COPD exacerbations: causes, prevention, and treatment

Comprehensive comorbidity assessment for the ECOPD: a long-term multi-centre retrospective study

BACKGROUND

Exacerbation of chronic obstructive pulmonary disease (ECOPD) results in severe adverse outcomes and mortality. It is often associated with increased local and systemic inflammation. However, individual susceptibility to exacerbations remains largely unknown. Our study aimed to investigate the association between comorbidities and exacerbation outcomes.

METHODS

We included patients with the primary discharge diagnosis of exacerbation for more 10 years in China. Data on all comorbidities were collected and analysed to determine the impact of the comorbidities on 1-year exacerbation readmission, length of hospital stay, and hospital cost. Univariable and multivariable logistic regression analyses were performed, and predictive models were developed.

RESULTS

This extensive investigation evaluated a total of 15,708 individuals from five prominent locations in China, revealing notable variations in the prevalence of comorbidities and healthcare expenses among different regions. The study shows that there is a high rate of readmission within one year, namely 15.8%. The most common conditions among readmitted patients are hypertension (38.6%), ischemic heart disease (16.9%), and diabetes mellitus (16.6%). An extensive multivariable study revealed that age, gender, and particular comorbidities such as malnutrition and hyperlipidemia are important factors that can significantly predict greater readmission rates, longer hospital stays or increased healthcare costs. The multivariable models show a moderate to good ability to predict patient outcomes, with concordance index ranging from 0.701 to 0.752. This suggests that targeted interventions in these areas could improve patient outcomes and make better use of healthcare resources.

CONCLUSIONS

The results regarding the association between severe exacerbations and systemic disease status support the integration of systematic evaluation of comorbidities into the management of exacerbations and the intensification of treatment of important comorbidities as a appropriate measure for prevention of further exacerbations. Our models also provide a novel tool for clinicians to determine the risk of the 1-year recurrence of severe ECOPD in hospitalised patients.

New-Onset Atrial Fibrillation Is a Risk Factor of Ischemic Stroke in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) induces atrial fibrillation (AF) and stroke, and COPD with AF increased ischemic stroke (IS) in a cross-sectional study. Therefore, healthcare providers must be concerned and well-informed about this particular situation. For this study, inpatient data were obtained from the Taiwan National Health Insurance Database in 2010. We identified patients who were hospitalized with COPD (International Classification of Disease, Ninth Revision, Clinical Modification [ICD-9-CM] is 491, 492, and 496). Patients who experienced AF (ICD-9-CM to 427.3) during the same admission or after COPD hospitalization were discharged and defined as new-onset AF. The outcome was IS (ICD-9-CM as 433–437). The factors related to IS after COPD were used for multivariate logistic regression. There were 4177/62163 (6.72%) patients with incident IS. The risk of IS after COPD hospitalization was shown to have an adjusted odds ratio of 1.749 (95% CI: 1.584–1.93, p < 0.001) for patients with new-onset AF. Other factors included advanced age, atherosclerosis factors, comorbidity severity, sepsis and lower-level hospital admission. In conclusion, COPD patients suffering from new-onset AF had an increased incidence of IS in the population observation study. New-onset AF was an omit risk factor for IS in COPD in the Chinese population.

Characterization and Triggers of Dyspnea in Patients with Chronic Obstructive Pulmonary Disease or Chronic Heart Failure: Effects of Weather and Environment

BACKGROUND AND OBJECTIVES

Dyspnea is one of the most disturbing symptoms for patients with chronic obstructive pulmonary disease (COPD) or heart failure (HF). This study investigated dyspnea triggers and factors associated with worsening dyspnea in patients with COPD or HF.

METHODS

COPD support group members and HF patients with reduced ejection fraction (HFrEF) and no airway obstruction answered a questionnaire describing different weather conditions (rising/falling air pressure, sunny, foggy, rainy, windy, snowy, hazy, high ozone levels, and airborne pollen) and environmental circumstances (cooking, grilling, perfumes, cigarette smoke, gasoline odor, and flower scents) and were asked to estimate the occurrence and severity of dyspnea under these conditions using predefined scales.

RESULTS

230 patients with COPD and 90 with HFrEF (left ventricular ejection fraction 34 ± 10%, Tiffeneau index > 70%) were analyzed. COPD patients reported dyspnea more often than HF patients in almost all weather and environmental conditions (p = 0.004 to p < 0.001), with the exception of outdoor floral scents and cigarette smoke. Severe to very severe dyspnea was reported more in COPD versus HF in all weather and environmental conditions except sunny weather (p = 0.01 to p < 0.001). COPD was associated with more severe dyspnea than HF in all conditions (all p < 0.001).

CONCLUSIONS

Dyspnea was triggered by a variety of weather and other environmental triggers in patients with COPD and occurred more often than in HF patients under the same conditions. Foggy weather and exposure to perfumes were associated with severe dyspnea in the majority of COPD patients, but only a minority of HF patients.

Expansion of a Population of Large Monocytes (Atypical Monocytes) in Peripheral Blood of Patients with Acute Exacerbations of Chronic Obstructive Pulmonary Diseases

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is closely associated with airway inflammation including monocytes, lymphocytes, and neutrophils. Monocytes play an essential role in the pathogenesis of chronic obstructive pulmonary disease (COPD). To elucidate the association of circulating monocyte alteration with AECOPD, we analyzed monocyte subpopulation in the peripheral blood of 16 healthy volunteers and 22 AECOPD patients at the stages of admission and remission after clinical therapy. We found a dramatic increase of a previously unreported population of large size circulating atypical monocytes (A Mo) in AECOPD patients, characterized by higher forward scatter and lower side scatter values than the typical monocytes (T Mo) which were observed predominantly in healthy individuals. Further analysis showed that A Mo expressed higher levels of CD16, intercellular adhesion molecule 1 (ICAM-1), and chemotactic protein-1 receptor-2 (CCR2) than T Mo. In contrast, the expression of class II antigen (HLA-DR) by A Mo was lower than T Mo. More importantly, we observed that the percentage of circulating A Mo among total monocytes correlated with the length of hospital stay (time to remission) and disease duration. The data suggest that circulating A Mo might have the potential to serve as a biomarker in the diagnosis and prognosis of AECOPD.

Epidemiology and impact of chronic bronchitis in chronic obstructive pulmonary disease

Research on the association between chronic bronchitis and chronic obstructive pulmonary disease (COPD) exacerbations has led to discordant results. Furthermore, the impact of chronic bronchitis on mortality in COPD subjects is unclear.Within the Rotterdam Study, a population-based cohort study of subjects aged ≥45 years, chronic bronchitis was defined as having a productive cough for ≥3 months per year for two consecutive years. Linear, logistic regression and Cox proportional hazard models were adjusted for age, sex and pack-years.Out of 972 included COPD subjects, 752 had no chronic phlegm production (CB-) and 220 had chronic phlegm production, of whom 172 met the definition of chronic bronchitis (CB+). CB+ subjects were older, more frequently current smokers and had more pack-years than CB- subjects. During a median 6.5 years of follow-up, CB+ subjects had greater decline in lung function (-38 mL·year-1, 95% CI -61.7--14.6; p=0.024). CB+ subjects had an increased risk of frequent exacerbations (OR 4.0, 95% CI 2.7-5.9; p<0.001). In females, survival was significantly worse in CB+ subjects compared to CB- subjects. Regarding cause-specific mortality, CB+ subjects had an increased risk of respiratory mortality (hazard ratio 2.16, 95% CI 1.12-4.17; p=0.002).COPD subjects with chronic bronchitis have an increased risk of exacerbations and respiratory mortality compared to COPD subjects without chronic phlegm production.

Exacerbation of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a disease with high prevalence and substantial associated economical burden. A significant determinant of quality of life, long-term survival, and health care costs is an acute exacerbation of COPD. Acute exacerbations are provoked by respiratory viruses, altered airway microbiome, and environmental factors. The current treatment options are limited. In order to develop specific therapeutic measures, it is important to understand how acute exacerbations evolve. This review focuses on pathophysiology of stable and exacerbated COPD.

Use of biologics to treat acute exacerbations and manage disease in asthma, COPD and IPF

A common feature of chronic respiratory disease is the progressive decline in lung function. The decline can be indolent, or it can be accelerated by acute exacerbations, whereby the patient experiences a pronounced worsening of disease symptoms. Moreover, acute exacerbations may also be a marker of insufficient disease management. The underlying cause of an acute exacerbation can be due to insults such as pathogens or environmental pollutants, or the cause can be unknown. For each acute exacerbation, the patient may require medical intervention such as rescue medication, or in more severe cases, hospitalization and ventilation and have an increased risk of death. Biologics, such as monoclonal antibodies, are being developed for chronic respiratory diseases including asthma, COPD and IPF. This therapeutic approach is particularly well suited for chronic use based on the route and frequency of delivery and importantly, the potential for disease modification. In recent clinical trials, the frequency of acute exacerbation has often been included as an endpoint, to help determine whether the investigational agent is impacting disease. Therefore the significance of acute exacerbations in driving disease, and their potential as a marker of disease activity and progression, has recently received much attention. There is also now a need to standardize the definition of an acute exacerbation in specific disease settings, particularly as this endpoint is increasingly used in clinical trials to also assess therapeutic efficacy. Moreover, specifically targeting exacerbations may offer a new therapeutic approach for several chronic respiratory diseases.

Upper respiratory symptoms worsen over time and relate to clinical phenotype in chronic obstructive pulmonary disease

RATIONALE

How nasal symptoms in patients with chronic obstructive pulmonary disease (COPD) change over time and resolve during naturally occurring exacerbations has not been described previously.

OBJECTIVES

To evaluate the evolution and impact of upper airway symptoms in a well-defined COPD cohort when stable and at exacerbation.

METHODS

Patients in the London COPD cohort were asked about the presence of nasal symptoms (nasal discharge, sneezing, postnasal drip, blocked nose, and anosmia) over an 8-year period (2005-2013) every 3 months at routine clinic visits while in a stable state and daily during exacerbations with the use of diary cards. Data were prospectively collected, and, in a subgroup of patients, COPD Assessment Test scores and human rhinovirus identification by polymerase chain reaction were available. Patients were also defined as having infrequent or frequent exacerbations (<2 or ≥2 exacerbations/yr, respectively).

MEASUREMENTS AND MAIN RESULTS

At an aggregate of 4,368 visits, 209 patients with COPD were asked about their nasal symptoms. At 2,033 visits when the patients were stable, the odds ratio (OR) for nasal discharge increased by 1.32% per year (95% confidence interval [CI], 1.19-1.45; P < 0.001); the OR for sneezing increased by 1.16% (95% CI, 1.05-1.29; P = 0.005); the OR for postnasal drip increased by 1.18% (95% CI, 1.03-1.36; P = 0.016); and the OR for anosmia increased by 1.19% (95% CI, 1.03-1.37; P = 0.015). At visits when the patients were having exacerbations, nasal discharge was present for 7 days and blocked nose, sneezing, and postnasal drip increased for just 3 days. Anosmia did not change. Nasal discharge was more likely in patients with frequent exacerbations (OR, 1.96; 95% CI, 1.17-3.28; P = 0.011), and COPD Assessment Test scores were higher by 1.06 units (95% CI, 0.32-1.80; P = 0.005) when patients were stable and higher by 1.30 units (95% CI, 0.05-2.57; P = 0.042) during exacerbations.

CONCLUSIONS

Upper airway symptoms increase over time in patients with COPD and are related to the frequent exacerbation phenotype. These longitudinal changes may be due to increasing airway inflammation or to progression of COPD.

Relationships of MMP-9 and TIMP-1 proteins with chronic obstructive pulmonary disease risk: A systematic review and meta-analysis

Background:

We performed this meta-analysis in order to collect all the relevant studies to clarify the correlations of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) with chronic obstructive pulmonary disease (COPD).

Materials and Methods:

After a literature search in electronic databases, pertinent case-control studies investigating the correlations of MMP-9 and TIMP-1 protein expressions within a COPD setting were enrolled based on our strict inclusion and exclusion criteria. We used key words such as “chronic obstructive pulmonary disease,” “COPD” or “COAD” or “chronic obstructive airway disease” and “matrix metalloproteinases” or “MMPs” to make a searching strategy in this study. STATA software (version 12.0, Stata Corporation, College Station, TX, USA) was utilized for statistical analysis.

Results:

A total of 20 studies were enrolled into this meta-analysis including 923 COPD patients and 641 healthy controls. The findings of this meta-analysis revealed that serum expression levels of MMP-9 and TIMP-1 protein in COPD patients were higher than those of healthy controls (MMP-9: SMD = 1.44, 95%CI = 0.85 ~ 2.04, P < 0.001; TIMP-1: SMD = 3.53, 95% CI = 2.31 ~ 4.75, P < 0.001). Subgroup analysis based on ethnicity revealed that both Caucasians and Asian COPD patients exhibited higher MMP-9 and TIMP-1 serum protein levels than healthy controls (MMP-9: SMD = 0.81, 95%CI = 0.15~1.48, P = 0.016; TIMP-1: SMD = 4.43, 95%CI = 1.98 ~ 6.87, P = 0.016) and in Caucasians (MMP-9: SMD = 2.30, 95%CI = 1.21 ~ 3.38, P < 0.001; TIMP-1: SMD = 2.86, 95%CI = 1.47 ~ 4.24, P < 0.001).

Conclusion:

The result of this meta-analysis indicates that elevated levels of MMP-9 and TIMP-1 proteins may be correlated with the pathogenesis of COPD, and the two proteins may represent important biological markers for the early diagnosis of COPD.

High glucose induces dysfunction of airway epithelial barrier through down-regulation of connexin 43

The airway epithelium is a barrier to the inhaled antigens and pathogens. Connexin 43 (Cx43) has been found to play critical role in maintaining the function of airway epithelial barrier and be involved in the pathogenesis of the diabetic retinal vasculature, diabetes nephropathy and diabetes skin. Hyperglycemia has been shown to be an independent risk factor for respiratory infections. We hypothesize that the down-regulation of Cx43 induced by HG alters the expression of tight junctions (zonula occludens-1 (ZO-1) and occludin) and contributes to dysfunction of airway epithelial barrier, and Cx43 plays a critical role in the process in human airway epithelial cells (16 HBE). We show that high glucose (HG) decreased the expression of ZO-1 and occludin, disassociated interaction between Cx43 and tight junctions, and then increased airway epithelial transepithelial electrical resistance (TER) and permeability by down-regulation of Cx43 in human airway epithelial cells. These observations demonstrate an important role for Cx43 in regulating HG-induced dysfunction of airway epithelial barrier. These findings may bring new insights into the molecular pathogenesis of pulmonary infection related to diabetes mellitus and lead to novel therapeutic intervention for the dysfunction of airway epithelial barrier in chronic inflammatory airway diseases.

Antibiotic Resistant and Virulence Determinants of Staphylococcus haemolyticus C10A as Revealed by Whole Genome Sequencing

Staphylococcus haemolyticus is one of the pathogens that harbor a high level of antibiotic resistance. Here, we highlighted the potential determinants for multidrug resistance and virulence from the draft genome of Staphylococcus haemolyticus strain C10A, isolated from a patient with chronic obstructive pulmonary disease exacerbation.

Prevention of Exacerbations in Chronic Obstructive Pulmonary Disease: Knowns and Unknowns

The 2011 recommendations of the Global initiative for chronic Obstructive Lung Disease (GOLD) constituted a major paradigm shift in COPD management since they set 2 major goals for the assessment and management of patients: (1) the reduction of their current level of symptoms (i.e., treat the patient today); and (2) the reduction of their risk of exacerbations (i.e., prevent them tomorrow). Exacerbations are not only an important clinical endpoint in patients with COPD, but they are also a risk factor themselves for additional adverse outcomes since they have been shown to increase the risk for mortality, to accelerate the decline in pulmonary function, and to decrease health status and quality of life. Despite their importance, many unanswered questions related to exacerbations remain. The purpose of this review is to discuss: (1)knowns and unknowns in our current understanding of exacerbations, (2) what known factors increase their risk, and (3) how to best prevent them.

Expert consensus on acute exacerbation of chronic obstructive pulmonary disease in the People's Republic of China

Chronic obstructive pulmonary disease (COPD) is a common disease that severely threatens human health. Acute exacerbation of COPD (AECOPD) is a major cause of disease progression and death, and causes huge medical expenditures. This consensus statement represents a description of clinical features of AECOPD in the People's Republic of China and a set of recommendations. It is intended to provide clinical guidelines for community physicians, pulmonologists and other health care providers for the prevention, diagnosis, and treatment of AECOPD.

Chronic disease burden among cancer survivors in the California Behavioral Risk Factor Surveillance System, 2009-2010

PURPOSE

The California Behavioral Risk Factor Surveillance System estimates that 56.6 % of cancer survivors report ever being diagnosed with a chronic disease. Few studies have assessed potential variability in comorbidity by cancer type.

METHODS

We used data collected from a representative sample of adult participants in the 2009 and 2010 California Behavioral Risk Factor Surveillance System (n = 18,807). Chronic diseases were examined with cancer survivorship in case/non-case and case/case analyses. Prevalence ratios (PR) and corresponding 95 % confidence intervals (95 % CI) were estimated using Cox proportional hazards models, with adjustment on race, sex, age, education, smoking, and drinking.

RESULTS

Obesity was associated with gynecological cancers (PR 1.74; 95 % CI 1.26-2.41), and being overweight was associated with gynecological (PR 1.40; 95 % CI 1.05-1.86) and urinary (PR 2.19; 95 % CI 1.21-3.95) cancers. Arthritis was associated with infection-related (PR 1.78; 95 % CI 1.12-2.83) and hormone-related (PR 1.20; 95 % CI 1.01-1.42) cancers. Asthma was associated with infection- (PR 2.26; 95 % CI 1.49-3.43), hormone- (PR 1.46; 95 % CI 1.21-1.77), and tobacco- (PR 1.86; 95 % CI 1.25-2.77) related cancers. Chronic obstructive pulmonary disease (COPD) was associated with infection- (PR 2.16; 95 % CI 1.22-3.83) and tobacco-related (PR 2.24; 95 % CI 1.37-3.66) cancers and with gynecological cancers (PR 1.60; 95 % 1.00-2.56).

CONCLUSIONS

This is the first study to examine chronic disease burden among cancer survivors in California. Our findings suggest that the chronic disease burden varies by cancer etiology.

IMPLICATIONS FOR CANCER SURVIVORS

A clear need has emerged for future biological and epidemiological studies of the interaction between chronic disease and cancer etiology in survivors.

Acute Exacerbation and Respiratory InfectionS in COPD (AERIS): protocol for a prospective, observational cohort study

INTRODUCTION

The aetiology of acute exacerbations of chronic obstructive pulmonary disease (COPD) remains incompletely understood and strategies for treatment and prevention have not altered significantly for many years. Improved understanding of the role of respiratory pathogens in acute exacerbations of COPD (AECOPD) is required and the use of molecular microbiological techniques may lead to insights into host-pathogen interactions and the development of more targeted therapeutic approaches.

METHODS AND ANALYSES

Acute Exacerbation and Respiratory InfectionS in COPD (AERIS) is a longitudinal epidemiological study to assess how changes in the COPD airway microbiome contribute to the incidence and severity of AECOPD. Patients with COPD aged 40-85 are followed monthly for 2 years, and reviewed within 72 h of onset of symptoms of AECOPD. Exacerbations are detected using daily electronic diary cards. Blood, sputum, nasopharyngeal and urine samples are collected at prespecified timepoints. Molecular diagnostic and typing techniques are used to describe the dynamics of airway infection during AECOPD and stable disease, and associations with clinical outcome. This study aims to refine the case definition of AECOPD to reflect the possible microbiological aetiology. AERIS will assess the impact of AECOPD on health-related quality of life and healthcare resource utilisation, and the possible interactions between nutritional status, infection and immune responses.

ETHICS AND DISSEMINATION

AERIS is conducted in accordance with the Declaration of Helsinki and Good Clinical Practice, and has been approved by the institutional ethics and review board. All participants must provide written informed consent. The results obtained will be disseminated at international medical conferences and in peer-reviewed publications.

DISCUSSION

Few other studies have addressed the complexity of the microbiological and systemic components of COPD or employed real-time electronic tracking of symptoms to identify AECOPD and potential aetiological triggers.

RESULTS

Results of AERIS will increase our understanding of the contribution of pathogens to AECOPD, potentially leading to new targeted therapeutic and preventative interventions.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01360398.

Classification of exacerbation episodes in chronic obstructive pulmonary disease patients

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive disease affecting the airways, which constitutes a major cause of chronic morbidity and a significant economic and social burden throughout the world. Despite the fact that in COPD patients exacerbations are common acute events causing significant and often fatal worsening of symptoms, an accurate prognostication continues to be difficult.

OBJECTIVES

To build computational models capable of distinguishing between normal life days from exacerbation days in COPD patients, based on physical activity measured by accelerometers.

METHODS

We recruited 58 patients suffering from COPD and measured their physical activity with accelerometers for 10 days or more, from August 2009 to March 2010. During this period we recorded six exacerbation episodes in the patients, accounting for 37 days. We were able to analyse data for 52 patients (369 patient days), and extracted three distinct sets of features from the data, one set of basic features such as average, one set based on the frequency domain and the last exploring the cross-information among sensors pairs. These were used by three machine-learning techniques (logarithmic regression, neural networks, support vector machines) to distinguish days with exacerbation events from normal days.

RESULTS

The support vector machine classifier achieved an AUC of 90% ± 9, when supplied with a set of features resulting from sequential feature selection method. Neu- ral networks achieved an AUC of 83% ± 16 and the logarithmic regression an AUC of 67% ± 15.

CONCLUSIONS

None of the individual feature sets provided robust for reasonable classification of PA recording days. Our results indicate that this approach has the potential to extract useful information for, but are not robust enough for medical application of the system.

Mechanisms of acute exacerbation of respiratory symptoms in chronic obstructive pulmonary disease

Exacerbations of chronic obstructive respiratory disease (ECOPD) are acute events characterized by worsening of the patient's respiratory symptoms, particularly dyspnoea, leading to change in medical treatment and/or hospitalisation. AECOP are considered respiratory diseases, with reference to the respiratory nature of symptoms and to the involvement of airways and lung. Indeed respiratory infections and/or air pollution are the main causes of ECOPD. They cause an acute inflammation of the airways and the lung on top of the chronic inflammation that is associated with COPD. This acute inflammation is responsible of the development of acute respiratory symptoms (in these cases the term ECOPD is appropriate). However, the acute inflammation caused by infections/pollutants is almost associated with systemic inflammation, that may cause acute respiratory symptoms through decompensation of concomitant chronic diseases (eg acute heart failure, thromboembolism, etc) almost invariably associated with COPD. Most concomitant chronic diseases share with COPD not only the underlying chronic inflammation of the target organs (i.e. lungs, myocardium, vessels, adipose tissue), but also clinical manifestations like fatigue and dyspnoea. For this reason, in patients with multi-morbidity (eg COPD with chronic heart failure and hypertension, etc), the exacerbation of respiratory symptoms may be particularly difficult to investigate, as it may be caused by exacerbation of COPD and/or ≥ comorbidity, (e.g. decompensated heart failure, arrhythmias, thromboembolisms) without necessarily involving the airways and lung. In these cases the term ECOPD is inappropriate and misleading.