Differentiating COPD from asthma in clinical practice

Association between antibiotics and asthma risk among adults aged over 40 years: a nationally representative retrospective cohort study

INTRODUCTION

Several studies have reported that exposure to antibiotics can lead to asthma during early childhood. However, the association between antibiotic use and risk of asthma in the adult population remains unclear. This study aimed to investigate the association between antibiotic use and asthma in adults.

METHODS

We used data from the National Health Insurance Service (NHIS)-Health Screening Cohort, which included participants aged ≥40 years who had health screening examination data in 2005-2006. A total of 248 961 participants with a mean age of 55.43 years were enrolled in this retrospective cohort study. To evaluate antibiotic exposure from the NHIS database for 5 years (2002-2006), cumulative usage and multiclass prescriptions were identified, respectively. During the follow-up period (2007-2019), 42 452 patients were diagnosed with asthma. A multivariate Cox proportional hazard regression model was used to assess the association between antibiotic use and newly diagnosed asthma.

RESULTS

Participants with antibiotic use for ≥91 days showed a higher risk of asthma (adjusted HR (aHR) 1.84, 95% CI 1.72 to 1.96) compared with participants who did not use antibiotics (n=38 450), with a duration-dependent association (ptrend<0.001). Furthermore, ≥4 antibiotic class user group had an increased risk of asthma (aHR 1.44, 95% CI 1.39 to 1.49) compared with one class of antibiotic use (n=64 698). Also, one class of antibiotic use had a higher risk of asthma (aHR 1.21, 95% CI 1.17 to 1.26) compared with non-users, and it also showed a duration-dependent relationship in all classes, including 1, 2, 3 and ≥4 class group (ptrend<0.001). The duration-response relationship between antibiotic use and increased risk of asthma remained in our sensitivity analyses with the washout and shifting of the index date.

CONCLUSIONS

The duration-response pattern observed in antibiotic use and asthma may suggest the implication of proper antibiotic use and management in adults.

Recognition of diabetes and sociodemographic predictors: results of a cross-sectional nationwide population-based survey in Singapore

OBJECTIVE

To assess recognition of diabetes among a nationally representative multiethnic sample of Singapore's general public. Also, to explore the sociodemographic predictors associated with the ability to correctly recognise diabetes.

DESIGN AND SETTING

This was a cross-sectional vignette-based survey. Respondents were instructed to read the vignette, then answer the open-ended question, 'What do you think the person in the vignette is suffering from?'

PARTICIPANTS

A sample of 2895 household residents aged 18 years and above, of which 436 were persons with diabetes.

RESULTS

82.7% could correctly recognise diabetes in the vignette. Overall, recognition was significantly higher among respondents aged 35-49 years (OR 1.85, 95% CI 1.15 to 2.98), 50-64 years (OR 2.06, 95% CI 1.19 to 3.56), ethnic Malays (OR 1.39, 95% CI 1.02 to 1.89) and persons with diabetes (OR 2.64, 95% CI 1.38 to 5.08). By contrast, male (OR 0.64, 95% CI 0.46 to 0.90), ethnic Others (OR 0.59, 95% CI 0.37 to 0.93) and the unemployed (OR 0.48, 95% CI 0.25 to 0.92) were significantly associated with poor recognition of diabetes.

CONCLUSION

Overall public recognition of diabetes was high, but the significant gaps in knowledge in certain demographic groups were of concern. Public health interventions aimed at preventing and controlling diabetes should continue to target all members of the population with accurate and appropriate information. Ongoing efforts of diabetes awareness and screening programmes need to be improved, particularly for young adults, males and the unemployed.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

Pulmonary rehabilitation for obstructive lung disease

Pulmonary rehabilitation (PR) is a highly effective, established therapy to improve exercise intolerance, impaired quality of life and limb muscle weakness associated with a range of chronic respiratory diseases. The evidence base for PR is largest in the area of chronic obstructive pulmonary disease (COPD), yet its role in other obstructive lung diseases such as asthma is less well defined. Despite several features being common across both COPD and asthma, factors such as younger age or employment may affect the potential applicability of traditional PR models for patients with asthma. This review examines the current evidence regarding PR for the obstructive lung diseases of COPD and asthma. It offers appraisal of some of the strengths and weaknesses of existing literature, identifies areas in need of future research and details some of the issues facing clinicians responsible for the clinical management and rehabilitation of patients with these diseases.

Comparing physical and mental health literacy

BACKGROUND

This study attempted to ascertain whether people had better mental vs physical health literacy by comparing their knowledge of six conditions.

AIMS

The aim was to link two different literatures which have remained apart.

METHODS

In all, 186 young British participants (52% male) with an average age of 25 years completed an online questionnaire describing six vignettes characters. Three described mental health conditions (anorexia, bipolar disorder and schizophrenia) and three physical health conditions (asthma, diabetes and osteoarthritis). Participants were required to name the illness and rate how treatable and manageable they believed the condition is. They were also asked to rate how much the problem would affect an individual's daily life and suggest whether the individual should seek professional help.

RESULTS

The recognition of specific mental health conditions (anorexia, borderline personality disorder, schizophrenia) was marginally higher than the recognition of physical health conditions (arthritis, asthma, diabetes). Ratings about treatment and the effect of each illness showed considerable variation.

CONCLUSION

The results suggest that people are equally and relatively poorly informed about relatively common mental compared to physical illnesses.

Development of a validated LC- MS/MS method for the quantification of 19 endogenous asthma/COPD potential urinary biomarkers

Obstructive airways inflammatory diseases sometimes show overlapping symptoms that hinder their early and correct diagnosis. Current clinical tests are tedious and are of inadequate specificity in special population such as the elderly and children. Therefore, we are developing tandem mass spectrometric (MS/MS) methods for targeted analysis of urine biomarkers. Recently, proton-nuclear magnetic resonance (¹H-NMR) analysis proposed 50 urinary metabolites as potential diagnostic biomarkers among asthma and chronic obstructive pulmonary disease (COPD) patients. Metabolites are divided into 3 groups based on chemical nature. For group 1 (amines and phenols, 19 urinary metabolites), we developed and validated a high performance liquid chromatographic (HPLC)-MS/MS method using differential isotope labeling (DIL) with dansyl chloride. Method development included the optimization of the derivatization reaction, the MS/MS conditions, and the chromatographic separation. Linearity varied from 2 to 4800 ng/mL and the use of ¹³C₂-labeled derivatives allowed for the correction of matrix effects as well as the unambiguous confirmation of the identity of each metabolite in the presence of interfering isomers in urine. Despite the challenges associated with method validation, the method was fully validated as per the food and drug administration (FDA) and the European medicines agency (EMA) recommendations. Validation criteria included linearity, precision, accuracy, dilution integrity, selectivity, carryover, and stability. Challenges in selectivity experiments included the isotopic contributions of the analyte towards its internal standard (IS), that was addressed via the optimization of the IS concentration. In addition, incurred sample analysis was performed to ensure that results from patient samples are accurate and reliable. The method was robust and reproducible and is currently being applied in a cohort of asthma and COPD patient urine samples for biomarker discovery purposes.

Asthma and COPD: Similarities and Differences in the Pathophysiology, Diagnosis and Therapy

Asthma and chronic obstructive pulmonary disease (COPD) are two of the most common chronic lung diseases worldwide. Distinguishing between these different pulmonary diseases can be difficult in practice because of symptomatic similarities. A definitive diagnosis is essential for correct treatment. This review article presents the different symptoms of these two chronic inflammatory lung diseases following a selective search of the PubMed database for relevant literature published between 1996 and 2012. While cough occurs in both diseases, asthmatics often have a dry cough mainly at night, which is often associated with allergies. In contrast, COPD is usually caused by years of smoking. Paroxysmal dyspnea, which occurs in asthma, is characterized by shortness of breath, while in COPD it occurs during physical exertion in early stages and at rest in later stages of the disease. Asthma often begins in childhood or adolescence, whereas COPD occurs mainly in smokers in later life. It is possible to live with asthma into old age, whereas the life expectancy of patients with COPD is significantly limited. Currently, there is no general curative treatment for either disorder.

Clinically remitted childhood asthma is associated with airflow obstruction in middle-aged adults

BACKGROUND AND OBJECTIVE

While adult asthma has been shown to be a risk factor for COPD, the effect of remitted childhood asthma on adult lung function has not been clarified. The aim of this study was to examine whether remitted childhood asthma is a risk factor for airflow obstruction in a middle-aged general population.

METHODS

A total of 9896 participants (range: 35-60 years) from five healthcare centres were included in the study. The participants were classified into four categories based on the presence or absence of physician-diagnosed childhood/adulthood asthma and asthma symptoms as follows: healthy controls (n = 9154), remitted childhood asthma (n = 287), adulthood-onset asthma (n = 354) and childhood-adulthood asthma (n = 101).

RESULTS

The prevalence of respiratory symptoms was similar in both the participants with remitted childhood asthma and healthy controls. The prevalence of airflow obstruction (forced expiratory volume in 1 s (FEV₁ )/forced vital capacity (FVC) < 0.7) was significantly higher in the participants with remitted childhood asthma, those with adult-onset asthma and those with childhood-adulthood asthma (5.2%, 14.4% and 16.8%, respectively) compared with healthy controls (2.2%). Multivariate logistic regression showed that remitted childhood asthma was independently associated with airflow obstruction. Among the participants with remitted childhood asthma, ever-smokers had significantly lower FEV₁ /FVC than never-smokers.

CONCLUSION

Clinically remitted childhood asthma is associated with airflow obstruction in middle-aged adults. Smoking and remitted childhood asthma may be additive factors for the development of airflow obstruction.

Understanding asthma-chronic obstructive pulmonary disease overlap syndrome

Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is a loosely-defined clinical entity referring to patients who exhibit characteristics of both asthma and chronic obstructive pulmonary disease (COPD). Clinical definitions and classifications for ACOS vary widely, which impacts our understanding of prevalence, diagnosis and treatment of the condition. This literature review was therefore conducted to characterize the prevalence of ACOS and the effect of different disease definitions on these estimates, as this has not previously been explored. From an analysis of English language literature published from 2000 to 2014, the estimated prevalence of ACOS ranges from 12.1% to 55.2% among patients with COPD and 13.3%-61.0% among patients with asthma alone. This variability is linked to differences in COPD and asthma diagnostic criteria, disease ascertainment methods (spirometry-based versus clinical or symptom-based diagnoses and claims data), and population characteristics including age, gender and smoking. Understanding the reasons for differences in prevalence estimates of ACOS across the literature may help guide decision making on the most appropriate criteria for defining ACOS and aid investigators in designing future ACOS clinical studies aimed at effective treatment.

Characteristics of prevalent and new COPD cases in Greece: the GOLDEN study

Background

Greece has one of the highest rates of smoking and chronic obstructive pulmonary disease (COPD) in Europe.

Aim

The study aimed to record both the disease characteristics among a sample of Greek COPD patients and the nationwide rates of newly diagnosed COPD cases.

Methods

In this noninterventional, epidemiological cross-sectional study, a representative nationwide sample of 45 respiratory centers provided data on the following: 1) the demographic and clinical characteristics of COPD patients and 2) newly diagnosed COPD cases monitored over a period of 6 months by each physician.

Results

Data from 6,125 COPD patients were collected. Advanced age (median age: 68 years), male predominance (71.3%), largely overweight status with median body mass index (BMI) =27.5 kg/m², high percentage of current and ex-smokers (89.8%), and presence of comorbidities (81.9%) were evident in the sample. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 criteria, majority of the COPD patients had moderate or severe airflow limitation (61%). Severity of airflow limitation was significantly associated with older age, male sex, obesity, ex-smoking status, and presence of comorbidity (all P-values <0.001). A total of 61.3% of the patients received medication, mostly bronchodilators (64.4%) and fixed-dose combinations of long-acting β₂-agonists and inhaled corticosteroids (39.9%), while 35.9% reported taking medication on demand. The majority (81.1%) of patients reported a preference for fewer inhalations of their bronchodilator therapy. Based on the mixed-effect Poisson model, the rate of newly diagnosed COPD cases was estimated to be 18.2% (95% confidence interval: 14.9–22.3) per pulmonologist/3 months. Of those newly diagnosed, the majority of patients had mild or moderate airflow limitation (78.2%).

Conclusion

The Greek Obstructive Lung Disease Epidemiology and health ecoNomics study reflected the real-life profile of COPD patients and provided evidence on the profile of new COPD cases in Greece. Various demographic factors were delineated, which can assist in designing more effective diagnostic and management strategies for COPD in Greece.

Active asthma and the prevalence of physician-diagnosed COPD

INTRODUCTION

Despite the considerable overlap of asthma and chronic obstructive pulmonary disease (COPD), the extent to which the two diagnoses are the manifestations of the same disease remains unresolved. We conducted these analyses to evaluate the role of active asthma in the prevalence of physician-diagnosed COPD.

METHODS

From 2006 through 2010, 74,209 adults aged 18-99 years and with a history of asthma participated in the Behavioral Risk Factor Surveillance System (BRFSS) Asthma Call-back Survey and responded to interview-administered questionnaires via telephone. We used publicly available data from 71,639 (97%) participants to identify respondents with and without active manifestations of asthma and self-reported, physician-diagnosed COPD. We generated population-weighted estimates of physician-diagnosed COPD prevalence and conducted linear regression to estimate associations between active asthma status and the prevalence of COPD among current smokers, former smokers, and lifetime nonsmokers separately.

RESULTS

Physician-diagnosed COPD was reported in an estimated 29% of the population with any history of asthma, including both active and inactive asthma. Age-specific prevalences of physician-diagnosed COPD were consistently higher among adults with active asthma than adults without active asthma. Compared to inactive asthma, active asthma was associated with an 8.3% [95% confidence interval (CI) 6.1, 10.5] higher prevalence of physician-diagnosed COPD among lifetime nonsmokers, a 20.6% (95% CI 18.0, 23.3) higher prevalence among former smokers, and a 26.7% (95% CI 22.5, 30.9) higher prevalence among current smokers.

CONCLUSIONS

Among adults with a history of asthma, active manifestations of asthma may play an important role in the epidemiology of COPD.

Evaluation of atopy in patients with COPD

OBJECTIVE

To determine the prevalence of atopy and to evaluate clinical, laboratory, and radiological profiles in patients with COPD.

METHODS

This was a cross-sectional study involving outpatients with stable COPD (defined by the clinical history and a post-bronchodilator FEV1/FVC < 70% of the predicted value). The patients completed a questionnaire regarding clinical characteristics and atopy, after which they underwent nasal lavage cytology, skin prick testing, chest X-rays, arterial blood gas analyses, and determination of total serum IgE.

RESULTS

Of the 149 subjects studied, 53 (35.6%), 49 (32.8%), and 88 (59.1%) presented with nasal eosinophilia, a positive skin prick test result, and symptoms of allergic rhinitis, respectively. Correspondence analysis confirmed these findings, showing two distinct patterns of disease expression: atopy in patients with COPD that was less severe; and no evidence of atopy in those with COPD that was more severe (reduced FEV1 and hyperinflation). There was a statistically significant association between nasal eosinophilia and a positive bronchodilator response.

CONCLUSIONS

Using simple and reproducible methods, we were able to show that there is a high frequency of atopy in patients with COPD. Monitoring inflammation in the upper airways can be a useful tool for evaluating respiratory diseases in the elderly and in those with concomitant asthma and COPD, a clinical entity not yet fully understood.

Computer quantification of airway collapse on forced expiration to predict the presence of emphysema

Background

Spirometric parameters are the mainstay for diagnosis of COPD, but cannot distinguish airway obstruction from emphysema. We aimed to develop a computer model that quantifies airway collapse on forced expiratory flow–volume loops. We then explored and validated the relationship of airway collapse with computed tomography (CT) diagnosed emphysema in two large independent cohorts.

Methods

A computer model was developed in 513 Caucasian individuals with ≥15 pack-years who performed spirometry, diffusion capacity and CT scans to quantify emphysema presence. The model computed the two best fitting regression lines on the expiratory phase of the flow-volume loop and calculated the angle between them. The collapse was expressed as an Angle of collapse (AC) which was then correlated with the presence of emphysema. Findings were validated in an independent group of 340 individuals.

Results

AC in emphysema subjects (N = 251) was significantly lower (131° ± 14°) compared to AC in subjects without emphysema (N = 223), (152° ± 10°) (p < 0.0001). Multivariate regression analysis revealed AC as best indicator of visually scored emphysema (R² = 0.505, p < 0.0001) with little significant contribution of K_CO, %predicted and FEV_1, %predicted to the total model (total R² = 0.626, p < 0.0001). Similar associations were obtained when using CT-automated density scores for emphysema assessment. Receiver operating characteristic (ROC) curves pointed to 131° as the best cut-off for emphysema (95.5% positive predictive value, 97% specificity and 51% sensitivity). Validation in a second group confirmed the significant difference in mean AC between emphysema and non-emphysema subjects. When applying the 131° cut-off, a positive predictive value of 95.6%, a specificity of 96% and a sensitivity of 59% were demonstrated.

Conclusions

Airway collapse on forced expiration quantified by a computer model correlates with emphysema. An AC below 131° can be considered as a specific cut-off for predicting the presence of emphysema in heavy smokers.

Construction of a computable cell proliferation network focused on non-diseased lung cells

BACKGROUND

Critical to advancing the systems-level evaluation of complex biological processes is the development of comprehensive networks and computational methods to apply to the analysis of systems biology data (transcriptomics, proteomics/phosphoproteomics, metabolomics, etc.). Ideally, these networks will be specifically designed to capture the normal, non-diseased biology of the tissue or cell types under investigation, and can be used with experimentally generated systems biology data to assess the biological impact of perturbations like xenobiotics and other cellular stresses. Lung cell proliferation is a key biological process to capture in such a network model, given the pivotal role that proliferation plays in lung diseases including cancer, chronic obstructive pulmonary disease (COPD), and fibrosis. Unfortunately, no such network has been available prior to this work.

RESULTS

To further a systems-level assessment of the biological impact of perturbations on non-diseased mammalian lung cells, we constructed a lung-focused network for cell proliferation. The network encompasses diverse biological areas that lead to the regulation of normal lung cell proliferation (Cell Cycle, Growth Factors, Cell Interaction, Intra- and Extracellular Signaling, and Epigenetics), and contains a total of 848 nodes (biological entities) and 1597 edges (relationships between biological entities). The network was verified using four published gene expression profiling data sets associated with measured cell proliferation endpoints in lung and lung-related cell types. Predicted changes in the activity of core machinery involved in cell cycle regulation (RB1, CDKN1A, and MYC/MYCN) are statistically supported across multiple data sets, underscoring the general applicability of this approach for a network-wide biological impact assessment using systems biology data.

CONCLUSIONS

To the best of our knowledge, this lung-focused Cell Proliferation Network provides the most comprehensive connectivity map in existence of the molecular mechanisms regulating cell proliferation in the lung. The network is based on fully referenced causal relationships obtained from extensive evaluation of the literature. The computable structure of the network enables its application to the qualitative and quantitative evaluation of cell proliferation using systems biology data sets. The network is available for public use.

Optimizing chronic obstructive pulmonary disease management in primary care

Diagnosis of chronic obstructive pulmonary disease (COPD) in primary care is complex, as many clinical symptoms are similar to asthma and heart disease, which may lead to misdiagnosis and suboptimal disease management. Spirometry is the best method for diagnosing COPD and distinguishing between COPD, asthma, and cardiovascular diseases. Airway obstruction is fully reversible in asthma, but not in COPD, and can be confirmed when the postbronchodilator ratio of forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) is <0.7. Knowledge of COPD treatment guidelines and a proactive attitude toward disease management by primary care physicians are key to improving symptom control and patients' quality of life. Identification of the appropriate drug/inhaler combination, patient education, training on inhaler use followed by regular monitoring, and pulmonary rehabilitation are also vital to successful COPD management. This review outlines steps to aid physicians in devising and implementing an optimal management plan for COPD patients.

Pulmonary function tests, sputum induction, and bronchial provocation tests: diagnostic tools in the challenge of distinguishing asthma and COPD phenotypes in clinical practice

BACKGROUND

despite a number of important differences in the pathogenesis, course, and prognosis, asthma and chronic obstructive pulmonary disease (COPD) have many features in common. Furthermore, smoking induces considerable overlap in pathogenesis and clinical features between these conditions. This study aimed to reveal what inflammatory patterns prevail in clinically established diagnosis groups, including overlap phenotypes of asthma and COPD, and to evaluate the correlation with airway reversibility and hyperreactivity in these overlapping conditions.

METHODS

a total of 110 patients (17 healthy subjects; 16 "healthy" smokers; 46 asthma patients: 24 smokers and 22 non-smokers; and 31 COPD patients: 10 COPD patients with reversibility and 21 without) participated in the study. Induced sputum, reversibility testing, methacholine and adenosine 5'monophosphate (AMP) provocation challenges, and skin prick testing were performed. Airways inflammation was assessed by differential cell counts, and cytokines (interleukin-8 [IL-8] and tumor necrosis factor-alpha [TNF-α]) were measured in induced sputum by enzyme-linked immunosorbent assay (ELISA).

RESULTS

COPD patients with reversibility had increased sputum neutrophils, IL-8, and TNF-α levels compared to smoking asthmatics. No difference was found in inflammatory cells and cytokines between COPD subgroups. Sputum neutrophilia was inversely correlated with the change in forced expiratory volume in one second (ΔFEV(1)) in smoking asthmatic patients (r = -0.563, P = 0.036). No correlation was found between airway hyperresponsiveness (AHR), either with methacholine or AMP, and inflammation in asthmatic patients, regardless of smoking. Reversibility was not correlated with inflammation in COPD patients. However, the response to AMP challenge was correlated with sputum neutrophils (r = 0.844, P = 0.001).

CONCLUSION

although overlaps exist in the disease characteristics of asthma and COPD, the combination of lung function testing, sputum induction, and AHR reveals information that facilitates the distinction between these diseases, allowing clinicians to better tailor their therapy.

Evaluation of obstructive lung disease with vibration response imaging

As optimal treatment and prognosis differ between asthma and COPD, a new diagnostic approach to differentiating between the two disorders would be clinically desirable. We evaluated the utility of vibration response imaging in differentiating between asthma and COPD. Sixty-six subjects with asthma or COPD were recorded, before and after the administration of a short-acting bronchodilator, using a computerized lung sound analysis device. Gray-scale images of breath sound distribution in the lungs, quantitative data in breath sound graphs (timing, amplitude) and automatic crackle and wheeze detection programs were used to differentiate between asthma and COPD subjects. Imaging data were compared with the clinical diagnosis, made by the standard methods (medical history, physical examination, and spirometric indices). Blinded evaluation of images demonstrated a significantly higher rate of improvement in image dynamics, shape and overall improvement following bronchodilator in subjects with asthma compared with those with COPD. Quantitative data showed distinct patterns in timing and amplitude for these two pathologies. Combined analyses based on qualitative image evaluation and quantitative data demonstrated an overall 85% accuracy (84% for asthma, 86% for COPD) in differentiating between asthma and COPD. Combined qualitative and quantitative evaluations of lung sounds are quite sensitive in distinguishing between lung sound recordings of COPD and asthma individuals. Lung sound features of synchronization in timing and intensity provide objective data that may further differentiate these two airway disorders.