Endobronchial valves for emphysema and persistent air-leak: 10-year experience in an Asian country.

BACKGROUND: Endobronchial valve (EBV) therapy, a validated method for bronchoscopic lung volume reduction (BLVR) in severe emphysema, has been explored for persistent air-leak (PAL) management. However, its effectiveness and safety in the Asian population require further real-world evaluation. In this study, we assessed the outcomes of treatment with EBV within this demographic. METHODS: We conducted a retrospective analysis of medical records from 11 Korean centers. For the emphysema cohort, inclusion criteria were patients diagnosed with emphysema who underwent bronchoscopy intended for BLVR. We assessed these patients for clinical outcomes of chronic obstructive pulmonary disease. All patients with PAL who underwent treatment with EBV were included. We identified the underlying causes of PAL and evaluated clinical outcomes after the procedure. RESULTS: The severe emphysema cohort comprised 192 patients with an average age of 70.3 years, and 95.8% of them were men. Ultimately, 137 underwent treatment with EBV. Three months after the procedure, the BLVR group demonstrated a significant improvement in forced expiratory volume in 1 s (+160 mL vs. +30 mL; P = 0.009). Radiographic evidence of lung volume reduction 6 months after BLVR was significantly associated with improved survival (adjusted hazard ratio 0.020; 95% confidence interval 0.038-0.650; P = 0.010). Although pneumothorax was more common in the BLVR group (18.9% vs. 3.8%; P = 0.018), death was higher in the no-BLVR group (38.5% vs. 54.5%, P = 0.001), whereas other adverse events were comparable between the groups. Within the subset of 18 patients with PAL, the predominant causes of air-leak included spontaneous secondary pneumothorax (44.0%), parapneumonic effusion/empyema (22.2%), and post-lung resection surgery (16.7%). Following the treatment, the majority (77.8%) successfully had their chest tubes removed. Post-procedural complications were minimal, with two incidences of hemoptysis and one of empyema, all of which were effectively managed. CONCLUSIONS: Treatment with EBV provides substantial clinical benefits in the management of emphysema and PAL in the Asian population, suggesting a favorable outcome for this therapeutic approach.

Application of Microbiome-Based Therapies in Chronic Respiratory Diseases.

The application of microbiome-based therapies in various areas of human disease has recently increased. In chronic respiratory disease, microbiome-based clinical applications are considered compelling options due to the limitations of current treatments. The lung microbiome is ecologically dynamic and affected by various conditions, and dysbiosis is associated with disease severity, exacerbation, and phenotype as well as with chronic respiratory disease endotype. However, it is not easy to directly modulate the lung microbiome. Additionally, studies have shown that chronic respiratory diseases can be improved by modulating gut microbiome and administrating metabolites. Although the composition, diversity, and abundance of the microbiome between the gut and lung are considerably different, modulation of the gut microbiome could improve lung dysbiosis. The gut microbiome influences that of the lung via bacterial-derived components and metabolic degradation products, including short-chain fatty acids. This phenomenon might be associated with the cross-talk between the gut microbiome and lung, called gut-lung axis. There are multiple alternatives to modulate the gut microbiome, such as prebiotics, probiotics, and postbiotics ingestion and fecal material transplantation. Several studies have shown that high-fiber diets, for example, present beneficial effects through the production of short-chain fatty acids. Additionally, genetically modified probiotics to secrete some beneficial molecules might also be utilized to treat chronic respiratory diseases. Further studies on microbial modulation to regulate immunity and potentiate conventional pharmacotherapy will improve microbiome modulation techniques, which will develop as a new therapeutic area in chronic respiratory diseases.

Fine particulate matter aggravates smoking induced lung injury via NLRP3/caspase-1 pathway in COPD.

BACKGROUND: Exposure to noxious particles, including cigarette smoke and fine particulate matter (PM2.5), is a risk factor for chronic obstructive pulmonary disease (COPD) and promotes inflammation and cell death in the lungs. We investigated the combined effects of cigarette smoking and PM2.5 exposure in patients with COPD, mice, and human bronchial epithelial cells. METHODS: The relationship between PM2.5 exposure and clinical parameters was investigated in patients with COPD based on smoking status. Alveolar destruction, inflammatory cell infiltration, and pro-inflammatory cytokines were monitored in the smoking-exposed emphysema mouse model. To investigate the mechanisms, cell viability and death and pyroptosis-related changes in BEAS-2B cells were assessed following the exposure to cigarette smoke extract (CSE) and PM2.5. RESULTS: High levels of ambient PM2.5 were more strongly associated with high Saint George's respiratory questionnaire specific for COPD (SGRQ-C) scores in currently smoking patients with COPD. Combined exposure to cigarette smoke and PM2.5 increased mean linear intercept and TUNEL-positive cells in lung tissue, which was associated with increased inflammatory cell infiltration and inflammatory cytokine release in mice. Exposure to a combination of CSE and PM2.5 reduced cell viability and upregulated NLRP3, caspase-1, IL-1ß, and IL-18 transcription in BEAS-2B cells. NLRP3 silencing with siRNA reduced pyroptosis and restored cell viability. CONCLUSIONS: PM2.5 aggravates smoking-induced airway inflammation and cell death via pyroptosis. Clinically, PM2.5 deteriorates quality of life and may worsen prognosis in currently smoking patients with COPD.

Does Rheumatoid Arthritis Increase the Risk of COPD?: A Nationwide Retrospective Cohort Study.

BACKGROUND: Most reports of pulmonary manifestations in rheumatoid arthritis (RA) have been related to interstitial lung diseases. RA and COPD are both chronic inflammatory systemic diseases. RESEARCH QUESTION: Does RA increase the risk of developing COPD? Is there a difference between seropositive and seronegative RA in the risk of COPD? STUDY DESIGN AND METHODS: Using the Korean National Health Insurance Database, we screened individuals diagnosed with RA between 2010 and 2017. We identified 46,030 patients with RA (32,608 with seropositive RA and 13,422 with seronegative RA) and 230,150 matched control individuals; we monitored them until December 2019. We used multivariate Cox proportional hazard models to estimate the adjusted hazard ratio (aHR) of risk factors for the development of COPD. RESULTS: The incidence of COPD among patients with RA was 5.04 per 1,000 person-years; it was 2.23 per 1,000 person-years in the control group. Patients with RA showed a higher risk of developing COPD (aHR, 2.11; 95% CI, 1.96-2.28) compared with the control group. Although both seropositive RA and seronegative RA were associated with an increased risk of COPD, patients with seropositive RA had a higher risk for the development of COPD (aHR, 1.26; 95% CI, 1.09-1.46) than patients with seronegative RA. In the subgroup analyses, smoking history did not demonstrate significant interactions between RA and COPD development. INTERPRETATION: RA was shown to be associated with an increased risk of COPD development, augmented by seropositivity. Physicians should monitor respiratory symptoms and pulmonary function carefully in patients with RA.

Smartphone application-based rehabilitation in patients with chronic respiratory and cardiovascular diseases.

Rehabilitation improves symptoms, quality of life, and survival in patients with chronic respiratory or cardiovascular disease. We evaluated smartphone application-based rehabilitation programs for patients with chronic respiratory or cardiovascular diseases. This was a single-center prospective single arm study. Participants underwent smartphone application-based pulmonary or cardiac rehabilitation for 12 weeks. A total of 93 participants were recruited, and 75 visited after rehabilitation. Their median age was 67.0 (interquartile range, 60.0-70.8) years, and 60 (80.0%) were men. For patients with chronic respiratory disease (n = 41), VO2peak (median 13.7 to 15.4 ml/kg/min, P = 0.049), chronic obstructive pulmonary disease assessment test (median 14 to 6, P < 0.001), Euro-QoL 5-Dimension 5-Level (EQ-5D-5L) index (median 0.795 to 0.862, P = 0.001), and Health-related Quality of Life Instrument with 8 Items (HINT-8) index (median 0.784 to 0.855, P < 0.001) were significantly improved. For patients with chronic cardiovascular disease (n = 34), VO2peak (median 21.8 to 23.3, P = 0.007), EQ-5D-5L index (median 0.871 to 1.000, P = 0.037), and HINT-8 index (median 0.890 to 0.903, P < 0.001) were significantly improved. The smartphone application-based rehabilitation program improved exercise capacity and quality of life in patients with chronic respiratory or cardiovascular disease.Trial registration: https://clinicaltrials.gov/ct2/show/NCT05383950 (20/05/2022).

Automated sepsis detection with vancomycin- and allantoin-polydopamine magnetic nanoparticles.

Rapid and accurate identification of the bacteria responsible for sepsis is paramount for effective patient care. Molecular diagnostic methods, such as polymerase chain reaction (PCR), encounter challenges in sepsis due to inhibitory compounds in the blood, necessitating their removal for precise analysis. In this study we present an innovative approach that utilizes vancomycin (Van) and allantoin (Al)-conjugated polydopamine (PDA)-coated magnetic nanoparticles (MNPs) for the rapid and automated enrichment of bacteria and their DNA extraction from blood without inducing clumping and aggregation of blood. Al/Van-PDA-MNPs, facilitated by IMS, eliminate the need for preliminary sample treatments, providing a swift and efficient method for bacterial concentration and DNA extraction within an hour. Employing Al/Van-PDA-MNPs within an automated framework has markedly improved our ability to pre-concentrate various Gram-negative and Gram-positive bacteria directly from blood samples. This advancement has effectively reduced the detection threshold to 102 colony-forming unit/mL by both PCR and quantitative PCR. The method's expedited processing time, combined with its precision, positions it as a feasible diagnostic tool for diverse healthcare settings, ranging from small clinics to large hospitals. Furthermore, the innovative application of nanoparticles for DNA extraction holds promising potential for advancing sepsis diagnostics, enabling earlier interventions and improving patient outcomes.

Isolated respiratory tract microorganisms and clinical characteristics in asthma exacerbation of obese patients: a multicenter study.

BACKGROUND: Viral infection is a risk factor for asthma exacerbation (AE). However, bacterial infections related to AE in adults are poorly known. On the other hand, obese patients with asthma have their own clinical and biological characteristics compared with non-obese patients. METHODS: We investigated the differences in isolated pathogens for AE between obese and non-obese patients with asthma. We included 407 patients with AE from 24 medical centers in Korea. Microorganisms isolated from culture, RT-PCR or serologic tests using lower respiratory tract specimens were retrospectively investigated. RESULTS: A total of 171 obese and 236 non-obese patients with asthma were included for analysis. Compared to non-obese patients, obese patients were associated with women (77.2% vs. 63.6%), never smoker (82.5% vs. 73.9%), shorter duration of asthma (7.9 ± 8.4 vs. 10.5 ± 10.1 years), less history of pulmonary tuberculosis (8.8% vs. 17.4%), and more comorbidity of allergic rhinitis (48.5% vs. 0.8%). Viral and/or bacterial infections were detected in 205 patients (50.4%) with AE. The numbers of patients with viral only, bacterial only, or both infections were 119, 49, and 37, respectively. The most commonly isolated bacterium was Streptococcus pneumoniae, followed by Pseudomonas aeruginosa and Chlamydia pneumoniae. Obese patients showed a lower incidence of Chlamydia pneumoniae infection. In the non-obese group, bacterial infection, especially Chlamydia pneumoniae infection, was significantly associated with the duration of systemic corticosteroid use (13.6 ± 19.8 vs. 9.7 ± 6.7 days, p = 0.049). CONCLUSION: Bacterial infection was associated with a longer period of corticosteroid use in the non-obese group. Acute Chlamydia pneumoniae infection was less associated with obese patients with AE. Further well-designed studies are needed to evaluate microorganisms and the efficacy of antibiotics in patients with AE.

Positive airway pressure therapy compliance in patients with comorbid insomnia and sleep apnea (COMISA).

Objectives: This study aimed to compare positive airway pressure (PAP) therapy compliance between patients with comorbid insomnia and sleep apnea (COMISA) and those with obstructive sleep apnea (OSA) alone, while assessing the influence of insomnia clinic visits on PAP compliance. Methods: Patients diagnosed with OSA and initiated on PAP therapy between January 2012 and December 2021 were included. The COMISA group (n = 43) comprised patients with insomnia, while the control group (n = 86) consisted of OSA patients without insomnia, matched 1:2 based on age and sex. COMISA patients were further categorized into Group A (n = 20) with at least two insomnia clinic visits and Group B (n = 23) with minimal or no visits. PAP compliance was evaluated for each group at 3 and 9 months. Results: No significant differences were observed in PAP compliance between COMISA patients and OSA patients without insomnia. Within the COMISA group, the impact of insomnia clinic visits on PAP compliance was not significant. No significant difference was observed in the daily PAP usage between the two groups at 3 months (265.5 ± 145.9 min in Group A vs. 236.3 ± 152.3 min in Group B, p = 0.760) or 9 months (213.4 ± 155.3 min in Group A vs. 166.3 ± 158.3 min in Group B, p = 0.538). Percentages of PAP users and nights with PAP use exceeding 4 hours also showed no significant differences at both intervals. Conclusion: This study demonstrated no significant disparity in PAP compliance between the COMISA and control groups at either 3 or 9 months. Furthermore, insomnia clinic visits did not significantly impact PAP compliance in COMISA patients during the 3- and 9-month intervals.

Clinical Efficacy of Mobile App-Based, Self-Directed Pulmonary Rehabilitation for Patients With Chronic Obstructive Pulmonary Disease: Systematic Review and Meta-Analysis.

Background: Pulmonary rehabilitation is well known to improve clinical symptoms (including dyspnea), quality of life, and exercise capacity in patients with chronic obstructive pulmonary disease (COPD). However, researchers have reported difficulties in practicing center-based pulmonary rehabilitation. Recently, mobile app-based pulmonary rehabilitation has become available in clinical practice. We investigated the clinical outcomes of mobile app-based pulmonary rehabilitation in patients with COPD. Objective: The objective of our study was to evaluate the clinical efficacy of mobile app-based pulmonary rehabilitation versus conventional center-based pulmonary rehabilitation for patients with COPD, using a systematic review and meta-analysis. Methods: A systematic search of the literature published between January 2007 and June 2023 was performed, using the PubMed, Embase, Cochrane, and CINAHL databases to identify relevant randomized controlled trials involving patients with COPD. Pulmonary rehabilitation programs needed to provide an exercise program on a smartphone app. Study outcomes, including exercise capacity, symptom scores, quality of life, and hospitalization, were evaluated. The meta-analysis evaluated mean differences in 6-minute walk test distances (6MWDs), COPD Assessment Test (CAT) scores, modified Medical Research Council (mMRC) dyspnea scale scores, St. George Respiratory Questionnaire (SGRQ) scores, and risk ratios for hospitalization resulting from disease exacerbation. Results: Of the 1173 screened studies, 10 were included in the systematic review and 9 were included in the meta-analysis. Further, 6 studies were multicenter studies. There were a total of 1050 participants, and most were aged ≥65 years. There were discrepancies in the baseline participant characteristics, smartphone apps, interventions, and study outcomes among the included studies. In the meta-analysis, 5 studies assessed 6MWDs (mean difference 9.52, 95% CI -3.05 to 22.08 m), 6 studies assessed CAT scores (mean difference -1.29, 95% CI -2.39 to -0.20), 3 studies assessed mMRC dyspnea scale scores (mean difference -0.08, 95% CI -0.29 to 0.13), 2 studies assessed SGRQ scores (mean difference -3.62, 95% CI -9.62 to 2.38), and 3 studies assessed hospitalization resulting from disease exacerbation (risk ratio 0.65, 95% CI 0.27-1.53). These clinical parameters generally favored mobile app-based pulmonary rehabilitation; however, a statistically significant difference was noted only for the CAT scores (P=.02). Conclusions: Despite some discrepancies in the baseline participant characteristics and interventions among studies, mobile app-based pulmonary rehabilitation resulted in favorable exercise capacity, symptom score, quality of life, and hospitalization outcomes when compared with conventional pulmonary rehabilitation. In the meta-analysis, the CAT scores of the mobile app-based pulmonary rehabilitation group were significantly lower than those of the control group (P=.02). In real-world practice, mobile app-based pulmonary rehabilitation can be a useful treatment option when conventional center-based pulmonary rehabilitation is not feasible.

COPD Risk Factor Profiles in General Population and Referred Patients: Potential Etiotypes.

Purpose: To identify the risk factors for chronic obstructive pulmonary disease (COPD) in view of potential etiotypes in a general population and referred COPD patients. Patients and Methods: We performed a cross-sectional observational study utilizing two distinct datasets: a dataset of a general population including 2430 subjects with COPD from the Korea National Health and Nutrition Examination Survey (KNHANES) and another dataset of referral clinics including 579 patients with COPD from the Korean Obstructive Lung Disease (KOLD). Results: The mean age of both groups was 67 years, and 71.2% and 93.8% were male in the COPD subjects from the KNHANES and the KOLD, respectively. The mean forced expiratory volume in 1 second of predicted value was 79.1% (KNHANES) and 55.4% (KOLD). The frequency of risk factors of cigarette smoking (C), infection (I), pollution (P), and asthma (A) was 54.6%, 9.4%, 10.7%, and 7.9%, respectively, in the KNHANES COPD subjects, and 88.4%, 26.6%, 41.6%, and 35.2%, respectively, in the KOLD COPD subjects. Risk factors were unidentified in 32.6% (KNHANES) and 3.1% (KOLD) of COPD subjects. Additionally, 14.1% and 66.2% of subjects with COPD had two or more risk factors in the KNHANES and KOLD, respectively. Conclusion: The profiles of risk factors C, I, P, and A were identified and appeared to be different among the two COPD groups from a general population or referral clinics. In some of the COPD subjects, risk factors were not identified, so we should endeavour to find out unidentified COPD risk factors, especially in the general population.

Randomised controlled trial of a behavioural intervention to reduce exposure to PM2.5 in patients with COPD.

BACKGROUND: Fine particulate matter (PM2.5) is a well-known risk factor for worse outcomes of chronic obstructive pulmonary disease (COPD). However, evidence-based guidance on effective personal behavioural strategies to minimise the effects of PM2.5 is limited. This study aimed to assess the effectiveness of a behavioural intervention in reducing PM2.5 exposure and improving clinical outcomes in patients with COPD. MATERIALS AND METHODS: Participants were 1:1 randomised, and the intervention group received a behavioural intervention consisting of five activities, while the control group received usual care. The participants were followed up for 9 months. The primary outcomes were differences in the score of St. George's Respiratory Questionnaire for patients with COPD (SGRQ-C) and COPD assessment test (CAT) from baseline. RESULTS: A total of 106 participants were enrolled and 102 completed the study. At the end of the study, the intervention group showed significant improvements in the primary outcomes compared to the control group, with a group difference of -5.9 in the reduction of total SGRQ-C (-3.4 vs. 2.5; p = 0.049) and -3.8 in the CAT score (-1.2 vs. 2.7; p = 0.001). Participants with good adherence to the intervention demonstrated a greater extent of improvement in CAT score and lower PM2.5 levels compared to those who had poor adherence or were in the control group. Regular checking of air quality forecasts was significantly associated with a reduction in CAT scores among all the intervention activities. CONCLUSION: Individual-level behavioural interventions can be an effective strategy for mitigating the health hazards associated with PM2.5. CLINICALTRIALS: gov Identifier: NCT04878367.

Systemic antibiotics cause deterioration of emphysema associated with exaggerated inflammation and autophagy.

The interaction between the microbial environment and the host is important for immune homeostasis. Recent research suggests that microbiota dysbiosis can be involved in respiratory diseases. Emphysema is a chronic inflammatory disease, but it is unclear whether dysbiosis caused by antibiotics can affect disease progression. Here, we tried to elucidate the effect of systemic antibiotics on smoking-exposed emphysema models. In this study, the antibiotic mixture caused more alveolar destruction and airspace expansion in the smoking group than in the smoking only or control groups. This emphysema aggravation as a result of antibiotic exposure was associated with increased levels of inflammatory cells, IL-6, IFNγ and protein concentrations in bronchoalveolar lavage fluid. Proteomics analysis indicated that autophagy could be involved in antibiotic-associated emphysema aggravation, and increased protein levels of LC3B, atg3, and atg7 were identified by Western blotting. In microbiome and metabolome analyses, the composition of the gut microbiota was different with smoking and antibiotic exposure, and the levels of short-chain fatty acids (SCFAs), including acetate and propionate, were reduced by antibiotic exposure. SCFA administration restored emphysema development with reduced inflammatory cells, IL-6, and IFNγ and decreased LC3B, atg3, and atg7 levels. In conclusion, antibiotics can aggravate emphysema, and inflammation and autophagy may be associated with this aggravation. This study provides important insight into the systemic impact of microbial dysbiosis and the therapeutic potential of utilizing the gut microbiota in emphysema.

Superoxide dismutase secreting Bacillus amyloliquefaciens spores attenuate pulmonary fibrosis.

Superoxide dismutase (SOD) can convert active oxygen to oxygen or hydrogen peroxide, and recent research has suggested that it can protect against lung damage and fibrosis. Clinical applications based on SOD remain limited however due to costs and low stability. We here investigated a potential new therapeutic delivery system for this enzyme in the form of SOD-overexpressing Bacillus amyloliquefaciens spores which we introduced into a bleomycin-induced pulmonary fibrosis mouse model. This treatment significantly alleviated the disease, as quantified using a hydroxyproline assay, at 107 colony forming unit (CFU) of Bacillus spores per day. Exposure of the mice to the spores was further found to decrease the lung mRNA levels of CTGF, Col1a1, α-SMA, TGF-ß, TNF-α, and IL-6, and the protein levels of TGF-ß, Smad2/3, αSMA and Col1a1, all major indicators of pulmonary fibrosis. Survival benefits, and reduced byproducts of lipid peroxidase such as malondialdehyde and 4-hydroxynen, were also noted in the treated animals. The beneficial effects of these Bacillus spores on pulmonary fibrosis were further found to be greater than the equivalent free SOD concentration. Immunofluorescence staining of primary pulmonary fibroblasts extracted from the bleomycin-induced model showed decreased αSMA expression following the in vivo treatment with SOD-overexpressing Bacillus. Our treatment approach SOD through Bacillus spores shows beneficial effects against pulmonary fibrosis, combined with the suppression of the SMAD/TGF-ß pathway, suggesting that it is an effective novel delivery route for antioxidants.

Smartphone application-based rehabilitation in patients with chronic respiratory and cardiovascular diseases: a randomised controlled trial study protocol.

INTRODUCTION: Rehabilitation is well known to improve clinical symptoms and decrease the risk of mortality in patients with chronic respiratory or cardiovascular diseases. We will evaluate the efficacy of smartphone application-based rehabilitation programmes in patients with chronic respiratory or cardiovascular diseases. METHODS AND ANALYSIS: This single-centre single-blind randomised controlled trial will recruit a total of 162 participants from Asan Medical Center (81 patients each for pulmonary and cardiac rehabilitation, respectively). Participants will be assigned to the pulmonary or cardiac rehabilitation groups based on their underlying disease. Participants will be allocated randomly into the intervention or control groups at the ratio of 2:1 (54 and 27 patients). The intervention group will be provided with a smartphone application and undergo smartphone application-based rehabilitation for 12 weeks. The control group will receive the usual outpatient medical treatment without rehabilitation. Participants will be evaluated at baseline and at the end of the rehabilitation. The primary outcomes will be exercise capacity, such as maximal oxygen consumption on cardiopulmonary exercise test for both groups, chronic obstructive pulmonary disease assessment test for the pulmonary rehabilitation group, and Health-related Quality of Life Instrument with 8 Items questionnaires for the cardiac rehabilitation group. The secondary outcomes will include quality of life questionnaires, symptom scores, pulmonary function test and limb muscle test. ETHICS AND DISSEMINATION: The study protocol was approved by the Institutional Review Board of Asan Medical Center. Written informed consent will be obtained from all participants prior to inclusion. The findings from this study will be disseminated through peer-reviewed scientific journals and conferences. TRIAL REGISTRATION NUMBER: NCT05610358.

Effect of smoking on the development of chronic obstructive pulmonary disease in young individuals: a nationwide cohort study.

Background: Cigarette smoking is an important risk factor for developing chronic obstructive pulmonary disease (COPD). However, the effect of smoking on the development of COPD in young individuals remains unclear. We aimed to evaluate the effect of smoking on COPD development in young individuals. Methods: Using the Korean National Health Information Database, we screened individuals aged 20-39 years who participated in the national health check-up between 2009 and 2012. We defined physician-diagnosed COPD based on health insurance claims and searched the database until December 2019. We identified 6,307,576 eligible individuals, and 13,789 had newly developed COPD. We used multivariate Cox proportional hazards models to estimate the adjusted hazard ratio (aHR) of risk factors for COPD. Results: The incidence rate for developing COPD was 0.26/1000 person-year. The risk of developing COPD was significantly higher in current smokers [aHR 1.46, 95% confidence interval (CI) 1.39-1.53] and former smokers (aHR 1.21, 95% CI 1.14-1.29) than in non-smokers. Furthermore, the risk increased with increasing smoking amounts (≥20 pack-years, aHR 2.24; 10-20 pack-years, aHR 1.55; <10 pack-years, aHR 1.27). Female participants had a higher relative risk of developing COPD due to smoking, compared with their male counterparts. Conclusion: Cigarette smoking increased the risk of developing COPD in young individuals. Current and heavy smokers had higher risks of developing COPD than non-smokers. Female smokers were more likely to develop COPD than male smokers.

Value of cardiopulmonary exercise testing in the assessment of symptoms and quality of life in Asian patients with chronic obstructive pulmonary disease.

Background: The natural course of chronic obstructive pulmonary disease (COPD) is characterized by symptom exacerbation and quality-of-life reduction. Therefore, symptoms should be properly assessed. Some studies have demonstrated a weak correlation between cardiopulmonary exercise testing (CPET) parameters and symptoms in patients with COPD; however, data on Asian patients are lacking. We investigated the value of CPET parameters in assessing symptoms and quality of life in Asian patients with COPD. Methods: Of 681 patients who underwent CPET at Asan Medical Center between January 2020 and June 2022, we analyzed 195 patients with COPD in this retrospective study. A cycle ergometer was used for the incremental protocol. The modified Medical Research Council (mMRC) dyspnea scale and COPD Assessment Test (CAT) were administered to assess the patients' symptoms. Results: The mMRC grade was related to maximal oxygen uptake (VO2 max, L/min) (Spearman's correlation coefficient ρ=-0.295, P<0.001) and physiological dead space/tidal volume ratio at peak exercise (VD/VT peak) (ρ=0.256, P<0.001). The CAT score was significantly correlated with VO2 max (L/min) (Spearman's correlation coefficient ρ=-0.297, P<0.001) and VD/VT peak (ρ=0.271, P<0.001), but had no correlation with breathing reserve (ρ=-0.122, P=0.089). The optimal cut-off values of VO2 max and VD/VT peak for predicting the onset of clinically significant dyspnea were 1.099 L/min and 0.295, respectively. Conclusions: VO2 max and VD/VT peak comprehensively reflect the symptoms and health-related quality of life of patients with COPD.

Smoking behavior change and the risk of pneumonia hospitalization among smokers with diabetes mellitus.

Smoking patients with diabetes mellitus (DM) are at greater risk of developing pneumonia. How smoking behavior changes affect the risk of pneumonia hospitalization, however, remains unclear. Therefore, we investigated the association between smoking behavior change and the risk of pneumonia hospitalization in patients with DM. From January 1, 2009 and December 31, 2018, we investigated the association between smoking behavior change and the risk of pneumonia hospitalization in patients with DM. A total of 332,798 adult patients with DM from the Korean National Health Insurance System database who underwent health screening examination between 2009 and 2012, and were smokers at the first health examination were included. During a mean follow-up of 4.89 years, 14,598 (4.39%) incident pneumonia hospitalization cases were identified. Reducers had a slightly increased risk of pneumonia hospitalization (aHR 1.06, 95% CI 1.01-1.10) compared to sustainers. Quitters did not have a significant association with incidence of pneumonia hospitalization. However, increasers had 13% higher risk of pneumonia hospitalization (aHR 1.13, 95% CI 1.07-1.18), regardless of whether initial smoking was light, moderate, or heavy. Our study showed that an increase in smoking intensity was associated with an increased risk of pneumonia hospitalization in people with DM. However, a protective effect of smoking reduction or cessation on pneumonia risk was not demonstrated.

Cancer-Related Dysfunctional Beliefs About Sleep Mediate the Influence of Sleep Disturbance on Fear of Progression Among Patients With Surgically Resected Lung Cancer.

BACKGROUND: Lung cancer is associated with significant psychological distress, including fear of progression (FoP). Because insomnia and depression are highly prevalent and associated with FoP, we examined the association between FoP, insomnia, and depression in cancer patients. Furthermore, we tested the mediation effect of cancer-related dysfunctional beliefs about sleep (C-DBS) on this association. METHODS: We analyzed data collected from patients with surgically resected non-small cell lung cancer from a single-center randomized controlled study investigating digital healthcare applications. Baseline demographic and clinical variables were collected. In addition, self-reported questionnaires including the Fear of Progression Questionnaire-Short Form, Patients Health Questionnaire-9 items (PHQ-9), Insomnia Severity Index, and C-DBS were administered. RESULTS: Among the 320 enrolled patients with lung cancer, a regression model showed that FoP was predicted by age (ß = -0.13, P = 0.007), PHQ-9 (ß = 0.35, P < 0.001), and C-DBS (ß = 0.28, P < 0.001). Insomnia did not directly influence FoP, but C-DBS mediated the association. Depression directly influenced FoP, but C-DBS did not mediate this association. CONCLUSION: Among patients with surgically resected lung cancer, C-DBS mediated the effects of severity of insomnia on FoP. Depression directly influenced FoP, but C-DBS did not influence this association. To reduce FoP among patients with lung cancer, C-DBS should be addressed in the cognitive behavioral therapy module.

Lifestyle practices that reduce seasonal PM2.5 exposure and their impact on COPD.

Particulate matter (PM) is a major air pollutant that has led to global health concerns and can cause and exacerbate chronic obstructive pulmonary disease (COPD). We asked patients with COPD to complete a detailed questionnaire about their lifestyle practices to reduce PM2.5 exposure and analyzed the relationship between ambient PM2.5 concentrations and lifestyle practices. We prospectively enrolled 104 COPD patients from four hospitals in different areas of Korea. They completed detailed questionnaires twice (at enrollment and the end of the study) and Internet of Things-based sensors were installed in their homes to continuously measure PM2.5 for 1 year. The relationship between PM2.5 concentrations, lifestyle practices, and COPD exacerbations were analyzed in each season. The PM2.5 concentration was higher outdoors than indoors in all seasons except summer, and the difference was largest in winter. The six lifestyle practices that significantly lowered the annual indoor PM2.5 concentration compared with the outdoors. The higher the economic status and educational level of patients, the lower the indoor PM2.5 concentration. Some lifestyle practices were associated with reduced small airway resistance, presented as R5-R20 determined by impulse oscillometry, and scores of the St. George's Respiratory Questionnaire. Some lifestyle practices are associated with reduced indoor PM2.5 concentrations and can even affect clinical outcomes, including small airway resistance and quality of life of COPD patients.