Early chronic obstructive pulmonary disease: definition, assessment, and prevention

Global, regional, and national burden of young COPD, 1990-2021, with forecasts to 2050: a systematic analysis for the global burden of disease study 2021

BACKGROUND

Young chronic obstructive pulmonary disease (COPD) refers to people with COPD between the ages of 20 and 50 years. Current epidemiological studies focus on local geography, and there is a lack of global-level analysis. This study provides in-depth analyses of the disease burden of young COPD at global, regional, and national levels.

METHODS

This study used the Global Burden of Disease Study 2021 (GBD). The age-standardised prevalence rate (ASPR), age-standardised incidence rate (ASIR), age-standardised death rate (ASDR), and age-standardised disability-adjusted life years (DALYs) rate were used to describe the disease burden. The estimated annual percentage change (EAPC) during the study period was calculated. Joinpoint regression analysis examined the time trend from 1990 to 2021. Annual percentage change (APC) and average annual percentage change (AAPC) were calculated. Risk factors were reported by region and sex.

RESULTS

In 2021, the global number of young COPD cases was 30,384,539, and the ASPR, ASIR, ASDR, and age-standardised DALYs rates fell slightly. Oceania reported the highest ASPR, ASDR, and age-standardised DALYs rate. High-income North America has the highest ASIR. In 2021, the prevalence, incidence, death, and DALYs rates exhibited similar trends, increasing with age. From 1990 to 2021, both the prevalence and death rates showed a consistent downward trend across all age groups. Joinpoint regression analysis indicated a slight increase in both the ASPR (APC: 0.13; 95% CI: 0.06 to 0.19) and the ASIR (APC: 0.17; 95% CI: 0.10 to 0.24) during the period from 1990 to 1994. The leading DALYs attributable to risk factors for young COPD are household air pollution from solid fuels (20.4%), ambient particulate matter pollution (17.9%), and smoking (13.5%).

CONCLUSIONS

The global burden of ASPR, ASIR, ASDR, and age-standardised DALYs rates in young COPD has decreased, however, the absolute number of patients has increased. The global burden shows noticeable regional differences, with particularly high burdens observed in Oceania. Improving air quality, promoting smoking cessation, and increasing access to lung function tests, raising awareness of young COPD are key strategies for alleviating the burden of young COPD.

Demographic and Clinical Characteristics of Mild, Young and Early COPD: A Cross-Sectional Analysis of 5468 Patients

Early, mild and young COPD concepts are not clearly defined and are often used interchangeably to refer to the onset of the disease. Objective: To describe and compare the characteristics of mild, young and early COPD in a large sample of COPD from primary and secondary care. Methods: Pooled analysis of individual data from four multicenter observational studies of patients with stable COPD (≥40 years, FEV1/FVC < 0.7, smoking ≥ 10 pack-years). Mild COPD was defined as FEV1% ≥ 65%; young COPD as <55 years; and early COPD as <55 years and smoking ≤ 20 pack-years. The relationship between FEV1(%), age and pack-years was analyzed with linear regression equations. Results: We included 5468 patients. Their mean age was 67 (SD: 9.6) years, and 85% were male. A total of 1158 (21.2%) patients had mild COPD; 636 (11.6%) had young COPD and 191 (3.5%) early COPD. The three groups shared common characteristics: they were more frequently female, younger and with less tobacco exposure compared with the remaining patients. Early COPD had fewer comorbidities and fewer COPD admissions, but no significant differences were found in ambulatory exacerbations. In linear regression analysis, the decline in FEV1(%) was more pronounced for the first 20 pack-years for all age groups and was even more important in younger patients. Conclusions: Mild, young and early COPD patients were more frequently women. The steepest decline in FEV1(%) was observed in individuals <55 years and smoking between 10 and 20 pack-years (early COPD), which highlights the importance of an early detection and implementation of preventive and therapeutic measures.

Assessment of pulmonary function in COPD patients using dynamic digital radiography: A novel approach utilizing lung signal intensity changes during forced breathing

Objectives

To investigate the association of lung signal intensity changes during forced breathing using dynamic digital radiography (DDR) with pulmonary function and disease severity in patients with chronic obstructive pulmonary disease (COPD).

Methods

This retrospective study included 46 healthy subjects and 33 COPD patients who underwent posteroanterior chest DDR examination. We collected raw signal intensity and gray-scale image data. The lung contour was extracted on the gray-scale images using our previously developed automated lung field tracking system and calculated the average of signal intensity values within the extracted lung contour on gray-scale images. Lung signal intensity changes were quantified as SImax/SImin, representing the maximum ratio of the average signal intensity in the inspiratory phase to that in the expiratory phase. We investigated the correlation between SImax/SImin and pulmonary function parameters, and differences in SImax/SImin by disease severity.

Results

SImax/SImin showed the highest correlation with VC (rs = 0.54, P < 0.0001), followed by FEV1 (rs = 0.44, P < 0.0001), both of which are key indicators of COPD pathophysiology. In a multivariate linear regression analysis adjusted for confounding factors, SImax/SImin was significantly lower in the severe COPD group compared to the normal group (P = 0.0004) and mild COPD group (P=0.0022), suggesting its potential usefulness in assessing COPD severity.

Conclusion

This study suggests that the signal intensity changes of lung fields during forced breathing using DDR reflect the pathophysiology of COPD and can be a useful index in assessing pulmonary function in COPD patients, potentially improving COPD diagnosis and management.

Anti-pneumoconiosis effect of schisantherin A in PMA-induced A549 cells and SiO2/TiO2nanoparticles-induced acute pulmonary injury in mice

There has been significant global interest in respiratory health driven by the coronavirus disease (COVID-19) and severe environmental pollution. This study explored the potential of schisantherin A (SchA), a compound derived from Schisandra chinensis, to protect against acute pneumoconiosis. We assessed the effects of SchA on phorbol 12-myristate 13-acetate (PMA)-stimulated A549 alveolar epithelial cells and SiO2/TiO2-induced pulmonary injury in mice. In A549 cells, SchA significantly decreased pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and interleukin (IL)-8 levels. SchA-mediated reduction in inflammatory mediators was associated with the downregulation of PMA-stimulated nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling activation. In SiO2/TiO2-induced lung-injured mice, SchA administration significantly reduced MUC5AC production in lung tissue. SchA administration significantly downregulated the overexpression of NK-κB and the subsequent production of COX-2, iNOS, and NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasomes. It significantly suppressed expected increases in total cell numbers and pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and IL-1β in the bronchoalveolar lavage fluid (BALF) in SiO2/TiO2-stimulated mice. In contrast, the SiO2/TiO2-mediated decrease in IL-10 levels was significantly improved by SchA treatment. These fundamental results can be used to develop potential treatments involving SchA for acute pneumoconiosis.

Immune system benefits of pulmonary rehabilitation in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by pulmonary and systemic inflammation. Inflammatory mediators show relationships with shortness of breath, exercise intolerance and health related quality of life. Pulmonary rehabilitation (PR), a comprehensive education and exercise training programme, is the most effective therapy for COPD and is associated with reduced exacerbation and hospitalization rates and increased survival. Exercise training, the primary physiological intervention within PR, is known to exert a beneficial anti-inflammatory effect in health and chronic diseases. The question of this review article is whether exercise training can also make such a beneficial anti-inflammatory effect in COPD. Experimental studies using smoke exposure mice models suggest that the response of the immune system to exercise training is favourably anti-inflammatory. However, the evidence about the response of most known inflammatory mediators (C-reactive protein, tumour necrosis factor α, interleukin 6, interleukin 10) to exercise training in COPD patients is inconsistent, making it difficult to conclude whether regular exercise training has an anti-inflammatory effect in COPD. It is also unclear whether COPD patients with more persistent inflammation are a subgroup that would benefit more from hypothesized immunomodulatory effects of exercise training (i.e., personalized treatment). Nevertheless, it seems that PR combined with maintenance exercise training (i.e., lifestyle change) might be more beneficial in controlling inflammation and slowing disease progress in COPD patients, specifically in those with early stages of disease.

Effects of Tibetan medicine Longdan zhike tablet on chronic obstructive pulmonary disease through MAPK pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Longdan zhike tablet (LDZK) is a Tibetan medicine formula commonly used in the highland region of Tibet, China, to ameliorate respiratory diseases, such as acute bronchitis and asthma. In Chinese traditional medicine, some herbal formulas with anti-inflammatory properties targeting the respiratory system are clinically adopted as supplementary therapies for chronic obstructive pulmonary disease (COPD). However, the specific anti-COPD effects of LDZK remain to be evaluated.

AIM OF THE STUDY

The aim of this study is to identify the principal bioactive compounds in LDZK, and elucidate the effects and mechanisms of the LDZK on COPD.

METHODS

High-resolution mass spectrometry was utilized for a comprehensive characterization of the chemical composition of LDZK. The therapeutic effects of LDZK were assessed on the LPS-papain-induced COPD mouse model, and LPS-induced activation model of A549 cells. The safety of LDZK was evaluated by orally administering a single dose of 30 g/kg to rats and monitoring physiological and biochemical indicators after a 14-day period. Network pharmacology and Western blot analysis were employed for mechanism prediction of LDZK.

RESULTS

A comprehensive analysis identified a total of 45 compounds as the major constituents of LDZK. Oral administration of LDZK resulted in notable ameliorative effects in respiratory function, accompanied by reduced inflammatory cell counts and cytokine levels in the lungs of COPD mice. Acute toxicity tests demonstrated a favorable safety profile at a dose equivalent to 292 times the clinically prescribed dose. In vitro studies revealed that LDZK exhibited protective effects on A549 cells by mitigating LPS-induced cellular damage, reducing the release of NO, and downregulating the expression of iNOS, COX2, IL-1β, IL-6, and TNF-α. Network pharmacology and Western blot analysis indicated that LDZK primarily modulated the MAPK signaling pathway and inhibited the phosphorylation of p38/ERK/JNK.

CONCLUSIONS

LDZK exerts significant therapeutic effects on COPD through the regulation of the MAPK pathway, suggesting its potential as a promising adjunctive therapy for the treatment of chronic inflammation in COPD.

Early Diagnosis and Treatment of COPD and Asthma - A Randomized, Controlled Trial

BACKGROUND

Many persons with chronic obstructive pulmonary disease (COPD) or asthma have not received a diagnosis, so their respiratory symptoms remain largely untreated.

METHODS

We used a case-finding method to identify adults in the community with respiratory symptoms without diagnosed lung disease. Participants who were found to have undiagnosed COPD or asthma on spirometry were enrolled in a multicenter, randomized, controlled trial to determine whether early diagnosis and treatment reduces health care utilization for respiratory illness and improves health outcomes. Participants were assigned to receive the intervention (evaluation by a pulmonologist and an asthma-COPD educator who were instructed to initiate guideline-based care) or usual care by their primary care practitioner. The primary outcome was the annualized rate of participant-initiated health care utilization for respiratory illness. Secondary outcomes included changes from baseline to 1 year in disease-specific quality of life, as assessed with the St. George Respiratory Questionnaire (SGRQ; scores range from 0 to 100, with lower scores indicating better health status); symptom burden, as assessed with the COPD Assessment Test (CAT; scores range from 0 to 40, with lower scores indicating better health status); and forced expiratory volume in 1 second (FEV1).

RESULTS

Of 38,353 persons interviewed, 595 were found to have undiagnosed COPD or asthma and 508 underwent randomization: 253 were assigned to the intervention group and 255 to the usual-care group. The annualized rate of a primary-outcome event was lower in the intervention group than in the usual-care group (0.53 vs. 1.12 events per person-year; incidence rate ratio, 0.48; 95% confidence interval [CI], 0.36 to 0.63; P<0.001). At 12 months, the SGRQ score was lower than the baseline score by 10.2 points in the intervention group and by 6.8 points in the usual-care group (difference, -3.5 points; 95% CI, -6.0 to -0.9), and the CAT score was lower than the baseline score by 3.8 points and 2.6 points, respectively (difference, -1.3 points; 95% CI, -2.4 to -0.1). The FEV1 increased by 119 ml in the intervention group and by 22 ml in the usual-care group (difference, 94 ml; 95% CI, 50 to 138). The incidence of adverse events was similar in the trial groups.

CONCLUSIONS

In this trial in which a strategy was used to identify adults in the community with undiagnosed asthma or COPD, those who received pulmonologist-directed treatment had less subsequent health care utilization for respiratory illness than those who received usual care. (Funded by Canadian Institutes of Health Research; UCAP ClinicalTrials.gov number, NCT03148210.).

Unravelling the complex interplay of factors behind exercise limitations and physical inactivity in COPD

Exercise limitation and physical inactivity are known treatable traits for people with COPD. Maximising exercise capacity and keeping people physically active improves health status and survival rates among people with COPD. However, managing these two treatable traits can be extremely challenging for clinicians due to the complex intersectionality of factors influencing an individual's capacity, opportunity and motivation to engage in physical activity. This review presents the complex factors influencing exercise capacity ("can do"), levels of physical activity ("do do") and sedentary behaviours amongst people with COPD and provides practical recommendations on how clinicians can address some of these factors in practice. Most importantly, it highlights the importance of referring to pulmonary rehabilitation as a way to improve exercise capacity among people with COPD.

Discriminative potential of exhaled breath condensate biomarkers with respect to chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) affecting 334 million people in the world remains a major cause of morbidity and mortality. Proper diagnosis of COPD is still a challenge and largely solely based on spirometric criteria. We aimed to investigate the potential of nitrosative/oxidative stress and related metabolic biomarkers in exhaled breath condensate (EBC) to discriminate COPD patients.

METHODS

Three hundred three participants were randomly selected from a 15,000-transit worker cohort within the Respiratory disease Occupational Biomonitoring Collaborative Project (ROBoCoP). COPD was defined using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria as post-bronchodilator ratio of Forced Expiratory Volume in 1st second to Forced Vital Capacity < 0.7 in spirometry validated by an experienced pulmonologist. Discriminative power of biomarker profiles in EBC was analyzed using linear discriminant analyses.

RESULTS

Amongst 300 participants with validated spirometry, 50.3% were female, 52.3 years old in average, 36.0% were current smokers, 12.7% ex-smokers with mean tobacco exposure of 15.4 pack-years. Twenty-one participants (7.0%) were diagnosed as COPD, including 19 new diagnoses, 12 of which with a mild COPD stage (GOLD 1). Amongst 8 biomarkers measured in EBC, combination of 2 biomarkers, Lactate and Malondialdehyde (MDA) significantly discriminated COPD subjects from non-COPD, with a 71%-accuracy, area under the receiver curve of 0.78 (p-value < 0.001), and a negative predictive value of 96%.

CONCLUSIONS

These findings support the potential of biomarkers in EBC, in particular lactate and MDA, to discriminate COPD patients even at a mild or moderate stage. These EBC biomarkers present a non-invasive and drugless technique, which can improve COPD diagnosis in the future.

Contribution of small airway inflammation to the development of COPD

BACKGROUND

Little attention has been paid to the pathophysiological changes in the natural history of chronic obstructive pulmonary disease (COPD). The destructions of the small airways were visualized on thoracic micro-computed tomography scan. We investigated whether small airway inflammation (SAI) was the risk for the development of COPD.

METHODS

A total of 1062 patients were enrolled and analyzed in the study. The partitioned airway inflammation was determined by exhaled nitric oxide (NO) of FnNO, FeNO50, FeNO200, and calculated CaNOdual. Both FeNO200 and CaNOdual were compared to detect the promising predictor for peripheral airway/alveolar inflammation in COPD. The correlation between exhaled NO and white cell classification was evaluated to determine the inflammation type during the development of COPD.

RESULTS

Exhaled NO levels (FnNO, FeNO50, FeNO200, and CaNOdual) were the highest in the COPD group compared with all other groups. Furthermore, compared with controls, exhaled NO levels (FeNO50, FeNO200, and CaNOdual) were also significantly higher in the emphysema, chronic bronchitis, and smoking groups. FeNO200 was found to be a promising predictor for peripheral airway/alveolar inflammation (area under the curve [AUC] of the receiver operating characteristic [ROC] curve, area under the curve [AUC] = 0.841) compared with CaNOdual (AUC ROC = 0.707) in COPD. FeNO200 was the main risk factor (adjusted odds ratio, 2.191; 95% CI, 1.797-2.671; p = 0.002) for the development of COPD. The blood eosinophil and basophil levels were correlated with FeNO50 and FeNO200.

CONCLUSION

The complete airway inflammations were shown in COPD, whereas SAI was the main risk factor for the development of COPD, which might relate to eosinophil and basophil levels.

Prevalence and Associated Factors of Chronic Obstructive Pulmonary Disease Among Adults in Neno District, Malawi: A Cross-Sectional Analytical Study

Introduction

Chronic obstructive pulmonary disease (COPD) continues to pose a global public health challenge. However, literature is scarce on the burden of COPD in Malawi. We assessed the prevalence and risk factors for COPD among adults in Neno, Malawi.

Methodology

We conducted a population-based analytical cross-sectional study in Neno District between December 2021 and November 2022. Using a multi-stage sampling technique, we included 525 adults aged≥40 years. All participants underwent spirometry according to the American Thoracic Society (ATS) guidelines and were interviewed using the IMPALA questionnaire. For this study, we utilized the definition of COPD as a post-bronchodilator FEV1/FVC <0.70. We collected data using Kobo collect, exported to Microsoft Excel, and analysed using R software. We used descriptive statistics and logistic regression analysis; a p-value of <0.05 was considered statistically significant.

Results

Out of 525 participants, 510 participants were included in the final analysis. Fifty-eight percent of the participants were females (n=296), and 62.2% (n=317) were between 40 and 49 years with a median (IQR) age of 46 (40-86). For patient characteristics, 15.1% (n=77) were current smokers, and 4.1% (n=21) had a history of pulmonary tuberculosis (PTB). Cough was the most commonly reported respiratory symptom (n=249, 48.8%). The prevalence of COPD was 10.0% (n=51) and higher (15.0%) among males compared to females (6.4%). Factors significantly associated with COPD were age 60 years and above (adjusted odds ratio [aOR] = 3.27, 95% CI: 1.48-7.34, p<0.004), ever smoked (aOR = 6.17, 95% CI:1.89-18.7, p<0.002), current smoker (aOR = 17.6, 95% CI: 8.47-38.4, p<0.001), and previous PTB (aOR = 4.42, 95% CI: 1.16-15.5, p<0.023).

Conclusion

The cross-sectional prevalence of COPD in rural Malawi is high, especially among males. Factors significantly associated were older age (60 years and above), cigarette smoking, and previous PTB. Longitudinal studies are needed to better understand disease etiology and progression in this setting.

Breath biomarkers in Non-Carcinogenic diseases

The analysis of volatile organic compounds (VOCs) from human matrices like breath, perspiration, and urine has received increasing attention from academic and medical researchers worldwide. These biological-borne VOCs molecules have characteristics that can be directly related to physiologic and pathophysiologic metabolic processes. In this work, gathers a total of 292 analytes that have been identified as potential biomarkers for the diagnosis of various non-carcinogenic diseases. Herein we review the advances in VOCs with a focus on breath biomarkers and their potential role as minimally invasive tools to improve diagnosis prognosis and therapeutic monitoring.

Long-acting muscarinic antagonist and long-acting β2-agonist combination for the treatment of maintenance therapy-naïve patients with chronic obstructive pulmonary disease: a narrative review

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Faster lung function impairment occurs earlier in the disease, particularly in mild-to-moderate COPD, highlighting the need for early and effective targeted interventions. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2024 report recommends initial pharmacologic treatment with a long-acting muscarinic antagonist (LAMA) and long-acting β2-agonist (LABA) combination in group B (0 or 1 moderate exacerbation not leading to hospitalization, modified Medical Research Council score of ⩾2, and COPD Assessment Test™ score of ⩾10) and E (⩾2 moderate exacerbations or ⩾1 exacerbation leading to hospitalization and blood eosinophil count <300 cells/µL) patients. In randomized controlled trials (RCTs), LAMA/LABA combination therapy improved lung function, St. George's Respiratory Questionnaire (SGRQ) total score, and Transitional Dyspnea Index (TDI) focal score and reduced the use of rescue medications, exacerbation risk, and risk of first clinically important deterioration (CID), compared with LAMA or LABA monotherapy. However, there is limited evidence regarding the efficacy and safety of LAMA/LABA combination therapy versus LAMA or LABA monotherapy in maintenance therapy-naïve patients. This review discusses the rationale for the early initiation of LAMA/LABA combination therapy in maintenance therapy-naïve patients with COPD. In post hoc analyses of pooled data from RCTs, compared with LAMA or LABA monotherapy, LAMA/LABA combination therapy improved lung function and quality of life and reduced COPD symptoms, risk of first moderate/severe exacerbation, risk of first CID, and use of rescue medication, with no new safety signals. In a real-world study, patients initiating LAMA/LABA had significantly reduced risk of COPD-related inpatient admissions and rate of on-treatment COPD-related inpatient admissions over 12 months than those initiating LAMA. Consequently, LAMA/LABA combination therapy could be considered the treatment of choice in maintenance therapy-naïve patients with COPD, as recommended by the GOLD 2024 report.

Impact of Undiagnosed Chronic Obstructive Pulmonary Disease and Asthma on Symptoms, Quality of Life, Healthcare Use, and Work Productivity

Rationale: A significant proportion of individuals with chronic obstructive pulmonary disease (COPD) and asthma remain undiagnosed. Objectives: The objective of this study was to evaluate symptoms, quality of life, healthcare use, and work productivity in subjects with undiagnosed COPD or asthma compared with those previously diagnosed, as well as healthy control subjects. Methods: This multicenter population-based case-finding study randomly recruited adults with respiratory symptoms who had no previous history of diagnosed lung disease from 17 Canadian centers using random digit dialing. Participants who exceeded symptom thresholds on the Asthma Screening Questionnaire or the COPD Diagnostic Questionnaire underwent pre- and post-bronchodilator spirometry to determine if they met diagnostic criteria for COPD or asthma. Two control groups, a healthy group without respiratory symptoms and a symptomatic group with previously diagnosed COPD or asthma, were similarly recruited. Measurements and Main Results: A total of 26,905 symptomatic individuals were interviewed, and 4,272 subjects were eligible. Of these, 2,857 completed pre- and post-bronchodilator spirometry, and 595 (21%) met diagnostic criteria for COPD or asthma. Individuals with undiagnosed COPD or asthma reported greater impact of symptoms on health status and daily activities, worse disease-specific and general quality of life, greater healthcare use, and poorer work productivity than healthy control subjects. Individuals with undiagnosed asthma had symptoms, quality of life, and healthcare use burden similar to those of individuals with previously diagnosed asthma, whereas subjects with undiagnosed COPD were less disabled than those with previously diagnosed COPD. Conclusions: Undiagnosed COPD or asthma imposes important, unmeasured burdens on the healthcare system and is associated with poor health status and negative effects on work productivity.

The State of the Art on Graphene-Based Sensors for Human Health Monitoring through Breath Biomarkers

The field of organic-borne biomarkers has been gaining relevance due to its suitability for diagnosing pathologies and health conditions in a rapid, accurate, non-invasive, painless and low-cost way. Due to the lack of analytical techniques with features capable of analysing such a complex matrix as the human breath, the academic community has focused on developing electronic noses based on arrays of gas sensors. These sensors are assembled considering the excitability, sensitivity and sensing capacities of a specific nanocomposite, graphene. In this way, graphene-based sensors can be employed for a vast range of applications that vary from environmental to medical applications. This review work aims to gather the most relevant published papers under the scope of "Graphene sensors" and "Biomarkers" in order to assess the state of the art in the field of graphene sensors for the purposes of biomarker identification. During the bibliographic search, a total of six pathologies were identified as the focus of the work. They were lung cancer, gastric cancer, chronic kidney diseases, respiratory diseases that involve inflammatory processes of the airways, like asthma and chronic obstructive pulmonary disease, sleep apnoea and diabetes. The achieved results, current development of the sensing sensors, and main limitations or challenges of the field of graphene sensors are discussed throughout the paper, as well as the features of the experiments addressed.

Smoking exposure trajectories and pulmonary function in early adulthood in a Brazilian cohort

OBJECTIVES

To investigate smoking trajectories and their association with pulmonary function (PF) and respiratory symptoms at age 22.

METHODS

Data from a population-based cohort study of 3350 individuals and their spirometries were analysed. The outcomes were: forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), forced expiratory flow at the mid expiratory phase (FEF25-75 %), FEV1/FVC and FEF25-75/FVC ratio. Smoking data were collected at perinatal follow-up (gestational exposure) and 15, 18 and 22 years. Group-based trajectory model was applied.

RESULTS

Four groups were identified: no exposure (NE), gestational (GE), gestational and adulthood (GAE) and continuous (CE) exposure. Both CE and GAE trajectories were associated with lower values of FEV1/FVC (-1.77pp; p = 0.01 and -1.58 pp; p<0.001 respectively) and FEF25-75/FVC ratio (-7.27pp; p = 0.019 and -6.04pp; p<0.001 respectively) compared to the NE trajectory. Lower FEV1 and FEF25-75 % values were also related to the GAE trajectory (-68 ml; p = 0.03 and -253 ml/s;p<0.001 respectively). Compared to those who never smoked, individuals who smoked 10 or more cigarettes daily presented a reduction in the FEV1/FVC ratio by 1.37pp (p<0.001), FEF25-75 % by 126 ml (p = 0.012) and FEF25-75 %/FVC ratio by 3.62pp (p = 0.011). CE trajectory showed higher odds of wheezing (OR 4.14; p<0.001) and cough (OR 2.39; p = 0.002) compared to the non-exposed group.

CONCLUSIONS

The in-uterus exposure to maternal smoking reduces PF later in life. However, the perpetuation of smoking behaviour throughout adolescence and early adulthood is determinant for PF main reduction and the emergence of respiratory-related symptoms.

Subtypes of Patients with Mild to Moderate Airflow Limitation as Predictors of Chronic Obstructive Pulmonary Disease Exacerbation

COPD is a heterogeneous disease, and its acute exacerbation is a major prognostic factor. We used cluster analysis to predict COPD exacerbation due to subtypes of mild-moderate airflow limitation. In all, 924 patients from the Korea COPD Subgroup Study cohort, with a forced expiratory volume (FEV1) ≥ 50% and documented age, body mass index (BMI), smoking status, smoking pack-years, COPD assessment test (CAT) score, predicted post-bronchodilator FEV1, were enrolled. Four groups, putative chronic bronchitis (n = 224), emphysema (n = 235), young smokers (n = 248), and near normal (n = 217), were identified. The chronic bronchitis group had the highest BMI, and the one with emphysema had the oldest age, lowest BMI, and highest smoking pack-years. The young smokers group had the youngest age and the highest proportion of current smokers. The near-normal group had the highest proportion of never-smokers and near-normal lung function. When compared with the near-normal group, the emphysema group had a higher risk of acute exacerbation (OR: 1.93, 95% CI: 1.29-2.88). However, multiple logistic regression showed that chronic bronchitis (OR: 2.887, 95% CI: 1.065-8.192), predicted functional residual capacity (OR: 1.023, 95% CI: 1.007-1.040), fibrinogen (OR: 1.004, 95% CI: 1.001-1.008), and gastroesophageal reflux disease were independent predictors of exacerbation (OR: 2.646, 95% CI: 1.142-6.181). The exacerbation-susceptible subtypes require more aggressive prevention strategies.

Relationship between early life asthma and chronic airway disease in adult life - in search for disease trajectories over the life span- the RELATE study based on the Kongsberg cohort

BACKGROUND

Chronic airway disease in adults may have its origin in early life. The purpose of this study is to investigate the long-term prognosis of severe childhood asthma in search for an association between asthma in early life and obstructive lung disease in adulthood.

METHODS

This study is based on the Kongsberg cohort, which includes approximately 5000 children with severe asthma with a 4-month stay at the asthma care facility in Kongsberg, Norway during the years 1950 to 1979. An on average 60-year observational study based on a follow-up examination will be performed including questionnaires, blood samples, and tests of lung function and bronchial responsiveness. Blood samples will be stored in a biobank. In addition, we will conduct further analyses of the cohort based on nationwide register data, including socio-economic parameters and mortality.

DISCUSSION

Chronic airway disease is associated with substantial burden for both the individual patient and society. Our knowledge of early life origins of chronic airway disease later in life has been increasing in recent decades but is still limited. By exploring early life risk factors for chronic airway disease in adulthood, we may gain insights paving the way for future reduction in the burden of chronic airway diseases.

Remote regulation of rs80245547 and rs72673891 mediated by transcription factors C-Jun and CREB1 affect GSTCD expression

Chronic obstructive pulmonary disease (COPD), the third leading cause of death worldwide, is influenced by genetic factors. The genetic signal rs10516526 in the glutathione S-transferase C-terminal domain containing (GSTCD) gene is a highly significant and reproducible signal associated with lung function and COPD on chromosome 4q24. In this study, comprehensive bioinformatics analyses and experimental verifications were detailly implemented to explore the regulation mechanism of rs10516526 and GSTCD in COPD. The results suggested that low expression of GSTCD was associated with COPD (p = 0.010). And C-Jun and CREB1 transcription factors were found to be essential for the regulation of GSTCD by rs80245547 and rs72673891. Moreover, rs80245547T and rs72673891G had a stronger binding ability to these transcription factors, which may promote the allele-specific long-range enhancer-promoter interactions on GSTCD, thus making COPD less susceptible. Our study provides a new insight into the relationship between rs10516526, GSTCD, and COPD.

Understanding COPD Etiology, Pathophysiology, and Definition

COPD, one of the leading worldwide health problems, currently lacks truly disease-modifying medical therapies applicable to most patients. Developing such novel therapies has been hampered by the marked heterogeneity of phenotypes between individuals with COPD. Such heterogeneity suggests that, rather than a single cause (particularly just direct inhalation of tobacco products), development and progression of COPD likely involve both complex gene-by-environment interactions to multiple inhalational exposures and a variety of molecular pathways. However, there has been considerable recent progress toward understanding how specific pathological processes can lead to discrete COPD phenotypes, particularly that of small airways disease. Advances in imaging techniques that correlate to specific types of histological damage, and in the immunological mechanisms of lung damage in COPD, hold promise for development of personalized therapies. At the same time, there is growing recognition that the current diagnostic criteria for COPD, based solely on spirometry, exclude large numbers of individuals with very similar disease manifestations. This concise review summarizes current understanding of the etiology and pathophysiology of COPD and provides background explaining the increasing calls to expand the diagnostic criteria used to diagnose COPD and some challenges in doing so.

Twenty years of changes in the definition of early chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory airway disease that affects the quality of life of nearly one-tenth of the global population. Due to irreversible airflow obstruction and progressive lung function decline, COPD is characterized by high mortality and disability rates, which imposes a huge economic burden on society. In recent years, the importance of intervention in the early stage of COPD has been recognized and the concept of early COPD has been proposed. Identifying and intervening in individuals with early COPD, some of whom have few or no symptoms, might halt or reverse the progressive decline in lung function, improve the quality of life, and better their prognosis. However, understanding of early COPD is not yet well established, and there are no unified and feasible diagnostic criteria, which complicates clinical research. In this article, we review evolution of the definition of early COPD over the past 20 years, describe the changes in awareness of this concept, and propose future research directions.

Fractional Dynamics Foster Deep Learning of COPD Stage Prediction

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death worldwide. Current COPD diagnosis (i.e., spirometry) could be unreliable because the test depends on an adequate effort from the tester and testee. Moreover, the early diagnosis of COPD is challenging. The authors address COPD detection by constructing two novel physiological signals datasets (4432 records from 54 patients in the WestRo COPD dataset and 13824 medical records from 534 patients in the WestRo Porti COPD dataset). The authors demonstrate their complex coupled fractal dynamical characteristics and perform a fractional-order dynamics deep learning analysis to diagnose COPD. The authors found that the fractional-order dynamical modeling can extract distinguishing signatures from the physiological signals across patients with all COPD stages-from stage 0 (healthy) to stage 4 (very severe). They use the fractional signatures to develop and train a deep neural network that predicts COPD stages based on the input features (such as thorax breathing effort, respiratory rate, or oxygen saturation). The authors show that the fractional dynamic deep learning model (FDDLM) achieves a COPD prediction accuracy of 98.66% and can serve as a robust alternative to spirometry. The FDDLM also has high accuracy when validated on a dataset with different physiological signals.

Development of a prediction model to identify undiagnosed chronic obstructive pulmonary disease patients in primary care settings in China

BACKGROUND

At present, a large number of chronic obstructive pulmonary disease (COPD) patients are undiagnosed in China. Thus, this study aimed to develop a simple prediction model as a screening tool to identify patients at risk for COPD.

METHODS

The study was based on the data of 22,943 subjects aged 30 to 79 years and enrolled in the second resurvey of China Kadoorie Biobank during 2012 and 2013 in China. We stepwisely selected the predictors using logistic regression model. Then we tested the model validity through P-P graph, area under the receiver operating characteristic curve (AUROC), ten-fold cross validation and an external validation in a sample of 3492 individuals from the Enjoying Breathing Program in China.

RESULTS

The final prediction model involved 14 independent variables, including age, sex, location (urban/rural), region, educational background, smoking status, smoking amount (pack-years), years of exposure to air pollution by cooking fuel, family history of COPD, history of tuberculosis, body mass index, shortness of breath, sputum and wheeze. The model showed an area under curve (AUC) of 0.72 (95% confidence interval [CI]: 0.72-0.73) for detecting undiagnosed COPD patients, with the cutoff of predicted probability of COPD=0.22, presenting a sensitivity of 70.13% and a specificity of 62.25%. The AUROC value for screening undiagnosed patients with clinically significant COPD was 0.68 (95% CI: 0.66-0.69). Moreover, the ten-fold cross validation reported an AUC of 0.72 (95% CI: 0.71-0.73), and the external validation presented an AUC of 0.69 (95% CI: 0.68-0.71).

CONCLUSION

This prediction model can serve as a first-stage screening tool for undiagnosed COPD patients in primary care settings.

Dynamic analysis of gene signatures in the progression of COPD

Aims

Oxidative stress is an important amplifying mechanism in COPD; however, it is unclear how oxidative stress changes and what its exact amplification mechanism is in the pathological process. We aimed to dynamically analyse the progression of COPD and further elucidate the characteristics of each developmental stage and unveil the underlying mechanisms.

Methods

We performed a holistic analysis by integrating Gene Expression Omnibus microarray datasets related to smoking, emphysema and Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification based on the concept of gene, environment and time (GET). Gene ontology (GO), protein-protein interaction (PPI) networks and gene set enrichment analysis (GSEA) were used to explore the changing characteristics and potential mechanisms. Lentivirus was used to promote HIF3A overexpression.

Results

In smokers versus nonsmokers, the GO term mainly enriched in "negative regulation of apoptotic process". In later transitions between stages, the main enriched terms were continuous progression of "oxidation-reduction process" and "cellular response to hydrogen peroxide". Logistic regression showed that these core differentially expressed genes (DEGs) had diagnostic accuracy in test (area under the curve (AUC)=0.828) and validation (AUC=0.750) sets. GSEA and PPI networks showed that one of the core DEGs, HIF3A, strongly interacted with the ubiquitin-mediated proteolysis pathway. Overexpression of HIF3A restored superoxide dismutase levels and alleviated the reactive oxygen species accumulation caused by cigarette smoke extract treatment.

Conclusion

Oxidative stress was continuously intensified from mild emphysema to GOLD 4; thus, special attention should be paid to the identification of emphysema. Furthermore, the downregulated HIF3A may play an important role in the intensified oxidative stress in COPD.

Lifetime spirometry patterns of obstruction and restriction, and their risk factors and outcomes: a prospective cohort study

BACKGROUND

Interest in lifetime lung function trajectories has increased in the context of emerging evidence that chronic obstructive pulmonary disease (COPD) can arise from multiple disadvantaged lung function pathways, including those that stem from poor lung function in childhood. To our knowledge, no previous study has investigated both obstructive and restrictive lifetime patterns concurrently, while accounting for potential overlaps between them. We aimed to investigate lifetime trajectories of the FEV₁/forced vital capacity (FVC) ratio, FVC, and their combinations, relate these combined trajectory groups to static lung volume and gas transfer measurements, and investigate both risk factors for and consequences of these combined trajectory groups.

METHODS

Using z scores from spirometry measured at ages 7, 13, 18, 45, 50, and 53 years in the Tasmanian Longitudinal Health Study (n=2422), we identified six FEV₁/FVC ratio trajectories and five FVC trajectories via group-based trajectory modelling. Based on whether trajectories of the FEV₁/FVC ratio and FVC were low (ie, low from childhood or adulthood) or normal, four patterns of lifetime spirometry obstruction or restriction were identified and compared against static lung volumes and gas transfer. Childhood and adulthood characteristics and morbidities of these patterns were investigated.

FINDINGS

The prevalence of the four lifetime spirometry patterns was as follows: low FEV₁/FVC ratio only, labelled as obstructive-only, 25·8%; low FVC only, labelled as restrictive-only, 10·5%; both low FEV₁/FVC ratio and low FVC, labelled as mixed, 3·5%; and neither low FEV₁/FVC ratio nor low FVC, labelled as reference, 60·2%. The prevalence of COPD at age 53 years was highest in the mixed pattern (31 [37%] of 84 individuals) followed by the obstructive-only pattern (135 [22%] of 626 individuals). Individuals with the mixed pattern also had the highest prevalence of parental asthma, childhood respiratory illnesses, adult asthma, and depression. Individuals with the restrictive-only pattern had lower total lung capacity and residual volume, and had the highest prevalence of childhood underweight, adult obesity, diabetes, cardiovascular conditions, hypertension, and obstructive sleep apnoea.

INTERPRETATION

To our knowledge, this is the first study to characterise lifetime phenotypes of obstruction and restriction simultaneously using objective data-driven techniques and unique life course spirometry measures of FEV₁/FVC ratio and FVC from childhood to middle age. Mixed and obstructive-only patterns indicate those who might benefit from early COPD interventions. Those with the restrictive-only pattern had evidence of true lung restriction and were at increased risk of multimorbidity by middle age.

FUNDING

National Health and Medical Research Council of Australia, The University of Melbourne, Clifford Craig Medical Research Trust of Tasmania, The Victorian, Queensland & Tasmanian Asthma Foundations, The Royal Hobart Hospital, Helen MacPherson Smith Trust, and GlaxoSmithKline.

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.

Association of type 2 diabetes mellitus with lung cancer in patients with chronic obstructive pulmonary disease

Background

Patients with chronic obstructive pulmonary disease (COPD) have an increased risk of developing lung cancer. Some studies have also suggested that diabetes mellitus (DM) may increase the risk of developing lung cancer. This study aimed to investigate whether type 2 DM (T2DM) is associated with an increased risk of lung cancer in patients with COPD.

Materials and methods

We conducted a retrospective analysis on two cohorts: the National Health Insurance Service-National Sample Cohort (NHIS-NSC) of Korea and the Common Data Model (CDM) database of a university hospital. Among patients newly diagnosed with COPD in each cohort, those with a lung cancer diagnosis were included, and a control group was selected through propensity score matching. We used the Kaplan-Meier analysis and Cox proportional hazard models to compare lung cancer incidence between patients with COPD and T2DM and those without T2DM.

Results

In the NHIS-NSC and CDM cohorts, we enrolled 3,474 and 858 patients with COPD, respectively. In both cohorts, T2DM was associated with an increased risk of lung cancer [NHIS-NSC: adjusted hazard ratio (aHR), 1.20; 95% confidence interval (CI), 1.02-1.41; and CDM: aHR, 1.45; 95% CI, 1.02-2.07). Furthermore, in the NHIS-NSC, among patients with COPD and T2DM, the risk of lung cancer was higher in current smokers than in never-smokers (aHR, 1.45; 95% CI, 1.09-1.91); in smokers with ≥30 pack-years than in never-smokers (aHR, 1.82; 95% CI, 1.49-2.25); and in rural residents than in metropolitan residents (aHR, 1.33; 95% CI, 1.06-1.68).

Conclusion

Our findings suggest that patients with COPD and T2DM may have an increased risk of developing lung cancer compared to those without T2DM.

Pulmonary EV miRNA profiles identify disease and distinct inflammatory endotypes in COPD

Introduction

Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition without effective disease modifying therapies. Identification of novel inflammatory endotype markers such as extracellular vesicles (EVs), which are important intercellular messengers carrying microRNA (miRNA), may enable earlier diagnosis and disease stratification for a targeted treatment approach. Our aim was to identify differentially expressed EV miRNA in the lungs of COPD patients compared with healthy ex-smokers and determine whether they can help define inflammatory COPD endotypes.

Methods

EV miRNA were isolated and sequenced from ex-smoking COPD patients and healthy ex-smoker bronchoalveolar lavage fluid. Results were validated with RT-qPCR and compared to differential inflammatory cell counts.

Results

Expression analysis identified five upregulated miRNA in COPD (miR-223-3p, miR-2110, miR-182-5p, miR-200b-5p and miR-625-3p) and three downregulated miRNA (miR-138-5p, miR-338-3p and miR-204-5p), all with a log2 fold change of >1/-1, FDR < 0.05. These miRNAs correlated with disease defining characteristics such as FEF 25-75% (a small airways disease measure) and DLCO% (a surrogate measure of emphysema). Receiver operator curve analysis demonstrated miR-2110, miR-223-3p, and miR-182-5p showed excellent combinatory predictive ability (AUC 0.91, p < 0.0001) in differentiating between health and mild COPD. Furthermore, miR-223-3p and miR-338-3p correlated with airway eosinophilia and were able to distinguish "pure eosinophilic" COPD from other airway inflammatory subtypes (AUC 0.94 and 0.85, respectively).

Discussion

This is the first study to identify differentially expressed miRNA in COPD bronchoalveolar lavage fluid EVs. These findings suggest specific lung derived EV miRNA are a strong predictor of disease presence even in mild COPD. Furthermore, specific miRNA correlated with inflammatory cell numbers in COPD, and may have a role in defining inflammatory endotypes for future treatment stratification.

Hedgehog pathway and its inhibitors in chronic obstructive pulmonary disease (COPD)

COPD affects millions of people and is now ranked as the third leading cause of death worldwide. This largely untreatable chronic airway disease results in irreversible destruction of lung architecture. The small lung hypothesis is now supported by epidemiological, physiological and clinical studies. Accordingly, the early and severe COPD phenotype carries the most dreadful prognosis and finds its roots during lung growth. Pathophysiological mechanisms remain poorly understood and implicate individual susceptibility (genetics), a large part of environmental factors (viral infections, tobacco consumption, air pollution) and the combined effects of those triggers on gene expression. Genetic susceptibility is most likely involved as the disease is severe and starts early in life. The latter observation led to the identification of Mendelian inheritance via disease-causing variants of SERPINA1 - known as the basis for alpha-1 anti-trypsin deficiency, and TERT. In the last two decades multiple genome wide association studies (GWAS) identified many single nucleotide polymorphisms (SNPs) associated with COPD. High significance SNPs are located in 4q31 near HHIP which encodes an evolutionarily highly conserved physiological inhibitor of the Hedgehog signaling pathway (HH). HHIP is critical to several in utero developmental lung processes. It is also implicated in homeostasis, injury response, epithelial-mesenchymal transition and tumor resistance to apoptosis. A few studies have reported decreased HHIP RNA and protein levels in human adult COPD lungs. HHIP^+/- murine models led to emphysema. HH pathway inhibitors, such as vismodegib and sonidegib, are already validated in oncology, whereas other drugs have evidenced in vitro effects. Targeting the Hedgehog pathway could lead to a new therapeutic avenue in COPD. In this review, we focused on the early and severe COPD phenotype and the small lung hypothesis by exploring genetic susceptibility traits that are potentially treatable, thus summarizing promising therapeutics for the future.

A Retrospective Study of Diaphragmatic Breathing Training Combined with Discharge Care Bundles in Patients with Chronic Obstructive Pulmonary Disease

Objective. Both physical exercise and discharge care bundles can improve patient outcomes and reduce hospitalization rates among subjects with chronic obstructive pulmonary disease (COPD). The retrospective analysis aims to determine the advantages of care bundles combined with diaphragmatic breathing training (DBT) in COPD patients after discharge. Methods. Of the 110 COPD patients, 55 patients received DBT alone (DBT group) and 55 participants received the combined intervention (care bundle + DBT group). Three months after discharge, we assessed the outcomes of patients using Bristol COPD Knowledge Questionnaire (BCKQ), Hospital Anxiety and Depression Scale (HADS), COPD Assessment Test (CAT), and St. George’s Respiratory Questionnaire (SGRQ). Meanwhile, COPD-related hospital readmissions were also recorded. Results. The BCKQ score for assessing the disease knowledge level was increased in patients at 3 months after the combined interventions as compared to the baseline values, which was higher in the care bundle + DBT group than the DBT group at 3 months. Moreover, improvements in negative emotion and clinical symptoms from baseline to 3-month follow-up were seen in both the two groups. Besides, the care bundle + DBT group showed the mitigation of depression and anxiety and the alleviation of clinical symptoms in comparison with the DBT group at 3 months. Participants who received combined interventions had lower SGRQ scores than those who received DBT alone. The time to first COPD-related readmission was shorter for patients in the care bundle + DBT group compared with the DBT group. Conclusions. DBT combined with discharge care bundles for COPD patients resulted in improvements in disease-specific knowledge, negative emotions, and clinical symptoms with better HRQOL and lower readmission rate.

Prevalence, characteristics, and risk of exacerbation in young patients with chronic obstructive pulmonary disease

Background and objective

Early identification of chronic obstructive pulmonary disease (COPD) in young individuals could be beneficial to attempt preventive interventions. The objective of this study was to investigate clinical features and outcomes of young individuals with COPD from the general population cohort.

Methods

We included individuals from the Korean National Health and Nutrition Examination Survey (KNHANES) with spirometry and identifiable smoking status. Young subjects with COPD were defined as aged between 40 and 50 years and had baseline forced expiratory volume in 1 s [FEV₁]/forced vital capacity [FVC] ratio less than 0.7. Outcomes include the risk of exacerbation and medical expenses during 3 years of follow-up.

Results

Among 2236 individuals aged between 40 and 50 years, 95 (4.2%) had COPD, including 36 who were never-smokers and 59 who were ever-smokers. Approximately 98% of COPD subjects had mild to moderate airflow limitation. Inhaler treatment was given to only 6.3% patients in the COPD group. The risk of exacerbation for a 3-year period was analyzed using the never-smoker, non-COPD group as a comparator. Hazards ratio for exacerbation was 1.60 (95% confidence interval [CI] 0.18–14.20) in the never-smoker COPD group and 1.94 (95% CI 0.31–12.07) in the ever-smoker COPD group of young subjects. COPD related medical costs were not significantly different between non-COPD and COPD groups of young individuals.

Conclusions

The risk of exacerbation showed an increasing trend in COPD patients regardless of smoking status compared to non-COPD. More attention to early identification and provision of preventive measures are needed to reduce disease progression and improve outcome.

Prognosis of Patients with Chronic Obstructive Pulmonary Disease Not Eligible for Major Clinical Trials

Rationale: Randomized controlled trials only include a subset of patients with chronic obstructive pulmonary disease (COPD) fulfilling strict inclusion criteria. Thus, most patients with COPD in a real-world setting do not have the necessary evidence to support treatment effectiveness. Objectives: To test the hypotheses that most individuals with COPD in the general population are not represented in major clinical trials despite clinically significant disease with exacerbations and early death. Methods: In 105,630 adults from a Danish contemporary population-based cohort, we defined COPD as age 40 or more years, chronic respiratory symptoms, history of smoking exposure, and airflow limitation with FEV₁/FVC < 0.70. Outcomes included acute exacerbations and all-cause mortality. Symptomatic smokers without COPD were used as a reference group. Measurements and Main Results: Of all, 7,516 (7%) and 16,079 (15%) were symptomatic smokers with and without COPD. Only 44% of those with COPD were eligible for major clinical trials when applying FEV₁ < 80% predicted, smoking history of 10 or more pack-years, and no comorbid asthma as common inclusion criteria. During the median 8.9 years of follow-up, we observed 2,130 acute exacerbations and 3,973 deaths in symptomatic smokers. Compared with symptomatic smokers without COPD, multivariable-adjusted hazard ratios for exacerbations were 7.45 (95% confidence interval, 5.41-10.3) and 29.0 (21.1-39.8) in those with COPD, respectively, excluded and eligible for clinical trials. Corresponding hazard ratios for all-cause mortality were 1.21 (1.11-1.31) and 1.67 (1.54-1.81), respectively. Conclusions: More than half of individuals with COPD in the general population are excluded from major clinical trials; however, these individuals have a clinically significant disease with exacerbations and early death compared with symptomatic smokers without COPD.

ICU strain and outcome in COVID-19 patients—A multicenter retrospective observational study

Purpose

To compare the characteristics, management, and prognosis of patients admitted to intensive care units (ICU) for coronavirus disease (COVID)-19 during the first two waves of the outbreak and to evaluate the relationship between ICU strain (ICU demand due to COVID-19 admissions) and mortality.

Methods

In a multicentre retrospective study, 1166 COVID-19 patients admitted to five ICUs in France between 20 February and 31 December 2020 were included. Data were collected at each ICU from medical records. A Cox proportional-hazards model identified factors associated with 28-day mortality.

Results

640 patients (55%) were admitted during the first wave (February to June 2020) and 526 (45%) during the second wave (July to December 2020). ICU strain was lower during the second wave (-0.81 [-1.04 –-0.31] vs. 1.18 [-0.34–1.29] SD when compared to mean COVID-19 admission in each center during study period, P<0.001). Patients admitted during the second wave were older, had more profound hypoxemia and lower SOFA. High flow nasal cannula was more frequently used during the second wave (68% vs. 39%, P<0.001) and intubation was less frequent (46% vs. 69%, P<0.001). Neither 28-day mortality (30% vs. 26%, P = 0.12) nor hospital mortality (37% vs. 31%, P = 0.27) differed between first and second wave. Overweight and obesity were associated with lower 28-day mortality while older age, underlying chronic kidney disease, severity at ICU admission as assessed by SOFA score and ICU strain were associated with higher 28-day mortality. ICU strain was not associated with hospital mortality.

Conclusion

The characteristics and the management of patients varied between the first and the second wave of the pandemic. Rather than the wave, ICU strain was independently associated with 28-day mortality, but not with hospital mortality.

Poor Asthma Control in Schoolchildren May Lead to Lower Lung Function Trajectory from Childhood to Early Adulthood: A Japanese Cohort Study

Purpose

Although childhood asthma is a risk factor for adult lung function disorders, the correlation between childhood asthma control level and lung function growth remains unclear in Japan. The correlation between childhood asthma control and early adulthood lung function growth was investigated in this study.

Patients and Methods

We included 505 children with asthma from the Omuta City Air Pollution-Related Health Damage Cohort Program. The characteristics and lung function of girls and boys aged 6–11 years and 12–17 years were compared between poor and good asthma control groups.

Results

Among the 505 children, 214 (42.4%) showed poor asthma control. The mean percentage forced expiratory volume in 1 second predicted for girls and boys aged 6–11 years (80.2% and 79.2%, respectively) and 12–17 years (80.0% and 81.1%, respectively) in the poor control group was significantly lower than those of girls and boys aged 6–11 years (87.9% and 87.3%, respectively) and 12–17 years (88.1% and 87.8%, respectively) in the good control group. However, a linear regression model did not reveal between-group differences in the slopes of lung function growth for both sexes. Girls (24.6%, P < 0.0001) and boys (24.4%, P = 0.0026) in the poor control group had a significantly higher proportion of young adults with obstructive ventilatory patterns than girls (1.4%) and boys (8.1%) in the good control group.

Conclusion

Our findings revealed that poor childhood asthma control leaded to lung function disorders, which suggest the importance of early asthma control in school children.

Association of ambient and household air pollution with lung function in young adults in an peri-urban area of South-India: A cross-sectional study

OBJECTIVE

Although there is evidence for the association between air pollution and decreased lung function in children, evidence for adolescents and young adults is scarce. For a peri-urban area in India, we evaluated the association of ambient PM_2.5 and household air pollution with lung function for young adults who had recently attained their expected maximum lung function.

METHODS

We measured, using a standardized protocol, forced expiratory volume in the first second (FEV₁) and forced vital capacity (FVC) in participants aged 20-26 years from the third follow-up of the population-based APCAPCS cohort (2010-2012) in 28 Indian villages. We estimated annual average PM_2.5outdoors at residence using land-use regression. Biomass cooking fuel (a proxy for levels of household air pollution) was self-reported. We fitted a within-between linear-mixed model with random intercepts by village, adjusting for potential confounders.

RESULTS

We evaluated 1,044 participants with mean age of 22.8 (SD = 1) years (range 20-26 years); 327 participants (31%) were female. Only males reported use of tobacco smoking (9% of all participants, 13% of males). The mean ambient PM_2.5 exposure was 32.9 (SD = 2.8) µg/m³; 76% reported use of biomass as cooking fuel. The adjusted association between 1 µg/m³ increase in PM_2.5 was -27 ml (95% CI, -89 to 34) for FEV₁ and -5 ml (95% CI, -93 to 76) for FVC. The adjusted association between use of biomass was -112 ml (95% CI, -211 to -13) for FEV₁ and -142 ml (95% CI, -285 to 0) for FVC. The adjusted association was of greater magnitude for those with unvented stove (-158 ml, 95% CI, -279 to -36 for FEV₁ and -211 ml, 95% CI, -386 to -36 for FVC).

CONCLUSIONS

We observed negative associations between ambient PM_2.5 and household air pollution and lung function in young adults who had recently attained their maximum lung function.

Reversal of NADPH Oxidase-Dependent Early Oxidative and Inflammatory Responses in Chronic Obstructive Pulmonary Disease by Puerarin

In the present study, we investigated effects of Puerarin on the early oxidative and inflammatory responses in the lung triggered by acute cigarette smoking (ACS). C57BL/6 mice were exposed to ACS for 1 hr in the presence or absence of Puerarin and harvested at 2, 6, and 24 hours. ACS induced significant increases in superoxide production in mouse lungs at 2 and 6 hours; and superoxide production was also elevated in a time and concentration dependent manner in cigarette smoke extract (CSE) stimulated human small airway epithelial cells (HSAECs), which was dose-dependently abrogated by Puerarin. ACS exposure upregulated NOX1, NOX2, and NOX4 protein expression in mouse lungs. Likewise, NOX1 and NOX4 were upregulated in CSE-stimulated HSAECs. These responses were significantly or completely attenuated by Puerarin. ACS induced significant infiltrations of neutrophils and macrophages in mouse lung parenchyma and BAL fluid, which were completely or significantly abrogated by Puerarin, so was the activation of the NF-кB pathway and the upregulation in inflammatory mediators including TNF-α, KC (murine homolog of IL-8), COX-2, IL-6 and MCP-1. Nuclear translocation of p65, IL-8 secretion, and upregulation of COX-2 in CSE stimulated HSAECs were also markedly attenuated by Puerarin. Moreover, ACS or CSE stimulated upregulation in reactive oxygen species (ROS) production and expression of inflammatory mediators were alleviated by ROS scavenger TEMPO in vivo and vitro, with no synergy combining with Puerarin, indicating that the effects of Puerarin are redox-sensitive following activation of NOX. In summary, our data for the first time demonstrate that Puerarin robustly attenuates NOX isoform-dependent ROS production and inflammatory activation in ACS exposed mice and CSE treated HSAECs, indicating that Puerarin might be used as a robust therapeutic agent for early or early stage COPD.

Body Acoustics for the Non-Invasive Diagnosis of Medical Conditions

In the past few decades, many non-invasive monitoring methods have been developed based on body acoustics to investigate a wide range of medical conditions, including cardiovascular diseases, respiratory problems, nervous system disorders, and gastrointestinal tract diseases. Recent advances in sensing technologies and computational resources have given a further boost to the interest in the development of acoustic-based diagnostic solutions. In these methods, the acoustic signals are usually recorded by acoustic sensors, such as microphones and accelerometers, and are analyzed using various signal processing, machine learning, and computational methods. This paper reviews the advances in these areas to shed light on the state-of-the-art, evaluate the major challenges, and discuss future directions. This review suggests that rigorous data analysis and physiological understandings can eventually convert these acoustic-based research investigations into novel health monitoring and point-of-care solutions.

Research Progress on Diaphragm Ultrasound in Chronic Obstructive Pulmonary Disease: A Narrative Review

Chronic obstructive pulmonary disease (COPD) is a common disease of the respiratory system, and its prevalence and mortality remain high. COPD results in continuous impairment of lung function, which severely affects the patient's work and life. In severe cases, there will be acute respiratory failure, which endangers the lives of patients, and respiratory muscle dysfunction is one of the main reasons for this result. As the diaphragm is the most important inspiratory muscle, its dysfunction has a great impact on the deterioration of respiratory function in COPD patients. With the development of ultrasound, more and more studies have found that diaphragm ultrasound can play an important role in the diagnosis and treatment of COPD patients. The main purpose of this article is to review the research progress on diaphragm ultrasound in COPD and briefly introduce diaphragmatic ultrasound examination methods.

10-Year Follow-Up of Lung Function, Respiratory Symptoms, and Functional Capacity in the COPDGene Study

Rationale: The course of lung function, respiratory symptoms, and functional status over time in people who smoke cigarettes is still incompletely understood. The COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease [COPD]) study provides a unique cohort to examine these trajectories, and now 10-year follow-up data are available. Objectives: This study aims to provide insight into the progression of spirometric parameters, respiratory symptoms, and functional capacity over 10 years in current and former cigarette smokers. Methods: We analyzed available longitudinal data for COPDGene participants who did not change smoking status over three visits spanning approximately 10 years of follow-up. Change in postbronchodilator forced expiratory volume in 1 second (FEV1), St. George's Respiratory Questionnaire (SGRQ), and 6-minute walk distance (6MWD) from Phase 1 to Phase 3 were examined using linear mixed models. Terms were included in the models to estimate mean progression separately for current and former cigarette smokers. Models were stratified by baseline Global Initiative for Chronic Obstructive Lung Disease (GOLD) spirometry stages as well as by new 2019 COPDGene classification. Results: The mean age at enrollment of the 9,103 participants in this analysis was 59.8 years (SD = 9.2 yr); 46.4% were women, and 32.6% were African American. In all GOLD COPD groups, including participants with normal spirometry, and all groups categorized by 2019 COPDGene classification, FEV1 decreased, SGRQ increased (indicating higher symptom burden), and 6MWD decreased over the 10-year follow-up period. Current smokers exhibited a greater mean loss of FEV1 over the study period than former smokers for all groups except those with preserved ratio impaired spirometry. For both SGRQ and 6MWD, rates of progression tended to be similar for former and current smokers except for 6MWD in the highest severity groups, in which former smokers had greater progression. However, this could be impacted by some current smokers with faster progression who had quit smoking and were dropped from analyses. Conclusions: Progression in FEV1, SGRQ, and 6MWD overall appears to be slow, and the change over time in groups traditionally characterized as not having disease closely mirrors that of the groups with COPD at all GOLD stages. Current cigarette smokers had greater loss of FEV1 than former smokers, whereas SGRQ and 6MWD changes were more similar between current and former cigarette smokers.

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.

Nasal High Flow Therapy For Symptom Management in People Receiving Palliative Care

For patients with chronic non-malignant lung disease, severe chronic breathlessness can significantly impact quality of life, causing significant disability, distress, social isolation, and recurrent hospital admissions. Caregivers for people with challenging symptoms, such as severe breathlessness, are also profoundly impacted. Despite increasing research focused on breathlessness over recent years, this symptom remains extremely difficult to manage, with no effective treatment that completely relieves breathlessness. A new potential treatment for relieving breathlessness in patients at home is nasal high flow (NHF) therapy. NHF therapy is a respiratory support system that delivers heated, humidified air (together with oxygen if required) with flows of up to 60 L/min. This case describes a patient with very severe chronic obstructive pulmonary disease who received domiciliary NHF therapy (approximately 8 hours/day, flow rate of 20 L/min) over twelve months with good effect for the relief of severe chronic breathlessness. We discuss the management principles for severe chronic breathlessness, the physiological effects of NHF therapy and the evidence for long-term use in the community setting. With the support of respiratory and palliative care clinicians together, domiciliary NHF therapy has great potential for improving current symptom management approaches in people with life-limiting illnesses.

Mmp12 Is Upregulated by in utero Second-Hand Smoke Exposures and Is a Key Factor Contributing to Aggravated Lung Responses in Adult Emphysema, Asthma, and Lung Cancer Mouse Models

Matrix metalloproteinase-12 (Mmp12) is upregulated by cigarette smoke (CS) and plays a critical role in extracellular matrix remodeling, a key mechanism involved in physiological repair processes, and in the pathogenesis of emphysema, asthma, and lung cancer. While cigarette smoking is associated with the development of chronic obstructive pulmonary diseases (COPD) and lung cancer, in utero exposures to CS and second-hand smoke (SHS) are associated with asthma development in the offspring. SHS is an indoor air pollutant that causes known adverse health effects; however, the mechanisms by which in utero SHS exposures predispose to adult lung diseases, including COPD, asthma, and lung cancer, are poorly understood. In this study, we tested the hypothesis that in utero SHS exposure aggravates adult-induced emphysema, asthma, and lung cancer.

Methods: Pregnant BALB/c mice were exposed from gestational days 6–19 to either 3 or 10mg/m³ of SHS or filtered air. At 10, 11, 16, or 17weeks of age, female offspring were treated with either saline for controls, elastase to induce emphysema, house-dust mite (HDM) to initiate asthma, or urethane to promote lung cancer. At sacrifice, specific disease-related lung responses including lung function, inflammation, gene, and protein expression were assessed.

Results: In the elastase-induced emphysema model, in utero SHS-exposed mice had significantly enlarged airspaces and up-regulated expression of Mmp12 (10.3-fold compared to air-elastase controls). In the HDM-induced asthma model, in utero exposures to SHS produced eosinophilic lung inflammation and potentiated Mmp12 gene expression (5.7-fold compared to air-HDM controls). In the lung cancer model, in utero exposures to SHS significantly increased the number of intrapulmonary metastases at 58weeks of age and up-regulated Mmp12 (9.3-fold compared to air-urethane controls). In all lung disease models, Mmp12 upregulation was supported at the protein level.

Conclusion: Our findings revealed that in utero SHS exposures exacerbate lung responses to adult-induced emphysema, asthma, and lung cancer. Our data show that MMP12 is up-regulated at the gene and protein levels in three distinct adult lung disease models following in utero SHS exposures, suggesting that MMP12 is central to in utero SHS-aggravated lung responses.

Focus on Early COPD: Definition and Early Lung Development

Chronic obstructive pulmonary disease (COPD) is a disease with high incidence rate and mortality rates worldwide. It is the third leading cause of death in the world. Nevertheless, little progress has been made in treating and preventing the disease. Under these circumstances, the concept of “early COPD” was proposed. Although this concept is not new, most health-care workers do not fully understand early COPD and tend to confuse it with mild COPD. In this review, we mainly discuss the definition of early COPD and the developmental trajectory of lung function. Although patients with early COPD have no symptoms, their lung function is already lower than that of normal people. A relatively complete definition is needed to identify this group of people. Reduced lung function is the diagnostic criterion for COPD, but lung development is a long-term dynamic process. In addition to smoking and air pollution, we should pay more attention to prenatal and childhood risk factors, for example, parents smoking, birth weight, preterm birth, mode of delivery, childhood respiratory infections and childhood asthma. Health-care workers need to be fully aware of early COPD, to reduce the morbidity of COPD and take effective measures to prevent these risk factors.

Carnitine Palmitoyltransferase System: A New Target for Anti-Inflammatory and Anticancer Therapy?

Lipid metabolism involves multiple biological processes. As one of the most important lipid metabolic pathways, fatty acid oxidation (FAO) and its key rate-limiting enzyme, the carnitine palmitoyltransferase (CPT) system, regulate host immune responses and thus are of great clinical significance. The effect of the CPT system on different tissues or organs is complex: the deficiency or over-activation of CPT disrupts the immune homeostasis by causing energy metabolism disorder and inflammatory oxidative damage and therefore contributes to the development of various acute and chronic inflammatory disorders and cancer. Accordingly, agonists or antagonists targeting the CPT system may become novel approaches for the treatment of diseases. In this review, we first briefly describe the structure, distribution, and physiological action of the CPT system. We then summarize the pathophysiological role of the CPT system in chronic obstructive pulmonary disease, bronchial asthma, acute lung injury, chronic granulomatous disease, nonalcoholic fatty liver disease, hepatic ischemia–reperfusion injury, kidney fibrosis, acute kidney injury, cardiovascular disorders, and cancer. We are also concerned with the current knowledge in either preclinical or clinical studies of various CPT activators/inhibitors for the management of diseases. These compounds range from traditional Chinese medicines to novel nanodevices. Although great efforts have been made in studying the different kinds of CPT agonists/antagonists, only a few pharmaceuticals have been applied for clinical uses. Nevertheless, research on CPT activation or inhibition highlights the pharmacological modulation of CPT-dependent FAO, especially on different CPT isoforms, as a promising anti-inflammatory/antitumor therapeutic strategy for numerous disorders.

The novel bronchodilator navafenterol: a phase 2a, multi-centre, randomised, double-blind, placebo-controlled crossover trial in COPD

Background

Navafenterol (AZD8871) belongs to a new class of bronchodilator, the single-molecule muscarinic antagonist and β-agonist, developed for the treatment of COPD. This study aimed to evaluate the efficacy, pharmacokinetics and safety of navafenterol versus placebo and an active comparator treatment for moderate-to-severe COPD.

Methods

This phase 2a, randomised, multicentre (Germany and UK), double-blind, double-dummy, three-way complete crossover study (ClinicalTrials.gov identifier: NCT03645434) compared 2 weeks’ treatment of once-daily navafenterol 600 µg via inhalation with placebo and a fixed-dose combination bronchodilator (umeclidinium/vilanterol (UMEC/VI); 62.5 µg/25 µg) in participants with moderate-to-severe COPD. The primary outcome was change from baseline in trough forced expiratory volume in 1 s (FEV₁) on day 15. Secondary end-points included change from baseline in peak FEV₁; change from baseline in Breathlessness, Cough and Sputum Scale (BCSS); change from baseline in COPD Assessment Tool (CAT); adverse events; and pharmacokinetics.

Results

73 participants were randomised. After 14 days, trough FEV₁ was significantly improved with navafenterol compared with placebo (least-squares (LS) mean difference 0.202 L; p<0.0001). There was no significant difference in FEV₁ between navafenterol and UMEC/VI (LS mean difference −0.046 L; p=0.075). COPD symptoms (CAT and BCSS) showed significantly greater improvements with both active treatments versus placebo (all p<0.005). Novel objective monitoring (VitaloJAK) showed that cough was reduced with both active treatments compared with placebo. Safety profiles were similar across the treatment groups and no serious adverse events were reported in the navafenterol treatment period.

Conclusion

Once-daily navafenterol was well tolerated, improved lung function and reduced COPD-related symptoms, similar to an established once-daily fixed-dose combination bronchodilator.

Navafenterol, a novel dual-pharmacology bronchodilator for COPD, improved lung function, reduced COPD symptoms and decreased objective cough counts, to a similar extent to umeclidinium/vilanterolhttps://bit.ly/3lV886y

The Association between Chronic Heroin Smoking and Chronic Obstructive Pulmonary Disease

INTRODUCTION

Little is known about the correlation between chronic obstructive pulmonary disease (COPD) and heroin smoking. Heroin smoking is a recent underinvestigated problem. The goal of this study is to study the impact of heroin smoking among COPD patients.

METHODS

This is a descriptive clinical study. A combination of self-reporting questionnaires and data extraction tools were used to collect information during baseline tests, interviews, and follow-ups. Patients' medical, clinical, and socioeconomic history were recorded. Participants were recruited using random sampling from multiple centers.

RESULTS

Out of 1034 COPD patients, heroin smokers represented the vast majority of addiction cases (n = 133). Heroin smokers were leaner than non-addicts (19.78 ± 4.07 and 24.01 ± 5.6, respectively). The most common type of comorbidities among heroin smokers was emphysema (27%). Both the forced expiratory volume (FEV₁)/forced vital capacity ratio and FEV1% predicted were lower among heroin smokers than non-addicts (52.79 ± 12.71 and 48.54 ± 14.38, respectively). The majority of heroin smokers (55%) had advanced COPD, and at least 15% of heroin smokers suffered from frequent respiratory failure. The mean ± SD for COPD onset age among heroin smokers was 44.23 ± 5.72, and it showed a statistically significant correlation (P < 0.001).

CONCLUSION

Heroin smoking might be linked to the onset of COPD. Heroin smokers showed a significantrespiratory impairment compared to tobacco smokers of the same age group.

Effectiveness of a Motivational Nutritional Intervention through Social Networks 2.0 to Increase Adherence to the Mediterranean Diet and Improve Lung Function in Active Smokers: The DIET Study, a Randomized, Controlled and Parallel Clinical Trial in Primary Care

BACKGROUND

Diet can help preserve lung function in smokers, as well as aid individuals who avoid smoking. This study aimed to evaluate the effectiveness of a nutritional intervention, using the Social Networks 2.0 tool, to increase adherence to the Mediterranean diet (MD) and improve lung function in smokers without prior respiratory disease.

METHODS

A randomized controlled parallel design was used. The participants were assigned to either the intervention or control group. Data from representative smokers without respiratory disease (n = 77) aged 18-70 years were analyzed. The participants completed a validated semi-quantitative food-frequency questionnaire, and their adherence to the diet was evaluated by using the questionnaire called the Mediterranean Diet Adherence Score (MEDAS, with 14 items), which considers ≥9 points to indicate high adherence. The lung function was assessed by spirometry. Associations among variables were determined by logistic regression.

RESULTS

A comparison of the variables at the end of the study between the control and intervention groups showed that the intervention significantly increased adherence to the MD based on the MEDAS questionnaire (0.69 (2.1) vs. 2.05 (2.03); p = 0.009). Specifically, the consumption of fruits was increased after two years in both groups; however, a more significant increase was detected in the intervention group (121 (178) vs. 12.7 (167) in the control group; p-value = 0.008). In the unadjusted analysis, the intervention only showed a statistical significant increase in the score of adherence to the MD (β: 1.36; 95% CI 0.35; 2.3; p = 0.009), and this increase was maintained after adjusting for age and sex (β: 1.15; 95% CI 0.05; 2.2; p = 0.040) and after adjusting for various sociodemographic, lifestyle and anthropometric variables (β: 1.17; 95% CI 0.02; 2.31; p = 0.046). The pulmonary function parameters improved more in the intervention group; however, no significant differences were observed between the two groups.

CONCLUSIONS

A nutritional intervention based on a dietetic-nutritional education program resulted in a significant increase in adherence to the MD. However, some evidence suggests that an MD dietary intervention can improve lung function, but in our study, we were not able to demonstrate this. Further research is needed to obtain more robust data and confirm a possible benefit of the program before it can be extended to general practice.

Measurement of the Total Lung Volume Using an Adjusted Single-Breath Helium Dilution Method in Patients With Obstructive Lung Disease

Background: Whole-body plethysmography (WBP) is the gold standard for measuring lung volume, but its clinical application is limited as it requires expensive equipment and is not simple to use. Studies have shown that the single-breath helium dilution (SBHD) method, which is commonly used in clinical practice, significantly underestimates lung volume in patients with obstructive lung disease (OLD). By comparing the differences in lung volume measured using SBHD and WBP, we aimed to establish a correction equation for the SBHD method to determine the total lung volume in patients with OLD of different severities.

Methods: From 628 patients with OLD simultaneously subjected to SBHD and WBP, 407 patients enrolled between January 2018 and November 2019 were in the training group and 221 enrolled between December 2019 and December 2020 were in the prospective verification cohort. The multiple linear regression equation was used for data in the training group to establish a correction equation for SBHD to determine the total lung volume, and this was validated in the prospective validation cohort.

Results: There was a moderate positive correlation between total lung capacity (TLC) determined using the SBHD [TLC (SBHD)] and WBP methods [TLC (WBP)] (r = 0.701; P < 0.05), and the differences between TLC (SBHD) and TLC (WBP) (ΔTLC) were related to the severity of obstruction. As the severity of obstruction increased, the TLC was underestimated by the SBHD method. We established the following correction equation: TLC (adjusted SBHD) (L) = −0.669 + 0.756*TLC(SBHD)(L) – 0.047*FEV1FVC+0.039*height (cm)–0.009*weight(kg)(r2 = 0.753 and adjusted r2 = 0.751). Next, we validated this equation in the validation cohort. With the correction equation, no statistical difference was observed between TLC (adjusted SBHD) and TLC (WBP) among the obstruction degree groups (P > 0.05).

Conclusions: The SBHD method is correlated with WBP to measure the total lung volume, but the SBHD method presents limitations in determining the total lung volume in patients with obstructive lung disease. Here, we established an effective and reliable correction equation in order to accurately assess the total lung volume of patients with OLD using the SBHD method.