Systemic manifestations and comorbidities of COPD

Modified BODE indexes: Agreement between multidimensional prognostic systems based on oxygen uptake

Aim

It has been recently shown that the original BODE index has a high degree of correlation with two modified BODE indexes using maximal oxygen uptake expressed either as mL/min/kg (mBODE) or as the percentage predicted (mBODE%). In this study we investigated the agreement between the two modified BODE indexes (mBODE and mBODE%) in patients with stable chronic obstructive pulmonary disease (COPD).

Methods

A total of 169 patients with stable COPD were enrolled in this cross-sectional study. Differences between the two mBODE indexes were assessed using kappa coefficients and Bland-Altman plots. One out of every three patients underwent the six-minute walking test to investigate the agreement with the original BODE index.

Results

Correlations between the two mBODE indexes with each other (r = 0.96, P < 0.001) and with the original BODE index (mBODE r = 0.88, P < 0.001; mBODE% r = 0.93, P < 0.001) were excellent. However, the two mBODE indexes were significantly different from each other (mBODE 5.27 ± 2.3 versus mBODE% 4.31 ± 2.5; P < 0.001). The kappa coefficients were significantly lower (entire study group k = 0.5, P < 0.001) for every GOLD stage. The mean difference between the two mBODE indexes was 0.8 ± 0.6 units. Differences with the original BODE were higher for the mBODE (1.8 ± 0.9) than for the mBODE% (0.6 ± 0.8).

Conclusions

The new mBODE indexes are highly correlated but significantly different from each other. The differences between the novel indexes deserve further scrutiny.

Coexisting chronic obstructive pulmonary disease and heart failure: implications for treatment, course and mortality

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) and heart failure are prevalent comorbidities affecting a huge proportion of the world population, responsible for significant morbidity and mortality. Their coexistence is more frequent than previously recognized and poses important diagnostic and therapeutic challenges. Prognosis of patients with concurrent heart failure and COPD has not been comprehensively addressed. With this review, we intend to emphasize the diagnosis and prognosis implications of the two coexisting conditions and to highlight the therapeutic constraints posed by the combination.

RECENT FINDINGS

Progressively, more attention has been given to the interplay between COPD and heart failure. The combination is frequent, but largely unrecognized due to overlapping clinical manifestations. Patients presenting with both conditions seem to have an ominous course. Despite the overwhelming evidence supporting cardioselective beta-blockade safety and tolerability in COPD patients, beta-blockers are underprescribed to heart failure patients with concomitant COPD.

SUMMARY

COPD and heart failure coexistence is often overlooked. COPD diagnosis can remain unsuspected in heart failure patients due to similar symptoms. Although beta-blockers are well tolerated in COPD patients, they are overall less prescribed in this challenging population. COPD, at least at severe degrees of airflow obstruction, predicts a worse prognosis in heart failure patients.

Predictors of mortality in COPD

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in adults. Although FEV(1) remains the most important physiologic indicator of the severity of airflow obstruction in COPD, its predictive value for mortality is weak when it is higher than 50% of predicted. Furthermore, other easily obtainable clinical variables predict mortality better than the FEV(1) in COPD patients with a wide range of airflow limitation. Chief among these predictors are functional dyspnea, exercise capacity, and the body mass index (BMI), although emerging research suggests a potential role for biomarker profiles in outcome predictions. The validated multidimensional BMI (B), degree of airflow obstruction as expressed by the FEV(1) (O), dyspnea with the modified medical research council (D), and exercise (E) measured with the 6min walk or BODE index encompasses the predictive validity of the best of these variables into a single surrogate measure of disease severity and survival. This article reviews these predictors of mortality in COPD.

Systemic inflammation in chronic obstructive pulmonary disease: may adipose tissue play a role? Review of the literature and future perspectives

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. Low-grade systemic inflammation is considered a hallmark of COPD that potentially links COPD to increased rate of systemic manifestations of the disease. Obesity with/without the metabolic syndrome and cachexia represent two poles of metabolic abnormalities that may relate to systemic inflammation. On one hand systemic inflammatory syndrome likely reflects inflammation in the lungs, i.e. results from lung-to plasma spillover of inflammatory mediators. On the other hand, obesity-related hypoxia results in local inflammatory response within adipose tissue per se, and may contribute to elevations in circulatory mediators by spillover from the adipose tissue to the systemic compartment. The extent to which systemic hypoxia contributes to the adipose tissue inflammation remains unknown. We assume that in patients with COPD and concurrent obesity at least three factors play a role in the systemic inflammatory syndrome: the severity of pulmonary impairment, the degree of obesity-related adipose tissue hypoxia, and the severity of systemic hypoxia due to reduced pulmonary functions. The present review summarizes the epidemiological and clinical evidence linking COPD to obesity, the role of adipose tissue as an endocrine organ, and the role of hypoxia in adipose tissue inflammation.

COPD and the risk of tuberculosis--a population-based cohort study

Background

Both chronic obstructive pulmonary disease (COPD) and tuberculosis (TB) primarily affect the lungs and are major causes of morbidity and mortality worldwide. COPD and TB have common risk factors such as smoking, low socioeconomic status and dysregulation of host defence functions. COPD is a prevalent co-morbid condition, especially in elderly with TB but in contrast to other diseases known to increase the risk of TB, relatively little is known about the specific relationship and impact from COPD on TB-incidence and mortality.

Methods and Findings

All individuals ≥40 years of age, discharged with a diagnosis of COPD from Swedish hospitals 1987–2003 were identified in the Swedish Inpatient Register (n = 115,867). Records were linked to the Swedish Tuberculosis Register 1989–2007 and the relative risk of active TB in patients with COPD compared to control subjects randomly selected from the general population (matched for sex, year of birth and county of residence) was estimated using Cox regression. The analyses were stratified by year of birth, sex and county of residence and adjusted for immigration status, socioeconomic status (SES) and inpatient co-morbidities previously known to increase the risk of TB. COPD patients had a three-fold increased hazard ratio (HR) of developing active TB (HR 3.0 (95% confidence interval 2.4 to 4.0)) that was mainly dependent on an increased risk of pulmonary TB. In addition, logistic regression estimates showed that COPD patients who developed active TB had a two-fold increased risk of death from all causes within first year after the TB diagnosis compared to the general population control subjects with TB (OR 2.2, 95% confidence interval 1.2 to 4.1).

Conclusions

This population-based study comprised of a large number of COPD patients shows that these patients have an increased risk of developing active TB compared to the general population. The results raise concerns that the increasing global burden of COPD will increase the incidence of active TB. The underlying contributory factors need to be disentangled in further studies.

CT scan findings of emphysema predict mortality in COPD

BACKGROUND

Emphysematous change as assessed by CT imaging has been reported to correlate with COPD prognostic factors such as FEV(1) and diffusing capacity of the lung for carbon monoxide (Dlco). However, few studies have assessed the relationship between CT scan assessment and COPD mortality from mild to severe stages of the disease. In this study, we analyzed this relationship in patients with various stages of COPD.

METHODS

Two hundred and fifty-one outpatients with stable COPD were included in the study. CT scan and pulmonary function tests were performed at study entry in a single institution. The percentage of low attenuation area was measured to quantitatively evaluate emphysematous change with a custom-made software. Prognostic data also were collected, and the median follow-up time was 8 years.

RESULTS

Of the 251 patients, 79 died, with 40 classified as respiratory deaths not involving lung cancer. Univariate Cox analysis revealed that emphysematous change as assessed by CT scan, lung function, age, or BMI were significantly correlated with mortality. Multivariate analysis revealed that emphysematous change as assessed by CT scan had the best association with mortality.

CONCLUSIONS

Emphysematous change as assessed by CT scan predicts respiratory mortality in outpatients with various stages of COPD.

The preclinical pharmacology of roflumilast--a selective, oral phosphodiesterase 4 inhibitor in development for chronic obstructive pulmonary disease

After more than two decades of research into phosphodiesterase 4 (PDE4) inhibitors, roflumilast (3-cyclopropylmethoxy-4-difluoromethoxy-N-[3,5-di-chloropyrid-4-yl]-benzamide) may become the first agent in this class to be approved for patient treatment worldwide. Within the PDE family of 11 known isoenzymes, roflumilast is selective for PDE4, showing balanced selectivity for subtypes A-D, and is of high subnanomolar potency. The active principle of roflumilast in man is its dichloropyridyl N-oxide metabolite, which has similar potency as a PDE4 inhibitor as the parent compound. The long half-life and high potency of this metabolite allows for once-daily, oral administration of a single, 500-microg tablet of roflumilast. The molecular mode of action of roflumilast--PDE4 inhibition and subsequent enhancement of cAMP levels--is well established. To further understand its functional mode of action in chronic obstructive pulmonary disease (COPD), for which roflumilast is being developed, a series of in vitro and in vivo preclinical studies has been performed. COPD is a progressive, devastating condition of the lung associated with an abnormal inflammatory response to noxious particles and gases, particularly tobacco smoke. In addition, according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), significant extrapulmonary effects, including comorbidities, may add to the severity of the disease in individual patients, and which may be addressed preferentially by orally administered remedies. COPD shows an increasing prevalence and mortality, and its treatment remains a high, unmet medical need. In vivo, roflumilast mitigates key COPD-related disease mechanisms such as tobacco smoke-induced lung inflammation, mucociliary malfunction, lung fibrotic and emphysematous remodelling, oxidative stress, pulmonary vascular remodelling and pulmonary hypertension. In vitro, roflumilast N-oxide has been demonstrated to affect the functions of many cell types, including neutrophils, monocytes/macrophages, CD4+ and CD8+ T-cells, endothelial cells, epithelial cells, smooth muscle cells and fibroblasts. These cellular effects are thought to be responsible for the beneficial effects of roflumilast on the disease mechanisms of COPD, which translate into reduced exacerbations and improved lung function. As a multicomponent disease, COPD requires a broad therapeutic approach that might be achieved by PDE4 inhibition. However, as a PDE4 inhibitor, roflumilast is not a direct bronchodilator. In summary, roflumilast may be the first-in-class PDE4 inhibitor for COPD therapy. In addition to being a non-steroid, anti-inflammatory drug designed to target pulmonary inflammation, the preclinical pharmacology described in this review points to a broad functional mode of action of roflumilast that putatively addresses additional COPD mechanisms. This enables roflumilast to offer effective, oral maintenance treatment for COPD, with an acceptable tolerability profile and the potential to favourably affect the extrapulmonary effects of the disease.

Chronic obstructive pulmonary disease: effects beyond the lungs

Peter Barnes discusses the growing epidemic of chronic obstructive pulmonary disease (COPD), especially in developing countries and among nonsmokers.

Decreasing cardiac chamber sizes and associated heart dysfunction in COPD: role of hyperinflation

BACKGROUND

Little is known about the role of abnormal lung function in heart size and heart dysfunction in patients with COPD. We studied the relationship of lung function with heart size and heart dysfunction and associated consequences for 6-min walk distance (6MWD) in patients with COPD of different severitites.

METHODS

In 138 patients with COPD (Global Initiative for Obstructive Lung Disease [GOLD] I-IV), we measured the size of all cardiac chambers, left ventricular diastolic dysfunction (relaxation and filling), and global right ventricular dysfunction (Tei-index) by echocardiography. We also measured lung function (spirometry, body plethysmography, and diffusion capacity) and 6MWD.

RESULTS

The size of all cardiac chambers decreased with increasing GOLD stage. Overall, moderate relationships existed between variables of lung function and cardiac chamber sizes. Static hyperinflation (inspiratory-to-total lung capacity ratio [IC/TLC], functional residual capacity, and residual volume) showed stronger associations with cardiac chamber sizes than airway obstruction or diffusion capacity. IC/TLC correlated best with cardiac chamber sizes and was an independent predictor of cardiac chamber sizes after adjustment for body surface area. Patients with an IC/TLC < or = 0.25 had a significantly impaired left ventricular diastolic filling pattern and a significantly impaired Tei-index compared with patients with an IC/TLC > 0.25. An impaired left ventricular diastolic filling pattern was independently associated with a reduced 6MWD.

CONCLUSIONS

An increasing rate of COPD severity is associated with a decreasing heart size. Hyperinflation could play an important role regarding heart size and heart dysfunction in patients with COPD.

Does physical inactivity cause chronic obstructive pulmonary disease?

COPD (chronic obstructive pulmonary disease) is the most common pulmonary disease and is the only common cause of death in which mortality is presently rising. It is caused by the inhalation of smoke, which leads to oxidative stress and inflammation both in the lungs and systemically. Reduced physical activity is a well-recognized consequence of the condition, but we argue here that inactivity is itself an early cause of lung function decline and symptoms. This hypothesis is supported by data from population studies that link activity levels to decline in spirometric indices, both in smokers and non-smokers. In addition, smokers with low physical activity levels are more likely to be diagnosed subsequently with COPD. Physical exercise reduces oxidative stress, has an anti-inflammatory effect and reduces the frequency of upper respiratory tract infections, providing a number of mechanisms by which it could attenuate the harmful effects of smoking. There is sufficient evidence to justify population trials of lifestyle interventions aimed at improving physical activity levels and reducing lung function decline in people diagnosed with early COPD through spirometry screening.

Identification and clinical association of anti-cytokeratin 18 autoantibody in COPD

The etiology of chronic obstructive pulmonary disease (COPD) remains unclear. A mechanism involving the autoimmune reaction in the pathogenesis of COPD has been proposed but not confirmed. The aim of this study was to investigate whether serum autoantibodies against pulmonary cellular proteins are present in COPD patients and to identify their autoantigens if possible. Samples from 50 COPD patients and 42 control subjects were studied. Circulating autoantibodies were detected by Western blot. Immunoprecipitation and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry were used to identify the autoantigens. Autoantibodies against pulmonary cellular antigens were found in the sera of COPD patients. Specifically, an autoantibody against the 45-kDa human cytokeratin 18 protein was found in 76.0% of COPD patients and 23.8% of control subjects (p<0.001). Furthermore, the cytokeratin 18 autoantibody level was positively correlated with the FEV(1) (L) (p=0.013) and FEV(1) (%pred.) (p=0.043) values observed in COPD patients. This study identified the pulmonary epithelial cytokeratin 18 protein as a COPD-associated autoantigen and found that anti-cytokeratin 18 autoantibodies were prevalent in COPD patients. Our results support the hypothesis that humoral autoimmunity may be involved in the pathogenesis of COPD.

O papel do estresse oxidativo na DPOC: conceitos atuais e perspectivas

A DPOC é uma causa importante de morbidade e mortalidade em escala global. As manifestações clínicas e funcionais da DPOC resultam de danos pulmonares provocados por um conjunto de mecanismos, incluindo o estresse oxidativo, a inflamação, o desequilíbrio do sistema protease-antiprotease e a apoptose. O estresse oxidativo é central na gênese da DPOC, pois além de provocar dano direto às estruturas pulmonares, amplifica os demais mecanismos. Os eventos celulares e moleculares responsáveis pelo dano pulmonar antecedem em muito a expressão clínica e funcional da DPOC. Os broncodilatadores, principais drogas empregadas atualmente no tratamento da DPOC, não são eficazes em reduzir a progressão da doença. Avanços na compreensão da patogênese da DPOC aliados a esforços renovados na pesquisa básica e clínica deverão permitir sua detecção na fase pré-clínica e possibilitar um monitoramento mais adequado de sua atividade, além de permitir a introdução de novas modalidades de agentes terapêuticos capazes de impedir eficazmente sua progressão.

Long-term therapy in COPD: any evidence of adverse effect on bone?

Patients with COPD have high risk for osteoporosis and fractures. Hip and vertebral fractures might impair mobility, and vertebral fractures further reduce lung function. This review discusses the evidence of bone loss due to medical treatment opposed to disease severity and risk factors for COPD, and therapeutic options for the prevention and treatment of osteoporosis in these patients. A review of the English-language literature was conducted using the MEDLINE database until June 2009. Currently used bronchodilators probably lack adverse effect on bone. Oral corticosteroids (OCS) increase bone resorption and decrease bone formation in a dose response relationship, but the fracture risk is increased more than reflected by bone densitometry. Inhaled corticosteroids (ICS) have been associated with both increased bone loss and fracture risk. This might be a result of confounding by disease severity, but high doses of ICS have similar effects as equipotent doses of OCS. The life-style factors should be modified, use of regular OCS avoided and use of ICS restricted to those with evidenced effect and probably kept at moderate doses. The health care should actively reveal risk factors, include bone densitometry in fracture risk evaluation, and give adequate prevention and treatment for osteoporosis.

New drugs for exacerbations of chronic obstructive pulmonary disease

Tobacco smoking is the dominant risk factor for chronic obstructive pulmonary disease (COPD), but viral and bacterial infections are the major causes of exacerbations in later stages of disease. Reactive oxygen species (ROS), pathogen-associated molecular patterns (PAMPs), and damage-associated molecular patterns (DAMPs) activate families of pattern recognition receptors (PRRs) that include the toll-like receptors (TLRs). This understanding has led to the hypothesis that COPD is an archetypal disease of innate immunity. COPD is characterised by abnormal response to injury, with altered barrier function of the respiratory tract, an acute phase reaction, and excessive activation of macrophages, neutrophils, and fibroblasts in the lung. The activated non-specific immune system then mediates the processes of inflammation and repair, fibrosis, and proteolysis. COPD is also associated with corticosteroid resistance, abnormal macrophage and T-cell populations in the airway, autoinflammation and autoimmunity, aberrant fibrosis, accelerated ageing, systemic and concomitant disease, and defective regeneration. Such concepts have been used to generate a range of molecular targets, and clinical trials are taking place to identify effective drugs for the prevention and treatment of COPD exacerbations.

The cytokine network in chronic obstructive pulmonary disease

Multiple cytokines play a role in the orchestration of inflammation in inflammatory airway diseases, such as chronic obstructive pulmonary disease, through the recruitment, activation and survival of inflammatory cells. Lymphokines secreted from T cells regulate the pattern of inflammation, whereas proinflammatory cytokines amplify and perpetuate the inflammatory response. Multiple chemokines recruit inflammatory cells from the circulation into the lungs and many growth factors maintain this inflammation and lead to characteristic structural changes in the airways. There are several therapeutic approaches that target cytokine-mediated inflammation in chronic obstructive pulmonary disease, but blocking specific cytokines may not provide clinical benefit, whereas broad-spectrum anti-inflammatory approaches are more likely to be clinically effective.

The possible role of granzyme B in the pathogenesis of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a highly prevalent inflammatory lung condition characterized by airways disease and emphysema, and the precise mechanism of pathogenesis is poorly understood. The consistent features of COPD include protease-antiprotease imbalance, inflammation and accelerated aging caused by apoptosis or senescence. One family of molecules involved in all of these processes is the granzymes, serine proteases with the best-known member being granzyme B (GzmB). The majority of GzmB is released unidirectionally towards target cells, but GzmB can also be released nonspecifically and escape into the extracellular environment. GzmB is capable of cleaving extracellular matrix (ECM) proteins in vitro, and the accumulation of GzmB in the extracellular milieu during chronic inflammation in COPD could contribute to ECM degradation and remodelling and, consequently, the emphysematous phenotype in the lung. Preliminary studies suggest that increased GzmB expression is associated with increased COPD severity, and this may represent a promising new target for drug and biomarker discovery in COPD. In this paper, we review the potential pathogenic contributions of GzmB to the pathogenesis of COPD.