Long-term prognosis of asthma, chronic obstructive pulmonary disease, and asthma-chronic obstructive pulmonary disease overlap in the Copenhagen City Heart study: a prospective population-based analysis

Distinct phenotype and risk factor analysis of persistent airflow limitation among asthmatic children: a case-control study

BACKGROUND

Persistent airflow limitation (PAL) in childhood asthma is associated with a poor prognosis. The aim of this study was to categorize asthmatic children with PAL into distinct phenotypes and investigate the risk factors associated with each phenotype.

METHODS

We conducted a case-control study with a total of 119 PAL patients and 120 non-PAL (NPAL) individuals. To classify the patients into appropriate clusters, unsupervised cluster analysis using K-means clustering was employed. The clusters were then compared to explore different PAL phenotypes. Univariate and multivariate logistic regression analyses were performed to identify risk factors for PAL and calculate odds ratios (ORs) with 95% confidence intervals (95%CIs).

RESULTS

K-means clustering divided patients into three clusters: Cluster 0 included 120 NPAL patients, Cluster 1 characterized by elevated blood neutrophils included 66 PAL patients, and Cluster 2 exhibited elevated blood eosinophils and FeNO levels, containing 53 PAL patients. Independent risk factors for PAL included older age in both Cluster 1 (9 ∼ 11y: OR 12.67, 95%CI 3.30-55.74; ≥ 11y: OR 5.42, 95%CI 1.26-25.69) and Cluster 2 (9 ∼ 11y: OR 7.25, 95%CI 1.70-33.35; ≥ 11y: OR 11.28, 95%CI 2.79-51.89), as well as pneumonia history, with an OR of 6.41(95%CI 1.34-33.41) in Cluster 1 and an OR of 7.92(95%CI 1.83-37.44) in Cluster 2. Furthermore, specific factors associated with Cluster 1 included BMI above 22 kg/ m 2 (OR 12.28, 95%CI 2.68-70.45), asthma duration exceeding three years (OR 4.77, 95%CI 1.60-15.94), and a blood neutrophil percentage between 0.4 and 0.5 (OR 4.13, 95%CI 1.17-16.6). In Cluster 2, independent risk factors included a blood eosinophil percentage greater than 0.07 (OR 4.36, 95%CI 1.16-19.73) and a high FeNO level (OR 3.94, 95%CI 1.35-11.97).

CONCLUSION

Our study identified two phenotypes of PAL in asthmatic children: non-eosinophilic and eosinophilic inflammation. Older age and a history of pneumonia were independent risk factors for both phenotypes. For non-eosinophilic inflammation PAL, specific contributing factors included higher BMI, long duration of asthma, and a blood neutrophil percentage between 0.4 and 0.5. Elevated FeNO levels and blood eosinophilic percentage were independently associated with eosinophilic inflammation PAL.

Susceptible Young Adults and Development of Chronic Obstructive Pulmonary Disease Later in Life

Rationale: Chronic obstructive pulmonary disease (COPD) has its origin in early life, and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) proposes a predisease state termed "pre-COPD." Objectives: We tested the hypothesis that susceptible young adults identified with chronic bronchitis and subtle lung function impairment will develop COPD later in life. Methods: We followed random individuals without COPD ages 20-50 years from two population-based cohorts from different smoking eras-the Copenhagen General Population Study from 2003 (N = 5,497) and the Copenhagen City Heart Study from 1976-1978 (N = 2,609)-for 10 and 25 years, for the development of COPD (FEV1/FVC <0.70) and COPD GOLD Stages 2-4 (additionally, FEV1 <80% predicted). Measurements and Main Results: After 10 years, 28% developed COPD and 13% developed COPD GOLD Stages 2-4 in individuals susceptible to COPD, compared with 8% and 1% in those without any susceptibility to COPD. Correspondingly, after 25 years, 22% versus 13% developed COPD and 20% versus 8% developed COPD GOLD Stages 2-4. More than half of incident COPD cases developed from a susceptible state. Compared with those without susceptibility to COPD, multivariable-adjusted odds ratios in those susceptible to COPD were 3.42 (95% confidence interval: 2.78-4.21) for COPD and 10.1 (6.77-15.2) for COPD GOLD Stages 2-4 after 10 years and were 1.54 (1.23-1.93) and 2.12 (1.64-2.73) after 25 years. The ability of a COPD risk score-consisting of the state of susceptibility to COPD with smoking and asthma as risk factors-to predict COPD later in life was high. Conclusions: Our study suggests the existence of a predisease state of COPD, which can be used for early identification of susceptible individuals at risk for COPD later in life.

Low smoking exposure and development and prognosis of COPD over four decades: a population-based cohort study

BACKGROUND

A diagnosis of COPD is mainly considered in individuals with >10 pack-years of smoking. We tested the hypothesis that low smoking exposure, below the critical threshold of 10 pack-years, increases risk of COPD and leads to poor prognosis.

METHODS

We followed non-obstructed adult smokers from the Copenhagen City Heart Study for COPD, defined as a forced expiratory volume in 1 s (FEV1)/forced vital capacity <0.70 and FEV1 <80% predicted, and for related clinical outcomes. First, we followed individuals for 5 years according to baseline smoking for risk of developing COPD, and thereafter for up to four decades for severe exacerbations and death.

RESULTS

In 6098 non-obstructed smokers, 1781 (29%) developed COPD after 5 years of follow-up: 23% of individuals with <10 pack-years of smoking at baseline, 26% of those with 10-19.9 pack-years, 30% of those with 20-39.9 pack-years and 39% of those with ≥40 pack-years. During four decades of follow-up, we recorded 620 exacerbations and 5573 deaths. Compared to individuals without COPD with <10 pack‑years of smoking, multivariable adjusted hazard ratios (HRs) for exacerbations were 1.94 (95% CI 1.36-2.76) in those without COPD and ≥10 pack-years, 2.83 (95% CI 1.72-4.66) in those with COPD and <10 pack-years, 4.34 (95% CI 2.93-6.43) in those with COPD and 10-19.9 pack-years, 4.39 (95% CI 2.98-6.46) in those with COPD and 20-39.9 pack-years and 4.98 (95% CI 3.11-7.97) in those with COPD and ≥40 pack-years. Corresponding HRs for all-cause mortality were 1.20 (95% CI 1.10-1.32), 1.31 (95% CI 1.13-1.53), 1.59 (95% CI 1.40-1.79), 1.81 (95% CI 1.62-2.03) and 1.81 (95% CI 1.55-2.10).

CONCLUSION

Low smoking exposure below the critical threshold of 10 pack-years increases risk of COPD in middle-aged adults within 5 years, and these individuals have increased risk of severe exacerbation and early death over four decades.

Mucus plugging on computed tomography and the sputum microbiome in patients with asthma, chronic obstructive pulmonary disease, and asthma-COPD overlap

BACKGROUND

Despite clinical implications, the pathogenesis of mucus plugging in asthma, chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap (ACO) remains unclear. We hypothesized that distinct airway microbiomes might affect mucus plugging differently among ACO, asthma, and COPD and among different extents of airway eosinophilic inflammation.

METHODS

The sputum microbiome, sputum cell differential count, and mucus plug score on computed tomography were cross-sectionally evaluated in patients with chronic airflow limitation.

RESULTS

Patients with ACO, asthma, or COPD were enrolled (n = 56, 10, and 25). Higher mucus plug scores were associated with a greater relative abundance of the phylum Proteobacteria (rho = 0.29) only in patients with ACO and a greater relative abundance of the phylum Actinobacteria (rho = 0.46) only in patients with COPD. In multivariable models including only patients with ACO, the presence of mucus plugs was associated with a greater relative abundance of the phylum Proteobacteria and the genus Haemophilus, independent of smoking status, airflow limitation, and emphysema severity. Moreover, the mucus score was associated with a greater relative abundance of the genus Streptococcus (rho = 0.46) in patients with a high sputum eosinophil count (n = 22) and with that of the genus Haemophilus (rho = 0.46) in those with a moderate sputum eosinophil count (n = 26).

CONCLUSIONS

The associations between mucus plugging and the microbiome in ACO differed from those in COPD and asthma. Greater relative abundances of the phylum Proteobacteria and genus Haemophilus may be involved in mucus plugging in patients with ACO and moderate airway eosinophilic inflammation.

Mortality of patients with COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is the third most common cause of death worldwide and 24% of the patients die within 5 years of diagnosis.

AREAS COVERED

The epidemiology of mortality and the interventions that reduce it are reviewed. The increasing global deaths reflect increases in population sizes, increasing life expectancy and reductions in other causes of death. Strategies to reduce mortality aim to prevent the development of COPD and improve the survival of individuals. Historic changes in mortality give insights: improvements in living conditions and nutrition, and later improvements in air quality led to a large fall in mortality in the early 20th century. The smoking epidemic temporarily reversed this trend.Older age, worse lung function and exacerbations are risk factors for death. Single inhaler triple therapy; smoking cessation; pulmonary rehabilitation; oxygen therapy; noninvasive ventilation; and surgery reduce mortality in selected patients.

EXPERT OPINION

The importance of addressing the global burden of mortality from COPD must be recognized. Steps must be taken to reduce it, by reducing exposure to risk factors, assessing individual patients' risk of death and using treatments that reduce the risk of death. Mortality rates are falling in countries that have adopted a comprehensive approach to COPD prevention and treatment.

Epidemiological characteristics of asthma-COPD overlap, its association with all-cause mortality, and the mediating role of depressive symptoms: evidence from NHANES 2005-2018

BACKGROUND

Asthma-COPD overlap (ACO) is a distinct and intricate respiratory condition that requires specific attention and management. The objective of this cohort study was to examine the epidemiological characteristics of ACO, explore the association between ACO and all-cause mortality, and investigate the potential mediating role of depressive symptoms in this association.

METHODS

This retrospective cohort study used data from the National Health and Nutrition Examination Survey (NHANES) 2005-2018 and National Death Index (NDI) 2019. A total of 22,745 participants were included: 705 with ACO, 2352 with asthma-only, 853 with COPD-only, and 18,835 without asthma or COPD. The non-ACO group (N = 22,040) referred to the individuals without ACO. Statistical tests were employed to assess differences in some characteristics between the ACO group and the other groups. Cox proportional hazards models were applied to evaluate the relationship between ACO and all-cause mortality, estimating hazard ratios (HR) with 95% confidence intervals. Mediation analysis was conducted to investigate the potential mediating effects of depressive symptoms on the association of ACO with all-cause mortality.

RESULTS

The prevalence of ACO was 3.10% in our study population. Compared to the non-ACO participants, the ACO participants exhibited significantly different characteristics, including higher age, a lower family income-to-poverty ratio, a higher body mass index, higher rates of comorbidities i.e., hypertension, diabetes, hyperlipidemia, cardiovascular disease, and cancer, poorer dietary habits, and a higher rate of depressive disorders. Compared to the participants without ACO, the participants with ACO exhibited a significant increase in all-cause mortality (HR = 1.908, 95%CI 1.578-1.307, p < 0.001). The proportions mediated by depressive symptoms for ACO -associated all-cause mortality were 8.13% (CI: 4.22%-14.00%, p < 0.001).

CONCLUSIONS

This study revealed a strong relationship between ACO and all-cause mortality and uncovered a potential psychological mechanism underlying this relationship. Our study indicates the possible necessity of offering comprehensive care to ACO patients, encompassing early detection, lifestyle guidance, and mental health support. Nevertheless, due to the limitations in the study design and the dataset, the results should be interpreted with caution.

Dupilumab sustains lung function improvements in patients with moderate-to-severe asthma

BACKGROUND

TRAVERSE (NCT02134028), a phase 3 open-label extension study, assessed dupilumab safety and efficacy in patients with asthma aged ≥12 years who completed a previous dupilumab asthma study. This analysis evaluated changes in multiple lung function parameters in patients with moderate-to-severe asthma with elevated type 2 biomarkers (baseline eosinophils ≥150 cells·μL-1 or fractional exhaled nitric oxide ≥25 ppb) who completed QUEST (parent study) and 2 years of dupilumab treatment in TRAVERSE.

METHODS

Endpoints analyzed included: pre-bronchodilator forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), forced expiratory flow (FEF25-75 %), and pre- and post-bronchodilator FEV1/FVC at parent study baseline (PSBL) at Weeks 0, 2, 48, and 96 in TRAVERSE, as well as pre- and post-bronchodilator FEV1 slopes in QUEST and TRAVERSE. Statistical analyses were descriptive.

RESULTS

Dupilumab improved pre-bronchodilator FEV1, FVC, and FEF25-75 % in QUEST; these improvements were sustained in TRAVERSE. In QUEST patients who received placebo, dupilumab initiation in TRAVERSE resulted in rapid lung function improvements. Mean (standard deviation) changes from PSBL at TRAVERSE Weeks 48 and 96 in pre-bronchodilator FEV1 were 0.52 (0.59) and 0.45 (0.49) L in the dupilumab/dupilumab group and 0.47 (0.42) and 0.44 L (0.45) in the placebo/dupilumab group, respectively. Similar trends were observed for FVC and FEF25-75 %. Dupilumab also improved FEV1 slopes in QUEST and TRAVERSE.

CONCLUSION

Dupilumab demonstrated sustained improvements across multiple spirometric lung function measurements for up to 3 years; patients who received placebo in QUEST experienced rapid lung function improvement upon initiation of dupilumab in TRAVERSE.

Level of Education Modifies Asthma Mortality in Norway and Sweden. The Nordic EpiLung Study

Background and Aim

The relationship between socioeconomic status (SES), asthma and mortality is complex and multifaceted, and it is not established if educational level modifies the association between asthma and mortality. The aim was to study the association between asthma and mortality in Sweden and Norway and to what extent educational level modifies this association.

Participants and Methods

Within the Nordic EpiLung Study, >56,000 individuals aged 30-69 years participated in population-based surveys on asthma and associated risk factors in Sweden and Norway during 2005-2007. Data on educational level and 10-year all-cause mortality were linked by national authorities. The fraction of mortality risk attributable to asthma was calculated, and Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for mortality related to asthma, stratified by educational level.

Results

In total, 5.5% of all deaths was attributed to asthma. When adjusted for potential confounders, the HR for mortality related to asthma was 1.71 (95% CI 1.52-1.93). Those with primary level of education had higher hazard of all-cause death related to asthma than those with tertiary level (HR 1.80, 95% CI 1.48-2.18, vs HR 1.39, 95% CI 0.99-1.95).

Conclusion

Asthma was associated with an overall 71% increased all-cause mortality and 5.5% of deaths can be attributed to asthma. Educational levels modified the risk of mortality associated with asthma, with the highest risk among those with primary education.

Type-2 inflammation and lung function decline in chronic airway disease in the general population

BACKGROUND

It is unclear if type-2 inflammation is associated with accelerated lung function decline in individuals with asthma and chronic obstructive pulmonary disease (COPD). We tested the hypothesis that type-2 inflammation indicated by elevated blood eosinophils (BE) and fraction of exhaled nitric oxide (FeNO) is associated with accelerated lung function decline in the general population.

METHODS

We included adults from the Copenhagen General Population Study with measurements of BE (N=15 605) and FeNO (N=2583) from a follow-up examination and assessed forced expiratory volume in 1 s (FEV1) decline in the preceding 10 years. Based on pre- and post-bronchodilator lung function, smoking history and asthma at follow-up examination, participants were assigned as not having airway disease, asthma with full reversibility (AR), asthma with persistent obstruction (APO), COPD, and not classifiable airflow limitation (NAL).

RESULTS

FEV1 decline in mL/year increased with 1.0 (95% CI 0.6 to 1.4, p<0.0001) per 100 cells/µL higher BE and with 3.2 (95% CI 2.0 to 4.5, p<0.0001) per 10 ppb higher FeNO. Adjusted FEV1 decline in mL/year was 18 (95% CI 17 to 20) in those with BE<300 cells/µL and FeNO<20 ppb, 22 (19-25) in BE≥300 cells/µL or FeNO≥20 ppb, and 27 (21-33) in those with BE≥300 cells/µL and FeNO≥20 ppb (p for trend<0.0001). Corresponding FEV1 declines were 24 (19-29), 33 (25-40) and 44 (31-56) in AR (0.002), 26 (14-37), 36 (12-60) and 56 (24-89) in APO (0.07), 32 (27-36), 31 (24-38) and 44 (24-65) in COPD (0.46), and 27 (21-33), 35 (26-45), and 37 (25-49) in NAL (0.10), respectively.

CONCLUSIONS

Type-2 inflammation indicated by elevated BE and FeNO is associated with accelerated FEV1 decline in individuals with chronic airway disease in the general population, and this association was most pronounced in an asthma-like phenotype.

Sociodemographic correlates with prevalence of comorbidities in patients with chronic obstructive pulmonary disease: a study from a Chinese National Survey

Background

An increase in the prevalence of comorbidities has been reported in patients with chronic obstructive pulmonary disease (COPD). However, contemporary estimates of the overall prevalence of the sociodemographic correlates of COPD comorbidities are scarce and inconsistent in China. This study aimed to investigate the prevalence of sociodemographic correlates of comorbidities in patients with COPD across China.

Methods

This was a cross-sectional study. We used data from the Enjoying Breathing Program between May 2020 and April 2022. Participants with COPD from 17 provinces (or equivalent) were included. Comorbidity clusters were stratified based on the number of comorbidities per person. Univariable and multivariable analyses were used to determine the sociodemographic associations of patients with COPD with specific clusters of comorbidities after adjusting for age, sex, and other prespecified covariates. Tetrachoric correlation analyses were performed to determine the associations between specific comorbidities.

Findings

A total of 3913 participants with COPD were included, of whom 1744 (44.7%) had at least one comorbidity; 25.4% had one comorbid disease, 12.9% had two, and 6.4% had three or more concurrent diseases. The most common comorbidities were hypertension (17.8%), asthma (9.9%), bronchiectasis (8.2%), diabetes (8.2%), and coronary artery disease (7.7%). In the logistic regression models adjusted for a broad set of factors, patients with COPD residing in the east region of China and having health insurance experienced a decreased likelihood of comorbidities (from OR = 0.70 [95% confidence interval [CI], 0.53-0.93] to OR = 0.50 [95% CI, 0.25-0.99]). However, patients over 80 years had increased risk (OR 1.43 [95% CI 1.01-2.03]), as did those in all Modified Medical Research Council (mMRC) grade categories (grade 1: OR = 1.30 [95% CI, 1.02-1.65]; grade 2: OR = 1.39 [95% CI, 1.07-1.8]; grade 3: OR = 1.67 [95% CI, 1.23-2.26]; and grade 4: OR = 1.81 [95% CI, 1.00-3.28]) and in Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2 classification (OR = 1.30 [95% CI, 1.03-1.65]) relative to their respective references. The associations observed in these subgroups were consistent regardless of the number of comorbidities per person. Tetrachoric correlations demonstrated negative associations in pairwise comparisons of the top five comorbidities, ranging from -0.03 to -0.31 (p < 0.001 in all groups).

Interpretation

In China, comorbidities are highly prevalent among patients with COPD, with older age, higher mMRC grade, and lung function decline being the major risk factors. Studies with larger sample sizes are required to elucidate the complex mechanisms underlying COPD comorbidities.

Funding

This study was funded by CAMS Innovation Fund for Medical Sciences (CIFMS) (2021-I2M-1-049 and 2022-I2M-C&T-B-107).

Exacerbation rates in Japanese patients with obstructive lung disease: A subanalysis of the prospective, observational NOVELTY study

BACKGROUND

Although clinical trials including asthma and COPD patients have revealed much about exacerbation frequencies, most studies are limited in that they recruited patients only with a clear diagnosis of one disease or the other, based on conventional diagnostic criteria, which may exclude many real-world patients with mixed symptoms.

METHODS

NOVELTY is a global prospective observational study of patients with asthma and/or COPD from real-world practice. In this subanalysis, we compared patient characteristics of obstructive pulmonary diseases between the Japanese population (n = 820) and the overall population excluding Japanese patients (n = 10,406).

RESULTS

The Japanese population had fewer exacerbations than the overall population across most of the physician-assessed disease severities and all diagnoses. The difference in exacerbation frequencies was more prominent in patients with COPD and asthma + COPD. The Japanese population was older, had higher former smoking rates, lower BMI, fewer respiratory symptoms, and better health-related quality of life compared with the overall population across all diagnoses.

CONCLUSIONS

We clarified differences in patient characteristics among patients with asthma and/or COPD in Japan compared with non-Japanese patients. Importantly, we found that Japanese patients with asthma and/or COPD had significantly fewer exacerbations compared with patients overall. The results from our study may contribute to the development of precision medicine and guidelines specific to Japan.

Sex-Specific Genetic Determinants of Asthma-COPD Phenotype and COPD in Middle-Aged and Older Canadian Adults: An Analysis of CLSA Data

The etiology of sex differences in the risk of asthma-COPD phenotype and COPD is still not completely understood. Genetic and environmental risk factors are commonly believed to play an important role. This study aims to identify sex-specific genetic markers associated with asthma-COPD phenotype and COPD using the Canadian Longitudinal Study on Aging (CLSA) Baseline Comprehensive and Genomic data. There were a total of 1,415 COPD cases. Out of them, 504 asthma-COPD phenotype cases were identified. 20,524 participants without a diagnosis of asthma and COPD served as controls. We performed genome-wide SNP-by-sex interaction analysis. SNPs with an interaction p-value < 10^-5 were included in a sex-stratified multivariable logistic regression for asthma-COPD phenotype and COPD outcomes. 18 and 28 SNPs had a significant interaction term p-value < 10^-5 with sex in the regression analyses of asthma-COPD phenotype and COPD outcomes, respectively. Sex-stratified multivariable analysis of asthma-COPD phenotype showed that 7 SNPs in/near SMYD3, FHIT, ZNF608, RIMBP2, ZNF133, BPIFB1, and S100B loci were significant in males. Sex-stratified multivariable analysis of COPD showed that 8 SNPs in/near MAGI1, COX18, OSTC, ELOVL5, C7orf72 FGF14, and NKAIN4 were significant in males, and 4 SNPs in/near genes CAMTA1, SATB2, PDE10A, and LINC00908 were significant in females. An SNP in the ZPBP gene was associated with COPD in both males and females. Identification of sex-specific loci associated with asthma-COPD phenotype and COPD may offer valuable evidence toward a better understanding of the sex-specific differences in the pathophysiology of the diseases.

Dupilumab sustains efficacy in patients with moderate-to-severe type 2 asthma regardless of inhaled corticosteroids dose

BACKGROUND

Dupilumab, a human monoclonal antibody, blocks the shared receptor component for interleukins-4/13, key and central drivers of type 2 inflammation. The TRAVERSE (NCT02134028) open-label extension study demonstrated the long-term safety and efficacy of dupilumab in patients ≥12 years who completed a previous dupilumab asthma study. The safety profile was consistent with that observed in the parent studies. Here, we assess whether dupilumab sustains long-term efficacy in patients regardless of inhaled corticosteroid (ICS) dose at parent study baseline (PSBL).

METHODS

Patients from phase 2b (NCT01854047) or phase 3 (QUEST; NCT02414854) studies receiving high- or medium-dose ICS at PSBL and enrolled in TRAVERSE were included. We analyzed unadjusted annualized severe exacerbation rates, change from PSBL in pre-bronchodilator (BD) forced expiratory volume in 1 second (FEV1 ), 5-item asthma control questionnaire, and type 2 biomarkers in patients with type 2 asthma at baseline (blood eosinophils ≥150 cells/μL or fractional exhaled nitric oxide [FeNO] ≥25 ppb), and subgroups defined by baseline blood eosinophils or FeNO.

RESULTS

Of patients with type 2 asthma (n = 1666), 891 (53.5%) were receiving high-dose ICS at PSBL. In this subgroup, unadjusted exacerbation rates for dupilumab versus placebo were 0.517 versus 1.883 (phase 2b) and 0.571 versus 1.300 (QUEST) over the parent study (52 weeks) and remained low throughout TRAVERSE (0.313-0.494). Improvements in pre-BD FEV1 were sustained throughout TRAVERSE. Similar clinical efficacy was observed among patients receiving medium-dose ICS at PSBL and biomarker subgroups.

CONCLUSIONS

Dupilumab showed sustained efficacy for up to 3 years in patients with uncontrolled, moderate-to-severe type 2 asthma on high- or medium-dose ICS.

Underdiagnosis and misclassification of COPD in Sweden - A Nordic Epilung study

INTRODUCTION

The prevalence of COPD tends to level off in populations with decreasing prevalence of smoking but the extent of underdiagnosis in such populations needs further investigation.

AIM

To investigate underdiagnosis and misclassification of COPD with a focus on socio-economy, lifestyle determinants and healthcare utilization.

METHOD

The 1839 participants were selected from two ongoing large-scale epidemiological research programs: The Obstructive Lung Disease in Northern Sweden Studies and the West Sweden Asthma Study. COPDGOLD was defined according to the fixed post-bronchodilator spirometric criteria FEV1/FVC<0.70 in combination with respiratory symptoms.

RESULTS

Among the 128 participants who fulfilled the criteria for COPDGOLD, the underdiagnosis was 83.6% (n = 107) of which 57.9% were men. The undiagnosed participants were younger, had higher FEV1% of predicted and less frequently a family history of bronchitis. One in four of the undiagnosed had utilized healthcare and had more frequently utilized healthcare due to a burden of respiratory symptoms than the general population without COPD. Underdiagnosis was not related to educational level. Misclassification of COPD was characterized by being a woman with low education, ever smoker, having respiratory symptoms and having a previous asthma diagnosis.

CONCLUSION

In the high income country Sweden, the underdiagnosis of COPD was highly prevalent. Reduced underdiagnosis can contribute to risk factor modification, medical treatment and self-management strategies in early stages of the disease, which may prevent disease progression and improve the quality of life among those affected. Therefore, there is a need to increase the use of spirometry in primary care to improve the diagnostic accuracy.

Toward a Predict and Prevent Approach in Obstructive Airway Diseases

Asthma and chronic obstructive pulmonary disease are currently diagnosed and treated after the demonstration of variable airflow limitation and symptoms. Under this framework, undiagnosed and unchecked airway inflammation is associated with recurrent acute attacks, airway remodeling, airflow limitation, adverse effects of corticosteroids, and impaired quality of life, ultimately leading to the collection of side effects termed "people remodeling." This one-size-fits-all damage control approach aims to control symptoms and treat exacerbations rather than modify the underlying disease process. The advent of highly effective therapies targeting proximal drivers of airway inflammation calls for a paradigm shift; upstream-acting therapies offer potential to alter the disease course and achieve clinical remission. We propose moving away from downstream firefighting and toward a "predict and prevent" model, measuring inflammation and providing anti-inflammatory therapy early, without waiting for further clinical deterioration. Much in the same way that high blood pressure and cholesterol are used to predict and prevent heart attacks, in asthma, elevated blood eosinophils and/or exhaled nitric oxide can be used to predict and prevent asthma attacks. We also advocate moving research further upstream by identifying patients with subclinical airway inflammation or disease who may be at risk of progressing to airflow limitation and associated morbidities and intervening early to prevent them. In summary, we call for a predict and prevent approach in obstructive airway disease.

Association between tobacco product use and asthma among US adults from the Population Assessment of Tobacco and Health (PATH) Study waves 2-4

BACKGROUND

Research on cigarettes and adult asthma offers mixed findings, perhaps due to overlap with chronic obstructive pulmonary disease (COPD) and inadequate adjustment for other smoke exposures. Associations between other tobacco products, including e-cigarettes, and asthma are also understudied.

RESEARCH QUESTION

Using Population Assessment of Tobacco and Health Study waves 2-4 (2014/2015-2016/2017) data, we assessed the relation between tobacco product use and asthma in persons unlikely to have COPD.

STUDY DESIGN AND METHODS

Prospective study of 10 267 adults aged 18-39 years without COPD diagnoses. Past-month tobacco use at wave 2 was modelled first as combustible versus non-combustible use and second as specific product categories (former, cigarettes, e-cigarettes, cigars, hookah, smokeless tobacco). Outcomes included lifetime asthma prevalence at wave 2, incidence (waves 3 and 4) and Asthma Control Test score (lower=worse). Multivariable regressions adjusted for predictors of asthma, including other smoke exposures: cigarette pack-years, secondhand smoke and marijuana use. Sensitivity analyses examined findings when persons >39 years and those with both COPD and asthma were added, and when smoke exposure adjustments were removed.

RESULTS

No product, including cigarettes and e-cigarettes, was associated with prevalence or incidence of asthma. Among people with asthma at wave 2, combustible tobacco (beta=-0.86, 95% CI (-1.32 to -0.39)) and cigarettes (beta=-1.14, 95% CI (-1.66 to -0.62)) were associated with worse asthma control. No tobacco product was associated with asthma control over time. In sensitivity analyses, tobacco use became associated with incident asthma as adults >39 years and those with asthma+COPD were added, and as adjustments for other smoke exposures were omitted.

INTERPRETATION

Although cigarette use was associated with worse asthma control, there were no longitudinal associations between combustible tobacco or e-cigarette use and new onset or worsening asthma in these preliminary analyses. Research on tobacco and asthma should exclude COPD and adjust for smoking history and other smoke exposures.

Real-World Evidence on the Diagnostic and Clinical Characteristics of Asthma in Japanese Patients with COPD: The ACO Japan Cohort Study

Introduction

The ACO Japan Cohort Study, a multicenter observational study, investigated the proportion of patients with chronic obstructive pulmonary disease (COPD) who met the Japanese Respiratory Society (JRS) asthma-COPD overlap (ACO) diagnostic criteria, characteristics of ACO and non-ACO patients, and the patient transitions between ACO/non-ACO diagnosis over 2 years.

Patients and Methods

Patients with COPD were consecutively enrolled between June and December 2018 and followed up continuously for 2 years. All participating study sites were medical institutions where respiratory specialists routinely conducted medical examinations/tests required for ACO diagnosis.

Results

Among 708 patients with COPD, 101 (14.3%), 118 (16.7%), and 125 (17.7%) were diagnosed with ACO at registration, 1 year, and 2 years, respectively. In total, 22.6% of patients lacked the data necessary for ACO diagnosis throughout the 2 years. Among patients who had the necessary data for ACO diagnosis, 24.7% were diagnosed with ACO at 2 years. More ACO patients had moderate or severe exacerbations in the past year than non-ACO patients at registration (15.8% vs 6.3%, p = 0.049) and 1 year (19.4% vs 7.6%, p = 0.025). ACO patients had a greater decrease in mean forced expiratory volume in one second over 2 years than non-ACO patients (-92.0 vs 43.4 mL). Among patients diagnosed with ACO at registration, 21.4% transitioned to non-ACO after 1 year. Conversely, almost all non-ACO patients at registration remained non-ACO after 1 year.

Conclusion

COPD patients with ACO determined by the JRS criteria had a high risk of exacerbations and a rapid decline in respiratory function, indicating that the JRS criteria for ACO are useful for identifying high-risk COPD patients. Testing necessary for ACO diagnosis is insufficiently performed even in real-world clinical practice of COPD specialists.

Heterogeneity of asthma-chronic obstructive pulmonary disease (COPD) overlap from a cohort of patients with severe asthma and COPD

BACKGROUND

A considerable proportion of patients have features of both asthma and chronic obstructive pulmonary disease (COPD) simultaneously, called asthma-COPD overlap (ACO).

OBJECTIVES

The aim of this study was to identify heterogeneity of ACO from a cohort of patients with severe asthma and COPD using the same diagnostic criteria.

DESIGN

We used the International Severe Asthma Registry (ISAR) and the Korean COPD Subgroup Study (KOCOSS) to evaluate clinical characteristics of ACO from each cohort.

METHODS

We classified subjects into four groups: (1) pure severe asthma, (2) ACO from the severe asthma cohort, (3) ACO from the COPD cohort, and (4) pure COPD. ACO was defined by satisfying extreme bronchodilator response (BDR) >15% and 400 ml and/or blood eosinophil count ⩾300 /µL in patients aged 40 years or older and post-BD forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratio <0.7.

RESULTS

The ACO group had 25 (23%) of 111 in the ISAR cohort and 403 (23%) of 1781 in the KOCOSS cohort. The ACO from the COPD cohort was older with more males and more smokers, but had similar degree of airflow limitation compared with the ACO from the severe asthma cohort. ICS-containing inhaler treatment was prescribed for all severe asthma subjects, but only for 43.9% of ACO subjects from the COPD cohort. Compared with patients having pure severe asthma, the risk for exacerbation was comparable in ACO either from severe asthma or COPD cohort [adjusted odds ratio (aOR): 1.54, 95% CI: 0.22-10.95 or aOR: 2.15, 95% CI: 0.59-7.85].

CONCLUSION

The prevalence of ACO was similar in severe asthma and COPD cohorts applying identical diagnostic criteria. ACO from the severe asthma cohort was similar to ACO from the COPD cohort in terms of lung function and exacerbation risk.

Mortality Associated With Occupational Exposure in Helsinki, Finland-A 24-Year Follow-up

OBJECTIVES

Our objective was to study mortality related to different obstructive lung diseases, occupational exposure, and their potential joint effect in a large, randomized population-based cohort.

METHODS

We divided the participants based on the answers to asthma and chronic obstructive pulmonary disease (COPD) diagnoses and occupational exposure and used a combined effects model and compared the results to no asthma or COPD with no occupational exposure.

RESULTS

High exposure had a hazards ratio (HR) of 1.34 (1.11-1.62) and asthma and COPD coexistence of 1.58 (1.10-2.27). The combined effects of intermediate exposure and coexistence had an HR of 2.20 (1.18-4.09), high exposure with coexistence of 1.94 (1.10-3.42) for overall mortality, and sub-HR for respiratory-related mortality of 3.21 (1.87-5.50).

CONCLUSIONS

High occupational exposure increased overall but not respiratory-related mortality hazards, while coexisting asthma and COPD overall and respiratory-related hazards of mortality.

Greek Guidelines for the Management of COPD, a Proposal of a Holistic Approach Based on the needs of the Greek Community

Despite that COPD remains one of the most common respiratory diseases worldwide, it can be managed effectively with certain treatments and, more importantly, be prevented by the early implementation of various measures. The pathology and pathophysiology of this disease continue to be studied, with new pharmacological and invasive therapies emerging. In this consensus paper, the Working Group of the Hellenic Thoracic Society aimed to consolidate the up-to-date information and new advances in the treatment of COPD. Local and international data on its prevalence are presented, with revised strategies on the diagnostic approach and the evaluation of risk assessment and disease severity classification. Emphasis is placed on the management and therapy of patients with COPD, covering both common principles, specialized modalities, and algorithms to distinguish between home care and the need for hospitalization. Although pharmacological treatment is commonly recognized in COPD, an integrative approach of pulmonary rehabilitation, physical activity, patient education, and self-assessment should be encountered for a comprehensive treatment, prevention of exacerbations, and increased quality of life in patients.

Does the asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) exist? A narrative review from epidemiology and practice

Asthma and chronic obstructive pulmonary disease (COPD) have traditionally been approached as separate entities that must be researched and treated separately. There is growing recognition, however, that a substantial proportion of patients with obstructive lung disease have characteristics of both asthma and COPD (termed the asthma-COPD overlap syndrome (ACOS)). Lung disease experts have difficulty defining ACOS, and many still resist accepting the possibility that asthma and COPD may be linked. It is likely that practicing clinicians may be equally confused about how to identify and treat ACOS. This narrative review aims to clarify concepts of ACOS definition, argues that the best way to understand ACOS is to view the chronic lung disease process longitudinally rather than cross-sectionally, and presents evidence that ACOS can be the end result of the natural history of severe asthma. The review also points out the serious gaps in knowledge regarding therapy for ACOS and presents emerging data supporting the intracellular respiratory pathogen Chlamydia pneumoniae as a possible common etiologic agent in severe asthma and ACOS.

Functional Predictors Discriminating Asthma-COPD Overlap (ACO) from Chronic Obstructive Pulmonary Disease (COPD)

Background

A significant proportion of patients with obstructive lung disease have clinical and functional features of both asthma and chronic obstructive pulmonary disease (COPD), referred to as the asthma-COPD overlap (ACO). The distinction of these phenotypes, however, is not yet well-established due to the lack of defining clinical and/or functional criteria. The aim of our investigations was to assess the discriminating power of various lung function parameters on the assessment of ACO.

Methods

From databases of 4 pulmonary centers, a total of 540 patients (231 males, 309 females), including 372 patients with asthma, 77 patients with ACO and 91 patients with COPD, were retrospectively collected, and gradients among combinations of explanatory variables of spirometric (FEV1, FEV1/FVC, FEF25-75), plethysmographic (sReff, sGeff, the aerodynamic work of breathing at rest; sWOB), static lung volumes, including trapped gases and measurements of the carbon monoxide transfer (DLCO, KCO) were explored using multiple factor analysis (MFA). The discriminating power of lung function parameters with respect to ACO was assessed using linear discriminant analysis (LDA).

Results

LDA revealed that parameters of airway dynamics (sWOB, sReff, sGeff) combined with parameters of static lung volumes such as functional residual capacity (FRCpleth) and trapped gas at FRC (VTG FRC) are valuable and potentially important tools discriminating between asthma, ACO and COPD. Moreover, sWOB significantly contributes to the diagnosis of obstructive airway diseases, independent from the state of pulmonary hyperinflation, whilst the diffusion capacity for carbon monoxide (DLCO) significantly differentiates between the 3 diagnostic classes.

Conclusion

The complexity of COPD with its components of interaction and their heterogeneity, especially in discrimination from ACO, may well be differentiated if patients are explored by a whole set of target parameters evaluating, interactionally, flow limitation, airway dynamics, pulmonary hyperinflation, small airways dysfunction and gas exchange disturbances assessing specific functional deficits.

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

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

Epidemiology of Asthma-Chronic Obstructive Pulmonary Disease Overlap

Asthma COPD Overlap has consistently reported to be associated with an increase burden of disease but the impact on lung function decline and mortality varies by study. The prevalence increases with age but the relationship with gender also varies with the study population. The variability in the prevalence and clinical characteristics of ACO is linked to differences in how chronic obstructive pulmonary disease (COPD) and asthma are defined, including diagnostic criteria (spirometry-based vs. clinical or symptom-based diagnoses vs. claims data), the population studied, the geographic region and environment and a consensus approach to the diagnosis of ACO is needed to allow meaningful and consistent epidemiologic information to be generated about this condition.

Defining Asthma-Chronic Obstructive Pulmonary Disease Overlap

Much interest has been given to the asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) in the past 2 decades, but the condition is still ill-defined. There is general agreement that a patient with longstanding asthma who develops fixed airflow obstruction after years of smoking has ACO although defining asthma in the face of COPD can be challenging. Many features of asthma are also found in patients with COPD without indicating an overlap and no consensus exists on which characteristics should be included in the definition of ACO. Nevertheless, some guidance has been issued to help clinicians and researchers to make a diagnosis of ACO and these will be reviewed here.

Long-term outcome of chronic obstructive pulmonary disease: A review

Chronic obstructive pulmonary disease (COPD) is a chronic airway inflammation characterized by fixed airflow limitation and chronic respiratory symptoms, such as cough, sputum, and dyspnea. COPD is a progressive disease characterized by a decline in lung function. During the natural course of the disease, acute deterioration of symptoms leading to hospital visits can occur and influence further disease progression and subsequent exacerbation. Moreover, COPD is not only restricted to pulmonary manifestations but can present with other systemic diseases as comorbidities or systemic manifestations, including lung cancer, cardiovascular disease, pulmonary hypertension, sarcopenia, and metabolic abnormalities. These pulmonary and extrapulmonary conditions lead to the aggravation of dyspnea, physical inactivity, decreased exercise capacity, functional decline, reduced quality of life, and increased mortality. In addition, pneumonia, which is attributed to both COPD itself and an adverse effect of treatment (especially the use of inhaled and/or systemic steroids), can occur and lead to further deterioration in the prognosis of COPD. This review summarizes the long-term outcomes of patients with COPD. In addition, recent studies on the prediction of adverse outcomes are summarized in the last part of the review.

Plasma immunoglobulin E and risk of exacerbation and mortality in chronic obstructive pulmonary disease: A contemporary population-based cohort

BACKGROUND

Novel biomarkers and targeted treatments are needed for patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVE

To test the hypothesis that high plasma immunoglobulin (Ig)E concentrations associate with increased risk of exacerbation and mortality in individuals with COPD in the general population.

METHODS

Among 46,598 adults in the Copenhagen General Population Study, we included 1559 with COPD, defined as forced expiratory volume in 1 second/forced vital capacity < 0.70 and forced expiratory volume in 1 second < 80% predicted in individuals aged ≥ 40 years with chronic respiratory symptoms and smoking exposure ≥ 10 pack-years, and without asthma. We assessed risk of future severe exacerbation and all-cause mortality according to baseline plasma IgE ≥ 76 IU/mL, a clinical cutoff for omalizumab treatment in severe asthma.

RESULTS

During 14 years of follow-up (median, 6.9; interquartile range, 3.4), we recorded 224 severe exacerbations and 434 deaths in 1559 individuals with COPD. Individuals with COPD with IgE ≥ 76 IU/mL vs those with < 76 IU/mL had a multivariable adjusted hazard ratio (HR) of 1.43 (95% confidence interval, 1.07-1.89) for severe exacerbation and 1.30 (1.05-1.62) for all-cause mortality. Compared with individuals with IgE < 76 IU/mL and blood eosinophils < 300 cells/µL, the multivariable adjusted HR for severe exacerbation was 1.12 (0.76-1.67) for those with IgE < 76 IU/mL and blood eosinophils ≥ 300 cells/µL, 1.62 (1.17-2.24) for IgE ≥ 76 IU/mL and blood eosinophils < 300 cells/µL, and 1.06 (0.63-1.77) for those with IgE ≥ 76 IU/mL and blood eosinophils ≥ 300 cells/µL. Corresponding HRs for all-cause mortality were 1.27 (0.99-1.63), 1.47 (1.14-1.88), and 1.17 (0.83-1.64), respectively.

CONCLUSION

High plasma IgE was associated with an increased risk of severe exacerbation and all-cause mortality in individuals with COPD in the general population, independent of blood eosinophils.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Characterization of Asthma by Age of Onset: A Multi-Database Cohort Study

BACKGROUND

Asthma can occur at any age but the differences in patient characteristics between childhood-, adult-, and late-onset asthma are not well understood.

OBJECTIVE

To investigate differences in patients' characteristics by age at asthma onset.

METHODS

From 5 European electronic databases, we created a cohort encompassing adult patients with doctor-diagnosed asthma in 2008 to 2013. Patients were categorized based on their age at asthma onset: childhood-onset (age at onset < 18 y), adult-onset (age at onset 18-40 y), and late-onset asthma (age at onset ≥ 40 y). Comorbidities were assessed at study entry. For each characteristic and comorbidity, odds ratios and age- and sex-adjusted odds ratios (OR_adj) comparing asthma-onset categories were estimated per database and combined in a meta-analysis using a random effect model.

RESULTS

In total, 586,436 adult asthma patients were included, 81,691 had childhood-onset, 218,184 adult-onset, and 286,561 late-onset asthma. Overall, 7.3% had severe asthma. Subjects with adult-onset compared with childhood-asthma had higher risks for overweight/obesity (OR_adj 1.4; 95% CI 1.1-1.8) and lower risks for atopic disorders (OR_adj 0.8; 95% CI 0.7-0.95). Patients with late-onset compared with adult-onset asthma had higher risks for nasal polyposis (OR_adj 1.8; 95% CI 1.2-2.6), overweight/obesity (OR_adj 1.3; 95% CI 1.2-1.4), gastroesophageal reflux disease (OR_adj 1.4; 95% CI 1.2-1.7), and diabetes (OR_adj 2.3; 95% CI 1.8-2.9). A significant association between late-onset asthma and uncontrolled asthma was observed (OR_adj 2.8; 95% CI 1.7-4.5).

CONCLUSIONS

This international study demonstrates clear differences in comorbidities between childhood-, adult-, and late-onset asthma phenotypes in adults. Furthermore, patients with late-onset asthma had more frequent uncontrolled asthma.

Type 2 inflammation in asthma and other airway diseases

Chronic inflammatory airway diseases, including asthma, chronic rhinosinusitis, eosinophilic COPD and allergic rhinitis are a global health concern. Despite the coexistence of these diseases and their common pathophysiology, they are often managed independently, resulting in poor asthma control, continued symptoms and poor quality of life. Understanding disease pathophysiology is important for best treatment practice, reduced disease burden and improved patient outcomes. The pathophysiology of type 2 inflammation is driven by both the innate immune system triggered by pollutants, viral or fungal infections involving type 2 innate lymphoid cells (ILC2) and the adaptive immune system, triggered by contact with an allergen involving type 2 T-helper (Th2) cells. Both ILC2 and Th2 cells produce the type-2 cytokines (interleukin (IL)-4, IL-5 and IL-13), each with several roles in the inflammation cascade. IL-4 and IL-13 cause B-cell class switching and IgE production, release of pro-inflammatory mediators, barrier disruption and tissue remodelling. In addition, IL-13 causes goblet-cell hyperplasia and mucus production. All three interleukins are involved in trafficking eosinophils to tissues, producing clinical symptoms characteristic of chronic inflammatory airway diseases. Asthma is a heterogenous disease; therefore, identification of biomarkers and early targeted treatment is critical for patients inadequately managed by inhaled corticosteroids and long-acting β-agonists alone. The Global Initiative for Asthma guidelines recommend add-on biological (anti IgE, IL-5/5R, IL-4R) treatments for those not responding to standard of care. Targeted therapies, including omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab and tezepelumab, were developed on current understanding of the pathophysiology of type 2 inflammation. These therapies offer hope for improved management of type 2 inflammatory airway diseases.

Magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic and progressive disease, often punctuated by recurrent flare-ups or exacerbations. Magnesium sulfate, having a bronchodilatory effect, may have a potential role as an adjunct treatment in COPD exacerbations. However, comprehensive evidence of its effects is required to facilitate clinical decision-making.

OBJECTIVES

To assess the effects of magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease in adults.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization (WHO) trials portal, EU Clinical Trials Register and Iranian Registry of Clinical Trials. We also searched the proceedings of major respiratory conferences and reference lists of included studies up to 2 August 2021.

SELECTION CRITERIA

We included single- or double-blind parallel-group randomised controlled trials (RCTs) assessing magnesium sulfate in adults with COPD exacerbations. We excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias. The primary outcomes were: hospital admissions (from the emergency room); need for non-invasive ventilation (NIV), assisted ventilation or admission to intensive-care unit (ICU); and serious adverse events. Secondary outcomes were: length of hospital stay, mortality, adverse events, dyspnoea score, lung function and blood gas measurements. We assessed confidence in the evidence using GRADE methodology. For missing data, we contacted the study investigators.

MAIN RESULTS

We identified 11 RCTs (10 double-blind and 1 single-blind) with a total 762 participants. The mean age of participants ranged from 62 to 76 years. Trials were single- or two-centre trials conducted in Iran, New Zealand, Nepal, Turkey, the UK, Tunisia and the USA between 2004 and 2018. We judged studies to be at low or unclear risk of bias for most of the domains. Three studies were at high risk for blinding and other biases.  Intravenous magnesium sulfate versus placebo Seven studies (24 to 77 participants) were included. Fewer people may require hospital admission with magnesium infusion compared to placebo (odds ratio (OR) 0.45, 95% CI 0.23 to 0.88; number needed to treat for an additional beneficial outcome (NNTB) = 7; 3 studies, 170 participants; low-certainty evidence). Intravenous magnesium may result in little to no difference in the requirement for non-invasive ventilation (OR 0.74, 95% CI 0.31 to 1.75; very low-certainty evidence). There were no reported cases of endotracheal intubation (2 studies, 107 participants) or serious adverse events (1 study, 77 participants) in either group. Included studies did not report intensive care unit (ICU) admission or deaths. Magnesium infusion may reduce the length of hospital stay by a mean difference (MD) of 2.7 days (95% CI 4.73 days to 0.66 days; 2 studies, 54 participants; low-certainty evidence) and improve dyspnoea score by a standardised mean difference of -1.40 (95% CI -1.83 to -0.96; 2 studies, 101 participants; low-certainty evidence). We were uncertain about the effect of magnesium infusion on improving lung function or oxygen saturation. For all adverse events, the Peto OR was 0.14 (95% CI 0.02 to 1.00; 102 participants); however, the event rate was too low to reach a robust conclusion.  Nebulised magnesium sulfate versus placebo Three studies (20 to 172 participants) were included. Magnesium inhalation may have little to no impact on hospital admission (OR 0.77, 95% CI 0.21 to 2.82; very low-certainty evidence) or need for ventilatory support (NIV or mechanical ventilation) (OR 0.33, 95% CI 0.01 to 8.20; very low-certainty evidence). It may result in fewer ICU admissions compared to placebo (OR 0.39, 95% CI 0.15 to 1.00; very low-certainty evidence) and improvement in dyspnoea (MD -14.37, 95% CI -26.00 to -2.74; 1 study, 20 participants; very low-certainty evidence). There were no serious adverse events reported in either group. There was one reported death in the placebo arm in one trial, but the number of participants was too small for a conclusion. There was limited evidence about the effect of magnesium inhalation on length of hospital stay, lung function outcomes or oxygen saturation. Included studies did not report adverse events.  Magnesium sulfate versus ipratropium bromide  A single study with 124 participants assessed nebulised magnesium sulfate plus intravenous magnesium infusion versus nebulised ipratropium plus intravenous normal saline. There was little to no difference between these groups in terms of hospital admission (OR 1.62, 95% CI 0.78 to 3.37), endotracheal intubation (OR 1.69, 95% CI 0.61 to 4.71) and length of hospital stay (MD 1.10 days, 95% CI -0.22 to 2.42), all with very low-certainty evidence. There were no data available for non-invasive ventilation, ICU admission and serious adverse events. Adverse events were not reported.  AUTHORS' CONCLUSIONS: Intravenous magnesium sulfate may be associated with fewer hospital admissions, reduced length of hospital stay and improved dyspnoea scores compared to placebo. There is no evidence of a difference between magnesium infusion and placebo for NIV, lung function, oxygen saturation or adverse events. We found no evidence for ICU admission, endotracheal intubation, serious adverse events or mortality. For nebulised magnesium sulfate, we are unable to draw conclusions about its effects in COPD exacerbations for most of the outcomes. Studies reported possibly lower ICU admissions and a lesser degree of dyspnoea with magnesium inhalation compared to placebo; however, larger studies are required to yield a more precise estimate for these outcomes. Similarly, we could not identify any robust evidence for magnesium sulfate compared to ipratropium bromide. Future well-designed multicentre trials with larger samples are required, including subgroups according to severity of exacerbations and COPD phenotypes.

Association between annual change in FEV1 and comorbidities or impulse oscillometry in chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is characterized by persistent respiratory symptoms and airflow limitation. The decline in forced expiratory volume in one second (FEV₁) is considered to be one of the most important outcome measures for evaluating disease progression. However, the only intervention proven to improve COPD prognosis is smoking cessation. This study therefore investigated the factors associated with annual FEV₁ decline in COPD.

Methods

This retrospective study followed up 65 patients treated for COPD for 5 years: 13 current smokers and 52 former smokers, 25 with pneumonia, 24 with asthma, 18 with cancer, and 17 with cardiovascular disease. The patients were divided into groups based on clinical cutoff parameters of the impulse oscillometry system (IOS): 11 high and 54 low R5, 8 high and 57 low R20, 21 high and 44 low R5–R20, 26 high and 39 low X5, 38 high and 27 low Fres, and 36 high and 29 low AX. We investigated whether the decline in FEV₁ was associated with comorbidities and IOS parameters.

Results

The annual change in FEV₁ over 5 years was significantly affected by smoking status (current − 66.2 mL/year vs. former − 5.7 mL/year, p < 0.01), pneumonia (with − 31.5 mL/year vs. without − 8.9 mL/year, p < 0.05), asthma (with − 30.2 mL/year vs. − 10.8 mL/year, p < 0.01), but not by cancer and cardiovascular disease. In the groups defined by IOS results, only the high AX group had significantly more annual decline in FEV₁ and %FEV₁ than the low AX group (− 22.1 vs. − 12.8, p < 0.05 and − 0.20 vs. 0.40, p < 0.05, respectively).

Conclusions

Continuing smoking as well as complications in pneumonia and asthma would be risk factors for the progression of COPD. AX might be a suitable parameter to predict the prognosis of patients with COPD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01980-6.

Genetic Associations and Architecture of Asthma-COPD Overlap

BACKGROUND

Some people have characteristics of both asthma and COPD (asthma-COPD overlap), and evidence suggests they experience worse outcomes than those with either condition alone.

RESEARCH QUESTION

What is the genetic architecture of asthma-COPD overlap, and do the determinants of risk for asthma-COPD overlap differ from those for COPD or asthma?

STUDY DESIGN AND METHODS

We conducted a genome-wide association study in 8,068 asthma-COPD overlap case subjects and 40,360 control subjects without asthma or COPD of European ancestry in UK Biobank (stage 1). We followed up promising signals (P < 5 × 10^-6) that remained associated in analyses comparing (1) asthma-COPD overlap vs asthma-only control subjects, and (2) asthma-COPD overlap vs COPD-only control subjects. These variants were analyzed in 12 independent cohorts (stage 2).

RESULTS

We selected 31 independent variants for further investigation in stage 2, and discovered eight novel signals (P < 5 × 10^-8) for asthma-COPD overlap (meta-analysis of stage 1 and 2 studies). These signals suggest a spectrum of shared genetic influences, some predominantly influencing asthma (FAM105A, GLB1, PHB, TSLP), others predominantly influencing fixed airflow obstruction (IL17RD, C5orf56, HLA-DQB1). One intergenic signal on chromosome 5 had not been previously associated with asthma, COPD, or lung function. Subgroup analyses suggested that associations at these eight signals were not driven by smoking or age at asthma diagnosis, and in phenome-wide scans, eosinophil counts, atopy, and asthma traits were prominent.

INTERPRETATION

We identified eight signals for asthma-COPD overlap, which may represent loci that predispose to type 2 inflammation, and serious long-term consequences of asthma.

Asthma-COPD Overlap Syndrome: Recent Insights and Unanswered Questions

The term asthma-COPD overlap (ACO) has been used to identify a heterogeneous condition in which patients present with airflow limitation that is not completely reversible and clinical and inflammatory features of both asthma and chronic obstructive pulmonary disease (COPD). ACO diagnosis may be difficult in clinical practice, while controversy still exists regarding its definition, pathophysiology, and impact. Patients with ACO experience a greater disease burden compared to patients with asthma or COPD alone, but in contrast they show better response to inhaled corticosteroid treatment than other COPD phenotypes. Current management recommendations focus on defining specific and measurable treatable clinical traits, according to disease phenotypes and underlying biological mechanisms for every single patient. In this publication, we review the current knowledge on definition, pathophysiology, clinical characteristics, and management options of ACO.

Self-Reported Physician Diagnosed Asthma with COPD is Associated with Higher Mortality than Self-Reported Asthma or COPD Alone - A Prospective 24-Year Study in the Population of Helsinki, Finland

Asthma and COPD are common chronic obstructive respiratory diseases. COPD is associated with increased mortality, but for asthma the results are varying. Their combination has been less investigated, and the results are contradictory. The aim of this prospective study was to observe the overall mortality in obstructive pulmonary diseases and how mortality was related to specific causes using postal questionnaire data. This study included data from 6,062 participants in the FinEsS Helsinki Study (1996) linked to mortality data during a 24-year follow-up. According to self-reported physician diagnosed asthma, COPD, or smoking status, the population was divided into five categories: combined asthma and COPD, COPD alone and asthma alone, ever-smokers without asthma or COPD and never-smokers without asthma or COPD (reference group). For the specific causes of death both the underlying and contributing causes of death were used. Participants with asthma and COPD had the highest hazard of mortality 2.4 (95% CI 1.7-3.5). Ever-smokers without asthma or COPD had a 9.5 (3.7-24.2) subhazard ratio (sHR) related to lower respiratory tract disease specific causes. For asthma, COPD and combined, the corresponding figures were 10.8 (3.4-34.1), 25.0 (8.1-77.4), and 56.1 (19.6-160), respectively. Ever-smokers without asthma or COPD sHR 1.7 (95% CI 1.3-2.5), and participants with combined asthma and COPD 3.5 (1.9-6.3) also featured mortality in association with coronary artery disease. Subjects with combined diseases had the highest hazard of overall mortality and combined diseases also showed the highest hazard of mortality associated with lower respiratory tract causes or coronary artery causes.Abbreviations: CigCigaretteCOPDChronic obstructive pulmonary diseaseCVDCardiovascular diseaseFEV₁Forced Expiratory Volume in one secondFVCForced Vital CapacityFinEsSFinland, Estonia, and Sweden study on chronic obstructive pulmonary diseasesHRHazard RatiosHRSubhazard RatioICD-10International Statistical Classifications of Diseases and Related Health Problems (Version 10).

Exploring the efficacy and contribution of Dupilumab in asthma management

IgG4 monoclonal antibody Dupilumab binds to the alpha chain (IL4R) of both types of the ligand-binding domains (IL4R/ IL13R1; equally IL4 and IL13 specific) of the IL-4 receptor. The current focus on precision medicine techniques to blocking pathways implicated in allergy disorders is crucial to the development of Dupilumab and broadening its therapeutic uses. Our review describes how the IL-4R complexes signaling pathway works, explores the probable mechanisms of Dupilumab activity and addresses its clinical usefulness and safety in asthma. The FDA (Food and Drug Administration) already licences it to treat Alzheimer's disease and moderate-to-severe asthma, and it has shown highly significant results in the management of chronic rhinosinusitis and Eosinophilic esophagitis (EoE). Previous investigations and clinical trials undertaken by various pharmaceutical firms are examined in this review article to assess the existing literature fully. The discovery of Dupilumab and the expanding range of therapeutic uses are pertinent to the current focus on precision medicine methods to blocking asthma-related pathways.

Home Dust Allergen Exposure Is Associated with Outcomes among Sensitized Individuals with Chronic Obstructive Pulmonary Disease

Rationale: Environmental exposures have been associated with adverse outcomes in chronic obstructive pulmonary disease (COPD). Approximately one-third of individuals with COPD have allergic sensitization, but it is unknown whether exposure to allergens in the home is associated with outcomes. Objectives: To determine the prevalence and associations of allergen sensitization with exposure to common indoor allergens with symptoms and exacerbation risk in COPD. Methods: Allergen sensitization to five common indoor allergens was assessed in former smokers with COPD. Home settled dust was assessed for presence of corresponding allergens. Sensitization and exposure status was determined and associations evaluated in adjusted models with longitudinal outcomes including symptoms, lung function, and exacerbations. Interactions were assessed between sensitization/exposure status and lung function. Measurements and Main Results: One hundred eighty-three individuals studied were on average 67.3 years of age (SD, 8.22) with average FEV1 of 53.2% (SD, 17.6%). Seventy-seven percent of participants were exposed to at least one tested allergen, and 17% had sensitization with corresponding allergen exposure. After adjustment, sensitization with exposure was associated with lower lung function (β, -8.29; 95% confidence interval [CI], -14.80 to -1.77), higher St. George's Respiratory Questionnaire Total Score (β, 6.71; 95% CI, 0.17 to 13.25), and higher exacerbation risk (odds ratio, 2.31; 95% CI, 1.11 to 4.79). Associations appeared to be more pronounced among individuals with lower lung function. Conclusions: Allergen exposures are common in COPD and associated with adverse outcomes among those with concomitant allergen sensitization. This study establishes allergens as an important home exposure that potentially could be addressed with comprehensive home environmental modification strategies to improve COPD outcomes.

Sleep problems and associations with cardiovascular disease and all-cause mortality in asthma-COPD overlap: analysis of the National Health and Nutrition Examination Survey (2007-2012)

STUDY OBJECTIVES

The impact of sleep problems (i.e. sleep duration and presence of sleep disorders) on cardiovascular morbidity and all-cause mortality in adults with asthma-COPD overlap (ACO) is unknown.

METHODS

Using the National Health and Nutrition Examination Survey (NHANES) database (2007-2012 cycles) and National Death Index data, we identified 398 persons with ACO. Data on self-reported physician-diagnosed sleep disorder and cardiovascular disease were collected. Sleep duration in hours was categorized as short (≤5), normal (6-8), and long (≥9). Associations between sleep duration and presence of sleep disorders and cardiovascular disease and all-cause mortality were analyzed in regression models adjusted for age, sex, race, smoking status, and body mass index.

RESULTS

Presence of sleep disorders was more commonly reported in the ACO group (24.7%) compared to all other groups. The ACO group had a higher proportion of short sleepers (27.6%) compared to controls (11.7%) and COPD (19.2%) and a higher proportion of long sleepers (6.9%) compared to COPD (5.5%). Presence of sleep disorders was associated with increased risk for CVD (OR = 2.48, 95% CI, 1.65 - 3.73) and death (HR = 1.44, 95% CI, 1.03 - 2.02); risk did not vary between groups. A stronger association existed between sleep duration and increased risk for CVD and all-cause mortality in ACO as compared to COPD and controls.

CONCLUSIONS

These results suggest that persons with ACO may represent a high-risk group that should be targeted for more aggressive intervention of sleep problems, a modifiable risk factor.

Current Status of Studies Investigating Asthma-Chronic Obstructive Pulmonary Disease Overlap in Korea: A Review

There is a considerable number of individuals who exhibit features of both asthma and chronic obstructive pulmonary disease (COPD), defined as asthma-COPD overlap (ACO). Many studies have reported that these patients have a greater burden of symptoms, including cough and dyspnea, and experience more exacerbations and hospitalizations than those with non-ACO COPD or asthma. Although diagnostic criteria for ACO have not yet been clearly established, their clinical significance remains to be determined. As interest in ACO grows, related studies have been conducted in South Korea as well. The present review summarizes ACO-related studies in South Korea to better understand Korean ACO patients and guide further research. Several cohort studies of asthma and COPD and population-based studies for ACO were reviewed and the key results from demographics, clinical features, lung function, biomarkers, treatment, and prognosis were summarized.

Eosinophilic endotype of chronic obstructive pulmonary disease: similarities and differences from asthma

Approximately 25% to 40% of patients with chronic obstructive pulmonary disease (COPD) have the eosinophilic endotype. It is important to identify this group accurately because they are more symptomatic and are at increased risk for exacerbations and accelerated decline in forced expiratory volume in the 1st second. Importantly, this endotype is a marker of treat ment responsiveness to inhaled corticosteroid (ICS), resulting in decreased mortality risk. In this review, we highlight differences in the biology of eosinophils in COPD compared to asthma and the different definitions of the COPD eosinophilic endotype based on sputum and blood eosinophil count (BEC) with the corresponding limitations. Although BEC is useful as a biomarker for eosinophilic COPD endotype, optimal BEC cut-offs can be combined with clinical characteristics to improve its sensitivity and specificity. A targeted approach comprising airway eosinophilia and appropriate clinical and physiological features may improve identification of subgroups of patients who would benefit from biologic therapy or early use of ICS for disease modification.

Long-term safety and efficacy of dupilumab in patients with moderate-to-severe asthma (TRAVERSE): an open-label extension study

BACKGROUND

Clinical trials have shown treatment benefits of dupilumab in patients with uncontrolled asthma for up to 1 year. This study aimed to evaluate the long-term safety and efficacy of dupilumab in patients with moderate-to-severe asthma, as data for extended treatment with dupilumab beyond 1 year are not available.

METHODS

TRAVERSE was an open-label extension study in 362 hospitals and clinical centres across 27 countries that assessed the safety and efficacy of dupilumab 300 mg every 2 weeks up to 96 weeks in adults and adolescents (aged 12-84 years) with moderate-to-severe or oral-corticosteroid-dependent severe asthma who had completed a previous dupilumab asthma study (phase 2A EXPEDITION, phase 2B DRI [P2b], phase 3 QUEST, or VENTURE). The primary endpoint was the number and percentage of patients with any treatment-emergent adverse events. Secondary endpoints included annualised exacerbation rate (AER) over the treatment period and change from parent study baseline in pre-bronchodilator FEV₁, the five-item asthma control questionnaire (ACQ-5), the asthma quality of life questionnaire (AQLQ), type 2 biomarkers (blood eosinophils and serum total IgE), and anti-drug antibodies (ADAs). Statistical analyses were descriptive. We report safety in all enrolled patients, and efficacy in patients with non-oral-corticosteroid-dependent asthma and in subgroups, including patients with a type 2 inflammatory phenotype who received 148 weeks of treatment. This study is registered with ClinicalTrials.gov, NCT02134028.

FINDINGS

Between Aug 5, 2014, and Oct 11, 2019, of 2302 patients assessed for eligibility, 2282 adults and adolescents were enrolled (median age 50 years, 62·1% female and 37·9% male). Safety during TRAVERSE was consistent with the known dupilumab safety profile. The proportion of patients reporting treatment-emergent adverse events throughout the study duration was similar to that observed in the parent studies and ranged from 76·3% to 94·7%. The most frequently reported treatment-emergent adverse events were nasopharyngitis (17·5-25·9%), injection-site erythema (2·2-23·4%), and bronchitis (9·3-19·0%). Serious asthma exacerbations (0·5-3·6%) and pneumonia (0·7-2·7%) were the most frequently reported serious adverse events. There were four treatment-emergent adverse events leading to death. Efficacy during TRAVERSE was also consistent with the results of parent studies. In patients who were non-oral-corticosteroid-dependent, AER remained low (0·277-0·327) across parent study and treatment groups, pre-bronchodilator FEV₁ improvements were sustained to the end of treatment at week 96 (mean changes from parent study baseline ranged from 0·22 L [SD 0·44] to 0·33 L [0·44] across parent study and treatment groups), and improvements in ACQ-5 and AQLQ scores were sustained to the last timepoint assessed at week 48. Rapid improvements were observed in pre-bronchodilator FEV₁ and sustained improvements were seen in all outcome measures for patients given dupilumab who previously received placebo in parent studies; further improvements in AER, asthma control, and health-related quality of life were observed in patients who continued receiving dupilumab. Blood eosinophils and serum total IgE decreased progressively. ADA status had no effect on safety or efficacy. In the subgroup of patients with a type 2 inflammatory phenotype followed-up for 148 weeks, AER decreased progressively, and initial lung function improvements were sustained over 148 weeks.

INTERPRETATION

Data show that safety and efficacy of dupilumab in adult and adolescent patients with moderate-to-severe asthma are sustained when treatment is extended up to 148 weeks. These findings therefore support the long-term use of dupilumab in this patient population.

FUNDING

Sanofi and Regeneron Pharmaceuticals.

Current Knowledge of Asthma-COPD Overlap (ACO) Genetic Risk Factors, Characteristics, and Prognosis

Asthma-COPD overlap (ACO) is a newly identified phenotype of chronic obstructive airway diseases with shared asthma and COPD features. Patients with ACO are poorly defined, and some evidence suggests that they have worse health outcomes and greater disease burden than patients with COPD or asthma. Generally, there is no evidence-based and universal definition for ACO; several consensus documents have provided various descriptions of the phenotype. In addition, the mechanisms underlying the development of ACO are not fully understood. Whether ACO is a distinct clinical entity with its particular discrete genetic determinant different from asthma and COPD alone or an intermediate phenotype with overlapping genetic markers within asthma and COPD spectrum of obstructive airway disease remains unproven. This review summarizes the current knowledge of the genetic risk factors, characteristics, and prognosis of ACO.

Asthma and COPD versus phenotypic traits: Toward precision medicine in chronic airway disease

BACKGROUND

Asthma and COPD diagnoses are used to classify chronic airway diseases; however, both diseases are related to phenotypic traits like allergy, obesity, cough, sputum production, low-grade inflammation, smoking, elevated blood eosinophil count, comorbidities, and occupational exposures. Whether such traits can replace asthma and COPD diagnoses when assessing risk of exacerbation is unclear. We tested the hypothesis that individuals with either asthma or COPD diagnoses have similar risk of moderate and severe exacerbations when adjusted for differences in phenotypic traits.

METHODS

From the Copenhagen General Population Study, a cohort study of the general population, we included 7190 individuals with chronic airway disease. Phenotypic traits were recorded at baseline and risk of exacerbations was assessed during follow-up from 2003 to 2013.

RESULTS

The incidence rate ratio (IRR) of moderate exacerbations in individuals with clinical COPD was 1.61 (95% Confidence Interval, 1.27-2.02) compared to individuals with asthma in a model only adjusted for age, sex, and education, but after the inclusion of phenotypic traits IRR was 1.05 (0.82-1.35). Corresponding IRRs of severe exacerbations in individuals with clinical COPD versus asthma were 3.82 (2.73-5.35) and 2.28 (1.63-3.20), respectively.

CONCLUSIONS

When taking phenotypic traits into account, individuals with asthma and COPD had comparable risk of moderate exacerbations; however, corresponding risk of severe exacerbations was higher in individuals with COPD than in those with asthma.

Update on Asthma-COPD Overlap (ACO): A Narrative Review

Although chronic obstructive pulmonary disease (COPD) and asthma are well-characterized diseases, they can coexist in a given patient. The term asthma-COPD overlap (ACO) was introduced to describe patients that have clinical features of both diseases and may represent around 25% of COPD patients and around 20% of asthma patients. Despite the increasing interest in ACO, there are still substantial controversies regarding its definition and its position within clinical guidelines for patients with obstructive lung disease. In general, most definitions indicate that ACO patients must present with non-reversible airflow limitation, significant exposure to smoking or other noxious particles or gases, together with features of asthma. In patients with a primary diagnosis of COPD, the identification of ACO has therapeutic implication because the asthmatic component should be treated with inhaled corticosteroids and some studies suggest that the most severe patients may respond to biological agents indicated for severe asthma. This manuscript aims to summarize the current state-of-the-art of ACO. The definitions, prevalence, and clinical manifestations will be reviewed and some innovative aspects, such as genetics, epigenetics, and biomarkers will be addressed. Lastly, the management and prognosis will be outlined as well as the position of ACO in the COPD and asthma guidelines.

Asthma/obstructive pulmonary disease overlap: update on definition, biomarkers, and therapeutics

PURPOSE OF REVIEW

Asthma/chronic obstructive pulmonary disease overlap (ACO) continues to be a poorly understood condition. This review discusses newly proposed criteria and potential biomarkers in ACO, to aid in diagnosis and research studies, and prudent therapeutic approaches.

RECENT FINDINGS

A global expert panel proposed an operational definition consisting of major and minor criteria as a step toward defining ACO. Serum periostin and YKL-40 may serve as biomarkers for ACO. Clinically, a reasonable therapeutic approach to ACO is the early addition of a long-acting β-agonist (LABA) and/or a long-acting muscarinic antagonist (LAMA) to an inhaled corticosteroid (ICS).

SUMMARY

Both the proposed criteria and the described biomarkers for ACO can help guide clinicians in identifying this condition as well as aid researchers in designing much needed future studies. In the meantime, clinicians can treat potential ACO patients using the above approach, until therapeutic studies in clearly defined ACO patients are performed.

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 coexistence of asthma and COPD: risk factors, clinical history and lung function trajectories

RATIONALE

Patients with concomitant features of asthma and chronic obstructive pulmonary disease (COPD) have a heavy disease burden.

OBJECTIVES

Using data collected prospectively in the European Community Respiratory Health Survey, we compared the risk factors, clinical history, and lung function trajectories from early adulthood to the late sixties of middle aged subjects having asthma+COPD (n=179), past (n=263) or current (n=808) asthma alone, COPD alone (n=111), or none of these (n=3477).

METHODS

Interview data and prebronchodilator FEV₁ and FVC were obtained during three clinical examinations in 1991-1993, 1999-2002, and 2010-2013. Disease status was classified in 2010-2013, when the subjects were aged 40-68, according to the presence of fixed airflow obstruction (postbronchodilator FEV₁/FVC below the lower limit of normal), a lifetime history of asthma, and cumulative exposure to tobacco or occupational inhalants. Previous lung function trajectories, clinical characteristics, and risk factors of these phenotypes were estimated.

MAIN RESULTS

Subjects with asthma+COPD reported maternal smoking (28.2%) and respiratory infections in childhood (19.1%) more frequently than subjects with COPD alone (20.9 and 14.0%, respectively). Subjects with asthma+COPD had an impairment of lung function at age 20 that tracked over adulthood, and more than half of them had asthma onset in childhood. Subjects with COPD alone had the highest lifelong exposure to tobacco smoking and occupational inhalants, and they showed accelerated lung function decline during adult life.

CONCLUSIONS

The coexistence between asthma and COPD seems to have its origins earlier in life compared to COPD alone. These findings suggest that prevention of this severe condition, which is typical at older ages, should start in childhood.