Contribution of the environment and comorbidities to chronic obstructive pulmonary disease phenotypes

Exploring the silent connection: unveiling the intricate relationship between gastroesophageal reflux disease and sleep apnea syndrome

BACKGROUND

Gastroesophageal reflux disease (GERD) and Sleep Apnea Syndrome (SAS) are two prevalent medical conditions that significantly affect health and quality of life. GERD involves stomach content reflux into the esophagus, while SAS causes recurrent upper airway obstruction during sleep. Despite recent studies hinting at a link, the precise relationship and causality between GERD and SAS remain unclear. Our research uses bidirectional Mendelian randomization to explore this intricate relationship. Additionally, given SAS's high prevalence in cardiovascular patients (40-80%, as highlighted by the American Heart Association), we also investigated its potential association with various cardiovascular diseases to gain new insights into prevention and treatment.

METHODS

This study employed genetic data from large-scale genome-wide association studies (GWAS) on GERD (129,080 cases, 473,524 controls) and SAS (25,008 cases, 391,473 controls) for two-sample Mendelian randomization (MR) analysis to estimate the causal effects of GERD on the risk of SAS. All SNPs were selected using a strict clump window (r2 = 0.001 and kb = 10,000). We initially applied the inverse variance weighted (IVW) method and measured horizontal pleiotropy using MR-Egger, weighted median, and weighted mode methods. I2 index and Cochran Q statistics were used for sensitivity analysis. Funnel plot symmetry of IVW MR estimates versus 1/standard error (1/SEIV) was examined to exclude SNPs potentially causing heterogeneity. Additionally, to exclude reverse causality, bidirectional MR was employed to investigate whether genetic susceptibility to SAS causally influenced the risk of GERD.

RESULTS

GERD was associated with an elevated risk of SAS, demonstrating an odds ratio (OR) of 1.750 (95% CI 1.590-1.930; P < 0.001). Conversely, there was no compelling evidence to indicate a causal link between SAS and the risk of developing GERD, with an OR of 1.000 (95% CI 0.989-1.011; P = 0.964). In addition to the primary findings, our study also revealed significant risks associated with SAS for several cardiovascular conditions, including coronary heart disease, atrial fibrillation, coronary artery disease, heart failure, intracerebral hemorrhage, and ischemic stroke.

CONCLUSION

We discovered compelling evidence indicating an elevated risk of SAS in individuals with GERD, but no significant evidence supporting an increased risk of GERD in those with SAS. Future investigations into SAS risk should take into account the potential therapeutic targeting of GERD. PPI and histamine antagonists can effectively reduce reflux and airway secretions, preventing airway damage and collapse. Furthermore, it is necessary to investigate the underlying mechanisms by which GERD affects SAS. For example, the inflammatory stimulation caused by gastric acid and pepsin in refluxed fluid, as well as the increased tension of bronchial smooth muscle caused by vagus nerve reflex. Thus, early preventive measures can be implemented for potential complications related to SAS.

Risk of Cardiovascular Events Associated with Chronic Obstructive Pulmonary Disease and/or Metabolic Syndrome: A Large-Scale Nationwide Population-Based Cohort Study

Purpose

Chronic obstructive pulmonary disease (COPD) and metabolic syndrome (MetS) are among the most prevalent conditions that might predispose individuals to life-threatening events. We aimed to examine their associations with cardiovascular (CV) events and mortality using a large-scale population dataset from the National Health Information Database in Korea.

Patients and Methods

This population-based cohort study enrolled adults aged ≥40 years who had undergone more than two health examinations between 2009 and 2011. They were divided into four groups based on the presence of COPD and MetS. Analysis of the outcomes and CV events or deaths was performed from 2014 to 2019. We compared CV event incidence and mortality rates using a multivariate Cox proportional hazards model and Kaplan-Meier curves.

Results

Totally, 5,101,810 individuals were included, among whom 3,738,458 (73.3%) had neither COPD nor MetS, 1,193,014 (23.4%) had only MetS, 125,976 (2.5%) had only COPD, and 44,362 (0.9%) had both. The risk of CV events was significantly higher in individuals with both COPD and MetS than in those with either COPD or MetS alone (HRs: 2.4 vs 1.6 and 1.8, respectively; all P <0.001). Similarly, among those with both COPD and MetS, all-cause and CV mortality risks were also elevated (HRs, 2.9 and 3.0, respectively) compared to the risks in those with either COPD (HRs, 2.6 and 2.1, respectively) or MetS (HRs, 1.7 and 2.1, respectively; all P <0.001).

Conclusion

The comorbidity of MetS in patients with COPD increases the incidence of CV events and all-cause and cardiovascular mortality rates.

SIRT1 as a Potential Therapeutic Target for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common, preventable, and treatable disease characterized by irreversible airflow obstruction and lung function decline. It is well established that COPD represents a major cause of morbidity and mortality globally. Due to the substantial economic and social burdens associated with COPD, it is necessary to discover new targets and develop novel beneficial therapies. Although the pathogenesis of COPD is complex and remains to be robustly elucidated, numerous studies have shown that oxidative stress, inflammatory responses, cell apoptosis, autophagy, and aging are involved in the pathogenesis of COPD. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase belonging to the silent information regulator 2 (Sir2) family. Multiple studies have indicated that SIRT1 plays an important role in oxidative stress, apoptosis, inflammation, autophagy, and cellular senescence, which contributes to the pathogenesis and development of COPD. This review aimed to discuss the functions and mechanisms of SIRT1 in the progression of COPD and concluded that SIRT1 activation might be a potential therapeutic strategy for COPD.

New-onset atrial fibrillation in critically ill patients with coronavirus disease 2019 (COVID-19)

Background

Mortality in critically ill patients with coronavirus disease 2019 (COVID-19) is high, therefore, it is essential to evaluate the independent effect of new-onset atrial fibrillation (NOAF) on mortality in patients with COVID-19. We aimed to determine the incidence, risk factors, and outcomes of NOAF in a cohort of critically ill patients with COVID-19.

Methods

We conducted a retrospective study on patients admitted to the intensive care unit (ICU) with a diagnosis of COVID-19. NOAF was defined as atrial fibrillation that was detected after diagnosis of COVID-19 without a prior history. The primary outcome of the study was the effect of NOAF on mortality in critically ill COVID-19 patients.

Results

NOAF incidence was 14.9% (n = 37), and 78% of patients (n = 29) were men in NOAF positive group. Median age of the NOAF group was 79.0 (interquartile range, 71.5-84.0). Hospital mortality was higher in the NOAF group (87% vs 67%, respectively, P = .019). However, in multivariate analysis, NOAF was not an independent risk factor for hospital mortality (OR 1.42, 95% CI 0.40-5.09, P = .582).

Conclusions

The incidence of NOAF was 14.9% in critically ill COVID-19 patients. Hospital mortality was higher in the NOAF group. However, NOAF was not an independent risk factor for hospital mortality in patients with COVID-19.

Analysis of prevalence and prognosis of type 2 diabetes mellitus in patients with acute exacerbation of COPD

BACKGROUND

For patients with acute exacerbation of COPD (AECOPD), type 2 diabetes mellitus (T2DM) as comorbidity have poor outcomes. However, data on the impact of previously diagnosed and new- diagnosed T2DM in such a patient population is lacking.

METHODS

Inpatients diagnosed with AECOPD in the department of Pulmonary and Critical Care Medicine of The First Hospital of China Medical University during 2011-2017 were enrolled. Data on demography, prevalence of type 2 DM, other comorbidities, hospital stays and laboratory tests (including arterial partial pressure of oxygen [PaO2]) results were recorded. Results were compared with AECOPD patients having previously diagnosed and new-diagnosed type 2 diabetes. Markers associated with development of type 2 DM and the prognosis of AECOPD patients were identified.

RESULTS

Of the 196 patients enrolled in this study, the overall prevalence of T2DM was 26%. The PaO2 in the newly diagnosed T2DM group was considerably lower versus non-diabetic group. The T2DM group had a longer hospital stay and higher troponin level versus the non-diabetic group. AECOPD patients with T2DM were found to be correlated with hypertension. Age, need for assisted ventilation, increased troponin, and elevated fasting blood glucose on admission were risk factors for death in hospitalized AECOPD patients.

CONCLUSIONS

AECOPD patients had a higher prevalence of T2DM than the general population; T2DM comorbidity caused lower PaO2, longer hospital stays, and increased troponin. Poor blood glucose control may increase the risk of death in AECOPD patients.

Management of cardiovascular comorbidities in chronic obstructive pulmonary disease patients

Chronic obstructive pulmonary disease (COPD) is а highly prevalent, complex and heterogeneous clinical condition which is associated with significant concomitant diseases. COPD and cardiovascular diseases (CVDs) often coexist due to the high prevalence of each of these pathological conditions separately as well as the common risk factors (particularly smoking), mechanisms of interaction and influence of systemic inflammation. In addition, decreased pulmonary function in COPD is closely associated with an increased risk of congestive CVDs. One of the most important pathophysiological markers of COPD—lung hyperinflation—plays a significant role in the appearance of functional limitations of the pumping function of the heart, creating unfavorable conditions by exerting a compression effect on the heart muscle. The latter was confirmed by significant correlation between the COPD severity according to GOLD classification and the basic dimensions of the heart chambers. Several decades ago, the term “microcardia” was commonly used and indicated a radiological sign of emphysema. Some studies demonstrated a close relationship between the chance of occurrence of CVD and the severity of pulmonary dysfunction. Such an association has been demonstrated for the whole spectrum of CVD—including cerebrovascular disease, congestive heart failure (CHF) and rhythm disturbances—and was detected in the early stages of the disease. A large proportion of patients with mild and moderate COPD die due to CVD, which is much more likely than deaths in the same group due to respiratory insufficiency. COPD patients have a higher rate of hospitalization and death, the cause of which are coronary heart disease (CHD), stroke and CHF. Treatment of COPD today is mainly determined by national and international clinical guidelines, which should pay more attention to the problems of the treatment of COPD patients with comorbid conditions.

[Chronic obstructive pulmonary disease and cardiovascular comorbidity]

In recent years, a greater understanding of the heterogeneity and complexity of chronic obstructive pulmonary disease (COPD) has come from the point of view of an integrated clinical assessment of severity, pathophysiology, and the relationship with other pathologies. A typical COPD patient suffers on average 4 or more concomitant diseases and every day about a third of patients take from 5 to 10 different drugs. The mechanisms of the interaction of COPD and cardiovascular disease (CVD) include the effects of systemic inflammation, hyperinflation (hyperinflation) of the lungs and bronchial obstruction. The risk of developing CVD in patients with COPD is on average 2-3 times higher than in people of a comparable age in the general population, even taking into account the risk of smoking. The prevalence of coronary heart disease, heart failure, and rhythm disturbances among COPD patients is significantly higher than in the general population. The article discusses in detail the safety of prescribing various groups of drugs for the treatment of CVD in patients with COPD. Achieving success in understanding and managing patients with COPD and CVD is possible using an integrated multidisciplinary approach.

Ursolic Acid Protected Lung of Rats From Damage Induced by Cigarette Smoke Extract

Background: We found previously that ursolic acid (UA) administration could alleviate cigarette smoke-induced emphysema in rats partly through the unfolded protein response (UPR) PERK-CHOP and Nrf2 pathways, thus alleviating endoplasmic reticulum stress (ERS)-associated oxidative stress and cell apoptosis. We hypothesized that other UPR pathways may play similar roles in cigarette smoke extract (CSE)-induced emphysema. So, we sought to investigate the dynamic changes and effects of UPR and the downstream apoptotic pathways. Further, we investigated whether UA could alleviate CSE-induced emphysema and airway remodelling in rats, whether and when it exerts its effects through UPR pathways as well as Smads pathways.

Methods: One hundred eight Sprague Dawley (SD) rats were randomly divided into three groups: Sham group, CSE group, and UA group, and each group was further divided into three subgroups, administered CSE (vehicle) for 2, 3, or 4 weeks; each subgroup had 12 rats. We examined pathological changes, analyzed the three UPR signaling pathways and subsequent ERS, intrinsic and extrinsic apoptotic pathway indicators, as well as activation of Smad2,3 molecules in rat lungs.

Results: Exposure to CSE for 3 or 4 weeks could apparently induce emphysema and airway remodeling in rats, including gross and microscopic changes, alteration of mean alveolar number (MAN), mean linear intercept (MLI), and mean airway thickness in lung tissue sections. UA intervention could significantly alleviate CSE-induced emphysema and airway remodeling in rats. UA exerted its effects through ameliorating apoptosis by down regulating UPR signalling pathways and subsequent apoptosis pathways, as well as, downregulating p-Smad2 and p-Smad3 molecules.

Conclusions: UA attenuated CSE-induced emphysema and airway remodeling, exerting its effects partly through regulation of three UPR pathways, amelioration downstream apoptotic pathways, and alleviating activation of Smad2 and Smad3.

GDF-15 plasma levels in chronic obstructive pulmonary disease are associated with subclinical coronary artery disease

BACKGROUND

Growth differentiation factor-15 (GDF-15), a cytokine associated with cardiovascular mortality, increases during chronic obstructive pulmonary disease (COPD) exacerbations, but any role in stable COPD is unknown. We tested associations between GDF-15 and subclinical coronary atherosclerosis, assessed by coronary artery calcium (CAC) score, in COPD subjects free of clinical cardiovascular disease (CVD).

METHODS

Cross-sectional analysis of COPD participants (GOLD stages 2-4) in the COPDGene cohort without CVD at enrollment, using baseline CAC (from non-EKG-gated chest computed tomography) and plasma GDF-15 (by custom ELISA). We used multinomial logistic modeling of GDF-15 associations with CAC, adjusting for demographics, baseline risk (calculated using the HEART: Personal Heart Early Assessment Risk Tool (Budoff et al. 114:1761-1791, 2006) score), smoking history, measures of airflow obstruction, emphysema and airway disease severity.

RESULTS

Among 694 participants with COPD (47% women, mean age 63.6 years) mean GDF-15 was 1,304 pg/mL, and mean CAC score was 198. Relative to the lower GDF-15 tertile, higher tertiles showed bivariate association with increasing CAC score (mid tertile odds ratio [OR] 1.80, 95% confidence interval [CI] 1.29, 2.51; higher tertile OR 2.86, CI 2.04, 4.02). This association was maintained after additionally adjusting for baseline CVD risk, for co-morbidities and descriptors of COPD severity and impact, markers of cardiac stress (N-terminal pro-B-type natriuretic peptide, troponin T) and of inflammation (Interleukin-6), and in subgroup analysis excluding men, diabetics, current smokers or those with limited ambulation.

CONCLUSIONS

In ever-smokers with COPD free of clinical CVD, GDF-15 contributes independently to subclinical coronary atherosclerosis.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00608764 . Registered 28 January 2008.

Chronic obstructive pulmonary disease comorbidities

PURPOSE OF REVIEW

Classic descriptions of chronic obstructive pulmonary disease (COPD) centered on its impact on respiratory function. It is currently recognized that comorbidities contribute to the severity of symptoms and COPD progression. Understanding COPD-comorbidities associations could provide innovative treatment strategies and identify new mechanistic pathways to be targeted.

RECENT FINDINGS

Some comorbidities are clustered with specific COPD phenotypes. There are stronger associations between airway-predominant disease and cardio-metabolic comorbidities, whereas in emphysema-predominant COPD sarcopenia and osteoporosis are frequent. These patterns suggest different inflammatory pathways acting by COPD phenotype. Osteoporosis is a major concern in COPD, particularly among men. Although β-blockers use for cardiac indications in COPD remains low, recent evidence suggests that this medication group could decrease COPD exacerbations. Gastroesophageal reflux is consistently associated with poor COPD outcomes, but mechanisms and impact of treatment are still unclear. Nontraditional comorbid conditions, such as cognitive impairment, anxiety, and depression have significant impact in COPD outcomes.

SUMMARY

Clinicians should screen their COPD patients for the presence of cardiovascular disease, diabetes, osteoporosis, sleep apnea, and sarcopenia, comorbidities for which specific treatments are available and associated with better COPD outcomes. The impact of interventions to treat gastroesophageal reflux disease, anxiety and depression is still to be defined.

Gastroesophageal reflux disease symptoms in the Greek general population: prevalence and risk factors

Background and aims

Population-based data regarding the prevalence of gastroesophageal reflux disease (GERD) in Greece are very poor. This study estimated the prevalence of GERD symptoms and their risk factors in the Greek adult population.

Methods

A self-administered questionnaire was answered by a randomly selected population of 340 subjects. The question regarding “heartburn, chest pain, indigestion, or stomach acid coming up” as included in the Reflux Symptom Index was used for prevalence assessment.

Results

The monthly prevalence of GERD symptoms was found to be 52.0% in the Greek general population, with no statistically significant difference between the two sexes (P>0.05). The age group of 65–79 years showed a higher prevalence rate of GERD. Symptom severity was found to be mild (59.3%) or moderate (27.1%). The number of cigarettes smoked daily (but not smoking duration) as well as the number of alcoholic drinks consumed daily (but not the duration of alcohol drinking) were found to be related to GERD symptoms. No reported concomitant disease or medication was found to be related with GERD symptoms.

Conclusion

The prevalence of GERD symptoms in the Greek general population was found to be 52.0%. Tobacco smoking and alcohol drinking but not concomitant disease or medications were found to be related with GERD symptoms.

Understanding COPD: A vision on phenotypes, comorbidities and treatment approach

Chronic Obstructive Pulmonary Disease (COPD) phenotypes have become increasingly recognized as important for grouping patients with similar presentation and/or behavior, within the heterogeneity of the disease. The primary aim of identifying phenotypes is to provide patients with the best health care possible, tailoring the therapeutic approach to each patient. However, the identification of specific phenotypes has been hindered by several factors such as which specific attributes are relevant, which discriminant features should be used for assigning patients to specific phenotypes, and how relevant are they to the therapeutic approach, prognostic and clinical outcome. Moreover, the definition of phenotype is still not consensual. Comorbidities, risk factors, modifiable risk factors and disease severity, although not phenotypes, have impact across all COPD phenotypes. Although there are some identified phenotypes that are fairly consensual, many others have been proposed, but currently lack validation. The on-going debate about which instruments and tests should be used in the identification and definition of phenotypes has contributed to this uncertainty. In this paper, the authors review present knowledge regarding COPD phenotyping, discuss the role of phenotypes and comorbidities on the severity of COPD, propose new phenotypes and suggest a phenotype-based pharmacological therapeutic approach. The authors conclude that a patient-tailored treatment approach, which takes into account each patient's specific attributes and specificities, should be pursued.

Socioeconomic Characteristics Are Major Contributors to Ethnic Differences in Health Status in Obstructive Lung Disease: An Analysis of the National Health and Nutrition Examination Survey 2007-2010

BACKGROUND

Understanding ethnic differences in health status (HS) could help in designing culturally appropriate interventions. We hypothesized that racial and ethnic differences exist in HS between non-Hispanic whites and Mexican Americans with obstructive lung disease (OLD) and that these differences are mediated by socioeconomic factors.

METHODS

We analyzed 826 US adults aged ≥ 30 years self-identified as Mexican American or non-Hispanic white with spirometry-confirmed OLD (FEV₁/FVC < 0.7) who participated in the National Health and Nutrition Examination Survey 2007-2010. We assessed associations between Mexican American ethnicity and self-reported HS using logistic regression models adjusted for demographics, smoking status, number of comorbidities, limitations for work, and lung function and tested the contribution of education and health-care access to ethnic differences in HS.

RESULTS

Among Mexican Americans with OLD, worse (fair or poor) HS was more prevalent than among non-Hispanic whites (weighted percentage [SE], 46.6% [5.0] vs 15.2% [1.6]; P < .001). In bivariate analysis, socioeconomic characteristics were associated with lower odds of reporting poor HS (high school graduation: OR, 0.24 [95% CI, 0.10-0.40]; access to health care: OR, 0.50 [95% CI, 0.30-0.80]). In fully adjusted models, a strong association was found between Mexican American ethnicity (vs non-Hispanic white) and fair or poor HS (OR, 7.52; 95% CI, 4.43-12.78; P < .001). Higher education and access to health care contributed to lowering the Mexican American ethnicity odds of fair or poor HS by 47% and 16%, respectively, and together, they contributed 55% to reducing the differences in HS with non-Hispanic whites.

CONCLUSIONS

Mexican Americans with OLD report poorer overall HS than non-Hispanic whites, and education and access to health care are large contributors to the difference.

Implications of the GOLD COPD Classification and Guidelines

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines classification is based on the combination of patient risk and the severity of their symptoms.

The RESPECT study: RESearch on the PrEvalence and the diagnosis of COPD and its Tobacco-related etiology: a study protocol

BACKGROUND

Smoking remains a leading health risk factor among Europeans. Tobacco, together with other factors, will lead to an expansive epidemic of chronic diseases, including COPD, among the working population in Russia. The general aim of the RESearch on the PrEvalence and the diagnosis of COPD and its Tobacco-related etiology (RESPECT) study is to gain a better understanding of the prevalence, pathogenesis and symptoms of COPD.

METHODS/DESIGN

The RESPECT study is a prospective, population-based cohort study of subjects aged 35-70 years in two north-west regions of the Russian Federation (Saint Petersburg and Arkhangelsk). The study includes three components: a cross-sectional study (prevalence), a case-control study and a cohort study (diagnostic). An investigator who interviewed the patient completed three questionnaires. Spirometry, including a reversibility test, was offered to all participants. Individuals displaying forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 0.7 and/or FEV1/FVC < the lower limit of normal before and/or after bronchodilation were included in a follow-up study and were examined by a pulmonologist using a standardized comprehensive examination protocol. A future case-control study of two matched groups of patients (heavy smokers with COPD versus heavy smokers without COPD) will provide information on which factors (biomarkers, including pneumoproteins, in serum and induced sputum) are related to tobacco-induced COPD.

DISCUSSION

In total, 3133 individuals (2122 from St. Petersburg and 1012 from Arkhangelsk) aged 35-70 years agreed to participate in this study and met the inclusion criteria. In total, 2974 participants met the quality criteria for spirometry, and 2388 reversibility tests were performed. A cohort of newly defined obstructive pulmonary disease patients (247 persons) was established for follow-up investigation. The RESPECT study will provide information regarding the prevalence of COPD in the north-west region of the Russian Federation. Moreover, the comprehensive RESPECT database will enable us to explore new research questions, provide novel insight into the risk factors and different phenotypes of COPD, and contribute to an improved understanding of the reasons why some heavy smokers develop the disease whereas others do not.

CLINICAL TRIAL REGISTRATION

NCT02307799 (the release date: 12/01/2014).

Chronic obstructive pulmonary disease and cerebrovascular disease: A comprehensive review

Along with the aging population, the public health burden of cerebrovascular disease is increasing. Cerebral small vessel disease and accumulation of brain pathology associate with cognitive decline and can lead to clinical outcomes, such as stroke and dementia. Chronic Obstructive Pulmonary Disease (COPD) is a common respiratory disease among elderly. The quality of life and prognosis of patients with COPD is greatly determined by the presence of comorbidities including stroke and cognitive impairment. Despite the clinical relevance of cerebral small vessel disease, stroke and (vascular) cognitive impairment in patients with COPD, literature is scarce and underlying mechanisms are unknown. The aim of the present review is therefore to summarize current scientific knowledge, to provide a better understanding of the interplay between COPD and the aging brain and to define remaining knowledge gaps. This narrative review article 1) overviews the epidemiology of cerebral small vessel disease, stroke and cognitive impairment in patients with COPD; 2) discusses potential underlying mechanisms including aging, smoking, systemic inflammation, vasculopathy, hypoxia and genetic susceptibility; and 3) highlights areas requiring further research.

Chronic obstructive pulmonary disease, cognitive impairment, and development of disability: the health and retirement study

RATIONALE

The relationship between chronic obstructive pulmonary disease (COPD) and cognitive impairment in leading to disability has not been characterized.

OBJECTIVES

We aimed to investigate the prevalence and cumulative incidence of disability among adults with and without COPD and the association of COPD and cognitive impairment with disability.

METHODS

We analyzed 2006-2008 waves of the Health and Retirement Study, a nationally representative longitudinal health survey. COPD was self-reported. Prevalent disability was defined as baseline dependency in one or more activities of daily living (ADLs) and incident disability as one or more additional ADL dependencies. We used a validated performance-based measure of cognition to identify dementia and mild cognitive impairment. Covariates included seven chronic diseases, four geriatric syndromes, and sociodemographics. We used logistic regression to test associations between COPD, cognitive status, and prevalent/incident disability.

MEASUREMENTS AND MAIN RESULTS

Of 17,535 participants at least 53 years of age in wave 2006 (representing 77.7 million Americans), 9.5% reported COPD and 13.5% mild cognitive impairment; 17.5% of those with COPD had mild cognitive impairment. Prevalent disability for COPD was 12.8% (5.2% for no-COPD, P < 0.001). An additional 9.2% with COPD developed incident disability at 2 years (4.0% for no-COPD, P < 0.001). In adjusted models, COPD was associated with baseline (odds ratio, 2.0) and incident disability (odds ratio, 2.1; adjusted for baseline disability). Cognitive impairment had an additive effect to COPD. The COPD-disability association, prevalent/incident, was of similar or greater magnitude than that of other chronic diseases (e.g., stroke, diabetes). The associations were maintained in sensitivity analyses using alternative definitions of disability (dependency in two or more ADLs, dependency in instrumental ADLs), and in analysis excluding respondents with dementia.

CONCLUSIONS

Both COPD and mild cognitive impairment increase the risk of disability. The risk conferred by COPD is significant and similar or higher than other chronic diseases.

Effects of therapies for regulating and reinforcing lung and kidney on osteoporosis in rats with chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the efficacy and long-term effects of the three therapies for regulating and reinforcing lung and kidney (reinforcing lung and invigorating spleen, reinforcing lung and replenishing kidney, and supplementing Qi and nourishing kidney) in Traditional Chinese Medicine (TCM) on osteoporosis in rats with chronic obstructive pulmonary disease.

METHODS

Totally 120 rats were randomly divided into control, model, Bufeijianpi, Bufeiyishen, Yiqizishen, aminophyline groups. Repeated smoke inhalations and bacterial infections were used to duplicate the stable Chronic obstructive pulmonary disease rat model. Normal saline was given to the air control and model groups, while Bufeijianpi granule, Bufeiyishen granule, and Yiqizishen granule, and aminophylline were administrated to rats in the Bufeijianpi, Bufeiyishen, Yiqizishen, and aminophylline groups respectively from weeks 9 through 20. Another 12 weeks without medicines to observe the long-term effect. Rats were sacrificed at week 20 and week 32. Bone mass density (BMD), bone mineral content (BMC), morphology of the femoral head, lung function, and levels of serum interleukin (IL)-1β, IL-6, and tumor necrosis factor-α were detected.

RESULTS

At weeks 20 and 32, tidal volume, peak expiratory flow and expiratory flow at 50% tidal volume in the three TCM-treated groups were higher than those in the model group (P < 0.05). Femur weight, BMD, and BMC were significantly higher in the three TCM-treated groups and the aminophylline-treated group compared with the model group (P < 0.01), except for BMC in the Yiqizishen-treated group at week 20.

CONCLUSION

Bufeijianpi, Bufeiyishen, and Yiqizishen granules show good effects in the prevention and treatment of osteoporosis, which can alleviate airflow limitations and inflammation, improve BMD and BMC of the femur, and have favorable long-term effects.

Pulmonary function parameters in high-resolution computed tomography phenotypes of chronic obstructive pulmonary disease

BACKGROUND

Heterogeneity of clinical presentation of chronic obstructive pulmonary disease (COPD) attributes to different pathological basis. High-resolution computed tomography (HRCT) phenotypes of COPD may reflex the pathological basis of COPD indirectly by evaluating the small airway inflammation and emphysema. How the pulmonary function related with different HRCT phenotypes has not been well known. The aim was to explore the features of pulmonary function parameters in the 3 phenotypes.

METHODS

Sixty-three stable COPD patients were allocated in 3 groups based on HRCT findings: phenotype A (absence of emphysema, with minimal evidence of emphysema with or without bronchial wall thickening [BWT]), phenotype E (emphysema without BWT) and phenotype M (emphysema with BWT). The pulmonary function testing was also analyzed.

RESULTS

The values of forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC%), FEV1% and maximum expiratory flows (MEF)50% were the highest in phenotype A (P < 0.05), so was residual volume (RV)/total lung capacity (TLC%) in phenotype E (P < 0.05). Those with MEF50/MEF25 ratio >4.0 were more prevalence in phenotype A than in E and M (odds ratio = 2.214; P < 0.05). The occurrences of RV/TLC% >40% were higher in phenotype E than in A and M (odds ratio = 3.906; P < 0.05). Receiver operating characteristic analysis showed that the cutoff value of MEF50/MEF25 ratio for identifying phenotype A was 2.5, with sensitivity 66.7% and specificity 92.9%. The cutoff value of RV/TLC% for identifying phenotype E was 57.4%, with sensitivity 75.0% and specificity 79.1%.

CONCLUSIONS

The different features of pulmonary function parameters were found in various HRCT phenotypes; MEF50/MEF25 ratio could imply phenotype A, whereas RV/TLC% may be the indicator of phenotype E.

Imaging in occupational and environmental lung disease

PURPOSE OF REVIEW

Work-related and environmental lung disease is increasing over time and new antigens causing pulmonary response are described in medical literature every year with more or less specific imaging findings. The purposes of this review are to highlight the current role of imaging, describe classic as well as uncommon high-resolution computed tomography (HRCT) patterns helpful in guiding diagnosis and update the recent literature on this topic.

RECENT FINDINGS

Recent literature on imaging of occupational and environmental lung disease is scarce and is predominantly based on the HRCT appearance related to specific antigen exposure and on prognostic significance of findings.

SUMMARY

Knowledge of imaging modality potential and radiologic appearance may guide identification, characterization and follow-up of old and new occupational and environmental lung diseases. HRCT plays a key role in this context, having radiation exposure as a major limitation, especially in asymptomatic patients. Low-dose HRCT has the potential to be employed for screening and surveillance of the exposed individuals. However, future research is needed to further this field.

Non-emphysematous chronic obstructive pulmonary disease is associated with diabetes mellitus

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has been classically divided into blue bloaters and pink puffers. The utility of these clinical subtypes is unclear. However, the broader distinction between airway-predominant and emphysema-predominant COPD may be clinically relevant. The objective was to define clinical features of emphysema-predominant and non-emphysematous COPD patients.

METHODS

Current and former smokers from the Genetic Epidemiology of COPD Study (COPDGene) had chest computed tomography (CT) scans with quantitative image analysis. Emphysema-predominant COPD was defined by low attenuation area at -950 Hounsfield Units (LAA-950) ≥10%. Non-emphysematous COPD was defined by airflow obstruction with minimal to no emphysema (LAA-950 < 5%).

RESULTS

Out of 4197 COPD subjects, 1687 were classified as emphysema-predominant and 1817 as non-emphysematous; 693 had LAA-950 between 5-10% and were not categorized. Subjects with emphysema-predominant COPD were older (65.6 vs 60.6 years, p < 0.0001) with more severe COPD based on airflow obstruction (FEV1 44.5 vs 68.4%, p < 0.0001), greater exercise limitation (6-minute walk distance 1138 vs 1331 ft, p < 0.0001) and reduced quality of life (St. George's Respiratory Questionnaire score 43 vs 31, p < 0.0001). Self-reported diabetes was more frequent in non-emphysematous COPD (OR 2.13, p < 0.001), which was also confirmed using a strict definition of diabetes based on medication use. The association between diabetes and non-emphysematous COPD was replicated in the ECLIPSE study.

CONCLUSIONS

Non-emphysematous COPD, defined by airflow obstruction with a paucity of emphysema on chest CT scan, is associated with an increased risk of diabetes. COPD patients without emphysema may warrant closer monitoring for diabetes, hypertension, and hyperlipidemia and vice versa.

TRIAL REGISTRATION

Clinicaltrials.gov identifiers: COPDGene NCT00608764, ECLIPSE NCT00292552.

Inflammasome Activity in Non-Microbial Lung Inflammation

The understanding of interleukin-1 (IL-1) family cytokines in inflammatory disease has rapidly developed, due in part to the discovery and characterization of inflammasomes, which are multi-subunit intracellular protein scaffolds principally enabling recognition of a myriad of cellular stimuli, leading to the activation of caspase-1 and the processing of IL-1β and IL-18. Studies continue to elucidate the role of inflammasomes in immune responses induced by both microbes and environmental factors. This review focuses on the current understanding of inflammasome activity in the lung, with particular focus on the non-microbial instigators of inflammasome activation, including inhaled antigens, oxidants, cigarette smoke, diesel exhaust particles, mineral fibers, and engineered nanomaterials, as well as exposure to trauma and pre-existing inflammatory conditions such as metabolic syndrome. Inflammasome activity in these sterile inflammatory states contribute to diseases including asthma, chronic obstructive disease, acute lung injury, ventilator-induced lung injury, pulmonary fibrosis, and lung cancer.

Occupational risk factors for COPD phenotypes in the Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study

INTRODUCTION

The contribution of occupational exposure to the risk of chronic obstructive pulmonary disease COPD in population-based studies is of interest. We compared the performance of self-reported exposure to a newly developed JEM in exposure-response evaluation.

METHODS

We used cross-sectional data from Multi-Ethnic Study of Atherosclerosis (MESA), a population-based sample of 45-84 year olds free of clinical cardiovascular disease at baseline. MESA ascertained the most recent job and employment, and the MESA Lung Study measured spirometry, and occupational exposures for 3686 participants. Associations between health outcomes (spirometry defined airflow limitation and Medical Research Council-defined chronic bronchitis) and occupational exposure [self-reported occupational exposure to vapor-gas, dust, or fumes (VGDF), severity of exposure, and a job-exposure matrix (JEM)-derived score] were evaluated using logistic regression models adjusted for non-occupational risk factors.

RESULTS

The prevalence of airflow limitation was associated with self-reported exposure to vapor-gas (OR 2.6, 95%CI 1.1-2.3), severity of VGDF exposure (P-trend < 0.01), and JEM dust exposure (OR 2.4, 95%CI 1.1-5.0), and with organic dust exposure in females; these associations were generally of greater magnitude among never smokers. The prevalence of chronic bronchitis and wheeze was associated with exposure to VGDF. The association between airflow limitation and the combined effect of smoking and VGDF exposure showed an increasing trend. Self-reported vapor-gas, dust, fumes, years and severity of exposure were associated with increased prevalence of chronic bronchitis and wheeze (P < 0.001).

CONCLUSIONS

Airflow limitation was associated with self-reported VGDF exposure, its severity, and JEM-ascertained dust exposure in smokers and never-smokers in this multiethnic study.

Impact of self-reported gastroesophageal reflux disease in subjects from COPDGene cohort

BACKGROUND

The coexistence of gastroesophageal reflux disease (GERD) and COPD has been recognized, but there has been no comprehensive evaluation of the impact of GERD on COPD-related health status and patient-centered outcomes.

METHODS

Cross-sectional and longitudinal study of 4,483 participants in the COPDGene cohort who met GOLD criteria for COPD. Physician-diagnosed GERD was ascertained by questionnaire. Clinical features, spirometry and imaging were compared between COPD subjects without versus with GERD. We evaluated the relationship between GERD and symptoms, exacerbations and markers of microaspiration in univariate and multivariate models. Associations were additionally tested for the confounding effect of covariates associated with a diagnosis of GERD and the use of proton-pump inhibitor medications (PPIs). To determine whether GERD is simply a marker for the presence of other conditions independently associated with worse COPD outcomes, we also tested models incorporating a GERD propensity score.

RESULTS

GERD was reported by 29% of subjects with female predominance. Subjects with GERD were more likely to have chronic bronchitis symptoms, higher prevalence of prior cardiovascular events (combined myocardial infarction, coronary artery disease and stroke 21.3% vs. 13.4.0%, p < 0.0001). Subjects with GERD also had more severe dyspnea (MMRC score 2.2 vs. 1.8, p < 0.0001), and poorer quality of life (QOL) scores (St. George's Respiratory Questionnaire (SGRQ) total score 41.8 vs. 34.9, p < 0.0001; SF36 Physical Component Score 38.2 vs. 41.4, p < 0.0001). In multivariate models, a significant relationship was detected between GERD and SGRQ (3.4 points difference, p < 0.001) and frequent exacerbations at baseline (≥2 exacerbation per annum at inclusion OR 1.40, p = 0.006). During a mean follow-up time of two years, GERD was also associated with frequent (≥2/year exacerbations OR 1.40, p = 0.006), even in models in which PPIs, GERD-PPI interactions and a GERD propensity score were included. PPI use was associated with frequent exacerbator phenotype, but did not meaningfully influence the GERD-exacerbation association.

CONCLUSIONS

In COPD the presence of physician-diagnosed GERD is associated with increased symptoms, poorer QOL and increased frequency of exacerbations at baseline and during follow-up. These associations are maintained after controlling for PPI use. The PPI-exacerbations association could result from confounding-by-indication.

Defining COPD-Related Comorbidities, 2004-2014

Chronic obstructive pulmonary disease (COPD) is a disease of aging in combination with genetic, environmental, and behavioral risk factors. Aging and many of these risk factors are shared with other diseases, and, as a result, it is not surprising that patients with COPD often have coexistent diseases. This review of COPD comorbidities uses a framework in which coexistent diseases are considered important comorbidities if they are more frequent, have more severe consequences, influence the progression and outcomes of COPD, or are clustered together into proposed phenotypes, supplemented by a framework in which certain comorbidities are expected to share specific pathogenic mechanisms. This review explores classic COPD comorbidities such as cardiovascular disease, cachexia and sleep apnea, but also looks at more recently described comorbidities, such as gastroesophageal reflux, osteoporosis and depression/anxiety.

Trimethoprim-sulfamethoxazole treatment does not reverse obstructive pulmonary changes in pneumocystis-colonized nonhuman primates with SHIV infection

BACKGROUND

Despite antiretroviral therapy and trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis, Pneumocystis pneumonia remains an important serious opportunistic infection in HIV-infected persons. Pneumocystis (Pc) colonization in HIV-infected individuals and in HIV-uninfected smokers is associated with chronic obstructive pulmonary disease (COPD). We previously developed a nonhuman primate model of HIV infection and Pc colonization and demonstrated that Pc colonization correlated with COPD development. In the present study, we examined kinetics of COPD development in non-human primate and tested the effect of Pc burden reduction on pulmonary function by TMP-SMX treatment.

METHODS

Cynomolgus macaques (n = 16) were infected with simian/human immunodeficiency virus (SHIV89.6P), and natural Pc colonization was examined by nested polymerase chain reaction of serial bronchoalveolar lavage fluid and anti-Pc serology.

RESULTS

Eleven of 16 monkeys became Pc colonized by 16 weeks post simian-human immunodeficiency virus (SHIV) infection. Pc colonization of SHIV-infected monkeys led to progressive declines in pulmonary function as early as 4 weeks after Pc detection. SHIV-infected and Pc-negative monkeys maintained normal lung function. At 25 weeks post-SHIV infection, TMP-SMX treatment was initiated in 7 Pc-positive (Pc+) (TMP: 20 mg/kg and SMX: 100 mg/kg, daily for 48 weeks) and 5 Pc-negative (Pc-) monkeys. Four SHIV+/Pc+ remained untreated for the duration of the experiment. Detection frequency of Pc in serial bronchoalveolar lavage fluid (P < 0.001), as well as plasma Pc antibody titers (P = 0.02) were significantly reduced in TMP-SMX-treated macaques compared with untreated.

CONCLUSIONS

Reduction of Pc colonization by TMP-SMX treatment did not improve pulmonary function, supporting the concept that Pc colonization results in early, permanent obstructive changes in the lungs of immunosuppressed macaques.

Epidemiology of gastroesophageal reflux disease

The prevalence of gastroesophageal reflux disease (GERD) symptoms increased approximately 50% until the mid-1990s, when it plateaued. The incidence of complications related to GERD including hospitalization, esophageal strictures, esophageal adenocarcinoma, and mortality also increased during that time period, but the increase in esophageal adenocarcinoma has since slowed, and the incidence of strictures has decreased since the mid-1990s. GERD is responsible for the greatest direct costs in the United States of any gastrointestinal disease, and most of those expenditures are for pharmacotherapy. Risk factors for GERD include obesity, poor diet, lack of physical activity, consumption of tobacco and alcohol, and respiratory diseases.

Taking Healthy Steps: rationale, design and baseline characteristics of a randomized trial of a pedometer-based Internet-mediated walking program in veterans with chronic obstructive pulmonary disease

Background

Low levels of physical activity are common in patients with chronic obstructive pulmonary disease (COPD), and a sedentary lifestyle is associated with poor outcomes including increased mortality, frequent hospitalizations, and poor health-related quality of life. Internet-mediated physical activity interventions may increase physical activity and improve health outcomes in persons with COPD.

Methods/Design

This manuscript describes the design and rationale of a randomized controlled trial that tests the effectiveness of Taking Healthy Steps, an Internet-mediated walking program for Veterans with COPD. Taking Healthy Steps includes an uploading pedometer, a website, and an online community. Eligible and consented patients wear a pedometer to obtain one week of baseline data and then are randomized on a 2:1 ratio to Taking Healthy Steps or to a wait list control. The intervention arm receives iterative step-count feedback; individualized step-count goals, motivational and informational messages, and access to an online community. Wait list controls are notified that they are enrolled, but that their intervention will start in one year; however, they keep the pedometer and have access to a static webpage.

Discussion

Participants include 239 Veterans (mean age 66.7 years, 93.7% male) with 155 randomized to Taking Healthy Steps and 84 to the wait list control arm; rural-living (45.2%); ever-smokers (93.3%); and current smokers (25.1%). Baseline mean St. George’s Respiratory Questionnaire Total Score was 46.0; 30.5% reported severe dyspnea; and the average number of comorbid conditions was 4.9. Mean baseline daily step counts was 3497 (+/- 2220).

Veterans with COPD can be recruited to participate in an online walking program. We successfully recruited a cohort of older Veterans with a significant level of disability including Veterans who live in rural areas using a remote national recruitment strategy.

Trial registration

Clinical Trials.gov NCT01102777

The clinical impact of non-obstructive chronic bronchitis in current and former smokers

BACKGROUND

As the clinical significance of chronic bronchitis among smokers without airflow obstruction is unclear, we sought to determine morbidity associated with this disorder.

METHODS

We examined subjects from the COPDGene study and compared those with FEV1/FVC ≥ 0.70, no diagnosis of asthma and chronic bronchitis as defined as a history of cough and phlegm production for ≥ 3 months/year for ≥ 2 years (NCB) to non-obstructed subjects without chronic bronchitis (CB-). Multivariate analysis was used to determine factors associated with and impact of NCB.

RESULTS

We identified 597 NCB and 4283 CB- subjects. NCB participants were younger (55.4 vs. 57.2 years, p < 0.001) with greater tobacco exposure (42.9 vs. 37.8 pack-years, p < 0.001) and more often current smokers; more frequently reported occupational exposure to fumes (52.8% vs. 42.2%, p < 0.001), dust for ≥ 1 year (55.3% vs. 42.0%, p < 0.001) and were less likely to be currently working. NCB subjects demonstrated worse quality-of-life (SGRQ 35.6 vs. 15.1, p < 0.001) and exercise capacity (walk distance 415 vs. 449 m, p < 0.001) and more frequently reported respiratory "flare-ups" requiring treatment with antibiotics or steroids (0.30 vs. 0.10 annual events/subject, p < 0.001) prior to enrollment and during follow-up (0.34 vs. 0.16 annual events/subject, p < 0.001). In multivariate analysis, current smoking, GERD, sleep apnea and occupational exposures were significantly associated with NCB.

CONCLUSIONS

While longitudinal data will be needed to determine whether NCB progresses to COPD, NCB patients have poorer quality-of-life, exercise capacity and frequent respiratory events. Beyond smoking cessation interventions, further research is warranted to determine the benefit of other therapeutics in this population. Clinical Trials Registration # NCT00608764 (http://clinicaltrials.gov/show/NCT00608764). Link to study protocol: http://www.copdgene.org/sites/default/files/COPDGeneProtocol-5-0_06-19-2009.pdf.

MAPK/NF-κB-dependent upregulation of kinin receptors mediates airway hyperreactivity: a new perspective for the treatment

Airway hyperreactivity (AHR) is a major feature of asthmatic and inflammatory airways. Cigarette smoke exposure, and bacterial and viral infections are well-known environmental risk factors for AHR, but knowledge about the underlying molecular mechanisms on how these risk factors lead to the development of AHR is limited. Activation of intracellular mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-κB) and their related signal pathways including protein kinase C (PKC), phosphoinositide 3-kinase (PI3K) and protein kinase A (PKA) signaling pathways may result in airway kinin receptor upregulation, which is suggested to play an important role in the development of AHR. Environmental risk factors trigger the production of pro-inflammatory mediators such as tumor necrosis factor-α (TNF-α) and interleukins (ILs) that activate intracellular MAPK- and NF-κB-dependent inflammatory pathways, which subsequently lead to AHR via kinin receptor upregulation. Blockage of intracellular MAPK/NF-κB signaling prevents kinin B₁ and B₂ receptor expression in the airways, resulting in a decrease in the response to bradykinin (kinin B₂ receptor agonist) and des-Arg⁹-bradykinin (kinin B₁ receptor agonist). This suggests that MAPK- and NF-κB-dependent kinin receptor upregulation can provide a novel option for treatment of AHR in asthmatic as well as in other inflammatory airway diseases.