Adult Life-Course Trajectories of Lung Function and the Development of Emphysema: The CARDIA Lung Study

Time-dependent gene-environment interactions are essential drivers of asthma initiation and persistence

Asthma is a clinical syndrome caused by heterogeneous underlying mechanisms with some of them having a strong genetic component. It is known that up to 82% of atopic asthma has a genetic background with the rest being influenced by environmental factors that cause epigenetic modification(s) of gene expression. The interaction between the gene(s) and the environment has long been regarded as the most likely explanation of asthma initiation and persistence. Lately, much attention has been given to the time frame the interaction occurs since the host response (immune or biological) to environmental triggers, differs at different developmental ages. The integration of the time variant into asthma pathogenesis is appearing to be equally important as the gene(s)-environment interaction. It seems that, all three factors should be present to trigger the asthma initiation and persistence cascade. Herein, we introduce the importance of the time variant in asthma pathogenesis and emphasize the long-term clinical significance of the time-dependent gene-environment interactions in childhood.

Distinct trajectories of lung function from childhood to mid-adulthood

RATIONALE

Life course trajectories of lung function development and decline influence the risk for lung disease but are poorly documented.

OBJECTIVE

To document lung function trajectories from childhood to mid-adult life.

METHODS

We modelled forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC at ages 9, 11, 13, 15, 18, 21, 26, 32, 38 and 45 years from a population-based cohort using latent profile analysis to identify distinct subgroups of participants with similar lung function trajectories. Regression analyses were used to assess associations between the trajectories, early life factors and postbronchodilator airflow obstruction at age 45.

RESULTS

Among 865 participants with ≥6 measures of lung function, we identified 10 distinct FEV1 trajectories. Most were approximately parallel except for a childhood airway hyper-responsiveness-related persistently low trajectory (3% of study population); two accelerated-decline trajectories, one of which (8%) was associated with smoking and higher adult body mass index (BMI) and a catch-up trajectory (8%). Findings for FEV1/FVC trajectories were similar. Nine trajectories were identified for FVC: most were also approximately parallel except for a higher BMI-related accelerated-decline trajectory. The three FEV1 trajectories leading to the lowest FEV1 values comprised 19% of the cohort but contributed 55% of airflow obstruction at age 45.

CONCLUSIONS

Lung function trajectories to mid-adult life are largely established before adolescence, with a few exceptions: a childhood airway hyper-responsiveness-related persistently low trajectory, which starts low and gets worse with age, and accelerated adult decline trajectories associated with smoking and obesity. Adverse trajectories are associated with a high risk of airflow obstruction in mid-adult life.

Associations of a plant-centered diet and lung function across early to mid-adulthood: The CARDIA Lung Study

BACKGROUND

Lung function throughout adulthood predicts morbidity and mortality even among adults without chronic respiratory disease. Diet quality may represent a modifiable risk factor for lung function impairment later in life. We investigated associations between nutritionally-rich plant-centered diet and lung function across early and middle adulthood from the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

METHODS

Diet was assessed at baseline and years 7 and 20 of follow-up using the validated CARDIA diet history questionnaire. Plant-centered diet quality was scored using the validated A Priori Diet Quality Score (APDQS), which weights food groups to measure adherence to a nutritionally-rich plant-centered diet for 20 beneficially rated foods and 13 adversely rated foods. Scores were cumulatively averaged over follow-up and categorized into quintiles. The primary outcome was lung function decline, including forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), measured at years 0, 2, 5, 10, 20, and 30. We estimated the association of APDQS with annual pulmonary function changes and cross-sectional differences in a repeated measures regression model, adjusting for clinically relevant covariates.

RESULTS

The study included 3,787 Black and White men and women aged 18-30 in 1985-86 and followed for 30 years. In multivariable repeated measures regression models, individuals in the lowest APDQS quintile (poorest diet) had declines in FEV1 that were 1.6 ml/year greater than individuals in the highest quintile (35.0 vs. 33.4 ml/year, ß ± SE per 1 SD change APDQS 0.94 ± 0.36, p = 0.009). Additionally, declines in FVC were 2.4 ml/year greater in the lowest APDQS quintile than those in the highest quintile (37.0 vs 34.6 ml/year, ß ± SE per 1 SD change APDQS 1.71 ± 0.46, p < 0.001). The association was not different between never and ever smokers (pint = 0.07 for FVC and 0.32 for FEV1). In sensitivity analyses where current asthma diagnosis and cardiorespiratory fitness were further adjusted, results remained similar. Cross-sectional analysis at each exam year also showed significant differences in lung function according to diet after covariate adjustment.

CONCLUSIONS

In this 30-year longitudinal cohort study, long-term adherence to a nutritionally-rich plant-centered diet was associated with cross-sectional differences in lung function as well as slower decline in lung function, highlighting diet quality as a potential treatable trait supporting long-term lung health.

Implications of Mean Pulmonary Arterial Wedge Pressure Trajectories in Pulmonary Arterial Hypertension

Rationale: The mean pulmonary arterial wedge pressure (mPAWP) is the critical hemodynamic factor differentiating group 1 pulmonary arterial hypertension (PAH) from group 2 pulmonary hypertension associated with left heart disease. Despite the discrepancy between the mPAWP upper physiologic normal and current PAH definitions, the implications of the initial mPAWP for PAH clinical trajectory are poorly understood. Objectives: To model longitudinal mPAWP trajectories in PAH over 10 years and examine the clinical and hemodynamic factors associated with trajectory membership. Methods: Adult patients with PAH with two or more right heart catheterizations were identified from a multiinstitution healthcare system in eastern Massachusetts. mPAWP trajectories were constructed via group-based trajectory modeling. Feature selection was performed in least absolute shrinkage and selection operator regression. Logistic regression was used to assess associations between trajectory membership, baseline characteristics, and transplant-free survival. Measurements and Main Results: Among 301 patients with PAH, there were two distinct mPAWP trajectories, termed "mPAWP-high" (n = 71; 23.6%) and "mPAWP-low" (n = 230; 76.4%), based on the ultimate mPAWP value. Initial mPAWP clustered around median 12 mm Hg (interquartile range [IQR], 8-14 mm Hg) in the mPAWP-high and 9 mm Hg (IQR, 6-11 mm Hg) in the mPAWP-low trajectories (P < 0.001). After feature selection, initial mPAWP ⩾12 mm Hg predicted an mPAWP-high trajectory (odds ratio, 3.2; 95% confidence interval, 1.4-6.1; P = 0.0006). An mPAWP-high trajectory was associated with shorter transplant-free survival (vs. mPAWP-low, median, 7.8 vs. 11.3 yr; log-rank P = 0.017; age-adjusted P = 0.217). Conclusions: Over 10 years, the mPAWP followed two distinct trajectories, with 25% evolving into group 2 pulmonary hypertension physiology. Using routine baseline data, longitudinal mPAWP trajectory could be predicted accurately, with initial mPAWP ⩾12 mm Hg as one of the strongest predictors.

Clinical relevance of lung function trajectory clusters in middle-aged and older adults

Background

The determinants and health outcomes of lung function trajectories in adults among the general population are poorly understood. We aimed to identify and characterise clusters of lung function trajectories in adults aged ≥45 years.

Methods

Gaussian finite-mixture modelling was applied to baseline and annualised change of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio z-scores in participants of the Rotterdam Study, a prospective population-based cohort study, with repeated spirometry (n=3884; mean±sd age 64.7±8.9 years). Longitudinal outcomes were all-cause mortality, respiratory outcomes (symptoms, COPD (FEV1/FVC <0.7 in absence of asthma), preserved ratio impaired spirometry (PRISm; FEV1/FVC ≥0.7 and FEV1 or FVC <80%)), smoking cessation and weight changes. Independent risk factors, including genetics, were identified by multiple logistic regression.

Results

We identified eight trajectory clusters, with the reference group having persistently normal spirometry (prevalence 42.8%). Three clusters showed higher mortality, adjusted for confounders: 1) the persistently low FEV1 cluster (prevalence 6.8%, hazard ratio (HR) 1.71, 95% CI 1.37-2.13); 2) rapid FEV1 decliners (prevalence 4.6%, HR 1.48, 95% CI 1.10-1.99); and 3) FVC decliners (prevalence 3.7%, HR 1.49, 95% CI 1.09-2.03). In contrast, FVC improvers (prevalence 6.7%, HR 0.61, 95% CI 0.41-0.90) and persistently high FEV1 (prevalence 29.2%, HR 0.82, 95% CI 0.69-0.98) were protective trajectory clusters. Clusters were characterised by differences in genetic predisposition (polygenic scores of FEV1 and FEV1/FVC), demographics, cigarette smoking, respiratory symptoms (chronic cough, wheezing and dyspnoea), cardiovascular factors (body mass index, hypertension and heart failure) and serum C-reactive protein levels. Frailty, weight changes and the development of respiratory symptoms, COPD and PRISm were significantly associated with trajectory clusters.

Conclusions

This study reveals clinically relevant lung function trajectory clusters in older adults of the general population.

Lung Function Trajectories and Associated Mortality among Adults with and without Airway Obstruction

Rationale: Spirometry is essential for diagnosis and assessment of prognosis in patients with chronic obstructive pulmonary disease (COPD). Objectives: To identify FEV1 trajectories and their determinants on the basis of annual spirometry measurements among individuals with and without airway obstruction (AO) and to assess mortality in relation to trajectories. Methods: From 2002 through 2004, individuals with AO (FEV1/VC < 0.70, n = 993) and age- and sex-matched nonobstructive (NO) referents were recruited from population-based cohorts. Annual spirometry until 2014 was used in joint-survival latent-class mixed models to identify lung function trajectories. Mortality data were collected during 15 years of follow-up. Measurements and Main Results: Three trajectories were identified among the subjects with AO and two among the NO referents. Trajectory membership was driven by baseline FEV1% predicted (FEV1%pred) in both groups and also by pack-years in subjects with AO and current smoking in NO referents. Longitudinal FEV1%pred depended on baseline FEV1%pred, pack-years, and obesity. The trajectories were distributed as follows: among individuals with AO, 79.6% in AO trajectory 1 (FEV1 high with normal decline), 12.8% in AO trajectory 2 (FEV1 high with rapid decline), and 7.7% in AO trajectory 3 (FEV1 low with normal decline) (mean, 27, 72, and 26 ml/yr, respectively) and, among NO referents, 96.7% in NO trajectory 1 (FEV1 high with normal decline) and 3.3% in NO trajectory 2 (FEV1 high with rapid decline) (mean, 34 and 173 ml/yr, respectively). Hazard for death was increased for AO trajectories 2 (hazard ratio [HR], 1.56) and 3 (HR, 3.45) versus AO trajectory 1 and for NO trajectory 2 (HR, 2.99) versus NO trajectory 1. Conclusions: Three different FEV1 trajectories were identified among subjects with AO and two among NO referents, with different outcomes in terms of FEV1 decline and mortality. The FEV1 trajectories among subjects with AO and the relationship between low FVC and trajectory outcome are of particular clinical interest.

Longitudinal Changes and Association of Respiratory Symptoms with Preserved Ratio Impaired Spirometry (PRISm): The Nagahama Study

Rationale: Subjects with preserved ratio impaired spirometry (PRISm) experience increased respiratory symptoms, although they present heterogeneous characteristics. However, the longitudinal changes in these symptoms and respiratory function are not well known. Objectives: To investigate PRISm from the viewpoint of respiratory symptoms in a longitudinal, large-scale general population study. Methods: The Nagahama study included 9,789 inhabitants, and a follow-up evaluation was conducted after 5 years. Spirometry and self-administered questionnaires regarding respiratory symptoms, including prolonged cough, sputum and dyspnea, and comorbidities were conducted. Results: In total, 9,760 subjects were analyzed, and 438 subjects had PRISm. Among the subjects with PRISm, 53% presented with respiratory symptoms; dyspnea was independently associated with PRISm. Follow-up assessment revealed that 73% of the subjects with PRISm with respiratory symptoms were consistently symptomatic, whereas 39% of the asymptomatic subjects with PRISm developed respiratory symptoms within 5 years. In addition, among subjects with respiratory symptoms without airflow limitation at baseline, PRISm was a risk factor for the development of airflow limitation independent of smoking history and comorbidities. Conclusions: This study demonstrated that 53% of the subjects with PRISm had respiratory symptoms; dyspnea was a distinct characteristic of PRISm. Approximately three-fourths of the symptomatic subjects with PRISm consistently complained of respiratory symptoms within 5 years. Together with our result that PRISm itself is an independent risk factor for the development of chronic obstructive pulmonary disease among subjects with respiratory symptoms, the clinical course of subjects with PRISm with symptoms requires careful monitoring.

Current evidence on supranormal lung function: A call for longitudinal research to optimize lung health

See related article

Lung Function Decline in Young Adulthood and Coronary Artery Calcium Progression in Midlife

BACKGROUND

Reduced lung function has been linked to cardiovascular disease, but population-based evidence on the relationship between lung function decline and coronary artery calcium (CAC) progression is rare.

METHODS

A total of 2694 participants (44.7% men) with a mean ± standard deviation age of 40.4 ± 3.6 years from the Coronary Artery Risk Development in Young Adults (CARDIA) were included. The rates of decline in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) over a 20-year period were calculated for each participant and categorized into quartiles. The primary outcome was CAC progression.

RESULTS

During a mean follow-up of 8.9 years, 455 (16.9%) participants had CAC progression. After adjusting for traditional cardiovascular risk factors, the hazard ratios (95% confidence intervals [CIs]) for CAC progression were higher for participants in the 2nd (Q2), 3rd (Q3), and highest quartiles (Q4) of FVC decline compared with those in the lowest quartile (Q1): 1.366 (1.003-1.861), 1.412 (1.035-1.927), and 1.789 (1.318-2.428), respectively. Similar trends were observed for the association between FEV1 and CAC progression. The association remained robust across a series of sensitivity analyses and all subgroups.

CONCLUSIONS

A faster decline in FVC or FEV1 during young adulthood is independently associated with an increased risk of CAC progression in midlife. Maintaining optimal lung function during young adulthood may improve future cardiovascular health.

Associations between GrimAge acceleration and pulmonary function in the Coronary Artery Risk Development in Young Adults (CARDIA) study

Background: The objective of this research was to determine whether pulmonary function is associated with epigenetic aging (GrimAge) and whether GrimAge predicts emphysema. Methods: This prospective study examined 1042 participants enrolled as part of a community-based longitudinal cohort. The cross-sectional associations between pulmonary function and GrimAge, measured at study year (Y) 20 (participant ages 40-45 years), and prospective associations with emphysema at Y25 were examined. Results: At Y20, forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) were negatively associated with GrimAge; for Y0-Y10 cumulative measures, only the FEV1/FVC ratio was associated with GrimAge at Y15 and Y20. Emphysema at Y25 was associated with GrimAge at Y15 and Y20. Conclusion: Pulmonary function was associated with GrimAge during early and mid-life; GrimAge partially mediated the association between pulmonary function and emphysema.

Associations of a Plant-centered Diet and Lung Function Decline across Early to Mid-Adulthood: The CARDIA Lung Study

Background

Lung function throughout adulthood predicts morbidity and mortality even among adults without chronic respiratory disease. Diet quality may represent a modifiable risk factor for lung function impairment later in life. We investigated associations between nutritionally-rich plant-centered diet and lung function decline across early and middle adulthood from the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

Methods

Diet was assessed at baseline and years 7 and 20 of follow-up using the validated CARDIA diet history questionnaire. Plant-centered diet quality was scored using the validated A Priori Diet Quality Score (APDQS), which weights food groups to measure adherence to a nutritionally-rich plant-centered diet 1 to 5 points for 20 beneficially rated foods and 5 to 1 points for 13 adversely rated foods. Scores were cumulatively averaged over follow-up and categorized into quintiles. The primary outcome was lung function decline, including forced expiratory volume in 1 second (FEV1) and functional vital capacity (FVC), measured at years 0, 2, 5, 10, 20, and 30. We estimated the association of APDQS with annual pulmonary function changes in a repeated measures regression model, adjusting for clinically relevant covariates.

Results

The study included 3,787 Black and White men and women aged 18-30 in 1985-86 and followed for 30 years. In multivariable repeated measures regression models, individuals in the lowest APDQS quintile (poorest diet) had declines in FEV1 that were 1.6 ml/year greater than individuals in the highest quintile (35.0 vs. 33.4 ml/year, ß±SE per 1 SD change APDQS 0.94 ± 0.36, p = 0.009). Additionally, declines in FVC were 2.4 ml/year greater in the lowest APDQS quintile than those in the highest quintile (37.0 vs 34.6 ml/year, ß±SE per 1 SD change APDQS 1.71 ± 0.46, p < 0.001). The association was not different between never and ever smokers (pint = 0.07 for FVC and 0.32 for FEV1). In sensitivity analyses where current asthma diagnosis and cardiorespiratory fitness were further adjusted, results remained similar.

Conclusions

In this 30-year longitudinal cohort study, long-term adherence to a nutritionally-rich plant-centered diet was associated with slower decline in lung function, highlighting diet quality as a potential treatable trait supporting long-term lung health.

Pulmonary Function Trajectories in People with HIV: Analysis of the Pittsburgh HIV Lung Cohort

Rationale: Human immunodeficiency virus (HIV) infection is associated with chronic lung disease and impaired pulmonary function; however, longitudinal pulmonary function phenotypes in HIV are undefined. Objectives: To identify pulmonary function trajectories, their determinants, and outcomes. Methods: We used data from participants with HIV in the Pittsburgh HIV Lung Cohort with three or more pulmonary function tests between 2007 and 2020. We analyzed post-bronchodilator forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC, and diffusing capacity of the lung for carbon monoxide (DlCO) using group-based trajectory modeling to identify subgroups of individuals whose measurements followed a similar pattern over time. We examined the association between participant characteristics and trajectories using multivariable logistic regression. In exploratory adjusted analyses restricted to individuals with available plasma cytokine data, we investigated the association between 18 individual standardized cytokine concentrations and trajectories. We compared mortality, dyspnea prevalence, respiratory health status, and 6-minute-walk distance between phenotypes. Results: A total of 265 participants contributed 1,606 pulmonary function measurements over a median follow-up of 8.1 years. We identified two trajectories each for FEV1 and FVC: "low baseline, slow decline" and "high baseline, rapid decline." There were three trajectory groups for FEV1/FVC: "rapid decline," "moderate decline," and "slow decline." Finally, we identified two trajectories for DlCO: "baseline low" and "baseline high." The low baseline, slow decline FEV1 and FVC, rapid decline, and moderate decline FEV1/FVC, and baseline low DlCO phenotypes were associated with increased dyspnea prevalence, worse respiratory health status, and decreased 6-minute-walk distance. The baseline low DlCO phenotype was also associated with worse mortality. Current smoking and pack-years of smoking were associated with the adverse FEV1, FEV1/FVC, and DlCO phenotypes. Detectable viremia was the only HIV marker associated with the adverse DlCO phenotype. C-reactive protein and endothelin-1 were associated with the adverse FEV1 and FVC phenotypes, and endothelin-1 trended toward an association with the adverse DlCO phenotype. Conclusions: We identified novel, distinct longitudinal pulmonary function phenotypes with significant differences in characteristics and outcomes. These findings highlight the importance of lung dysfunction over time in people with HIV and should be validated in additional cohorts.

Development of airflow limitation, dyspnoea, and both in the general population: the Nagahama study

Subjects with subclinical respiratory dysfunction who do not meet the chronic obstructive pulmonary disease (COPD) criteria have attracted attention with regard to early COPD intervention. Our aim was to longitudinally investigate the risks for the development of airflow limitation (AFL) and dyspnoea, the main characteristics of COPD, in a large-scale community-based general population study. The Nagahama study included 9789 inhabitants, and a follow-up evaluation was conducted after 5 years. AFL was diagnosed using a fixed ratio (forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) < 0.7). We enrolled normal subjects aged 40-75 years with no AFL, dyspnoea or prior diagnosis of asthma or COPD at baseline. In total, 5865 subjects were analysed, 310 subjects had subclinical respiratory dysfunction (FEV₁/FVC < the lower limit of normal; n = 57, and FEV₁ < 80% of the predicted value (preserved ratio impaired spirometry); n = 256). A total of 5086 subjects attended the follow-up assessment, and 449 and 1021 subjects developed AFL and dyspnoea, respectively. Of these, 100 subjects developed AFL with dyspnoea. Baseline subclinical respiratory dysfunction was independently and significantly associated with AFL with dyspnoea development within 5 years. Subjects with subclinical respiratory dysfunction are at risk of developing COPD-like features and require careful monitoring.

Influence of cardiovascular risk burden on pulmonary function trajectory: role of physical and social activities

The impact of cardiovascular risk burden on long-term trajectories of pulmonary function (PF) remains unclear. We examined the association of cardiovascular risk burden assessed by Framingham general cardiovascular risk score (FGCRS) with PF decline and explored whether cardiovascular diseases (CVD), physical and social activities play a role in the association. Within the Rush Memory and Aging Project, 1,442 participants (mean age:79.83) were followed up to 22 years. FGCRS at baseline was calculated and categorized into tertiles. Composite PF was measured annually based on peak expiratory flow, forced expiratory volume in one second, and forced vital capacity. We found that the highest FGCRS was associated with faster PF decline (β: -0.013, 95% CI: -0.023 to -0.003) compared with the lowest FGCRS. There were significant interactions between higher FGCRS and low level of physical/social activity (β: -0.014, 95% CI: -0.026 to -0.003)/(β: -0.020, 95% CI:-0.031 to -0.009) or CVD(β: -0.023, 95% CI:-0.034 to -0.011) compared to the low FGCRS with high level of physical/social activity or without CVD (P-interaction<0.05). Our results suggest that higher cardiovascular risk burden is associated with a faster PF decline, especially among people with CVD. High level of physical activity and social activity appears to mitigate this association.

Comparing Racial Differences in Emphysema Prevalence Among Adults With Normal Spirometry: A Secondary Data Analysis of the CARDIA Lung Study

BACKGROUND

Computed tomography (CT) imaging complements spirometry and may provide insight into racial disparities in respiratory health.

OBJECTIVE

To determine the difference in emphysema prevalence between Black and White adults with different measures of normal spirometry results.

DESIGN

Observational study using clinical data and spirometry from the CARDIA (Coronary Artery Risk Development in Young Adults) study obtained in 2015 to 2016 and CT scans done in 2010 to 2011.

SETTING

4 U.S. centers.

PARTICIPANTS

Population-based sample of Black and White adults.

MEASUREMENTS

Self-identified race and visually identified emphysema on CT in participants with different measures of "normal" spirometry results, calculated using standard race-specific and race-neutral reference equations.

RESULTS

A total of 2674 participants (485 Black men, 762 Black women, 659 White men, and 768 White women) had both a CT scan and spirometry available for analysis. Among participants with a race-specific FEV1 between 80% and 99% of predicted, 6.5% had emphysema. In this group, emphysema prevalence was 3.9-fold (95% CI, 2.1- to 7.1-fold; 15.5% vs. 4.0%) higher among Black men than White men and 1.9-fold (CI, 1.0- to 3.8-fold; 6.6% vs. 3.4%) higher among Black women than White women. Among participants with a race-specific FEV1 between 100% and 120% of predicted, 4.0% had emphysema. In this category, Black men had a 6.4-fold (CI, 2.2- to 18.7-fold; 13.9% vs. 2.2%) higher prevalence of emphysema than White men, whereas Black and White women had a similar prevalence of emphysema (2.6% and 2.0%, respectively). The use of race-neutral equations to identify participants with an FEV1 percent predicted between 80% and 120% attenuated racial differences in emphysema prevalence among men and eliminated racial differences among women.

LIMITATION

No CT scans were obtained during the most recent study visit (2015 to 2016) when spirometry was done.

CONCLUSION

Emphysema is often present before spirometry findings become abnormal, particularly among Black men. Reliance on spirometry alone to differentiate lung health from lung disease may result in the underrecognition of impaired respiratory health and exacerbate racial disparities.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Pathogenesis of chronic obstructive pulmonary disease: understanding the contributions of gene-environment interactions across the lifespan

The traditional view of chronic obstructive pulmonary disease (COPD) as a self-inflicted disease caused by tobacco smoking in genetically susceptible individuals has been challenged by recent research findings. COPD can instead be understood as the potential end result of the accumulation of gene-environment interactions encountered by an individual over the life course. Integration of a time axis in pathogenic models of COPD is necessary because the biological responses to and clinical consequences of different exposures might vary according to both the age of an individual at which a given gene-environment interaction occurs and the cumulative history of previous gene-environment interactions. Future research should aim to understand the effects of dynamic interactions between genes (G) and the environment (E) by integrating information from basic omics (eg, genomics, epigenomics, proteomics) and clinical omics (eg, phenomics, physiomics, radiomics) with exposures (the exposome) over time (T)-an approach that we refer to as GETomics. In the context of this approach, we argue that COPD should be viewed not as a single disease, but as a clinical syndrome characterised by a recognisable pattern of chronic symptoms and structural or functional impairments due to gene-environment interactions across the lifespan that influence normal lung development and ageing.

Genetics of chronic obstructive pulmonary disease: understanding the pathobiology and heterogeneity of a complex disorder

Chronic obstructive pulmonary disease (COPD) is a deadly and highly morbid disease. Susceptibility to and heterogeneity of COPD are incompletely explained by environmental factors such as cigarette smoking. Family-based and population-based studies have shown that a substantial proportion of COPD risk is related to genetic variation. Genetic association studies have identified hundreds of genetic variants that affect risk for COPD, decreased lung function, and other COPD-related traits. These genetic variants are associated with other pulmonary and non-pulmonary traits, demonstrate a genetic basis for at least part of COPD heterogeneity, have a substantial effect on COPD risk in aggregate, implicate early-life events in COPD pathogenesis, and often involve genes not previously suspected to have a role in COPD. Additional progress will require larger genetic studies with more ancestral diversity, improved profiling of rare variants, and better statistical methods. Through integration of genetic data with other omics data and comprehensive COPD phenotypes, as well as functional description of causal mechanisms for genetic risk variants, COPD genetics will continue to inform novel approaches to understanding the pathobiology of COPD and developing new strategies for management and treatment.

Neighborhood Socioeconomic Deprivation in Young Adulthood and Future Respiratory Health: The CARDIA Lung Study

PURPOSE

There are limited data on the relationship between neighborhood level factors and their association with lung health independent of individual socioeconomic status. We sought to determine whether baseline neighborhood level socioeconomic deprivation in young adults is associated with greater 20-year decline in lung function and higher risk of future lung disease, independent of baseline individual income, education, and smoking status.

METHODS

This multicenter population-based cohort study included 2689 participants in Coronary Artery Risk Development in Young Adults (CARDIA) for whom neighborhood deprivation was determined at year 10 (baseline for study) and who had complete lung function measurements at years 10 and 30. Baseline neighborhood deprivation was defined using 1990 Census blocks as a combination of 4 factors involving median household income, poverty level, and educational achievement. The outcomes were decline in lung function over 20 years (year 10 to 30) and odds of emphysema (year 25).

RESULTS

In multivariable regression models, greater baseline neighborhood deprivation was associated with greater decline in lung function (-2.34 mL/year excess annual decline in forced expiratory volume in 1 second (FEV₁) in the highest versus lowest deprivation quartile (P = .014)). Furthermore, baseline neighborhood deprivation was independently associated with greater odds of emphysema (odds ratio [OR] 2.99, 95% confidence interval [CI] 1.42-6.30).

CONCLUSIONS

Residence in neighborhoods with greater socioeconomic deprivation in young adulthood, independent of individual income and smoking, is associated with greater 20-year decline in forced expiratory volume in 1 second and higher risk of future emphysema.

The importance of central airway dilatation in patients with bronchiolitis obliterans

Background

Bronchiolitis obliterans (BO) is a clinical syndrome characterised by progressive small airway obstruction, causing significant morbidity and mortality. Central airway dilatation is one of its radiological characteristics, but little is known about the clinical and pathological associations between airway dilatation and BO.

Methods

This retrospective study consecutively included patients who underwent lung transplantation due to BO at Kyoto University Hospital from 2009 to 2019. Demographic and histopathological findings of the resected lungs were compared between patients with and without airway dilatation measured by chest computed tomography (CT) at registration for lung transplantation.

Results

Of a total of 38 included patients (median age, 30 years), 34 (89%) had a history of hematopoietic stem-cell transplantation, and 22 (58%) had airway dilatation based on CT. Patients with airway dilatation had a higher frequency of Pseudomonas aeruginosa isolation with greater residual volume than those without airway dilatation. Quantitative CT analysis revealed an increase in lung volume to predictive total lung capacity and a percentage of low attenuation volume <−950 HU at inspiration in association with the extent of airway dilatation. Airway dilatation on CT was associated with an increased number of bronchioles with concentric narrowing of the lumen and thickening of the subepithelium of the walls on histology.

Conclusions

In patients with BO, airway dilatation may reflect increased residual volume or air trapping and pathological extent of obstructive bronchioles, accompanied by a risk of Pseudomonas aeruginosa isolation. More attention should be paid to the development of airway dilatation in the management of BO.

In patients with bronchiolitis obliterans (BO), airway dilatation may reflect air trapping and the pathological extent of obstructive bronchioles. More attention should be paid to airway dilatation in the management of BO.https://bit.ly/3w7cRV6

Predictors of lung function trajectories in population-based studies: A systematic review

Despite the growing body of evidence on lung function trajectories over the life course and their risk factors, the literature has not been systematically synthesized. Publications related to lung function trajectories were identified from PubMed, EMBASE and CINAHL databases. Two authors independently identified publications for inclusion according to predefined selection criteria. Studies that modelled lung function trajectories and reported associated exposures were included. Meta-analyses could not be conducted due to heterogeneity in the exposures and methods used to model lung function trajectories. Nine publications were eligible for inclusion of which four used group-based trajectory modelling to model lung function trajectories, while five used latent profile analysis. Studies with repeated lung function measurements over the life course identified more trajectories than others. Only one study spanning from childhood to middle age reported catch-up trajectory. The following childhood risk factors for subnormal lung function trajectories were observed in at least across two studies: low birth weight, early wheezing, asthma, allergic sensitization, eczema, allergic rhinitis, lower respiratory tract infections, family history of asthma and second-hand smoke exposure. Adult active asthma and personal cigarette smoking were observed to be associated with accelerated decline lung trajectories. Our review identified 10 risk factors associated with the growth, catch-up, reduced plateau and decline trajectories of lung function. Intervention directed at childhood asthma and infections, and tobacco smoke exposure at all ages would help promote lung health and prevent subnormal lung function trajectories.

The Coronary Artery Risk Development In Young Adults (CARDIA) Study: JACC Focus Seminar 8/8

The CARDIA (Coronary Artery Risk Development in Young Adults) study began in 1985 to 1986 with enrollment of 5,115 Black or White men and women ages 18 to 30 years from 4 US communities. Over 35 years, CARDIA has contributed fundamentally to our understanding of the contemporary epidemiology and life course of cardiovascular health and disease, as well as pulmonary, renal, neurological, and other manifestations of aging. CARDIA has established associations between the neighborhood environment and the evolution of lifestyle behaviors with biological risk factors, subclinical disease, and early clinical events. CARDIA has also identified the nature and major determinants of Black-White differences in the development of cardiovascular risk. CARDIA will continue to be a unique resource for understanding determinants, mechanisms, and outcomes of cardiovascular health and disease across the life course, leveraging ongoing pan-omics work from genomics to metabolomics that will define mechanistic pathways involved in cardiometabolic aging.

Clinical Characteristics Associated With Lung Function Decline in Individuals With Adult-Diagnosed Cystic Fibrosis: Contemporary Analysis of the Canadian CF Registry

BACKGROUND

Individuals with cystic fibrosis (CF) diagnosed as adults represent a rare but growing subset of the CF population. Limited studies have described their lung function trajectories.

RESEARCH QUESTION

What is the overall trajectory of lung function and clinical characteristics associated with lung function decline in people who receive a diagnosis of CF as adults?

STUDY DESIGN AND METHODS

The Canadian CF Patient Registry (CCFR) was used to identify patients with CF who were ≥ 18 years of age at diagnosis and received a diagnosis between 2000 and 2017. Linear mixed-effects models were used to quantify the change in lung function over age and to examine clinical characteristics associated with lung function decline.

RESULTS

Lung function was stable in early adulthood, with a decline in middle adulthood (age 30-50 years) and a greater decline after 50 years of age. Individuals who receive a diagnosis at older ages (> 50 years: slope, -0.71%/y; 41-50 years: -0.68%/y; 31-40 years: -0.29%/y; 18-30 years: -0.28%/y) and those demonstrating pulmonary symptoms (slope, -0.41%/y) compared with no pulmonary symptoms at baseline were associated with faster rate of lung function decline.

INTERPRETATION

The lung function of who receive a diagnosis of CF as adults in the CCFR declines slowly compared with estimates from the overall adult CF population. Individuals with adult-diagnosed CF who are older and demonstrate pulmonary symptoms at diagnosis experience a faster rate of lung function decline and should be monitored more closely.

Diagnosis and Treatment of Early Chronic Obstructive Lung Disease (COPD)

Chronic obstructive lung disease (COPD) is responsible for substantial rates of mortality and economic burden, and is one of the most important public-health concerns. As the disease characteristics include irreversible airway obstruction and progressive lung function decline, there has been a great deal of interest in detection at the early stages of COPD during the “at risk” or undiagnosed preclinical stage to prevent the disease from progressing to the overt stage. Previous studies have used various definitions of early COPD, and the term mild COPD has also often been used. There has been a great deal of recent effort to establish a definition of early COPD, but comprehensive evaluation is still required, including identification of risk factors, various physiological and radiological tests, and clinical manifestations for diagnosis of early COPD, considering the heterogeneity of the disease. The treatment of early COPD should be considered from the perspective of prevention of disease progression and management of clinical deterioration. There has been a lack of studies on this topic as the definition of early COPD has been proposed only recently, and therefore further clinical studies are needed.

Artificial Intelligence in COPD: New Venues to Study a Complex Disease

Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous disease that can benefit from novel approaches to understanding its evolution and divergent trajectories. Artificial intelligence (AI) has revolutionized how we can use clinical, imaging, and molecular data to understand and model complex systems. AI has shown impressive results in areas related to automated clinical decision making, radiological interpretation and prognostication. The unique nature of COPD and the accessibility to well-phenotyped populations result in an ideal scenario for AI development. This review provides an introduction to AI and deep learning and presents some recent successes in applying AI in COPD. Finally, we will discuss some of the opportunities, challenges, and limitations for AI applications in the context of COPD.