Burden of chronic obstructive pulmonary disease: healthcare costs and beyond

Chronic obstructive pulmonary disease's eosinophilic phenotype: Clinical characteristics, biomarkers and biotherapy

COPD is a chronic, heterogeneous inflammatory disorder of the airways with persistent and poorly reversible airflow limitation, causing symptoms such as cough, shortness of breath, and sputum production. Despite optimal treatment, some patients remain symptomatic due to the disease's heterogeneity, manifesting in various phenotypes. One notable phenotype involves eosinophilic inflammation, with a variable prevalence. Identifying eosinophilic phenotypes is crucial for tailored therapeutic strategies, as they respond favorably to corticosteroids and potentially biologics. Recent advances in both clinical trials and spontaneous research have helped understand the biological and clinical characteristics of this phenotype, although no universal consensus has been reached yet on the definition of the cut-off values of the eosinophil peripheral blood count. Moreover, there is evidence of novel emerging biomarkers which might go beyond the sole eosinophil count, while significant advancements in terms of pharmacological treatment have been made, with dupilumab being the first biological drug being licensed for COPD patients with elevated circulating eosinophils in the stable phase. In light of the above, although several papers have been written on the relationship between eosinophils and COPD, in the present work we endeavored to summarize and discuss the pivotal literature findings regarding the eosinophilic COPD in order to help define the biological and clinical features of this peculiar phenotype, with particular attention to the use of established and emerging biomarkers, as well as current and future therapeutic perspectives.

Inequalities in disease burden and care quality of chronic obstructive pulmonary disease, 1990-2021: Findings from the Global Burden of Disease Study 2021

Background

Chronic obstructive pulmonary disease (COPD) is one of the primary causes of significant morbidity and mortality worldwide. This study aimed to explore the cross-country inequalities by age, sex, and region in COPD's burden and care quality from 1990 to 2021.

Methods

We obtained data from the Global Burden of Disease 2021. Using age-standardised disability-adjusted life years rate (ASDR) per 100 000 population and quality of care index (QCI), we quantified the COPD burden and care quality, respectively. Applying the principal component analysis method, we calculated QCI scores, ranging from 0 to 100, where higher values indicate better care quality. We quantified temporal trends from 1990 to 2021 for ASDR and QCI by estimated annual percentage change (EAPC). Finally, we assessed the absolute and relative disparities in ASDR and QCI across countries using the slope index of inequality (SII) and concentration index.

Results

Between 1990 and 2021, there was a notable decline in ASDR of COPD globally (1990 = 1492.64; 2021 = 940.66; EAPC = -1.71), accompanied by an increase in QCI (1990 = 58.42; 2021 = 73.86; EAPC = 0.89). Regions with middle sociodemographic index (SDI) consistently demonstrated the highest ASDR and the lowest QCI in 1990 (ASDR = 2332.91; QCI = 31.70), whereas by 2021, low-middle SDI regions exhibited similar trends (ASDR = 1707.90; QCI = 57.50). In 2021, the highest ASDR was among individuals aged 95 years and above (16251.22), while the lowest QCI was among people aged 70-74 years (72.18). Papua New Guinea recorded the highest ASDR and the lowest QCI in 2021 (ASDR = 3004.36; QCI = 19.18). Compared to 1990, where the SII for ASDR was -612.44 and for QCI was 21.78, with concentration indices of -0.14 for ASDR and 0.11 for QCI, the absolute values of both SII and concentration index were smaller in 2021, with ASDR's SII at -555.90, QCI's at 16.72, ASDR's concentration index at -0.13, and QCI's at 0.04.

Conclusions

The global burden of COPD decreases and care quality increases over time, with notable variations across ages, sexes and SDI regions. Countries with lower SDI had disproportionately higher burden and poorer care quality for COPD.

Development and validation of a nomogram for predicting COPD: A nationwide population-based study in South Korea

Chronic obstructive pulmonary disease (COPD) remains a significant global health burden exacerbated by tobacco smoking, occupational exposure, and air pollution. COPD is one of the top 3 causes of death worldwide. In South Korea, the COPD burden is expected to increase due to ongoing exposure to risk factors and the aging population. COPD is extensively underdiagnosed or underestimated, owing to a lack of public awareness. This study aimed to develop and validate a nomogram for COPD by using national data to promote early diagnosis and intervention. This study drew on a dataset from the 7th Korea National Health and Nutrition Examination Survey from 2016 to 2018, including 10,819 subjects aged 40 years or older with spirometry results. Influence of demographic, socioeconomic, and health-related factors on the incidence. Multivariable logistic regression was used to identify the significant predictors of the nomogram. The nomogram was validated using receiver operating characteristic curves, calibration plots, and concordance index (C-index). Internal validation was performed by bootstrapping. In the final analysis, 1059 (14.0%) participants had COPD. Key risk factors associated with increased COPD risk included being male, aged 70 and older, lower educational level, living in a rural area, current smoking status, underweight, and history of tuberculosis and asthma. The area under the curve (AUC) of the model was 0.822 (95% CI: 0.810-0.832), indicating that the nomogram has a high ability to identify COPD. The nomogram demonstrated solid predictive performance, as confirmed by calibration plots with a C-index (of 0.822) for the validation set with 1000 bootstrap samples. In conclusion, we developed a tool for the early detection of COPD with good properties in primary care settings, without spirometry. Appropriate and early diagnosis of COPD can have a crucial impact on public health.

Prevalence and Associated Factors of Chronic Respiratory Symptoms among Street Sweepers in Bangkok, Thailand: A Cross-sectional Study

Background

Chronic respiratory diseases are becoming a more prominent cause of morbidity and mortality worldwide. Street sweepers are commonly found in low- and middle-income countries. This job involves outdoor work that exposes workers to various health hazards and air pollution, particularly affecting respiratory health. There is still limited research focusing specifically on street sweepers. The study aims to examine the prevalence of chronic respiratory symptoms and the associated factors in street sweepers in Bangkok, Thailand.

Materials and Methods

We undertook a cross-sectional survey between February and April 2023. A multi-stage sampling technique was employed, stratifying the sample according to district locations within Bangkok, Thailand. Data were collected through a questionnaire assessing demographic characteristics, occupational and environmental factors, and respiratory symptoms using a modified version of the Medical Research Council questionnaire. Data analysis included bivariate analysis and multiple logistic regression.

Results

The response rate was 98.0% (n = 341). The prevalence of chronic respiratory symptoms among street sweepers in Bangkok, Thailand, with at least one respiratory symptom was reported by 33.7% of the participants, specifically cough (22%), phlegm (20.2%), dyspnea (17.6%), and wheeze (7.0%). The average age of the sample group was 43.2 years, with a majority being female (85.9%). Among the participants, 88.3% were non-smokers, while 37.2% reported exposure to secondhand smoke. All participants reported the use of respiratory protective equipment, with face masks used at 78.9%. 7.3% of the participants lived near sources of pollution, and 12.0% were involved in household pollution activities. An average annual air quality index in the workplace area was categorized as 'good' at 57.8%. Multiple logistic regression analysis revealed significant associations of chronic respiratory symptoms with the following factors: exposure to secondhand smoke [odds ratio (OR) =2.3, 95% confidence interval (CI) 1.3-4.2] and household activities (OR = 3.0, 95% CI 1.3-6.6).

Conclusion

Exposure to secondhand smoke and indoor air pollutants in household environments are significant factors associated with the symptoms. Raising awareness about secondhand smoke hazards in household and environmental settings and promoting self-care practices related to various activities with potential exposure to indoor air pollution is crucial.

Inpatient Complication Rates of Bronchoscopic Lung Volume Reduction in the United States

BACKGROUND

Early randomized controlled trials (RCTs) of bronchoscopic lung volume reduction (BLVR) have shown clinically meaningful benefits in lung function, dyspnea, and quality of life in patients with severe emphysema. Safety outcome data obtained after BLVR in the United States are scarce outside the RCTs.

RESEARCH QUESTION

What is the rate of inpatient complications after BLVR in the real world in the United States?

STUDY DESIGN AND METHODS

We used The National Inpatient Sample database to identify in-hospital complications after BLVR from 2018 through 2020. Complications were defined as pneumothorax, COPD exacerbation, pneumonia, hemoptysis, acute respiratory failure, and valve removal. We also analyzed all-cause in-hospital mortality and length of stay (LOS).

RESULTS

We identified 467 admissions related to BLVR procedures. The number of procedures doubled between 2019 and 2020 (from 153 to 295 procedures). The median age was 67.9 years (interquartile range [IQR], 61.1-72.8 years), 210 patients (45.0%) were female, 401 patients (85.8%) were White, and Medicare was the primary expected payer for 72.8% of patients. Most procedures were performed in urban teaching hospitals (56.9%). The rate of pneumothorax was 26.3%, that of acute respiratory failure was 19.5%, that of COPD exacerbation was 8.8%, that of pneumonia was 7.3%, and that of hemoptysis was 5.3%. Chest tube placement was required in 84 of 123 patients (68.3%) with pneumothorax. The endobronchial valve had to be removed in 69 patients (14.8%). The median LOS was 2.8 days (IQR, 2.3-4.5 days). The number of in-hospital deaths was fewer than 11 (< 2.3%). Overall, the subgroup who experienced in-hospital complications did not differ significantly from the others in terms comorbidities, demographics, and hospital characteristics.

INTERPRETATION

The real-world complication rate after BLVR was similar to the published complication rates from early randomized clinical trials. In-hospital mortality was low, suggesting that aside from the commonly anticipated complications, BLVR is a safe treatment option for severe emphysema.

Regional Differences in American Indian/Alaska Native Chronic Respiratory Disease Disparity: Evidence from National Survey Results

American Indian/Alaska Native (AI/AN) persons in the US experience a disparity in chronic respiratory diseases compared to white persons. Using Behavioral Risk Factor Surveillance System (BRFSS) data, we previously showed that the AI/AN race/ethnicity variable was not associated with asthma and/or chronic obstructive pulmonary disease (COPD) in a BRFSS-defined subset of 11 states historically recognized as having a relatively high proportion of AI/AN residents. Here, we investigate the contributions of the AI/AN variable and other sociodemographic determinants to disease disparity in the remaining 39 US states and territories. Using BRFSS surveys from 2011 to 2019, we demonstrate that irrespective of race, the yearly adjusted prevalence for asthma and/or COPD was higher in the 39-state region than in the 11-state region. Logistic regression analysis revealed that the AI/AN race/ethnicity variable was positively associated with disease in the 39-state region after adjusting for sociodemographic covariates, unlike in the 11-state region. This shows that the distribution of disease prevalence and disparity for asthma and/or COPD is non-uniform in the US. Although AI/AN populations experience this disease disparity throughout the US, the AI/AN variable was only observed to contribute to this disparity in the 39-state region. It may be important to consider the geographical distribution of respiratory health determinants and factors uniquely impactful for AI/AN disease disparity when formulating disparity elimination policies.

Exploring Molecular Mechanisms and Biomarkers in COPD: An Overview of Current Advancements and Perspectives

Chronic obstructive pulmonary disease (COPD) plays a significant role in global morbidity and mortality rates, typified by progressive airflow restriction and lingering respiratory symptoms. Recent explorations in molecular biology have illuminated the complex mechanisms underpinning COPD pathogenesis, providing critical insights into disease progression, exacerbations, and potential therapeutic interventions. This review delivers a thorough examination of the latest progress in molecular research related to COPD, involving fundamental molecular pathways, biomarkers, therapeutic targets, and cutting-edge technologies. Key areas of focus include the roles of inflammation, oxidative stress, and protease-antiprotease imbalances, alongside genetic and epigenetic factors contributing to COPD susceptibility and heterogeneity. Additionally, advancements in omics technologies-such as genomics, transcriptomics, proteomics, and metabolomics-offer new avenues for comprehensive molecular profiling, aiding in the discovery of novel biomarkers and therapeutic targets. Comprehending the molecular foundation of COPD carries substantial potential for the creation of tailored treatment strategies and the enhancement of patient outcomes. By integrating molecular insights into clinical practice, there is a promising pathway towards personalized medicine approaches that can improve the diagnosis, treatment, and overall management of COPD, ultimately reducing its global burden.

Gut virome alterations in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is one of the primary causes of mortality and morbidity worldwide. The gut microbiome, particularly the bacteriome, has been demonstrated to contribute to the progression of COPD. However, the influence of gut virome on the pathogenesis of COPD is rarely studied. Recent advances in viral metagenomics have enabled the rapid discovery of its remarkable role in COPD. In this study, deep metagenomics sequencing of fecal virus-like particles and bacterial 16S rRNA sequencing was performed on 92 subjects from China to characterize alterations of the gut virome in COPD. Lower richness and diversity of the gut virome were observed in the COPD subjects compared with the healthy individuals. Sixty-four viral species, including Clostridium phage, Myoviridae sp., and Synechococcus phage, showed positive relationships with pulmonary ventilation functions and had markedly declined population in COPD subjects. Multiple viral functions, mainly involved in bacterial susceptibility and the interaction between bacteriophages and bacterial hosts, were significantly declined in COPD. In addition, COPD was characterized by weakened viral-bacterial interactions compared with those in the healthy cohort. The gut virome showed diagnostic performance with an area under the curve (AUC) of 88.7%, which indicates the potential diagnostic value of the gut virome for COPD. These results suggest that gut virome may play an important role in the development of COPD. The information can provide a reference for the future investigation of diagnosis, treatment, and in-depth mechanism research of COPD.

IMPORTANCE

Previous studies showed that the bacteriome plays an important role in the progression of chronic obstructive pulmonary disease (COPD). However, little is known about the involvement of the gut virome in COPD. Our study explored the disease-specific virome signatures of patients with COPD. We found the diversity and compositions altered of the gut virome in COPD subjects compared with healthy individuals, especially those viral species positively correlated with pulmonary ventilation functions. Additionally, the declined bacterial susceptibility, the interaction between bacteriophages and bacterial hosts, and the weakened viral-bacterial interactions in COPD were observed. The findings also suggested the potential diagnostic value of the gut virome for COPD. The results highlight the significance of gut virome in COPD. The novel strategies for gut virome rectifications may help to restore the balance of gut microecology and represent promising therapeutics for COPD.

Dyspnea and Quality of Life Improvements with Management of Comorbid Obstructive Sleep Apnea in Chronic Lung Disease

Obstructive sleep apnea (OSA) has emerged as a significant and prevalent comorbidity associated with chronic lung diseases, including chronic obstructive pulmonary disease, asthma, and interstitial lung diseases. These overlap syndromes are associated with worse patient-reported outcomes (sleep quality, quality of life measures, mental health) than each condition independently. Observational studies suggest that patients with overlap syndrome who are adherent to positive airway pressure therapy report improved quality of life, sleep quality, depression, and daytime symptoms. Screening for and management of OSA in patients with overlap syndrome should emphasize the interconnected nature of these 2 conditions and the positive impact that OSA management can have on patients' well-being and overall health.

Blood eosinophils levels in a Colombian cohort of biomass-and tobacco-related COPD patients

Introduction

Chronic obstructive pulmonary disease (COPD) is a major cause of illness and death among adults. In 2019, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy incorporated blood eosinophils as a biomarker to identify patients at increased risk of exacerbations which, with the history of exacerbations during the previous year, allows identification of patients who would benefit from anti-inflammatory treatment to reduce the risk of future exacerbations. The aim of this study was to describe demographic and clinical characteristics, eosinophil counts, and exacerbations in a cohort of COPD patients stratified by clinical phenotypes (non-exacerbator, frequent exacerbator, asthma-COPD overlap) in a Colombian cohort at 2600 meters above sea level.

Methods

A descriptive analysis of a historical cohort of patients with a confirmed diagnosis of moderate to severe COPD (FEV1/FVC < 0.7 and at least one risk factor for COPD) from two specialized centers with comprehensive disease management programs was performed from January 2015 to March 2019. Data were extracted from medical records 1 year before and after the index date.

Results

200 patients were included (GOLD B: 156, GOLD E: 44; 2023 GOLD classification); mean age was 77.9 (SD 7.9) years; 48% were women, and 52% had biomass exposure as a COPD risk factor. The mean FEV1/FVC was 53.4% (SD 9.8), with an FEV1 of 52.7% (20.7). No differences were observed between clinical phenotypes in terms of airflow limitation. The geometric mean of absolute blood eosinophils was 197.58 (SD 2.09) cells/μL (range 0 to 3,020). Mean blood eosinophil count was higher in patients with smoking history and frequent exacerbators. At least one moderate and one severe exacerbation occurred in the previous year in 44 and 8% of patients, respectively; during the follow-up year 152 exacerbations were registered, 122 (80%) moderate and 30 (20%) severe. The highest rate of exacerbations in the follow-up year occurred in the subgroup of patients with the frequent exacerbator phenotype and eosinophils ≥300 cells/μL.

Discussion

In this cohort, the frequency of biomass exposure as a risk factor is considerable. High blood eosinophil count was related to smoking, and to the frequent exacerbator phenotype.

Development of a disease-specific health utility score for chronic obstructive pulmonary disease from a discrete choice experiment patient preference study

OBJECTIVES

While patient input to health technology assessment (HTA) has traditionally been of a qualitative nature, there is increasing interest to integrate quantitative evidence from patient preference studies into HTA decision making. Preference data can be used to generate disease-specific health utility data. We generated a health utility score for patients with chronic obstructive pulmonary disease (COPD) and consider its use within HTAs.

METHODS

Based on qualitative research, six symptoms were identified as important to COPD patients: shortness of breath, exacerbations, chronic cough, mucus secretion, sleep disturbance, and urinary incontinence. We employed a discrete choice experiment (DCE) and the random parameter logistic regression technique to estimate utility scores for all COPD health states. The relationship between patients' COPD health utility scores, self-perceived COPD severity, and EQ-5D-3L utility scores was analyzed, with data stratified according to disease severity and comorbidity subgroups.

RESULTS

The COPD health utility score had face validity, with utility scores negatively correlated with patients' self-perceived COPD severity. The correlation between the COPD health utility scores and EQ-5D-3L values was only moderate. While patient EQ-5D-3L scores were impacted by comorbidities, the COPD health utility score was less impacted by comorbid conditions.

CONCLUSIONS

Our COPD utility measure, derived from a DCE, provides a patient-centered health utility score and is more sensitive to the COPD health of the individual and less sensitive to other comorbidities. This disease-specific instrument should be considered alongside generic health-related quality of life instruments when valuing new COPD therapies in submissions to licensing and reimbursement agencies.

Rate of severe exacerbations, healthcare resource utilisation and clinical outcomes in patients with COPD in low-income and middle-income countries: results from the EXACOS International Study

INTRODUCTION

The EXAcerbations of Chronic obstructive lung disease (COPD) and their OutcomeS (EXACOS) International Study aimed to quantify the rate of severe exacerbations and examine healthcare resource utilisation (HCRU) and clinical outcomes in patients with COPD from low-income and middle-income countries.

METHODS

EXACOS International was an observational, cross-sectional study with retrospective data collection from medical records for a period of up to 5 years. Data were collected from 12 countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Dominican Republic, Guatemala, Hong Kong, Mexico, Panama, Russia and Taiwan. The study population comprised patients ≥40 years of age with COPD. Outcomes/variables included the prevalence of severe exacerbations, the annual rate of severe exacerbations and time between severe exacerbations; change in lung function over time (measured by the forced expiratory volume in 1 s (FEV1)); peripheral blood eosinophil counts (BECs) and the prevalence of comorbidities; treatment patterns; and HCRU.

RESULTS

In total, 1702 patients were included in the study. The study population had a mean age of 69.7 years, with 69.4% males, and a mean body mass index of 26.4 kg/m2. The mean annual prevalence of severe exacerbations was 20.1%, and 48.4% of patients experienced ≥1 severe exacerbation during the 5-year study period. As the number of severe exacerbations increased, the interval between successive exacerbations decreased. A statistically significant decrease in mean (SD) FEV1 from baseline to post-baseline was observed in patients with ≥1 severe exacerbation (1.23 (0.51) to 1.13 (0.52) L; p=0.0000). Mean BEC was 0.198 x109 cells/L, with 64.7% of patients having a BEC ≥0.1 x109 cells/L and 21.3% having a BEC ≥0.3 x109 cells/L. The most common comorbidity was hypertension (58.3%). An increasing number of severe exacerbations per year was associated with greater HCRU.

DISCUSSION

The findings presented here indicate that effective treatment strategies to prevent severe exacerbations in patients with COPD remain a significant unmet need in low-income and middle-income countries.

Excess healthcare resource utilization and costs for commercially insured patients with pulmonary arterial hypertension: A real-world data analysis

This retrospective study was conducted to evaluate all-cause healthcare resource utilization (HCRU) and costs in commercially insured patients living with pulmonary arterial hypertension (PAH) and explore end-of-life (EOL)-related HCRU and costs. Data from the IQVIA PharMetrics® Plus database (October 2014 to May 2020) were analyzed to identify adults (≥18 years) with PAH (PAH cohort) and those without PH (non-PH cohort). Patients were required to have data for ≥12 months before (baseline) and ≥6 months after (follow-up) the first observed PH diagnosis (index date) for PAH cohort or pseudo index date for non-PH cohort. A PAH EOL cohort was similarly constructed using a broader data window (October 2014 to March 2022) and ≥1 month of follow-up. Annualized all-cause HCRU and costs during follow-up were compared between PAH and non-PH cohorts after 1:1 matching on propensity scores derived from patient characteristics. EOL-related HCRU and costs were explored within 30 days and 6 months before the death date and estimated by a claims-based algorithm in PAH EOL cohort. The annual all-cause total ($183,616 vs. $20,212) and pharmacy ($115,926 vs. $7862; both p < 0.001) costs were 8 and 14 times higher, respectively, in the PAH cohort versus matched non-PH cohort (N = 386 for each). In PAH EOL cohort (N = 28), the mean EOL-related costs were $48,846 and $167,524 per patient within 30 days and 6 months before the estimated death, respectively. Hospitalizations contributed 58.8%-70.8% of the EOL-related costs. The study findings indicate substantial HCRU and costs for PAH. While pharmacy costs were one of the major sources, hospitalization was the primary driver for EOL-related costs.

An economic evaluation of chronic obstructive pulmonary disease clinical pathway in Saskatchewan, Canada: Data-driven techniques to identify cost-effectiveness among patient subgroups

BACKGROUND

Saskatchewan has implemented care pathways for several common health conditions. To date, there has not been any cost-effectiveness evaluation of care pathways in the province. The objective of this study was to evaluate the real-world cost-effectiveness of a chronic obstructive pulmonary disease (COPD) care pathway program in Saskatchewan.

METHODS

Using patient-level administrative health data, we identified adults (35+ years) with COPD diagnosis recruited into the care pathway program in Regina between April 1, 2018, and March 31, 2019 (N = 759). The control group comprised adults (35+ years) with COPD who lived in Saskatoon during the same period (N = 759). The control group was matched to the intervention group using propensity scores. Costs were calculated at the patient level. The outcome measure was the number of days patients remained without experiencing COPD exacerbation within 1-year follow-up. Both manual and data-driven policy learning approaches were used to assess heterogeneity in the cost-effectiveness by patient demographic and disease characteristics. Bootstrapping was used to quantify uncertainty in the results.

RESULTS

In the overall sample, the estimates indicate that the COPD care pathway was not cost-effective using the willingness to pay (WTP) threshold values in the range of $1,000 and $5,000/exacerbation day averted. The manual subgroup analyses show the COPD care pathway was dominant among patients with comorbidities and among patients aged 65 years or younger at the WTP threshold of $2000/exacerbation day averted. Although similar profiles as those identified in the manual subgroup analyses were confirmed, the data-driven policy learning approach suggests more nuanced demographic and disease profiles that the care pathway would be most appropriate for.

CONCLUSIONS

Both manual subgroup analysis and data-driven policy learning approach showed that the COPD care pathway consistently produced cost savings and better health outcomes among patients with comorbidities or among those relatively younger. The care pathway was not cost-effective in the entire sample.

Effect on Physical Position of Peak Inspiratory Flow in Stable COPD: An Observational Study

Background

We examined the effect of physical position on peak inspiratory flow (PIF) in patients with chronic obstructive pulmonary disease (COPD) using dry-powder inhalers (DPIs) with low‑medium internal resistance (R2) and/or high internal resistance (R5).

Methods

This prospective study in stable, ambulatory patients with spirometry-confirmed COPD evaluated the effect of 3 physical positions on maximal PIF achieved. Participants had PIFs of 30-90L/min (R5) or 60-90L/min (R2 DPIs) using the In-Check™ DIAL. PIF was measured in triplicate randomly in 3 positions that patients might be in while using their inhaler (standing, sitting, and semi-upright [supine position with the head of the bed at 45°, neck flexed forward]) against prescribed DPI resistance (R2/R5/both). Correlations between PIF and percentage decline in PIF between positions and differences in participant characteristics with >10% versus ≤10% PIF decline standing to semi-upright were calculated.

Results

A total of 76 participants (mean age, 65.2 years) had positional measurements; 59% reported seated DPI use at home. The mean (standard deviation) PIF standing, sitting, and semi-upright was 80.7 (13.4), 77.8 (14.3), and 74.0 (14.5) L/min, respectively, for R2 and 51.1 (9.52), 48.6 (9.84), and 45.8 (7.69) L/min, respectively, for R5 DPIs. PIF semi-upright was significantly lower than sitting and standing (R2; P < 0.0001) and standing (R5; P= 0.002). Approximately half of the participants had >10% decline in PIF from standing to semi-upright. Patient characteristics exceeding the 0.10 absolute standardized difference threshold with the decline in PIF for both the R2 and R5 DPIs were waist-to-hip ratio, modified Medical Research Council dyspnea score, and postbronchodilator percentage predicted forced vital capacity and PIF by spirometry.

Conclusions

PIF was significantly affected by physical position regardless of DPI resistance. PIF was highest when standing and lowest when semi-upright. We recommend that patients with COPD stand while using an R2 or R5 DPI. Where unfeasible, the position should be sitting rather than semi-upright. ClinicalTrials.gov identifier NCT04168775.

The six-minute step test can predict COPD exacerbations: a 36-month follow-up study

The six-minute step test (6MST) has been shown to be effective in assessing exercise capacity in individuals with COPD regardless of severity and, despite its easy execution, accessibility and validity, information on the prognostic power of this test remains uncertain. The aim of this study is to investigate whether the 6MST can predict the occurrence of exacerbations in patients with COPD. This is a prospective cohort study with a 36-month follow-up in patients with COPD. All patients completed a clinical assessment, followed by pulmonary function testing and a 6MST. The 6MST was performed on a 20 cm high step; heart rate, blood pressure, oxygen saturation, BORG dyspnea and fatigue were collected. Sixty-four patients were included in the study, the majority being elderly men. Performance on the 6MST demonstrated lower performance compared to normative values proposed in the literature, indicating a reduced functional capacity. Kaplan Meier analysis revealed that ≤ 59 steps climbed during the 6MST was a strong predictor of COPD exacerbation over a 36-month follow-up. We have identified a minimal threshold number of steps (≤ 59) obtained through the 6MST may be able predict the risk of exacerbations in patients with COPD.

Gut microbiota was highly related to the immune status in chronic obstructive pulmonary disease patients

This study aimed to explore the profile of gut microbiota and immunological state in COPD patients. 80 fecal and blood samples were collected from 40 COPD patients and 40 healthy controls (HC) and analyzed with 16s-rRNA gene sequencing and immunofactor omics analysis to investigate the profile of gut microbiota and immunologic factors (IFs). The linear discriminant analysis (LDA) effect size (LefSe) was used to determine the biomarker's taxa. The random forest and LASSO regression analysis were executed to screen IFs and develop an IFscore model. The correlation between gut microbiota and IFs, along with the IFscore and the diversity of gut microbiota, was evaluated with the Spearman analysis. The α and β diversity showed that the composition and distribution of gut microbiota in the COPD group differed from that of the HC group. 7 differential taxa at the phylum level and 17 differential taxa at the genus level were found. LefSe analysis screened out 5 biomarker's taxa. 32 differential IFs (up-regulated 27 IFs and down-regulated 5 IFs) were identified between two groups, and 5 IFs (CCL3, CXCL9, CCL7, IL2, IL4) were used to construct an IFscore model. The Spearman analysis revealed that 29 IFs were highly related to 5 biomarker's taxa and enriched in 16 pathways. Furthermore, the relationship between the IFscore and gut microbiota diversity was very close. The gut microbiota and IFs profile in COPD patients differed from that in healthy individuals. Gut microbiota was highly related to the immune status in COPD patients.

Assessment of Behavioral Risk Factors in Chronic Obstructive Airway Diseases of the Lung Associated with Metabolic Syndrome

BACKGROUND

Diet and lifestyle play important roles in preventing and improving chronic diseases, and evaluating behavioral risk factors in these pathologies allows for efficient management.

METHODS

A clinical study by screening biochemical parameters and pulmonary function was carried out to evaluate behavioral risk factors in obstructive pulmonary disease associated with metabolic syndrome.

RESULTS

Of the total of 70 patients included in the clinical study, 46 were men and 24 were women (χ2 = 3.9, p = 0.168). Forty-eight patients presented at least three met risk criteria associated with the metabolic syndrome (19 women and 29 men). Regarding the assessment of lung function, only 7 of the patients presented normal spirometry values (χ2 = 75.28, p < 0.001), and the other 63 patients presented with ventilatory dysfunction; most (over 80%) declared that they were smokers or had smoked in the past (χ2 = 5.185, p = 0.075). In terms of body weight, 45 of the patients are overweight or obese, most of them declaring that they do not consume enough vegetable products, they consume large amounts of foods of animal origin (meat, milk, eggs) but also super processed foods (food products type of junk food), do not hydrate properly, and are predominantly sedentary people (54 of the patients do no physical activity at all; χ2 = 2.12, p = 0.713).

CONCLUSION

From the statistical processing of the data, it is noted that insufficient hydration, low consumption of vegetables, increased consumption of hyper-caloric food products rich in additives, sedentary lifestyle, and smoking are the main disruptive behavioral factors that worsen the health status in lung disease associated with the metabolic syndrome. An important conclusion emerging from the study is that the imbalances that aggravate obstructive lung diseases are generated by unhealthy food and an unbalanced lifestyle.

Pilot Testing of a Lightweight, Pulmonary Assist System in an Ambulatory Sheep Model of Destination Therapy Respiratory Support

A new, lightweight (2.3 kg), ambulatory pulmonary assist system (PAS) underwent preliminary evaluation in ambulatory sheep. The PAS was purposefully designed for long-term extracorporeal respiratory support for chronic lung disease and utilizes a novel, small (0.9 m 2 surface area) gas exchanger, the pulmonary assist device, with a modified Heart Assist 5 pump fitting in a small wearable pack. Prototype PAS were attached to two sheep in venovenous configuration for 7 and 14 days, evaluating ability to remain thrombus free; maintain gas exchange and blood flow resistance; avoid biocompatibility-related complications while allowing safe ambulation. The PAS achieved 1.56 L/min of flow at 10.8 kRPM with a 24 Fr cannula in sheep one and 2.0 L/min at 10.5 kRPM with a 28 Fr cannula in sheep 2 without significant change. Both sheep walked freely, demonstrating the first application of truly ambulatory ECMO in sheep. While in vitro testing evaluated PAS oxygen transfer rates of 104.6 ml/min at 2 L/min blood flow, oxygen transfer rates averaged 60.6 ml/min and 70.6 ml/min in studies 1 and 2, due to average hemoglobin concentrations lower than humans (8.9 and 10.5 g/dl, respectively). The presented cases support uncomplicated ambulation using the PAS.

Real-World Cost-Consequence Analysis of an Integrated Chronic Disease Management Program in Saskatchewan, Canada

An integrated disease management program otherwise called a clinical pathway was recently implemented in Saskatchewan, Canada for patients living with chronic obstructive pulmonary disease (COPD). This study compared the real-world costs and consequences of the COPD clinical pathway program with 2 control treatment programs. The study comprised adult COPD patients in Regina (clinical pathway group, N = 759) matched on propensity scores to 2 independent control groups of similar adults in (1) Regina (historical controls, N = 759) and (2) Saskatoon (contemporaneous controls, N = 759). The study measures included patient-level healthcare costs and acute COPD exacerbation outcomes, both tracked in population-based administrative health data over a one-year follow-up period. Analyses included Cox proportional hazards models and differences in means between groups. The bias-corrected and accelerated bootstrap method was used to calculate 95% confidence intervals (CI). The COPD pathway patients had lower risks of moderate (hazard ratio [HR] =0.57, 95% CI [0.40-0.83]) and severe (HR = 0.43, 95% CI [0.28-0.66]) exacerbations compared to the historical control group, but similar risks compared with the contemporaneous control group. The COPD pathway patients experienced fewer episodes of exacerbations compared with the historical control group (mean difference = -0.30, 95% CI [-0.40, -0.20]) and the contemporaneous control group (mean difference = -0.12, 95% CI [-0.20, -0.03]). Average annual healthcare costs in Canadian dollars were marginally higher among patients in the COPD clinical pathway (mean = $10 549, standard deviation [SD] =$18 149) than those in the contemporaneous control group ($8841, SD = $17 120), but comparable to the historical control group ($10 677, SD = $21 201). The COPD pathway provides better outcomes at about the same costs when compared to the historical controls, but only slightly better outcomes and at a marginally higher cost when compared to the contemporaneous controls.

Global mortality and readmission rates following COPD exacerbation-related hospitalisation: a meta-analysis of 65 945 individual patients

Background

Exacerbations of COPD (ECOPD) have a major impact on patients and healthcare systems across the world. Precise estimates of the global burden of ECOPD on mortality and hospital readmission are needed to inform policy makers and aid preventive strategies to mitigate this burden. The aims of the present study were to explore global in-hospital mortality, post-discharge mortality and hospital readmission rates after ECOPD-related hospitalisation using an individual patient data meta-analysis (IPDMA) design.

Methods

A systematic review was performed identifying studies that reported in-hospital mortality, post-discharge mortality and hospital readmission rates following ECOPD-related hospitalisation. Data analyses were conducted using a one-stage random-effects meta-analysis model. This study was conducted and reported in accordance with the PRISMA-IPD statement.

Results

Data of 65 945 individual patients with COPD were analysed. The pooled in-hospital mortality rate was 6.2%, pooled 30-, 90- and 365-day post-discharge mortality rates were 1.8%, 5.5% and 10.9%, respectively, and pooled 30-, 90- and 365-day hospital readmission rates were 7.1%, 12.6% and 32.1%, respectively, with noticeable variability between studies and countries. Strongest predictors of mortality and hospital readmission included noninvasive mechanical ventilation and a history of two or more ECOPD-related hospitalisations <12 months prior to the index event.

Conclusions

This IPDMA stresses the poor outcomes and high heterogeneity of ECOPD-related hospitalisation across the world. Whilst global standardisation of the management and follow-up of ECOPD-related hospitalisation should be at the heart of future implementation research, policy makers should focus on reimbursing evidence-based therapies that decrease (recurrent) ECOPD.

Long- versus short-duration systemic corticosteroid regimens for acute exacerbations of COPD: A systematic review and meta-analysis of randomized trials and cohort studies

While systemic corticosteroids quicken patient recovery during acute exacerbations of COPD, they also have many adverse effects. The optimal duration of corticosteroid administration remains uncertain. We performed a systematic review and meta-analysis to compare patient outcomes between short- (≤7 days) and long- (>7 days) corticosteroid regimens in adults with acute exacerbations of COPD. MEDLINE, EMBASE, CENTRAL, and hand searches were used to identify eligible studies. Risk of bias was assessed using the Cochrane RoB 2.0 tool and ROBINS-I. Data were summarized as ORs (odds ratios) or MDs (mean differences) whenever possible and qualitatively described otherwise. A total of 11532 participants from eight RCTs and three retrospective cohort studies were included, with 1296 from seven RCTs and two cohort studies eligible for meta-analyses. Heterogeneity was present in the methodology and settings of the studies. The OR (using short duration as the treatment arm) for mortality was 0.76 (95% CI = 0.40-1.44, n = 1055). The MD for hospital length-of-stay was -0.91 days (95% CI = -1.81--0.02 days, n = 421). The OR for re-exacerbations was 1.31 (95% CI = 0.90-1.90, n = 552). The OR for hyperglycemia was 0.90 (95% CI = 0.60-1.33, n = 423). The OR for infection incidence was 0.96 (95% CI = 0.59-1.156, n = 389). The MD for one-second forced expiratory volume change was -18.40 mL (95% CI = -111.80-75.01 mL, n = 161). The RCTs generally had low or unclear risks of bias, while the cohort studies had serious or moderate risks of bias. Our meta-analyses were affected by imprecision due to insufficient data. Some heterogeneity was present in the results, suggesting population, setting, and treatment details are potential prognostic factors. Our evidence suggests that short-duration treatments are not worse than long-duration treatments in moderate/severe exacerbations and may lead to considerably better outcomes in milder exacerbations. This supports the current GOLD guidelines. Trial registration: Our protocol is registered in PROSPERO: CRD42023374410.

Body Composition, Physical Function and Exercise Capacity in Chronic Obstructive Pulmonary Disease

Current literature yields unequivocal results regarding the effect of body composition on physical function in patients with chronic obstructive pulmonary disease and disproportionately includes a majority of males. The purpose of this study was to determine whether specific body composition measures are significantly associated with physical function and exercise capacity in patients with chronic obstructive pulmonary disease with equal representation of males and females. Independent variables included sex, total body mass, total body lean and fat mass, appendicular total mass, and appendicular lean and fat mass. Dependent variables included peak oxygen consumption, 6-minute walk distance and self-reported physical function. Patients (n = 170) with dual-energy X-ray absorptiometry data, 6-minute walk distance, and self-reported physical function were used for these analyses. A sub-set of 145 of these patients with peak oxygen consumption data were also analysed. Hierarchical multiple regression analysis was used to determine if sex and body composition measures correlated with physical function and exercise capacity and if they explained additional variance after controlling for disease severity. After controlling for disease severity, appendicular lean mass, total body fat mass, and sex explained an additional 16.5% of the variance in peak oxygen consumption (p < 0.001). Appendicular lean mass explained an additional 8.9% of the variance in 6-minute walk distance (p < 0.001) and an additional 2.5% of the variance in self-reported physical function (p = 0.057). Body composition measures may further predict exercise capacity, 6-minute walk distance, and self-reported physical function in patients with chronic obstructive pulmonary disease.

A Macrophage-Related Gene Signature for Identifying COPD Based on Bioinformatics and ex vivo Experiments

Background

This study aims to investigate the association between immune cells and the development of COPD, while providing a new method for the diagnosis of COPD according to the changes in immune microenvironment.

Methods

In this study, the "CIBERSORT" algorithm was used to estimate the tissue infiltration of 22 types of immune cells in GSE20257 and GSE10006. The "limma" package was used for differentially expressed analysis. The key modules associated with vital immune cells were identified using WGCNA. GO and KEGG enrichment analysis revealed the biological functions of the candidate genes. Ultimately, a novel diagnostic prediction model was constructed via machine learning methods and multivariate logistic regression analysis based on GSE20257. Furthermore, we examined the stability of the model on one internal test set (GSE10006), three external test sets (GSE8545, GSE57148 and GSE76925), one single-cell transcriptome dataset (GSE167295), macrophages (THP-M cells) and lung tissue from COPD patients.

Results

M0 macrophages (AUC > 0.7 in GSE20257 and GSE10006) were considered as the most important immune cells through exploring the immune microenvironment landscapes in COPD patients and healthy controls. The differentially expressed genes from GSE20257 and GSE10006 were divided into six and five modules via WGCNA, respectively. The green module in GSE20257 (cor = 0.41, P < 0.001) and the brown module in GSE10006 (cor = 0.67, P < 0.001) were highly correlated with M0 macrophages and were selected as key modules. Forty-one intersected genes obtained from two modules were primarily involved in regulation of cytokine production, regulation of innate immune response, specific granule, phagosome, lysosome, ferroptosis, and other biological processes. On the basis of the candidate genetic markers further characterized via the "Boruta" and "LASSO" algorithm for COPD, a diagnostic model comprising CLEC5A, FTL and SLC2A3 was constructed, which could accurately distinguish COPD patients from healthy controls in multiple datasets. GSE20257 as the training set has an AUC of 0.916. The AUCs of the internal test set and three external test sets were 0.873, 0.932, 0.675 and 0.688, respectively. Single-cell sequencing analysis suggested that CLEC5A, FTL and SLC2A3 were expressed in macrophages from COPD patients. The expressions of CLEC5A, FTL and SLC2A3 were up-regulated in THP-M cells and lung tissue from COPD patients.

Conclusion

According to the variations of immune microenvironment in COPD patients, we constructed and validated a novel macrophage M0-associated diagnostic model with satisfactory predictive value. CLEC5A, FTL and SLC2A3 are expected to be promising targets of immunotherapy in COPD.

The impact of the immune system on lung injury and regeneration in COPD

COPD is a devastating respiratory condition that manifests via persistent inflammation, emphysema development and small airway remodelling. Lung regeneration is defined as the ability of the lung to repair itself after injury by the proliferation and differentiation of progenitor cell populations, and becomes impaired in the COPD lung as a consequence of cell intrinsic epithelial stem cell defects and signals from the micro-environment. Although the loss of structural integrity and lung regenerative capacity are critical for disease progression, our understanding of the cellular players and molecular pathways that hamper regeneration in COPD remains limited. Intriguingly, despite being a key driver of COPD pathogenesis, the role of the immune system in regulating lung regenerative mechanisms is understudied. In this review, we summarise recent evidence on the contribution of immune cells to lung injury and regeneration. We focus on four main axes: 1) the mechanisms via which myeloid cells cause alveolar degradation; 2) the formation of tertiary lymphoid structures and the production of autoreactive antibodies; 3) the consequences of inefficient apoptotic cell removal; and 4) the effects of innate and adaptive immune cell signalling on alveolar epithelial proliferation and differentiation. We finally provide insight on how recent technological advances in omics technologies and human ex vivo lung models can delineate immune cell-epithelium cross-talk and expedite precision pro-regenerative approaches toward reprogramming the alveolar immune niche to treat COPD.

Arginine, Transsulfuration, and Folic Acid Pathway Metabolomics in Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

There is an increasing interest in biomarkers of nitric oxide dysregulation and oxidative stress to guide management and identify new therapeutic targets in patients with chronic obstructive pulmonary disease (COPD). We conducted a systematic review and meta-analysis of the association between circulating metabolites within the arginine (arginine, citrulline, ornithine, asymmetric, ADMA, and symmetric, SDMA dimethylarginine), transsulfuration (methionine, homocysteine, and cysteine) and folic acid (folic acid, vitamin B6, and vitamin B12) metabolic pathways and COPD. We searched electronic databases from inception to 30 June 2023 and assessed the risk of bias and the certainty of evidence. In 21 eligible studies, compared to healthy controls, patients with stable COPD had significantly lower methionine (standardized mean difference, SMD = -0.50, 95% CI -0.95 to -0.05, p = 0.029) and folic acid (SMD = -0.37, 95% CI -0.65 to -0.09, p = 0.009), and higher homocysteine (SMD = 0.78, 95% CI 0.48 to 1.07, p < 0.001) and cysteine concentrations (SMD = 0.34, 95% CI 0.02 to 0.66, p = 0.038). Additionally, COPD was associated with significantly higher ADMA (SMD = 1.27, 95% CI 0.08 to 2.46, p = 0.037), SDMA (SMD = 3.94, 95% CI 0.79 to 7.08, p = 0.014), and ornithine concentrations (SMD = 0.67, 95% CI 0.13 to 1.22, p = 0.015). In subgroup analysis, the SMD of homocysteine was significantly associated with the biological matrix assessed and the forced expiratory volume in the first second to forced vital capacity ratio, but not with age, study location, or analytical method used. Our study suggests that the presence of significant alterations in metabolites within the arginine, transsulfuration, and folic acid pathways can be useful for assessing nitric oxide dysregulation and oxidative stress and identifying novel treatment targets in COPD. (PROSPERO registration number: CRD42023448036.).

The global economic burden of chronic obstructive pulmonary disease for 204 countries and territories in 2020-50: a health-augmented macroeconomic modelling study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide and imposes a substantial economic burden. Gaining a thorough understanding of the economic implications of COPD is an important prerequisite for sound, evidence-based policy making. We aimed to estimate the macroeconomic burden of COPD for each country and establish its distribution across world regions.

METHODS

In this health-augmented macroeconomic modelling study we estimated the macroeconomic burden of COPD for 204 countries and territories over the period 2020-50. The model accounted for (1) the effect of COPD mortality and morbidity on labour supply, (2) age and sex specific differences in education and work experience among those affected by COPD, and (3) the impact of COPD treatment costs on physical capital accumulation. We obtained data from various public sources including the Global Burden of Disease Study 2019, the World Bank database, and the literature. The macroeconomic burden of COPD was assessed by comparing gross domestic product (GDP) between a scenario projecting disease prevalence based on current estimates and a counterfactual scenario with zero COPD prevalence from 2020 to 2050.

FINDINGS

Our findings suggest that COPD will cost the world economy INT$4·326 trillion (uncertainty interval 3·327-5·516; at constant 2017 prices) in 2020-50. This economic effect is equivalent to a yearly tax of 0·111% (0·085-0·141) on global GDP. China and the USA face the largest economic burdens from COPD, accounting for INT$1·363 trillion (uncertainty interval 1·034-1·801) and INT$1·037 trillion (0·868-1·175), respectively.

INTERPRETATION

The macroeconomic burden of COPD is large and unequally distributed across countries, world regions, and income levels. Our study stresses the urgent need to invest in global efforts to curb the health and economic burdens of COPD. Investments in effective interventions against COPD do not represent a burden but could instead provide substantial economic returns in the foreseeable future.

FUNDING

Alexander von Humboldt Foundation, National Natural Science Foundation of China, CAMS Innovation Fund for Medical Science, Chinese Academy of Engineering project, Chinese Academy of Medical Sciences and Peking Union Medical College project, and Horizon Europe.

TRANSLATIONS

For the Chinese and German translations of the abstract see Supplementary Materials section.

Understanding the Patient Experience of Home-Based Pulmonary Rehabilitation with Health Coaching for COPD: A Qualitative Interview Study

Background

We recently reported on a randomized trial of home-based pulmonary rehabilitation (PR) for chronic obstructive pulmonary disease (COPD) that showed improvement in all domains of quality of life, accelerometry-measured physical activity, and self-management. In this current study, we used a theoretical framework to help us gain an in-depth understanding of how patients experience complex, multi-component programs to help uncover factors related to behavior change and to inform program scale-up in other populations.

Study Design and Methods

The parent trial was conducted with COPD patients receiving care at an academic medical center and a community health system in the upper Midwest. The 12-week PR intervention included 3 daily video-guided exercises, activity monitors, and weekly telephonic health coaching. Trial participants were eligible to participate in an individual phone interview about their experience if they completed the intervention within the prior 12 months.. Analysis of verbatim transcripts followed an inductive thematic approach followed by deductive categorization and interpretation using a theoretical model: the Capability, Opportunity, Motivation-Behavior (COM-B) model developed for linking intervention functions to aspects of behavioral change.

Results

Among 32 eligible program participants,32 were approached, and 15 completed interviews between October 19, 2021, and January 13, 2022. The COM-B model and recommendations for program improvement were observed in the primary findings.

Discussion

Participants' feedback highlighted how the health coaching bolstered skills and confidence among individuals with the poorest function at program enrollment and how improved physical function and mood led to motivation. It also highlighted the roles of technology and telephonic support in a home-based program. Suggestions for improvement included providing exercise variations.

Gender-specific disease trajectories prior to the onset of COPD allow individualized screening and early intervention

BACKGROUND

Nation-wide hospitalization databases include diagnostic information at the level of an entire population over an extended period of time. Comorbidity network and early disease development can be unveiled. Chronic obstructive pulmonary disease (COPD) is an underdiagnosed condition for which it is crucial to identify early disease indicators. The identification of gender-specific conditions preceding the onset of COPD may reveal disease progression patterns allowing for early diagnosis and intervention. The objective of the study was to investigate the antecedent hospitalization history of patients newly diagnosed with COPD and to retrace a gender-specific trajectory of coded entities prior to the onset of COPD.

MATERIAL AND METHODS

A population-wide hospitalization database including information about all hospitalizations in Switzerland between 2002 and 2018 was used. COPD cases were extracted from the database and comorbidities occurring prior to the onset of COPD identified. Comorbidities significantly over-represented in COPD compared with a 1:1, age- and sex-matched control population were identified and their longitudinal evolution was analyzed.

RESULTS

Between 2002 and 2018, 697,714 hospitalizations with coded COPD were recorded in Switzerland. Sixty-two diagnoses were significantly over-represented before onset of COPD. These preceding comorbidities included both well-established conditions and novel links to COPD. Early pre-conditions included nicotine and alcohol abuse, obesity and cardiovascular diseases. Later comorbidities included atrial fibrillation, diseases of the genitourinary system and pneumonia. Atherosclerotic heart diseases were more prevalent in males, whereas hypothyroidism, varicose and intestinal disorders were more frequent in females. Disease trajectories were validated using an independent data set.

CONCLUSIONS

Gender-specific disease trajectories highlight early indicators and pathogenetic links between COPD and antecedent diseases and could allow for early detection and intervention.

Identifying risk factors for COPD and adult-onset asthma: an umbrella review

BACKGROUND

COPD and adult-onset asthma (AOA) are the most common noncommunicable respiratory diseases. To improve early identification and prevention, an overview of risk factors is needed. We therefore aimed to systematically summarise the nongenetic (exposome) risk factors for AOA and COPD. Additionally, we aimed to compare the risk factors for COPD and AOA.

METHODS

In this umbrella review, we searched PubMed for articles from inception until 1 February 2023 and screened the references of relevant articles. We included systematic reviews and meta-analyses of observational epidemiological studies in humans that assessed a minimum of one lifestyle or environmental risk factor for AOA or COPD.

RESULTS

In total, 75 reviews were included, of which 45 focused on risk factors for COPD, 28 on AOA and two examined both. For asthma, 43 different risk factors were identified while 45 were identified for COPD. For AOA, smoking, a high body mass index (BMI), wood dust exposure and residential chemical exposures, such as formaldehyde exposure or exposure to volatile organic compounds, were amongst the risk factors found. For COPD, smoking, ambient air pollution including nitrogen dioxide, a low BMI, indoor biomass burning, childhood asthma, occupational dust exposure and diet were amongst the risk factors found.

CONCLUSIONS

Many different factors for COPD and asthma have been found, highlighting the differences and similarities. The results of this systematic review can be used to target and identify people at high risk for COPD or AOA.

Gut microbiota and chronic obstructive pulmonary disease: a Mendelian randomization study

Background

A growing number of studies implies a strong association between gut microbiota and chronic obstructive pulmonary disease (COPD). However, the causal impact between gut microbiota and COPD remains unclear. As a result, we used a two-sample Mendelian randomization (MR) method to investigate the connection between gut microbiota and COPD in this study.

Methods

The largest available genome-wide association study (GWAS) of gut microbiota was obtained from the MiBioGen consortium. Summary-level dataset for COPD were obtained from the FinnGen consortium. The main analysis method for determining the causal link between gut microbiota and COPD was inverse variance weighted (IVW). Subsequently, pleiotropy and heterogeneity tests were performed to determine the reliability of the results.

Results

IVW method identified 9 bacterial taxa nominally associated with the risk of COPD. Class Actinobacteria (p = 0.020), genus Allisonella (p = 0.024), genus Coprococcus2 (p = 0.002) and genus Oscillospira (p = 0.018) were protective against COPD. In addition, order Desulfovibrionales (p = 0.011), family Desulfovibrionaceae (p = 0.039), family Peptococcaceae (p = 0.020), family Victivallaceae (p = 0.012) and genus Marvinbryantia (p = 0.017) were associated with a higher risk of COPD. No pleiotropy or heterogeneity were found.

Conclusion

According to the findings of this MR analysis, a causal relationship exists between certain gut microbiota and COPD. New insights into the mechanisms of COPD mediated by gut microbiota are provided.

Prognostic Nutritional Index (PNI) as a Potential Prognostic Tool for Exacerbation of COPD in Elderly Patients

Purpose

In COPD, exacerbation of the disorder causes a deterioration in the quality-of-life and worsens respiratory dysfunction, leading to a poor prognosis. In recent years, nutritional indices have been reported as significant prognostic factors in various chronic diseases. However, the relationship between nutritional indicators and prognosis in elderly subjects with COPD has not been investigated.

Patients and methods

We enrolled 91 subjects who received COPD assessment tests (CAT), spirometry, blood tests, and multidetector computed tomography (MDCT). We divided the subjects into two groups according to age (<75 years (n=57) and ≥ 75 years (n=34)). The prognostic nutritional index (PNI) was used to assess immune-nutritional status and was calculated as 10 x serum albumin + 0.005 x total lymphocyte count. We then examined the relationship between PNI and clinical parameters, including exacerbation events.

Results

There was no significant correlation between the PNI and CAT, the FEV₁%pred, or low attenuation volume percentage (LAV%). In the elderly group, there were significant differences between the groups with or without exacerbation in the CAT and PNI (p=0.008, p=0.004, respectively). FEV₁%pred, neutrophil-to-lymphocyte ratio (NLR) and LAV% did not differ between the two groups. The analytical model combining CAT and PNI improved the prediction of exacerbations in the elderly subjects (p=0.0068).

Conclusion

In elderly subjects with COPD, CAT were associated significantly with the risk of COPD exacerbation, with PNI also a potential predictor. The combined assessment of CAT and PNI may be a useful prognostic tool in subjects with COPD.

Accuracy of Nodule Volume and Airway Wall Thickness Measurement Using Low-Dose Chest CT on a Photon-Counting Detector CT Scanner

OBJECTIVES

A comparison of high-resolution photon-counting detector computed tomography (PCD-CT) versus energy-integrating detector (EID) CT via a phantom study using low-dose chest CT to evaluate nodule volume and airway wall thickness quantification.

MATERIALS AND METHODS

Twelve solid and ground-glass lung nodule phantoms with 3 diameters (5 mm, 8 mm, and 10 mm) and 2 shapes (spherical and star-shaped) and 12 airway tube phantoms (wall thicknesses, 0.27-1.54 mm) were placed in an anthropomorphic chest phantom. The phantom was scanned with EID-CT and PCD-CT at 5 dose levels (CTDI vol = 0.1-0.8 mGy at Sn-100 kV, 7.35 mGy at 120 kV). All images were iteratively reconstructed using matched kernels for EID-CT and medium-sharp kernel (MK) PCD-CT and an ultra-sharp kernel (USK) PCD-CT kernel, and image noise at each dose level was quantified. Nodule volumes were measured using semiautomated segmentation software, and the accuracy was expressed as the percentage error between segmented and reference volumes. Airway wall thicknesses were measured, and the root-mean-square error across all tubes was evaluated.

RESULTS

MK PCD-CT images had the lowest noise. At 0.1 mGy, the mean volume accuracy for the solid and ground-glass nodules was improved in USK PCD-CT (3.1% and 3.3% error) compared with MK PCD-CT (9.9% and 10.2% error) and EID-CT images (11.4% and 9.2% error), respectively. At 0.2 mGy and 0.8 mGy, the wall thickness root-mean-square error values were 0.42 mm and 0.41 mm for EID-CT, 0.54 mm and 0.49 mm for MK PCD-CT, and 0.23 mm and 0.16 mm for USK PCD-CT.

CONCLUSIONS

USK PCD-CT provided more accurate lung nodule volume and airway wall thickness quantification at lower radiation dose compared with MK PCD-CT and EID-CT.

Prevention of Re-Hospitalization for Acute Exacerbations: Perspectives of People with Chronic Obstructive Pulmonary Disease: A Qualitative Study

Purpose

Current guidelines for prevention of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) reflect clinical understanding of the causes of exacerbations but with a limited recognition of person-specific contributing factors. As part of a randomized trial of a person-centered intervention aiming to promote self-determination, we describe personal perspectives of those with chronic obstructive pulmonary disease (COPD) on what they saw as the causes and best ways to stay well and prevent rehospitalization after an AECOPD.

Patients and Methods

Twelve participants (mean age 69.3 years, six female, six male; eight New Zealand European, two Māori, one Pacific, and one other) were interviewed about their experiences of staying well and out of hospital. Data were collected via individual semi-structured interviews one year following an index hospital admission for AECOPD and focused on the participants' views and experiences of their health condition, their beliefs about staying well, and the causes of and factors preventing further exacerbations and hospitalizations. Data were analyzed using constructivist grounded theory methods.

Results

Three main themes were identified that described participants' views on what helped or hindered them to stay well and out of hospital: 1) Being Positive: The importance of having a positive mindset; 2) Being Proactive: Practical steps to reduce the risk of, and consequences from, episodes of AECOPD; and 3) Being in Control: Feeling in command of one's life and health. Each of these was affected by Being Connected: The influence of significant others, particularly close family.

Conclusion

This research expands our understanding of how patients manage COPD and adds patient perspectives to current knowledge on how to prevent recurrent AECOPD. Programs which promote self-efficacy and positivity would be beneficial additions to AECOPD prevention strategies, as could the inclusion of family or significant others in wellbeing plans.

Agarwood Oil Nanoemulsion Attenuates Cigarette Smoke-Induced Inflammation and Oxidative Stress Markers in BCi-NS1.1 Airway Epithelial Cells

Chronic obstructive pulmonary disease (COPD) is an irreversible inflammatory respiratory disease characterized by frequent exacerbations and symptoms such as cough and wheezing that lead to irreversible airway damage and hyperresponsiveness. The primary risk factor for COPD is chronic cigarette smoke exposure, which promotes oxidative stress and a general pro-inflammatory condition by stimulating pro-oxidant and pro-inflammatory pathways and, simultaneously, inactivating anti-inflammatory and antioxidant detoxification pathways. These events cause progressive damage resulting in impaired cell function and disease progression. Treatments available for COPD are generally aimed at reducing the symptoms of exacerbation. Failure to regulate oxidative stress and inflammation results in lung damage. In the quest for innovative treatment strategies, phytochemicals, and complex plant extracts such as agarwood essential oil are promising sources of molecules with antioxidant and anti-inflammatory activity. However, their clinical use is limited by issues such as low solubility and poor pharmacokinetic properties. These can be overcome by encapsulating the therapeutic molecules using advanced drug delivery systems such as polymeric nanosystems and nanoemulsions. In this study, agarwood oil nanoemulsion (agarwood-NE) was formulated and tested for its antioxidant and anti-inflammatory potential in cigarette smoke extract (CSE)-treated BCi-NS1.1 airway basal epithelial cells. The findings suggest successful counteractivity of agarwood-NE against CSE-mediated pro-inflammatory effects by reducing the expression of the pro-inflammatory cytokines IL-1α, IL-1β, IL-8, and GDF-15. In addition, agarwood-NE induced the expression of the anti-inflammatory mediators IL-10, IL-18BP, TFF3, GH, VDBP, relaxin-2, IFN-γ, and PDGF. Furthermore, agarwood-NE also induced the expression of antioxidant genes such as GCLC and GSTP1, simultaneously activating the PI3K pro-survival signalling pathway. This study provides proof of the dual anti-inflammatory and antioxidant activity of agarwood-NE, highlighting its enormous potential for COPD treatment.

Levels of immunoglobulin isotypes in serum and respiratory samples of patients with chronic obstructive pulmonary disease: protocol for a systematic review and meta-analysis

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is an inflammatory respiratory disorder characterised by the progressive worsening of lung function. Acute exacerbation of COPD (AECOPD) is a leading contributor to patient morbidity, mortality and hospitalisations. The clinical significance of immunoglobulin (Ig) levels in COPD patients is not well established and is in need of further investigation.

METHODS AND ANALYSIS

We will conduct a systematic review to describe levels of different Ig isotypes (IgG, IgA and IgM) in various samples (serum, sputum and bronchoalveolar lavage) of patients with COPD. IgE levels in COPD patients have been researched and reviewed extensively and hence will be excluded from this review. IgD levels will also be excluded from the review as there is a paucity of data on IgD levels in COPD patients. The primary outcome of interest in this systematic review is assessing Ig isotype levels in patients with COPD. Secondary outcomes that will be assessed include the differences between Ig isotype levels in COPD patients compared with healthy controls, as well as the relationships between Ig isotype levels and key clinical variables, including COPD severity, incidence of AECOPD and AECOPD severity. Embase and Ovid MEDLINE will be used to search for non-randomised studies published from 1946 to October 2022 that report our prespecified primary and secondary outcomes. As per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol, retrieved studies will undergo a two-phase screening process conducted by two independent reviewers. Prespecified primary and secondary outcomes will be extracted from eligible studies, and descriptive statistics will be used to analyse extracted outcomes. The risk of bias will be assessed using the Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) tool.

ETHICS AND DISSEMINATION

Ethics approval is not required as this is a protocol for a systematic review and meta-analysis. Findings will be disseminated through peer-reviewed publications and other formats including conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42020192220.

Biological and Genetic Mechanisms of COPD, Its Diagnosis, Treatment, and Relationship with Lung Cancer

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent chronic adult diseases, with significant worldwide morbidity and mortality. Although long-term tobacco smoking is a critical risk factor for this global health problem, its molecular mechanisms remain unclear. Several phenomena are thought to be involved in the evolution of emphysema, including airway inflammation, proteinase/anti-proteinase imbalance, oxidative stress, and genetic/epigenetic modifications. Furthermore, COPD is one main risk for lung cancer (LC), the deadliest form of human tumor; formation and chronic inflammation accompanying COPD can be a potential driver of malignancy maturation (0.8-1.7% of COPD cases develop cancer/per year). Recently, the development of more research based on COPD and lung cancer molecular analysis has provided new light for understanding their pathogenesis, improving the diagnosis and treatments, and elucidating many connections between these diseases. Our review emphasizes the biological factors involved in COPD and lung cancer, the advances in their molecular mechanisms' research, and the state of the art of diagnosis and treatments. This work combines many biological and genetic elements into a single whole and strongly links COPD with lung tumor features.

Chronic Obstructive Pulmonary Disease Associated with Prolonged Opiate Use, Increased Short-Term Complications, and the Need for Revision Surgery following Total Knee Arthroplasty

Chronic obstructive pulmonary disease (COPD) is a condition which causes a substantial burden to patients, physicians, and the health care system at large. Medical comorbidities are commonly associated with adverse health outcomes in the postoperative period. Here, we present a large database review of patients undergoing total knee arthroplasty (TKA) to determine the effect of COPD on patient outcomes. The PearlDiver database was queried for all patients who underwent TKA between 2007 and the first quarter of 2017. Medical complications, surgical complications, 30-day readmission rates, revision rates, and opioid utilization were assessed at various intervals following TKA among patients with and without COPD. Multivariable regression was used to calculate adjusted odds ratios controlling for age, sex, and medical comorbidities. A total of 46,769 TKA patients with COPD and 120,177 TKA patients without COPD were studied. TKA patients with COPD experienced increased risk of 30-day readmission (40.8% vs. 32.2%, p < 0.0001), 30-day total medical complications (10.2% vs. 7.0%, p < 0.0001), prosthesis explanation at 6 months (0.4% vs. 0.2, p = 0.0130), 1 year (0.6% vs. 0.3%, p = 0.0005), and 2 years (0.8% vs. 0.5%, p = 0.0003), as well as an increased rate of revision (p < 0.0046) compared to TKA patients without COPD. Opioid utilization of TKA patients with COPD was greater significantly than that of TKA patients without COPD at 3, 6, and 12 months. Patients with COPD have an increased risk for medical and surgical complications, readmission, and prolonged opioid use following TKA.

Performance of the Cough and Sputum Assessment Questionnaire (CASA-Q) in COPD: Evidence from Clinical and Online Patient Interaction Studies

Introduction

Patient perception of the burden of chronic bronchitis symptoms in chronic obstructive pulmonary disease (COPD) can be assessed using patient-reported outcome measures (PROMs). The Cough and Sputum Assessment Questionnaire (CASA-Q) was developed and tested for this purpose. This study reviewed the performance of the CASA-Q in published online studies and tested a novel approach to complement traditional methods of qualitative content validation.

Methods

A targeted literature search was performed to identify published clinical studies of COPD using the CASA-Q as an endpoint. The performance of the questionnaire was examined in relation to other study endpoints, including clinical and functional measurements and other PROMs. Assessment of the content validity of the CASA-Q was carried out by comparing the content and structure of the questionnaire with published qualitative patient data from previously conducted online social media listening (SML) and online bulletin board (OBB) studies.

Results

In the interventional clinical trials, CASA-Q change scores were consistent with study objectives and other endpoints, including FEV1 and other PROMs. Two observational studies showed cross-sectional correlations with other PROMs like the St.-George's Respiratory Questionnaire (SGRQ) and COPD assessment test (CAT) scores. Qualitative data from the SML and OBB patient studies were consistent with the content and structure of the CASA-Q, supporting the content validity of the measure.

Conclusion

Results suggest that the CASA-Q is appropriately responsive to changes in cough and sputum symptoms and clinical impact in trials of COPD. The mapping of qualitative findings from online SML and OBB studies to CASA-Q domains and items confirm the content validity of the instrument. These results suggest the CASA-Q can be a valuable tool for evaluating treatment effect in COPD trials.

Flourishing despite Chronic Obstructive Pulmonary Disease (COPD): Findings from a Nationally Representative Survey of Canadians Aged 50 and Older

Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of mortality and is often associated with serious disability and depression. Little is known about the characteristics of those who are in complete mental health (CMH) despite having COPD. This study’s objectives are to: (1) estimate the prevalence and odds of absence of psychiatric disorders (APD) and CMH among older adults that reported having COPD, compared to their peers that did not; (2) identify factors associated with APD and with CMH. Bivariate and logistic regression analyses were conducted using the nationally representative Canadian Community Health Survey—Mental Health. The results indicate that there was a significantly (p < 0.001) lower prevalence of APD (86.7% vs. 95.0%) and CMH (66.7% vs. 77.0%) among older adults aged 50+ with COPD (n = 703) compared to those without COPD (n = 10,189). Half of the sample was female (50.5%) and the majority of whom were under age 70 (62.5%). Factors significantly (p < 0.05) associated with higher odds of APD and of CMH among older adults with COPD include being married, having a confidant, being physically active, and having no lifetime history of major depressive disorder or generalized anxiety disorder. For every additional adverse childhood experience, the odds of APD declined by 31%. The majority of those with COPD are mentally flourishing despite having this disabling and life-threatening disorder. These findings underline the importance of targeted interventions and outreach to those most vulnerable to poorer mental health outcomes including the socially isolated.

Exosomes derived from human umbilical cord mesenchymal stem cells protect against papain-induced emphysema by preventing apoptosis through activating VEGF-VEGFR2-mediated AKT and MEK/ERK pathways in rats

Introduction

Chronic obstructive pulmonary disease (COPD) is a leading cause of high mortality and heavy burden in the world. Unfortunately, emphysema, as an important component of COPD, has no curative treatments currently. Recently, human umbilical cord mesenchymal stem cells-derived exosomes (hUCMSC-Ex) constitute a promising alternative approach for tissue regeneration and repair. However, the roles of hUCMSC-Ex in emphysema and its mechanism are largely unknown. Here, we investigated the effect and the action mechanism of hUCMSC-Ex in repairing emphysema induced by papain in rats.

Methods

SD rats were used to establish a papain-induced emphysema model and estimate the effect and mechanism of hUCMSC-Ex treatment. H&E staining and mean linear intercept (MLI) were used to evaluate the hUCMSC-Ex effect on emphysema. Western blotting, TUNEL and miRNA-seq were used to investigate the molecular mechanisms of hUCMSC-Ex treatment in models of papain-induced emphysema.

Results

Papain treatment led to typical emphysema, while hUCMSC-Ex reversed emphysematous changes effectively. Apoptosis of endothelial cells and other types of cells were observed in models, while hUCMSC-Ex effectively prevented their apoptosis. hUCMSC-Ex repressed active caspase-3, activated VEGF-VEGFR2-mediated AKT pathway and MEK/ERK pathway in emphysematous lungs. Notably, several miRNAs, such as hsa-miR-10a-5p and hsa-miR-146a-5p, were target related to the roles of hUCMSC-Ex in papain-induced emphysema through VEGF-VEGFR2-mediated AKT and MEK/ERK pathways.

Conclusions

hUCMSC-Ex effectively rescued the papain-induced emphysema injury through VEGF-VEGFR2-mediated AKT pathway and MEK/ERK pathway.

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Exosomes from human umbilical cord mesenchymal stem cells (hUCMSC-Ex) pro protect against papain-injured emphysema in rats.

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hUCMSC-Ex prevent lung cells apoptosis by activating VEGF-VEGFR2-mediated AKT and MEK/ERK pathways.

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Several miRNAs, such as hsa-miR-10a-5p, were target related to the roles of hUCMSC-Ex.

Circadian clock gene Clock-Bmal1 regulates cellular senescence in Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disease. COPD is associated with accelerated lung aging. Circadian clock is believed to play important roles in COPD. Although the circadian molecular clock regulates cellular senescence, there is no information available regarding the impact of COPD. The aim of this study is to investigate the role of the circadian clock protein BMAL1 and CLOCK in cellular senescence in order to understand the cellular mechanisms of accelerated aging of COPD. Bmal1 and Clock levels were assessed in the plasma samples of non-smokers, smokers, and patients with COPD. The regulation of ciracadian clock expression and cell senescence by cigarette smoke extract (CSE) was studied in vitro, and small interfering RNA (siRNA) and overexpression of Bmal1 or Clock were employed to investigate the role of circadian clock on cell senescence. Herein, patients with COPD showed lower Bmal1 and Clock expression in the plasma. Interestingly, CSE exposure contributed to the increased cell senescence, decreased Clock and Bmal1 in human bronchial epithelial cells (Beas-2B cells). We found that knockdown of Clock or Bmal1 lead to upregulation of cell senescence in Beas-2B cells, while overexpression of Clock or Bmal1 inhibited cell senescence in Beas-2B cells, which is through the MAPK pathways. Therefore, our findings indicated that Bmal1 or Clock deficiency may be a significant factor to increase cellular senescence of the lung to develop COPD.

The Role of Long-Term Noninvasive Ventilation in Chronic Stable Hypercapnic Chronic Obstructive Pulmonary Disease

Despite the heterogeneity of data on the role of noninvasive ventilation (NIV) in severe stable chronic obstructive pulmonary disease with chronic hypercapnia, the current evidence supports the use of NIV in select populations and phenotypes. The Center for Medicare and Medicaid Services reimbursement criteria are complex, and the practice of navigating the most efficient method to initiate NIV therapy continues to be challenging. These patients optimally require referral to a medical center that has physicians with specific training in pulmonary and sleep medicine, who can navigate the specific needs for the use of NIV.

Thirty-Day Morbidity and Mortality in Patients With COPD Following Open Reduction and Internal Fixation for Rotational Ankle Fractures

Prior orthopedic literature has found patients with chronic obstructive pulmonary disease (COPD) to be at an increased risk for postoperative morbidity and mortality. Thus, the purpose of this study is to identify whether there are any differences in risk for 30-day morbidity or mortality following ORIF for ankle fractures between adult patients with COPD and without COPD. Patients undergoing operative treatment for ankle fracture were identified in the National Surgical Quality Improvement Program database from 2006 to 2018. Patients were divided into 2 cohorts: non-COPD and COPD patients. In this analysis, demographics data, medical comorbidities, and thirty-day postoperative outcomes were analyzed between the 2 cohorts. Bivariate and multivariate analyses were performed. Of 10,346 total patients who underwent operative treatment for ankle fracture, 9986 patients (96.5%) did not have a history of COPD whereas 360 (3.5%) had COPD. Following adjustment to control for demographic and comorbidity data, relative to patients without COPD, those with COPD had an increased risk of pneumonia (odds ratio [OR] 4.601; p = .001), unplanned intubation (OR 3.085; p = .043), and hospital readmission (OR 1.828; p = .020). Patients with COPD did not have a statistically significant difference with regards to mortality (OR 2.729; p = .080). Adult patients with COPD are at an increased risk for pneumonia, unplanned intubation, and hospital readmission within 30 days following ORIF of ankle fractures compared to patients without COPD. Despite these risks, this is a relatively safe procedure for these patients and the presence of COPD alone should not serve as a barrier to surgery.

Association between exposure to a mixture of metals, parabens, and phthalates and fractional exhaled nitric oxide: A population-based study in US adults

The effects of environmental endocrine-disrupting chemicals (EDCs) (e.g., phthalates) on fractional exhaled nitric oxide (FeNO) in children have received much attention. However, few studies evaluated this relationship in adults, and the previous studies have considered only a unitary exposure or a set of similar exposures instead of mixed exposures, which contain complicated interactions. We aimed to evaluate simultaneously the relationship between three types of EDCs (six phthalate metabolites and two parabens in urine, two heavy metals in blood) and FeNO (as a continuous variable) in adults. Data of adults aged ≥20 years from the National Health and Nutrition Examination Survey (NHANES, 2007-2012) were collected and analyzed. The generalized linear (GLM) regression model was used to explore the association of chemicals with FeNO. The combined effect of 10 chemicals on the overall association with FeNO was evaluated by the weighted quantile sum regression (WQS) model. In addition, The Bayesian kernel machine regression (BKMR) model was explored to investigate the interaction and joint effects of multiple chemicals with FeNO. Of the 3296 study participants ultimately included, among the GLMs, we found that mercury (Hg) (β = 0.84, 95%CI:0.32-1.36, FDR = 0.01) and methyl paraben (MPB) (β = 0.47, 95%CI:0.16-0.78, FDR = 0.015) were positively correlated with FeNO. In the WQS model, the combined effect of chemicals almost had a significantly positive association with FeNO and the top three contributors to the WQS index were Hg (40.2%), MECPP (22.1%), and MPB (19.3%). BKMR analysis showed that there may be interactions between MPB and Hg, Mono (carboxyoctyl) phthalate (MCOP) and Hg and the overall effect of the mixture showed a positive correlation with FeNO. In conclusion, our study strengthens the credibility of the view that EDCs can affect respiratory health. In the future, we should be particularly careful with products containing Hg, MECPP, MPB, and MEHP for the prevention of respiratory diseases.

Relationship between chronic obstructive pulmonary disease and cognition in an aging population

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is a common and severe respiratory illness. Prior research suggests that COPD may be associated with depression as well as cognitive impairment and increased risk of dementia. Many studies to date have been relatively small, have largely relied on global screening measures to identify cognitive impairment, and have not examined the potential role of comorbid depression on cognition. This cross-sectional study examined the relationship between COPD and multiple cognitive domains at two time points using data from a large longitudinal population database.

METHODS

Linear multivariate analyses were conducted using secondary data from the Wisconsin Longitudinal Study to determine the effect of lifetime COPD and depressive symptom severity, assessed with the Center for Epidemiological Studies Depression Scale (CESD), on multiple cognitive outcomes.

RESULTS

In both 2004 (n = 1608) and 2011 (n = 1743), lifetime COPD was found to be a non-significant predictor of all cognitive outcomes, while depressive symptom severity predicted significantly lower scores on the immediate recall and digit ordering tasks in 2004 and on all outcomes in 2011. Exploratory analyses in only those with lifetime COPD revealed COPD severity to be a non-significant factor for all outcomes in 2004 and 2011.

CONCLUSION

COPD was not significantly associated with cognition. Conversely, higher depressive symptom severity was significantly associated with poorer performance on additional cognitive tasks in 2011 compared to 2004, suggesting that depression may contribute to cognitive decline, dependent upon the context of aging.

Feasibility of a pulmonary rehabilitation programme for patients with symptomatic chronic obstructive pulmonary disease in Georgia: a single-site, randomised controlled trial from the Breathe Well Group

OBJECTIVES

To assess the feasibility of delivering a culturally tailored pulmonary rehabilitation (PR) programme and conducting a definitive randomised controlled trial (RCT).

DESIGN

A two-arm, randomised feasibility trial with a mixed-methods process evaluation.

SETTING

Secondary care setting in Georgia, Europe.

PARTICIPANTS

People with symptomatic spirometry-confirmed chronic obstructive pulmonary disease recruited from primary and secondary care.

INTERVENTIONS

Participants were randomised in a 1:1 ratio to a control group or intervention comprising 16 twice-weekly group PR sessions tailored to the Georgian setting.

PRIMARY AND SECONDARY OUTCOME MEASURES

Feasibility of the intervention and RCT were assessed according to: study recruitment, consent and follow-up, intervention fidelity, adherence and acceptability, using questionnaires and measurements at baseline, programme end and 6 months, and through qualitative interviews.

RESULTS

The study recruited 60 participants (as planned): 54 (90%) were male, 10 (17%) had a forced expiratory volume in 1 second of ≤50% predicted. The mean MRC Dyspnoea Score was 3.3 (SD 0.5), and mean St George's Respiratory Questionnaire (SGRQ) 50.9 (SD 17.6). The rehabilitation specialists delivered the PR with fidelity. Thirteen (43.0%) participants attended at least 75% of the 16 planned sessions. Participants and rehabilitation specialists in the qualitative interviews reported that the programme was acceptable, but dropout rates were high in participants who lived outside Tbilisi and had to travel large distances. Outcome data were collected on 63.3% participants at 8 weeks and 88.0% participants at 6 months. Mean change in SGRQ total was -24.9 (95% CI -40.3 to -9.6) at programme end and -4.4 (95% CI -12.3 to 3.4) at 6 months follow-up for the intervention group and -0.5 (95% CI -8.1 to 7.0) and -8.1 (95% CI -16.5 to 0.3) for the usual care group at programme end and 6 months, respectively.

CONCLUSIONS

It was feasible to deliver the tailored PR intervention. Approaches to improve uptake and adherence warrant further research.

TRIAL REGISTRATION NUMBER

ISRCTN16184185.