In South America, the rise in chronic respiratory diseases and weight-related issues due to the ongoing epidemiological transition has prompted research into their interrelationship.

Pulmonary diffusing capacity for nitric oxide (DLNO) remains underutilized despite potential advantages over pulmonary diffusing capacity for carbon monoxide (DLCO). We evaluated whether DLNO better detects emphysema than DLCO, spirometry, or lung volumes in smokers.

The incidence of infections caused by nontuberculous mycobacteria (NTM) are steadily increasing worldwide, and the most common site of infection is the lung. Clinical characteristics of individuals with NTM pulmonary disease (NTM-PD) demonstrate pronounced geographical heterogeneity. In the United States, NTM-PD has an affinity for postmenopausal White females, many of whom are never-smokers, whereas in Asia, NTM-PD is more common in males with post-tuberculosis lung disease. While these geographical differences are known on the global scale, it remains unclear whether radiographic sex-associated differences in NTM-PD are present within the U.S. cohort.

Patients with airflow limitation according to the fixed ratio but not the lower limit of normal (FR+LLN-) have a poorer respiratory prognosis and higher mortality than the normal fixed ratio. However, whether tiotropium treatment improves respiratory health outcomes in patients with FR+LLN- remains unclear.

Chronic obstructive pulmonary disease (COPD) is classified by its clinical phenotypes-chronic bronchitis and emphysema. A computed tomography (CT)-based mucus plug score (MPS) was recently identified as a biomarker to a subgroup of COPD patients with increased airway mucus plugs. While not necessarily linked to more pronounced symptoms or structural lung changes, mucus plugs are associated with increased mortality. Interestingly, a higher MPS seems to be associated with a lower body mass index (BMI), likewise associated with increased mortality. This study aims to characterize patients with advanced emphysema presenting for lung volume reduction therapy with a special focus on mucus plug occurrence.

The article "Metabolic Dysfunction-Associated Fatty Liver Disease in Chronic Obstructive Pulmonary Disease Patients: Insights From Vietnam" published in the July 2025 issue of Chronic Obstructive Pulmonary Diseases: Journal of the COPD Foundation ( JCOPDF) is significantly similar and in some sections, identical, to an article published in the January 2025 issue of the Vietnam Medical Journal. In December of 2024, Dr. Doan Le Minh Hanh, on behalf of all the above listed authors, claimed during the submission process to the JCOPDF that the manuscript had not been published or submitted elsewhere by answering this question affirmatively: "Confirm that the manuscript has been submitted solely to this journal and is not published, in press, or submitted elsewhere." In October 2025, Dr. Hanh notified the JCOPDF of the duplicate publication. As a result of this notification, we retract this article from the literature.

Eosinophilic chronic obstructive pulmonary disease (COPD) is a distinct subtype with clinical and biological differences from noneosinophilic COPD and asthma. Fractional exhaled nitric oxide (FeNO) is an established marker of type 2 airway inflammation in asthma, but its utility in eosinophilic COPD is less well understood. We analyzed baseline data from 176 participants in the Air Purification for Eosinophilic COPD Study, a randomized controlled trial of former smokers with eosinophilic COPD. At enrollment, FeNO and blood eosinophil counts were measured, and participants reported asthma history and severe COPD exacerbations requiring hospitalization in the prior year. Each 50cells/μL higher eosinophil count was associated with a 3.2% increase in FeNO (95% confidence interval [CI]: 0.3-6.1%). Asthma history was associated with a 29.1% higher FeNO (95% CI: 5.2-58.5%). Elevated FeNO, defined as ≥25 or ≥50 parts per billion, was linked to greater odds of an asthma diagnosis and a recent severe exacerbation, although CIs included the null. These findings suggest that FeNO may serve as a practical, noninvasive biomarker of type 2 inflammation in eosinophilic COPD and could help identify patients at higher risk of severe exacerbation.

Some studies suggest that statins could reduce the risk of chronic obstructive pulmonary disease (COPD), but it is unclear if this effect is related to their lipid-lowering properties. The causal link between serum lipid levels and COPD risk remains uncertain. This study aims to clarify this potential causal relationship and evaluate the impact of lipid-lowering drug target genes on COPD.

This meta-analysis assessed the effects of aerobic exercise on the function, prognosis, quality of life, and psychological outcome of patients with chronic obstructive pulmonary disease (COPD).

Chronic obstructive pulmonary disease (COPD) phenotyping is an approach for developing tailored therapies. The eosinophilic phenotype is associated with exacerbation risk and response to specific treatments. This study evaluates the relationship between sputum and blood eosinophilia, hypothesizing that sputum eosinophil percentage (SpE%) better reflects disease severity and exacerbation risk than blood eosinophil counts (BEC).

Chronic obstructive pulmonary disease (COPD) among individuals living in rural areas is associated with worse health outcomes. New strategies are needed to study interventions and deliver proven therapies to people with COPD in rural areas. This statement from the COPD Foundation Medical and Scientific Advisory Committee highlights specific challenges in capturing the key characteristics of rural residents and identifies approaches to improve research for COPD in rural areas. Specifically, geographic isolation, access to specialist care, lack of broadband access, and complex tobacco and exposure histories are drivers of COPD health disparities in rural populations that are not captured by conventional definitions of rurality. To improve the design of research studies among people with COPD living in rural settings, certain actions are identified. These include the inclusion of specific covariates such as distance and travel time to health care services and multidimensional assessment tools for societal and individual health determinants in data collection; deploying qualitative and mixed-methods research designs to assess cultural differences driving health care access and health behaviors; decentralized carousel recruitment models in study design; and operationalizing research partnerships to improve support for primary care providers engaged in research. These approaches will permit robust assessment of the complex matrices driving disparate health outcomes among people with COPD in rural areas.

Cathepsins, a family of lysosomal proteolytic enzymes, have been implicated in the pathogenesis of various complex diseases, including chronic obstructive pulmonary disease (COPD). However, the causal relationship between cathepsins and COPD remains unclear.

Pulmonary function tests may predict future outcomes; however, they are not often performed in middle-aged individuals at risk for future airway obstruction. We examined whether smokers with low lung function (LLF) have an increased risk of developing health problems and mortality over time.

This article does not contain an abstract.

A critical step in designing clinical trials to evaluate treatment efficacy in chronic obstructive pulmonary disease (COPD) is selecting fit-for-purpose outcome measures that reflect health concepts meaningful to people living with COPD. The purpose of this review was to summarize and synthesize qualitative literature addressing how patients with COPD describe aspects of their disease, to inform health concept selection and outcome measure selection.

Chronic lung diseases, including chronic obstructive pulmonary disease (COPD) and bronchiectasis (BE), may differ by sex in symptom onset, diagnostic delays, and disease burden. This study examined health care experiences and symptom burden among individuals with self-reported COPD, BE, or nontuberculous mycobacteria (NTM).

Chronic obstructive pulmonary disease (COPD) remains a challenging condition to manage due to its variability in clinical presentation and progression. While disease control is a well-defined concept in asthma, its relevance in COPD is less clear. This study aimed to evaluate the clinical utility of a COPD control framework, developed in Spain, in Portuguese outpatients by analyzing exacerbation rates among controlled and uncontrolled patients.

Chronic obstructive pulmonary disease (COPD) remains underdiagnosed and undertreated. Because screening asymptomatic individuals for COPD is not recommended, several case-finding tools have been explored. The COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE) questionnaire and peak expiratory flow (PEF) rate (CAPTURE tool) have been tested in the primary care setting, with disappointing results. We hypothesized that these tools could yield better results in a computed tomography lung screening (CTLS) program, where individuals have a history of cigarette smoking and higher prevalence of COPD.

Chronic obstructive pulmonary disease (COPD) is a global health challenge. Increasing numbers of patients with COPD are prescribed multiple medications (both for COPD and non-COPD disorders). This increases the risk of polypharmacy in these patients which can be linked with patient harm. However, the definition of polypharmacy is varied across literature (ranging from use of ≥3 to ≥20 medications). This review aims to report the prevalence of polypharmacy, report the varying definitions of polypharmacy, and report medication related harms amongst patients with COPD. We identified 28 studies reporting polypharmacy rates in COPD populations. A total of 13 studies (46.3%) defined polypharmacy as the use of ≥5 medications; however, the remaining studies had different definitions of polypharmacy. The available studies include multiple different countries and settings (primary care, secondary care, and community-based surveys). Polypharmacy and hyper polypharmacy (use of ≥10 medications) rates varied from 3.9% to 81.4% and 6.6% to 74.6% respectively. Polypharmacy in patients with COPD is common but poorly understood due to difficulty in comparing previous literature with differences in methodologies, patient populations, and definitions of polypharmacy. The multimorbid COPD population is likely at higher risk to the effects of polypharmacy through poor adherence, adverse drug reactions, and drug-drug interactions. Clinicians should be mindful of the patient's age, comorbidities, and drug-drug interactions while prescribing medications in the COPD clinic.

Chronic obstructive pulmonary disease (COPD) and asthma account for a significant health care burden within the United States. The asthma-COPD overlap (ACO) phenotype has been associated with increased exacerbation frequency and health care utilization compared to either disease alone. However, hospital-based outcomes of these diagnoses have not been described in the literature.

Metabolic dysfunction-associated fatty liver disease (MAFLD) affects approximately 38.7% of individuals globally and potentially leads to cirrhosis and hepatocellular carcinoma. This study aims to investigate the prevalence, characteristics, and impact of MAFLD on the frequency of exacerbations in chronic obstructive pulmonary disease (COPD) patients in Vietnam.