COPD Guidelines: A Review of the 2018 GOLD Report

Analysis of Clinical Characteristics and Risk Factors for Drug Resistance in Newly-Treated Patients with Pulmonary Tuberculosis Complicated with Chronic Obstructive Pulmonary Disease

Objective

To analyze the clinical characteristics and risk factors of drug resistance of newly-treated chronic obstructive pulmonary disease (COPD) complicated pulmonary tuberculosis (PTB).

Methods

A total of 489 newly-treated PTB patients admitted to Beijing Geriatric hospital were retrospectively enrolled in this study. Of these, 138 patients with COPD were allocated to the study group, and the remaining 351 patients without COPD were allocated to the control group. The baseline information, clinical characteristics of PTB and drug resistance of Mycobacterium tuberculosis were compared between the two groups. Logistic regression was used to explore the correlation between drug resistance and COPD complications.

Results

Patients complicated with COPD had a higher proportion of respiratory failure, cough, fever and night sweats, chest short breath, and emaciation between the study group and the control group (P<0.05). In terms of medical history, patients complicated with COPD also had a higher proportion of childhood TB history, cough, tuberculosis exposure rate, dust exposure rate, and malnutrition (P<0.05). There were significantly more patients with pulmonary cavities and a delayed diagnosis of TB in the study group than in the control group (P<0.05). The single drug resistance rates of isoniazid, ethambutol, rifampicin, pyrazinamide, and rifapentine, and drug resistance with any two or more drugs in the study group were significantly higher than those in the control group (P<0.05). Multivariate Logistic regression analysis showed that smoking, extrapulmonary tuberculosis, tuberculosis exposure history, malnutrition, pulmonary cavity, and delayed TB diagnosis were risk factors for drug resistance in newly-treated COPD complicated PTB patients.

Conclusion

The symptoms of COPD complicated PTB were more serious. Smoking history, extrapulmonary tuberculosis, tuberculosis exposure history, malnutrition, pulmonary cavity, and delayed diagnosis of tuberculosis were risk factors for TB resistance in these patients.

Fx-Net and PureNet: Convolutional Neural Network architecture for discrimination of Chronic Obstructive Pulmonary Disease from smokers and healthy subjects through electronic nose signals

As one of the most reliable and significant indicators, Chronic Obstructive Pulmonary Disease (COPD) becomes a robust predictor of lung cancer early detection, the world's leading cause of cancer death. One of the methods is to analyze the Volatile Organic Compounds (VOCs) in exhaled breath using electronic noses (E-noses), which have become emerging tools for analyzing breath because of their potential and promising technology for diagnosing. However, the signal processing of the E-Nose sensor becomes vital in exposing information about the subject condition, which most researchers strive to accomplish. We proposed a Convolutional Neural Network (CNN) architecture to classify COPD in smokers and non-smokers, healthy subjects, and smokers from E-Nose signals to contribute to this field. Two models were constructed following E-Nose signal processing state-of-the-arts. One was by combined feature extraction and classifier, and the second was by CNN, which directly processed the raw signal. In addition, various feature extraction and classifier (Machine Learning and CNN) used in prior research were investigated. Using 3K and 5K Fold cross-validation results demonstrated that our proposed models outperformed in Kernel Principal Component Analysis (KPCA) with Fx-ConvNet and Pure-ConvNet. They all reached maximum F1-Score with zero standard deviation values indicating a consistent result. Further experiments also showed that KPCA contributed to the increasing performance of some classifiers with average F1-Score 0.933 and 0.068 as standard deviation values.

The Efficacy and Cost-Effectiveness of Umeclidinium/Vilanterol versus Tiotropium in Symptomatic Patients with Chronic Obstructive Pulmonary Disease

Background

Both long-acting muscarinic antagonists (LAMAs) and long-acting β2-agonists (LABAs) are widely used in the treatment of chronic obstructive pulmonary disease (COPD). A novel LAMA/LABA combination of umeclidinium/vilanterol (UMEC/VI; 62.5 μg/25 μg) is approved for chronic obstructive pulmonary disease (COPD) treatment.

Objective

This study aimed to assess the efficacy and cost-effectiveness of UMEC/VI versus tiotropium (TIO) 18 μg in symptomatic patients with COPD from the perspective of the Chinese National Healthcare System.

Methods

A simple analysis included three studies in the meta-analysis that compared UMEC/VI with TIO. A Markov model was developed to estimate the cost-effectiveness of UMEC/VI compared with TIO treatment in symptomatic patients with COPD. First, utilities, clinical efficacy, and adverse events obtained from the literature were utilized as model inputs. Costs were from Chinese average data, including local data. Costs were expressed in dollars based on 2020 prices. Then, the model outputs including drug costs, other medical costs, and total costs, and quality-adjusted life years (QALYs) were estimated. Costs and outcomes were discounted at a 5% annual rate. Furthermore, incremental cost-effective ratios (ICERs) were analyzed. Finally, the influences of changing parameters on the uncertainty of the results were assessed by means of one-way and probabilistic sensitivity analyses.

Results

This study revealed that UMEC/VI treatment had a higher rate of clinical efficacy in comparison with TIO, and the differences in the rate of adverse events between the two treatments were not significant. The results indicated that UMEC/VI was superior to TIO, which provided an increase in QALYs (0.002) and a total cost savings of $765.67 per patient over 3 years. In the base case, the ICER of UMEC/VI is -$397468.04/QALY compared with TIO, suggesting that UMEC/VI may be considered a dominant option over TIO. According to the Chinese medical system, the probability of UMEC/VI being cost-effective was 61.6% at a willingness-to-pay (WTP) of $31554/QALY. Sensitivity analyses confirmed that the results were robust.

Conclusion

UMEC/VI could be considered a cost-effective treatment compared with TIO in symptomatic COPD patients from the Chinese National Healthcare System perspective. These results may help decision-makers in China when making judgements on which treatments to administer.

Elevated risk of acute epiglottitis in patients with chronic obstructive pulmonary disease: A nationwide cohort study

Objective

In individuals with epiglottitis, chronic obstructive pulmonary disease (COPD) is a common comorbidity; however, the impact of COPD under such circumstances is not well documented. Therefore, we performed this population-based study to determine whether, in adults, COPD is a risk factor for epiglottitis.

Methods

In this retrospective matched-cohort study, data obtained from the Taiwan National Health Insurance Research Database were analyzed. We identified all patients newly diagnosed as having COPD in 2000–2011 and performed frequency matching and propensity-score matching for every patient with COPD individually to another patient without a COPD diagnosis. We used epiglottitis occurrence as the study endpoint, and we investigated the hazard ratio of epiglottitis by using the Cox proportional hazards model after adjustment for potential confounders.

Results

In the frequency matching, the cumulative epiglottitis incidence was significantly higher (p = 0.005) in the COPD cohort. According to the adjusted Cox proportional hazard model, COPD exhibited a significant association with elevated epiglottitis incidence (adjusted hazard ratio: 1.76; 95% confidence interval: 1.15–2.70, p = 0.009). Similar trend was observed in the propensity-score matching analysis (adjusted hazard ratio: 1.50; 95% confidence interval: 0.99–2.29, p = 0.057). Our subgroup analysis revealed COPD to be an epiglottitis risk factor in male patients and those aged 40–64 years.

Conclusions

This is the first nationwide matched-cohort research to examine the association of COPD with epiglottitis. Our results revealed that COPD may be a potential risk factor for epiglottitis; thus, clinicians should be mindful of the potential increased risk of epiglottitis following COPD.

Bufei Decoction Improves Lung-Qi Deficiency Syndrome of Chronic Obstructive Pulmonary Disease in Rats by Regulating the Balance of Th17/Treg Cells

Bufei decoction (BFD) has been applied to treat chronic obstructive pulmonary disease (COPD) for centuries as a recognized traditional Chinese herbal formula. However, mechanisms of BFD on COPD are unclear. This study conducts an inquiry into the underlying mechanisms of the therapeutic effect of BFD on COPD. A COPD rat model with qi deficiency in lungs was established through induction using cigarette and sawdust smoking combined with intratracheal instillation of lipopolysaccharide following BFD treatment for 28 days. Changes in Th17/Treg cells of COPD rats with the syndrome of lung qi deficiency after BFD administration were verified using pulmonary function, ELISA, flow cytometry, histopathology, and Western blotting assays. The findings showed that BFD protected COPD rats from decreased lung function and lung injury. BFD administration reduced proinflammatory cytokines IL-6 and IL-17 secretion, promoted inhibitory cytokines IL-10 and TGF-β secretion, decreased Th17/Treg cell ratio, markedly downregulated the Th17 cell transcription factor ROR-γt expression, and upregulated transcription factor Foxp3 expression in Treg cells. We speculate that lung tonic soup improved pulmonary qi deficiency in rats with COPD by regulating the balance of Th17/Treg cells.

Transnasal High-Flow Oxygen Therapy versus Noninvasive Positive Pressure Ventilation in the Treatment of COPD with Type II Respiratory Failure: A Meta-Analysis

Objective

To compare the safety and efficacy of transnasal high-flow oxygen therapy (HFNT) and noninvasive positive pressure ventilation (NIV) in the treatment of chronic obstructive pulmonary disease (COPD) with type II respiratory failure.

Methods

PubMed, the Cochrane Library, Embase, CBM, CNKI, and other databases were searched for randomized controlled trials (RCTS) on the efficacy of HFNT and NIV in the treatment of COPD. Meta-analysis was conducted using RevMan 5.3 software after two researchers screened literatures, extracted data, and evaluated the methodological quality of the included studies according to inclusion and exclusion criteria.

Results

A total of 948 patients were included in 12 RCTS. Comprehensive analysis results showed that the HFNC group had higher levels of 12 h-PAO2, 48 h-PACO2 and, 48 h-pH than the NIV group, and the differences were statistically significant (P < 0.05). There were no significant differences in 24 h-PAO2 and 72 h-PAO2, 12 h-PACO2, 24 h-PACO2 and 72 h-PACO2, 24 h-pH, 48 h-pH, and 72 h-pH between the two groups after treatment (P > 0.05).

Conclusions

Compared with NIV, HFNC does not increase the treatment failure rate in COPD patients with type II respiratory failure, and HFNC has better comfort and tolerance, which is a new potential respiratory support treatment for COPD patients with type II respiratory failure.

Molecular and Clinicopathological Characteristics of Lung Cancer Concomitant Chronic Obstructive Pulmonary Disease (COPD)

Introduction

Chronic obstructive pulmonary disease (COPD) and lung cancer often coexist, but its pathophysiology and genomics features are still unclear.

Methods

In this study, we retrospectively collected lung cancer concomitant COPD (COPD-LC) and non-COPD lung cancer (non-COPD-LC) patients, who performed next generation sequencing (NGS) and had clinicopathological information simultaneously. The COPD-LC data from the TCGA cohort were collected to conduct further analysis.

Results

A total of 51 COPD-LC patients and 88 non-COPD-LC patients were included in the study. Clinicopathological analysis showed that proportion of male gender, older age, and smoking patients were all substantially higher in COPD-LC group than in non-COPD-LC group (all P<0.01). Comparing the genomic data of the two groups in our cohort, COPD-LC had higher mutation frequency of LRP1B (43% vs 9%, P = 0.001), EPHA5 (24% vs 1%, P = 0.002), PRKDC (14% vs 1%, P = 0.039), PREX2 (14% vs 0%, P = 0.012), and FAT1 (14% vs 0%, P = 0.012), which had a relationship with improved tumor immunity. Immunotherapy biomarker of PD-L1 positive expression (62.5% vs 52.0%, P = 0.397) and tumor mutation burden (TMB, median TMB: 7.09 vs 2.94, P = 0.004) also were higher in COPD-LC. In addition, RNA data from TCGA further indicated tumor immunity increased in COPD-LC. Whereas, COPD-LC had lower frequency of EGFR mutation (19% vs 50%, P = 0.013) and EGFR mutant COPD-LC treated with EGFR-TKI had worse progression-free survival (PFS) (HR = 3.52, 95% CI: 1.27–9.80, P = 0.01).

Conclusion

In this retrospective study, we first explored molecular features of COPD-LC in a Chinese population. Although COPD-LC had lower EGFR mutant frequency and worse PFS with target treatment, high PD-L1 expression and TMB indicated these patients may benefit from immunotherapy.

Quantitative Evaluation of Chronic Obstructive Pulmonary Disease and Risk Prediction of Acute Exacerbation by High-Resolution Computed Tomography

Objective

It is imperative to popularize the tertiary prevention of chronic obstructive pulmonary disease (COPD) and to improve the diagnosis and treatment.

Methods

COPD patients were divided into mild (n = 18), moderate (n = 20), severe (n = 24), and extremely severe (n = 22) groups for performing high-resolution computed tomography (HRCT) and pulmonary function test. Serum procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP) were detected, and the occurrence rate of acute exacerbation COPD (AECOPD) was recorded during a 12-months follow-up period.

Results

With an increase in the severity grade, the HRCT indexes, including emphysema index (EI), 1st and 15th percentile of inspiratory attenuation distribution (Perc1 and Perc15), ratio of expiratory/inspiratory mean lung density (MLD_ex/in) and lung volume (LV_ex/in), and ratio of the wall thickness to the outer diameter of the lumen (TDR), as well as percentage of the wall area to the total cross-sectional area (WA%) were increased with a decreased change in relative lung volume with attenuation values between −860 and −950 HU (RVC_{−860to −950}) and lumen area (A_i). These were correlated with the ratio of forced expiratory volume in 1 sec (FEV1) over forced vital capacity (FVC) (FEV1/FVC), the percentage of FEV1 the predicted value (FEV1%), and ratio of residual volume to total lung volume (RV/TLC). Body mass index, MLD_ex/in, FEV1%, FEV1/FVC, and PCT had a predictive value to AECOPD, with the combined AUC of 0.812.

Conclusions

HRCT imaging effectively classifies the severity of COPD, which combined with BMI, PFT, and serum PCT can predict the risk of AECOPD.

Complex Evaluation of Surfactant Protein A and D as Biomarkers for the Severity of COPD

Purpose

Pulmonary surfactant proteins A (SP-A) and D (SP-D) are lectins, involved in host defense and regulation of pulmonary inflammatory response. However, studies on the assessment of COPD progress are limited.

Patients and Methods

Pulmonary surfactant proteins were obtained from the COPD mouse model induced by cigarette and lipopolysaccharide, and the specimens of peripheral blood and bronchoalveolar lavage (BALF) in COPD populations. H&E staining and RT-PCR were performed to demonstrate the successfully established of the mouse model. The expression of SP-A and SP-D in mice was detected by Western Blot and immunohistochemistry, while the proteins in human samples were measured by ELISA. Pulmonary function test, inflammatory factors (CRP, WBC, NLR, PCT, EOS, PLT), dyspnea index score (mMRC and CAT), length of hospital stay, incidence of complications and ventilator use were collected to assess airway remodeling and progression of COPD.

Results

COPD model mice with emphysema and airway wall thickening were more prone to have decreased SP-A, SP-D and increased TNF-α, TGF-β, and NF-kb in lung tissue. In humans, SP-A and SP-D decreased in BALF, but increased in serum. The serum SP-A and SP-D were negatively correlated with FVC, FEV1, FEV1/FVC, and positively correlated with CRP, WBC, NLR, mMRC and CAT scores (P < 0.05, respectively). The lower the SP-A and SP-D in BALF, the worse the lung function and the increased probability of complications and ventilator use. Moreover, the same trend emerged in COPD patients grouped according to GOLD severity grade (Gold 1–2 group vs Gold 3–4 group). The worse the patient’s condition, the more pronounced the change.

Conclusion

This study suggests that SP-A and SP-D may be related to the progression and prognostic evaluation of COPD in terms of airway remodeling, inflammatory response and clinical symptoms, and emphasizes the necessity of future studies of surfactant protein markers in COPD.

Antibiotic resistance in chronic respiratory diseases: from susceptibility testing to the resistome

The development of resistome analysis, i.e. the comprehensive analysis of antibiotic-resistance genes (ARGs), is enabling a better understanding of the mechanisms of antibiotic-resistance emergence. The respiratory microbiome is a dynamic and interactive network of bacteria, with a set of ARGs that could influence the response to antibiotics. Viruses such as bacteriophages, potential carriers of ARGs, may also form part of this respiratory resistome. Chronic respiratory diseases (CRDs) such as cystic fibrosis, severe asthma, chronic obstructive pulmonary disease and bronchiectasis, managed with long-term antibiotic therapies, lead to multidrug resistance. Antibiotic susceptibility testing provides a partial view of the bacterial response to antibiotics in the complex lung environment. Assessing the ARG network would allow personalised, targeted therapeutic strategies and suitable antibiotic stewardship in CRDs, depending on individual resistome and microbiome signatures. This review summarises the influence of pulmonary antibiotic protocols on the respiratory microbiome, detailing the variable consequences according to antibiotic class and duration of treatment. The different resistome-profiling methods are explained to clarify their respective place in antibiotic-resistance analysis in the lungs. Finally, this review details current knowledge on the respiratory resistome related to therapeutic strategies and provides insight into the application of resistome analysis to counter the emergence of multidrug-resistant respiratory pathogens.

Lung Resections for Elderly Patients with Lung Metastases: A Comparative Study of the Postoperative Complications and Overall Survival

Background: Pulmonary metastasectomy (PM) is an established treatment option for selected patients with stage IV solid tumors. The aim of this study was to investigate the feasibility of and survival rate in PM for elderly patients. Methods: We retrospectively analyzed all of the patients who underwent PM with curative intention at our institution. The patients were categorized into two groups: the elderly group (≥70 years old) and the non-elderly group (<70 years old). Results: The elderly group consisted of 222 patients versus 538 patients in the non-elderly group. The median number of resected metastases was 2 ± 3 in the elderly group and 4 ± 5 in the non-elderly group (p < 0.01). No difference in the rate of postoperative complications was observed between the two groups (p = 0.3). The median length of hospital stay in each group was comparable (10 ± 5 vs. 10 ± 4.3 days, p = 0.3). The 5-year survival rate was 67% in the elderly group and 78% in the non-elderly group (p = 0.117). In the univariate analysis, COPD was associated with poor survival in the elderly group (p = 0.002). Conclusion: The resection of pulmonary metastases in elderly patients is safe, is not associated with increased risks of postoperative complication, and the survival benefit is not reduced in selected patients.

Role of CD4+ T and CD8+ T Lymphocytes-Mediated Cellular Immunity in Pathogenesis of Chronic Obstructive Pulmonary Disease

This work was to explore the changes of T lymphocyte subsets in peripheral blood of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) (AECOPD) and the role of cellular immunity mediated in the disease process. Eighty-six patients with AECOPD who visited Qingdao Hiser Medical Center from June 2020 to December 2021 and 30 healthy people (controls) who underwent health examination in the same period were selected. The differences of pulmonary function (PF), arterial blood gas (ABG), blood routine inflammatory indexes, T lymphocyte and T lymphocyte subsets were compared between the two groups, and the correlation between T lymphocyte subsets and each index was analyzed. There were clear differences in PF, ABG, and PB inflammation indexes between AECOPD patients and the controls (P <0.05). Compared with the controls, the CD₄⁺ and CD₄⁺/CD₈⁺ ratio in PB of AECOPD group were obviously decreased, and the CD₈⁺ level was clearly increased (P <0.05); Th1 of CD₄⁺ cell subsets and Tc1 of CD₈⁺ cell subsets were significantly increased, while Th2 of CD₄⁺ cell subsets and Tc2 of CD₈⁺ cell subsets were obviously decreased (P <0.05). However, CD4⁺ was significantly positively correlated with lung function indexes, and significantly negatively correlated with neutrophils/lymphocytes and high-sensitivity C-reactive protein (P <0.05) and significantly positively correlated with Hs-CRP (P <0.05). In summary, CD4+ and CD8⁺ T lymphocytes were involved in the occurrence and occurrence of AECOPD, the decrease of CD4⁺ and the increase of CD8⁺ may promote the deterioration of COPD.

Lung Spatial Profiling Reveals a T Cell Signature in COPD Patients with Fatal SARS-CoV-2 Infection

People with pre-existing lung diseases such as chronic obstructive pulmonary disease (COPD) are more likely to get very sick from SARS-CoV-2 disease 2019 (COVID-19). Still, an interrogation of the immune response to COVID-19 infection, spatially throughout the lung structure, is lacking in patients with COPD. For this study, we characterized the immune microenvironment of the lung parenchyma, airways, and vessels of never- and ever-smokers with or without COPD, all of whom died of COVID-19, using spatial transcriptomic and proteomic profiling. The parenchyma, airways, and vessels of COPD patients, compared to control lungs had (1) significant enrichment for lung-resident CD45RO⁺ memory CD4⁺ T cells; (2) downregulation of genes associated with T cell antigen priming and memory T cell differentiation; and (3) higher expression of proteins associated with SARS-CoV-2 entry and primary receptor ubiquitously across the ROIs and in particular the lung parenchyma, despite similar SARS-CoV-2 structural gene expression levels. In conclusion, the lung parenchyma, airways, and vessels of COPD patients have increased T-lymphocytes with a blunted memory CD4 T cell response and a more invasive SARS-CoV-2 infection pattern and may underlie the higher death toll observed with COVID-19.

REducing delay through edUcation on eXacerbations for people with chronic lung disease: Study protocol of a single-arm pre-post study

AIM

This study protocol aims to examine the effectiveness and preconditions of a self-management program-named REducing Delay through edUcation on eXacerbations (REDUX)-in China.

BACKGROUND

The high disease burden in people with chronic lung disease is mainly due to exacerbations. There is a need for effective exacerbation-management interventions. A nurse-led program, REDUX, helped patients self-manage exacerbations.

DESIGN

A single-arm pre-post study.

METHODS

Fifty-four patients and 24 healthcare professionals (HCPs) in Chinese primary care will be included. The core element of the program is a personalized action plan. HCPs will receive training in using the action plan to help patients manage exacerbations. The intervention will start when a patient is referred to the nurse for a post-exacerbation consultation and ends when the patient presents for the second post-exacerbation consultation. During the first post-exacerbation consultation, the patient and nurse will create the action plan. The primary outcomes in patients will include the delays between the onset of exacerbation and recognition, between exacerbation recognition and action, between exacerbation recognition and consultation with a doctor, and when the patients feel better after receiving medical help from HCPs. The secondary outcomes will include preconditions of the program. The ethics approval was obtained in September 2021.

DISCUSSION

This study will discuss a culturally adapted nurse-led self-management intervention for people with chronic lung disease in China. The intervention could help Chinese HCPs provide efficient care and reduce their workload. Furthermore, it will inform future research on tailoring nurse-led self-management interventions in different contexts.

IMPACT

The study will contribute to the evidence on the effectiveness and preconditions of REDUX in China. If effective, the result will assist the nursing of people with chronic lung disease.

TRIAL REGISTRATION

Registered in the Chinese clinical trial registry (ID: 2100051782).

Associations between bone mineral density and chronic obstructive pulmonary disease

Objective

To assess the relationship between chronic obstructive pulmonary disease (COPD) severity and bone mineral density (BMD) in the whole body and different body areas.

Methods

This retrospective, cross-sectional study included patients with COPD. Demographic and lung function data, COPD severity scales, BMD, and T scores were collected. Patients were grouped by high (≥–1) and low (<–1) T scores, and stratified by body mass index, airway obstruction, dyspnoea, and exercise capacity (BODE) index. The relationship between whole-body BMD and BODE was evaluated by Kendall’s tau-b correlation coefficient. Risk factors associated with COPD severity were identified by univariate analyses. BMD as an independent predictor of severe COPD (BODE ≥5) was verified by multivariate logistic regression. BMD values in different body areas for predicting severe COPD were assessed by receiver operating characteristic curves.

Results

Of 88 patients with COPD, lung-function indicators and COPD severity were significantly different between those with high and low T scores. Whole-body BMD was inversely related to COPD severity scales, including BODE. Multivariate logistic regression revealed that BMD was independently associated with COPD severity. The area under the curve for pelvic BMD in predicting severe COPD was 0.728.

Conclusion

BMD may be a novel marker in predicting COPD severity, and pelvic BMD may have the strongest relative predictive power.

Patients with Chronic Obstructive Pulmonary Disease Can Accurately Perform Home-Based Measurements of Inspiratory Capacity and Dynamic Hyperinflation

Home-based lung function measurements can be used to capture day-to-day variations in symptoms in patients with chronic obstructive pulmonary disease (COPD). Although dynamic hyperinflation (DH) is clinically relevant, existing home-based measurements do not include its assessment. DH can be measured through inspiratory capacity (IC) measurements before and after metronome-paced tachypnea test (MPT). The goal of this study is to determine the accuracy of unsupervised home-based IC and DH measurements in COPD.Sixteen COPD patients performed IC and DH measurements during 4 home visits. Visit 1 was considered a training session. During all visits supervised and unsupervised IC at rest (IC_REST) and after MPT (IC_MPT) were measured. DH was calculated as the difference between IC_REST and IC_MPT, and as a percentage of IC_REST. Bland-Altman analyses and ANOVA tests were performed to determine the effect of supervision and repeated measures over time.The biases between supervised and unsupervised IC_REST, IC_MPT, ΔIC and ΔIC% were 0.007 L, 0.007 L, 0 mL and -0.09% in the last visit, respectively. Limits of agreement of IC_REST and ΔIC% decreased from ±0.261 mL to ±0.201 mL, and from ±13.84% to ±10.81% between visit 1 and 4, respectively. No significant effect of supervision or over time was found.After a robust training and a learning phase, COPD patients are able to perform IC measurements in an accurate manner in both rest and after MPT. This yield accurate assessment of DH, in an unsupervised home-based setting.

Prognostic value of key variables from cardiopulmonary exercise testing in patients with COPD: 42-month follow-up

AIM

To identify better predictors of early death in patients with chronic obstructive pulmonary disease (COPD) using potential predictors derived from key measures obtained from cardiopulmonary exercise testing (CPET).

METHODS

This is a prospective, cohort study with 42-month follow-up in 126 COPD patients. Every patient completed the clinical evaluation, followed by a pulmonary function test and CPET. CPET was performed on a cycle ergometer with electromagnetic braking and ventilatory expired analysis was measured breath-by-breath using a computer-based system. Peak oxygen consumption (V̇O_2, mlO_2. kg^-1_. min^-1), minute ventilation/carbon dioxide production and the, minute ventilation (V̇_E, L/min), and the V̇_E/carbon dioxide production (V̇_E/V̇CO₂) slope were obtained from CPET.

RESULTS

48 (38%) patients died during the 42-month follow-up. Kaplan Meier analysis revealed a V̇_E/V̇CO₂ slope ≥30, peak V̇_E ≤ 25.7L/min and peak V̇O₂ ≤ 13.8 mlO_2. kg^-1_. min^-1were strong predictors of mortality in COPD patients. Cox regression revealed that the V̇O₂ peak ≤13.8 mlO_2. kg^-1_. min^-1 (CI 95% 0.08-0.93), V̇_E/V̇CO₂ slope ≥30 (CI 95% 0.07-0.94), V̇_E peak ≤25.7 L/min (CI 95% 0.01-0.15), Sex (CI 95% 0.04-0.55) and Age (CI 95% 1.03-1.2) were the main predictors of mortality risk.

CONCLUSION

Diminished exercise capacity and peak ventilation as well as ventilatory inefficiency are independent prognostic markers. Similar to patients with heart failure, CPET may be a valuable clinical assessment in the COPD population.

[Consistency analysis and clinical guiding significance of cytomegalovirus nucleic acid and antibody detections in patients with different clinical characteristics]

OBJECTIVE

To investigate the consistency of cytomegalovirus deoxyribo nucleic acid (CMV-DNA) and immunoglobulin M (IgM) antibody detections in patients with different clinical characteristics and their guiding value for clinical practice.

METHODS

From December 2014 to November 2019, a total of 507 patients who were detected with both CMV-IgM and CMV-DNA were collected in Peking University International Hospital. Their general information, such as gender, age and clinical data, including the patient's diagnosis, medication, and outcome were also collected. The groups were stratified according to whether CMV-DNA was negative or positive, CMV-IgM was negative or positive, age, gender, and whether they received immunosuppressive therapy or not. The Pearson Chi-square test or Fisher's exact test was used for comparison of the rates between the groups. P < 0.05 means the difference is statisti-cally significant.

RESULTS

Of the 507 patients submitted for examination, 55 (10.85%) were positive for CMV-DNA, 74 (14.60%) were positive for CMV-IgM, and 20 (3.94%) were positive for both CMV-DNA and CMV-IgM. Of the 55 patients with CMV-DNA positive, 37 were male, accounting for 67.27%. In addition, 25 patients were older than 60 years, accounting for 45.45% and 33 patients received immunosuppressive therapy, accounting for 60%. The rates were higher than that of CMV-DNA negative group, 47.35% (P=0.005), 68.14% (P=0.043), 46.02% (P=0.050), respectively. Of the patients with both CMV-DNA and IgM positive, 45% received immunosuppressive threapy, which was lower than that of CMV-DNA positive but IgM negative patients (68.57%, P=0.086), and also lower than CMV-DNA negative but IgM positive patients (68.52%, P=0.064). In the patients with both CMV-DNA and IgM positive, 91.67% showed remission after receiving ganciclovir, whereas in the patients with CMV-DNA positive but IgM negative, the rate was only 60% (P=0.067).

CONCLUSION

CMV-IgM antibody detection is affected by age, gender, and immune status. It is not recommended to use CMV-IgM alone to determine CMV infection in patients with immunosuppressive status and those older than 60 years. CMV-DNA and CMV-IgM combined detection may help to predict patients' immune status and outcomes of antiviral therapy.

Association of 71 cardiovascular disease-related plasma proteins with pulmonary function in the community

RATIONALE

It has been speculated that shared mechanisms underlie respiratory and cardiovascular diseases (CVD) including systemic inflammation or mutual risk factors. In this context, we sought to examine the associations of CVD-related plasma proteins with lung function as measured by spirometry in a large community-based cohort of adults.

METHODS

The study included 5777 Framingham Heart Study participants who had spirometry and measurement of 71 CVD-related plasma proteins. The association of plasma proteins with lung function was assessed cross-sectionally and longitudinally using models accounting for familial correlations. Linear mixed models were used for the following measurements: FEV1%predicted, FVC%predicted, and FEV1/FVC ratio with secondary analyses examining obstructive and restrictive physiology at baseline and their new onset during follow up.

MEASUREMENTS AND MAIN RESULTS

Among the 71 CVD-related plasma proteins, 13 proteins were associated in cross-sectional analyses with FEV1%predicted, 17 proteins were associated with FVC%predicted, and 1 protein was associated with FEV1/FVC. The proteins with the greatest inverse relations to FEV1%predicted and FVC%predicted included leptin, adrenomedullin, and plasminogen activator inhibitor-1; in contrast there were three proteins with positive relations to FEV1%predicted and FVC%predicted including insulin growth factor binding protein 2, tetranectin, and soluble receptor for advanced glycation end products. In longitudinal analyses, three proteins were associated with longitudinal change in FEV1 (ΔFEV1) and four with ΔFVC; no proteins were associated with ΔFEV1/FVC.

CONCLUSION

Our findings highlight CVD-related plasma proteins that are associated with lung function including markers of inflammation, adiposity, and fibrosis, representing proteins that may contribute both to respiratory and CVD risk.

Extracellular vesicles and chronic obstructive pulmonary disease (COPD): a systematic review

Background

Chronic Obstructive Pulmonary Disease (COPD) is a common inflammatory disease of the airways characterized by irreversible airflow limitation, ranking the third highest cause of death worldwide. Extracellular vesicles (EVs) are important intercellular communication mediators released by cells into their extracellular environment with the capacity to transfer biological signals. EVs involved in COPD hold great potential to understand disease pathogenesis and identify important biomarkers. This systematic review aims to examine all available research on EVs in the pathogenesis and diagnosis of COPD to identify existing knowledge and support further research within the field.

Methods

Publications were searched using PubMed and EMBASE with the search terms (Exosomes or extracellular vesicles or microvesicles or microparticles or ectosomes) AND (chronic obstructive pulmonary disease or COPD or emphysema or bronchitis).

Results

Initial search yielded 512 papers of which 142 were manually selected for review and 43 were eligible for analyses. The studies were divided into groups according to the role of EVs in pathogenesis, EV origin and cargo, their role in COPD exacerbations and their diagnostic utility. EVs were found to be involved in the mechanism of pathogenesis of COPD, derived from various cell types, as well as containing modified levels of miRNAs. EVs also varied according to the pathophysiological status of disease, therefore presenting a possible method for COPD diagnosis and progress monitoring.

Conclusion

The current findings show the limited but good quality research looking at the role of EVs in COPD, demonstrating the need for more studies to better define and provide further insight into the functional characteristics of EV in COPD pathogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01984-0.

Association between body composition, sarcopenia and pulmonary function in chronic obstructive pulmonary disease

Background

Chronic Obstructive Pulmonary Disease (COPD) is characterized by progressive and irreversible airflow limitation. Different factors that modify pulmonary function include age, sex, muscular strength, and a history of exposure to toxic agents. However, the impact of body composition compartments and sarcopenia on pulmonary function is not well-established. This study aimed to evaluate how body composition compartments and sarcopenia affect pulmonary function in COPD patients.

Methods

In a cross-sectional study, patients with a confirmed diagnosis of COPD, > 40 years old, and forced expiratory volume in the first second /forced vital capacity ratio (FEV₁/FVC) < 0.70 post-bronchodilator were included. Patients with cancer, HIV, and asthma were excluded. Body composition was measured with bioelectrical impedance. Sarcopenia was defined according to EWGSOP2, and pulmonary function was assessed by spirometry.

Results

185 patients were studied. The mean age was 72.20 ± 8.39 years; 55.14% were men. A linear regression adjusted model showed associations between body mass index, fat-free mass, skeletal muscle mass index, appendicular skeletal muscle mass index, and phase angle (PhA), and sarcopenia with FEV₁ (%). As regards FVC (%), PhA and exercise tolerance had positive associations.

Conclusion

Body composition, especially PhA, SMMI, ASMMI, and sarcopenia, has a significant impact on pulmonary function. Early detection of disturbances of these indexes enables the early application of such therapeutic strategies in COPD patients.

The Relationship of Partial Pressure of Carbon Dioxide (PaCO2) with Disease Severity Indicators Such as BODE and GOLD in Hospitalized COPD Patients

Purpose

This study aimed to investigate the relationship of partial pressure of carbon dioxide (PaCO2) with BODE and GOLD in stable COPD subjects and to explore the predictive value of PaCO2 for severe COPD (BODE index score ≥5 or GOLD index score ≥3). Patients and Methods. In total, 80 participants with COPD and free from other conditions affecting PaCO2 were recruited. Arterial blood gases, BODE, GOLD, SGRQ, lung function, and other data were collected. The BODE index was calculated, and patients were divided into two groups according to the BODE index and PaCO2 median, respectively. We used Pearson's correlation test and the receiver operating characteristic curves to evaluate the utility of PaCO2. Besides, the univariate and multivariate logistic regression analyses were conducted to verify whether PaCO2 was an independent factor associated with BODE grades.

Results

COPD subjects with BODE ≥5 and GOLD ≥3 had significantly higher levels of PaCO2 (p = 0.004, p = 0.001, respectively). In the high PaCO2 group, patients underwent poorer outcomes than the low PaCO2 group. PaCO2 was negatively correlated with forced expiratory volume in 1 second in percent of the predicted value (FEV1%) (r = -0.612, p < 0.001). The performance of PaCO2 levels in predicting BODE ≥5 and GOLD ≥3 was 0.748 and 0.755, respectively. The logistic regression analyses proved that PaCO2 was associated with BODE ≥5 in COPD patients (odds ratio = 1.160, 95% CI: 1.025-1.313, p = 0.019).

Conclusions

A higher level of PaCO2 was associated with a higher index for BODE or GOLD in COPD and had the predictive value for severe COPD.

Role of nuclear factor erythroid 2-related factor 2 in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation due to chronic airway inflammation and destruction of the alveolar structure from persistent exposure to oxidative stress. The body has various antioxidant mechanisms for efficiently coping with such oxidative stress. The nuclear factor erythroid 2-related factor 2 (Nrf2)–antioxidant response element (ARE) is a representative system. Dysregulation of the Nrf2-ARE pathway is responsible for the development and promotion of COPD. Furthermore, COPD severity is also closely related to this pathway. There has been a clinical impetus to use Nrf2 for diagnostic and therapeutic purposes. Therefore, in this work, we systematically reviewed the clinical significance of Nrf2 in COPD patients, and discuss the value of Nrf2 as a potential COPD biomarker.

Diagnostic efficacy of visual subtypes and low attenuation area based on HRCT in the diagnosis of COPD

Background

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease. Current gold standard criteria, pulmonary function tests (PFTs) may result in underdiagnosis of potential COPD patients. Therefore, we hypothesize that the combination of high-resolution computed tomography (HRCT) and clinical basic characteristics will enable the identification of more COPD patients.

Methods

A total of 284 patients with respiratory symptoms who were current or former smokers were included in the study, and were further divided into 5 groups of GOLD grade I–IV and non-COPD according to PFTs. All patients underwent inspiratory HRCT scanning and low attenuation area (LAA) was measured. Then they were divided into seven visual subtypes according to the Fleischner Society classification system. Non-parametric tests were used for exploring differences in basic characteristics and PFTs between different groups of enrolled patients and visual subtypes. Binary logistic regression was to find the influencing factors that affected the patients’ outcome (non-COPD vs GOLD I-IV). The area under the receiver operating characteristic curve (AUC-ROC) was to explore the diagnostic efficacy of LAA, visual subtypes, and combined basic characteristics related to COPD for COPD diagnosis. Finally, based on the cut-off values of ROC analysis, exploring HRCT features in patients who do not meet the diagnostic criteria but clinically suspected COPD.

Results

With the worsening severity of COPD, the visual subtypes gradually progressed (p < 0.01). There was a significant difference in LAA between GOLD II–IV and non-COPD (p < 0.0001). The diagnostic efficacy of LAA, visual subtypes, and LAA combined with visual subtypes for COPD were 0.742, 0.682 and 0.730 respectively. The diagnostic efficacy increased to 0.923–0.943 when basic characteristics were added (all p < 0.001). Based on the cut-off value of ROC analysis, LAA greater than 5.6, worsening of visual subtypes, combined with positive basic characteristics can help identify some potential COPD patients.

Conclusion

The heterogeneous phenotype of COPD requires a combination of multiple evaluation methods. The diagnostic efficacy of combining LAA, visual subtypes, and basic characteristics achieves good consistency with current diagnostic criteria.

Benefit of Prompt versus Delayed Use of Single-Inhaler Fluticasone Furoate/Umeclidinium/Vilanterol (FF/UMEC/VI) Following a COPD Exacerbation

Purpose

Triple therapy (TT; inhaled corticosteroid, long-acting muscarinic antagonist, and long-acting β₂-agonist) is recommended for patients with chronic obstructive pulmonary disease (COPD) at risk of exacerbation, although the optimum timing of TT initiation remains unclear. This study evaluated the impact of prompt versus delayed initiation of single-inhaler TT (fluticasone furoate, umeclidinium, and vilanterol [FF/UMEC/VI]) following a COPD exacerbation.

Patients and Methods

This retrospective cohort study used data from the IQVIA PharMetrics^® Plus database. Patients initiating FF/UMEC/VI following a COPD exacerbation between September 18, 2017 and September 30, 2019 (exacerbation = index date) were categorized as prompt (within 30 days of index) or delayed (31–180 days after index) FF/UMEC/VI initiators. Patients were aged ≥40 years at index, had ≥12 months’ continuous health insurance coverage before index (baseline), and ≥6 months’ coverage after index (follow-up). Patients with a COPD exacerbation or claim for FF/UMEC/VI during baseline were excluded. Inverse probability weighting was used to adjust for differences in baseline characteristics between cohorts. Exacerbations (overall, moderate, and severe), healthcare costs, and readmissions were evaluated during follow-up.

Results

A total of 1904 patients (prompt: 529; delayed: 1375) were included. After weighting, baseline characteristics were well balanced between cohorts. Patients in the prompt cohort had significantly lower rates per person-year (PPY) of overall (0.98 vs 1.23; rate ratio [RR] [95% CI] = 0.79 [0.65–0.94], p = 0.004), moderate (0.86 vs 1.03; RR [95% CI] = 0.84 [0.69–0.99], p = 0.038), and severe (0.11 vs 0.20; RR [95% CI] = 0.57 [0.37–0.79], p = 0.002) exacerbations, compared with delayed initiators. Mean all-cause and COPD-related healthcare costs were significantly lower among prompt initiators (all-cause: $26,107 vs $32,400 PPY, p = 0.014; COPD-related: $12,694 vs $17,640 PPY, p = 0.002).

Conclusion

Prompt initiation of FF/UMEC/VI following a moderate or severe COPD exacerbation was associated with significant reductions in exacerbations and healthcare costs relative to delayed initiation.

Urinary Metals, Arsenic, and Polycyclic Aromatic Hydrocarbon Exposure and Risk of Self-reported Emphysema in the US Adult Population

PURPOSE

Metal and chemical exposure can cause acute and chronic respiratory diseases in humans. The purpose of this analysis was to analyze 14 types of urinary metals including mercury, uranium, tin, lead, antimony, barium, cadmium, cobalt, cesium, molybdenum, manganese, strontium, thallium, tungsten, six types of speciated arsenic, total arsenic and seven forms of polycyclic aromatic hydrocarbons (PAHs), and the link with self-reported emphysema in the US adult population.

METHODS

A cross-sectional analysis using the 2011-2012, 2013-2014 and 2015-2016 National Health and Nutrition Examination Survey datasets was conducted. A specialized weighted complex survey design analysis package was used in analyzing the data. Multivariate logistic regression models were used to assess the association between urinary metals, arsenic, and PAHs and self-reported emphysema among all participants and among non-smokers only. Models were adjusted for lifestyle and demographic factors.

RESULTS

A total of 4,181 adults were analyzed. 1-Hydroxynaphthalene, 2-hydroxynaphthalene, 3-hydroxyfluorene, 2-hydroxyfluorene, 1-hydroxypyrene, and 2 & 3-hydroxyphenanthrene were positively associated with self-reported emphysema. Positive associations were also observed in cadmium and cesium with self-reported emphysema. Among non-smokers, quantiles among 2-hydroxynaphthalene, arsenocholine, total urinary arsenic, cesium, and tin were associated with increased odds of self-reported emphysema. Quantiles among 1-hydroxyphenanthrene, cadmium, manganese, lead, antimony, thallium, and tungsten were associated with an inverse relationship with self-reported emphysema in non-smokers.

CONCLUSION

The study determined that six types of urinary PAHs, cadmium, and cesium are positively associated with self-reported emphysema. Certain quantiles of 2-hydroxynaphthalene, arsenocholine, total urinary arsenic, cesium, and tin are positively associated with self-reported emphysema among non-smokers.

Respiratory Effects of Treatment with a Glucagon-Like Peptide-1 Receptor Agonist in Patients Suffering from Obesity and Chronic Obstructive Pulmonary Disease

Purpose

Chronic obstructive pulmonary disease (COPD) affects millions of people worldwide. Obesity is commonly seen concomitantly with COPD. People with COPD have reduced quality of life, reduced physical activity, chronic respiratory symptoms, and may suffer from frequent clinical exacerbations. Liraglutide is a glucagon-like peptide-1 receptor agonist (GLP-1RA) approved for weight loss and treatment of type-2 diabetes mellitus. In addition, liraglutide exerts anti-inflammatory actions by reducing IL-6 and MCP-1 levels. We investigated the effect of liraglutide on pulmonary function in people suffering from obesity and COPD.

Patients and Methods

In this controlled, double-blind trial, 40 people with obesity and COPD from two outpatient clinics were allocated randomly to receive liraglutide (3.0 mg, s.c.) or placebo (s.c.) for 40 weeks. At baseline and after 4, 20, 40, and 44 weeks, participants underwent pulmonary-function tests, 6-min walking test, and replied to a questionnaire regarding the clinical impact of COPD (COPD assessment test (CAT)-score).

Results

Compared with placebo, liraglutide use resulted in significant weight loss, increased forced vital capacity (FVC) and carbon monoxide diffusion capacity, and improved CAT-score. We found no significant changes in forced expiratory volume in one second (FEV₁), FEV₁/FVC, or 6-min walking distance.

Conclusion

In patients suffering from obesity and COPD, 40 weeks of treatment with liraglutide improved some measures of pulmonary function. Our study suggests that liraglutide at 3.0 mg may be appropriate treatment in patients with obesity and COPD.

The impact of hydration status and fluid distribution on pulmonary function in COPD patients

Chronic Obstructive Pulmonary Disease (COPD) patients have alterations in body composition. Bioelectrical impedance analysis (BIA) evaluates body composition, hydration status, and fluid distribution. Subjects with fluid disturbances have been found to have lower FEV1, respiratory muscle strength, and poor prognosis. We aimed to evaluate the effect of hydration status and fluid distribution on pulmonary function in COPD patients. A cross-sectional study, 180 patients with a confirmed diagnosis of COPD were included. Patients with asthma, advanced renal or liver disease, acute HF, exacerbation of COPD, or pacemakers were excluded. Hydration status variables (TBW, ECW, ICW) and disturbance of fluid distribution [impedance ratio (IR) > 0.84 and phase angle (PhA)] were evaluated by BIA. Pulmonary function was assessed by spirometry. The mean population age was 71.55 ± 8.94 years; 55% were men. Subjects were divided into two groups according to the IR ≥ 0.84 or < 0.84. The group with higher IR ≥ 0.84 had lower FEV1, FVC, FEV1/FVC, DLCO and, PhA compared to those with IR < 0.84. After adjusting for confounding variables TBW, ECW, IR ≥ 0.84, PhA, and resistance/height increase were associated with decreased FEV1. In the same way, with IR ≥ 0.84, edema index ≥ 0.48, trunk and abdominal IR were negatively associated with FVC, and PhA had a positive association with FVC. Fluid distribution, especially IR and PhA, could be a useful parameter for predicting pulmonary function in COPD patients.

Nicotine promotes chronic obstructive pulmonary disease via inducing pyroptosis activation in bronchial epithelial cells

Nicotine is one of the primary components in cigarettes, which is responsible for addiction. Numerous studies have investigated the effects of nicotine on pulmonary disease. The health of epithelial cells is important in the development of chronic obstructive pulmonary disease (COPD). Accumulating evidence has suggested that epithelial cell death may initiate or contribute to the progression of a number of lung diseases via airway remodeling. Pyroptosis is a unique form of inflammatory cell death mediated by the activation of caspase‑1 and the NOD‑like receptor protein‑3 (NLRP3) inflammasome. The present study aimed to evaluate whether pyroptosis of epithelial cells was involved in the progression of COPD. The normal human bronchial epithelial cell line 16HBE was treated with 0.1 or 1 µM nicotine. Then the proliferation ability of 16HBE cells was detected by CCK‑8. Cell death was detected by flow cytometry analysis and TUNEL assay. Subsequently, the levels of pro‑caspase 1, caspase 1, IL‑1β, IL‑18, NLRP3, ASC and cleaved GSDMD were examined by western blotting. It was revealed that nicotine treatment significantly induced cell death and suppressed proliferation of 16HBE cells. Furthermore, nicotine exposure increased the expression levels of caspase‑1, IL‑1β, IL‑18, NLRP3, apoptosis‑associated speck‑like protein and gasdermin D in 16HBE cells. Therefore, the present study concluded that nicotine treatment induced pyroptosis in 16HBE cells, which may be associated with the progression of COPD.

COVID-19 Pandemic: What Considerations Should Be Taken during the Assessment and Management of COPD Exacerbation?

The on-going coronavirus disease 2019 (COVID-19) pandemic could contribute to higher mortality in population with underlying respiratory diseases, including chronic obstructive pulmonary disease (COPD). The aim of this review was to inform readers pertaining to the correlation of COPD exacerbation and severe acute respiratory syndrome-2 (SARS-CoV-2) infection along with considerations that could be taken in the clinical diagnosis and management. The literature search was conducted on Google Scholar, Scopus, and PubMed databases using related terms (such as, but not limited to, “COVID-19,” “SARS-CoV-2,” “COPD management,” “N-acetylcysteine,” and “corticosteroids”) on November 1–9, 2021. Recent studies suggest that COVID-19 and COPD are correlated through three pathways, namely, angiotensin-converting enzyme 2 expression, dysregulation of biological parameters, and occurrence of pneumonia. Early detection of COVID-19 in patients with underlying COPD is difficult because they share similar symptoms, attributed to advanced progression of the infection and subsequently deteriorates lung function. During COPD management, clinicians are expected to take consideration on the effect of systemic corticosteroids if patients develop COVID-19. In conclusion, COVID-19 and COPD and its management are potentially correlated, contributing to the worsening of the disease. There is a need of immediate research to reveal the true correlation between COVID-19 and COPD to improve the management.

Regulation of lung epithelial cell senescence in smoking-induced COPD/emphysema by microR-125a-5p via Sp1 mediation of SIRT1/HIF-1a

Chronic obstructive pulmonary disease (COPD) affects the health of more than 300 million people worldwide; at present, there is no effective drug to treat COPD. Smoking is the most important risk factor, but the molecular mechanism by which smoking causes the disease is unclear. The senescence of lung epithelial cells is related to development of COPD. Regulation of miRNAs is the main epigenetic mechanism related to aging. β-Galactose staining showed that the lung tissues of smokers have a higher degree of cellular senescence, and the expression of miR-125a-5p is high. This effect is obvious for smokers with COPD/emphysema, and there is a negative correlation between miR-125a-5p levels and values for forced expiratory volume in one second (FEV1)/forced vital capacity (FVC). After Balb/c mice were chronically exposed to various concentrations of cigarette smoke (CS), plethysmography showed that lung function was impaired, lung tissue senescence was increased, and the senescence-associated secretory phenotype (SASP) in bronchoalveolar lavage fluid was increased. For mouse lung epithelial (MLE)-12 cells treated with cigarette smoke extract (CSE), Sp1 and SIRT1 levels were low, HIF-1α acetylation levels were high, and cell senescence and secretion of SASP factors were elevated. Down-regulation of miR-125a-5p or up-regulation of Sp1 reversed these effects. In addition, compared with mice exposed to CS, knockdown of miR-125a-5p reduced lung epithelial cell senescence and COPD/emphysema. Therefore, in smoking-induced COPD, elevated miR-125a-5p participates in the senescence of lung epithelial cells through Sp1/SIRT1/HIF-1α. These findings provide evidence related to the pathogenesis of COPD/emphysema caused by chronic smoking.

Evaluation of Diaphragm Thickness and Stiffness Using Ultrasound and Shear-Wave Elastography

ABSTRACT

The purposes of this study are to measure the thickness and stiffness of diaphragm in association with the respiratory cyclus and to assess the reproducibility of these measurements. Forty individuals who are volunteered for participating diaphragm evaluation were included in the study. Two radiologists with 14 and 15 years of experiences in abdominal ultrasound performed all examinations independently. Furthermore, 8 chronic obstructive pulmonary disease (COPD) patients were examined by only the first radiologist. Gray scale and shear-wave elastography imaging of only the right hemidiaphragm of all participants were performed. Thickness and stiffness of diaphragm were measured at the peak inspiration and end expiration phases. Intraclass correlation coefficients test was used to assess the interobserver agreement. The thickness and stiffness of diaphragm significantly increased with inspiration (P < 0.001). The mean ± SD stiffness of diaphragm in peak inspiration and end expiration phases was 51.84 ± 16.83 kPa and 38.49 ± 9.42 kPa, respectively, for the first radiologist and 49.61 ± 13.83 kPa and 37.52 ± 10.71 kPa, respectively, for the second radiologist. Intraclass correlation coefficient values for diaphragm stiffness were 0.667 and 0.736 in peak inspiration and end expiration phases, respectively. In COPD patients, there was no significant difference between stiffness measurements of respiratory phases. In conclusion, the current study revealed that diaphragm thickness and stiffness increase at inspiration, and these measurements are slightly more reproducible at the end of expiration. However, diaphragm stiffness changes between respiratory phases may not be valid for COPD patients, and this may be related to loss of force-generating capacity of diaphragm in COPD patients.

The role of long-acting muscarinic antagonist/long-acting β agonist fixed-dose combination treatment for chronic obstructive pulmonary disease in China: a narrative review

Objective

To provide an overview of the existing international and Chinese evidence regarding dual bronchodilator inhalation therapy and to make recommendations for the further improvement of chronic obstructive pulmonary disease (COPD) management in clinical practice in China.

Background

COPD is a progressive lung disease that is characterized by persistent airflow limitation and is a major contributor to the disease burden in China. Symptoms in Chinese patients are relatively more severe. Currently, many Chinese COPD patients are undertreated. Dual bronchodilator therapy consisting of a long-acting muscarinic antagonist (LAMA) and a long-acting β agonist (LABA) is considered a good choice for COPD patients due to the increased bronchodilation without an increase in adverse events; these combinations can fill in the gap in currently available COPD treatments and provide new pharmacotherapy options for Chinese patients. LAMA/LABA fixed-dose combinations (FDCs) have become more important in clinical practice and guidelines in China regarding their therapeutic effects and safety.

Methods

Clinical trials on LAMA/LABA in COPD were retrieved in ClinicalTrials.gov, while important COPD guidelines published in English or Chinese were found in PubMed and Wanfang Database.

Conclusions

We recommend the adoption of a clinical pathway in China that includes an assessment and management algorithm that considers the clinical characteristics in China and classifies the phenotypic characteristics of COPD according to a suitable system. Based on the current information, we can conclude that LAMA/LABA FDCs are a suitable and economically viable choice to reduce symptoms and improve the quality of life (QoL) of patients.

Mediterranean Diet and Fatty Liver Risk in a Population of Overweight Older Italians: A Propensity Score-Matched Case-Cohort Study

Hepatic steatosis, often known as fatty liver, is the most common hepatic disease in Western countries. The latest guidelines for the treatment of nonalcoholic fatty liver disease emphasize lifestyle measures, such as changing unhealthy eating patterns. Using a propensity score-matching approach, this study investigated the effect of adhering to a Mediterranean diet (MedDiet) on fatty liver risk in an older population (≥65 years) from Southern Italy. We recruited 1.403 subjects (53.6% men, ≥65 years) who completed a food frequency questionnaire (FFQ) and underwent clinical assessment between 2015 and 2018. For the assessment of the liver fat content, we applied the Fatty Liver Index (FLI). To evaluate the treatment effect of the MedDiet, propensity score matching was performed on patients with and without FLI > 60. After propensity score-matching with the MedDiet pattern as treatment, we found a higher consumption of red meat (p = 0.04) and wine (p = 0.04) in subjects with FLI > 60. Based on the FLI, the inverse association shown between adherence to the MedDiet and the risk of hepatic steatosis shows that the MedDiet can help to prevent hepatic steatosis. Consuming less red and processed meat, as well as alcoholic beverages, may be part of these healthy lifestyle recommendations.

Optimization and Application of an Efficient and Stable Inhalation Exposure System for Rodents

Inhalation is a promising and challenging method in pharmaceutical and biological science research. A stable environment is critical in dynamic inhalation administration. However, the establishment of a stable inhalation system is very challenging. Indacaterol glycopyrronium bromide inhalation powder (IM/GP mixed powder) is composed of indacaterol maleate and glycopyrronium bromide powder to treat chronic obstructive pulmonary disease (COPD). The aim of this study is to build suitable inhalation conditions and then to evaluate the pulmonary safety of this drug in Sprague-Dawley(SD) rats. In the research, through the coordination of the atomization flow, air pump flow, and scraper speed, aerosols were stabilized at 200 ± 20% mg/m³, and then rats were nose-only administered with the IM/GP mixed powder, Ultibro, and lactose-magnesium stearate mixed powder at 2.6 mg/kg/day for 14 days and 14 days of recovery period, respectively. After exposure, hematology, inflammatory cytokines in rats bronchoalveolar lavage fluid (BALF) and serum, histopathological examination were performed. Results showed that the stability of powder aerosols can be realized under the atomization generation flow: 10 L/min, sampling flow: 2 L/min, system pumping capacity: 10 L/min and powder scraper speed: 8-10 L/min, and there were no significant adverse effects on body weight, clinic signs, hematology, and pathology in rats. Overall, the results suggested that the IM/GP mixed powder inhalation at the dose of 2.6 mg/kg/d can be reached when the aerosol concentration is within the range of 200 ± 20% mg/m³, and there were no pulmonary toxicity effects in rats.

MIR-548ar-3p increases cigarette smoke extractinduced chronic obstructive pulmonary disease (COPD) injury through solute carrier family 17 member 9 (SLC17A9)

This study investigated the effect of microRNA mir-548ar-3p on cigarette smoke extract (CSE)-induced chronic obstructive pulmonary disease (COPD). High-throughput sequencing was performed on peripheral blood from smoking COPD patients and non-smoking individuals with normal pulmonary function, and mir-548ar-3p RNA, possessing large differential expression was selected. Experimental groups were divided into control, experimental model (EM), EM+mimic miRNA, negative control (NC) and EM+miR-548ar-3p groups; an empty vector or miR-548ar-3p mimic was transfected into human bronchial epithelial (HBE) cells. A COPD model was established by treating HBE cells with CSE. Cell viability, apoptosis and solute carrier family 17 member 9 (SLC17A9) protein expression were examined by cell counting kit-8, flow cytometry and Western blotting, respectively. Cell viability in the EM+miR-548ar-3p group decreased significantly, and the apoptosis rate and SLC17A9 protein expression increased significantly compared with the control (P<0.05, all groups). In smoking COPD patients, interferon (IFN)-? and interleukin (IL)-17? expression detected by ELISA was significantly higher than in normal individuals. miR-548ar-3p expression was significantly lower (P<0.05, all groups). These findings suggest that miR-548ar-3p was expressed at a lower level in COPD patients. miR-548ar-3p may increase the extent of CSE-induced COPD injury through SLC17A9.

NT-pro BNP in AECOPD-PH: old biomarker, new insights-based on a large retrospective case-controlled study

BACKGROUND

Pulmonary hypertension (PH) is one of the common complications in chronic obstructive pulmonary disease (COPD). The study aimed to evaluate the predicting ability of N-terminal pro brain natriuretic peptide (NT-pro BNP) in patients with AECOPD-PH and its relationship with the severity of PH.

METHODS

A large retrospective case-controlled study (n = 1072) was performed in the First Affiliated Hospital of Xinjiang Medical University from January 2018 to December 2020, and patients were divided into stable COPD (n = 178), AECOPD (n = 688) and AECOPD-PH group (n = 206). Different statistical models were used to screen for reliable and stable biomarkers.

RESULTS

In unadjusted analysis and PSM (model 1, 2, 3), red cell distribution width (RDW), total bilirubin (TBIL), and NT-pro BNP were higher in patients with AECOPD-PH than those in AECOPD group. Logistic regression analysis showed, when the range of NT-proBNP was 271-1165 pg/mL (OR: 0.293; 95%CI: 0.184-0.467; P < 0.001) and NT-proBNP > 1165 pg/mL (OR: 0.559; 95%CI: 0.338-0.926; P = 0.024), the morbidity risk of PH in AECOPD patients was increased, so did TBIL. In receiver operating characteristic (ROC) curves, at the cut-off value of NT-proBNP was 175.14 pg/mL, AUC was 0.651 (P < 0.001), which was better than TBIL (AUC: 0.590, P < 0.001). As for the results of rank correlation analysis, NT-proBNP had a weak correlation with severity of PH with AECOPD (rs = 0.299, P = 0.001) and its relative relevance with other biomarkers (RDW was 0.359 and TBIL was 0.238, P < 0.001).

CONCLUSIONS

Our findings suggest that NT-proBNP has a diagnostic efficacy in AECOPD-PH and NT-proBNP has a weak correlation with severity of PH with AECOPD.

Chronic Obstructive Pulmonary Disease is a Risk Factor for Sensorineural Hearing Loss: A US Population Study

OBJECTIVES

The goal of this study is to determine if chronic obstructive pulmonary disease (COPD) is associated with sensorineural hearing loss (SNHL) in a national database.

STUDY DESIGN

Cross-sectional study.

SETTING

National sample of the United States population.

PATIENTS

Adults with audiometric and spirometry data from the National Health and Nutrition Examination Study (NHANES) database.

INTERVENTIONS

None.

METHODS

A total of 2,464 adults with spirometry and audiometry data from the NHANES database (2009-2012) were studied. Outcome measures included hearing, measured by high-frequency pure tone average (HFPTA; 3, 4, 6, 8 kHz) and low-frequency pure tone average (LFPTA; .5, 1, 2 kHz) frequencies. SNHL was defined as a HFPTA or LFPTA threshold more than 25 decibels (dB) in the better ear. Multivariable regression analyses explored the association between hearing loss and COPD.

RESULTS

The prevalence of COPD was 19.8% in individuals with SNHL in the better ear and 4.7% in individuals with normal hearing (p < 0.001). Presence of COPD was associated with elevated hearing thresholds (worse hearing) at each individual frequency. The presence of COPD was independently associated with a 3.29 dB (95% CI: 1.48, 5.09) increase in HFPTA (p < 0.001), and 2.32 dB (1.13, 3.50) increase in LFPTA (p < 0.001) after controlling for medical, social, and environmental covariates. The presence of COPD was independently associated with a 1.85-fold (1.12, 3.06) increased odds of isolated low-frequency SNHL (p = 0.017).

CONCLUSIONS

COPD was independently associated with sensorineural hearing loss after controlling for multiple confounding factors. These results contribute to the evidence that COPD and pulmonary dysfunction can be comorbid with hearing decline.

Ultrasound Shear Wave Elastography for Evaluation of Diaphragm Stiffness in Patients with Stable COPD: A Pilot Trial

OBJECTIVES

Skeletal muscle dysfunction is one of the most common comorbidities in chronic obstructive pulmonary disease (COPD). The occurrence of respiratory failure in COPD is common and leads to the patient's death. The diaphragm is the most important muscle in the respiratory system and plays a key role in the onset of respiratory failure. This study explores the feasibility of ultrasound shear wave elastography (SWE) to measure diaphragmatic stiffness and evaluates its changes in COPD patients.

METHODS

In total, 77 participants (43 patients with stable COPD and 34 healthy controls) were enrolled. All subjects underwent complete diaphragmatic ultrasound SWE measurements and pulmonary function tests. The diaphragmatic stiffness was indicated via diaphragmatic shear wave velocity (SWV) at functional residual capacity (FRC). A trained operator performed the ultrasound SWE examinations of the first 15 healthy controls thrice to assess the reliability of diaphragmatic SWE.

RESULTS

A good to excellent reliability was found in diaphragmatic SWV at FRC (ICC = 0.93, 95%CI 0.82-0.98). As compared to the control group, the diaphragmatic SWV at FRC was considerably high in the COPD group (median 2.5 m/s versus 2.1 m/s, P = .008). Diaphragmatic SWV at FRC was linked to forced expiratory volume in one second (r = -0.30, P = .009), forced vital capacity (r = -0.33, P = .003), modified Medical Research Council score (r = 0.30, P = .001), and COPD assessment test score (r = 0.48, P < .001).

CONCLUSIONS

Ultrasound SWE may be employed as an effective tool for quantitative evaluation of diaphragm stiffness and can help in personalized management of COPD, such as treatment guidance and follow-up monitoring.

Evaluation of the cross-sectional area of small pulmonary vessels in the diagnosis of chronic obstructive pulmonary disease by quantitative computed tomography: A case-control study

Patients with chronic obstructive pulmonary disease (COPD) have a reduced cross-sectional area (CSA) of small pulmonary vessels and decreased pulmonary function test (PFT) indexes. This study investigated the value of small pulmonary vessel CSA in diagnosing and evaluating the severity of COPD and its correlation with PFT.This retrospective case-control study included patients with COPD who underwent multi-slice spiral computed tomography (CT) between March 2015 and December 2018. COPD severity was graded. Patients with normal CT results were included as controls. The CSA of small pulmonary vessels at the sub-segmental (5-10 mm2) and sub-sub-segmental (<5 mm2) levels was measured. Receiver operating characteristic (ROC) curves were used to evaluate the effect of CSA for COPD risk prediction. The correlation between CSA% and PFT indexes was evaluated.There were 124 and 106 patients in the COPD and control groups, respectively. The %CSA <5 and %CSA5-10 were smaller in the COPD group than in controls (P  < .05). The %CSA <5 in each subgroup stratified by COPD severity was smaller than in controls (P  < .05). The % CSA5-10 was significantly smaller in the moderate and severe groups than in controls (P  < .05). At 0.655%CSA <5 cut-off, the ROC area under the curve (AUC) was 0.765. For %CSA5-10, a 0.565 cut-off led to an AUC of 0.752. Both %CSA <5 and %CSA5-10 were positively correlated with all PFT indexes (r = 0.180-0.462, all P  < .05).CSA was positively correlated with PFT. Analysis of small pulmonary vessel CSA based on CT images contributes to diagnosing and assessing the severity of COPD.

Clinical Utility of the Electrocardiographic P-Wave Axis in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND

The vertical P-wave axis on electrocardiography (ECG) is a useful criterion for screening patients with chronic obstructive pulmonary disease (COPD). This study aimed to investigate the clinical characteristics of patients with COPD with a vertical P-wave axis as they have not yet been elucidated.

METHODS

Keio University and its affiliated hospitals conducted an observational COPD cohort study over 3 years. We analyzed 201 patients using ECG and chest computed tomography.

RESULTS

The severity of airflow limitation was higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. Patients with a P-wave axis >75° exhibited significantly higher total COPD assessment test scores and increased St. George's Respiratory Questionnaire total, activity, and impact scores than those with a P-wave axis ≤75°. The incidence of exacerbations over 1 and 3 years was significantly higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. The optimal cutoff for the P-wave axis for a percentage of the predicted forced expiratory volume in 1 s <50% and future exacerbations over 3 years was 70° (the areas under the curve [AUC]: 0.788; sensitivity: 65.3%; specificity: 78.3%) and 79° (AUC: 0.642; sensitivity: 36.7%; specificity: 92.6%). The ratio of the low attenuation area was also significantly higher in patients with a P-wave axis >75° than in those with a P-wave axis ≤75°. However, the ratio of the airway wall area did not differ between the 2 groups.

CONCLUSIONS

Patients with COPD with a vertical P-wave axis exhibited severe airflow limitation and emphysema, a worse health status, and more frequent exacerbation than patients without a vertical P-wave. Detection of the vertical P-wave axis by ECG is beneficial for the management of patients with COPD.

Inspiratory muscle activation during inspiratory muscle training in patients with COPD

BACKGROUND AND OBJECTIVES

The main target of inspiratory muscle training (IMT) is to improve diaphragm function in patients with COPD who have inspiratory muscle weakness. Ventilatory demand is already increased during quiet breathing in patients with COPD, and whether threshold load imposed by IMT would active more accessory muscle remained to be determined. The purpose of this study was to examine diaphragm and sternocleidomastoid (SCM) activation during IMT with intensities of 30% and 50% maximal inspiratory pressure (P_Imax).

METHODS

Patients with COPD and a P_Imax lower than 60 cmH₂O were recruited for the study. Surface electromyography (EMG) was used to measure diaphragm and SCM activation, and group-based trajectory modeling (GBTM) was used to identify activation patterns during IMT. The generalized estimating equation (GEE) was then used to detect differences of variables between various breathing tasks. Statistical significance was established at p < 0.05.

RESULTS

A total of 30 patients with COPD participated in this study. All patients demonstrated significant increases in diaphragm and SCM activation during 30% and 50% P_Imax of IMT than during quiet breathing (all p < 0.001). Diaphragm demonstrated two distinct patterns in response to IMT: low activation (n = 8) and high activation (n = 22) group using GBTM analysis.

CONCLUSION

Diaphragm and SCM were substantially activated during IMT in patients with COPD who had inspiratory muscle weakness. Regardless of whether diaphragm activation was high or low, SCM was activated to a greater extent in response to IMT.

Immune Characteristics Analysis and Transcriptional Regulation Prediction Based on Gene Signatures of Chronic Obstructive Pulmonary Disease

Purpose

The variation in inflammation in chronic obstructive pulmonary disease (COPD) between individuals is genetically determined. This study aimed to identify gene signatures of COPD through bioinformatics analysis based on multiple gene sets and explore their immune characteristics and transcriptional regulation mechanisms.

Methods

Data from four microarrays were downloaded from the Gene Expression Omnibus database to screen differentially expressed genes (DEGs) between COPD patients and controls. Weighted gene co-expression network analysis was applied to identify trait-related modules and then select key module-related DEGs. The optimized gene set of signatures was obtained using the least absolute shrinkage and selection operator (LASSO) regression analysis. The CIBERSORT algorithm and Pearson correlation test were used to analyze the relationship between gene signatures and immune cells. Finally, public databases were used to predict the transcription factors (TFs) and upstream miRNAs.

Results

A total of 127 DEGs in COPD were identified from the combined dataset. By considering the intersection of DEGs and genes in two trait-related modules, 83 key module-related DEGs were identified, which were mainly enriched in interleukin-related pathways. Seven-gene signatures, including MTHFD2, KANK3, GFPT2, PHLDA1, HS3ST2, FGG, and RPS4Y1, were further selected using the LASSO algorithm. These gene signatures showed the predictive potential for COPD risks and were significantly correlated with 18 types of immune cells. Finally, nine miRNAs and three TFs were predicted to target MTHFD2, GFPT2, PHLDA1, and FGG.

Conclusion

We proposed the seven-gene-signature to predict COPD risk and explored its potential immune characteristics and regulatory mechanisms.

Potential for integrating yoga within pulmonary rehabilitation and recommendations of reporting framework

There is a rising burden of chronic obstructive pulmonary disease (COPD) in India. Pulmonary rehabilitation (PR), is a universally recommended multidisciplinary therapeutic strategy for the management of COPD; however, its needs are unmet. The diversity in the healthcare systems, availability of PR specialists and sociocultural multiformity requires contextualised and innovative PR models. Culturally sensitive elements, such as yoga, have some evidence of a positive impact in the management of COPD. Yoga and PR are based on similar principles with a holistic approach of involving physical activities, behaviour change techniques and psychological support to improve disease outcomes. Arguably the principles of PR and yoga are complementary but there are some important differences in the intensities of activities, exercise types and inclusion of mindfulness in components that must be considered. Components of PR enable aerobic capacity building, strengthening of muscles of the upper and lower extremities and building awareness towards disease management. Yoga, on the other hand, primarily can focus on core strengthening, breathing control, mindfulness and self-awareness. We discuss the potential of integrating the sociocultural appeal of yoga with PR delivered at international standards, and how an integrated approach may lead to optimal referral, uptake and completion.

Pretreatment Lung Function and Checkpoint Inhibitor Pneumonitis in NSCLC

Introduction

Checkpoint inhibitor pneumonitis (CIP) is a serious toxicity of anti-programmed death-(ligand) 1 immunotherapy. Whether pretreatment differences in pulmonary function exist in patients who develop CIP is unknown. We analyzed the pulmonary function tests (PFTs) of patients with NSCLC treated with immune checkpoint inhibitors (ICIs) to evaluate whether pretreatment lung function was associated with CIP development.

Methods

Patients were included if they completed greater than or equal to 1 PFT within 2 years preceding ICI initiation. CIP status (CIP+: developed CIP, CIP-: did not develop CIP) was determined clinically. Generalized estimating equation-based linear regression was used to evaluate the effects of time and CIP on lung function. Primary outcomes included the following: percent-predicted forced expiratory volume in 1 second (FEV1pp), percent-predicted forced vital capacity (FVCpp), and FEV1/FVC.

Results

A total of 43 patients (34 CIP-, 9 CIP+) with 79 PFTs (59 CIP-, 20 CIP+) were included. CIP+ patients had a 21.7% lower pretreatment FEV1pp compared with the CIP- group (95% confidence interval: -38.6 to -4.7). No statistically significant differences in FVCpp or FEV1/FVC were observed. The prevalence of obstructive lung disease was similar in both groups at 67% and 62% for the CIP+ and CIP- cohorts, as was the prevalence of current/former smoking at 100% and 93%, respectively.

Conclusions

Pretherapy differences in lung function were evident between patients who did and did not develop CIP, though the prevalence of obstructive lung disease was similar. Prospective studies are needed to validate these findings, inform potential risk factors for CIP, and investigate the effects of ICI treatment and CIP on pulmonary function in patients with NSCLC.

Burden of Comorbidities in Patients with OSAS and COPD-OSAS Overlap Syndrome

Background and Objectives: Obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD) are usually associated with multi-morbidity. The aim of this study was to retrospectively investigate the prevalence of comorbidities in a cohort of patients with OSAS and COPD-OSAS overlap syndrome (OS) patients and to explore differences between these two groups. Materials and Methods: Included were consecutive OS patients and OSAS patients who had been referred to our sleep laboratory, and were matched in terms of sex, age, BMI, and smoking history. Presence of comorbidities was recorded based on their medical history and after clinical and laboratory examination. Results: The two groups, OS patients (n = 163, AHI > 5/h and FEV₁/FVC < 0.7) and OSAS patients (n = 163, AHI > 5/h, and FEV₁/FVC > 0.7), did not differ in terms of apnea hypopnea index (p = 0.346), and oxygen desaturation index (p = 0.668). Compared to OSAS patients, OS patients had lower average SpO₂ (p = 0.008) and higher sleep time with oxygen saturation <90% (p = 0.002) during sleep, and lower PaO₂ (p < 0.001) and higher PaCO₂ (p = 0.04) in wakefulness. Arterial hypertension was the most prevalent comorbidity for both OS and OSAS, followed by dyslipidemia, cardiovascular disease (CVD) and diabetes. OS was characterized by a higher prevalence of total comorbidities (median (IQR):2 (1–3) vs. 2 (1–2), p = 0.033), which was due to the higher prevalence of CVD (p = 0.016) than OSAS. No differences were observed in other comorbidities. Conclusions: In OS patients, nocturnal hypoxia and impaired gas exchange in wakefulness are more overt, while a higher burden of CVD is observed among them in comparison to sex-, age- and BMI-matched OSAS patients.

Role of the Emphysema Index Combined with the Chronic Obstructive Pulmonary Disease Assessment Test Score in the Evaluation of Chronic Obstructive Pulmonary Disease

Background

This study aimed to evaluate the efficacy of the emphysema index (EI) in distinguishing chronic bronchitis (CB) from chronic obstructive pulmonary disease (COPD) and its role, combined with the COPD Assessment Test (CAT) score, in the evaluation of COPD.

Methods

A total of 92 patients with CB and 277 patients with COPD were enrolled in this study. Receiver operating characteristic (ROC) curves were analyzed to evaluate whether the EI can preliminarily distinguish chronic bronchitis from COPD. Considering the heterogeneity of COPD, there might be missed diagnosis of some patients with bronchitis type when differentiating COPD patients only by EI. Therefore, patients with COPD were classified according to the CAT score and EI into four groups: Group 1 (EI < 16%, CAT < 10), Group 2 (EI < 16%, CAT ≥ 10), Group 3 (EI ≥ 16%, CAT < 10), and Group 4 (EI ≥ 16%, CAT ≥ 10). The records of pulmonary function and quantitative computed tomography findings were retrospectively analyzed.

Results

ROC curve analysis showed that EI = 16.2% was the cutoff value for distinguishing COPD from CB. Groups 1 and 2 exhibited significantly higher maximal voluntary ventilation (MVV) percent predicted (pred), forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC), maximal midexpiratory flow of 25-75% pred, carbon monoxide-diffusing capacity (DLCO)/alveolar ventilation (VA), FEV1 % pred (p ≤ 0.013), and maximal expiratory flow 50% pred (all p < 0.05) than Group 4. FEV1/FVC and DLCO/VA were significantly lower in Group 3 than in Group 2 (p=0.002 and p < 0.001, respectively). The residual volume/total lung capacity was higher in Group 3 than in Groups 1 and 2 (p < 0.05).

Conclusions

The combination of EI and CAT was effective in the evaluation of COPD.

Cigarette Smoke Promotes Interleukin-8 Production in Alveolar Macrophages Through the Reactive Oxygen Species/Stromal Interaction Molecule 1/Ca2+ Axis

Chronic obstructive pulmonary disease (COPD), primarily attributed to cigarette smoke (CS), is characterized by multiple pathophysiological changes, including oxidative stress and inflammation. Stromal interaction molecule 1 (STIM1) is a Ca²⁺ sensor that regulates Ca²⁺ entry in different types of cells. The present study aimed to explore the relationship between CS-induced oxidative stress and inflammation, as well as the functional role of STIM1 thereinto. Our results showed that the reactive oxygen species (ROS)/STIM1/Ca²⁺ axis played a critical role in CS-induced secretion of interleukin (IL)-8 in human alveolar macrophages. Specifically, smokers with COPD (SC) showed higher levels of ROS in the lung tissues compared with healthy non-smokers (HN). STIM1 was upregulated in the lung tissues of COPD patients. The expression of STIM1 was positively associated with ROS levels and negatively correlated with pulmonary function. The expression of STIM1 was also increased in the bronchoalveolar lavage fluid (BALF) macrophages of COPD patients and PMA-differentiated THP-1 macrophages stimulated by cigarette smoke extract (CSE). Additionally, CSE-induced upregulation of STIM1 in PMA-differentiated THP-1 macrophages was inhibited by pretreatment with N-acetylcysteine (NAC), a ROS scavenger. Transfection with small interfering RNA (siRNA) targeting STIM1 and pretreatment with NAC alleviated CSE-induced increase in intracellular Ca²⁺ levels and IL-8 expression. Furthermore, pretreatment with SKF-96365 and 2-APB, the inhibitors of Ca²⁺ influx, suppressed CSE-induced secretion of IL-8. In conclusion, our study demonstrates that CSE-induced ROS production may increase the expression of STIM1 in macrophages, which further promotes the release of IL-8 by regulating Ca²⁺ entry. These data suggest that STIM1 may play a crucial role in CSE-induced ROS production and inflammation, and participate in the pathogenesis of COPD.