severe COPD, decreased significantly from 1994 to 2009, and the decrease followed a decrease in smoking.

CONCLUSIONS

The prevalence of COPD has decreased in Sweden, and the prevalence of moderate to severe COPD was particularly low. The decrease follows a major decrease in smoking prevalence over several decades, but smoking remained the dominating risk factor for COPD.

Diagnosis and Treatment of Early Chronic Obstructive Lung Disease (COPD)

Chronic obstructive lung disease (COPD) is responsible for substantial rates of mortality and economic burden, and is one of the most important public-health concerns. As the disease characteristics include irreversible airway obstruction and progressive lung function decline, there has been a great deal of interest in detection at the early stages of COPD during the “at risk” or undiagnosed preclinical stage to prevent the disease from progressing to the overt stage. Previous studies have used various definitions of early COPD, and the term mild COPD has also often been used. There has been a great deal of recent effort to establish a definition of early COPD, but comprehensive evaluation is still required, including identification of risk factors, various physiological and radiological tests, and clinical manifestations for diagnosis of early COPD, considering the heterogeneity of the disease. The treatment of early COPD should be considered from the perspective of prevention of disease progression and management of clinical deterioration. There has been a lack of studies on this topic as the definition of early COPD has been proposed only recently, and therefore further clinical studies are needed.

Bronchial Rheoplasty for Treatment of Chronic Bronchitis. Twelve-Month Results from a Multicenter Clinical Trial

Rationale: Chronic bronchitis (CB) is characterized by productive cough with excessive mucus production, resulting in quality-of-life impairment and increased exacerbation risk. Bronchial rheoplasty uses an endobronchial catheter to apply nonthermal pulsed electrical fields to the airways. Preclinical studies have demonstrated epithelial ablation followed by regeneration of normalized epithelium.Objectives: To evaluate the feasibility, safety, and initial outcomes of bronchial rheoplasty in patients with CB.Methods: Pooled analysis of two separate studies enrolling 30 patients undergoing bilateral bronchial rheoplasty was conducted. Follow-up through 6 months (primary outcome) and 12 months included assessment of adverse events, airway histology, and changes in symptoms using the Chronic Obstructive Pulmonary Disease (COPD) Assessment Test and St. George's Respiratory Questionnaire (SGRQ).Measurements and Main Results: Bronchial rheoplasty was performed in all 30 patients (63% male; mean [SD] age, 67 [7.4]; mean [SD] postbronchodilator FEV1, 65% [21%]; mean [SD] COPD Assessment Test score 25.6 [7.1]; mean [SD] SGRQ score, 59.6 [15.3]). There were no device-related and four procedure-related serious adverse events through 6 months, and there were none thereafter through 12 months. The most frequent nonserious, device- and/or procedure-related event through 6 months was mild hemoptysis in 47% (14 of 30) patients. Histologically, the mean goblet cell hyperplasia score was reduced by a statistically significant amount (P < 0.001). Significant changes from baseline to 6 months in COPD Assessment Test (mean, -7.9; median, -8.0; P = 0.0002) and SGRQ (mean, -14.6; median, -7.2; P = 0.0002) scores were observed, with similar observations through 12 months.Conclusions: This study provides the first clinical evidence of the feasibility, safety, and initial outcomes of bronchial rheoplasty in symptomatic patients with CB.Clinical trial registered with www.anzctr.org.au (ACTRN 12617000330347) and clinicaltrials.gov (NCT03107494).

Association of Nonobstructive Chronic Bronchitis With Respiratory Health Outcomes in Adults

IMPORTANCE

Chronic bronchitis has been associated with cigarette smoking as well as with e-cigarette use among young adults, but the association of chronic bronchitis in persons without airflow obstruction or clinical asthma, described as nonobstructive chronic bronchitis, with respiratory health outcomes remains uncertain.

OBJECTIVE

To assess whether nonobstructive chronic bronchitis is associated with adverse respiratory health outcomes in adult ever smokers and never smokers.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included 22 325 adults without initial airflow obstruction (defined as the ratio of forced expiratory volume in the first second [FEV1] to forced vital capacity [FVC] of <0.70) or clinical asthma at baseline. The National Heart, Lung, and Blood Institute (NHLBI) Pooled Cohorts Study harmonized and pooled data from 9 US general population-based cohorts. Thus present study is based on data from 5 of these cohorts. Participants were enrolled from August 1971 through May 2007 and were followed up through December 2018.

EXPOSURES

Nonobstructive chronic bronchitis was defined by questionnaire at baseline as both cough and phlegm for at least 3 months for at least 2 consecutive years.

MAIN OUTCOMES AND MEASURES

Lung function was measured by prebronchodilator spirometry. Hospitalizations and deaths due to chronic lower respiratory disease and respiratory disease-related mortality were defined by events adjudication and administrative criteria. Models were stratified by smoking status and adjusted for anthropometric, sociodemographic, and smoking-related factors. The comparison group was participants without nonobstructive chronic bronchitis.

RESULTS

Among 22 325 adults included in the analysis, mean (SD) age was 53.0 (16.3) years (range, 18.0-95.0 years), 58.2% were female, 65.9% were non-Hispanic white, and 49.6% were ever smokers. Among 11 082 ever smokers with 99 869 person-years of follow-up, participants with nonobstructive chronic bronchitis (300 [2.7%]) had accelerated decreases in FEV1 (4.1 mL/y; 95% CI, 2.1-6.1 mL/y) and FVC (4.7 mL/y; 95% CI, 2.2-7.2 mL/y), increased risks of chronic lower respiratory disease-related hospitalization or mortality (hazard ratio [HR], 2.2; 95% CI, 1.7-2.7), and greater respiratory disease-related (HR, 2.0; 95% CI, 1.1-3.8) and all-cause mortality (HR, 1.5; 95% CI, 1.3-1.8) compared with ever smokers without nonobstructive chronic bronchitis. Among 11 243 never smokers with 120 004 person-years of follow-up, participants with nonobstructive chronic bronchitis (151 [1.3%]) had greater rates of chronic lower respiratory disease-related hospitalization or mortality (HR, 3.1; 95% CI, 2.1-4.5) compared with never smokers without nonobstructive chronic bronchitis. Nonobstructive chronic bronchitis was not associated with FEV1:FVC decline or incident airflow obstruction. The presence of at least 1 of the component symptoms of nonobstructive chronic bronchitis (ie, chronic cough or phlegm), which was common in both ever smokers (11.0%) and never smokers (6.7%), was associated with adverse respiratory health outcomes.

CONCLUSIONS AND RELEVANCE

The findings suggest that nonobstructive chronic bronchitis is associated with adverse respiratory health outcomes, particularly in ever smokers, and may be a high-risk phenotype suitable for risk stratification and targeted therapies.

Chronic Cough and Phlegm in Subjects Undergoing Comprehensive Health Examination in Japan - Survey of Chronic Obstructive Pulmonary Disease Patients Epidemiology in Japan (SCOPE-J)

Purpose

The purpose of this study was to estimate the prevalence of subjects with chronic cough and phlegm and describe their characteristics including the presence or absence of airflow limitation among the general population in Japan.

Subjects and Methods

This was an observational cross-sectional survey targeting multiple regions of Japan. Subjects aged 40 years or above who were undergoing comprehensive health examination were recruited. The existence of chronic cough and phlegm, airflow limitation, and treatment for respiratory diseases were examined. Chronic cough and phlegm were defined as having both symptoms for at least 3 months of the year and for at least 2 consecutive years, or as receiving any treatment for chronic bronchitis at the time of recruitment. Airflow limitation was defined as forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) less than 0.7.

Results

In a total of 22,293 subjects, 380 subjects (1.7%) had chronic cough and phlegm. Among these 380 subjects, 21.8% received treatment for a respiratory disease, and 11.6% had airflow limitation. Compared to subjects without both chronic cough and phlegm but with airflow limitation, subjects with chronic cough and phlegm without airflow limitation were younger, more likely to be current smokers (39.6%), and had higher total scores on a chronic obstructive pulmonary disease (COPD) assessment test (CAT). Scores of CAT questions 1-4 (cough, phlegm, chest tightness, breathlessness, respectively) were higher in subjects with chronic cough and phlegm regardless of airflow limitation.

Conclusion

This study demonstrated that subjects identified to have chronic cough and phlegm in comprehensive health examination settings were symptomatic, while most of them did not receive any treatment for respiratory diseases and did not have airflow limitation. Screening subjects for chronic cough and phlegm in a comprehensive health examination followed by a detailed examination of screened subjects could be an effective approach for better management of chronic cough and phlegm. Smoking cessation should be included in the management, in consideration that around 40% of subjects with chronic cough and phlegm were current smokers.