Risk factors and early origins of chronic obstructive pulmonary disease

Nasal Polyps in Children: The Early Origins of a Challenging Adulthood Condition

Nasal polyps (NPs) are benign inflammatory masses causing chronic nasal obstruction, usually associated with underlying chronic rhinosinusitis (CRS), which are rarely reported in childhood. The interest in NPs has recently increased due to new therapeutic options, namely biological agents, such as dupilumab, and an update of the European position paper on this topic was released in 2020, providing a detailed classification for these lesions and also discussing diagnostic and therapeutic approaches also in children. In childhood, NPs usually represent red flags for systemic diseases, such as cystic fibrosis and immunodeficiencies. This review outlines the recent data on NPs in childhood, focusing on predisposing factors for CRS as well as on the potential endotypes in this particular age group, for which further studies are required in order to better clarify their pathogenesis and to identify molecular biomarkers that could help achieve more personalized treatments.

Lung growth and pulmonary function after prematurity and bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) still carries a heavy burden of morbidity and mortality in survivors of extreme prematurity. The disease is characterized by simplification of the alveolar structure, involving a smaller number of enlarged alveoli due to decreased septation and a dysmorphic pulmonary microvessel growth. These changes lead to persistent abnormalities mainly affecting the smaller airways, lung parenchyma, and pulmonary vasculature, which can be assessed with lung function tests and imaging techniques. Several longitudinal lung function studies have demonstrated that most preterm-born subjects with BPD embark on a low lung function trajectory, never achieving their full airway growth potential. They are consequently at higher risk of developing a chronic obstructive pulmonary disease-like phenotype later in life. Studies based on computer tomography and magnetic resonance imaging, have also shown that in these patients there is a persistence of lung abnormalities like emphysematous areas, bronchial wall thickening, interstitial opacities, and mosaic lung attenuation also in adult age. This review aims to outline the current knowledge of pulmonary and vascular growth in survivors of BPD and the evidence of their lung function and imaging up to adulthood.

Association of the Tight Junction Protein Claudin-4 with Lung Function and Exacerbations in Chronic Obstructive Pulmonary Disease

Purpose

Chronic obstructive pulmonary disease (COPD) imposes a major healthcare burden. A tight junction protein, claudin-4 (CLDN4), may play a protective role in acute lung injury, but its role in COPD is unclear. To investigate the relationship between CLDN4 and COPD, we evaluated the association of CLDN4 with the clinical parameters of COPD, including exacerbations.

Patients and Methods

We analyzed a cohort of 30 patients with COPD and 25 healthy controls and evaluated their clinical parameters, including lung function. The plasma CLDN4 level in stable and exacerbated COPD was measured.

Results

The COPD patients were all males and predominantly smokers; their initial lung function was poorer than the healthy controls. The mean CLDN4 plasma level was 0.0219 ± 0.0205 ng/mg in the control group, 0.0086 ± 0.0158 ng/mg in the stable COPD group (COPD-ST) and 0.0917 ± 0.0871 ng/mg in the exacerbated COPD (COPD-EXA) group. The plasma CLDN4 level was significantly lower in the COPD-ST than the control group, but was significantly elevated in the COPD-EXA group. The plasma CLDN4 level was inversely correlated with forced vital capacity and forced expiratory volume in 1 second in the COPD-EXA group (r=0.506, P=0.001 and r=0.527, P<0.001, respectively).

Conclusion

The plasma CLDN4 level is closely correlated with COPD exacerbations and decreased lung function. This suggests that CLDN4 has potential as a severity marker for COPD.

Childhood lung function as a determinant of menopause-dependent lung function decline

RATIONALE

The naturally occurring age-dependent decline in lung function accelerates after menopause, likely due to the change of the endocrine balance. Although increasing evidence shows suboptimal lung health in early life can increase adult  susceptibility to insults, the potential effect of poor childhood lung function on menopause-dependent lung function decline has not yet been investigated.

OBJECTIVES

To study whether menopause-dependent lung function decline, assessed as forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), is determined by childhood lung function.

METHODS

The Tasmanian Longitudinal Health Study, a cohort born in 1961, underwent spirometry at age seven.  At ages 45 and 50 serum samples, spirometry and questionnaire data were collected (N = 506). We measured follicle stimulating and luteinizing hormones to determine menopausal status using latent profile analysis. The menopause-dependent lung function decline was investigated using linear mixed models, adjusted for anthropometrics, occupational level, smoking, asthma, asthma medication and study year, for the whole study population and stratified by tertiles of childhood lung function.

MEASUREMENTS AND MAIN RESULTS

The overall menopause-dependent lung function decline was 19.3 mL/y (95%CI 2.2 to 36.3) for FVC and 9.1 mL/y (-2.8 to 21.0) for FEV1. This was most pronounced (pinteraction=0.03) among women within the lowest tertile of childhood lung function [FVC 22.2 mL/y (1.1 to 43.4); FEV1 13.9 mL/y (-1.5 to 29.4)].

CONCLUSIONS

Lung function declines especially rapidly in postmenopausal women who had poor low lung function in childhood. This provides novel insights into respiratory health during reproductive aging and emphasizes the need for holistic public health strategies covering the whole lifespan.

Accelerated immunosenescence, oxidation and inflammation lead to a higher biological age in COPD patients

Chronic obstructive pulmonary disease (COPD) is characterised by inflammatory and oxidative alterations in the lung and extrapulmonary compartments, through involvement of the immune system. Several leukocyte functions are health markers and good predictors of longevity, and high pro-inflammatory and oxidative states are related to more aged profiles. Here, we aimed to investigate the aging rate in terms of immunosenescence in COPD men with respect to healthy age-matched controls. Several neutrophil (adherence, chemotaxis, phagocytosis, superoxide anion stimulated production) and lymphocyte (adherence, chemotaxis, lymphoproliferation, natural killer activity) functions, cytokine concentrations released in response to lipopolysaccharide (tumor necrosis factor-alpha, interleukin (IL)-6, IL-8, IL-10) and redox parameters (intracellular glutathione content, basal superoxide anion level) were assessed in circulating leukocytes of men with moderate and severe stages of COPD, and compared to healthy age-matched volunteers. The biological age or aging rate in each participant was determined using the values of leukocyte functions. The results indicated impairment of immune functions in COPD patients, both in innate and adaptive immunity, and higher pro-inflammatory and oxidative states in peripheral leukocytes than controls. In general, these changes were more remarkable at the severe stage of airway obstruction. Importantly, COPD patients were found to be aging at a faster rate than age-matched healthy counterparts.

Disadvantage in early-life and persistent asthma in adolescents: a UK cohort study

OBJECTIVE

To determine how early-life risk factors explain socioeconomic inequalities in persistent asthma in adolescence.

METHODS

We did a causal mediation analysis using data from 7487 children and young people in the UK Millennium Cohort Study. Persistent asthma was defined as having a diagnosis reported at any two or more time points at 7, 11 or 14 years. The main exposure was maternal education, a measure of early-life socioeconomic circumstances (SECs), used to calculate the relative index of inequality. We assessed how blocks of perinatal (maternal health behaviours, infant characteristics and duration of breastfeeding, measured at 9 months) and environmental risk factors (family housing conditions; potential exposure to infections through childcare type and sibling number, and neighbourhood characteristics, measured at 3 years) mediated the total effect of childhood SECs on persistent asthma risk, calculating the proportion mediated and natural indirect effect (NIE) via blocks of mediators.

RESULTS

At age 14 the overall prevalence of persistent asthma was 15%. Children of mothers with lower educational qualifications were more likely to have persistent asthma, with a clear social gradient (degree plus: 12.8% vs no qualifications: 20.3%). The NIE gives the effect of SECs acting only via the mediators and shows a 31% increased odds of persistent asthma when SECs are fixed at the highest level, and mediators at the level which would naturally occur at the lowest SECs versus highest SECs (NIE OR 1.31, 95% CI 1.04 to 1.65). Overall, 58.9% (95% CI 52.9 to 63.7) of the total effect (OR 1.70, 95% CI 1.20 to 2.40) of SECs on risk of persistent asthma in adolescence was mediated by perinatal and environmental characteristics.

CONCLUSIONS

Perinatal characteristics and the home environment in early life are more important in explaining socioeconomic inequalities in persistent asthma in British adolescents than more distal environmental exposures outside the home.

Network Analysis of Demographics, Dietary Intake, and Comorbidity Interactions

The aim of this study was to elucidate the complex interrelationships among dietary intake, demographics, and the risk of comorbidities. We applied a Gaussian graphical model to calculate the dietary scores of the participants. The network structure of dietary intake, demographics, and comorbidities was estimated in a mixed graphical model. The centrality indices of the nodes (strength (S), closeness (C), and betweenness (B)) were measured to identify the central node. Multinomial logistic regression was used to examine the association between the factors and comorbidities. Among 7423 participants, the strongest pairwise interactions were found between sex and smoking (1.56), sex and employment (0.66), sex and marital status (0.58), marital status and income (0.65), and age and employment (0.58). Among the factors in the network, sex played a central role (S = 4.63, C = 0.014, B = 41), followed by age (S = 2.81, C = 0.013, B = 18), smoking (S = 2.72, C = 0.013, B = 0), and employment (S = 2.17, C = 0.014, B = 22). While the odds of hypertension and diabetes were significantly higher among females than males, an inverse association was observed between high cholesterol and moderate chronic kidney disease. Among these factors, dietary intake was not a strongly interacting factor in the network, whereas age was consistently associated with the comorbidities of hypertension, high cholesterol, diabetes, and chronic kidney disease.

Indoor Radon Exposure and COPD, Synergic Association? A Multicentric, Hospital-Based Case-Control Study in a Radon-Prone Area

BACKGROUND

COPD is a multifactorial disease which causes considerable mortality and morbidity worldwide. Previous studies assessing the possible relationship between indoor radon exposure and COPD have shown inconclusive results.

METHODS

A multicentric, hospital-based, case-control study was conducted in a Spanish radon-prone area. COPD cases were confirmed by spirometry and controls were selected due to trivial surgery or procedures not related to tobacco consumption. All participants had to have lived for at least 15 years in the same dwelling. Radon measurements were conducted individually in dwellings using alpha-track detectors. Results were obtained using multivariate logistic regression.

RESULTS

189 cases and 747 controls took part. There was no significant association between residential radon concentrations and COPD onset with a OR of 1.12 (95%CI 0.41-3.06) for individuals exposed to more than 200Bq/m³ compared to those exposed to less than 50Bq/m³. Heavy smokers seem to increase their COPD risk if exposed to higher radon concentrations vs those exposed to lower concentrations. There was a statistically significant synergy index between radon exposure and tobacco consumption, S-index 11.60 (95%CI 3.71-36.26). Indoor radon concentration was higher in never/light smokers with COPD compared to controls.

CONCLUSIONS

No association between indoor radon and COPD has been observed. However, there might be some effect modification on the COPD risk in heavy smokers when high radon exposure is present. This is supported by the additive synergy observed. Also, a possible association between indoor radon and COPD onset in never and light smokers needs to be further studied.

Prediction of COPD by the single-breath nitrogen test and various respiratory symptoms

Early identification of subjects running an increased risk of contracting COPD enables focus on individual preventive measures. The slope of the alveolar plateau of the single-breath nitrogen washout test (N₂-slope) is a sensitive measure of small-airway dysfunction. However, its role remains unexplored in predicting hospital admission or death related to COPD, i.e. incident COPD events, in relation to the presence of various respiratory symptoms.

A random population sample of 625 men, aged 50 (n=218) or 60 years (n=407), was followed for 38 years for incident COPD events. At baseline, a questionnaire on respiratory symptoms and smoking habits was collected, spirometry and the single-breath nitrogen test were performed, and the N₂-slope was determined. Proportional hazard regression (Cox regression) analysis was used for the prediction model.

The N₂-slope improved the prediction of COPD events significantly beyond that of respiratory symptoms weighted all together and other covariates (hazard ratio 1.63, 95% CI 1.20–2.22; p<0.005), a prediction applicable to subjects without (p=0.001) and with (p<0.05) airway obstruction. Dyspnoea and wheezing were the most predictive symptoms. The combination of the N₂-slope and number of respiratory symptoms notably resulted in an effective prediction of incident COPD events even in nonobstructive subjects, as evidenced by a predicted incidence of ∼70% and ∼90% for a very steep N₂-slope combined with many respiratory symptoms in subject without and with airway obstruction, respectively.

The alveolar N₂-slope should be considered in the critical need for further research on early diagnosis of COPD.

The N₂ slope of the single-breath nitrogen test predicts incident COPD events as well as or better than respiratory symptoms among subjects without and with airway obstruction. Combining N₂ slope and symptoms results in effective prediction.https://bit.ly/3dYJdu1

Prenatal exposure to arsenic and lung function in children from the New Hampshire Birth Cohort Study

Prenatal arsenic exposure is associated with an increased risk of lung cancer along with multiple non-carcinogenic outcomes, including respiratory diseases in arsenic-contaminated areas. Limited epidemiologic data exist on whether in utero arsenic exposure influences lung development and subsequent respiratory health. We investigated the association between gestational arsenic exposure and childhood lung function in the New Hampshire Birth Cohort Study. Urinary arsenic speciation including inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine was measured in maternal urine samples collected during pregnancy and spirometry was performed in offspring at a median age of 7.4 years. Forced vital capacity (FVC), forced expiratory volume in the first second of exhalation (FEV1), and forced expiratory flow between 25% and 75% of FVC (FEF25-75) standardized z-scores were assessed in linear models as dependent variables with the log2-transformed summation of urinary arsenic species (ΣAs = iAs + MMA + DMA) corrected for specific gravity as an independent variable and with adjustment for maternal smoking status, children's age, sex and height. Among the 358 children in the study, a doubling of ΣAs was associated with a -0.08 (ß) decrease in FVC z-scores (95% confidence interval (CI) from -0.14 to -0.01) and -0.10 (ß) (95% CI from -0.18 to -0.02) decrease in FEV1 z-scores. The inverse association appeared stronger among those mothers with lower secondary methylation index (urinary DMA/MMA), especially among girls. No association was observed for FEF25-75 z-scores. Our results suggest that gestation arsenic exposure at levels relevant to the general US population during the vulnerable period of lung formation may adversely affect lung function in childhood.

Survival Impact of Current-Smoking-Related COPD or COPD with Acute Exacerbation on Bladder Preservation through Concurrent Chemoradiotherapy for Muscle-Invasive Bladder Urothelial Carcinoma

PURPOSE: The survival effect of smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) on patients with muscle-invasive bladder urothelial carcinoma (MIBUC) receiving concurrent chemoradiotherapy (CCRT) for bladder preservation is unclear. METHODS: We recruited patients with MIBUC, clinical stages IIA-IVB, who had received maximal transurethral resection of bladder tumor (TURBT) followed by CCRT from the Taiwan Cancer Registry Database. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into two groups by using propensity score matching based on the preexisting COPD status (within 1 year before CCRT) to compare overall survival outcomes: Group 1 (never smokers without COPD) and Group 2 (current smokers with COPD). RESULTS: In multivariate Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality in Group 2 compared with Group 1 was 1.89 (1.12-3.18), p = 0.017. The aHRs (95% CIs) of all-cause mortality for ≥1 and ≥2 hospitalizations for COPDAE within 1 year before CCRT for bladder preservation were 3.26 (1.95-5.46) and 6.33 (3.55-11.281) compared with non-COPDAE patients with MIBUC undergoing CCRT for bladder preservation. CONCLUSIONS: Among patients with MIBUC undergoing TURBT followed by CCRT for bladder preservation, current smokers with smoking-related COPD had worse survival outcomes than did nonsmokers without COPD. CONDENSED ABSTRACT: This was the first study to estimate the survival impact of smoking-related chronic obstructive pulmonary disease (COPD) on patients with muscle-invasive bladder urothelial carcinoma (MIBUC) receiving maximal transurethral resection of bladder tumor (TURBT) followed by concurrent chemoradiotherapy (CCRT) for bladder preservation. Smoking-related COPD was a significant independent risk factor for all-cause mortality in patients with clinical stages IIA-IVB receiving TURBT followed by CCRT. Hospitalization frequency for COPD with at least one acute exacerbation within 1 year before CCRT was highly associated with high mortality for patients with MIBUC receiving CCRT for bladder preservation. Not only all-cause death but also bladder cancer death and COPD death were significantly higher in the current-smoking COPD group than in the never-smoking non-COPD group.

Activation of immune cell proteasomes in peripheral blood of smokers and COPD patients - implications for therapy

Immune cells contain a specialised type of proteasome, i.e. the immunoproteasome, which is required for intracellular protein degradation. Immunoproteasomes are key regulators of immune cell differentiation, inflammatory activation and autoimmunity. Immunoproteasome function in peripheral immune cells might be altered by smoking and in COPD thereby affecting immune cell responses.We here analysed the expression and activity of proteasome complexes in peripheral blood mononuclear cells (PBMC) isolated from healthy male young smokers as well as from patients with severe COPD and compared them to matching controls. Proteasome expression was upregulated in COPD patients as assessed by RT-qPCR and mass spectrometry-based proteomics analysis. Proteasome activity was quantified using activity-based probes and native gel analysis. We observed distinct activation of immunoproteasomes in the peripheral blood cells of young male smokers and severely ill COPD patients. Native gel analysis and linear regression modeling confirmed robust activation and elevated assembly of 20S proteasomes, which correlated significantly with reduced lung function parameters in COPD patients. The immunoproteasome was distinctly activated in COPD patients upon inflammatory cytokine stimulation of PBMCs in vitro Inhibition of the immunoproteasome reduced proinflammatory cytokine expression in COPD-derived blood immune cells.Given the crucial role of chronic inflammatory signalling and the emerging involvement of autoimmune responses in COPD, therapeutic targeting of the immunoproteasome might represent a novel therapeutic concept for COPD.

Relationships between Long-Term Ozone Exposure and Allergic Rhinitis and Bronchitic Symptoms in Chinese Children

Numerous studies have demonstrated that exposure to ambient ozone (O₃) could have adverse effects on children's respiratory health. However, previous studies mainly focused on asthma and wheezing. Evidence for allergic rhinitis and bronchitic symptoms (e.g., persistent cough and phlegm) associated with O₃ is limited, and results from existing studies are inconsistent. This study included a total of 59,754 children from the seven northeastern cities study (SNEC), who were aged 2 to 17 years and from 94 kindergarten, elementary and middle schools. Information on doctor-diagnosed allergic rhinitis (AR), persistent cough, and persistent phlegm was collected during 2012-2013 using a standardized questionnaire developed by the American Thoracic Society (ATS). Information for potential confounders was also collected via questionnaire. Individuals' exposure to ambient ozone (O₃) during the four years before the investigation was estimated using a satellite-based random forest model. A higher level of O₃ was significantly associated with increased risk of AR and bronchitic symptoms. After controlling for potential confounders, the OR (95% CI) were 1.13 (1.07-1.18), 1.10 (1.06-1.16), and 1.12 (1.05-1.20) for AR, persistent cough, and persistent phlegm, respectively, associated with each interquartile range (IQR) rise in O₃ concentration. Interaction analyses showed stronger adverse effects of O₃ on AR in children aged 7-17 years than those aged 2-6 years, while the adverse association of O₃ with cough was more prominent in females and children aged 7-12 years than in males and children aged 2-6 and 13-17 years. This study showed that long-term exposure to ambient O₃ was significantly associated with higher risk of AR and bronchitic symptoms in children, and the association varies across age and gender. Our findings contribute additional evidence for the importance of controlling O₃ pollution and protecting children from O₃ exposure.

Neutrophilic inflammation during lung development disrupts elastin assembly and predisposes adult mice to COPD

Emerging evidence indicates that early life events can increase the risk for developing chronic obstructive pulmonary disease (COPD). Using an inducible transgenic mouse model for NF-κB activation in the airway epithelium, we found that a brief period of inflammation during the saccular stage (P3-P5) but not alveolar stage (P10-P12) of lung development disrupted elastic fiber assembly, resulting in permanent reduction in lung function and development of a COPD-like lung phenotype that progressed through 24 months of age. Neutrophil depletion prevented disruption of elastic fiber assembly and restored normal lung development. Mechanistic studies uncovered a role for neutrophil elastase (NE) in downregulating expression of critical elastic fiber assembly components, particularly fibulin-5 and elastin. Further, purified human NE and NE-containing exosomes from tracheal aspirates of premature infants with lung inflammation downregulated elastin and fibulin-5 expression by saccular-stage mouse lung fibroblasts. Together, our studies define a critical developmental window for assembling the elastin scaffold in the distal lung, which is required to support lung structure and function throughout the lifespan. Although neutrophils play a well-recognized role in COPD development in adults, neutrophilic inflammation may also contribute to early-life predisposition to COPD.

Hypertensive disorders in pregnancy and risk of asthma in offspring: a systematic review and meta-analysis

OBJECTIVES

The association between hypertensive disorders in pregnancy (HDP) and an increased risk of asthma in offspring remains controversial. No systematic review of this topic has been performed. The aim of this systematic review was to summarise the available evidence regarding the association between HDP and the risk of asthma in offspring.

DESIGN

Systematic review and meta-analysis.

METHODS

On the basis of a prepared protocol, a systematic search of PubMed, EMBASE, the Cochrane Library and Web of Science was performed using a detailed search strategy from the database inception to 17 January 2020. Cohort, case-control and cross-sectional studies published in English reporting the diagnoses of maternal HDP and asthma in offspring were included. The Meta-analysis of Observational Studies in Epidemiology guidelines were followed throughout the study. The estimated pooled ORs of HDP and asthma in offspring were calculated from the studies, and the meta-analysis was performed using random-effects models.

RESULTS

Ten cohort studies involving a total of 6 270 430 participants were included. According to the Newcastle-Ottawa Scale, the overall methodological quality was good since 8 studies were of high quality and 2 studies were of moderate quality. After controlling for potential confounders, HDP was associated with a possible increased risk of asthma in offspring, with a pooled adjusted OR (aOR) of 1.19 (95% CI 1.12 to 1.26). The subgroup analyses according to HDP subgroups, sibling design, study quality, study location, offspring ages, singleton status, exposure assessment, outcome assessment and adjusted factors showed similar results.

CONCLUSIONS

Exposure to HDP may be associated with an increased risk of asthma in offspring. Further research is needed to verify the results and determine whether the observed relationship is causal.

PROSPERO REGISTRATION NUMBER

CRD42020148250.

Chorioamnionitis induces changes in ovine pulmonary endogenous epithelial stem/progenitor cells in utero

BACKGROUND

Chorioamnionitis, an intrauterine infection of the placenta and fetal membranes, is a common risk factor for adverse pulmonary outcomes in premature infants including BPD, which is characterized by an arrest in alveolar development. As endogenous epithelial stem/progenitor cells are crucial for organogenesis and tissue repair, we examined whether intrauterine inflammation negatively affects these essential progenitor pools.

METHODS

In an ovine chorioamnionitis model, fetuses were intra-amniotically exposed to LPS, 2d or 7d (acute inflammation) before preterm delivery at 125d of gestation, or to intra-amniotic Ureaplasma parvum for 42d (chronic inflammation). Lung function, pulmonary endogenous epithelial stem/progenitor pools, and downstream functional markers were studied.

RESULTS

Lung function was improved in the 7d LPS and 42d Ureaplasma groups. However, intrauterine inflammation caused a loss of P63+ basal cells in proximal airways and reduced SOX-9 expression and TTF-1+ Club cells in distal airways. Attenuated type-2 cell numbers were associated with lower proliferation and reduced type-1 cell marker Aqp5 expression, indicative for impaired progenitor function. Chronic Ureaplasma infection only affected distal airways, whereas acute inflammation affected stem/progenitor populations throughout the lungs.

CONCLUSIONS

Acute and chronic prenatal inflammation improve lung function at the expense of stem/progenitor alterations that potentially disrupt normal lung development, thereby predisposing to adverse postnatal outcomes.

IMPACT

In this study, prenatal inflammation improved lung function at the expense of stem/progenitor alterations that potentially disrupt normal lung development, thereby predisposing to adverse postnatal outcomes. Importantly, we demonstrate that these essential alterations can already be initiated before birth. So far, stem/progenitor dysfunction has only been shown postnatally. This study indicates that clinical protocols to target the consequences of perinatal inflammatory stress for the immature lungs should be initiated as early as possible and ideally in utero. Within this context, our data suggest that interventions, which promote function or repair of endogenous stem cells in the lungs, hold great promise.

Parenchymal destruction in asthma: Fixed airflow obstruction and lung function trajectory

BACKGROUND

Fixed airflow obstruction (FAO) in asthma, particularly in nonsmokers, is generally believed to be caused by airway remodeling. However, parenchymal destruction may also contribute to FAO and longitudinal decline in forced expiratory volume in 1 second (FEV₁).

OBJECTIVES

To evaluate parenchymal destruction, we used emphysema indices, exponent D, and low-attenuation area percentage (LAA%) on computed tomography (CT), and test whether the parenchymal destruction and airway disease are independently associated with FAO and FEV₁ decline in both smoking and nonsmoking asthma.

METHODS

Exponent D, LAA%, wall area percentage at segmental airways, and airway fractal dimension (AFD) in those with asthma were measured on inspiratory CT and compared to those in patients with chronic obstructive pulmonary disease (COPD).

RESULTS

Exponent D was lower and LAA% was higher in COPD (n = 42) and asthma with FAO (n = 101) than in asthma without FAO (n = 88). The decreased exponent D and increased LAA% were associated with FAO regardless of smoking status or asthma severity. In multivariable analysis, decreased exponent D and increased LAA% were associated with an increased odds ratio of FAO and decreased FEV₁, irrespective of wall area percentage and airway fractal dimension. Moreover, decreased exponent D affected the longitudinal decline in FEV₁ in those with severe asthma, independent of smoking status.

CONCLUSIONS

Patients with asthma with FAO showed parenchymal destruction regardless of smoking status and asthma severity. Parenchymal destruction was associated with an accelerated FEV₁ decline, suggesting the involvements of both airway and parenchyma in the pathophysiology of a subgroup of asthma.

Prevalence and characteristics of chronic obstructive pulmonary disease in China with a diagnostic criterion of FEV1/FVC less than the lower limit of normal-a reanalysis of Chinese epidemiological survey of COPD (CESCOPD) study

Background

To reappraise the prevalence and characteristics of chronic obstructive pulmonary disease (COPD) in China with a criterion of FEV₁/FVC < the lower limit of normal (LLN).

Methods

We assessed the incidence and characteristics of airflow limitation using data from the Chinese Epidemiological Survey of COPD study-a multicenter, randomized trial, with an age-dependent LLN reference equation [established by the Guangzhou Institute of Respiratory Health (GIRH)]. Questionnaire and spirometry data were collected for all eligible subjects. COPD prevalence, risk factors, severity distribution, as well as comparisons of characteristics between the LLN and 0.7 were analyzed.

Results

COPD prevalence was 9.0% among participants aged 40-80 years in China with the criterion of LLN. Greater prevalence was observed in female sex, rural areas and never smokers than with the GOLD 0.7 fixed ratio. Age distribution showed a higher incidence of COPD in people under 60 years but lower in participants over 60 years of age. With the LLN FEV₁ reference equation, patients in stage I were decreased (15.8% vs. 24.6%, P<0.001), while the proportion of patients in stage III and IV were increased when compared with the China 2002 revised equation (27.7% vs. 21.1%, for stage III, P<0.001; 8.7% vs. 5.6% for stage IV, P=0.001). Only 30.8% of patients with COPD had ever been "diagnosed" with COPD and 60.6% of the patients had respiratory symptoms, both lower than that under the GOLD 0.7 fixed-ratio criterion (35.5%, P=0.004; 64.8% for symptoms, P=0.014).

Conclusions

With the GIRH-LLN criterion, COPD prevalence was slightly higher, and a large number of women, rural patients and nonsmokers with young age and little symptoms were diagnosed when compared with GOLD 0.7 fixed ratio. These subjects may, therefore, deserve further attention and may warrant regular follow-up.

Trial Registration

Registration number: ChiCTR-ECS-13004110.

Respiratory Effects of Exposure to Aerosol From the Candidate Modified-Risk Tobacco Product THS 2.2 in an 18-Month Systems Toxicology Study With A/J Mice

Smoking cessation is the most effective measure for reducing the risk of smoking-related diseases. However, switching to less harmful products (modified-risk tobacco products [MRTP]) can be an alternative to help reduce the risk for adult smokers who would otherwise continue to smoke. In an 18-month chronic carcinogenicity/toxicity study in A/J mice (OECD Test Guideline 453), we assessed the aerosol of Tobacco Heating System 2.2 (THS 2.2), a candidate MRTP based on the heat-not-burn principle, compared with 3R4F cigarette smoke (CS). To capture toxicity- and disease-relevant mechanisms, we complemented standard toxicology endpoints with in-depth systems toxicology analyses. In this part of our publication series, we report on integrative assessment of the apical and molecular exposure effects on the respiratory tract (nose, larynx, and lungs). Across the respiratory tract, we found changes in inflammatory response following 3R4F CS exposure (eg, antimicrobial peptide response in the nose), with both shared and distinct oxidative and xenobiotic responses. Compared with 3R4F CS, THS 2.2 aerosol exerted far fewer effects on respiratory tract histology, including adaptive tissue changes in nasal and laryngeal epithelium and inflammation and emphysematous changes in the lungs. Integrative analysis of molecular changes confirmed the substantially lower impact of THS 2.2 aerosol than 3R4F CS on toxicologically and disease-relevant molecular processes such as inflammation, oxidative stress responses, and xenobiotic metabolism. In summary, this work exemplifies how apical and molecular endpoints can be combined effectively for toxicology assessment and further supports findings on the reduced respiratory health risks of THS 2.2 aerosol.

Associations between respiratory and vascular function in early childhood

BACKGROUND AND OBJECTIVE

The link between respiratory and vascular health is well documented in adult populations. Impaired lung function is consistently associated with thicker arteries and higher incidence of cardiovascular disease. However, there are limited data on this relationship in young children and the studies that exist have focussed on populations at high risk of cardiorespiratory morbidity. We determined if an association exists between respiratory and cardiovascular function in young children and, if so, whether it is confounded by known cardiorespiratory risk factors.

METHODS

Respiratory and vascular data from a prospective cohort study established to evaluate the health implications 3 years after coal mine fire smoke exposure in children aged 3-5 years were used. Respiratory function was measured using the forced oscillation technique and included resistance at 5 Hz (R₅ ), reactance at 5 Hz (X₅ ) and area under the reactance curve (AX). Vascular health was measured by carotid intima-media thickness (ultrasound) and pulse wave velocity (arterial tonometry). Regression analyses were used to examine the relationship between the respiratory Z-scores and cardiovascular measures. Subsequent analyses were adjusted for potential confounding by maternal smoking during pregnancy, maternal education and exposure to fine particulate matter <2.5 μm in aerodynamic diameter (PM_2.5 ).

RESULTS

Peripheral lung function (X₅ and AX), but not respiratory system resistance (R₅ ), was associated with vascular function. Adjustment for maternal smoking, maternal education and early life exposure to PM_2.5 had minimal effect on these associations.

CONCLUSION

These observations suggest that peripheral lung stiffness is associated with vascular stiffness and that this relationship is established early in life.

Challenges in the Implementation of Chronic Obstructive Pulmonary Disease Guidelines in Low- and Middle-Income Countries: An Official American Thoracic Society Workshop Report

There is a substantial burden of chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), in low- and middle-income countries (LMICs). LMICs have particular challenges in delivering cost-effective prevention, diagnosis, and management of COPD. Optimal care can be supported by effective implementation of guidelines. This American Thoracic Society workshop considered challenges to implementation of COPD guidelines in LMICs. We make 10 specific recommendations: 1) relevant organizations should provide LMIC-specific COPD management guidance; 2) patient and professional organizations must persuade policy-makers of the importance of lung function testing programs in LMICs; 3) healthcare education and training should emphasize the early-life origins of COPD; 4) urgent action is required by governments to reduce airborne exposures, including exposures to tobacco smoke and indoor and outdoor air pollution; 5) guidance for COPD in LMICs should explicitly link across Essential Medicine Lists and the World Health Organization package of essential noncommunicable disease interventions for primary health care in low-resource settings and should consider availability, affordability, sustainability, and cost-effective use of medicines; 6) the pharmaceutical industry should work to make effective COPD and tobacco-dependence medicines globally accessible and affordable; 7) implementation of locally adapted, cost-effective pulmonary rehabilitation programs should be an international priority; 8) the World Health Organization Global Action Plan for the Prevention and Control of Noncommunicable Diseases should specify how improvements in respiratory health will be achieved; 9) research funders should increase the proportion of funding allocated to COPD in LMICs; and 10) the respiratory community should leverage the skills and enthusiasm of earlier-career clinicians and researchers to improve global respiratory health.

Importance of Early COPD in Young Adults for Development of Clinical COPD: Findings from the Copenhagen General Population Study

Rationale: Individuals who will develop chronic obstructive pulmonary disease (COPD) could be identified at an early age before clinical manifestations appear. Objectives: We investigated risk of clinical COPD 10 years later in young adults from the general population with and without early COPD with a focus on smoking exposure. Methods: We included 14,870 individuals aged 20-100 years from the Copenhagen General Population Study with spirometry 10 years apart. Early COPD was defined as baseline FEV₁/FVC less than the lower limit of normal in individuals aged <50 years. Outcomes included clinical COPD at final examination 10 years later (chronic respiratory symptoms with FEV₁/FVC <0.70 and FEV₁ <80% predicted) and acute exacerbation hospitalizations during follow-up. Measurements and Main Results: Among 5,497 individuals aged <50 years at baseline with FEV₁/FVC ≥0.70, 104 (3%) developed clinical COPD 10 years later; 4% of smokers with ≥10 pack-years had early COPD; 3% of smokers with <10 pack-years had early COPD; and 2% of never-smokers had early COPD. Among smokers with ≥10 pack-years, 24% developed clinical COPD in those with early COPD versus 4% in those without early COPD. Corresponding numbers were 10% and 1% in smokers with <10 pack-years and 3% and <1% in never-smokers, respectively. Among individuals with early COPD, odds ratios for clinical COPD 10 years later were 7.77 (95% confidence interval [CI], 4.10-14.7) in smokers with ≥10 pack-years and 8.56 (95% CI, 4.92-14.9) in all smokers, whereas hazard ratios for acute exacerbation hospitalizations were 4.16 (95% CI, 1.66-10.5) and 4.33 (95% CI, 1.89-9.93), respectively. Results were validated in the Copenhagen City Heart Study. Conclusions: Depending on amount of smoking exposure, <24% of young adults in the general population with early COPD develop clinical COPD 10 years later. A smoking exposure threshold for early COPD should be reconsidered, as younger individuals are less represented in those with high smoking exposure.

The "Slow Horse Racing Effect" on Lung Function in Adult Life in Chronic Obstructive Pulmonary Disease Associated to Biomass Exposure

Although different trajectories in lung function decline have been identified in patients with COPD associated to tobacco exposure (TE-COPD), genetic, environmental, and infectious factors affecting lung function throughout life have not been fully elucidated in patients with COPD associated to biomass (BE-COPD). In this review, we present current epidemiological findings and notable advances in the natural history of lung decline in BE-COPD, as well as conditions modeling the FEV₁ trajectory, such as health insults, during the first years of childhood. Evidence shows that women exposed to biomass smoke reach adult life with a lower FEV₁ than expected. However, in contrast to the “horse racing effect” predicting an excessive lung-function decline in forthcoming years, as observed in smokers, this decline is slower in non-smokers, and no rapid decliners are observed. Accordingly, BE-COPD might be considered another phenotype of COPD based on assessments of lung function decline. Likewise, other functional and clinical aspects described in this review suggest that this condition might be similar to TE-COPD. More research is needed to fully characterize this subgroup of variants of COPD.

Examining the possible causal relationship between lung function, COPD and Alzheimer's disease: a Mendelian randomisation study

Rationale

Large retrospective case-control studies have reported an association between chronic obstructive pulmonary disease (COPD), reduced lung function and an increased risk of Alzheimer’s disease. However, it remains unclear if these diseases are causally linked, or due to shared risk factors. Conventional observational epidemiology suffers from unmeasured confounding and reverse causation. Additional analyses addressing causality are required.

Objectives

To examine a causal relationship between COPD, lung function and Alzheimer’s disease.

Methods

Using two-sample Mendelian randomisation, we used single nucleotide polymorphisms (SNPs) identified in a genome wide association study (GWAS) for lung function as instrumental variables (exposure). Additionally, we used SNPs discovered in a GWAS for COPD in those with moderate to very severe obstruction. The effect of these SNPs on Alzheimer’s disease (outcome) was taken from a GWAS based on a sample of 24 807 patients and 55 058 controls.

Results

We found minimal evidence for an effect of either lung function (OR: 1.02 per SD; 95% CI 0.91 to 1.13; p value 0.68) or liability for COPD on Alzheimer’s disease (OR: 0.97 per SD; 95% CI 0.92 to 1.03; p value 0.40).

Conclusion

Neither reduced lung function nor liability COPD are likely to be causally associated with an increased risk of Alzheimer’s, any observed association is likely due to unmeasured confounding. Scientific attention and health prevention policy may be better focused on overlapping risk factors, rather than attempts to reduce risk of Alzheimer’s disease by targeting impaired lung function or COPD directly.

Prevalence and quality of care among patients using medication targeting obstructive lung disease: a cross-sectional study in the five regions of Greenland

The aim of this study was to estimate the age- and gender-specific prevalence and quality of care among patients using medication targeting obstructive lung disease in the five regions of Greenland. The study was designed as a cross-sectional study. Data on patients using medication targeting obstructive lung disease was obtained from the electronically medical record used in Greenland. The prevalence was calculated using the population of Greenland as background population. The quality of care was determined using indicators proposed by international literature and the Steno Diabetes Center Greenland guidelines. The total prevalence of patients using medication targeting obstructive lung disease was 7.5%. The prevalence was significantly higher among women compared to men and differed significantly between the five regions. Smoking status, blood pressure and spirometry were registered within one/two years for 29.8%/43.2%, 29.2%/41.1% and 15.9%/26.0% of the patients, respectively. Regional differences were observed for all indicators.

The use of medication targeting obstructive lung disease is common in Greenland. Yet, the quality of care was low and interventions improving the quality of care is recommended.

Supernormal lung function and risk of COPD: A contemporary population-based cohort study

BACKGROUND

Investigation of the natural history of chronic obstructive pulmonary disease (COPD) has led to the recognition that individuals with higher than normal lung function may have lower risk of developing COPD. We tested the hypothesis that individuals with supernormal lung function have lower risk of COPD.

METHODS

We followed 108,246 adults from the Copenhagen General Population Study recruited between 2003 and 2015 for clinical COPD outcomes until 2018. A subset of 16,892 attended another examination approximately 10 years later, allowing to investigate lung function decline and COPD development (forced expiratory volume in 1 se (FEV₁)/forced vital capacity (FVC)<0·70 and FEV₁<80% predicted with chronic respiratory symptom). Supernormal lung function was defined as FEV₁>upper limit of normal (ULN).

FINDINGS

At baseline, 3944(4%) had supernormal lung function, 91,938(85%) normal lung function, and 12,364(11%) had below normal lung function. Individuals with baseline supernormal versus normal lung function had higher FEV₁ decline but did not differ in FEV₁/FVC decline. None had COPD at 10 years in those with supernormal lung function, while 3% had in those with normal lung function. Early-life risk factors associated with COPD development and smoking exposure in different stages of life were less common in individuals with supernormal lung function. Compared to individuals with normal lung function, multivariable adjusted hazard ratios in those with supernormal lung function were 0·19(95% confidence interval:0·08-0·46) for acute obstructive lung disease hospitalisations, 0·56(0·45-0·69) for pneumonia hospitalisations, and 0·81(0·72-0·91) for all-cause mortality.

INTERPRETATION

Supernormal lung function is associated with lower risk of developing COPD.

FUNDING

Herlev and Gentofte Hospital and Lundbeck Foundation.

Cannabis Use, Pulmonary Function, and Lung Cancer Susceptibility: A Mendelian Randomization Study

INTRODUCTION

Because of widespread use, understanding the pulmonary effects of cannabis use is important; but its role independent from tobacco smoking is yet to be elucidated. We used Mendelian randomization (MR) to assess the effect of genetic liability to lifetime cannabis use and cannabis use disorder on pulmonary function and lung cancer.

METHODS

We used four single nucleotide polymorphisms associated with lifetime cannabis use (p value <5 × 10-8) from a genome-wide association study (GWAS) of 184,765 individuals of European descent from the International Cannabis Consortium, 23andme, and U.K. Biobank as instrumental variables. Seven single nucleotide polymorphisms (p value <5 × 10-8) were selected as instruments for cannabis use disorder from a GWAS meta-analysis of 17,068 European ancestry cases and 357,219 controls of European descent from Psychiatric Genomics Consortium Substance Use Disorders working group, Lundbeck Foundation Initiative for Integrative PsychiatricResearch, and deCode. To assess lung function, GWAS included 79,055 study participants of the SpiroMeta Consortium, and for lung cancer GWAS from the International Lung Cancer Consortium contained 29,266 cases and 56,450 controls.

RESULTS

MR revealed that genetic liability to lifetime cannabis use was associated with increased risk of squamous cell carcinoma (OR = 1.22, 95%, confidence interval = 1.07-1.39, p value = 0.003, q value = 0.025). Pleiotropy-robust methods and positive and negative control analyses did not indicate bias in the primary analysis.

CONCLUSIONS

The findings of this MR analysis suggest evidence for a potential causal association between genetic liability for cannabis use and the risk of squamous cell carcinoma. Triangulating MR and observational studies and addressing orthogonal sources of bias are necessary to confirm this finding.

Sex-specific longitudinal association of DNA methylation with lung function

Investigating whether DNA methylation (DNA-M) at an earlier age is associated with lung function at a later age and whether this relationship differs by sex could enable prediction of future lung function deficit. A training/testing-based technique was used to screen 402 714 cytosine-phosphate-guanine dinucleotide sites (CpGs) to assess the longitudinal association of blood-based DNA-M at ages 10 and 18 years with lung function at 18 and 26 years, respectively, in the Isle of Wight birth cohort (IOWBC). Multivariable linear mixed models were applied to the CpGs that passed screening. To detect differentially methylated regions (DMRs), DMR enrichment analysis was conducted. Findings were further examined in the Avon Longitudinal Study of Parents and Children (ALSPAC). Biological relevance of the identified CpGs was assessed using gene expression data. DNA-M at eight CpGs (five CpGs with forced expiratory volume in 1 s (FEV1) and three CpGs with FEV1/forced vital capacity (FVC)) at an earlier age was associated with lung function at a later age regardless of sex, while at 13 CpGs (five CpGs with FVC, three with FEV1 and five with FEV1/FVC), the associations were sex-specific (p FDR <0.05) in IOWBC, with consistent directions of association in ALSPAC (IOWBC-ALSPAC consistent CpGs). cg16582803 (WNT10A) and cg14083603 (ZGPAT) were replicated in ALSPAC for main and sex-specific effects, respectively. Among IOWBC-ALSPAC consistent CpGs, DNA-M at cg01376079 (SSH3) and cg07557690 (TGFBR3) was associated with gene expression both longitudinally and cross-sectionally. In total, 57 and 170 DMRs were linked to lung function longitudinally in males and females, respectively. CpGs showing longitudinal associations with lung function have the potential to serve as candidate markers in future studies on lung function deficit prediction.

Persistent airflow obstruction in inner-city children with asthma

Background: Airway remodeling has been shown to be persistent in patients with asthma despite treatment with controller medications. Patients with early airflow obstruction may continue to experience poor lung function despite treatment. Objectives: To determine whether early airflow obstruction in inner-city children with asthma persists despite guideline-based asthma care. Methods: In a retrospective study that used a cohort of inner-city children with asthma treated by using an asthma-specific disease management system, the patients were stratified into "low" or "high" lung function groups at the time of the initial visit (high, forced expiratory volume in the first second of expiration [FEV₁] % predicted and FEV₁/forced vital capacity [FVC] ≥ 80%; and low, FEV₁% predicted and FEV₁/FVC < 80%). These patients then received National Heart, Lung, and Blood Institute guideline-based asthma treatment at regular follow-up intervals with spirometry performed at these visits as part of regular care. FEV₁% predicted and FEV₁/FVC were followed up for up to 10 years for both the high and low cohorts. Results: Over 10 years, the patients initially in the "high" group maintained FEV₁% predicted and FEV₁/FVC at values similar to the initial visit (94 to 96% and 87 to 89%, respectively), whereas those in the low group had only slight increases of FEV₁% predicted and FEV₁/FVC over the same time (77 to 82% and 78 to 82%, respectively). Low FEV₁% predicted and FEV₁/FVC at the time of the first visit was significantly associated with an increased risk of low values of these lung functions over the next 3-5 years despite treatment. African American ethnicity and male gender were also associated with lower lung function over time. Conclusion: Early airflow obstruction in inner city children asthma is associated with poor lung function in later life despite guideline-based asthma care. Current asthma therapy may not affect pathways and leads to airway remodeling in children with asthma.

Chronic Obstructive Pulmonary Disease: Epidemiology, Biomarkers, and Paving the Way to Lung Cancer

Chronic obstructive pulmonary disease (COPD), the frequently fatal pathology of the respiratory tract, accounts for half a billion cases globally. COPD manifests via chronic inflammatory response to irritants, frequently to tobacco smoke. The progression of COPD from early onset to advanced disease leads to the loss of the alveolar wall, pulmonary hypertension, and fibrosis of the respiratory epithelium. Here, we focus on the epidemiology, progression, and biomarkers of COPD with a particular connection to lung cancer. Dissecting the cellular and molecular players in the progression of the disease, we aim to shed light on the role of smoking, which is responsible for the disease, or at least for the more severe symptoms and worse patient outcomes. We summarize the inflammatory conditions, as well as the role of EMT and fibroblasts in establishing a cancer-prone microenvironment, i.e., the soil for ‘COPD-derived’ lung cancer. We highlight that the major health problem of COPD can be alleviated via smoking cessation, early diagnosis, and abandonment of the usage of biomass fuels on a global basis.

lncRNA TUG1 regulates human pulmonary microvascular endothelial cell apoptosis via sponging of the miR-9a-5p/BCL2L11 axis in chronic obstructive pulmonary disease

The aim of the present study was to investigate the function of long non-coding RNA taurine-upregulated gene 1 (lncRNA TUG1) in chronic obstructive pulmonary disease and further assess the underlying molecular mechanisms. Flow cytometry analysis was performed to detect cell apoptosis of human pulmonary microvascular endothelial cells (HPMECs) treated with 1% cigarette smoke extract (CSE). The activity of caspase-3 was measured using a Caspase-3 Activity assay kit and the protein expression of cleaved caspase-3, caspase-3 and Bcl-2 like 11 (BCL2L11) were measured using western blotting. Reverse transcription-quantitative PCR (RT-qPCR) was performed to measure the expression of TUG1 mRNA levels in the treated cells. The association between TUG1, the miR-9a-5p/BCL2L11 axis and with miR-9a-5p were predicted and verified using a dual luciferase reporter assay system. The mRNA expression of miR-9a-5p and BCL2L11, and the transfection efficiency were measured by RT-qPCR. The results showed that CSE induced cell apoptosis and increased lncRNA TUG1 expression in HPMECs. CSE significantly reduced the expression of miR-9a-5p in HPMECs compared with the control group. TUG1-short hairpin RNA relieved cell apoptosis induced by CSE by upregulating miR-9a-5p in HPMECs. The present study predicted and verified that BCL2L11 is a direct target of miR-9a-5p. The mRNA expression of BCL2L11 was increased in HPMECs following CSE treatment compared with the control group. miR-9a-5p mimic and BCL2L11-plasmid markedly increased the expression of miR-9a-5p and BCL2L11, respectively. miR-9a-5p mimic reversed the increase in cell apoptosis induced by CSE by inhibiting BCL2L11 expression in HPMECs. To conclude, the present study demonstrated that lncRNA TUG1 exerted roles in cell apoptosis induced by CSE through modulating the miR-9a-5p/BCL2L11 axis.

Associations of genetic risk and smoking with incident chronic obstructive pulmonary disease

BACKGROUND

Genetic and smoking contribute to chronic obstructive pulmonary disease (COPD), but whether a combined polygenic risk score (PRS) is associated with incident COPD and whether it has a synergistic effect on the smoking remains unclear. We aimed to investigate the association of PRS with COPD and explore whether smoking behaviors could modify such association.

METHODS

Multivariable Cox proportional models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association of the PRS and smoking with COPD.

RESULTS

The study included 439 255 participants (mean age 56.5; 53.9% female), with a median follow-up of 9.0 years. The PRS_lasso containing 2.5 million variants showed better discrimination and a stronger association for incident COPD than the PRS₂₇₉ containing 279 genome-wide significance variants. Compared with the low genetic risk, the HRs of the medium and high genetic risk were 1.39 (95% CI, 1.31-1.48) and 2.40 (95% CI, 2.24-2.56), respectively. The HR of high genetic risk and current smoking was 11.62 (95% CI, 10.31-13.10) times of low genetic risk and never smoking. There were significant interactions between the PRS_lasso and smoking status for incident COPD (p for interaction<0.001). From low genetic risk to high genetic risk, the HRs of current smoking increased from 4.32 (95% CI, 3.69-5.06) to 6.89 (95% CI, 6.21-7.64), and the population-attributable risks of smoking increased from 42.7% to 61.1%.

CONCLUSION

PRS constructed from millions of variants below genome-wide significance showed significant associations with incident COPD. Participants with a high genetic risk may be more susceptible to developing COPD when exposed to smoking.

Respiratory Disease Occupational Biomonitoring Collaborative Project (ROBoCoP): A longitudinal pilot study and implementation research in the Parisian transport company

The ROBoCoP project is launched within the EU COST Action CA16113 “CliniMARK” aiming to increase the number of clinically validated biomarkers and focused on chronic obstructive pulmonary disease (COPD) biomarker development and validation. ROBoCoP encompasses two consecutive studies consisting of a pilot study followed by a field study. The pilot study is a longitudinal exposure assessment and biomarker study aiming at: 1-understanding the suitability of the candidate biomarkers in surveying populations at risk such as workers exposed to COPD causing agents; 2-determining the best sampling plan with respect to the half-life of the candidate biomarkers; 3-implementing and validating the sampling procedures and analytical methods; 4-selecting the best suitable biomarkers to be measured in the field. Each study participant is surveyed every day during the 6–8 h work-shifts for two consecutive weeks. The field study has an implementation research designe that enabled us to demonstrate the applicability of the standardized protocol for biomarker measurements in occupational settings while also assessing the biomarkers’ validity. ROBoCoP will focus on particulate matter (PM) exposure measurements, exposure biomarkers and a series of effect biomarkers, including markers of lipoperoxidation: 8-isoprostane, malondialdehyd in exhaled breath condensate (EBC) and urine, potential markers of nitrosative stress: NO₂⁻, NO₃⁻ and formate anion in EBC; markers of DNA oxidation: 8-hydroxy-2’deoxyguanosine in EBC and urine, marker of genotoxicity: micronuclei in buccal cells, and oxidative potential in exhaled air (OPEA). OPEA appears particularly promising as a clinical biomarker for detecting COPD, and will be tested independently and as part of a biomarker panel. COPD diagnosis will be performed by an experienced occupational physician according to international diagnostic standards and confirmed by a pulmonologist.

This research will include approximatively 300 underground subway workers randomly selected from the personnel registry of a large Parisian transport company. Underground subways are suggested as the most PM polluted urban transport environment. We believe this occupational exposure is relevant for biomonitoring of workers and early detection of respiratory diseases.

Household Food Insecurity, Lung Function, and COPD in US Adults

Increasing epidemiological evidence suggests that optimal diet quality helps to improve preservation of lung function and to reduce chronic obstructive pulmonary disease (COPD) risk, but no study has investigated the association of food insecurity (FI) and lung health in the general population. Using data from a representative sample of US adults who participated in the National Health and Nutrition Examination Survey (NHANES) 2007–2012 cycles, we investigated the association between FI with lung function and spirometrically defined COPD in 12,469 individuals aged ≥ 18 years of age. FI (high vs. low) was defined using the US Department of Agriculture’s Food Security Scale). Population-weighted adjusted regression models were used to investigate associations between FI, and forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), their ratio, and spirometrically defined restriction (FVC below the lower limit of normal) and airflow obstruction (COPD). The prevalence of household FI was 13.2%. High household FI was associated with lower FVC (adjusted β-coefficient −70.9 mL, 95% CI −116.6, −25.3), and with higher odds (OR) of spirometric restriction (1.02, 95% CI 1.00, 1.03). Stratified analyses showed similar effect sizes within specific ethnic groups. High FI was associated with worse lung health in a nationally representative sample of adults in the US.

Benefits Conferred by Peer-Support Nursing Intervention to Pulmonary Function and Quality of Life in Nonsmoking Patients with COPD

Objective

Peer support is a concept of substantial significance to health scientists and practitioners today due to its focus shifting from disease treatment to health promotion. Effective incorporation peer relationships in support-enhancing interventions could improve quality care and health outcomes. More and more cases of chronic obstructive pulmonary disease (COPD) have been diagnosed in nonsmokers. In this study, the effects of peer-support nursing intervention on the pulmonary function and quality of life of nonsmoking patients with COPD were investigated.

Methods

A total of 100 COPD nonsmoking patients admitted to our hospital from October 2018 to October 2020 were selected as study subjects. All nonsmoking patients were in accordance with the guidelines of COPD diagnosis and treatment issued by the Respiratory Medicine Branch of Chinese Medical Association, and they were not in the habit of smoking. According to the different interventions, the nonsmoking patients were divided into the control group (n = 50) and the observation group (n = 50). Among them, nonsmoking patients in the control group received routine care, and nonsmoking patients in the observation group received routine care and peer-support nursing. The difference on the scores of social support, self-management efficacy, healthy lifestyle, and the distance of six-minute walking were to be compared between the two groups before and after the intervention.

Results

There was no significant statistical difference on the general information between the two groups in terms of age, gender, and course of disease (P > 0.05). Before intervention, the social support score involving subjective support, objective support, utilization of support, and total score revealed slight difference between the two groups (P > 0.05). However, after the intervention, the subjective support, utilization of support, and total score remained statistically different between the two groups (P < 0.05), and the objective support showed no significant difference between the two groups (P > 0.05). Before intervention, there was no statistical difference in the self-management efficacy scores such as positive attitude, stress reduction, self-decision-making, and total score between the two groups (P > 0.05). After the intervention, the two groups indicated statistical difference in the self-management efficacy scores (P < 0.05). Before intervention, there was no significant difference between the two groups in the healthy lifestyle score in terms of health responsibility, self-realization, interpersonal support, and stress management (P > 0.05), and the abovementioned outcome measures indicated significant difference between the two groups after intervention (P < 0.05). There was no statistical difference in six-minute walking distance between the two groups before the intervention (P > 0.05), but after the intervention, the observation group revealed a significantly longer distance of six-minute walking compared to the control group (P < 0.05).

Conclusion

These data suggest that peer-support nursing intervention can effectively improve pulmonary function and quality of life of nonsmoking patients with COPD.

Acute Effects of Heated Tobacco Product (IQOS) Aerosol Inhalation on Lung Tissue Damage and Inflammatory Changes in the Lungs

INTRODUCTION

Emerging heated tobacco products (HTPs) were designed to reduce exposure to toxicants from cigarette smoke (CS) by avoiding burning tobacco and instead heating tobacco. We studied the effects of short-term inhalation of aerosols emitted from HTP called IQOS, on lung damage and immune-cell recruitment to the lungs in mice.

METHODS

Numerous markers of lung damage and inflammation including albumin and lung immune-cell infiltrates, proinflammatory cytokines, and chemokines were quantified in lungs and bronchoalveolar (BAL) fluid from IQOS, CS, or air-exposed (negative control) mice.

RESULTS

Importantly, as a surrogate marker of lung epithelial-cell damage, we detected significantly increased levels of albumin in the BAL fluid of both HTP- and CS-exposed mice compared with negative controls. Total numbers of leukocytes infiltrating the lungs were equivalent following both IQOS aerosols and CS inhalation and significantly increased compared with air-exposed controls. We also observed significantly increased numbers of CD4+IL-17A+ T cells, a marker of a T-cell immune response, in both groups compared with air controls; however, numbers were the highest following CS exposure. Finally, the numbers of CD4+RORγt+ T cells, an inflammatory T-cell subtype expressing the transcription factor that is essential for promoting differentiation into proinflammatory Th17 cells, were significantly augmented in both groups compared with air-exposed controls. Levels of several cytokines in BAL were significantly elevated, reflecting a proinflammatory milieu.

CONCLUSIONS

Our study demonstrates that short-term inhalation of aerosols from IQOS generates damage and proinflammatory changes in the lung that are substantially similar to that elicited by CS exposure.

IMPLICATIONS

Exposure of mice to IQOS, one of the candidate modified-risk tobacco products, induces inflammatory immune-cell accumulation in the lungs and augments the levels of proinflammatory cytokines and chemokines in the BAL fluid. Such an exacerbated pulmonary proinflammatory microenvironment is associated with lung epithelial-cell damage in IQOS-exposed mice, suggesting a potential association with the impairment of lung function.

Differences between cigarette smoking and biomass smoke exposure: An in silico comparative assessment of particulate deposition in the lungs

Cigarette smoking and biomass smoke are the two main environmental risk factors of chronic obstructive pulmonary disease (COPD) worldwide. However, it remains unclear why these exposures result in two different disease phenotypes. In this study, we assessed the lung deposition from biomass and cigarette smoke exposures and examined whether differences due to inherently different particle size distributions and inhalation conditions may contribute to the differences between biomass- and tobacco-related COPD phenotypes. Using high-fidelity three-dimensional computational fluid-particle dynamics in a representative upper airway geometry, coupled to one-dimensional models of the lower airways, we computed total deposited doses and examined regional deposition patterns based on exposure data from a randomized control trial in Peru and from the literature for biomass and mainstream cigarette smoke, respectively. Our results showed that intrathoracic deposition was higher in cigarette smoking, with 36.8% of inhaled biomass smoke particles and 57.7% of cigarette smoke particles depositing in the intrathoracic airways. We observed higher fractions of cigarette smoke particles in the last few airway generations, which could explain why cigarette smoking is associated with more emphysema than biomass smoke exposure. Mean daily deposited dose was two orders of magnitude higher in cigarette smoking. Lobar distributions of the deposited dose also differed, with the left lower and right upper lobes receiving the highest doses of biomass and cigarette smoke particles, respectively. Our findings suggest that the differences between biomass- and tobacco-related COPD could, at least in part, be due to differences in total and regional lung deposition of biomass and cigarette smoke.

High eosinophil counts predict decline in FEV1: results from the CanCOLD study

INTRODUCTION

The aim of this study was to examine the association between blood eosinophil levels and the decline in lung function in individuals aged >40 years from the general population.

METHODS

The study evaluated the eosinophil counts from thawed blood in 1120 participants (mean age 65 years) from the prospective population-based Canadian Cohort of Obstructive Lung Disease (CanCOLD) study. Participants answered interviewer-administered respiratory questionnaires and performed pre-/post-bronchodilator spirometric tests at 18-month intervals; computed tomography (CT) imaging was performed at baseline. Statistical analyses to describe the relationship between eosinophil levels and decline in forced expiratory volume in 1 s (FEV₁) were performed using random mixed-effects regression models with adjustments for demographics, smoking, baseline FEV₁, ever-asthma and history of exacerbations in the previous 12 months. CT measurements were compared between eosinophil subgroups using ANOVA.

RESULTS

Participants who had a peripheral eosinophil count of ≥300 cells·µL^-1 (n=273) had a greater decline in FEV₁ compared with those with eosinophil counts of <150 cells·µL^-1 (n=430; p=0.003) (reference group) and 150-<300 cells·µL^-1 (n=417; p=0.003). The absolute change in FEV₁ was -32.99 mL·year^-1 for participants with eosinophil counts <150 cells·µL^-1; -38.78 mL·year^-1 for those with 150-<300 cells·µL^-1 and -67.30 mL·year^-1 for participants with ≥300 cells·µL^-1. In COPD, higher eosinophil count was associated with quantitative CT measurements reflecting both small and large airway abnormalities.

CONCLUSION

A blood eosinophil count of ≥300 cells·µL^-1 is an independent risk factor for accelerated lung function decline in older adults and is related to undetected structural airway abnormalities.

Innate Immune Responses and Pulmonary Diseases

Innate immunity is the first defense line of the host against various infectious pathogens, environmental insults, and other stimuli causing cell damages. Upon stimulation, pattern recognition receptors (PRRs) act as sensors to activate innate immune responses, containing NF-κB signaling, IFN response, and inflammasome activation. Toll-like receptors (TLRs), retinoic acid-inducible gene I-like receptors (RLRs), NOD-like receptors (NLRs), and other nucleic acid sensors are involved in innate immune responses. The activation of innate immune responses can facilitate the host to eliminate pathogens and maintain tissue homeostasis. However, the activity of innate immune responses needs to be tightly controlled to ensure the optimal intensity and duration of activation under various contexts. Uncontrolled innate immune responses can lead to various disorders associated with aberrant inflammatory response, including pulmonary diseases such as COPD, asthma, and COVID-19. In this chapter, we will have a broad overview of how innate immune responses function and the regulation and activation of innate immune response at molecular levels as well as their contribution to various pulmonary diseases. A better understanding of such association between innate immune responses and pulmonary diseases may provide potential therapeutic strategies.

Nicotinic α7 acetylcholine receptor (α7nAChR) in human airway smooth muscle

Diseases such as asthma are exacerbated by inflammation, cigarette smoke and even nicotine delivery devices such as e-cigarettes. However, there is currently little information on how nicotine affects airways, particularly in humans, and changes in the context of inflammation or asthma. Here, a longstanding assumption is that airway smooth muscle (ASM) that is key to bronchoconstriction has muscarinic receptors while nicotinic receptors (nAChRs) are only on airway neurons. In this study, we tested the hypothesis that human ASM expresses α7nAChR and explored its profile in inflammation and asthma using ASM of non-asthmatics vs. mild-moderate asthmatics. mRNA and western analysis showed the α7 subunit is most expressed in ASM cells and further increased in asthmatics and smokers, or by exposure to nicotine, cigarette smoke or pro-inflammatory cytokines TNFα and IL-13. In these effects, signaling pathways relevant to asthma such as NFκB, AP-1 and CREB are involved. These novel data demonstrate the expression of α7nAChR in human ASM and suggest their potential role in asthma pathophysiology in the context of nicotine exposure.

Childhood Origins of Adult Lung Disease as Opportunities for Prevention

Prenatal and childhood exposures have been shown to impact lung development, lung function trajectory, and incidence and prevalence of respiratory disease. Early life may serve as a window of susceptibility to such exposures, with the potential to influence lifelong respiratory health. Risk factors encountered in early life with potentially durable impact on lung health include prematurity, respiratory viral illness, allergen sensitization and exposure, tobacco use and exposure, indoor and outdoor pollution, diet, and obesity. These exposures vary in the extent to which they are modifiable, and interventions aimed at reducing harmful exposures range from individual-level behavior modification to policy initiatives implemented to promote population health. For many exposures, including tobacco-related exposures, multilevel interventions are needed. Future research is needed to provide insight as to early-life interventions to promote optimal lung growth and prevent development of chronic respiratory disease. Clinicians should play an active role, assisting individual patients in avoiding known detrimental exposures including maternal smoking during pregnancy and initiation of active smoking. Clinicians can be empowered by evidence to support policies promoting reduction of population-level risk factors, such as restriction on electronic cigarette sales and legislation to uphold air quality standards, to encourage attainment of maximal lung function and reduce risk of chronic lung disease.

Exosomal lncRNA TCONS_00064356 derived from injured alveolar epithelial type II cells affects the biological characteristics of mesenchymal stem cells

Chronic obstructive pulmonary disease (COPD) is a prevalent respiratory disease, and a leading cause of morbidity and mortality worldwide. There is still a lack of effective treatment to improve pulmonary structural abnormality and reverse the progression of COPD. Mesenchymal stem cell (MSC)-based therapies have attracted much attention and show promising clinical application prospects in COPD treatment. Understanding the communication between injured alveolar cells and MSCs will help us improve the efficiency of MSC-based therapies. Here, we showed that exosomes secreted by injured alveolar epithelial type II (AEC-II) cells could promote the proliferation and migration of MSCs, accompanied with increased expression levels of genes related to mitochondrial synthesis and transfer. Moreover, we identified 21 significantly dysregulated exosomal lncRNAs (16 upregulated and 5 downregulated) using lncRNA sequencing. In addition, we found that lncRNA TCONS_00064356-overexpressing MSCs showed increased proliferation and migration capacities and upregulated expression levels of the genes related to mitochondrial synthesis and transfer. Together, our study uncovers a new potential exosome-mediated communication pathway between injured AEC-II cells and MSCs and provides new targets and ideas for improving the efficiency of MSC-based therapies for COPD.

Glutathione S-transferases and their implications in the lung diseases asthma and chronic obstructive pulmonary disease: Early life susceptibility?

Our lungs are exposed daily to airborne pollutants, particulate matter, pathogens as well as lung allergens and irritants. Exposure to these substances can lead to inflammatory responses and may induce endogenous oxidant production, which can cause chronic inflammation, tissue damage and remodeling. Notably, the development of asthma and Chronic Obstructive Pulmonary Disease (COPD) is linked to the aforementioned irritants. Some inhaled foreign chemical compounds are rapidly absorbed and processed by phase I and II enzyme systems critical in the detoxification of xenobiotics including the glutathione-conjugating enzymes Glutathione S-transferases (GSTs). GSTs, and in particular genetic variants of GSTs that alter their activities, have been found to be implicated in the susceptibility to and progression of these lung diseases. Beyond their roles in phase II metabolism, evidence suggests that GSTs are also important mediators of normal lung growth. Therefore, the contribution of GSTs to the development of lung diseases in adults may already start in utero, and continues through infancy, childhood, and adult life. GSTs are also known to scavenge oxidants and affect signaling pathways by protein-protein interaction. Moreover, GSTs regulate reversible oxidative post-translational modifications of proteins, known as protein S-glutathionylation. Therefore, GSTs display an array of functions that impact the pathogenesis of asthma and COPD.

In this review we will provide an overview of the specific functions of each class of mammalian cytosolic GSTs. This is followed by a comprehensive analysis of their expression profiles in the lung in healthy subjects, as well as alterations that have been described in (epithelial cells of) asthmatics and COPD patients. Particular emphasis is placed on the emerging evidence of the regulatory properties of GSTs beyond detoxification and their contribution to (un)healthy lungs throughout life. By providing a more thorough understanding, tailored therapeutic strategies can be designed to affect specific functions of particular GSTs.

Nutritional immunity: the impact of metals on lung immune cells and the airway microbiome during chronic respiratory disease

Nutritional immunity is the sequestration of bioavailable trace metals such as iron, zinc and copper by the host to limit pathogenicity by invading microorganisms. As one of the most conserved activities of the innate immune system, limiting the availability of free trace metals by cells of the immune system serves not only to conceal these vital nutrients from invading bacteria but also operates to tightly regulate host immune cell responses and function. In the setting of chronic lung disease, the regulation of trace metals by the host is often disrupted, leading to the altered availability of these nutrients to commensal and invading opportunistic pathogenic microbes. Similarly, alterations in the uptake, secretion, turnover and redox activity of these vitally important metals has significant repercussions for immune cell function including the response to and resolution of infection. This review will discuss the intricate role of nutritional immunity in host immune cells of the lung and how changes in this fundamental process as a result of chronic lung disease may alter the airway microbiome, disease progression and the response to infection.

Impaired Respiratory Health and Life Course Transitions From Health to Chronic Lung Disease

Primary prevention and interception of chronic lung disease are essential in the effort to reduce the morbidity and mortality caused by respiratory conditions. In this review, we apply a life course approach that examines exposures across the life span to identify risk factors that are associated with not only chronic lung disease but also an intermediate phenotype between ideal lung health and lung disease, termed "impaired respiratory health." Notably, risk factors such as exposure to tobacco smoke and air pollution, as well as obesity and physical fitness, affect respiratory health across the life course by being associated with both abnormal lung growth and lung function decline. We then discuss the importance of disease interception and identifying those at highest risk of developing chronic lung disease. This work begins with understanding and detecting impaired respiratory health, and we review several promising molecular biomarkers, predictive symptoms, and early imaging findings that may lead to a better understanding of this intermediate phenotype.

Predicting Individual Survival after Curative Esophagectomy for Squamous Cell Carcinoma of Esophageal

BACKGROUND

Esophageal cancer is one of the leading causes of cancer-related death worldwide. Despite the significant progress in the overall treatment of esophageal cancer in recent years, the prognosis for patients who require surgery remains poor.

METHODS

The present study investigated the clinicopathological features of 503 patients who underwent radical esophagectomy at Huashan Hospital of Fudan University between January 2005 and January 2015. Nomograms that predicted the esophageal squamous cell carcinoma (ESCC) survival rates were established using the Cox proportional hazard regression model. Discrimination and calibration, which were calculated after bootstrapping, were used as a measure of accuracy.

RESULTS

Multivariate analyses were used to select five independent prognostic variables and build the nomogram. These variables were pathological T stage, pathological N factor, rate of positive LNs, history of chronic obstructive pulmonary disease (COPD) and postoperative sepsis. The nomogram was built to predict the rates for overall survival (OS) and disease-free survival (DFS). The concordance index for the nomogram prediction for OS and DFS was 0.720 and 0.707, respectively. Compared to the conventional TNM staging system, the nomogram had better predictive accuracy for survival (OS 0.720 vs. 0.672, P < 0.001; DFS 0.707 vs. 0.667; P < 0.001).

CONCLUSIONS

The present study incorporated pathological T stage, pathological N factor, rate of positive LNs, history of COPD, and postoperative sepsis into a nomogram to predict the OS and DFS of ESCC patients. This practical system may help clinicians in both decision-making and clinical study design. The assessment of lung function for patients with COPD preoperative, and the control of disease progression are needed. Furthermore, the postoperative infection of patients should be controlled. Further studies may help to extend the validation of this method and improve the model through parameter optimization.

Drug Use and Cancer Risk: A Drug-Wide Association Study (DWAS) in Norway

BACKGROUND

Population-based pharmaco-epidemiologic studies are used to assess postmarketing drug safety and discover beneficial effects of off-label drug use. We conducted a drug-wide association study (DWAS) to screen for associations between prescription drugs and cancer risk.

METHODS

This registry-based, nested case-control study, 1:10 matched on age, sex, and date of diagnosis of cases, comprises approximately 2 million Norwegian residents, including their drug history from 2004 to 2014. We evaluated the association between prescribed drugs, categorized according to the anatomical therapeutic chemical (ATC) classification system, and the risk of the 15 most common cancer types, overall and by histology. We used stratified Cox regression, adjusted for other drug use, comorbidity, county, and parity, and explored dose-response trends.

RESULTS

We found 145 associations among 1,230 drug-cancer combinations on the ATC2-level and 77 of 8,130 on the ATC4-level. Results for all drug-cancer combinations are presented in this article and an online tool (https://pharmacoepi.shinyapps.io/drugwas/). Some associations have been previously reported, that is, menopausal hormones and breast cancer risk, or are likely confounded, that is, chronic obstructive pulmonary diseases and lung cancer risk. Other associations were novel, that is, inverse association between proton pump inhibitors and melanoma risk, and carcinogenic association of propulsives and lung cancer risk.

CONCLUSIONS

This study confirmed previously reported associations and generated new hypotheses on possible carcinogenic or chemopreventive effects of prescription drugs. Results from this type of explorative approach need to be validated in tailored epidemiologic and preclinical studies.

IMPACT

DWAS studies are robust and important tools to define new drug-cancer hypotheses.See related commentary by Wang and Gadalla, p. 597.

RAGE and TLR4 differentially regulate airway hyperresponsiveness: Implications for COPD

BACKGROUND

The receptor for advanced glycation end products (RAGE) and Toll-like receptor 4 (TLR4) is implicated in COPD. Although these receptors share common ligands and signalling pathways, it is not known whether they act in concert to drive pathological processes in COPD. We examined the impact of RAGE and/or TLR4 gene deficiency in a mouse model of COPD and also determined whether expression of these receptors correlates with airway neutrophilia and airway hyperresponsiveness (AHR) in COPD patients.

METHODS

We measured airway inflammation and AHR in wild-type, RAGE^-/- , TLR4^-/- and TLR4^-/- RAGE^-/- mice following acute exposure to cigarette smoke (CS). We also examined the impact of smoking status on AGER (encodes RAGE) and TLR4 bronchial gene expression in patients with and without COPD. Finally, we determined whether expression of these receptors correlates with airway neutrophilia and AHR in COPD patients.

RESULTS

RAGE^-/- mice were protected against CS-induced neutrophilia and AHR. In contrast, TLR4^-/- mice were not protected against CS-induced neutrophilia and had more severe CS-induced AHR. TLR4^-/- RAGE^-/- mice were not protected against CS-induced neutrophilia but were partially protected against CS-induced mediator release and AHR. Current smoking was associated with significantly lower AGER and TLR4 expression irrespective of COPD status, possibly reflecting negative feedback regulation. However, consistent with preclinical findings, AGER expression correlated with higher sputum neutrophil counts and more severe AHR in COPD patients. TLR4 expression did not correlate with neutrophilic inflammation or AHR.

CONCLUSIONS

Inhibition of RAGE but not TLR4 signalling may protect against airway neutrophilia and AHR in COPD.

Lifetime Risk Factors for Pre- and Post-Bronchodilator Lung Function Decline. A Population-based Study

Rationale: Interactions between early life and adult insults on lung function decline are not well understood, with most studies investigating prebronchodilator (pre-BD) FEV₁ decline.Objectives: To investigate relationships between adult risk factors and pre- and post-BD lung function decline and their potential effect modification by early life and genetic factors.Methods: Multiple regression was used to examine associations between adult exposures (asthma, smoking, occupational exposures, traffic pollution, and obesity) and decline in both pre- and post-BD spirometry (forced expiratory volume in 1 s [FEV₁], forced vital capacity [FVC], and FEV₁/FVC) between ages 45 and 53 years in the Tasmanian Longitudinal Health Study (n = 857). Effect modification of these relationships by childhood respiratory risk factors, including low childhood lung function and GST (glutathione S-transferase) gene polymorphisms, was investigated.Results: Baseline asthma, smoking, occupational exposure to vapors/gases/dusts/fumes, and living close to traffic were associated with accelerated decline in both pre- and post-BD FEV₁. These factors were also associated with FEV₁/FVC decline. Occupational exposure to aromatic solvents was associated with pre-BD but not post-BD FEV₁ decline. Maternal smoking accentuated the effect of personal smoking on pre- and post-BD FEV₁ decline. Lower childhood lung function and having the GSTM1 null allele accentuated the effect of occupational exposure to vapors/gases/dusts/fumes and personal smoking on post-BD FEV₁ decline. Incident obesity was associated with accelerated decline in FEV₁ and more pronounced in FVC.Conclusions: This study provides new evidence for accentuation of individual susceptibility to adult risk factors by low childhood lung function, GSTM1 genotype, and maternal smoking.