The association of blood eosinophil counts and FEV1 decline: a cohort study

BACKGROUND

Accelerated lung function decline is characteristic of chronic obstructive pulmonary disease (COPD). However, the association between blood eosinophil counts and lung function decline, accounting for current smoking status, in young individuals without prevalent lung disease is not fully understood.

METHODS

This is a cohort study of 629 784 Korean adults without COPD or a history of asthma at baseline who participated in health screening examinations including spirometry and differential white blood cell counts. We used linear mixed effects model to estimate the annual change in FEV1 (mL) by baseline blood eosinophil count, adjusting for covariates including smoking status. We also performed a stratified analysis by baseline and time-varying smoking status.

RESULTS

During a mean follow-up of 6.5 years (maximum of 17.8 years), the annual change in FEV1 (95% confidence interval [CI]) in participants with eosinophil counts <100, 100-199, 200-299, 300-499, and ≥500 cells/µL in the fully adjusted model were -23.3 (-23.9, -22.7), -24.3 (-24.9, -23.7), -24.8 (-25.5, -24.2), -25.5 (-26.2, -24.8), and -26.8 (-27.7, -25.9) mL, respectively. When stratified by smoking status, participants with higher eosinophil count had a faster decline in FEV1 than those with lower eosinophil count in both never- and ever-smokers, which persisted when time-varying smoking status was used.

CONCLUSIONS

Blood eosinophil counts were associated with a faster lung function decline among healthy individuals without lung disease, independent of smoking status. The findings suggest that blood eosinophil counts contribute to the risk of faster lung function decline, particularly among younger adults without a history of lung disease.

Longitudinal BMI change and outcomes in Chronic Obstructive Pulmonary Disease: a nationwide population-based cohort study

BACKGROUND

The association between longitudinal body mass index (BMI) change and clinical outcomes in patients with chronic obstructive pulmonary disease (COPD) has not fully investigated.

METHODS

This retrospective cohort study included 116,463 COPD patients aged ≥ 40, with at least two health examinations, one within 2 years before and another within 3 years after COPD diagnosis (January 1, 2014, to December 31, 2019). Associations between BMI percentage change with all-cause mortality, primary endpoint, and initial severe exacerbation were assessed.

RESULTS

BMI decreased > 5% in 14,728 (12.6%), while maintained in 80,689 (69.2%), and increased > 5% in 21,046 (18.1%) after COPD diagnosis. Compared to maintenance group, adjusted hazard ratio (aHR) for all-cause mortality was 1.70 in BMI decrease group (95% CI:1.61, 1.79) and 1.13 in BMI increase group (95% CI:1.07, 1.20). In subgroup analysis, decrease in BMI showed a stronger effect on mortality as baseline BMI was lower, while an increase in BMI was related to an increase in mortality only in obese COPD patients with aHRs of 1.18 (95% CI: 1.03, 1.36). The aHRs for the risk of severe exacerbation (BMI decrease group and increase group vs. maintenance group) were 1.30 (95% CI:1.24, 1.35) and 1.12 (95% CI:1.07, 1.16), respectively.

CONCLUSIONS

A decrease in BMI was associated with an increased risk of all-cause mortality in a dose-dependent manner in patients with COPD. This was most significant in underweight patients. Regular monitoring for weight loss might be an important component for COPD management.

Impact of smoking reduction on lung cancer risk in patients with COPD who smoked fewer than 30 pack-years: a nationwide population-based cohort study

BACKGROUND

The effects of smoking reduction on the incidence of lung cancer in patients with chronic obstructive pulmonary disease (COPD) are not well known. This study aimed to investigate the effects of changes in smoking habits after COPD diagnosis on lung cancer development in patients who smoked less than 30 pack-years.

METHODS

This nationwide retrospective cohort study included 16,832 patients with COPD who smoked less than 30 pack-years at the time of COPD diagnosis. Based on changes in smoking habits in the health screening examination data, smokers were categorized into three groups: quitters, reducers, and sustainers. The primary outcome was the risk of lung cancer development, which was estimated using the Cox proportional hazards model. We also modelled the amount of smoking reduction as a continuous variable.

RESULTS

During a median follow-up of 4 years, the cumulative incidence of lung cancer was the highest among sustainers, followed by reducers and quitters. Compared with sustainers, reducers (adjusted HR 0.74, 95% CI:0.56-0.98) and quitters (adjusted HR 0.78, 95% CI:0.64-0.96) had a significantly lower risk of lung cancer. Incidence of lung cancer showed a decreasing trend with a decreasing amount of smoking (P for linearity < 0.01).

CONCLUSIONS

In patients with COPD who smoked less than 30 pack-years, smoking reduction and cessation lowered the risk of lung cancer.

Association of resistance training and moderate-to-vigorous physical activity with clinical outcomes in men with airflow limitation: a nationwide population-based study

Aerobic moderate-to-vigorous physical activity (MVPA) is recommended for individuals with chronic diseases. However, the association between resistance training (RT) in addition to moderate to vigorous physical activity (MVPA) and sleep duration, as well as respiratory symptoms, in patients with chronic obstructive pulmonary disease has not been thoroughly investigated. This population-based cross-sectional study used data from the Korea National Health and Nutrition Examination Survey between 2014 and 2019. A total of 61,754 individuals were identified and men with airflow limitation (FEV1/FVC < 0.7) who engaged in aerobic MVPA were selected (n = 794). Weighted percentages and odds ratio (OR) of sleep problems (≤ 5 or ≥ 9 h), chronic cough, and chronic sputum were estimated. A multivariate-adjusted complex sample logistic regression model was used to calculate ORs and 95% confidence intervals (CI). Subgroup analyses were conducted using the forced expiratory volume (FEV1) % of the predicted value (%pred) ≥ 80 vs. < 80. The percentages of sleep problems, chronic cough, and chronic sputum production were lower in men who underwent aerobic MVPA + RT than in those who underwent aerobic MVPA alone. The multivariable-adjusted OR of sleep problems was 0.44 (95% CI 0.25-0.77) in individuals undergoing aerobic MVPA + RT compared to aerobic MVPA alone. The ORs of chronic cough and sputum were 0.35 (95% CI 0.13-0.94) and 0.51 (95% CI 0.30-0.87), respectively. These associations were only significant in individuals with FEV1 < 80% pred. Compared with aerobic MVPA alone, aerobic MVPA + RT was associated with appropriate sleep duration and a decrease in chronic cough and sputum in male with airflow limitation. This was more pronounced in individuals with a FEV1 < 80% pred.

Preoperative DLco and FEV1 are correlated with postoperative pulmonary complications in patients after esophagectomy

Limited information is available regarding the association between preoperative lung function and postoperative pulmonary complications (PPCs) in patients with esophageal cancer who undergo esophagectomy. This is a retrospective cohort study. Patients were classified into low and high lung function groups by the cutoff of the lowest fifth quintile of forced expiratory volume in 1 s (FEV1) %predicted (%pred) and diffusing capacity of the carbon monoxide (DLco) %pred. The PPCs compromised of atelectasis requiring bronchoscopic intervention, pneumonia, and acute lung injury/acute respiratory distress syndrome. Modified multivariable-adjusted Poisson regression model using robust error variances and inverse probability treatment weighting (IPTW) were used to assess the relative risk (RR) for the PPCs. A joint effect model considered FEV1%pred and DLco %pred together for the estimation of RR for the PPCs. Of 810 patients with esophageal cancer who underwent esophagectomy, 159 (19.6%) developed PPCs. The adjusted RR for PPCs in the low FEV1 group relative to high FEV1 group was 1.48 (95% confidence interval [CI] = 1.09-2.00) and 1.98 (95% CI = 1.46-2.68) in the low DLco group relative to the high DLco group. A joint effect model showed adjusted RR of PPCs was highest in patients with low DLco and low FEV1 followed by low DLco and high FEV1, high DLco and low FEV1, and high DLco and high FEV1 (Reference). Results were consistent with the IPTW. Reduced preoperative lung function (FEV1 and DLco) is associated with post-esophagectomy PPCs. The risk was further strengthened when both values decreased together.

Lack of association between Inhaled Corticosteroid use based on the Exhaled Nitric Oxide and Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Background

Fractional exhaled nitric oxide (FeNO) is known to useful biomarker for detecting eosinophilic airway inflammation. However, there is a lack of evidence regarding the role of FeNO in chronic obstructive pulmonary disease (COPD). We aimed to assess whether elevated FeNO and its impact on treatment change into an inhaled corticosteroid (ICS)-containing regimen and association with acute exacerbation (AE) in patients with COPD.

Methods

We retrospectively analyzed 107 COPD patients without history of asthma from March 2016 to December 2019. The patients whose FeNO value was more than 50 parts per billion [ppb] were defined into the high FeNO group. Multivariable analysis with logistic regression was used to identify factors associated with AE in COPD.

Results

The median FeNO value was 32 (Interquartile range [IQR], 19-45) ppb, and 34 (20.0%) patients were classified as high FeNO group (median 74ppb). In the high FeNO group, changes in inhaler treatment into an ICS-containing regimen occurred in 23 of 34 patients after the measurement of FeNO. In multivariate analysis, high FeNO was not a contributing factor for AE, but only the high blood eosinophil count (≥ 300 cells/µL) was associated with AE (adjusted odds ratio, 2.63; 95% confidence interval, 1.01-6.91; p = 0.049).

Conclusions

High FeNO value had a significant impact on the prescription of ICSs in COPD patients, but it did not show a significant association with AE either on its own or with changes in treatment.

Usefulness of cardiopulmonary exercise test combined with exercise stress echocardiography in mild chronic thromboembolic pulmonary disease

PURPOSE

Chronic thromboembolic pulmonary disease (CTEPD) can lead to exercise limitations even without right ventricular (RV) dysfunction or pulmonary hypertension at rest. Combining exercise stress echocardiography with cardiopulmonary exercise testing (ESE-CPET) for RV function and pressure changes combined measuring overall function may be useful for CTEPD evaluation. This study aims to investigate CPET and ESE results to elucidate the mechanisms of exercise limitation in mild CTEPD cases.

METHODS

Among our CTEPD registry, 50 patients who performed both right heart catheterization data of mild disease (less than 30 mm Hg of mean pulmonary arterial pressure (mPAP)) and ESE-CPET were enrolled. Echocardiography and CPET-derived parameters were compared with hemodynamic parameters measured through right heart catheterization.

RESULTS

Peak VO2 (maximal oxygen consumption) was decreased in overall population (71.3 ± 16.3% of predictive value). Peak VO2 during exercise was negatively correlate with mPAP and pulmonary vascular resistance at rest. A substantial increase in RV systolic pressure (RVSP) was observed during exercise (RVSP: pre-exercise 37.2 ± 11.8 mm Hg, postexercise 64.3 ± 24.9 mm Hg, p-value < .001). Furthermore, RV function deteriorated during exercise when compared to the baseline (RV fractional area change: 31.5 ± 10.0% to 37.8 ± 7.0%, p-value < .001; RV global longitudinal strain: -17.1 ± 4.2% to -17.7 ± 3.3%, p-value < .001) even though basal RV function was normal. While an excessive increase in RVSP during exercise was noticed in both groups, dilated RV and RV dysfunction during exercise were demonstrated only in the impaired exercise capacity group.

CONCLUSION

CTEPD patients with mild PH or without PH exhibited limited exercise capacity alongside an excessive increase in RVSP during exercise. Importantly, RV dysfunction during exercise was significantly associated with exercise capacity. ESE-CPET could aid in comprehending the primary cause of exercise limitation in these patients.

Prospective study investigating hypofractionated proton beam therapy in patients with inoperable early stage non-small cell lung cancer

Purpose

To report the results of hypofractionated proton beam therapy (PBT) for the treatment of early stage lung cancer in patients not suitable for surgical resection.

Methods

Data from 27 adult patients, who were diagnosed with inoperable cT1-3N0 non-small cell lung cancer (NSCLC) between March 2018 and August 2020, were analyzed. PBT was prescribed as 64 Cobalt Grey equivalents delivered in 8 fractions (Sumitomo, Japan). The primary endpoint was local control; secondary endpoints included overall survival, quality of life, and grade ≥3 toxicity.

Results

The median follow-up was 28.9 months (range, 1.1-62.1 months). During follow-up, 13 (48.1%) patients experienced disease progression, including local progression in 7. Two-year local control rates were 73.5%, 85.7% for T1, and 61.4% for T2-3. The worse local control rate was observed in those with large clinical target volumes (≥ 47.5 cc) and heavy smoking history (≥30 pack-years). The two-year overall survival rate was 76.5%. Grade 3 radiation-related toxicities were observed in 2 (7.4%) patients. In the European Organization for Research and Treatment of Cancer Quality of Life Core 30 results, the global score did not change significantly from baseline. However, dyspnea score increased from 19.8 before PBT to 33.3 at 4 months' post-PBT (p=0.047) and was maintained until 13 months (p=0.028).

Conclusion

Hypofractionated PBT was a safe treatment option for inoperable early stage NSCLC and appeared to be appropriate for small tumor volumes. However, local control for larger tumors requires further improvement.

Machine learning model for circulating tumor DNA detection in chronic obstructive pulmonary disease patients with lung cancer

Background

Patients with chronic obstructive pulmonary disease (COPD) have a high risk of developing lung cancer. Due to the high rates of complications from invasive diagnostic procedures in this population, detecting circulating tumor DNA (ctDNA) as a non-invasive method might be useful. However, clinical characteristics that are predictive of ctDNA mutation detection remain incompletely understood. This study aimed to investigate factors associated with ctDNA detection in COPD patients with lung cancer.

Methods

Herein, 177 patients with COPD and lung cancer were prospectively recruited. Plasma ctDNA was genotyped using targeted deep sequencing. Comprehensive clinical variables were collected, including the emphysema index (EI), using chest computed tomography. Machine learning models were constructed to predict ctDNA detection.

Results

At least one ctDNA mutation was detected in 54 (30.5%) patients. After adjustment for potential confounders, tumor stage, C-reactive protein (CRP) level, and milder emphysema were independently associated with ctDNA detection. An increase of 1% in the EI was associated with a 7% decrease in the odds of ctDNA detection (adjusted odds ratio =0.933; 95% confidence interval: 0.857-0.999; P=0.047). Machine learning models composed of multiple clinical factors predicted individuals with ctDNA mutations at high performance (AUC =0.774).

Conclusions

ctDNA mutations were likely to be observed in COPD patients with lung cancer who had an advanced clinical stage, high CRP level, or milder emphysema. This was validated in machine learning models with high accuracy. Further prospective studies are required to validate the clinical utility of our findings.

Predictive Role of White Blood Cell Differential Count for the Development of Acute Exacerbation in Korean Chronic Obstructive Pulmonary Disease

Purpose

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by chronic inflammation. Acute exacerbation of COPD (AECOPD) manifests as acute worsening of respiratory symptoms and is associated with high morbidity and mortality. The aim of the present study was to evaluate the predictive value of white blood count (WBC) and its derived inflammatory biomarkers for AECOPD.

Methods

From the Korean COPD Subgroup Study cohort, a prospective and multicenter observational study, 826 patients who had baseline complete blood count (CBC) and 3-year AECOPD data were included. Follow-up CBC data at 1 (n = 385), 2 (n = 294), and 3 (n = 231) years were collected for available patients. The primary outcome was the occurrence of AECOPD at 3 years. The risk of AECOPD was evaluated using a binary logistic analysis.

Results

The cumulative incidences of 12-, 24-, and 36-month AECOPD were 47.6%, 60.5%, and 67.6%, respectively. Patients with AECOPD at 3 years had higher baseline WBC counts, neutrophil counts, neutrophil/lymphocyte ratio (NLR), and neutrophil/monocyte ratio than those without AECOPD. Higher WBC count, neutrophil count, and NLR were associated with the 3-year occurrence of AECOPD in the univariate analysis, but only the higher neutrophil count was a significant risk factor (odds ratio [OR] = 1.468; 95% confidence interval [CI]: 1.024-2.104) in the covariates-adjusted analysis. In the analysis of changes in inflammatory parameters, a decrease in the platelet count (OR = 0.502; 95% CI: 0.280-0.902) and NLR (OR = 0.535; 95% CI: 0.294-0.974) at 2 years and an increase in the eosinophil count (OR = 2.130; 95% CI: 1.027-4.416) at 3 years were significantly associated with AECOPD in the adjusted analysis.

Conclusion

Our data suggest that a high baseline WBC count, particularly neutrophil count, was associated with a higher incidence of long-term AECOPD.

Association Between Regular Moderate to Vigorous Physical Activity Initiation Following COPD Diagnosis and Mortality: An Emulated Target Trial Using Nationwide Cohort Data

BACKGROUND

Moderate to vigorous physical activity (MVPA) in patients with COPD affects their overall health outcomes, including symptom relief and improved quality of life. However, the magnitude of the effect of MVPA initiation on real-world clinical outcomes has not been well investigated.

RESEARCH QUESTION

How does MVPA initiation affect mortality and severe exacerbation in patients who have not engaged in MVPA prior to COPD diagnosis?

STUDY DESIGN AND METHODS

This study included patients with COPD aged ≥ 40 years who were not performing MVPA prior to COPD diagnosis and who had at least one health screening visit prior to and following their COPD diagnosis between January 1, 2010, and December 31, 2018. The main exposure was MVPA, defined as vigorous aerobic exercise > 20 min per day on ≥ 3 days per week or moderate aerobic exercise > 30 min per day on ≥ 5 days per week. The primary end point was all-cause mortality, and the secondary end point was initial severe exacerbation as the time to event following COPD diagnosis.

RESULTS

In total, 110,097 person-trials were included (27,564 MVPA increases and 82,533 control groups). No differences were observed between the covariates following matching. The adjusted hazards ratio of all-cause mortality for the MVPA group compared with the control group was 0.84 (95% CI, 0.79-0.89). In the subgroup analysis, patients aged > 65 years, female patients, those who had never smoked, and patients with a higher Charlson Comorbidity Index score displayed a stronger effect of MVPA on reducing mortality than younger male patients, those who had ever smoked, and patients with a lower Charlson Comorbidity Index score (Pinteraction < .05). The fully adjusted hazards ratio for the risk of severe exacerbation (MVPA group vs control) was 0.90 (95% CI, 0.87-0.94).

INTERPRETATION

Initiation of MVPA can potentially reduce mortality and severe exacerbations in patients with COPD, although personalized interventions and further clinical trials are necessary.

Impact of preserved ratio impaired spirometry on coronary artery calcium score progression: a longitudinal cohort study

Background

Preserved ratio impaired spirometry (PRISm) is associated with increased cardiovascular disease (CVD) risk and mortality. However, a causal relationship between PRISm and CVD remains unclear. We investigated the progression of coronary artery calcium (CAC) scores based on the presence of PRISm and reduced forced vital capacity (FVC).

Methods

This retrospective cohort study included 11 420 participants aged ≥40 years with forced expiratory volume in 1 s (FEV1)/FVC ≥0.7 who underwent at least two health screening examinations with coronary computed tomography scan between 2003 and 2020, and were without a history of CVD or interstitial lung disease. Participants with PRISm, defined as FEV1/FVC ≥0.7 and FEV1 <80% predicted, were further divided by low FVC (FVC <80% predicted). We estimated the 5-year progression rates of CAC by comparing participants with and without PRISm at baseline using mixed linear models.

Results

Of the 11 420 participants, 8536 (75%), 811 (7%) and 2073 (18%) had normal spirometry, PRISm with normal FVC and PRISm with low FVC, respectively. During the mean (range) follow-up of 6.0 (0.5-17.2) years, the multivariable adjusted ratio of 5-year CAC progression rates comparing participants with PRISm to those with normal spirometry was 1.08 (95% CI 1.04-1.13). This rate was higher in participants with PRISm with low FVC (1.21 (95% CI 1.12-1.30)) than in those with normal FVC.

Conclusion

In this longitudinal cohort study of subjects without a history of CVD, PRISm was significantly associated with CAC progression, which was more evident in the group with PRISm and low FVC.

Factors associated with failure of cardiopulmonary function recovery after lung cancer surgery

BACKGROUND AND OBJECTIVE

This study aimed to evaluate the longitudinal changes in cardiopulmonary function (CPF) and identify predictors of cardiopulmonary recovery failure after lung cancer surgery.

METHODS

Data was obtained from a prospective CATCH-LUNG cohort study, where patients were divided into two groups based on 6-min walk distance (6MWD) at baseline and 6 months after surgery. CPF recovery failure was defined as a participant whose 6MWD dropped over 50 m from baseline to 6 months after surgery. Patients with a baseline 6MWD less than 400 m were excluded. The analysis was investigated using mixed effects models, and the relative estimates for the predictors were expressed relative risk (RR) and 95% CI using a Poisson regression.

RESULTS

Among 419 patients, 24.1% and 17.7% showed failure of CPF recovery at 6 months and 1 year after surgery, respectively. In the multivariable analysis, baseline step count [RR per 1000 steps lower = 1.05 (95% CI, 1.01-1.09)], baseline dyspnoea [RR per 10 points higher = 1.15(1.07-1.23)], decreased FEV1 % predicted from baseline to 2 weeks after surgery [RR per 10% lower = 1.30(1.10-1.53)] and decreased moderate-to-vigorous physical activity (MVPA) from baseline to 2 weeks [RR = 1.95(1.22, 3.11)] or persistent low MVPA at baseline and 2 weeks after surgery [RR = 1.63(1.04, 2.54)] were significant factors for loss of CPF.

CONCLUSION

The inability to recover CPF at 6 months after surgery was linked to reduction of lung function and MVPA from baseline to 2 weeks as well as baseline physical activity (PA) and dyspnoea. These results imply that engagement of perioperative PA is necessary to facilitate recovery of CPF after lung cancer surgery.

International expert consensus on diagnosis and treatment of lung cancer complicated by chronic obstructive pulmonary disease

Background

Lung cancer combined by chronic obstructive pulmonary disease (LC-COPD) is a common comorbidity and their interaction with each other poses significant clinical challenges. However, there is a lack of well-established consensus on the diagnosis and treatment of LC-COPD.

Methods

A panel of experts, comprising specialists in oncology, respiratory medicine, radiology, interventional medicine, and thoracic surgery, was convened. The panel was presented with a comprehensive review of the current evidence pertaining to LC-COPD. After thorough discussions, the panel reached a consensus on 17 recommendations with over 70% agreement in voting to enhance the management of LC-COPD and optimize the care of these patients.

Results

The 17 statements focused on pathogenic mechanisms (n=2), general strategies (n=4), and clinical application in COPD (n=2) and lung cancer (n=9) were developed and modified. These statements provide guidance on early screening and treatment selection of LC-COPD, the interplay of lung cancer and COPD on treatment, and considerations during treatment. This consensus also emphasizes patient-centered and personalized treatment in the management of LC-COPD.

Conclusions

The consensus highlights the need for concurrent treatment for both lung cancer and COPD in LC-COPD patients, while being mindful of the mutual influence of the two conditions on treatment and monitoring for adverse reactions.

Intraoperative Factors Modifying the Risk of Postoperative Pulmonary Complications After Living Donor Liver Transplantation

BACKGROUND

The relationship between intraoperative anesthetic management and postoperative pulmonary complications (PPCs) after liver transplantation is not fully understood. We aimed to determine the intraoperative contributors to PPC.

METHODS

The retrospectively collected cohort included 605 patients who underwent living donor liver transplantation. PPCs comprised respiratory failure, respiratory infection, pulmonary edema, atelectasis (at least moderate degree), pneumothorax, and pleural effusion (at least moderate degree). The presence and type of PPC were evaluated by 2 pulmonary physicians. Logistic regression analysis was performed to determine the association between perioperative variables and PPC risk.

RESULTS

Of the 605 patients, 318 patients (52.6%) developed 486 PPCs. Multivariable analysis demonstrated that PPC risk decreased with low tidal volume ventilation (odds ratio [OR] 0.62 [0.41-0.94], P  = 0.023) and increased with greater driving pressure at the end of surgery (OR 1.08 [1.01-1.14], P  = 0.018), prolonged hypotension (OR 1.85 [1.27-2.70], P  = 0.001), and blood albumin level ≤3.0 g/dL at the end of surgery (OR 2.43 [1.51-3.92], P  < 0.001). Survival probability at 3, 6, and 12 mo after transplantation was 91.2%, 89.6%, and 86.5%, respectively, in patients with PPCs and 98.3%, 96.5%, and 93.4%, respectively, in patients without PPCs (hazard ratio 2.2 [1.3-3.6], P  = 0.004). Graft survival probability at 3, 6, and 12 mo after transplantation was 89.3%, 87.1%, and 84.3%, respectively, in patients with PPCs and 97.6%, 95.8%, and 92.7%, respectively, in patients without PPCs (hazard ratio 2.3 [1.4-3.7], P  = 0.001).

CONCLUSIONS

We found that tidal volume, driving pressure, hypotension, and albumin level during living donor liver transplantation were significantly associated with PPC risk. These data may help determine patients at risk of PPC or develop an intraoperative lung-protective strategy for liver transplant recipients.

Air pollution and mortality in patients with chronic obstructive pulmonary disease: a cohort study in South Korea

Background

Evidence on whether long-term exposure to air pollution increases the mortality risk in patients with chronic obstructive pulmonary disease (COPD) is limited.

Objectives

We aimed to investigate the associations of long-term exposure to particulate matter with diameter <10 µm (PM10) and nitrogen dioxide (NO2) with overall and disease-specific mortality in COPD patients.

Design

We conducted a nationwide retrospective cohort study of 121,423 adults ⩾40 years diagnosed with COPD during 1 January to 31 December 2009.

Methods

Exposure to PM10 and NO2 was estimated for residential location using the ordinary kriging method. We estimated the risk of overall mortality associated with 1-, 3-, and 5-years average concentrations of PM10 and NO2 using Cox proportional hazards models and disease-specific mortality using the Fine and Gray method adjusted for age, sex, income, body mass index, smoking, comorbidities, and exacerbation history.

Results

The adjusted hazard ratios (HRs) for overall mortality associated with a 10 µg/m3 increase in 1-year PM10 and NO2 exposures were 1.004 [95% confidence interval (CI) = 0.985, 1.023] and 0.993 (95% CI = 0.984, 1.002), respectively. The results were similar for 3- and 5-year exposures. For a 10-µg/m3 increase in 1-year PM10 and NO2 exposures, the adjusted HRs for chronic lower airway disease mortality were 1.068 (95% CI = 1.024, 1.113) and 1.029 (95% CI = 1.009, 1.050), respectively. In stratified analyses, exposures to PM10 and NO2 were associated with overall mortality in patients who were underweight and had a history of severe exacerbation.

Conclusion

In this large population-based study of patients with COPD, long-term PM10 and NO2 exposures were not associated with overall mortality but were associated with chronic lower airway disease mortality. PM10 and NO2 exposures were both associated with an increased risk of overall mortality, and with overall mortality in underweight individuals and those with a history of severe exacerbation.

Definitions of Chronic Obstructive Pulmonary Disease and COPD Exacerbation: A Modified Delphi Survey

Background

The Global Initiative for Obstructive Lung Disease (GOLD) update 2023 proposed new definitions of COPD and COPD exacerbation. However, an agreement on the definitions has not been made, either internationally or domestically. This study aimed to reach an agreement between experts on the new definitions of COPD and COPD exacerbation in South Korea.

Methods

A modified Delphi method was used to make an agreement on the definitions of COPD and COPD exacerbation proposed by the GOLD update 2023. We performed two rounds of the survey including 15 Korean experts on COPD, asthma, and tuberculosis.

Results

More than two-thirds of the experts agreed on 12 of the 13 statements related to the definitions of COPD and COPD exacerbation in the two rounds of the survey. The experts agreed on the definitions of COPD and COPD exacerbation that should be revised in line with the definitions proposed by the GOLD update 2023. However, the experts showed an uncertain opinion on the statement that the definition of COPD includes patients with persistent airflow obstruction due to bronchiectasis.

Conclusion

Based on this Delphi survey, experts' agreement was made on the definitions of COPD and COPD exacerbation proposed by the GOLD update 2023.

Association Between Air Pollution and Viral Infection in Severe Acute Exacerbation of Chronic Obstructive Pulmonary Disease

BACKGROUND

Respiratory pathogen infections and air pollution are main causes of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Air pollution has a direct effect on the airway epithelial barrier and the immune system, which can have an influence on infection. However, studies on the relationship between respiratory infections and air pollutants in severe AECOPD are limited. Thus, the objective of this study was to investigate the correlation between air pollution and respiratory pathogen in severe AECOPD.

METHODS

This multicenter observational study was conducted by reviewing electronic medical records of patients with AECOPD at 28 hospitals in South Korea. Patients were divided into four groups according to the comprehensive air-quality index (CAI) used in Korea. Identification rates of bacteria and viruses of each group were analyzed.

RESULTS

Viral pathogens were identified in 270 (36.7%) of 735 patients. Viral identification rate was different (P = 0.012) according to air pollution. Specifically, the virus detection rate was 55.9% in the group of CAI 'D' with the highest air pollution. It was 24.4% in the group of CAI 'A' with the lowest air pollution. This pattern was clearly seen for influenza virus A (P = 0.042). When further analysis was performed with particulate matter (PM), the higher/lower the PM level, the higher/lower the virus detection rate. However, no significant difference was found in the analysis related to bacteria.

CONCLUSION

Air pollution may make COPD patients more susceptible to respiratory viral infections, especially influenza virus A. Thus, on days with poor air quality, COPD patients need to be more careful about respiratory infections.

The impact of driving pressure on postoperative pulmonary complication in patients with different respiratory spirometry

Risk factors for postoperative pulmonary complication (PPC) have not been determined according to preoperative respiratory spirometry. Thus, we aimed to find contributors for PPC in patients with restrictive or normal spirometric pattern. We analyzed 654 patients (379 with normal and 275 with restrictive spirometric pattern). PPCs comprised respiratory failure, pleural effusion, atelectasis, respiratory infection, and bronchospasm. We analyzed the association between perioperative factors and PPC using binary logistic regression. In particular, we conducted subgroup analysis on the patients stratified according to preoperative spirometry. Of 654 patients, 27/379 patients (7.1%) with normal spirometric pattern and 33/275 patients (12.0%) with restrictive spirometric pattern developed PPCs. Multivariable analysis demonstrated that high driving pressure was the only intraoperative modifiable factor increasing PPC risk (OR = 1.13 [1.02-1.25], p = 0.025). In the subgroup of patients with restrictive spirometric pattern, intraoperative driving pressure was significantly associated with PPC (OR = 1.21 [1.05-1.39], p = 0.009), whereas driving pressure was not associated with PPC in patients with normal spirometric pattern (OR = 1.04 [0.89-1.21], p = 0.639). In patients with restrictive spirometric pattern, greater intraoperative driving pressure is significantly associated with increased PPC risk. In contrast, intraoperative driving pressure is not associated with PPC in patients with normal spirometric pattern.

Impacts of Asthma in Patients With Bronchiectasis: Findings From the KMBARC Registry

PURPOSE

Although the coexistence of asthma and bronchiectasis is common, the impacts of asthma on bronchiectastic patients (BE) have not been well evaluated because this issue using bronchiectasis cohorts has been investigated in only a few studies.

METHODS

In the present study, 598 patients who were prospectively enrolled in the Korean bronchiectasis registry were evaluated. The clinical characteristics between BE with asthma and those without asthma were compared.

RESULTS

Asthma was found in 22.4% of BE. BE with asthma had a higher body mass index (BMI) (P = 0.020), more dyspnea (P < 0.001), larger sputum volume (P = 0.015), and lower forced expiratory volume in 1 second (FEV1) (P < 0.001) than those without asthma. BE with asthma had a higher rate of previous pneumonia (P = 0.017) or measles (P = 0.037) than those without asthma. Regarding treatment, BE with asthma used inhaled corticosteroids, long-acting muscarinic antagonists, and leukotriene receptor antagonists more frequently than those without asthma. Although intergroup differences were not observed in disease severity of bronchiectasis (P = 0.230 for Bronchiectasis Severity Index and P = 0.089 for FACED), the Bronchiectasis Health Questionnaire (BHQ) scores indicating the quality of life, were significantly lower in BE with asthma than in those without asthma (61.6 vs. 64.8, P < 0.001). In a multivariable model adjusting for age, sex, body mass index, forced expiratory volume in 1 second %predicted, sputum volume, modified Medical Research Council dyspnea scale ≥ 2, and the number of involved lobes, asthma was associated with lower BHQ scores (β-coefficient = -2.579, P = 0.014).

CONCLUSIONS

BE with asthma have more respiratory symptoms, worse lung function, and poorer quality of life than those without asthma. A better understanding of the impacts of asthma in BE will guide appropriate management in this population.

Trends and factors associated with influenza vaccination in subjects with asthma: analysis of the Korea National Health and Nutrition Examination Survey between 2010 and 2019

BACKGROUND

Despite the importance of influenza vaccination, its rates in subjects with asthma are suboptimal, especially in the young population.

METHODS

Among 72,843 adults aged ⩾18 years from the Korea National Health and Nutrition Examination Survey conducted between 2010 and 2019, 1643 with asthma were included. The yearly trends and factors associated with influenza vaccination were analyzed in subjects with asthma. In addition, stratified analyses were performed by age group (<65 versus ⩾65 years).

RESULTS

During the study period, the overall influenza vaccination rate among subjects with asthma fluctuated from 51.0% to 64.3%, with a consistently higher vaccination rate in elderly subjects than in young subjects. Among young subjects with asthma, factors positively associated with influenza vaccination were female sex [adjusted odds ratio (aOR) = 1.66, 95% confidence interval (CI) = 1.11-2.49], current asthma being treated (aOR = 1.69, 95% CI = 1.14-2.50), history of pulmonary tuberculosis (aOR = 2.01, 95% CI = 1.04-3.87), and dyslipidemia (aOR = 1.86, 95% CI = 1.05-3.30). However, unmarried subjects showed an inverse relationship (aOR = 0.50, 95% CI = 0.34-0.75). In elderly subjects, unmarried status (aOR = 0.52, 95% CI = 0.29-0.94), being underweight (aOR = 0.29, 95% CI = 0.09-0.97), and having a low income (aOR = 0.42, 95% CI = 0.18-0.97) were factors negatively associated with influenza vaccination.

CONCLUSION

In the last 10 years, influenza vaccination rates have still been insufficient in subjects with asthma, particularly in young subjects. Considering the factors that are influencing the vaccination rates of young subjects, public policies to increase influenza vaccination rates in subjects with asthma need to be established urgently.

Longitudinal changes in pulmonary function and patient-reported outcomes after lung cancer surgery

Background

Surgery is the mainstay of treatment for non-small cell lung cancer, but the decline in pulmonary function after surgery is noticeable and requires attention. This study aimed to evaluate longitudinal changes in pulmonary function and integrated patient-reported outcomes (PROs) after lung cancer surgery.

Methods

Data were obtained from a prospective cohort study, the Coordinate Approach to Cancer Patients’ Health for Lung Cancer. Changes in forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁) at 2 weeks, 6 months, and 1 year after surgery, and the corresponding modified Medical Research Council (mMRC) dyspnea scale and chronic obstructive lung disease assessment test (CAT) scores were evaluated. Mixed effects model was used to investigate changes in pulmonary function and PROs.

Results

Among 620 patients, 477 (76.9%) underwent lobectomy, whereas 120 (19.4%) and 23 (3.7%) were treated with wedge resection/segmentectomy and bilobectomy/pneumonectomy, respectively. Both FVC and FEV₁ markedly decreased 2 weeks after surgery and improved thereafter; however, they did not recover to baseline values. The corresponding mMRC dyspnea scale and CAT scores worsened immediately after surgery. The dyspnea scale of the mMRC was still higher, while CAT scores returned to baseline one year after surgery, although breathlessness and lack of energy persisted. Compared to the changes from baseline of FVC and FEV₁ in patients who underwent lobectomy, patients who underwent bilobectomy/pneumonectomy showed a greater decrease in FVC and FEV₁, while wedge resection/segmentectomy patients had smaller decreases in FVC and FEV₁ at 2 weeks, 6 months, and 1 year after surgery. Bilobectomy/pneumonectomy patients had the highest mMRC dyspnea grade among the three groups, but the difference was not statistically significant one year after surgery.

Conclusions

After lung cancer surgery, pulmonary function and PROs noticeably decreased in the immediate post-operative period and improved thereafter, except for dyspnea and lack of energy. Proper information on the timeline of changes in lung function and symptoms following lung cancer surgery could guide patient care approaches after surgery.

Trial registration: ClinicalTrials.gov; No.: NCT03705546; URL: www.clinicaltrials.gov

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02149-9.

The Higher Incidence of COVID-19 in Patients With Non-Tuberculous Mycobacterial Pulmonary Disease: A Single Center Experience in Korea

The aim of our study was to investigate the incidence of and risk factors for coronavirus disease 2019 (COVID-19) in patients with non-tuberculous mycobacterial-pulmonary disease (NTM-PD). A total of 3,866 patients with NTM-PD were retrospectively identified from a single center. Compared to the general population of Korea, patients with NTM-PD had a substantially increased age-standardized incidence of COVID-19 from January 2020 to February 2021 (2.1% vs. 0.2%). The odds of being infected with COVID-19 was particularly higher in patients who received treatment for NTM-PD than in those who did not receive treatment for NTM-PD (adjusted odd ratio = 1.99, 95% confidence interval = 1.09-3.64, P = 0.026). Patients with NTM-PD might be regarded as a high-risk group for COVID-19 and may need a more proactive preventive strategy for COVID-19 and other pandemics in the future.

Lack of Association between Inhaled Corticosteroid Use and the Risk of Future Exacerbation in Patients with GOLD Group A Chronic Obstructive Pulmonary Disease

Background: As most clinical trials have been performed in more symptomatic and higher-risk patients, evidence regarding treatment in patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) group A chronic obstructive pulmonary disease (COPD) is limited. We assessed the distribution of inhaler treatment and sought to investigate the association between inhaled corticosteroid (ICS) use and future exacerbation in GOLD group A COPD patients. Methods: Patients with GOLD group A COPD who received maintenance inhalers were identified from a multicentre, prospective cohort in South Korea. Patients were categorized as group A when they had fewer symptoms and did not experience severe exacerbation in the previous year. Development of moderate or severe exacerbation during the 1-year follow-up was analysed according to baseline inhaler treatment. Results: In 286 patients with GOLD group A COPD, mono-bronchodilator (37.8%), dual-bronchodilator (29.0%), triple therapy (17.5%), and ICS/long-acting beta-2 agonist (15.4%) were used. Compared to patients without ICS-containing inhalers (N = 191), those using ICS (N = 95) were more dyspnoeic, and more likely to have asthma history, lower lung function, and bronchodilator response. During the 1-year follow-up, moderate or severe exacerbations occurred in 66 of 286 (23.1%) patients. In the multivariable logistic regression analysis, ICS-containing inhaler use was not associated with the development of exacerbation, even in the subgroup with a high probability of asthma–COPD overlap. Conclusion: Although about one-third of patients with GOLD group A COPD were using ICS-containing inhalers, use of ICS was not associated with a reduction in the future development of exacerbation.

Prospective Study of Proton Therapy for Lung Cancer Patients with Poor Lung Function or Pulmonary Fibrosis

PBT has a unique depth–dose curve with a Bragg peak that enables one to reduce the dose to normal lung tissue. We prospectively enrolled 54 patients with non-small cell lung cancer treated with definitive PBT. The inclusion criteria were forced expiratory volume in 1 s (FEV1) ≤ 1.0 L or FEV1 ≤ 50% of predicted or diffusing capacity of the lungs for carbon monoxide (DLco) ≤ 50%, or pulmonary fibrosis. The primary endpoint was grade ≥ 3 pulmonary toxicity, and secondary endpoints were changes in pulmonary function and quality of life. The median age was 71.5 years (range, 57–87). Fifteen (27.8%) and fourteen (25.9%) patients had IPF and combined pulmonary fibrosis and emphysema, respectively. The median predicted forced vital capacity (FVC), FEV1, and DLco were 77% (range, 42–104%), 66% (range, 31–117%), and 46% (range, 23–94%), respectively. During the follow-up (median, 14.7 months), seven (13.0%) patients experienced grade ≥ 3 pulmonary toxicity. Seven months after the completion of PBT, patients with IPF or non-IPF interstitial lung disease (ILD) experienced a decrease in the FVC but the decrease in DLco was not significant. Under careful monitoring by pulmonologists, PBT could be a useful treatment modality for lung cancer patients with poor lung function or pulmonary fibrosis.

Association of body mass index and COPD exacerbation among patients with chronic bronchitis

Background and objective

Chronic obstructive pulmonary disease (COPD) patients with a body mass index (BMI) < 25 kg/m² are prone to develop adverse event of pharmacological treatment for frequent exacerbation. As chronic bronchitis (CB) is one of the strong risk factors of exacerbation, we investigated the associations between BMI and COPD exacerbations in patients with CB.

Methods

Patients with COPD were included from the Korean COPD Subgroup Study (KOCOSS), a multicenter observational cohort study. CB was defined using the St. George’s Respiratory Questionnaire and the participants were categorized according to BMI cut-off of 25 kg/m². Exacerbations during a 1-year follow-up were compared among four groups: non-CB with BMI ≥ 25 kg/m², non-CB with BMI < 25 kg/m², CB with BMI ≥ 25 kg/m², and CB with BMI < 25 kg/m².

Results

Among the 1264 patients with COPD, 451 (35.7%) had CB and 353 (27.9%) had both CB and BMI < 25 kg/m². The COPD exacerbation risk increased across the non-CB with BMI < 25 kg/m², CB with BMI ≥ 25 kg/m², and CB with BMI < 25 kg/m² groups (adjusted incidence rate ratio [95% confidence interval] 1.21 [0.89–1.62], 1.20 [0.77–1.88], and 1.41 [1.02–1.91], respectively, compared to the non-CB with BMI ≥ 25 kg/m² group).

Conclusions

COPD patients having both CB and a BMI < 25 kg/m² are at higher risk of exacerbations. Considering that a BMI < 25 kg/m² often limits treatment options preventing exacerbations, modified guidelines might be needed for non-obese CB patients in Asia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01957-3.

Association Between Vitamin D Level and Respiratory Symptoms in Patients with Stable Chronic Obstructive Pulmonary Disease

Purpose

Vitamin D insufficiency or deficiency is prevalent in patients with chronic obstructive pulmonary disease (COPD). However, the association between vitamin D levels and respiratory symptoms in patients with stable COPD has not been fully investigated. This study evaluated the association between vitamin D levels and respiratory symptoms in patients with stable COPD.

Patients and Methods

Patients with COPD who had their serum 25-hydroxyvitamin D (25-OH vitamin D) level measured within 6 months of spirometry between January 2016 and April 2020 were retrospectively included. Respiratory symptoms were assessed using the modified Medical Research Council (mMRC) scale and COPD assessment test (CAT) score.

Results

Of the 329 included patients, 193, 88, and 48 were categorized as having vitamin D deficiency (<20 ng/mL), insufficiency (20–29 ng/mL), and sufficiency (≥30 ng/mL), respectively. The mean serum 25-OH vitamin D level of each group was 13.45 ng/mL, 24.61 ng/mL, and 38.90 ng/mL, respectively. Patients with vitamin D insufficiency/deficiency showed higher CAT scores than those with vitamin D sufficiency (p = 0.004). In multivariable adjusted models, vitamin D insufficiency/deficiency was significantly associated with a CAT score of 10 or more (adjusted odds ratio [aOR] = 2.41, 95% confidence interval [CI] = 1.20–4.82, p = 0.013) and mMRC ≥ 2 (aOR = 2.39, 95% CI = 1.08–5.32, p = 0.032). Among CAT items, the amount of phlegm (p = 0.008), chest tightness (p = 0.030), breathlessness walking upstairs (p < 0.001), home activity limitations (p = 0.002), and lack of energy (p = 0.003) were significantly associated with vitamin D insufficiency/deficiency after adjustment for age, sex, body mass index, smoking history, Charlson comorbidity index, post-bronchodilator forced expiratory volume in 1 second, and season of blood draw.

Conclusion

Vitamin D insufficiency/deficiency were associated with worse respiratory symptoms in patients with stable COPD.

Expeditious Resolution of Giant Bullae with Endobronchial Valves and Percutaneous Catheter Insertion

As bullae contribute to decreased lung function in chronic obstructive pulmonary disease (COPD) patients, effective decompression of large bullae is important. Bronchoscopic lung volume reduction via endobronchial one-way valves is less invasive and has a lower mortality rate than lung volume reduction surgery. We report the case of a 48-year-old male who presented with giant bullae that were expeditiously resolved with endobronchial valves and percutaneous catheter insertion. Three days later, imaging revealed marked decreases in the extent of bullae and atelectasis of the contralateral lung without any complications, including air leakage or pneumothorax. Combination of endobronchial valves and percutaneous catheter insertion might be helpful to accelerate the release of large bullae and to achieve improved lung function and higher levels of physical activity in patients with COPD.

Change in individual chronic obstructive pulmonary disease assessment test item scores after short-term bronchodilator therapy and its impact on exacerbation in treatment-naïve patients with chronic obstructive pulmonary disease

Background:

The chronic obstructive pulmonary disease (COPD) assessment test (CAT) measures the health status of patients with COPD. We aimed to investigate the change in individual CAT scores after short-term bronchodilator therapy among treatment-naïve patients with COPD.

Methods:

Data from 148 patients newly diagnosed with COPD between January 2016 and April 2020 were retrospectively analyzed. We compared the CAT score, modified Medical Research Council (mMRC) dyspnea grade, and forced expiratory volume in 1 s (FEV1) before and after short-term (6 ± 2 months) bronchodilator therapy. We analyzed the change trends using generalized estimating equations.

Results:

The mean patient age was 70.9 years, and 92.6% were male. The total CAT score did not significantly improve. However, among the CAT items, phlegm [adjusted difference: –0.22 (–0.48, –0.002)], chest tightness [–0.30 (–0.56, –0.05)], and breathlessness [–0.45 (–0.66, –0.23)] scores significantly improved after bronchodilator therapy. The patients were divided into two groups: CAT score improved ( n = 69) and not improved group ( n = 79). The development of moderate-to-severe exacerbations during follow-up was significantly lower (2.9% versus 17.7%, p = 0.004) in the CAT score improved group.

Conclusion:

The improvement in CAT items indicating respiratory symptoms was more evident than the CAT total score after short-term bronchodilator therapy. Despite the significant increase in FEV1 after bronchodilator therapy, fewer than half of the patients achieved meaningful improvement in CAT, and this group showed significantly lower development of exacerbation during follow-up.

A Multicenter Study to Identify the Respiratory Pathogens Associated with Exacerbation of Chronic Obstructive Pulmonary Disease in Korea

BACKGROUND

Although respiratory tract infection is one of the most important factors triggering acute exacerbation of chronic obstructive pulmonary disease (AE-COPD), limited data are available to suggest an epidemiologic pattern of microbiology in South Korea.

METHODS

A multicenter observational study was conducted between January 2015 and December 2018 across 28 hospitals in South Korea. Adult patients with moderate-to-severe acute exacerbations of COPD were eligible to participate in the present study. The participants underwent all conventional tests to identify etiology of microbial pathogenesis. The primary outcome was the percentage of different microbiological pathogens causing AE-COPD. A comparative microbiological analysis of the patients with overlapping asthma-COPD (ACO) and pure COPD was performed.

RESULTS

We included 1,186 patients with AE-COPD. Patients with pure COPD constituted 87.9% and those with ACO accounted for 12.1%. Nearly half of the patients used an inhaled corticosteroid-containing regimen and one-fifth used systemic corticosteroids. Respiratory pathogens were found in 55.3% of all such patients. Bacteria and viruses were detected in 33% and 33.2%, respectively. Bacterial and viral coinfections were found in 10.9%. The most frequently detected bacteria were Pseudomonas aeruginosa (9.8%), and the most frequently detected virus was influenza A (10.4%). Multiple bacterial infections were more likely to appear in ACO than in pure COPD (8.3% vs. 3.6%, p=0.016).

CONCLUSION

Distinct microbiological patterns were identified in patients with moderate-to-severe AE-COPD in South Korea. These findings may improve evidence-based management of patients with AE-COPD and represent the basis for further studies investigating infectious pathogens in patients with COPD.

Psychometric validation of the Korean Patient-Reported Outcome Measurement Information System (PROMIS)-29 Profile V2.1 among patients with chronic pulmonary diseases

Background

This study aimed to validate the Korean version of the Patient-Reported Outcome Measurement Information System 29 Profile V2.1 (K-PROMIS-29 V2.1) in a sample of patients with chronic pulmonary diseases (CPDs).

Methods

Participants were recruited from the respiratory disease outpatient clinics of Samsung Medical Center in Seoul, South Korea, from September to October 2018. Participants completed a survey questionnaire, including the K-PROMIS-29 V2.1 and Short Form Health Survey version-2.0 (SF-36v2). Modified Medical Research Council (mMRC) and chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) scores were obtained these scores from electronic medical records (EMRs). Exploratory and confirmatory factor analyses (CFA) and Pearson's correlations were used to evaluate the reliability and validity of the K-PROMIS-29 V2.1.

Results

The mean age [standard deviation (SD)] was 62.8 (12.0) years, and 19.2% had less than middle-school education. Disease types included bronchiectasis (n=46, 24.5%), COPD (n=45, 23.9%), nontuberculous mycobacterial lung disease (n=25, 13.3%), interstitial lung disease (n=22, 11.7%), and others (n=50, 26.6%). Cronbach's alpha coefficients of the 7 subdomains in the K-PROMIS-29 V2.1 ranged from 0.77 to 0.96, indicating satisfactory internal consistency. In CFA, the goodness-of-fit indices were high (comparative fit index =0.90, standardised root mean residual =0.06). Moderate correlations were observed between comparable subscales of the K-PROMIS-29 V2.1 and those of the SF-36v2 (r=0.55-0.70) and CAT (r=-0.80 to 0.70).

Conclusions

The findings of this study suggest that the K-PROMIS-29 V2.1 is a reliable and valid measure for assessing a broad range of health-related quality-of-life domains in patients with CPDs.

The long-term efficacy of domiciliary noninvasive positive pressure ventilation in COPD: A meta-analysis of randomized controlled trials

Background

We evaluated the long-term effects of domiciliary noninvasive positive-pressure ventilation (NIPPV) used to treat patients with chronic obstructive pulmonary disease (COPD).

Methods

Databases were searched to identify randomized controlled trials of COPD with NIPPV for longer than 1 year. Mortality rates were the primary outcome in this meta-analysis. The eight trials included in this study comprised data from 913 patients.

Results

The mortality rates for the NIPPV and control groups were 29% (118/414) and 36% (151/419), suggesting a statistically significant difference (risk ratio [RR], 0.79; 95% confidence interval [CI], 0.65–0.95). Mortality rates were reduced with NIPPV in four trials that included stable COPD patients. There was no difference in admission, acute exacerbation and quality of life between the NIPPV and control groups. There was no significant difference in withdrawal rates between the two groups (RR, 0.99; 95% CI, 0.72–1.36; p=0.94).

Conclusion

Maintaining long-term nocturnal NIPPV for more than 1 year, especially in patients with stable COPD, decreased the mortality rate, without increasing the withdrawal rate compared with long-term oxygen treatment.

Developing a diagnostic bundle for bronchiectasis in South Korea: A modified Delphi Consensus Study

Background

A diagnostic bundle for bronchiectasis in South Korea is necessary because the etiologies of bronchiectasis and related diseases vary significantly among different regions and ethnicities.

Methods

A modified Delphi method was used to develop expert consensus statements on a diagnostic bundle for bronchiectasis in South Korea. Initial statements proposed by a core panel, based on international bronchiectasis guidelines, were discussed over one online meeting and two email surveys by a panel of experts (≥70% agreement).

Results

Twenty-one experts participated in the study, and 30 statements on a diagnostic bundle for bronchiectasis were classified as recommended, conditional, or not recommended. The expert panel agreed that 1) a standardized diagnostic bundle is useful in clinical practice, 2) diagnostic tests for specific diseases, including immunodeficiency and allergic bronchopulmonary aspergillosis, are necessary when clinically suspected, 3) initial diagnostic tests, including sputum microbiology and spirometry, are essential in all bronchiectasis patients, and 4) patients should be referred to specialized centers when rare causes such as primary ciliary dyskinesia are suspected.

Conclusion

In this Delphi survey, expert consensus statements were generated on which specific diagnostic, laboratory, microbiologic, and pulmonary function tests to obtain when managing patients with bronchiectasis in South Korea.

Respiratory symptoms and health-related quality of life in post-tuberculosis subjects with physician-diagnosed bronchiectasis: a cross-sectional study

Background

Prevalence, respiratory symptoms, and quality of life (QoL) in post-tuberculosis (TB) subjects with bronchiectasis are not well elucidated.

Methods

Subjects who participated in the Korea National Health and Nutritional Examination Survey 2007–2009 were enrolled in this cross-sectional study. We evaluated the prevalence of physician-diagnosed bronchiectasis among post-TB subjects. We compared respiratory symptoms, physical activity limitations, and QoL between post-TB subjects with and without bronchiectasis.

Results

The prevalence of bronchiectasis was 3.3% among 963 post-TB subjects. Post-TB subjects with bronchiectasis showed a higher rate of asthma (29.6% vs. 4.9%, P<0.001) than those without bronchiectasis. Post-TB subjects with bronchiectasis showed more cough (23.9% vs. 6.7%, P=0.033) and physical activity limitations due to respiratory diseases (35.0% vs. 8.9%, P=0.033) than those without bronchiectasis. Furthermore, compared with post-TB subjects without bronchiectasis, those with bronchiectasis had lower QoL measured by the EuroQoL five-dimension (EQ-5D) index (0.84 vs. 0.93, P=0.048). Linear regression analysis found that the EQ-5D index in post-TB subjects with bronchiectasis was significantly lower than in those without bronchiectasis (difference estimate =–0.089, P=0.030), especially in the anxiety/depression component.

Conclusions

Post-TB subjects with bronchiectasis had more cough and physical activity limitations and lower health-related QoL than those without bronchiectasis.

Patient-Reported Outcomes Measurement Information System: Translation and Linguistic Validation of Six Profile Domains for Korean Adults

BACKGROUND

The purpose of the study was to translate and linguistically validate a Korean language version of the PROMIS (K-PROMIS) for the six profile adult domains: Fatigue, Pain Intensity, Pain Interference, Physical Function, Sleep Disturbance, and Ability to Participate in Social Roles and Activities.

METHODS

A total of 268 items were translated into Korean according to the Functional Assessment of Chronic Illness Therapy multilingual translation methodology. Participants first completed approximately 27 to 35 items and were then interviewed to evaluate the conceptual equivalence of the translation to the original English language source. The K-PROMIS items that met the a priori threshold of ≥ 20% of respondents with comprehension difficulties in the cognitive interview.

RESULTS

54 of the 268 items were identified as difficult items to comprehend for at least 20% of respondents in Round 1. The most frequently identified K-PROMIS domain on difficult items to comprehend was the Physical function (24.5%). Most items with linguistic difficulties were Fatigue and Physical function. Cultural difficulties were only included the Physical function and Ability to Participate in Social Roles and Activities domains. 25 of 54 items were slightly revised, and then these revised items were tested with additional six participants in Round 2, and most participants had no problems to understand modified items.

CONCLUSION

The six profile adult domains of K-PROMIS have been linguistically validated. Further psychometric validation of the K-PROMIS items will provide additional information of meaningful outcomes for chronic disease and clinical setting.

A therapeutic intervention for Alzheimer's disease using ginsenoside Rg3: its role in M2 microglial activation and non-amyloidogenesis

Previously, we have reported that ginsenoside Rg3 has typical activities for neuroprotection and Aβ42 clearance by modulating microglia. In this study, we determined the pivotal role of ginsenoside Rg3 in microglia and neuronal cells. In human microglia, Rg3 and its stereoisomers significantly restored inflammatory M1 to normal M0 state and promoted M2 activation by up-regulating acute cytokines such as interleukin-10 and Arginase 1. Moreover, scavenger receptor type A (SRA) was significantly elevated in the presence of ginsenoside Rg3 and 20(S)-Rg3. This indicated that ginsenoside Rg3 could play a crucial role in Aβ uptake and clearance under activated M2 state. We also observed that soluble amyloid precursor protein-alpha (sAPPα) and ADAM10 levels were increased in APP swe-transfected Nuro-2a neuronal cells, whereas sAPPβ was not processed, suggesting that ginsenoside Rg3 was involved in non-amyloidogenic processing. In immunocytochemistry, SRA and a disintegrin and metalloproteinase 10 (desintegrin and metalloproteinase-containing protein 10, ADAM10) were coincidently upregulated in the presence of ginsenoside Rg3 and its stereoisomers compared to those in normal control. Taken together, these results suggested that ginsenoside Rg3 could boost acute activation of microglia, promote Aβ uptake, and elevate the sAPPα processing under activated M2 state. Although in vivo studies need to be performed, it is certain that ginsenoside Rg3 is highly involved in ameliorating the pathogenesis of neurodegeneration and can be a promising candidate for treating Alzheimer's disease as a new therapeutic intervention.

P–370 RPL-protease A as a potential biomarker for predicting recurrent pregnancy loss

Study question

Could the reduction of RPL-protease A be involved in the dysfunctional trophoblast for resulting in recurrent pregnancy loss (RPL).

Summary answer

Low expression of RPL-protease A may result in RPL and low serum RPL-protease A level may be a potential biomarker for predicting RPL.

What is known already

The RPL-protease A is expressed and secreted by placenta. The RPL-protease A is involved in the pathogenesis of pre-eclampsia, and the serum RPL-protease A level is higher in the patients with pre-eclampsia than that of normal groups. In our previous study, we identified that the RPL-protease A mRNA level was lower in the villi of patients with RPL than that of normal groups.

Study design, size, duration

Using the CRISPR/Cas9 system, the RPL-protease A gene knockout BeWo cell (BeWo KO) line was established, and the wild type (BeWo WT) and BeWo KO cells were applied to investigate the roles of RPL-protease A in trophoblasts. The human serum RPL-protease A levels were investigated by Western blot analysis and ELISA kit.

Participants/materials, setting, methods

The cell-cell fusion, cell counting analysis, invasion and scratch wound assays, cell cycle analysis, and immunocytochemical analysis were used to investigate cellular functions of RPL-protease A in trophoblast. The sera were obtained from 32 normal pregnant women and 60 women with RPL. The Western blot analysis and ELISA were used for detection of serum RPL-protease A levels.

Main results and the role of chance

The β-hCG was detected in fused BeWo WT cells, while the BeWo KO cells cannot fuse and did not express the β-hCG. The ability of invasion was decreased, but the capacity of migration and proliferation was higher in BeWo KO cells than BeWo WT cells. Cell fusion related factor (β-hCG), and cell invasion related factors (MMP–2 and MMP–9) were highly expressed in BeWo WT cells, and cell related factor (FAK), and cell proliferation related factors (ERK, p38, JNK, MKK3, MKK6, Raf, and Ras) were highly expressed in BeWo KO cells. The Western blot analysis and ELISA indicate that the serum RPL-protease A level was decreased in patients with RPL compared to that of normal groups.

Limitations, reasons for caution

The results of this study have the limitation of RPL-protease A functions in vitro.

Wider implications of the findings: The cellular functions of RPL-protease A in trophoblasts were investigated to explain the pathogenesis of RPL, and low serum RPL-protease A level can be used for a potential biomarker predicting RPL.

Trial registration number

Not applicable

Association of Ventilatory Disorders with Respiratory Symptoms, Physical Activity, and Quality of Life in Subjects with Prior Tuberculosis: A National Database Study in Korea

Tuberculosis (TB) survivors experience post-TB lung damage and ventilatory function disorders. However, the proportions of obstructive and restrictive ventilatory disorders as well as normal ventilation among subjects with prior TB are unknown. In addition, the impacts of ventilatory disorder and its severity on respiratory symptoms, physical activity limitations, and the quality of life in subjects with prior TB remain unclear. Subjects who participated in the Korean National Health and Nutritional Examination Survey 2007–2016 were enrolled in this study. We evaluated the impact of each ventilatory disorder and its severity on respiratory symptoms, physical activity limitations, and quality of life (measured by the EuroQoL five dimensions questionnaire [EQ-5D] index values) in subjects with prior TB. Among 1466 subjects with prior TB, 29% and 16% had obstructive ventilatory disorders and restrictive ventilatory disorders, respectively. Mild and moderate obstructive ventilatory disorders were not associated with respiratory symptoms, physical activity limitations, or EQ-5D index value compared with normal ventilation; however, severe obstructive ventilatory disorders were associated with more respiratory symptoms (adjusted odds ratio [aOR] = 13.62, 95% confidence interval [CI] = 4.64–39.99), more physical activity limitation (aOR = 218.58, 95% CI = 26.82–1781.12), and decreased EQ-5D index (adjusted coefficient = −0.06, 95% CI = (−0.12–−0.10) compared with normal ventilation. Mild restrictive ventilatory disorders were associated with more respiratory symptoms (aOR = 2.10, 95% CI = 1.07–4.14) compared with normal ventilation, while moderate (aOR = 5.71, 95% CI = 1.14–28.62) and severe restrictive ventilatory disorders (aOR = 9.17, 95% CI = 1.02–82.22) were associated with physical activity limitation compared with normal ventilation. In conclusion, among subjects with prior TB, 29% and 16% developed obstructive and restrictive ventilatory disorders, respectively. Severe obstructive ventilatory disorder was associated with more respiratory symptoms, more physical activity limitation, and poorer quality of life, while severe restrictive ventilatory disorder was associated with more physical activity limitations.

Clinical Characteristics of COPD Patients According to COPD Assessment Test (CAT) Score Level: Cross-Sectional Study

PURPOSE

The chronic obstructive pulmonary disease (COPD) assessment test (CAT) is widely used to assess the impact of COPD symptoms on health status. Whilst the CAT consists of eight different items, details on the distribution of each item are limited. This study aimed to investigate the distribution and clinical implication of each CAT item, stratified by CAT severity group, in stable COPD patients.

PATIENTS AND METHODS

This was a cross-sectional study at a single referral hospital in South Korea. Spirometry confirmed COPD patients with CAT measured at the first clinical visit were retrospectively identified. Patients were categorized into three groups: low (0 ≤ CAT < 10), medium (10 ≤ CAT < 20), and high (20 ≤ CAT ≤ 40) impact group. For the purpose of this analysis, the first four items (cough, sputum, chest tightness, and dyspnea) and the remaining four items (activities, confidence, sleep and energy) were also grouped as "pulmonary" and "extra-pulmonary", respectively.

RESULTS

A total of 815 patients were included, and mean (SD) forced expiratory volume in 1 s (FEV1) was 62.8 (17.4) % pred. Among them, 300 patients (36.8%) were in the high impact group and had a greater exacerbation history and lower lung function. The proportion of "extra-pulmonary" items score was greater in patients with higher total CAT scores, with the activity and confidence items showing higher scores.

CONCLUSION

In our study, in addition to dyspnea, activity limitation is a particular problem in individual patients with higher CAT total scores, for which physicians need to pay more attention. Our study suggests that whilst CAT total score captures the overall impact of COPD, each item of the CAT contains potentially useful information in understanding the patient's symptom burden.

Prognostic Utility of Disproportionately Enlarged Subarachnoid Space Hydrocephalus in Idiopathic Normal Pressure Hydrocephalus Treated with Ventriculoperitoneal Shunt Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Disproportionately enlarged subarachnoid space hydrocephalus is a specific radiologic marker for idiopathic normal pressure hydrocephalus. However, controversy exists regarding the prognostic utility of disproportionately enlarged subarachnoid space hydrocephalus.

PURPOSE

Our aim was to evaluate the prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus and its predictive utility regarding prognosis in patients treated with ventriculoperitoneal shunt surgery.

DATA SOURCES

We used MEDLINE and EMBASE databases.

STUDY SELECTION

We searched for studies that reported the prevalence or the diagnostic performance of disproportionately enlarged subarachnoid space hydrocephalus in predicting treatment response.

DATA ANALYSIS

The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus was obtained. Pooled sensitivity, specificity, and area under the curve of disproportionately enlarged subarachnoid space hydrocephalus to predict treatment response were obtained. Subgroup and sensitivity analyses were performed to explain heterogeneity among the studies.

DATA SYNTHESIS

Ten articles with 812 patients were included. The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus was 44% (95% CI, 34%-54%). The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus was higher in the studies using the second edition of the Japanese Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus compared with the studies using the international guidelines without statistical significance (52% versus 43%, P = .38). The pooled sensitivity and specificity of disproportionately enlarged subarachnoid space hydrocephalus for prediction of treatment response were 59% (95% CI, 38%-77%) and 66% (95% CI, 57%-74%), respectively, with an area under the curve of 0.67 (95% CI, 0.63-0.71).

LIMITATIONS

The lack of an established method for assessing disproportionately enlarged subarachnoid space hydrocephalus using brain MR imaging served as an important cause of the heterogeneity.

CONCLUSIONS

Our meta-analysis demonstrated a relatively low prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus and a poor diagnostic performance for treatment response.

Increased Incidence and Associated Risk Factors of Aspergillosis in Patients with Bronchiectasis

There are insufficient data regarding the relationship between non-cystic fibrosis bronchiectasis and incident aspergillosis. We performed a population-based, matched cohort study using data from the Korean National Health Insurance database between 2003 and 2013. The incidence of aspergillosis was 50/100,000 person-years in the bronchiectasis cohort and 11/100,000 person-years in the matched cohort (subdistribution hazard ratio, 4.53; 95% confidence interval (CI), 3.25–6.32). Among the bronchiectasis cohort, chronic obstructive pulmonary disease (adjusted HR, 1.95; 95% CI, 1.07–3.57), previous pulmonary tuberculosis (adjusted HR, 3.67; 95% CI, 2.03–6.64), and non-tuberculous mycobacterial pulmonary disease (adjusted HR, 11.25; 95% CI, 1.49–85.18) increased the risk of incident aspergillosis. The incidence of aspergillosis in patients with bronchiectasis was approximately 4.5-fold that in those without bronchiectasis. Comorbid pulmonary diseases—chronic obstructive pulmonary disease, previous pulmonary tuberculosis, and non-tuberculous mycobacterial pulmonary disease—significantly increased the risk of aspergillosis in patients with bronchiectasis. Our study indicates that close monitoring is warranted for aspergillosis in patients with bronchiectasis.

Effect of perioperative bronchodilator therapy on postoperative pulmonary function among lung cancer patients with COPD

Chronic obstructive pulmonary disease (COPD), an established risk factor for lung cancer, remains largely undiagnosed and untreated before lung cancer surgery. We evaluated the effect of perioperative bronchodilator therapy on lung function changes in COPD patients who underwent surgery for non-small cell lung cancer (NSCLC). From a database including NSCLC patients undergoing lung resection, COPD patients were identified and divided into two groups based on the use of bronchodilator during the pre- and post-operative period. Changes in forced expiratory volume in 1 s (FEV1) and postoperative complications were compared between patients treated with and without bronchodilators. Among 268 COPD patients, 112 (41.8%) received perioperative bronchodilator, and 75% (84/112) were newly diagnosed with COPD before surgery. Declines in FEV1 after surgery were alleviated by perioperative bronchodilator even after adjustments for related confounding factors including surgical extent, surgical approach and preoperative FEV1 (adjusted mean difference in FEV1 decline [95% CI] between perioperative bronchodilator group and no perioperative bronchodilator group; - 161.1 mL [- 240.2, - 82.0], - 179.2 mL [- 252.1, - 106.3], - 128.8 mL [- 193.2, - 64.4] at 1, 4, and 12 months after surgery, respectively). Prevalence of postoperative complications was similar between two groups. Perioperative bronchodilator therapy was effective to preserve lung function, after surgery for NSCLC in COPD patients. An active diagnosis and treatment of COPD are required for surgical candidates of NSCLC.

Stages of menopause and abnormal lung function: a cross-sectional study of middle-aged women

OBJECTIVE

Whether hormonal changes during menopausal transition postmenopause stages influence pulmonary function is not clearly understood. We evaluated the association between each stage of menopause and the prevalence of abnormal lung function in healthy middle-aged women. We hypothesized that the prevalence of abnormal lung function would increase from the late menopausal transition stage during menopausal transition postmenopause stages.

METHODS

The study population included women 40 to 65 years of age who underwent comprehensive health screening examination at the Kangbuk Samsung Hospital Total Healthcare Centers from January 2015 to December 2017. Stages of menopause (premenopausal, early menopausal transition, late menopausal transition, and postmenopausal) were defined using the 2011 Stages of Reproductive Aging Workshop (STRAW + 10) criteria. Abnormal lung function was defined based on spirometry as forced expiratory volume in 1 second/forced vital capacity less than70% or forced vital capacity less than 80% predicted. Prevalence ratios (PRs) for abnormal lung function by stages of menopause were estimated from logistic regression models adjusted for age, anthropometric measurements, lifestyle factors, medical history, lipid and inflammatory biomarkers, and reproductive factors.

RESULTS

Among 43,822 participants, there were 4,615 participants (10.5%) with restrictive ventilatory disorder and 653 participants (1.5%) with obstructive ventilatory disorder. The fully adjusted PRs (95% confidence interval) for abnormal ventilatory disorder comparing early menopausal transition, late menopausal transition, and postmenopausal stage to premenopausal stage were 1.01 (0.94-1.08), 1.13 (1.03-1.22), and 1.10 (0.98-1.22), respectively. The fully adjusted PRs for restrictive ventilatory disorder comparing early menopausal transition, late menopausal transition, and postmenopausal stages to premenopausal stage were 1.02 (0.94-1.11), 1.18 (1.06-1.30), and 1.15 (1.00-1.31), respectively. There was, however, no clear association between stages of menopause and obstructive ventilatory disorder.

CONCLUSIONS

In this large study of middle-aged women, the fully adjusted prevalence of abnormal lung function, particularly that of restrictive ventilatory disorder, was higher in women in late menopausal transition and menopausal stages compared to women in premenopausal stage.

Favorable Response to Long-Term Azithromycin Therapy in Bronchiectasis Patients with Chronic Airflow Obstruction Compared to Chronic Obstructive Pulmonary Disease Patients without Bronchiectasis

Purpose

Long-term macrolide treatment is recommended for patients with chronic obstructive pulmonary disease (COPD) with frequent exacerbations. Bronchiectasis is a common comorbid condition in patients with COPD, for which long-term azithromycin is effective in preventing exacerbation. This study aimed to compare the effect of long-term azithromycin between bronchiectasis patients with chronic airflow obstruction (CAO) and COPD patients without bronchiectasis.

Patients and Methods

Patients with CAO who received azithromycin for more than 12 weeks were retrospectively identified at a single referral hospital. CAO was defined as a post-bronchodilator forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) <0.7, and bronchiectasis was determined using computed tomography. The development of exacerbation and symptom improvement were compared between bronchiectasis patients with CAO and COPD patients without bronchiectasis.

Results

A total of 59 patients (43 in bronchiectasis with CAO group vs 16 in COPD without bronchiectasis group) were included in this study. Compared to COPD patients without bronchiectasis, those in bronchiectasis with CAO group were younger, more likely to be female, and never smokers. There was no difference in the previous exacerbation history or FEV₁ between the two groups. The median duration of azithromycin treatment was 15 months (interquartile range, 8–25 months). At the 12-month follow-up, the development of ≥2 moderate or ≥1 severe exacerbations was significantly lower in bronchiectasis with CAO group than in COPD without bronchiectasis group (46.5% vs 87.5%, P = 0.005). The proportion of patients with symptom improvement determined by the COPD assessment test score was also significantly higher in bronchiectasis with CAO group than COPD without bronchiectasis group at the 12-month follow-up (68.2% vs 16.7%, P = 0.004).

Conclusion

Bronchiectasis patients with CAO could benefit more from long-term azithromycin treatment than COPD patients without bronchiectasis.