Lung-Function Trajectories Leading to Chronic Obstructive Pulmonary Disease

Increased plasma interleukin-1β is associated with accelerated lung function decline in non-smokers

Interleukin-1β is one of the major cytokines involved in the initiation and persistence of airway inflammation in chronic obstructive pulmonary disease (COPD). However, the association between plasma interleukin-1β and lung function decline remains unclear. We aimed to explore the association between plasma interleukin-1β and lung function decline. This longitudinal evaluation of data from the Early COPD study analysed the association between the plasma interleukin-1β concentration, lung function decline, and COPD exacerbation. Overall, 1,328 participants were included in the baseline analysis, and 1,135 (85%) completed the 1-year follow-up. Increased plasma interleukin-1β was associated with accelerated lung function decline in non-smokers (forced expiratory volume in 1 s: per unit natural log-transformed increase, adjusted unstandardised β [95% confidence interval] 101.46 [16.73-186.18] mL/year, p=0.019; forced vital capacity: per unit natural log-transformed increase, adjusted unstandardised β [95% confidence interval] 146.20 [93.65-198.75] mL/year, p<0.001), but not in smokers. In non-smokers, participants with an interleukin-1β concentration in the top 30% (>5.02 pg/mL) had more respiratory symptoms, more severe emphysema and air trapping, and higher levels of inflammation-related biomarkers. In this study, a subgroup with increased plasma interleukin-1β was identified among non-smokers, and increased plasma interleukin-1β was associated with lung function accelerated decline.

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.

Histopathology of the small airways: Similarities and differences between ageing and COPD

Age-related lung function decline is associated with small airway closure and gas trapping. The mechanisms which cause these changes are not fully understood. It has been suggested that COPD is caused by accelerated ageing. We have investigated pathological changes in the small airways during ageing, and evaluated whether the same or different processes exist in COPD. Histopathology and immunohistochemistry were used to examine small airway remodelling in healthy ageing, and then compare to age matched COPD patients. Ageing was associated with reduced alveolar attachment numbers (rho= -0.4 p = 0.049), increased epithelial area (rho = 0.5 p = 0.01), greater luminal narrowing due to epithelial expansion (rho = 0.5 p = 0.04) and increased alveolar septal neutrophils (rho = 0.6 p = 0.005). Compared to age matched controls, COPD small airways had 31% less alveolar attachments per airway (p = 0.02) and significantly more alveoalr septal neutrophils (p = 0.0007). Increased airway wall thickness was a feature of COPD but was not related to ageing in non-smokers. Alveolar attachment loss, accompanied by alveolar septum neutrophilic inflammation, and increased luminal narrowing due to epithelial expansion are major features of small airway remodelling during ageing. These features can explain the increased small airway narrowing and closure during ageing. Alveolar attachment loss is accelerated in COPD, likely due to increased neutrophilic inflammation.

Childhood respiratory risk profiles associate with lung function and COPD among the old population

BACKGROUND

Childhood, often characterized by multiple concurrent risk factors, holds significant influence over long-term respiratory outcomes, with the intricate interplay among these factors representing an intriguing but underexplored avenue for research. We aimed to determine if respiratory risk factors during childhood affect lung function and chronic obstructive pulmonary disease (COPD) in old age.

METHODS

Participants were drawn from the Health and Retirement Study cohort. Latent class analysis (LCA) was applied with six variables used to develop the early-life respiratory risk profiles. Linear regressions and logistic regressions were used to assess the associations between childhood respiratory risk profiles and lung function, including peak expiratory flow (PEF) value, PEF value <80% of the predicted value and COPD.

RESULTS

A total of 12,296 participants (5017 males and 7279 females) with an average age of 68 years were recruited. We identified six distinct childhood respiratory risk profiles: (1) 'Asthma and respiratory disorders in early childhood' (n = 241, 1.96%), (2) 'Unexposed or least exposed' (n = 3874, 31.51%), (3) 'Smokers at home' (n = 7609, 61.88%), (4) 'Ear problems and respiratory disorders in early childhood' (n = 162, 1.32%), (5) 'Allergic conditions and respiratory disorders in early childhood' (n = 220, 1.79%) and (6) 'Allergic conditions and respiratory disorders in later childhood' (n = 190, 1.55%). Profile 2 served as the reference. The highest reduction of PEF was seen for profile 1 (-30.07 L/min), followed by profile 6 (-22.24 L/min) and profile 5 (-18.47 L/min). Profile 6, profile 3 and profile 1 related to 1.98-, 1.52- and 1.66-fold increased risks of diminished PEF values, respectively. The highest risk of COPD was observed in profile 5 (aOR = 4.16, 95% CI: 3.75-4.57), followed by profile 6 (aOR = 4.10, 3.69-4.51), profile 4 (aOR = 3.70, 3.25-4.15), profile 1 (aOR = 3.46, 3.07-3.85) and profile 3 (aOR = 1.41, 1.25-1.57).

CONCLUSIONS

People exposed to early-life respiratory challenges experienced larger declines in lung function and increased risks of COPD later in life. Our findings underscore the importance of early-life respiratory health in shaping lung function trajectories.

Temporal Exploration of Chronic Obstructive Pulmonary Disease Phenotypes: Insights from the COPDGene and SPIROMICS Cohorts

Rationale: Chronic obstructive pulmonary disease (COPD) exhibits considerable progression heterogeneity. We hypothesized that elastic principal graph analysis (EPGA) would identify distinct clinical phenotypes and their longitudinal relationships. Objectives: Our primary objective was to create a map of COPD phenotypes and their connectivity using EPGA. Secondarily, we used longitudinal and external data sets to test the validity and reproducibility of this map. Methods: Cross-sectional data from 8,972 tobacco-exposed COPDGene participants, with and without COPD, were used to train a model with EPGA, using thirty clinical, physiologic and CT features. 4,585 participants from COPDGene Phase 2 were used to test longitudinal trajectories. 2,652 participants from SPIROMICS tested external reproducibility. Measurements and Main Results: Our analysis used cross-sectional data to create an elastic principal tree, where time is associated with distance on the tree. Six clinically distinct tree segments were identified that differed by lung function, symptoms, and CT features: Subclinical (SC); Parenchymal Abnormality (PA); Chronic Bronchitis (CB); Emphysema Male (EM); Emphysema Female (EF); and Severe Airways (SA) disease. 5-year data from COPDGene mapped longitudinal changes onto the tree, and longitudinal trajectories demonstrated a net flow of patients from SC towards EM and EF, including trajectories through airway disease predominant phenotypes, CB and SA. Cross-sectional SPIROMICS data projected onto the tree showed clinically similar patient groupings. Conclusions: This novel analytic methodology provides an approach to defining longitudinal phenotypic trajectories using cross sectional data. These insights are clinically relevant and could facilitate precision therapy and future trials to modify disease progression. Clinical trial registered with www.clinicaltrials.gov (NCT00608764 and NCT01969344).

Immunotherapeutic targeting of aging-associated isoDGR motif in chronic lung inflammation

Accumulation of damaged biomolecules in body tissues is the primary cause of aging and age-related chronic diseases. Since this damage often occurs spontaneously, it has traditionally been regarded as untreatable, with typical therapeutic strategies targeting genes or enzymes being ineffective in this domain. In this report, we demonstrate that an antibody targeting the isoDGR damage motif in lung tissue can guide immune clearance of harmful damaged proteins in vivo, effectively reducing age-linked lung inflammation. We observed age-dependent accumulation of the isoDGR motif in human lung tissues, as well as an 8-fold increase in isoDGR-damaged proteins in lung fibrotic tissues compared with healthy tissue. This increase was accompanied by marked infiltration of CD68+/CD11b + macrophages, consistent with a role for isoDGR in promoting chronic inflammation. We therefore assessed isoDGR function in mice that were either naturally aged or lacked the isoDGR repair enzyme. IsoDGR-protein accumulation in mouse lung tissue was strongly correlated with chronic inflammation, pulmonary edema, and hypoxemia. This accumulation also induced mitochondrial and ribosomal dysfunction, in addition to features of cellular senescence, thereby contributing to progressive lung damage over time. Importantly, treatment with anti-isoDGR antibody was able to reduce these molecular features of disease and significantly reduced lung pathology in vivo.

Nomogram to predict progression from preserved ratio impaired spirometry to chronic obstructive pulmonary disease

Preserved Ratio Impaired Spirometry (PRISm) is a specific subtype of pre-chronic obstructive pulmonary disease (pre-COPD). People with PRISm are at risk of progression to chronic obstructive pulmonary disease (COPD). We developed a model to predict progression in subjects with PRISm. We screened 188 patients whose lung function transitioned from PRISm to COPD and 173 patients with PRISm who remained stable over two years. After excluding 78 patients due to incomplete clinical or laboratory data, a total of 283 patients were included in the final analysis. These patients were randomly divided into a training cohort (227 patients) and a validation cohort (56 patients) at a 8:2 ratio. LASSO regression and multivariate logistic regression were used to identify factors influencing progression. Among the 283 patients, 134 progressed to COPD. The model developed using six variables showed good performance, with areas under the receiver operating characteristic (ROC) curves of 0.87 in the training cohort and 0.79 in the validation cohort. The model demonstrated excellent calibration and was clinically meaningful, as shown by decision curve analysis (DCA) and clinical impact curve (CIC). We developed China's first prediction model for the progression of lung function from PRISm to COPD in a real-world population. This model is conducive to early identification of high-risk groups of pulmonary function deterioration, so as to provide timely intervention and delay the occurrence and progression of the disease.

Prevalence of chronic obstructive pulmonary disease in high-risk populations at low, intermediate, high altitudes: a population based cross-sectional study in Yunnan Province, China

BACKGROUND

Chronic obstructive pulmonary disease (COPD) represents a significant public health challenge. This study aimed to investigate the epidemiological characteristics of COPD across different altitudes and evaluate the potential influence of altitude on its prevalence of high-risk populations.

METHODS

This cross-sectional study employed a multi-stage randomized cluster sampling method and enrolled 11,095 adult residents aged ≥ 20 years at different elevations in Yunnan Province, China. Screening questionnaires identified high-risk individuals among participants, who then underwent pulmonary function tests. COPD was diagnosed based on post-bronchodilator test results. We utilized multivariate logistic regression models to examine the association between altitudes and COPD prevalence while controlling for demographic variables, lifestyle factors, and disease characteristics.

RESULTS

A total of 2,252 (20.3%) were in the high-risk group. The prevalence of COPD in high-risk populations increased with age across low, intermediate, and high altitude areas. COPD patients in high-risk populations at high-altitude areas had a higher prevalence of ethnic minorities and significant biomass fuel exposure. Conversely, the proportion of COPD patients in the severe stages (GOLD III-IV) was notably lower in high-altitude regions. Logistic regression models revealed COPD prevalence in high-risk populations at high altitudes to be significantly lower than at low altitudes, with odds ratios of 0.538(95% CI: 0.343-0.844), 0.470(95% CI: 0.289-0.766), and 0.518 (95% CI: 0.316-0.848) for Models 1, 2, and 3, respectively (all P < 0.05).

CONCLUSION

The prevalence of COPD in high-risk populations is the lowest in the high-altitude regions of Yunnan Province, and high altitude is an independent factor negatively associated with COPD.

Nonlinear association between serum 25-hydroxyvitamin D concentrations and lung function in the United States adult population with COPD

Vitamin D has been studied for its potential protective effects against lung function decline in patients with COPD. However, conflicting results exist, the actual effect of vitamin D on lung function remains controversial. This study aimed to determine whether serum 25-hydroxyvitamin D (25-OHD) levels are correlated with lung function in community-dwelling individuals with COPD. We used data from the National Health and Nutrition Examination Survey (NHANES) to explore the relationship between serum 25-OHD concentration and the severity of airflow obstruction. Multivariable logistic regression, stratified analysis with interaction, restricted cubic splines (RCS), and threshold effect analysis were used to investigate the association between serum 25-OHD concentration and lung function.A total of 1384 patients with COPD were analyzed. Accordingly, the association between serum 25-OHD concentrations and lung function exhibited an inverse L-shaped curve in the RCS. Threshold analysis showed that in participants with 25-OHD concentrations < 90 nmol/L, lung function decreased with decrease in serum 25-OHD concentrations, whereas no significant association was observed in those with serum 25-OHD concentrations ≥ 90 nmol/L. An inverse L-shaped relationship was observed between serum 25-OHD concentration and airflow obstruction severity in the adult population with COPD in the United States.

Trajectories of airflow limitation from childhood to early adulthood: an analysis of six population-based birth cohorts

BACKGROUND

Lung function during childhood is an important predictor of subsequent health and disease. Understanding patterns of lung function and development of airflow limitation through childhood is necessary to inform lung function trajectories in relation to health and chronic airway disease. We aimed to derive trajectories of airflow limitation from childhood (age 5-8 years) into early adulthood (age 20-26 years) using repeated spirometry data from birth cohorts.

METHODS

In this study, we drew forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) data from six population-based birth cohorts: the UK-based Avon Longitudinal Study of Parents and Children (ALSPAC), Isle of Wight cohort (IOW), Manchester Asthma and Allergy Study (MAAS), and Aberdeen Study of Eczema and Asthma (SEATON) as well as the Swedish Child (Barn), Allergy, Milieu, Stockholm, Epidemiological survey (BAMSE) and the Dutch Prevention and Incidence of Asthma and Mite Allergy (PIAMA) cohort. For the discovery analysis, we pooled data from ALSPAC, IOW, MAAS, and BAMSE with spirometry data recorded at middle childhood (age 8-10 years), adolescence (age 15-18 years), and early adulthood (age 20-26 years). For the replication analysis, we pooled middle childhood and adolescence spirometry data from PIAMA and SEATON. We used latent class trajectory modelling to derive trajectory classes based on joint modelling of FEV1 and FEV1/FVC ratio regression residuals ascertained from all age groups. The final model was selected using the lowest Bayesian information criterion. Participants were assigned to the trajectory with the highest posterior probability. Weighted random-effect multinomial logistic regression models were used to investigate factors associated with joining each trajectory, the results of which are reported as relative risk ratios (RRRs) with 95% CIs.

FINDINGS

The discovery population included 8114 participants: 4710 from ALSPAC, 808 from IOW, 586 from MAAS, and 2010 from BAMSE and was modelled into one of four lung function trajectories that showed normal airflow (6555 [80·8%] of 8114 people), persistent airflow obstruction (1280 [15·8%]), worsening airflow obstruction (161 [2·0%]), and improved airflow obstruction (118 [1·5%]). Both improvement in and worsening airflow obstruction by early adulthood were seen from all initial severity levels. Whereas improvement in airflow obstruction was more prominent between middle childhood and adolescence (57·8%) than between adolescence and early adulthood (13·4%), worsening airflow obstruction was more prominent between adolescence and early adulthood (61·5%) than between middle childhood and adolescence (32·6%). Among current wheezers, higher BMI was associated with a lower relative risk of joining the trajectory with improvement in airflow obstruction (RRR 0·69 [95% CI 0·49-0·95]), whereas among non-wheezers, higher BMI increased the relative risk of being in the improved airflow obstruction trajectory (1·38 [1·04-1·85]). A higher BMI at first lung function assessment was associated with a higher relative risk of joining the trajectory for improvement in airflow obstruction trajectory in participants with low birthweight and no current asthma diagnosis (RRR 2·44 [1·17-5·12]); by contrast, higher BMI is associated with a lower relative risk of joining the trajectory with improvement in airflow obstruction among those with low birthweight and current asthma diagnosis (0·37 [0·18-0·76]). Results in replication cohorts (n=1337) were consistent with those in the discovery cohort.

INTERPRETATION

Worsening and improvement in airflow limitation from school age to adulthood might occur at all ages and all airflow obstruction severity levels. Interventions to optimise healthy weight, including tackling overweight and obesity (particularly among children with wheezing) as well as treating underweight among non-wheezers, could help to improve lung health across the lifespan.

FUNDING

UK Medical Research Council and CADSET European Respiratory Society Clinical Research Collaboration.

Pulmonary function tests in the neonatal intensive care unit and beyond: a clinical review

Pulmonary function tests (PFTs) in the Neonatal Intensive Care Unit (NICU) have played a pivotal role in neonatal care. They have helped quantify the effects of therapeutic interventions, guide ventilator management, and serve as endpoints in clinical trials. Preterm delivery, the most common cause of altered lung development, establishes early lung function trajectories that persist into later life. Early PFTs in preterm infants can enhance our understanding of factors influencing these trajectories. This review summarizes techniques performed in the NICU and early infancy and the evolution of continuous lung function monitoring through the bedside ventilator. It provides examples incorporating PFTs in the NICU and early infancy to improve outcomes and identifies evolving technology in this area. This review does not include studies of control of breathing in newborn infants. Looking ahead, the field would greatly benefit from developing a sustainable, non-invasive PFT technique that can be applied across the lifespan.

The treatment responses among different inhalation therapies for GOLD group E patients with chronic obstructive pulmonary disease

Background

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2023 revised the combined chronic obstructive pulmonary disease (COPD) assessment, merging groups C and D into group E, and revised the initial inhalation therapy recommendation. We aimed to evaluate the treatment responses among different inhalation therapies in GOLD group E patients stratified by the COPD assessment test (CAT) scores and forced expiratory volume in one-second percentage of predicted (FEV1%pred).

Methods

In this retrospective cohort study, we included patients with COPD registered in the Real World Research of Diagnosis and Treatment of COPD (RealDTC) study between January 2017 and June 2023. According to the GOLD 2023 report, we enrolled patients assigned to GOLD group E based on exacerbations in the past year (≥2 exacerbations or ≥1 hospitalisation) in this study. We classified them into the FEV1%pred <50% and FEV1%pred ≥50% groups, or CAT<10 and CAT≥10 groups. Subsequently, we divided all groups into four subgroups: long-acting muscarinic antagonist (LAMA), long-acting β2-agonist (LABA) + inhaled corticosteroid (ICS), LABA + LAMA, and LABA + LAMA + ICS. All patients finished one year of follow-up, during which we collected data on exacerbations, frequent exacerbations, hospitalisations, and all-cause mortality. We defined frequent exacerbations as ≥2 exacerbations per year.

Results

We enrolled a total of 3173 patients in this study. During one year of follow-up, there were no significant differences in exacerbations, frequent exacerbations, hospitalisations, and all-cause mortality among LAMA, LABA + LAMA, LABA + ICS, and LABA + LAMA + ICS in the FEV1%pred ≥50% and CAT<10 groups. However, the patients treated with LABA + LAMA or LABA + LAMA + ICS had a lower incidence of exacerbations and frequent exacerbations compared with the patients treated with LAMA or LABA + ICS in the FEV1%pred <50% and CAT≥10 groups (P < 0.05).

Conclusions

Patients with COPD in GOLD group E should be further stratified to determine the appropriate initial inhalation therapy. This approach may provide more precise treatment for GOLD group E patients.

Lung function-associated exposome profile in the era of climate change: Pooled analysis of 8 population-based European cohorts within the EXPANSE project

BACKGROUND

The independent and interrelated long-term effects of the exposome such as air pollution, greenness, and ambient temperature on lung function are not well understood, yet relevant in the light of climate change.

METHODS

Pre-bronchodilation FEV1 from five mature birth cohorts (N = 4724) and three adult cohorts (N = 6052) from five European countries were used to assess cross-sectional associations with air pollution, greenness, and ambient temperature, assigned to their residential address. All two-way interactions and square terms were a priori included in building the final elastic net regression model. Elastic net regression results were put into the context of different environmental scenarios such as improvement of air quality, improvement of greenness, climate change, or their combinations.

RESULTS

Elastic net regression of FEV1 z-scores identified non-zero coefficients for many interaction terms, indicating the importance of joint effects of exposure to air pollution, greenness, and temperature. The non-zero coefficients were bigger and more stable in adults than in children. Upon exploring lung function benefits for different environmental scenarios, an improvement of FEV1 was expected in the scenario of improving air quality or greenness. In contrast, negative changes in FEV1 z-scores were expected in the scenario of climate change, characterized by daily temperature increase in summer and decrease in winter. The beneficial FEV1 effects of improving air pollution or greenness were attenuated in the presence of climate change.

CONCLUSION

Complex exposome profiles of long-term exposure to air pollution, greenness, and temperature showed associations with FEV1 in European adults, and to less extent in children and adolescents. Climate change seems to have a negative impact on lung function and modifies the association of air pollution and greenspace with lung function.

Asthma and respiratory comorbidities

Asthma is a common respiratory condition with various phenotypes, nonspecific symptoms, and variable clinical course. The occurrence of other respiratory conditions with asthma, or respiratory comorbidities (RCs), is not unusual. A literature search of PubMed was performed for asthma and a variety of respiratory comorbidities for the years 2019 to 2024. The 5 conditions with the largest number of references, other than rhinitis and rhinosinusitis (addressed elsewhere), or that are the most problematic in the authors' clinical experience, are summarized. Others are briefly discussed. The diagnosis and treatment of both asthma and RCs are complicated by the overlap of symptoms and signs. Recognizing RCs is especially problematic in adult-onset, non-type 2 asthma because there are no biomarkers to assist in confirming non-type 2 asthma. Treatment decisions in subjects with suspected asthma and RCs are complicated by the potential similarities between the symptoms or signs of the RC and asthma, the absence of a sine quo non for the diagnosis of asthma, the likelihood that many RCs improve with systemic corticosteroid therapy, and the possibility that manifestations of the RCs are misattributed to asthma or vice versa. Recognition of RCs is critical to the effective management of asthma, particularly severe or difficult-to-treat asthma.

Breastfeeding and Lung Function of Children: A Systematic Review and Meta-Analysis

AIM

To evaluate the associations between breastfeeding and lung function among children without known respiratory diseases and to determine the effects of breastfeeding on spirometry.

METHODS

A systematic search of PubMed, Embase and Cochrane was performed from their inception to 11 Oct 2023 (PROSPERO identifier: CRD42023471664). Observational studies (cohort or cross-sectional or case-control design) and randomised controlled trials (RCTs) were searched. A random-effects model meta-analysis was used to estimate the effect size if significant heterogeneity was detected (p < 0.05 or I2 > 50%); Otherwise, the fixed-effects model was applied.

RESULTS

In total, 13 observational studies with 18 152 children were included in the qualitative synthesis, and five studies with 5305 children were included in the meta-analysis. Compared to children who were never breastfed, those who were breastfed had better FEV1 (β: 19.34 mL; 95% CI: 6.05, 32.64; p = 0.004) and PEF (β: 87.50 mL/s; 95% CI: 27.43, 147.58; p = 0.004). A similar trend was observed for FVC (β: 17.45 mL; 95% CI: -0.43, 35.33; p = 0.06). Furthermore, compared to children breastfed for less than three to four months, those breastfed for three to four months or more had better FEV1 (β: 19.86 mL; 95% CI: 4.21, 35.51; p = 0.01), FVC (β: 31.90 mL; 95% CI: 7.87, 55.93; p = 0.009) and PEF (β: 75.68 mL/s; 95% CI: 24.40, 126.97; p = 0.004).

CONCLUSION

This systematic review and meta-analysis revealed associations between breastfeeding and improved lung function in children aged 6-16 years. Further high-quality evidence is needed.

Longitudinal Changes in Maximal Forced Inspiratory Flow and Clinical Outcomes in Patients With COPD

BACKGROUND

COPD primarily impairs expiratory flow due to progressive airflow obstruction and reduced lung elasticity. Increasing evidence underlines the importance of inspiratory flow as a biomarker for selecting inhaler devices and providing ancillary aerodynamic information.

RESEARCH QUESTION

Do the longitudinal changes in maximum forced inspiratory flow (FIFmax) influence acute exacerbations and lung function decline in patients with COPD?

STUDY DESIGN AND METHODS

This longitudinal study evaluated FIFmax in patients with COPD over a 7-year period from 2004 to 2020. Eligible patients were categorized into two groups based on FIFmax trajectory: the increased FIFmax group and the decreased FIFmax group. The study assessed the annual rate of acute exacerbations and the annual decline rate of FEV1. Subgroup analyses were conducted based on treatment status, with a focus on inhaled therapy and inhaler device usage.

RESULTS

Among the eligible 956 patients with COPD, 56.5% belonged to the increased FIFmax group. After propensity score matching, the increased FIFmax group experienced lower rates of severe exacerbations (0.16 per year vs 0.25 per year, P = .017) and a slower decline in FEV1 (0 [interquartile range, -51 to 71] mL/y vs -43 [interquartile range, -119 to 6] mL/y; P < .001) compared with the decreased FIFmax group. These associations were particularly prominent in patients using specific inhaler therapies such as dry powder inhalers.

INTERPRETATION

This study showed that the longitudinal changes in FIFmax are associated with clinical outcomes in patients with COPD. Patients with increased FIFmax experienced a lower rate of severe exacerbations and a slower decline in lung function. These findings suggest the potential benefits of optimizing inspiratory flow in COPD management, although further studies are needed to confirm these observations due to potential confounding factors.

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.

Enlarged airspaces in the distal lung in adolescents born very preterm as measured by aerosol

RATIONALE

Preterm infants diagnosed with bronchopulmonary dysplasia (BPD) are thought to have fewer and larger alveoli than their term peers, but it is unclear to what degree this persists later in life.

OBJECTIVES

To investigate to what degree the distal airspaces are enlarged in adolescents born preterm and to evaluate the new Airspace Dimension Assessment (AiDA) method in investigating this group.

METHODS

We investigated 41 adolescents between 15 and 17 years of age, of whom 25 were born very preterm (a gestational age <31 weeks, with a mean of 26 weeks) and 16 were term-born controls. Of the preterms, 17 were diagnosed with BPD. The AiDA method was used to measure the average distal airspace radius (rAiDA) in the lungs. In addition, lung function was evaluated by spirometry, impulse oscillometry and diffusing capacity of carbon monoxide (DLCO).

MEASUREMENTS AND MAIN RESULTS

We observed a mean rAiDA of 295±53 µm for the preterm group compared with 231±12 µm for the control group (p<0.0001). The adolescents diagnosed with BPD had a mean rAiDA of 313±54 µm. There was a strong negative correlation between gestational age and distal airspace radius (p<0.0001). The BPD group had a decreased FEV1 (forced expiratory volume in 1 s, z-score: -1.28±1.37, p=0.012) and DLCO (z-score: -0.92±1.01, p=0.013) compared with the controls, but all other lung function variables showed normal values.

CONCLUSIONS

Our results suggest that the enlarged airspaces seen in preterm infants likely remain in adolescence. Distal airspace radius as measured by AiDA was the lung function variable that showed the most significant difference between preterm and term-born adolescents.

Dysanapsis Genetic Risk Predicts Lung Function Across the Lifespan

Rationale: Dysanapsis refers to a mismatch between airway tree caliber and lung size arising early in life. Dysanapsis assessed by computed tomography (CT) is evident by early adulthood and associated with chronic obstructive pulmonary disease (COPD) risk later in life. Objectives: By examining the genetic factors associated with CT-assessed dysanapsis, we aimed to elucidate its molecular underpinnings and physiological significance across the lifespan. Methods: We performed a genome-wide association study of CT-assessed dysanapsis in 11,951 adults, including individuals from two population-based and two COPD-enriched studies. We applied colocalization analysis to integrate genome-wide association study and gene expression data from whole blood and lung. Genetic variants associated with dysanapsis were combined into a genetic risk score that was applied to examine association with lung function in children from a population-based birth cohort (n = 1,278) and adults from the UKBiobank (n = 369,157). Measurements and Main Results: CT-assessed dysanapsis was associated with genetic variants from 21 independent signals in 19 gene regions, implicating HHIP (hedgehog interacting protein), DSP, and NPNT as potential molecular targets based on colocalization of their expression. A higher dysanapsis genetic risk score was associated with obstructive spirometry among 5-year-old children and among adults in the fifth, sixth, and seventh decades of life. Conclusions: CT-assessed dysanapsis is associated with variation in genes previously implicated in lung development, and dysanapsis genetic risk is associated with obstructive lung function from early life through older adulthood. Dysanapsis may represent an endophenotype link between the genetic variations associated with lung function and COPD.

Long-Term Outcome of Childhood Asthma: Characterizing COPD-A and COPD-C Subtypes in Adulthood

Background and Aim

Asthma in early life has been linked to subsequent development of COPD and according to GOLD 2023 COPD may be divided into distinct subtypes. We aimed to investigate factors associated with the GOLD classification COPD-A (asthma in childhood) and COPD-C (tobacco exposure) in a cohort of adults with a history of severe childhood asthma.

Patients and Methods

In a cohort of Danish adults with a history of severe childhood asthma and a previous 4-month stay during childhood at the asthma care facility in Kongsberg, Norway, we divided participants in a long-term follow-up examination into COPD-A and COPD-C, defined as post-bronchodilator FEV1/FVC < 0.7, and never-smoker or ever-smoker, respectively, and no airflow limitation. Characteristics between groups were analysed.

Results

The study cohort comprised 232 adults with a history of severe childhood asthma, of whom 30 (13%) and 23 (10%), respectively, were classified as COPD-A and COPD-C. Compared to those with no airflow limitation, individuals with COPD-A and COPD-C more often had had at least one exacerbation (filled prescription of oral corticosteroid) in the past 12 months (risk ratio [RR] 1.83 and 2.65, respectively). The COPD-C group had a significantly higher Medical Research Council dyspnoea score (p<0.01) and significantly higher blood eosinophil count (p<0.01) than those with no airflow limitation. Compared to the COPD-C group, the COPD-A group had higher fractional exhaled nitric oxide (mean 29 [SD 28]) and FEV1%pred (mean 75 [SD 20]). Finally, when comparing participants with COPD-A to both COPD-C and participants without airflow limitation, the proportion of participants with osteoporosis (17%) and depression (10%) was more than twice as high.

Conclusion

Our study revealed a high prevalence and unique features of the two COPD subtypes COPD-A and COPD-C in a cohort of adults with a history of severe childhood asthma.

Lung function in adult patients with osteogenesis imperfecta: a cohort study

BACKGROUND

Osteogenesis imperfecta (OI) is a rare hereditary bone disease resulting from a defect in collagen synthesis or processing, leading to bone fragility, frequent fractures and skeletal deformities. OI is associated with increased respiratory morbidity and mortality, but the mechanisms of lung involvement are poorly understood, and there are no data on the natural history of lung function. We studied lung function over time in a cohort of adult OI patients at one center.

METHODS

We used data from OI patients aged 15 and above followed up at the Lausanne university hospital between 2012 and 2023 with available pre-bronchodilator spirometry. Associations between spirometric measurements at first visit and clinical characteristics were studied through linear regression. Changes of spirometric variables over time were analysed through mixed linear regression. Models were adjusted for age, sex, height and OI type (Sillence classification).

RESULTS

Among 46 subjects, 24% had impaired spirometry at baseline, with similar distribution between restrictive (8.7%), obstructive (8.7%) and mixed (6.5%) ventilatory patterns. At first visit, higher age was associated with lower FEV1 (β = -0.019 l, p = 0.014) and lower FEV1/FVC (β = -0.175%, p = 0.012). A history of asthma was associated with higher FEV1 (β = 0.636 l, p = 0.028) and FVC (β = 0.834 l, p = 0.010). At first visit, FEV1 (β = -0.750 l, p = 0.006) and FVC (β = -0.859 l, p = 0.004) was lower in individuals with OI Sillence types 3, 4 or 5 compared to type 1. Over a mean follow-up of 3.4 years, smokers had a greater decline of FEV1/FVC compared to non-smokers (β = -6.592%, p = 0.007). Individuals with a mutation in the gene COL1A2 had 740 ml lower FVC compared to those with a mutation in COL1A1 (p = 0.037). After adjustment for sex, age, height and OI type, FEV1 increased by 26 ml (95% CI 8; 45) or 1.28%pred (0.51; 2.05) and FVC increased by 25 ml (95% CI 8; 43) or 0.93%pred (0.31; 1.55) per year of follow-up.

CONCLUSIONS

An increase of FEV1 and FVC over time was observed in OI patients after adjustment for other variables, suggesting that the defective collagen synthesis may impact the pulmonary interstitium and lead to increased lung compliance and hyperinflation, in contrast to skeletal deformities, which reduce the thoracic volume. Lung function changes in OI thus result from the interplay of several mechanisms.

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.

Duration and Frequency of Spirometry Needed to Accurately Reflect Annualized Change of FEV1 in Chronic Obstructive Pulmonary Disease

Rationale: The slope of decline in forced expiratory volume in 1 second (FEV1) is commonly used to reflect the rate of disease progression for descriptive studies and therapeutic trials in chronic obstructive pulmonary disease (COPD). The frequency and duration of spirometric testing needed to report the true slope are unknown. Objectives: We sought to define the minimum frequency and follow-up duration needed to accurately describe the annualized rate of FEV1 change among patients with moderate to very severe COPD. Methods: We performed a post hoc analysis of the annualized rate of FEV1 change among 4,412 subjects previously enrolled in the 4-year Understanding Potential Long-Term Impacts on Function with Tiotropium-or, UPLIFT-trial of tiotropium versus placebo. Slope estimates were modeled for different iterations of semiannual or annual testing over a variable duration up to 42 months. All models were compared with a reference of semiannual spirometry for 42 months. Results: The overall annual rate of postbronchodilator FEV1 decline measured semiannually for 42 months (44.6 ml; 95% confidence interval [CI] = 42.5-46.6) did not differ significantly from annual spirometry over the same period (43.7 ml; 95% CI = 41.3-46.1) or semiannual spirometry over the first 2 years (44.3 ml; 95% CI = 41.1-47.5). Agreement was consistent for two follow-up values as far as 24 months apart (43.3 ml; 95% CI = 39.9-46.8). Models that are based on less than two follow-up values or a duration less than 18 months were characterized by relative underestimation of the slope. Conclusions: In a large cohort of patients with moderate to very severe COPD, the annualized rate of change in FEV1 was accurately represented by a minimum of two annual follow-up measurements over 18 months compared with semiannual testing over 42 months.

Does lung function in preschoolers help to predict asthma in later life?

The earliest respiratory function assessments, within or close to the neonatal period, consistently show correlations with lung function and with the development of asthma into adulthood. Measurements of lung function in infancy reflect the in utero period of lung development, and if early enough, show little influence of postnatal environmental exposures. Later in the preschool and school age periods, influences of the environment are superimposed on initial levels. Fetal exposures before birth such as maternal smoking during pregnancy, lead to reduced lung function and an increased risk of asthma in females particularly those with certain glutathione S-transferase genotypes. Lung function measurements later in the preschool period are also associated with development of asthma. Although lung function in preschoolers does help predict asthma in later life and these observations have increased our understanding of the physiology underlying asthma, the findings have not led to thewidespread use of lung function measurements being in preschoolers as clinical predictors of asthma due to the practicalities of testing in this age group.

Application research on asthma-COPD overlap using low-dose CT scan and quantitative analysis

PURPOSE

The aim of this study was to assess the proximal airway remodeling, emphysema, and air trapping of asthma-COPD Overlap.

MATERIALS AND METHODS

20 ACO patients, 55 mild to moderate COPD patients and 38 non-severe asthma patients were participated in low-dose dual phase CT scanning and pulmonary function test, comparative analysis was performed to identify differences in CT measurements among three groups.

RESULTS

(Ⅰ) The average age and smoking index of ACO and mild to moderate COPD were both higher than non-severe asthma. ACO and mild to moderate COPD group had a higher proportion of males than non-severe asthma. (Ⅱ) In terms of pulmonary function test, FEV1 (%Pred), FEV1/FVC%, MEF25% (%Pred), MEF 50% (%Pred), MMEF (%Pred), and PEF (%Pred) in ACO were significantly reduced than those in non-severe asthma. (Ⅲ) On proximal airway parameters, ACO exhibited higher WA% and Pi10 compared to mild to moderate COPD. However, there was no statistically significant difference in WA% and Pi10 between ACO and non-severe asthma. (Ⅳ) On CT lung function, the emphysema index VI-910ex of ACO was significantly higher than non-severe asthma.Additionally, ACO demonstrated higher MLDex and VI-856ex compared to non-severe asthma.

CONCLUSIONS

Compared with non-severe asthma, ACO is more common in male patients with older age and a longer history of smoking, which had more severe airflow obstruction and airway dysfunction than non-severe asthma.ACO showed more obvious proximal airway remodeling than mild to moderate COPD, and was more similar to non-severe asthma.The extent of emphysema and air trapping in ACO were more pronounced compared to non-severe asthma.

Prediction of spirometry outcome in Croatian patients with chronic obstructive pulmonary disease

The current study offers an extensive examination of the influence of 29 diverse parameters on spirometry measurement variables in a cohort of 534 patients with chronic obstructive pulmonary disease (COPD) from five different centers in Croatia. The study elucidates both the magnitude and direction of the effect exerted by the 29 predictors on forced vital capacity (FVC), forced expiratory volume in one second (FEV1), the ratio FEV1/FVC, and predicted forced expiratory flow at 50% of FVC. Additionally, the development of prediction models for these parameters has been undertaken using several statistical methods. The study identifies fat-free mass index, 6-minute walk distance, predicted diffusing capacity of the lung for carbon monoxide, arterial partial pressure of oxygen, and both arterial and tissue hemoglobin oxygen saturation percentage as robust positive predictors for all four spirometry parameters. Body mass index is recognized as a weak positive predictor for FEV1 and FEV1/FVC, commonly observed in COPD patients. As expected, smoking years is identified as a strong negative predictor for all four spirometry parameters, while age and illness duration exhibit strong predictive negative associations. Furthermore, modified medical research council, arterial partial pressure carbon dioxide, St George's respiratory questionnaire, COPD assessment test, depression anxiety stress scales, and nutritional risk screening are identified as weak negative predictors. Charlson comorbidity index, phase angle, and number of comorbidities do not exhibit a significant impact on spirometry variables. Ultimately, the performed factorial analysis categorized the 29 parameters into five groups, which were identified as relating to lung function, health status, nutritional status, age, and smoking. Multiple regression analysis, including four newly derived parameters based on the results of factorial analysis, identified nutritional status as a positive predictor for spirometry readings, while smoking, poor health status, and age were identified as negative predictors in successive order.

Maternal Glycemia During Pregnancy and Child Lung Function: A Prospective Cohort Study

OBJECTIVE

Gestational diabetes mellitus (GDM) is known to be associated with certain respiratory impairments in offspring. However, the specific association between maternal GDM and childhood lung function remains unclear. We examined the association of maternal glycemia, as measured by oral glucose tolerance test (OGTT) values, with childhood lung function outcomes in a birth cohort.

RESEARCH DESIGN AND METHODS

A follow-up study was conducted with 889 children aged 6 years whose mothers underwent a 75-g OGTT between 24 and 28 weeks of gestation. After adjusting for prenatal and postnatal factors, multivariable regression models were used to evaluate the relationship between maternal glycemia and offspring lung function.

RESULTS

In total, 10.7% of the offspring were exposed to maternal GDM. Maternal GDM significantly reduced the z score of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and forced expiratory flow at 25-75% of FVC in children, with more pronounced effects in female offspring. Maternal 1- and 2-h post-OGTT glucose z scores and the sum of those z scores, but not those for fasting glucose, were inversely associated with several measures of children's lung function. Additionally, maternal GDM increased the risk of impaired lung function in children (odds ratio 2.64; 95% CI, 1.10-5.85), defined as an FVC <85% of the predicted value. There were no significant associations with FEV1/FVC.

CONCLUSIONS

Maternal hyperglycemia was negatively associated with lung function in children, particularly among girls. Further studies are warranted to elucidate the underlying mechanisms of this association and to explore potential interventions to mitigate its effects.

Association between measures of kidney function and preserved ratio impaired spirometry in diabetes: NHANES 2007-2012

OBJECTIVES

This study aimed to examine the relationship between measures of kidney function and impaired lung function in individuals with diabetes and to assess all-cause mortality risk associated with having chronic kidney disease (CKD) and or impaired lung function.

DESIGN

Cross-sectional and retrospective cohort study.

SETTING

The National Health and Nutrition Examination Survey 2007-2012.

PARTICIPANTS

A total of 10 809 participants aged over 20 years were included in this study: 9503 with normal spirometry, 951 with preserved ratio impaired spirometry (PRISm) and 355 with variable obstruction (VO).

EXPOSURE AND OUTCOME MEASURES

Kidney function measures, including estimated glomerular filtration rate (eGFR) and urinary albumin to creatinine ratio (UACR), were considered exposure variables. PRISm and VO were outcome variables. PRISm was defined as a forced expiratory volume in 1 s (FEV1)<80% predicted and an FEV1/forced vital capacity (FVC) ratio≥0.7, while VO was defined as an FEV1/FVC ratio <0.7 prebronchodilator and ≥0.7 postbronchodilator. In the cross-sectional analysis, multivariate logistic regression models were used to assess the relationship between kidney function measures and spirometry findings. In the retrospective cohort analysis, Cox proportional hazards models were employed to evaluate the impact of having PRISm or VO, combined with CKD, on all-cause mortality.

RESULTS

An increase in UACR was significantly associated with higher odds of PRISm (OR (95% CI)=1.10 (1.01, 1.21), p=0.03). Additionally, eGFR <60 was associated with the odds of variable obstructive lung function (OR (95% CI)=1.72 (1.07, 2.74), p=0.03) compared with eGFR >60. After adjustments, an increase in UACR was associated with higher odds of PRISm in individuals with diabetes (OR (95% CI)=1.21 (1.08, 1.36), p=0.002), and UACR ≥300 mg/g significantly increased odds of having PRISm in idividuals with diabetes (OR (95% CI)=2.34 (1.23, 4.47), p=0.01). During a mean follow-up of 12.3 years, 10 500 deaths occurred. In the diabetic group, compared with normal spirometry without CKD, those with both PRISm and CKD had a significantly increased risk of all-cause mortality (HR (95% CI)=3.46 (1.94, 6.16), p<0.0001).

CONCLUSION

An elevated UACR and albuminuria were linked to a higher risk of PRISm. Our study emphasises that kidney and lung function are correlated. Further research is necessary to confirm our findings.

Prevalence and etiotypes of persistent airflow obstruction in the general population across the lifetime

BACKGROUND AND OBJECTIVES

Different factors (etiotypes) can lead to persistent airflow obstruction (PAO) across the lifetime, including genetic factors, abnormal lung development, cigarette smoking, traffic pollution exposure, respiratory infections and asthma. Here we explore the prevalence of PAO and associated etiotypes in the general population in different age bins.

METHODS

We studied 664 individuals with PAO (FEV1/FVC post bronchodilation (post-BD) below the lower limit of normal (LLN)) and 11,522 with normal lung function (FEV1/FVC, FEV1 and FVC ≥ LLN and ≤ upper limit of normal (ULN) post-BD) included in the LEAD Study (NCT01727518), a general population cohort in Vienna (Austria). For analysis, participants were stratified in three age bins (<25, 25-<50 and ≥ 50 years of age).

RESULTS

PAO occurred in 3.8 % in females and 5.6 % in males of the cohort, and it increased with age. Most participants with PAO (57.5 %) reported respiratory symptoms, indicating a high burden of disease. PAO was associated with male sex (25-<50 years), ever smoking (>50 years), increased number of pack years (25-<50 years, >50 years), not being breastfed (<25 years) and ever diagnosis of asthma (in all age bins). Etiotypes varied by age bins with cigarette smoking being the most prevalent one, often in combination with traffic pollution exposure.

CONCLUSION

In the general population PAO occurs in about 5 % of participants with a higher prevalence in older individuals. Etiotypes and associated factors for PAO accumulate with age.

Lung imaging in COPD and asthma

Chronic obstructive pulmonary disease (COPD) and asthma are common lung diseases with heterogeneous clinical presentations. Lung imaging allows evaluations of underlying pathophysiological changes and provides additional personalized approaches for disease management. This narrative review provides an overview of recent advances in chest imaging analysis using various modalities, such as computed tomography (CT), dynamic chest radiography, and magnetic resonance imaging (MRI). Visual CT assessment localizes emphysema subtypes and mucus plugging in the airways. Dedicated software quantifies the severity and spatial distribution of emphysema and the airway tree structure, including the central airway wall thickness, branch count and fractal dimension of the tree, and airway-to-lung size ratio. Nonrigid registration of inspiratory and expiratory CT scans quantifies small airway dysfunction, local volume changes and shape deformations in specific regions. Lung ventilation and diaphragm movement are also evaluated on dynamic chest radiography. Functional MRI detects regional oxygen transfer across the alveolus using inhaled oxygen and ventilation defects and gas diffusion into the alveolar-capillary barrier tissue and red blood cells using inhaled hyperpolarized 129Xe gas. These methods have the potential to determine local functional properties in the lungs that cannot be detected by lung function tests in patients with COPD and asthma. Further studies are needed to apply these technologies in clinical practice, particularly for early disease detection and tailor-made interventions, such as the efficient selection of patients likely to respond to biologics. Moreover, research should focus on the extension of healthy life expectancy in patients at higher risk and with established diseases.

Associations between psychosocial stress, child's anxiety, and lung function in mid-childhood

BACKGROUND

Reducing the risk of respiratory disease during the plastic stages of lung development could have long-term health impacts. Psychosocial stress has been previously linked to adverse childhood respiratory outcomes, but the influence of child's anxiety and sex differences has not been completely elucidated.

OBJECTIVE

To evaluate the association among maternal stress, child anxiety, and lung function in children and to explore differences by sex.

METHODS

Cross-sectional analyses included 294 mother-child pairs from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) birth cohort in Mexico City. Children's lung function was tested once at ages 8 to 13 years of age, and height- and sex-adjusted z-scores were estimated for forced vital capacity, forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity and forced expiratory flow between 25% and 75%. Maternal stress was assessed through the Crisis in Family Systems-Revised (CRISYS-R) survey, used to report negative life events experienced in the past 6 months and dichotomized at the median (<3 and ≥3). Child's self-reported anxiety was assessed using the Revised Children's Manifest Anxiety Scale short form and dichotomized at the clinically relevant cutoff (T-score ≥ 60). The association among maternal stress, child anxiety, and lung function outcomes was evaluated using linear models. Effect modification by sex was evaluated with interaction terms and in stratified analyses.

RESULTS

We did not find any association between maternal stress and any lung function outcome. Clinically elevated child anxiety symptoms were associated with lower forced expiratory volume in 1 second (β = -0.36, 95% CI -0.69 to -0.02). We found no evidence of effect modification by sex.

CONCLUSION

Results highlight the importance of considering childhood mental health in relation to lung function outcomes.

Exploring the link between the pediatric exposome, respiratory health, and executive function in children: a narrative review

Asthma is a highly prevalent inflammatory condition, significantly affecting nearly six million U.S. children and impacting various facets of their developmental trajectories including neurodevelopment. Evidence supports a link between pediatric environmental exposures in two key areas: asthma and executive function (E.F.). E.F.s are a collective of higher-order cognitive processes facilitating goal-oriented behaviors. Studies also identify asthma-associated E.F. impairments in children. However, limited research has evaluated the inter-relationships among environmental exposures, asthma, and E.F. in children. This review explored relevant research to identify and connect the potential mechanisms and pathways underlying these dynamic associations. The review suggests that the role of the pediatric exposome may function through (1) several underlying biological pathways (i.e., the lung-brain axis, neuroendocrine system, and hypoxia), which could drive asthma and maladaptive E.F. in children and (2) the relationships between the exposome, asthma, and E.F. is a bidirectional linkage. The review reveals essential synergistic links between asthma and E.F. deficits, highlighting the potential role of the pediatric exposome.

CT Radiomics Features Predict Change in Lung Density and Rate of Emphysema Progression

Rationale Emphysema progression is heterogeneous. Predicting temporal changes in lung density and detecting rapid progressors may facilitate selection of individuals for targeted therapies. Objective To test whether computed tomography (CT) radiomics can be used to predict changes in lung density and detect rapid progressors. Methods We extracted radiomics features from inspiratory chest CT in 4,575 subjects with and without airflow obstruction at enrollment, who completed a follow-up visit at approximately 5 years. We quantified emphysema using adjusted lung density (ALD) and estimated emphysema progression as the annualized change in ALD (∆ALD/year) between visits. We categorized participants into rapid progressors (>1% ∆ALD/year) and stable disease (≤1% ∆ALD/year). A gradient boosting model was used (1) to predict ALD at 5-years and (2) to identify rapid progressors. Four models using demographics (base clinical model); CT density; radiomics; and combined features (clinical, radiomics, and CT density) were evaluated and tested. Results There were 1,773 (38.8%) rapid progressors. For predicting ALD at 5-years in the 20% held-out data, the base model explained 31% of the variance (adjusted R2 = 0.31) whereas R2 was 0.74 for the CT density model, 0.66 for the radiomics-only model, and 0.77 for the combined features model. For detecting rapid progressors, the base model (AUC = 0.57, 95%CI 0.53-0.61) was outperformed by the radiomics-only model (AUC = 0.73, 95%CI 0.69-0.76, ∆ =0.0003, p < 0.001) and the combined model (AUC = 0.74, 95%CI 0.71-0.77, ∆ = 0.0003, p < 0.001). Conclusions Parenchymal and airway radiomics features derived from inspiratory scans can be used to predict temporal changes in lung density and help identify rapid progressors.

Estimating rate of lung function change using clinical spirometry data

RATIONALE

In chronic obstructive pulmonary disease (COPD), accurately estimating lung function from electronic health record (EHR) data would be beneficial but requires addressing complexities in clinically obtained testing. This study compared analytic methods for estimating rate of forced expiratory volume in one second (FEV1) change from EHR data.

METHODS

We estimated rate of FEV1 change in patients with COPD from a single centre who had ≥3 outpatient tests spanning at least 1 year. Estimates were calculated as both an absolute mL/year and a relative %/year using non-regressive (Total Change, Average Change) and regressive (Quantile, RANSAC, Huber) methods. We compared distributions of the estimates across methods focusing on extreme values. Univariate zero-inflated negative binomial regressions tested associations between estimates and all-cause or COPD hospitalisations. Results were validated in an external cohort.

RESULTS

Among 1417 participants, median rate of change was approximately -30 mL/year or -2%/year. Non-regressive methods frequently generated erroneous estimates due to outlier first measurements or short intervals between tests. Average change yielded the most extreme estimates (minimum=-3761 mL/year), while regressive methods, and Huber specifically, minimised extreme estimates. Huber, Total Change and Quantile FEV1 slope estimates were associated with all-cause hospitalisations (Huber incidence rate ratio 0.98, 95% CI 0.97 to 0.99, p<0.001). Huber estimates were also associated with smoking status, comorbidities and prior hospitalisations. Similar results were identified in an external validation cohort.

CONCLUSIONS

Using EHR data to estimate FEV1 rate of change is clinically applicable but sensitive to challenges intrinsic to clinically obtained data. While no analytic method will fully overcome these complexities, we identified Huber regression as useful in defining an individual's lung function change using EHR data.

Childhood physical inactivity and excess weight: Two potentially modifiable risk factors for COPD

See related article

Predictors of lung function in early adulthood: A population-based cohort study

BACKGROUND AND OBJECTIVE

Lung function reaches a peak/plateau in early adulthood before declining with age. Lower early adult lung function may increase the risk for chronic obstructive pulmonary disease (COPD) in mid-late adult life. Understanding the effects of multiple childhood/adolescent exposures and their potential interactions on plateau lung function would provide insights into the natural history of COPD.

METHODS

Longitudinal spirometry data from 688 participants with complete data from a population-based birth cohort (original n = 1037) were used to investigate associations between a wide range of childhood/adolescent exposures and repeated measures of FEV1, FVC and FEV1/FVC during the early-adult plateau phase. Generalized estimating equations were used to accommodate the multiple timepoints per participant.

RESULTS

FEV1 reached a peak/plateau between ages 18 and 26 and FVC from 21 to 32 years, whereas FEV1/FVC declined throughout early adulthood. Childhood asthma and airway hyperresponsiveness were associated with lower early adult FEV1 and FEV1/FVC. Smoking by age 18 was associated with lower FEV1/FVC. Higher BMI during early adulthood was associated with lower FEV1 and FVC and lower FEV1/FVC. Physical activity during adolescence was positively associated with FEV1 and FEV1/FVC but this was only statistically significant in men. There was no convincing evidence of interactions between exposures.

CONCLUSION

Childhood asthma and airway hyperresponsiveness are associated with lower lung function in early adulthood. Interventions targeting these may reduce the risk of COPD in mid-late adult life. Promotion of physical activity during adolescence, prevention of cigarette smoking and maintenance of a healthy body weight in early adulthood are also priorities.

Early menopause and hormone therapy as determinants for lung health outcomes: a secondary analysis using the PLCO trial

RATIONALE

Early natural menopause (early-M; <45 years of age) increases the risk of lung morbidities and mortalities in smokers. However, it is largely unknown whether early-M due to surgery demonstrates similar effects and whether menopausal hormone therapy (MHT) is protective against lung diseases.

OBJECTIVES

To assess the associations of early-M and MHT with lung morbidities and mortalities using the prospective Prostate, Lung, Colorectal and Ovarian (PLCO) trial.

METHODS

We estimated the risk among 69 706 postmenopausal women in the PLCO trial, stratified by menopausal types and smoking status.

RESULTS

Early-M was associated with an increased risk of most lung disease and mortality outcomes in ever smokers with the highest risk seen for respiratory mortality (HR 1.98, 95% CI 1.34 to 2.92) in those with bilateral oophorectomy (BO). Early-M was positively associated with chronic bronchitis, and all-cause, non-cancer and respiratory mortality in never smokers with natural menopause or BO, with the highest risk seen for BO- respiratory mortality (HR 1.91, 95% CI 1.16 to 3.12). Ever MHT was associated with reduced all-cause, non-cancer and cardiovascular mortality across menopause types regardless of smoking status and was additionally associated with reduced risk of non-ovarian cancer, lung cancer (LC) and respiratory mortality in ever smokers. Among smokers, ever MHT use was associated with a reduction in HR for all-cause, non-cancer and cardiovascular mortality in a duration-dependent manner.

CONCLUSIONS

Smokers with early-M should be targeted for smoking cessation and LC screening regardless of menopause types. MHT users had a lower likelihood of dying from LC and respiratory diseases in ever smokers.

Epigenome-Wide Association Studies of Chronic Obstructive Pulmonary Disease and Lung Function: A Systematic Review

Rationale: Chronic obstructive pulmonary disease (COPD) results from gene-environment interactions over the lifetime. These interactions are captured by epigenetic changes, such as DNA methylation. Objectives: To systematically review the evidence form epigenome-wide association studies related to COPD and lung function. Methods: A systematic literature search performed on PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases identified 1,947 articles that investigated epigenetic changes associated with COPD and/or lung function; 17 of them met our eligibility criteria, from which data were manually extracted. Differentially methylated positions (DMPs) and/or annotated genes were considered replicated if identified by two or more studies with a P < 1 × 10-4. Measurements and Main Results: Ten studies profiled DNA methylation changes in blood and seven in respiratory samples, including surgically resected lung tissue (n = 3), small airway epithelial brushings (n = 2), BAL (n = 1), and sputum (n = 1). Main results showed: 1) high variability in study design, covariates, and effect sizes, which prevented a formal meta-analysis; 2) in blood samples, 51 DMPs were replicated in relation to lung function and 12 related to COPD; 3) in respiratory samples, 42 DMPs were replicated in relation to COPD but none in relation to lung function; and 4) in COPD versus control studies, 123 genes (2.6% of total) were shared between one or more blood and one or more respiratory samples and associated with chronic inflammation, ion transport, and coagulation. Conclusions: There is high heterogeneity across published COPD and/or lung function epigenome-wide association studies. A few genes (n = 123; 2.6%) were replicated in blood and respiratory samples, suggesting that blood can recapitulate some changes in respiratory tissues. These findings have implications for future research. Systematic Review [protocol] registered with Open Science Framework (OSF).

Risk of incident chronic obstructive pulmonary disease during longitudinal follow-up in patients with nontuberculous mycobacterial pulmonary disease

BACKGROUND

The Global Initiative for Chronic Obstructive Lung Disease 2023 revision proposed that chronic obstructive pulmonary disease (COPD) has various etiologies including infections (COPD-I), such as tuberculosis and human immunodeficiency virus. While nontuberculous mycobacterial pulmonary disease (NTM-PD) and pulmonary tuberculosis share similar clinical manifestations, research on COPD development during longitudinal follow-up in patients with NTM-PD is limited. In this study, we aimed to evaluate the incidence and risk of COPD development in patients with NTM-PD.

METHODS

We retrospectively enrolled patients with NTM-PD with normal lung function and 1:4 age-, sex-, body mass index-, and smoking status-matched controls between November 1994 and January 2022. We compared the risks of spirometry-defined COPD between the NTM-PD and control groups (study 1). A nationwide cohort study using the health insurance claims database was conducted to validate the findings (study 2).

RESULTS

In study 1, during a mean follow-up of 3.3 years, COPD occurred in 14.0% (241/1,715) and 4.3% (293/6,860) of individuals in the NTM-PD and matched control cohorts, respectively. The NTM-PD cohort exhibited a higher risk of incident COPD (adjusted hazard ratio [aHR], 2.57; 95% CI, 2.15-3.09) compared to matched controls. In study 2, COPD occurred in 6.2% (24/386) and 2.5% (28/1,133) of individuals with and without NTM-PD, respectively. The NTM-PD cohort had a higher risk of incident COPD (aHR, 2.04; 95% CI, 1.21-3.42) compared to matched controls.

CONCLUSION

These findings suggest that NTM-PD could be considered a new etiotype of COPD-I and emphasize the importance of monitoring lung function in individuals with NTM-PD.

It is high time to discard a cut-off of 0.70 in the diagnosis of COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) has traditionally been diagnosed based on the criterion of an FEV1/FVC <0.70. However, this definition has limitations as it may only detect patients with later-stage disease, when pathologic changes have become irreversible. Consequently, it potentially omits individuals with early-stage disease, in whom the pathologic changes could be delayed or reversed.

AREAS COVERED

This narrative review summarizes recent evidence regarding early-stage COPD, which may not fulfill the spirometric criteria but nonetheless exhibits features of COPD or is at risk of future COPD progression.

EXPERT OPINION

A comprehensive approach, including symptoms assessment, various physiologic tests, and radiologic features, is required to diagnose COPD. This approach is necessary to identify currently underdiagnosed patients and to halt disease progression in at- risk patients.

Exploring the genetics of airflow limitation in lung function across the lifespan - a polygenic risk score study

Background

Chronic obstructive pulmonary disease (COPD) is caused by interactions between many factors across the life course, including genetics. A proportion of COPD may be due to reduced lung growth in childhood. We hypothesized that a polygenic risk score (PRS) for COPD is associated with lower lung function already in childhood and up to adulthood.

Methods

A weighted PRS was calculated based on the 82 association signals (p ≤ 5 × 10-8) revealed by the largest GWAS of airflow limitation (defined as COPD) to date. This PRS was tested in association with lung function measures (FEV1, FVC, and FEV1/FVC) in subjects aged 4-50 years from 16 independent cohorts participating in the Chronic Airway Diseases Early Stratification (CADSET) Clinical Research Collaboration. Age-stratified meta-analyses were conducted combining the results from each cohort (n = 45,406). These findings were validated in subjects >50 years old.

Findings

We found significant associations between the PRS for airflow limitation and: (1) lower pre-bronchodilator FEV1/FVC from school age (7-10 years; β: -0.13 z-scores per one PRS z-score increase [-0.15, -0.11], q-value = 7.04 × 10-53) to adulthood (41-50 years; β: -0.16 [-0.19, -0.13], q-value = 1.31 × 10-24); and (2) lower FEV1 (from school age: 7-10 years; β: -0.07 [-0.09, -0.05], q-value = 1.65 × 10-9, to adulthood: 41-50 years; β: -0.17 [-0.20, -0.13], q-value = 4.48 x 10-20). No effect modification by smoking, sex, or a diagnosis of asthma was observed.

Interpretation

We provide evidence that a higher genetic risk for COPD is linked to lower lung function from childhood onwards.

Funding

This study was supported by CADSET, a Clinical Research Collaboration of the European Respiratory Society.

Asthma-COPD overlap and asthma progressing to COPD: Are we using the right diagnostic approaches and pathways?

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The lung extracellular matrix protein landscape in severe early-onset and moderate chronic obstructive pulmonary disease

Extracellular matrix (ECM) remodeling has been implicated in the irreversible obstruction of airways and destruction of alveolar tissue in chronic obstructive pulmonary disease (COPD). Studies investigating differences in the lung ECM in COPD have mainly focused on some collagens and elastin, leaving an array of ECM components unexplored. We investigated the differences in the ECM landscape comparing severe-early onset (SEO)-COPD and moderate COPD to control lung tissue for collagen type I α chain 1 (COL1A1), collagen type VI α chain 1 (COL6A1); collagen type VI α chain 2 (COL6A2), collagen type XIV α chain 1 (COL14A1), fibulin 2 and 5 (FBLN2 and FBLN5), latent transforming growth factor β binding protein 4 (LTBP4), lumican (LUM), versican (VCAN), decorin (DCN), and elastin (ELN) using image analysis and statistical modeling. Percentage area and/or mean intensity of expression of LUM in the parenchyma, and COL1A1, FBLN2, LTBP4, DCN, and VCAN in the airway walls, was proportionally lower in COPD compared to controls. Lowered levels of most ECM proteins were associated with decreasing forced expiratory volume in 1 s (FEV1) measurements, indicating a relationship with disease severity. Furthermore, we identified six unique ECM signatures where LUM and COL6A1 in parenchyma and COL1A1, FBLN5, DCN, and VCAN in airway walls appear essential in reflecting the presence and severity of COPD. These signatures emphasize the need to examine groups of proteins to represent an overall difference in the ECM landscape in COPD that are more likely to be related to functional effects than individual proteins. Our study revealed differences in the lung ECM landscape between control and COPD and between SEO and moderate COPD signifying distinct pathological processes in the different subgroups.NEW & NOTEWORTHY Our study identified chronic obstructive pulmonary disease (COPD)-associated differences in the lung extracellular matrix (ECM) composition. We highlight the compartmental differences in the ECM landscape in different subtypes of COPD. The most prominent differences were observed for severe-early onset COPD. Moreover, we identified unique ECM signatures that describe airway walls and parenchyma providing insight into the intertwined nature and complexity of ECM changes in COPD that together drive ECM remodeling and may contribute to disease pathogenesis.