Phenotypic characterisation of early COPD: a prospective case-control study

Clinical characteristics and outcomes of chronic obstructive pulmonary disease patients with family history of chronic airway disease

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is a heterogeneous condition with different risk factors, including family history. This study aimed to explore association between a family history of chronic airway disease and features and outcomes of COPD.

METHODS

Participants were obtained from the RealDTC study between December 2016 and December 2022. Data on demographics, pulmonary function, history of exacerbation at baseline, acute exacerbation during 1-year follow-up and survival status during 3-years follow-up were collected.

RESULTS

5020 patients were enrolled, with 1307 patients (26.0%) having a family history of chronic airway diseases. Compared with patients without a family history of chronic airway diseases, patients with a family history had a lower forced expiratory Volume in one second (FEV1), higher Modified Medical Research Council (mMRC) score and COPD Assessment Test (CAT) score, higher rate of acute exacerbation and hospitalization in the past year (p < 0.05) and rate of acute exacerbation and hospitalization during 1 year follow-up period (p < 0.05). It was an independent risk factor for acute exacerbation (OR = 2.196; 95% CI =1.873-2.576) and hospitalization (OR = 2.199; 95% CI =1.812-2.670). Over 3 years of follow-up, there were no significant differences in mortality rates and annual changes in FEV1 between two groups.

CONCLUSION

COPD patients with a family history of chronic airway disease are not rare, and they tend to have more severe symptoms and a higher risk of future deterioration. In the management of COPD, special attention should be paid to patients with a family history of chronic airway disease.

Epidemiological trends and risk factors of chronic obstructive pulmonary disease in young individuals based on the 2021 global burden of disease data (1990-2021)

OBJECTIVE

Recent studies have shown that chronic obstructive pulmonary disease (COPD) in young individuals cannot be ignored. This study aims to investigate the burden of COPD and its associated risk factors in individuals aged 15 to 49 years, with a particular focus on health inequities across different levels of socioeconomic development.

METHODS

By analyzing data from the Global Burden of Disease (GBD) 2021, we utilized statistical methods such as Joinpoint regression, frontier analysis, and health inequality analysis to evaluate the changes in the age-standardized disability-adjusted life year (DALY) rates (ASDR) and incidence rates (ASIR) of COPD among the global population aged 15-49 years from 1990 to 2021. We specifically examined the disparities in health across countries and regions with varying levels of socioeconomic development. Key risk factors, including particulate matter pollution, smoking, and occupational exposure, were analyzed.

RESULTS

The number of COPD cases among young people globally has significantly increased.While the global ASDR and ASIR of COPD in the 15-49 age group showed an overall declining trend, the burden of COPD remained high in low Sociodemographic Index (SDI) regions and there were significant health inequalities between countries. Particulate matter pollution (41.79%), smoking (19.81%), and occupational exposure (11.73%) were identified as the primary contributors to the burden of COPD in younger individuals. In low SDI regions, particulate matter pollution had a particularly significant impact, accounting for 58.65% of attributable proportion of DALYs, and remained at a persistently high level. Smoking continued to contribute significantly to the burden of COPD in high-income regions, notably in North America, where smoking accounted for 34.26% of DALYs in 2021.

CONCLUSION

Although there is a global downward trend in the burden of COPD among young people, significant health inequities persist in low SDI regions. The findings emphasize the need for more effective public health activities targeting younger populations and low SDI countries and regions, particularly in improving air quality, reducing smoking, and mitigating occupational exposures.

CLINICAL TRIAL NUMBER

Not applicable.

Contrasting the clinical and biological characteristics of young and old COPD patients

Background

The ECLIPSE study was a large, international, prospective, controlled, observational study that included COPD patients (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 2-4), as well as smoking and non-smoking participants with normal spirometry, aged 40-75 years, who were followed-up regularly for 3 years. Here we sought to contrast the clinical and biological characteristics of young COPD versus controls of similar age and older COPD patients included in ECLIPSE.

Methods

We compared 106 young (<50 years) and 488 old (>70 years) COPD patients, as well as 119 young smokers and 92 nonsmoker controls (<50 years) with normal spirometry.

Results

Young COPD patients: 1) were more symptomatic than young controls, often reported a family history of chronic bronchitis, emphysema and asthma, as well as a personal history of asthma and bronchitis, and suffered from a similar disease burden to older patients; 2) were at higher risk of substantial forced expiratory volume in 1 s decline over time; and 3) had reduced serum levels of CC16 (a lung-derived anti-inflammatory protein that relates to lung damage) and, at the same time, reduced pro-inflammatory markers compared to older COPD patients.

Conclusions

Young COPD patients suffer from significant disease burden, display an altered biomarker and disease progression profile reflected by an accelerated risk of lung function decline highlighting the need for early life diagnosis, prevention approaches and treatment.

Clinical Characteristics of Chronic Obstructive Pulmonary Disease according to Smoking Status

Chronic obstructive pulmonary disease (COPD) can be caused by various factors, including lung infections, asthma, air pollution, childhood growth disorders, and genetic factors, though smoking is the predominant risk factor. The main pathological mechanisms in COPD involve small airway disease, emphysema, mucus hypersecretion, and vascular disorders. COPD in non-smokers is characterized by a normal 1-second forced expiratory volume decline, equal sex distribution, younger age of onset, fewer comorbidities, milder airflow obstruction, preserved diffusing capacity of the lungs for carbon monoxide, and radiological features such as more air-trapping and less severe emphysema compared to COPD in smokers. Nevertheless, non-smokers with COPD still experience a high prevalence of acute exacerbations, nearly equal to that of smokers with COPD. Moreover, COPD itself is an independent risk factor for developing lung cancer, regardless of smoking status. Given that COPD coexists with numerous comorbidities, effectively managing these comorbidities is crucial, requiring multifaceted efforts for comprehensive treatment.

Association between birth weight and chronic obstructive pulmonary disease in the UK Biobank: a prospective cohort study

BACKGROUND

Birth weight has been reported to be associated with chronic obstructive pulmonary disease (COPD) in adulthood, but the results have not yet been determined. This study aims to analyse the potential association of birth weight with COPD risk in UK Biobank.

METHODS

We conducted a prospective analysis for participants without baseline COPD in UK Biobank. The HRs and 95% CIs were calculated by multivariable Cox regression models, and dose-response relationship was evaluated by restricted cubic splines. Besides, we also calculated the interactions for covariates and further analysed the joint effects.

RESULTS

A total of 251 172 participants with birth weight data were included in this study, and 5602 COPD cases were found during follow-up. According to Cox regression models, participants with the lowest quintile of birth weight (< 2.86 kg) had higher risk for COPD (HR=1.21, 95% CI 1.11 to 1.32). In addition, the dose‒response analysis showed a non-linear relationship between birth weight and COPD risk, which first decreased and then increased, and the interactions for age, passive smoking and maternal smoking were also found by stratified analysis. Furthermore, we also found the joint effects between COPD risk and maternal smoking in the lowest quintile group.

CONCLUSIONS

This study indicated that lower birth weight may increase the risk of COPD. The non-linear associations between birth weight and COPD risk for prospective cohort; as birth weight increased, the risk showed a trend of decreasing first and then increasing. Moreover, maternal smoking had a joint effect with low birth weight for COPD risk.

Comprehensive appraisal of lung function in young COPD patients: a single center observational study

PURPOSE

The present study aimed to investigate the clinical characteristics and lung function impairment in young people diagnosed with chronic obstructive pulmonary disease (COPD).

PATIENTS AND METHODS

We retrospectively enrolled patients with COPD who underwent symptom assessment and comprehensive pulmonary function tests at the First Affiliated Hospital of Guangzhou Medical University between August 2017 and March 2022. The patients were categorized into two groups based on age: a young COPD group (aged 20-50 years) and an old COPD group (aged > 50 years).

RESULTS

A total of 1282 patients with COPD were included in the study, with 76 young COPD patients and 1206 old COPD patients. Young COPD patients exhibited a higher likelihood of being asymptomatic, lower rates of smoking, and a lower smoking index compared to old COPD patients. Although young COPD patients had higher median post-bronchodilator forced expiratory volume in 1 s (post-BD FEV1) (1.4 vs.1.2 L, P = 0.019), diffusing capacity of the lung for carbon monoxide (DLCO) (7.2 vs. 4.6, P<0.001), and a lower median residual volume to total lung capacity ratio (RV/TLC) compared to their older counterparts, there were no differences observed in severity distribution by GOLD categories or the proportion of lung hyperinflation (RV/TLC%pred > 120%) between two groups. Surprisingly, the prevalence of reduced DLCO was found to be 71.1% in young COPD, although lower than in old COPD (85.2%).

CONCLUSION

Young COPD showed fewer respiratory symptoms, yet displayed a similar severity distribution by GOLD categories. Furthermore, a majority of them demonstrated lung hyperinflation and reduced DLCO. These results underscore the importance of a comprehensive assessment of lung function in young COPD patients.

Risk factors of acute exacerbation and disease progression in young patients with COPD

OBJECTIVE

We aimed to elucidate the clinical factors associated with acute exacerbation and disease progression in young patients with chronic obstructive pulmonary disease (COPD).

METHODS

This retrospective longitudinal observational study included patients with COPD aged between 20 and 50 years with post-bronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC)<0.7. Eligible patients were followed up with ≥2 spirometry examinations at 1 year interval after COPD diagnosis. The primary outcome was moderate-to-severe acute exacerbation in young patients with COPD. Secondary outcomes were early initiation of regular inhalation therapy and accelerated annual post-bronchodilator FEV1 decline.

RESULTS

A total of 342 patients were followed up during a median of 64 months. In multivariable analyses, risk factors for moderate-to-severe exacerbation were history of asthma (adjusted HR (aHR)=2.999, 95% CI=[2.074-4.335]), emphysema (aHR=1.951, 95% CI=[1.331-2.960]), blood eosinophil count >300/µL (aHR=1.469, 95% CI=[1.038-2.081]) and low FEV1 (%) (aHR=0.979, 95% CI=[0.970-0.987]). A history of asthma, sputum, blood eosinophil count >300/µL, low FEV1 (%) and low diffusing capacity of the lung for carbon monoxide (DLCO) (%) were identified as clinical factors associated with the early initiation of regular inhalation therapy. The risk factors associated with worsened FEV1 decline were increasing age, female sex, history of pulmonary tuberculosis, sputum, low FEV1 (%) and low DLCO (%).

CONCLUSIONS

In young COPD patients, specific high-risk features of acute exacerbation and disease progression need to be identified, including a history of previous respiratory diseases, current respiratory symptoms, blood eosinophil counts, and structural or functional pulmonary impairment.

Use of human airway smooth muscle in vitro and ex vivo to investigate drugs for the treatment of chronic obstructive respiratory disorders

Isolated airway smooth muscle has been extensively investigated since 1840 to understand the pharmacology of airway diseases. There has often been poor predictability from murine experiments to drugs evaluated in patients with asthma or chronic obstructive pulmonary disease (COPD). However, the use of isolated human airways represents a sensible strategy to optimise the development of innovative molecules for the treatment of respiratory diseases. This review aims to provide updated evidence on the current uses of isolated human airways in validated in vitro methods to investigate drugs in development for the treatment of chronic obstructive respiratory disorders. This review also provides historical notes on the pioneering pharmacological research on isolated human airway tissues, the key differences between human and animal airways, as well as the pivotal differences between human medium bronchi and small airways. Experiments carried out with isolated human bronchial tissues in vitro and ex vivo replicate many of the main anatomical, pathophysiological, mechanical and immunological characteristics of patients with asthma or COPD. In vitro models of asthma and COPD using isolated human airways can provide information that is directly translatable into humans with obstructive lung diseases. Regardless of the technique used to investigate drugs for the treatment of chronic obstructive respiratory disorders (i.e., isolated organ bath systems, videomicroscopy and wire myography), the most limiting factors to produce high-quality and repeatable data remain closely tied to the manual skills of the researcher conducting experiments and the availability of suitable tissue.

Update on metabolomic findings in COPD patients

COPD is a heterogeneous disorder that shows diverse clinical presentations (phenotypes and "treatable traits") and biological mechanisms (endotypes). This heterogeneity implies that to carry out a more personalised clinical management, it is necessary to classify each patient accurately. With this objective, and in addition to clinical features, it would be very useful to have well-defined biological markers. The search for these markers may either be done through more conventional laboratory and hypothesis-driven techniques or relatively blind high-throughput methods, with the omics approaches being suitable for the latter. Metabolomics is the science that studies biological processes through their metabolites, using various techniques such as gas and liquid chromatography, mass spectrometry and nuclear magnetic resonance. The most relevant metabolomics studies carried out in COPD highlight the importance of metabolites involved in pathways directly related to proteins (peptides and amino acids), nucleic acids (nitrogenous bases and nucleosides), and lipids and their derivatives (especially fatty acids, phospholipids, ceramides and eicosanoids). These findings indicate the relevance of inflammatory-immune processes, oxidative stress, increased catabolism and alterations in the energy production. However, some specific findings have also been reported for different COPD phenotypes, demographic characteristics of the patients, disease progression profiles, exacerbations, systemic manifestations and even diverse treatments. Unfortunately, the studies carried out to date have some limitations and shortcomings and there is still a need to define clear metabolomic profiles with clinical utility for the management of COPD and its implicit heterogeneity.

Exploring Current Concepts and Challenges in the Identification and Management of Early-Stage COPD

The need to improve health outcomes, as well as disease prognosis, has led clinicians and researchers to propose new ways of identifying COPD in its earliest forms. This initiative is based on the hypothesis that an earlier intervention would have a greater prognostic impact. However, the operational definition of a patient in the initial stages of the disease is complex, and there is still no unanimously accepted definition. GOLD has recently proposed different concepts to identify COPD in its early stages, such as COPD in young people or COPD with mild functional impairment. In addition, GOLD proposes two other concepts, called pre-COPD (symptomatic non-obstructive patients) and PRISm (preserved ratio with impaired spirometry), which aim to identify the patient at risk of developing this chronic airflow obstruction. However, despite the attractiveness of these concepts, none have been taken up universally by the medical community. A universally accepted identification of how to define COPD in its early stages is necessary as a preliminary step in order to design clinical trials to find out the best way to treat these patients. This review deals with these concepts of COPD at the onset of the disease, highlighting their importance and the problems involved in identifying them as therapeutic targets in real clinical practice.

Current Progress of COPD Early Detection: Key Points and Novel Strategies

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide, with approximately 70% to 80% of adults with COPD being undiagnosed. Patients with undiagnosed COPD are at increased risk of poor outcomes and a worsened quality of life, making early detection a crucial strategy to mitigate the impact of COPD and reduce the burden on healthcare systems. In the past decade, increased interest has been focused on the development of effective strategies and instrument for COPD early detection. However, identifying undiagnosed cases of COPD is still challenging. Both screening and case-finding approaches have been adopted to identify undiagnosed COPD, with case-finding being recommended by the 2023 Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline and the updated United States Preventive Services Task Force (USPTF) recommendation. Nonetheless, the approaches, criteria, and instruments used for early detection of COPD are varied. However, advances in the taxonomy and risk factors of COPD are continuously being investigated. It is important to continuously assess the current state of knowledge on COPD early detection, given the challenges associated with identifying undiagnosed COPD. This review aims to highlight recent advances in early detection of COPD. To discuss the current challenge and opportunity in COPD early detection, providing an overview of existing literature on COPD case-finding strategies, including the approaches, criteria for subjects, and instruments. The review also summarizes the current progress in COPD case-findings and proposes a COPD case-finding flowchart as an efficient method for identifying at risk COPD patients.

Prevalence, risk factors, and mortality of COPD in young people in the USA: results from a population-based retrospective cohort

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has been considered a disease of the elderly, but it could also occur in young people aged 20-50 years. However, the characteristics and prognosis of COPD in such young people remain unclear.

METHODS

Our retrospective cohort study was based on the National Health and Nutrition Examination Survey (NHANES). Participants who 20-50 years old at baseline and completed the pulmonary function test were enrolled in our study cohort. These participants were followed up to 31 December 2019. The sample weight and Taylor Linearization Procedures were adapted to make representative estimations of prevalence and baseline characteristics. The weighted logistic regression model was used to assess the risk factors. The propensity score method and Cox proportional hazard models were applied to calculate the risk of mortality.

RESULTS

The weighted prevalence of COPD in young people in the USA was 1.64% and it increased with age, with a higher prevalence in males than females (2.59% vs 0.72%, p<0.001). The proportion of Global Initiative for COPD 1-2 was 96.7%. Males (OR=4.56, 95% CI: 2.74 to 7.61), non-Hispanic black (OR=2.77; 95% CI: 1.14 to 6.75), non-Hispanic white (OR=4.93; 95% CI: 2.16 to 11.28) and smoking (current smoking, OR=2.36; 95% CI: 1.40 to 3.98; ever smoking, OR=1.92; 95% CI: 1.05 to 3.51; passive smoking, OR=2.12; 95% CI: 1.41 to 3.20) were shown to be independent risk factors for COPD in young people. Compared with those matched by sex, age and race, the young people with COPD had a higher risk of all-cause death (HR=3.314, p<0.001).

CONCLUSION

COPD in young people has a low prevalence in the USA and its independent risk factors included male, race (non-Hispanic black and non-Hispanic white) and smoking. Young COPD has a higher risk of all-cause mortality than the matched non-COPD.

Global prevalence of malnutrition in patients with chronic obstructive pulmonary disease: Systemic review and meta-analysis

BACKGROUND

Malnutrition is a significant comorbidity among chronic obstructive pulmonary disease (COPD), but it has been often ignored. To date, the prevalence of malnutrition and its association with clinical parameters in the patients with COPD have not been well described. We aimed to investigate the prevalence of malnutrition and the prevalence of at-risk for malnutrition among COPD and the clinical impact of malnutrition on patients with COPD in a systematic review and meta-analysis.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were searched for articles describing the prevalence of malnutrition and/or at-risk for malnutrition from January 2010 to December 2021. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. Meta-analyses were performed to determine the prevalence of malnutrition and at-risk for malnutrition and the clinical impact of malnutrition on patients with COPD. Meta-regression and subgroup analyses were performed to explore the sources of heterogeneity. Comparisons were made between individuals with and without malnutrition according to pulmonary function, degree of dyspnea, exercise capacity, and mortality risk.

RESULTS

Out of the 4156 references identified, 101 were read full-text, of which 36 studies were included. The total number of involved patients included in this meta-analysis was 5289. The prevalence of malnutrition was 30.0% (95% CI 20.3 to 40.6), compared with an at-risk prevalence of 50.0% (95% CI 40.8 to 59.2). Both prevalences were associated with regions and measurement tools. The prevalence of malnutrition was associated with COPD phase (acute exacerbations and stable). COPD with malnutrition showed lower forced expiratory volume 1 s % predicted (mean difference (MD) -7.19, 95% CI -11.86 to -2.52), higher modified Medical Research Council dyspnea scores (MD 0.38, 95% CI 0.12 to 0.64), poorer exercise tolerance (standardized mean difference -0.29, 95% CI -0.54 to -0.05), and higher mortality risk (hazard ratio 2.24, 95% CI 1.23 to 4.06) compared to COPD without malnutrition.

CONCLUSION

Malnutrition and at-risk for malnutrition are common among COPD. Malnutrition negatively impacts important clinical outcomes of COPD.

Unravelling young COPD and pre-COPD in the general population

Background

Chronic obstructive pulmonary disease (COPD) is commonly diagnosed when the airflow limitation is well established and symptomatic. We aimed to identify individuals at risk of developing COPD according to the concept of pre-COPD and compare their clinical characteristics with 1) those who have developed the disease at a young age, and 2) the overall population with and without COPD.

Methods

The EPISCAN II study is a cross-sectional, population-based study that aims to investigate the prevalence of COPD in Spain in subjects ≥40 years of age. Pre-COPD was defined as the presence of emphysema >5% and/or bronchial thickening by computed chromatography (CT) scan and/or diffusing capacity of the lung for carbon monoxide (D _LCO) <80% of predicted in subjects with respiratory symptoms and post-bronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) >0.70. Young COPD was defined as FEV₁/FVC <0.70 in a subject ≤50 years of age. Demographic and clinical characteristics were compared among pre-COPD, young COPD and the overall population with and without COPD.

Results

Among the 1077 individuals with FEV₁/FVC <0.70, 65 (6.0%) were ≤50 years of age. Among the 8015 individuals with FEV₁/FVC >0.70, 350 underwent both D _LCO testing and chest CT scanning. Of those, 78 (22.3%) subjects fulfilled the definition of pre-COPD. Subjects with pre-COPD were older, predominantly women, less frequently active or ex-smokers, with less frequent previous diagnosis of asthma but with higher symptomatic burden than those with young COPD.

Conclusions

22.3% of the studied population was at risk of developing COPD, with similar symptomatic and structural changes to those with well-established disease without airflow obstruction. This COPD at-risk population is different from those that develop COPD at a young age.

Prognostic value of lymphocyte count for in-hospital mortality in patients with severe AECOPD

Background

Patients with severe acute exacerbations of chronic obstructive pulmonary disease often have a poor prognosis. Biomarkers can help clinicians personalize the assessment of different patients and mitigate mortality. The present study sought to determine if the lymphocyte count could act as a risk factor for mortality in individuals with severe AECOPD.

Methods

A retrospective study was carried out with 458 cases who had severe AECOPD. For analysis, patients were divided into two groups on the basis of lymphocyte count: < 0.8 × 10⁹/L and ≥ 0.8 × 10⁹/L.

Results

Patients who fulfilled the criteria for inclusion were enrolled, namely 458 with a mean age of 78.2 ± 8.2 years. Of these patients, 175 had a low lymphocyte count. Compared to patients with normal lymphocyte counts, those with low counts were older (79.2 ± 7.4 vs. 77.5 ± 8.6 years, p = 0.036), had lower activities of daily living scores on admission (35.9 ± 27.6 vs. 47.5 ± 17.1, p < 0.001), and had a greater need for home oxygen therapy (84.6 vs. 72.1%, p = 0.002). Patients with low lymphocytes had higher mortality rates during hospitalization (17.1 vs. 7.1%, p = 0.001), longer hospital stay (median [IQR] 16 days [12–26] vs. 14 days [10–20], p = 0.002) and longer time on mechanical ventilation (median [IQR] 11.6 days [5.8–18.7] vs. 10.9 days [3.8–11.6], p < 0.001). The logistic regression analysis showed lymphocyte count < 0.8 × 10⁹/L was an independent risk factor associated with in-hospital mortality (OR 2.74, 95%CI 1.33–5.66, p = 0.006).

Conclusion

Lymphocyte count could act as a predictor of mortality in patients with severe AECOPD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02137-1.

Comorbidities and mortality risk in adults younger than 50 years of age with chronic obstructive pulmonary disease

Rationale and objective

Patients with chronic obstructive pulmonary disease (COPD), usually diagnosed after the 6th decade, frequently suffer from comorbidities. Whether COPD patients 50 years or younger (Young COPD) have similar comorbidities with the same frequency and mortality impact as aged-matched controls or older COPD patients is unknown.

Methods

We compared comorbidity number, prevalence and type in 3 groups of individuals with ≥ 10 pack-years of smoking: A Young (≤ 50 years) COPD group (n = 160), an age-balanced control group without airflow obstruction (n = 125), and Old (> 50 years) COPD group (n = 1860). We also compared survival between the young COPD and control subjects. Using Cox proportional model, we determined the comorbidities associated with mortality risk and generated Comorbidomes for the “Young” and “Old” COPD groups.

Results

The severity distribution by GOLD spirometric stages and BODE quartiles were similar between Young and Old COPD groups. After adjusting for age, sex, and pack-years, the prevalence of subjects with at least one comorbidity was 31% for controls, 77% for the Young, and 86% for older COPD patients. Compared to controls, “Young” COPDs’ had a nine-fold increased mortality risk (p < 0.0001). “Comorbidomes” differed between Young and Old COPD groups, with tuberculosis, substance use, and bipolar disorders being distinct comorbidities associated with increased mortality risk in the Young COPD group.

Conclusions

Young COPD patients carry a higher comorbidity prevalence and mortality risk compared to non-obstructed control subjects. Young COPD differed from older COPD patients by the behavioral-related comorbidities that increase their risk of premature death.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02191-7.

Parental COPD as a Risk Factor for the Development of COPD and Disease Severity in Offspring: A Systematic Scoping Review

Background

There is sparse literature on parental chronic obstructive pulmonary disease (COPD) as a risk factor for the development of COPD in adult offspring, and the impact on disease severity. We aimed to map the literature reporting on the prevalence of and/or association between parental COPD and COPD in offspring, and to evaluate whether or not the literature reports on the severity of COPD or other health-related outcomes in offspring with parental COPD.

Methods

A systematic literature search in Embase and Ovid MEDLINE was performed in June 2021. Search terms revolved around COPD and predisposition.

Results

Thirteen studies were identified: 10 case-control studies, two cross-sectional studies and one cohort study. Population size varied from 44 to 2668 offspring cases; the distribution of female cases varied from 5% to 80% and mean age ranged from 27 to 65. Nine studies used an antecedents approach and evaluated the prevalence of parental COPD in patients with COPD, which ranged from 19% to 58%. Four studies used a descendants approach, by identifying patients with COPD and subsequently evaluated prevalence of COPD in their offspring, and found a prevalence of 0% to 17%. Apart from one, all the studies found an increased odds ratio for COPD in individuals with parental COPD. Four studies reported on parental smoking history and nine studies reported on smoking history in offspring. Three studies evaluated the association between parental COPD and COPD-related outcomes in patients with COPD.

Conclusion

This review indicates that parental COPD is associated with a higher risk of COPD in offspring. The literature is sparse, and we identified a knowledge gap on whether parental COPD is a risk factor for severe COPD and other health conditions in offspring.

Strain Analysis in Patients at High-Risk for COPD Using Four-Dimensional Dynamic-Ventilation CT

Purpose

To quantitatively identify abnormal lung motion in chronic obstructive pulmonary disease (COPD) using strain analysis, and further clarify the potential differences of deformation in COPD with different severity of airflow limitation.

Materials and Methods

Totally, 53 patients at high-risk for COPD were enrolled in this study. All CT examinations were performed on a 320-row MDCT scanner, and strain measurement based on dynamic-ventilation CT data was performed with a computational fluid dynamics analysis software (Micro Vec V3.6.2). The strain-related parameters derived from the whole expiration phase (PSmax-all, PSmean-all, Speedmax-all ), the first 2s of expiration phase (PSmax2s, PSmean2s, Speedmax2s ) were divided respectively by the changes in lung volume to adjust for the degree of expiration. Spearman rank correlation analysis was used to evaluate associations between the strain-related parameters and various spirometric parameters. Comparisons of the strain-related parameters between COPD and non-COPD patients, between GOLD I (mild airflow restriction) and GOLD II-IV (moderate to severe airflow restriction) were made using the Mann-Whitney U-test. Receiver-operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of the strain-related parameters for COPD. P <0.05 was considered statistically significant.

Results

Strain-related parameters demonstrated positive correlations with spirometric parameters (ρ=0.275~0.687, P<0.05), suggesting that heterogeneity in lung motion was related to abnormal spirometric results. Strain-related parameters can quantitatively distinguish COPD from non-COPD patients with moderate diagnostic significance with the AUC values ranged from 0.821 to 0.894. Furthermore, parameters of the whole expiration phase (PSmax-all, Speedmax-all) demonstrated significant differences (P=0.005; P=0.04) between COPD patients with mild and moderate to severe airflow limitation.

Conclusion

Strain-related parameters derived from dynamic-ventilation CT data covering the whole lung associated with lung function changes in COPD, reflecting the severity of airflow limitation in some degree, even though its utility in severe COPD patients remains to be investigated.

Prevalence and Population Attributable Risk for Early Chronic Obstructive Pulmonary Disease in U.S. Hispanic/Latino Individuals

Rationale: In predominantly White populations, early chronic obstructive pulmonary disease (COPD) (i.e., COPD in people aged <50 yr) has been linked to higher hospitalization rates and mortality; however, the prevalence, risk factors, and population attributable risk (PAR) of early COPD remain to be determined in non-White populations. Objectives: We aimed to examine the prevalence, risk factors, and PARs of early COPD among Hispanic/Latino individuals, the largest U.S. minority group. Methods: We used baseline data from the Hispanic Community Health Study/Study of Latinos, a population-based probability sample of 16,415 Hispanic/Latino individuals aged 18-74 years. Participants aged <50 years were included (N = 7,323). Early COPD was defined as a forced expiratory volume in 1 second to forced vital capacity ratio less than the lower limit of normal. We used survey logistic regression analysis to identify risk factors and estimate the prevalence of early COPD. PARs of the risk factors identified were estimated. Results: A total of 524 participants met the criteria for early COPD, yielding a sex- and age-adjusted prevalence of 7.6% (95% confidence interval [CI], 6.8-8.6). Asthma (odds ratio [OR], 3.37; 95% CI, 2.57-4.41), smoking status (ever vs. never; OR, 1.65; 95% CI, 1.24-2.20), and chronic sinusitis (OR, 1.71; 95% CI, 1.09-2.66) were associated with increased odds of early COPD. Immigrants versus U.S.-born individuals have lower odds of early COPD (age at immigration <15 yr and living in the United States <10 yr; OR, 0.94; 95% CI, 0.39-2.27; age at immigration <15 yr and living in the United States ⩾10 yr; OR, 0.55; 95% CI, 0.37-0.84; age at immigration ⩾15 yr and living in the United States <10 yr; OR, 0.86; 95% CI, 0.57-1.30; and age at immigration ⩾15 yr and living in the United States ⩾10 yr; OR, 0.63; 95% CI, 0.42-0.95). Among smokers, pack-years was not associated with early COPD (5-9.9 vs. <5 pack-years; OR, 1.04; 95% CI, 0.59-1.82; ⩾10 vs. <5 pack-years; OR, 1.20; 95% CI, 0.74-1.94). The mean PAR for asthma, smoking status, and chronic sinusitis was 26.3% (95% CI, 22.1-30.3), 22.4% (95% CI, 17.4-27.1), and 6.9% (95% CI, 4.3-9.4), respectively. Conclusions: Among U.S. Hispanic/Latino individuals, asthma is one of the most important risk factors for early COPD, followed by smoking and chronic sinusitis. Immigrants appear to have a lower risk of early COPD than U.S.-born Hispanic/Latino individuals.

Treatment Trials in Young Patients with Chronic Obstructive Pulmonary Disease and Pre-Chronic Obstructive Pulmonary Disease Patients: Time to Move Forward

Chronic obstructive pulmonary disease (COPD) is the end result of a series of dynamic and cumulative gene-environment interactions over a lifetime. The evolving understanding of COPD biology provides novel opportunities for prevention, early diagnosis, and intervention. To advance these concepts, we propose therapeutic trials in two major groups of subjects: "young" individuals with COPD and those with pre-COPD. Given that lungs grow to about 20 years of age and begin to age at approximately 50 years, we consider "young" patients with COPD those patients in the age range of 20-50 years. Pre-COPD relates to individuals of any age who have respiratory symptoms with or without structural and/or functional abnormalities, in the absence of airflow limitation, and who may develop persistent airflow limitation over time. We exclude from the current discussion infants and adolescents because of their unique physiological context and COPD in older adults given their representation in prior randomized controlled trials (RCTs). We highlight the need of RCTs focused on COPD in young patients or pre-COPD to reduce disease progression, providing innovative approaches to identifying and engaging potential study subjects. We detail approaches to RCT design, including potential outcomes such as lung function, patient-reported outcomes, exacerbations, lung imaging, mortality, and composite endpoints. We critically review study design components such as statistical powering and analysis, duration of study treatment, and formats to trial structure, including platform, basket, and umbrella trials. We provide a call to action for treatment RCTs in 1) young adults with COPD and 2) those with pre-COPD at any age.

Telomere Length but Not Mitochondrial DNA Copy Number Is Altered in Both Young and Old COPD

Accelerated ageing is implicated in the pathogenesis of respiratory diseases as chronic obstructive pulmonary disease (COPD), but recent evidence indicates that the COPD can have roots early in life. Here we hypothesise that the accelerated ageing markers might have a role in the pathobiology of young COPD. The objective of this study was to compare two hallmarks of ageing, telomere length (TL), and mitochondrial DNA copy number (mtDNA-CN, as a surrogate marker of mitochondrial dysfunction) in young (≤ 50 years) and old (>50 years) smokers, with and without COPD. Both, TL and mtDNA-CN were measured in whole blood DNA by quantitative PCR [qPCR] in: (1) young ever smokers with (n = 81) or without (n = 166) COPD; and (2) old ever smokers with (n = 159) or without (n = 29) COPD. A multivariable linear regression was used to assess the association of TL and mtDNA-CN with lung function. We observed that in the entire study population, TL and mtDNA-CN decreased with age, and the former but not the latter related to FEV₁/FVC (%), FEV₁ (% ref.), and DLCO (% ref.). The short telomeres were found both in the young and old patients with severe COPD (FEV₁ <50% ref.). In addition, we found that TL and mtDNA-CN were significantly correlated, but their relationship was positive in younger while negative in the older patients with COPD, suggesting a mitochondrial dysfunction. We conclude that TL, but not mtDNA-CN, is associated with the lung function impairment. Both young and old patients with severe COPD have evidence of accelerated ageing (shorter TL) but differ in the direction of the correlation between TL and mtDNA-CN in relation to age.

Impact of early life exposures on COPD in adulthood: A systematic review and meta-analysis

Early life represents a critical period for the development and growth of the lungs. Adverse exposures in this stage may drive the development of chronic obstructive pulmonary disease (COPD). Thus, we quantitatively evaluated the impact of different early life exposures on COPD in adulthood. The PubMed, Embase and Cochrane Library electronic databases were searched for articles published from January 2001 to October 2020. A total of 30 studies (795,935 participants) met the criteria and were included in the review. We found a significant association of COPD with childhood serious respiratory infections, pneumonia or bronchitis (pooled adjusted OR [aOR], 2.23 [95% CI, 1.63-3.07]). The probability of COPD was increased 3.45-fold for children with than without asthma (pooled aOR, 3.45 [95% CI, 2.37-5.02]). In addition, the probability of COPD was associated with maternal smoking (pooled aOR, 1.42 [95% CI, 1.17-1.72]), any child maltreatment (pooled aOR, 1.30 [95% CI, 1.18-1.42]) and low birth weight (pooled aOR, 1.58 [95% CI, 1.08-2.32]) but not childhood environmental tobacco smoke exposure (pooled aOR, 1.15 [0.83-1.61]) or premature birth (pooled aOR, 1.17 [95% CI, 0.87-1.58]). Furthermore, subgroup analyses revealed that probability was increased for only women with childhood physical abuse, sexual abuse and exposure to intimate partner violence. Factors resulting in COPD in adults could trace back to early life. Childhood respiratory disease, maltreatment, maternal smoking and low birth weight increase the risk of COPD. Promising advances in prevention strategies for early life exposures could markedly decrease the risk of COPD.

Characteristics and Prevalence of Early Chronic Obstructive Pulmonary Disease in a Middle-Aged Population: Results from a Nationwide-Representative Sample

Introduction

Few studies have examined the prevalence and associated factors of early chronic obstructive pulmonary disease (COPD) in Asians.

Objective

To evaluate the prevalence of early COPD and its associated factors among non-institutionalized middle-aged Korean adults.

Methods

A total of 3195 participants aged 40–49 years from the 2016–2018 Korea National Health and Nutrition Examination Survey were included in this study. Patients (1) aged less than 50 years, (2) with a minimum of 10 pack-years of smoking, and (3) with forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) below the lower limit of normal were diagnosed with early COPD. The prevalence and odds ratio (OR) for early COPD were measured using multivariate logistic regression analysis, and the demographic data, anthropometric measurements, socioeconomic status, and lifestyle factors were considered covariates.

Results

The overall prevalence of early COPD among the middle-aged Korean population was 2.4% (4.4% in men and 0.4% in women), while that in participants with ≥10 pack-years was 8.2% (8.1% in men and 11.3% in women). A multivariate logistic regression model showed that male sex, urban residence, chronic sputum production, and hypertriglyceridemia were associated with increased ORs for early COPD in middle-aged, non-institutionalized Korean adults.

Conclusion

Early COPD is prevalent among middle-aged smokers in Korea. Efforts are needed to reduce the potential negative effects of early COPD on public health in Korea and other Asian countries.