Chronic obstructive pulmonary disease: current burden and future projections

Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

RATIONALE

There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.

OBJECTIVES

To describe the ability of these measures of emphysema and airway wall thickness to predict respiratory symptoms in subjects with and without chronic obstructive pulmonary disease (COPD).

METHODS

We included 463 subjects with chronic obstructive pulmonary disease (COPD) (65% men) and 488 subjects without COPD (53% men). All subjects were current or ex-smokers older than 40 years. They underwent spirometry and high-resolution computed tomography examination, and completed an American Thoracic Society questionnaire on respiratory symptoms.

MEASUREMENTS AND MAIN RESULTS

Median (25th percentile, 75th percentile) percent low-attenuation areas less than -950 Hounsfield units (%LAA) was 7.0 (2.2, 17.8) in subjects with COPD and 0.5 (0.2, 1.3) in subjects without COPD. Mean (SD) standardized airway wall thickness (AWT) at an internal perimeter of 10 mm (AWT-Pi10) was 4.94 (0.33) mm in subjects with COPD and 4.77 (0.29) in subjects without COPD. Both %LAA and AWT-Pi10 were independently and significantly related to the level of dyspnea among subjects with COPD, even after adjustments for percent predicted FEV(1). AWT-Pi10 was significantly related to cough and wheezing in subjects with COPD, and to wheezing in subjects without COPD. Odds ratios (95% confidence intervals) for increased dyspnea in subjects with COPD and in subjects without COPD were 1.9 (1.5-2.3) and 1.9 (0.6-6.6) per 10% increase in %LAA, and 1.07 (1.01-1.14) and 1.11 (0.99-1.24) per 0.1-mm increase in AWT-Pi10, respectively.

CONCLUSIONS

Quantitative computed tomography assessment of the lung parenchyma and airways may be used to explain the presence of respiratory symptoms beyond the information offered by spirometry.

Anticholinergic treatment in airways diseases

The prevalence of chronic airways diseases such as chronic obstructive pulmonary disease and asthma is increasing. They lead to symptoms such as a cough and shortness of breath, partially through bronchoconstriction. Inhaled anticholinergics are one of a number of treatments designed to treat bronchoconstriction in airways disease. Both short-acting and long-acting agents are now available and this review highlights their efficacy and adverse event profile in chronic airways diseases.

The burden of COPD in Africa: a literature review and prospective survey of the availability of spirometry for COPD diagnosis in Africa

OBJECTIVES

To ascertain the known burden of chronic obstructive pulmonary disease (COPD) in Africa and of spirometry use to indicate the possibility of further unpublished data becoming shortly available.

METHOD

Literature review.

RESULTS

Screening of 132 articles yielded 22 relevant articles, of which only six used spirometry based data. A total of 106 physicians in 34 countries were contacted and only 23 reported satisfactory use and availability of spirometry.

CONCLUSIONS

Current estimates of COPD burden in Africa are based on an unreliably small dataset. Acquisition of further data will require substantial investment in lung function equipment and training.

High prevalence of undiagnosed airflow limitation in patients with cardiovascular disease

BACKGROUND

The prevalence of airflow limitation (AL) in patients with cardiovascular disease (CVD) is unknown, and whether AL is adequately diagnosed and treated in these patients has not been investigated before, to our knowledge.

METHODS

We compared clinical and spirometric data in three groups of individuals. Two of them were participants in the follow-up of an ongoing population-based study according to the presence or absence of CVD. The third group included patients with coronary artery disease (CAD) confirmed by coronariography regularly visited at a tertiary referral university hospital. AL was defined according to the Global Initiative for Obstructive Lung Disease guidelines.

RESULTS

We studied 450 population participants without CVD, 52 population participants with CVD, and 119 hospital patients with CAD. The prevalence of AL in these three groups was 17.5% (95% CI, 14.0-21.0), 19.2% (95% CI, 8.1-30.7), and 33.6% (95% CI, 25.0-42.2), respectively (P < .05). Underdiagnosis of AL ranged from 60% in population participants with CVD up to 87.2% in hospital patients with CAD. Sixty percent of those with spirometrically confirmed AL (in all three groups) did not receive any respiratory treatment.

CONCLUSIONS

AL is frequent in individuals with CVD, particularly in those with CAD attended in the hospital, is largely underdiagnosed and therefore is highly undertreated.

TRIAL REGISTRATION

Clinicaltrials.gov; Identifier: NCT00787748.

Racial and sex differences in chronic obstructive pulmonary disease susceptibility, diagnosis, and treatment

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is an increasing cause of morbidity and mortality worldwide. Although COPD has historically been considered a disease of white male smokers, it now clearly impacts both sexes and all races, with mortality rising fastest in women and African-Americans. Given the scarcity of data about non-African-American minorities, this review will focus on the disparities in COPD susceptibility, diagnosis, and treatment between men and women and between African-Americans and whites.

RECENT FINDINGS

Although the changing epidemiology of COPD in part reflects the changing epidemiology of cigarette smoking, there are data suggesting that women and African-Americans may be particularly susceptible to tobacco smoke and that the diagnosis, treatment, and natural history of the disease are influenced by race and sex.

SUMMARY

The possibility that sex or race or both, may influence COPD susceptibility and progression is of critical importance, and may mean that the potential future impact of the disease has been underestimated. Unfortunately, our understanding of these differences and the efficacy of standard COPD treatments in women and minorities remains limited by the low enrollment in clinical trials.

Screening for and early detection of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a substantially underdiagnosed disorder, with the diagnosis typically missed or delayed until the condition is advanced. Spirometry is the most frequently used pulmonary function test and enables health professionals to make an objective measurement of airflow obstruction and assess the degree to which it is reversible. As a diagnostic test for COPD, spirometry is a reliable, simple, non-invasive, safe, and non-expensive procedure. Early diagnosis of COPD should provide support for smoking cessation initiatives and lead to reduction of the societal burden of the disease, but definitive confirmation of both proves elusive. Despite substantial effort and investment, implementation of quality spirometry is deficient because of several hurdles and limitations, described in this Review. All in all, spirometry is recognised as the essential test for diagnosis and monitoring of COPD.

Procalcitonin as a prognostic factor in severe acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

Little is known about the value of procalcitonin in predicting mortality in patients with an exacerbation of COPD. This study evaluated the clinical and biological predictors of intensive care unit (ICU) mortality in patients with a severe acute exacerbation of COPD.

METHODS

A prospective observational cohort study was conducted of consecutive patients with severe acute exacerbation of COPD requiring intubation and mechanical ventilation. At ICU admission, data were collected on the patients' clinical condition, blood leukocyte count, C-reactive protein and procalcitonin. Cox proportional hazards model was used to determine the risk factors for ICU mortality.

RESULTS

One hundred and sixteen patients were included in this study. Mean age was 67 years. The mean simplified acute physiology score was 43. Sixty-five per cent of study patients had chronic respiratory insufficiency. Bacteria were cultured at levels considered significant in 36% of study patients. Logistic organ dysfunction score (hazard ratio (95% CI) = 1.19 (1.03-1.37), P = 0.013), rapidly fatal underlying disease (3.33 (1.40-7.87), P = 0.003) and procalcitonin level (1.01 (1-1.03), P = 0.018) were independently associated with increased risk for ICU mortality. Non-invasive mechanical ventilation use before intubation was independently associated with reduced risk for ICU mortality (0.34 (0.14-0.84), P = 0.020).

CONCLUSIONS

In patients with severe acute exacerbation of COPD requiring intubation and mechanical ventilation, logistic organ dysfunction score, rapidly fatal underlying disease and procalcitonin are independently associated with increased risk for ICU mortality. Non-invasive mechanical ventilation use before intubation was independently associated with reduced risk for ICU mortality.

Dual PDE3/4 inhibitors as therapeutic agents for chronic obstructive pulmonary disease

Phosphodiesterase (PDE)4, and to a lesser extent, PDE3/4 inhibitors have attracted considerable interest as potential therapeutic agents for diseases including chronic obstructive pulmonary disease. Indeed, ibudilast and theophylline are utilized clinically, and roflumilast is in late-stage clinical development. Unfortunately, however many PDE4 and dual PDE3/4 inhibitors have failed in early development due to low therapeutic ratios. The majority of these compounds are however orally administered and non-selective for either PDE3(A, B) or PDE4(A, B, C, D) subtypes. Developing an inhaled dual PDE3/4 inhibitor with subtype specificity may represent one strategy to improve the therapeutic index. Indeed combined inhibition of PDE3 and PDE4 inhibitor has additive and synergistic anti-inflammatory and bronchodilatory effects versus inhibition of either PDE3 or PDE4 alone. Given that synergy has been seen in terms of efficacy end points, an obvious concern is that synergy may also be observed in side effects. Interestingly, however, no synergy or additive effects with a combination of a PDE3 and PDE4 inhibitor in a cardiomyocyte assay were observed. This review will summarize the rationale for developing an inhaled dual PDE3/4 inhibitor, as a treatment for chronic obstructive pulmonary disease together with recent advances in trying to understand the pathogenesis of PDE inhibitor-induced mesenteric vasculitis (a key potential dose-limiting side effect of these agents), highlighting potential early and sensitive predictive biomarkers.

[Early detection of smoking related chronic obstructive pulmonary disease in Vietnam]

INTRODUCTION

Epidemiological studies of chronic obstructive pulmonary disease (COPD) are rare in the developing countries, particularly in Viet Nam where the consumption of tobacco continues to increase. The aim of this study was to evaluate the feasibility of early screening of smokers for bronchial obstruction using the Piko-6 apparatus.

MATERIALS AND METHODS

Smokers over 40 years of age who had smoked for more than 10 years were included. The subjects were classified into 3 groups according to the degree of bronchial obstruction measured by the Piko-6. (group 1: FEV1/FEV6>0.8; group 2: 0.7-0.8; group 3:<0.7). The smokers in group 3 and a sample of the smokers in groups 1 and 2 were recalled for full spirometric assessment.

RESULTS

2397 smokers were included, comprising 2130 active smokers and 267 ex-smokers. The mean age was 52 +/- 13 years. The mean smoking history was 24 +/- 13 pack years. 267 smokers from the 3 groups responded to the recall for full investigation. The prevalence of COPD detected by the Piko-6 in the study population was 13.5%. For the threshold FEV1/FEV6<0.7 and with the detected prevalence, the Piko-6 had a sensitivity of 97.8%, a specificity of 93.8%, a positive predictive value of 71% and a negative predictive value of 99.6% (confidence interval 95%).

CONCLUSIONS

The Piko-6 is a useful tool for the early screening for COPD in smokers in a developing country where the prevalence of this disease appears to be under estimated.

Sputum IL-5 concentration is associated with a sputum eosinophilia and attenuated by corticosteroid therapy in COPD

BACKGROUND

Airway inflammation in chronic obstructive pulmonary disease (COPD) is predominately neutrophilic, but some subjects demonstrate eosinophilic airway inflammation. Whether these inflammatory phenotypes have differential cytokine and chemokine expression is unknown.

OBJECTIVES

To assess the sputum concentrations of cytokines and chemokines and their response to oral corticosteroid therapy in COPD subjects with or without a sputum eosinophilia.

METHODS

Cytokine and chemokine concentrations were measured using the meso-scale device platform. To assess validity, recovery of exogenous spikes was examined. The concentrations of the validated mediators were measured in COPD sputum from subjects with or without a sputum eosinophilia. In a subgroup with a sputum eosinophilia, the response to oral prednisolone 10 mg for 1 month was examined.

RESULTS

The recovery in sputum of exogenous spiked mediators was >80% in 11/26 cytokines and chemokines. In supernatants from eosinophilic (n = 39) versus non-eosinophilic (n = 59) sputa, the geometric mean (95% CI) concentration was increased for IL-5 [9.0 (4.5-18) pg/ml vs. 3.6 (2.7-6.3) pg/ml, p = 0.03]. IL-5 alone was correlated with sputum eosinophil counts (r = 0.33, p = 0.001), and was attenuated following treatment with prednisolone [n = 9; mean difference 2.3 pg/ml (0.2-4.3), p = 0.032].

CONCLUSION

We have validated the use of the meso-scale device platform for cytokine and chemokine measurements in the sputum supernatants in COPD. Sputum IL-5 was associated with a sputum eosinophilia and was attenuated following oral corticosteroid therapy. Whether this cytokine is important in the pathogenesis of COPD in a subgroup of patients warrants further investigation.

Carbocysteine: clinical experience and new perspectives in the treatment of chronic inflammatory diseases

BACKGROUND

Carbocysteine is a muco-active drug with free radical scavenging and anti-inflammatory properties. It is actually approved for clinical use as adjunctive therapy of respiratory tract disorders characterized by excessive, viscous mucus, including chronic obstructive airways disease (COPD).

OBJECTIVE

The intriguing antioxidant and anti-inflammatory properties of carbocysteine, beyond its known mucolytic activity, are described to explain its therapeutic efficacy and suggest new clinical uses.

METHODS

After reviewing physiology and preclinical studies, human studies on the use of carbocysteine in chronic inflammatory diseases, i.e., COPD and cancer cachexia, are reviewed.

RESULTS/CONCLUSIONS

Carbocysteine has been recently recognized as an effective and safe treatment for the long-term management of COPD, able to reduce the incidence of exacerbations and improve patient quality of life. Moreover, carbocysteine was effective in counteracting some symptoms associated with cancer cachexia. Preclinical and clinical studies have demonstrated that the antioxidant and anti-inflammatory properties of carbocysteine are more important than mucolysis itself for its therapeutic efficacy. Therefore, carbocysteine may be able to reverse the oxidative stress associated with several chronic inflammatory diseases, such as cardiovascular diseases and neurodegenerative disorders. Controlled, randomized studies in humans are warranted.

[Chronic obstructive pulmonary disease in patients with acute symptomatic pulmonary embolism]

BACKGROUND

The diagnosis of pulmonary embolism (PE) is often complicated by the presence of chronic obstructive pulmonary disease (COPD). Some studies have suggested that patients with PE and concomitant COPD have a worse prognosis than patients without COPD.

PATIENTS AND METHODS

Outpatients diagnosed with acute symptomatic PE at a university tertiary care hospital were prospectively included in the study. Clinical characteristics, time between onset of symptoms and diagnosis, and outcome were analyzed according to presence or absence of COPD. The primary endpoint was all-cause deaths at 3 months.

RESULTS

Of 882 patients with a confirmed diagnosis of acute symptomatic PE, 8% (95% confidence interval [CI], 6%-9%) had COPD. Patients with COPD were significantly more likely to have a delay in diagnosis of more than 3 days and to have a low pretest probability of pulmonary embolism according to a standardized clinical score. The total number of deaths during 3 months of follow-up was 128 (14%; 95% CI, 12%-17%). Factors significantly associated with mortality from all causes were a history of cancer or immobilization, systolic blood pressure less than 100mm Hg, and arterial oxyhemoglobin saturation less than 90%. COPD was significantly associated with PE-related death in the logistic regression analysis (relative risk, 2.2; 95% CI, 1.0-5.1).

CONCLUSIONS

Patients with COPD and PE more often have a lower pretest probability and a longer delay in diagnosis of PE. COPD is significantly associated with PE-related death in the 3 months following diagnosis.

Should FEV1/FEV6 replace FEV1/FVC ratio to detect airway obstruction? A metaanalysis

BACKGROUND

The conventional FEV(1)/FVC test is the "gold standard" to quantitate airway obstruction, but elderly subjects or patients with severe respiratory diseases quite frequently cannot make such an effort. Many studies have investigated the usefulness of FEV(1)/forced expired volume in 6 s (FEV(6)) measurements as an alternative for FEV(1)/FVC for diagnosis of airway obstruction. We conducted a meta-analysis to determine the FEV(1)/FEV(6) substitute for FEV(1)/FVC in the diagnosis of airway obstruction.

METHODS

After a systematic review of all-language studies, sensitivity, specificity, and other measures of accuracy of FEV(1)/FEV(6) in the diagnosis of airway obstruction were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall test performance.

RESULTS

Eleven studies met our inclusion criteria. The summary estimates for FEV(1)/FEV(6) in the diagnosis of airway obstruction in the studies included were as follows: sensitivity, 0.89 (95% confidence interval [CI], 0.83 to 0.93); specificity, 0.98 (95% CI, 0.95 to 0.99); positive likelihood ratio, 45.46 (95% CI, 18.26 to 113.21); negative likelihood ratio, 0.11 (95% CI, 0.08 to 0.17); diagnostic odds ratio, 396.02 (95% CI, 167.32 to 937.31); and diagnostic score, 5.98 (95% CI, 5.12 to 6.84).

CONCLUSIONS

FEV(1)/FEV(6) is a sensitive and specific test for the diagnosis of airway obstruction. FEV(1)/FEV(6) can be used as a valid alternative for FEV(1)/FVC in the diagnosis of airway obstruction.

Chronic obstructive pulmonary disease is an independent predictor of death but not atherosclerotic events in patients with myocardial infarction: analysis of the Valsartan in Acute Myocardial Infarction Trial (VALIANT)

AIMS

Chronic obstructive pulmonary disease is an independent predictor of mortality in patients with myocardial infarction (MI). However, the impact on mode of death and risk of atherosclerotic events is unknown.

METHODS AND RESULTS

We assessed the risk of death and major cardiovascular (CV) events associated with chronic obstructive pulmonary disease in 14 703 patients with acute MI enrolled in the Valsartan in Acute Myocardial Infarction (VALIANT) trial. Cox proportional hazards models were used to evaluate the relationship between chronic obstructive pulmonary disease and CV outcomes. A total of 1258 (8.6%) patients had chronic obstructive pulmonary disease. Over a median follow-up period of 24.7 months, all-cause mortality was 30% in patients with chronic obstructive pulmonary disease, compared with 19% in those without. The adjusted hazard ratio (HR) for mortality was 1.14 (95% confidence interval 1.02-1.28). This reflected increased incidence of both non-CV death [HR 1.86 (1.43-2.42)] and sudden death [HR 1.26 (1.03-1.53)]. The unadjusted risk of all pre-specified CV outcomes was increased. However, after multivariate adjustment, chronic obstructive pulmonary disease was not an independent predictor of atherosclerotic events [MI or stroke: HR 0.98 (0.77-1.23)]. Mortality was significantly lower in patients receiving beta-blockers, irrespective of airway disease.

CONCLUSION

In high-risk patients with acute MI, chronic obstructive pulmonary disease is associated with increased mortality and non-fatal clinical events (both CV and non-CV). However, patients with chronic obstructive pulmonary disease did not experience a higher rate of atherosclerotic events.

24-hour bronchodilator efficacy of single doses of indacaterol in subjects with COPD: comparison with placebo and formoterol

OBJECTIVE

To assess the bronchodilator efficacy, safety and tolerability of indacaterol, a novel, once-daily inhaled beta(2)-agonist bronchodilator, in patients with chronic obstructive pulmonary disease (COPD).

METHODS

This crossover, double-blind, double-dummy study was conducted to evaluate the 24-h bronchodilator effect of a range of single doses of indacaterol (150 microg, 300 microg and 600 microg), given in the morning via single-dose dry powder inhaler (SDDPI) in subjects with COPD, compared with placebo and with the daily therapeutic dose of formoterol (two 12 microg doses 12 h apart, via an SDDPI). Tolerability and safety were also assessed.

RESULTS

Fifty-one subjects with moderate-to-severe COPD received each of the five treatments on separate study days in randomised sequence. The 24-h trough FEV(1) (primary endpoint; mean [95% CI]) was 1.46 (1.43, 1.49) L with indacaterol 600 microg (p < 0.001 vs. placebo, p < 0.01 vs. formoterol, p < 0.05 vs. indacaterol 150 microg), 1.45 (1.42, 1.48) L with indacaterol 300 microg (p < 0.001 vs. placebo, p < 0.05 vs. formoterol), 1.42 (1.39, 1.45) L with indacaterol 150 microg (p < 0.001 vs. placebo), 1.41 (1.38, 1.43) L with formoterol (p < 0.001 vs. placebo) and 1.28 (1.25, 1.31) L with placebo. All treatments were well tolerated and there was little effect on serum potassium, blood glucose or QTc interval.

CONCLUSION

All doses of indacaterol were effective in providing 24-h bronchodilation and were well-tolerated in subjects with COPD. The bronchodilator efficacy of indacaterol (150, 300 and 600 microg) at 24 h post-dose was at least as efficacious as formoterol 12 microg twice daily.

Nrf2-dependent sulfiredoxin-1 expression protects against cigarette smoke-induced oxidative stress in lungs

Oxidative stress results in protein oxidation and is involved in the pathogenesis of lung diseases such as chronic obstructive pulmonary disorder (COPD). Sulfiredoxin-1 (Srx1) catalyzes the reduction of cysteine sulfinic acid to sulfenic acid in oxidized proteins and protects them from inactivation. This study examined the mechanism of transcriptional regulation of Srx1 and its possible protective role during oxidative stress associated with COPD. Nrf2, a transcription factor known to influence susceptibility to pulmonary diseases, upregulates Srx1 expression during oxidative stress caused by cigarette smoke exposure in the lungs of mice. Disruption of Nrf2 signaling by genetic knockout in mice or RNAi in cells downregulated the expression of Srx1. In silico analysis of the 5'-promoter-flanking region of Srx1 identified multiple antioxidant-response elements (AREs) that are highly conserved. Reporter and chromatin-immunoprecipitation assays demonstrated that ARE1 at -228 is critical for the Nrf2-mediated response. Attenuation of Srx1 expression with RNAi potentiated the toxicity of hydrogen peroxide (H2O2), whereas overexpression of Srx1 protected against H2O2-mediated cell death in vitro. Immunoblot analysis revealed dramatic decreases in Srx1 expression in lungs from patients with COPD relative to nonemphysematous lungs together with a decline in Nrf2 protein. Thus, Srx1, a key Nrf2-regulated gene, contributes to protection against oxidative injury in the lung.

Inhaled drugs to reduce exacerbations in patients with chronic obstructive pulmonary disease: a network meta-analysis

BACKGROUND

Most patients with chronic obstructive pulmonary disease (COPD) receive inhaled long-acting bronchodilators and inhaled corticosteroids. Conventional meta-analyses established that these drugs reduce COPD exacerbations when separately compared with placebo. However, there are relatively few head-to-head comparisons and conventional meta-analyses focus on single comparisons rather than on a simultaneous analysis of competing drug regimens that would allow rank ordering of their effectiveness. Therefore we assessed, using a network meta-analytic technique, the relative effectiveness of the common inhaled drug regimes used to reduce exacerbations in patients with COPD.

METHODS

We conducted a systematic review and searched existing systematic reviews and electronic databases for randomized trials of >/= 4 weeks' duration that assessed the effectiveness of inhaled drug regimes on exacerbations in patients with stable COPD. We extracted participants and intervention characteristics from included trials and assessed their methodological quality. For each treatment group we registered the proportion of patients with >/= 1 exacerbation during follow-up. We used treatment-arm based logistic regression analysis to estimate the absolute and relative effects of inhaled drug treatments while preserving randomization within trials.

RESULTS

We identified 35 trials enrolling 26,786 patients with COPD of whom 27% had >/= 1 exacerbation. All regimes reduced exacerbations statistically significantly compared with placebo (odds ratios ranging from 0.71 (95% confidence interval [CI] 0.64 to 0.80) for long-acting anticholinergics to 0.78 (95% CI 0.70 to 0.86) for inhaled corticosteroids). Compared with long-acting bronchodilators alone, combined treatment was not more effective (comparison with long-acting beta-agonists: odds ratio 0.93 [95% CI 0.84 to 1.04] and comparison with long-acting anticholinergics: odds ratio 1.02 [95% CI 0.90 to 1.16], respectively). If FEV1 was </= 40% predicted, long-acting anticholinergics, inhaled corticosteroids, and combination treatment reduced exacerbations significantly compared with long-acting beta-agonists alone, but not if FEV1 was > 40% predicted. This effect modification was significant for inhaled corticosteroids (P = 0.02 for interaction) and combination treatment (P = 0.01) but not for long-acting anticholinergics (P = 0.46). A limitation of this analysis is its exclusive focus on exacerbations and lack of FEV1 data for individual patients.

CONCLUSION

We found no evidence that one single inhaled drug regimen is more effective than another in reducing exacerbations. Inhaled corticosteroids when added to long-acting beta-agonists reduce exacerbations only in patients with COPD with FEV1 </= 40%.

COPD as a lung disease with systemic consequences--clinical impact, mechanisms, and potential for early intervention

The natural course of chronic obstructive pulmonary disease (COPD) is complicated by the development of systemic consequences and co-morbidities. These may be major features in the clinical presentation of COPD, prompting increasing interest. Systemic consequences may be defined as non-pulmonary manifestations of COPD with an immediate cause-and-effect relationship, whereas co-morbidities are diseases associated with COPD. The major systemic consequences/co-morbidities now recognized are: deconditioning, exercise intolerance, skeletal muscle dysfunction, osteoporosis, metabolic impact, anxiety and depression, cardiovascular disease, and mortality. The mechanisms by which these develop are unclear. Probably many factors are involved. Two appear of paramount importance: systemic inflammation, which presents in some patients with stable disease and virtually all patients during exacerbations, and inactivity, which may be a key link to most COPD-related co-morbidities. Further studies are required to determine the role of inflammatory cells/mediators involved in systemic inflammatory processes in causing co-morbidities; the link between activity and co-morbidities; and how COPD therapy may affect activity. Both key mechanisms appear to be influenced significantly by COPD exacerbations. Importantly, although the prevalence of systemic consequences increases with increasing severity of airflow obstruction, both systemic consequences and co-morbidities are already present in the Global Initiative for Chronic Obstructive Lung Disease Stage II. This supports the concept of early intervention in chronic obstructive pulmonary disease. Although at present early intervention studies in COPD are lacking, circumstantial evidence suggests that current treatments may influence events leading to the systemic consequences and co-morbidities, and thus may affect the clinical manifestations of the disease.

Anxiety and depression in COPD: current understanding, unanswered questions, and research needs

BACKGROUND

Approximately 60 million people in the United States live with one of four chronic conditions: heart disease, diabetes, chronic respiratory disease, and major depression. Anxiety and depression are very common comorbidities in COPD and have significant impact on patients, their families, society, and the course of the disease.

METHODS

We report the proceedings of a multidisciplinary workshop on anxiety and depression in COPD that aimed to shed light on the current understanding of these comorbidities, and outline unanswered questions and areas of future research needs.

RESULTS

Estimates of prevalence of anxiety and depression in COPD vary widely but are generally higher than those reported in some other advanced chronic diseases. Untreated and undetected anxiety and depressive symptoms may increase physical disability, morbidity, and health-care utilization. Several patient, physician, and system barriers contribute to the underdiagnosis of these disorders in patients with COPD. While few published studies demonstrate that these disorders associated with COPD respond well to appropriate pharmacologic and nonpharmacologic therapy, only a small proportion of COPD patients with these disorders receive effective treatment.

CONCLUSION

Future research is needed to address the impact, early detection, and management of anxiety and depression in COPD.

Risk for death associated with medications for recently diagnosed chronic obstructive pulmonary disease

BACKGROUND

Concerns exist regarding increased risk for mortality associated with some chronic obstructive pulmonary disease (COPD) medications.

OBJECTIVE

To examine the association between various respiratory medications and risk for death in veterans with newly diagnosed COPD.

DESIGN

Nested case-control study in a cohort identified between 1 October 1999 and 30 September 2003 and followed through 30 September 2004 by using National Veterans Affairs inpatient, outpatient, pharmacy, and mortality databases; Centers for Medicare & Medicaid Services databases; and National Death Index Plus data. Cause of death was ascertained for a random sample of 40% of those who died during follow-up. Case patients were categorized on the basis of all-cause, respiratory, or cardiovascular death. Mortality risk associated with medications was assessed by using conditional logistic regression adjusted for comorbid conditions, health care use, and markers of COPD severity.

SETTING

U.S. Veterans Health Administration health care system.

PARTICIPANTS

32 130 case patients and 320 501 control participants in the all-cause mortality analysis. Of 11 897 patients with cause-of-death data, 2405 case patients had respiratory deaths and 3159 case patients had cardiovascular deaths.

MEASUREMENTS

All-cause mortality; respiratory and cardiovascular deaths; and exposure to COPD medications, inhaled corticosteroids, ipratropium, long-acting beta-agonists, and theophylline in the 6 months preceding death.

RESULTS

Adjusted odds ratios (ORs) for all-cause mortality were 0.80 (95% CI, 0.78 to 0.83) for inhaled corticosteroids, 1.11 (CI, 1.08 to 1.15) for ipratropium, 0.92 (CI, 0.88 to 0.96) for long-acting beta-agonists, and 1.05 (CI, 0.99 to 1.10) for theophylline. Ipratropium was associated with increased cardiovascular deaths (OR, 1.34 [CI, 1.22 to 1.47]), whereas inhaled corticosteroids were associated with reduced risk for cardiovascular death (OR, 0.80 [CI, 0.72 to 0.88]). Results were consistent across sensitivity analyses.

LIMITATIONS

Current smoking status and lung function were not measured. Misclassification of cause-specific mortality is unknown.

CONCLUSION

The possible association between ipratropium and elevated risk for all-cause and cardiovascular death needs further study.

Decline in NRF2-regulated antioxidants in chronic obstructive pulmonary disease lungs due to loss of its positive regulator, DJ-1

RATIONALE

Oxidative stress is a key contributor in chronic obstructive pulmonary disease (COPD) pathogenesis caused by cigarette smoking. NRF2, a redox-sensitive transcription factor, dissociates from its inhibitor, KEAP1, to induce antioxidant expression that inhibits oxidative stress.

OBJECTIVES

To determine the link between severity of COPD, oxidative stress, and NRF2-dependent antioxidant levels in the peripheral lung tissue of patients with COPD.

METHODS

We assessed the expression of NRF2, NRF2-dependent antioxidants, regulators of NRF2 activity, and oxidative damage in non-COPD (smokers and former smokers) and smoker COPD lungs (mild and advanced). Cigarette smoke-exposed human lung epithelial cells (Beas2B) and mice were used to understand the mechanisms.

MEASUREMENTS AND MAIN RESULTS

When compared with non-COPD lungs, the COPD patient lungs showed (1) marked decline in NRF2-dependent antioxidants and glutathione levels, (2) increased oxidative stress markers, (3) significant decrease in NRF2 protein with no change in NRF2 mRNA levels, and (4) similar KEAP1 but significantly decreased DJ-1 levels (a protein that stabilizes NRF2 protein by impairing KEAP1-dependent proteasomal degradation of NRF2). Exposure of Bea2B cells to cigarette smoke caused oxidative modification and enhanced proteasomal degradation of DJ-1 protein. Disruption of DJ-1 in mouse lungs, mouse embryonic fibroblasts, and Beas2B cells lowered NRF2 protein stability and impaired antioxidant induction in response to cigarette smoke. Interestingly, targeting KEAP1 by siRNA or the small-molecule activator sulforaphane restored induction of NRF2-dependent antioxidants in DJ-1-disrupted cells in response to cigarette smoke.

CONCLUSIONS

NRF2-dependent antioxidants and DJ-1 expression was negatively associated with severity of COPD. Therapy directed toward enhancing NRF2-regulated antioxidants may be a novel strategy for attenuating the effects of oxidative stress in the pathogenesis of COPD.

Effects of 3-week outpatient pulmonary rehabilitation on exercise capacity, dyspnea, and quality of life in COPD

The effects of intensive 3-week outpatient pulmonary rehabilitation (PR) on exercise capacity, dyspnea, and health-related quality of life (HRQL) were investigated in patients with COPD. Two hundred ten patients with COPD (mean FEV(1) = 54%pred) underwent PR consisting of exercise training, patient and psychosocial education, breathing and relaxation therapy, nutrition counseling, and smoking cessation support. Before and after PR, exercise capacity was assessed with 6-min walking tests (6MWT) and constant cycle ergometer exercise (CEE). Dyspnea was measured after 6MWTs with a Borg scale and after PR with the Transition Dyspnoea Index (TDI). HRQL was examined with the Medical Outcomes Study Short Form 36 (SF-36). Results showed improvements in the 6MWT (+39 m, p < 0.001) and CEE (+241 W x min, p < 0.001) after PR, paralleled by decreased dyspnea during the 6MWT (-0.5, p < 0.001) and during activities (TDI score = 3.6). Increases in all SF-36 subscales reflected improved HRQL after PR (p < 0.001). No gender differences were found. Patients with milder versus more severe COPD improved similarly in most outcomes. Regression analyses revealed that TDI scores were the most important predictor of improvements in HRQL. The results suggest that intensive 3-week outpatient PR is associated with improvements in exercise capacity, dyspnea, and HRQL in male and female patients with COPD irrespective of COPD severity. Reduced dyspnea during activities contributed the most to improvements in HRQL.

Polarized localization of epithelial CXCL11 in chronic obstructive pulmonary disease and mechanisms of T cell egression

The exit of lymphocytes from the interstitium of the lung, across the bronchial epithelium and into the airway lumen, is known as egression, or luminal clearance. Egression is important for immune surveillance and the resolution of inflammation, but the mechanisms involved are unknown. We show that egression of human T cells across the bronchial epithelium is a multistep process, driven in part by a polarized transepithelial gradient of CXCL11 that is up-regulated in patients with chronic obstructive airways disease. Previous studies have shown that T cells can migrate across a disrupted bronchial epithelium, but we provide evidence that egression does not require epithelial injury, and can take place across an intact epithelial barrier. After negotiating the extracellular matrix, the T cell adheres to the basal surface of the bronchial epithelial cell using alpha(4) and leukocyte function associated-1 integrins before crossing the epithelium in an leukocyte function associated-1-dependent way. We demonstrate an egression-dependent decrease in transepithelial resistance across the epithelium without gross alteration in tight-junction proteins. The process of egression has been relatively overlooked when considering the control of leukocyte trafficking in the lung and other epithelial organs. This study highlights the role of the respiratory epithelium in the trafficking of T lymphocytes from the pulmonary interstitium and into the large airways, during the onset and resolution of pulmonary inflammation.

Chronic obstructive pulmonary disease in the older patient

Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases in the world. It is a major cause of morbidity, mortality, and health care use, particularly in older adults. In the following sections, the authors review the diagnosis and management of COPD with a focus on special issues in older adults.

The impact of inhaled corticosteroid and long-acting beta-agonist combination therapy on outcomes in COPD

Chronic obstructive pulmonary disease (COPD) is an under-recognized cause of morbidity and mortality worldwide that imposes an ever increasing burden on the patient and society alike. The disease encompasses multiple structural and functional components of which inflammation is at the core of the disease, affecting the lungs and other organs. Consequently, current treatment strategies are aimed at treating both the symptoms and the pulmonary inflammation underlying the complex pathophysiology of COPD. Smoking cessation is the only intervention currently shown to slow disease progression in COPD and decrease all-cause mortality, aside from lung transplant, lung-volume reduction surgery and oxygen therapy in selective patients. However, this intervention is difficult to achieve and sustain because of the addictive and chronic relapsing nature of cigarette smoking. Pharmacotherapy with bronchodilating agents, including the beta 2-agonists, anticholinergics and methylxanthines, is central to the symptomatic management of all stages of COPD. While inhaled corticosteroids (ICS) are employed to reduce inflammation in more severe patients, their role as stand alone medication in COPD is not well defined. However, increasing evidence suggests that long-acting beta 2-agonists (LABAs) and ICS have complementary and synergistic effects, when delivered as combination therapy from a single inhaler. In this respect, two preparations comprising combinations of salmeterol+fluticasone propionate (SFC) and formoterol+budesonide (FBC) are currently available and employed for treatment of more severe disease. Several large-scale studies in patients with moderate-to-severe COPD have demonstrated that treatment with SFC and FBC leads to significantly greater improvements in lung function, exacerbations, health status and breathlessness, compared with placebo or monotherapy with the component drugs. In the recently published landmark study, Towards a Revolution in COPD Health (TORCH), regular treatment with SFC narrowly missed demonstrating a statistically significant benefit on the reduction in all-cause mortality over 3 years (17.5% reduction in risk, P=0.052), further emphasizing the clinical usefulness of LABA+ICS therapy in COPD. In view of this increasing evidence for the additional effectiveness of LABA+ICS combinations compared with the individual components, and the potential benefits of LABA+ICS on lung function, disease progression and potentially on all-cause mortality, initiation of LABA+ICS combination treatment early in the COPD disease process may be warranted.

SEARCH STRATEGY

The studies discussed in this review were identified from systematic searches of Medline and the Cochrane Database, up to October 2007, for articles in English or with English abstracts describing randomized, double-blind, parallel-group/crossover trials of at least 24 weeks' duration. All searches were performed using the terms: chronic obstructive pulmonary disease, COPD, chronic obstructive airway disease, or COAD AND either salmeterol, formoterol, long-acting beta 2-adrenoceptor agonist, fluticasone propionate, budesonide, inhaled corticosteroids, or inhaled glucocorticosteroids. Additional relevant references were identified from the reference lists of selected papers. Only studies that compared a combined LABA+ICS therapy with its monotherapy components were selected for inclusion in this manuscript.

A Holy Grail of asthma management: toward understanding how long-acting beta(2)-adrenoceptor agonists enhance the clinical efficacy of inhaled corticosteroids

There is unequivocal evidence that the combination of an inhaled corticosteroid (ICS) -- i.e. glucocorticoid -- and an inhaled long-acting beta(2)-adrenoceptor agonist (LABA) is superior to each component administered as a monotherapy alone in the clinical management of asthma. Moreover, Calverley and colleagues (Lancet 2003, 361: 449-456; N Engl J Med 2007, 356: 775-789) reporting for the 'TRial of Inhaled STeroids ANd long-acting beta(2)-agonists (TRISTAN)' and 'TOwards a Revolution in COPD Health (TORCH)' international study groups also demonstrated the superior efficacy of LABA/ICS combination therapies over ICS alone in the clinical management of chronic obstructive pulmonary disease. This finding has been independently confirmed indicating that the therapeutic benefit of LABA/ICS combination therapies is not restricted to asthma and may be extended to other chronic inflammatory diseases of the airways. Despite the unquestionable benefit of LABA/ICS combination therapies, there is a vast gap in our understanding of how these two drugs given together deliver superior clinical efficacy. In this article, we review the history of LABA/ICS combination therapies and critically evaluate how these two classes of drugs might interact at the biochemical level to suppress pro-inflammatory responses. Understanding the molecular basis of this fundamental clinical observation is a Holy Grail of current respiratory diseases research as it could permit the rational exploitation of this effect with the development of new 'optimized' LABA/ICS combination therapies.

Is combination therapy with inhaled anticholinergics and beta2-adrenoceptor agonists justified for chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease (COPD) is a debilitating condition characterised by progressive, irreversible airflow limitation. The economic and social burden of the disease is enormous. The treatment of COPD is guided by the stage of the disease and is aimed primarily at control of symptoms. Bronchodilators are the cornerstone of pharmacological management of COPD. Short-acting bronchodilators (beta(2)-adrenoceptor agonists and anticholinergics) have been available for many years and have been extensively studied as individual agents and in combination. When administered in combination, short-acting bronchodilators provide superior bronchodilation compared with individual agents given alone. However, the improvement in bronchodilation does not translate into an improvement in quality-of-life (QOL) indices. More recently, long-acting beta(2)-adrenoceptor agonists (LABAs) and anticholinergics have been introduced, and current guidelines recommend regular use of these agents in COPD of Global initiative for chronic Obstructive Lung Disease (GOLD) stage II or more. Combining short-acting anticholinergics with LABAs for daily use has been evaluated, but this combination does not confer any advantage in terms of subjective improvement or prevention of exacerbations. Combining the long-acting anticholinergic tiotropium bromide with formoterol given once or twice daily improves airway obstruction and hyperinflation. However, the effects of combinations of long-acting bronchodilators on patients' symptom scores, QOL and exacerbations remain to be studied. Ultra-LABAs, which are in development, may enable use of a combination of long-acting bronchodilators in a single inhaler for once-daily use, thus simplifying the regimen. This article discusses the results of various clinical trials comparing the efficacy of bronchodilators given alone or in combination to patients with COPD, with emphasis on the effects of these agents on bronchodilation, symptomatic and objective improvements in QOL and prevention of exacerbations.

COPD prevalence in a random population survey: a matter of definition

A recent American Thoracic Society and European Respiratory Society joint Task Force report recommends using a lower limit of normal (LLN) of forced expiratory volume in one second/forced vital capacity as opposed to a fixed ratio of <0.7 to diagnose airflow obstruction, in order to reduce false positive diagnoses of chronic obstructive pulmonary disease (COPD) as defined by the Global Initiative for Obstructive Lung Disease (GOLD). To date, there is no reliable spirometry-based prevalence data for COPD in New Zealand and the effect of different definitions of airflow obstruction based on post-bronchodilator spirometry is not known. Detailed written questionnaires, full pulmonary function tests (including pre- and post-bronchodilator flow-volume loops) and atopy testing were completed in 749 subjects recruited from a random population sample. The GOLD-defined, age-adjusted prevalence (95% confidence interval) for adults aged >or=40 yrs was 14.2 (11.0-17.0)% compared with an LLN-defined, age-adjusted, post-bronchodilator prevalence in the same group of 9.0 (6.7-11.3)%. The prevalence of chronic obstructive pulmonary disease varied markedly depending on the definition used. Further research using longitudinal rather than cross-sectional data will help decide the preferred approach in chronic obstructive pulmonary disease prevalence surveys.

Model for estimating the population prevalence of chronic obstructive pulmonary disease: cross sectional data from the Health Survey for England

Background

Chronic obstructive pulmonary disease (COPD) is a major but neglected public health problem. Currently 1.4% of the England population has a clinical diagnosis of COPD, but the true burden of the disease has not been known with certainty, as many cases remain undiagnosed.

Methods

A mathematical model based on cross sectional data from a representative sample of the population in England (the Heath Survey for England 2001, n = 10,750) was developed allowing estimates on the prevalence of COPD (defined based on the presence of airflow obstruction) to be obtained. Logistic regression analysis was used to investigate and choose risk factors for inclusion in the model and to derive the prevalence estimates based on the strength of association between selected risk factors and the outcome COPD. The model allows the prevalence to be estimated in populations at national level and also at regional and large local areas, based on their compositions according to age, sex, smoking and ethnicity, and on area degrees of urbanisation and deprivation. We applied the model to measure the prevalence of COPD in England and in some sub-groups of the population within the country.

Results

The prevalence of COPD in England is estimated as 3.1% (3.9% in men and 2.4% in women) in the population over 15 years of age, and 5.3% (6.8% in men and 3.9% in women) in 45 year-olds and over. There was a 7-fold variation in the prevalence across subgroups of the population, with lowest values in Asian women from wealthy rural areas (1.7%), and highest in black men from deprived urban areas (12.5%).

Conclusion

The model can be used to estimate population prevalence of COPD from large general practices to national level, and as a tool to identify areas of high levels of unmet needs for COPD priority health actions. The results from the model highlight the importance of including variables other than age, sex and smoking, i.e. levels of deprivation, urbanisation and ethnicity, when estimating population prevalence of COPD. The model should be validated at local level and incorporated into case-finding strategies.

Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary

Chronic obstructive pulmonary disease (COPD) remains a major public health problem. It is the fourth leading cause of chronic morbidity and mortality in the United States, and is projected to rank fifth in 2020 in burden of disease worldwide, according to a study published by the World Bank/World Health Organization. Yet, COPD remains relatively unknown or ignored by the public as well as public health and government officials. In 1998, in an effort to bring more attention to COPD, its management, and its prevention, a committed group of scientists encouraged the U.S. National Heart, Lung, and Blood Institute and the World Health Organization to form the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Among the important objectives of GOLD are to increase awareness of COPD and to help the millions of people who suffer from this disease and die prematurely of it or its complications. The first step in the GOLD program was to prepare a consensus report, Global Strategy for the Diagnosis, Management, and Prevention of COPD, published in 2001. The present, newly revised document follows the same format as the original consensus report, but has been updated to reflect the many publications on COPD that have appeared. GOLD national leaders, a network of international experts, have initiated investigations of the causes and prevalence of COPD in their countries, and developed innovative approaches for the dissemination and implementation of COPD management guidelines. We appreciate the enormous amount of work the GOLD national leaders have done on behalf of their patients with COPD. Despite the achievements in the 5 years since the GOLD report was originally published, considerable additional work is ahead of us if we are to control this major public health problem. The GOLD initiative will continue to bring COPD to the attention of governments, public health officials, health care workers, and the general public, but a concerted effort by all involved in health care will be necessary.

International variation in the prevalence of COPD (the BOLD Study): a population-based prevalence study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a growing cause of morbidity and mortality worldwide, and accurate estimates of the prevalence of this disease are needed to anticipate the future burden of COPD, target key risk factors, and plan for providing COPD-related health services. We aimed to measure the prevalence of COPD and its risk factors and investigate variation across countries by age, sex, and smoking status.

METHODS

Participants from 12 sites (n=9425) completed postbronchodilator spirometry testing plus questionnaires about respiratory symptoms, health status, and exposure to COPD risk factors. COPD prevalence estimates based on the Global Initiative for Chronic Obstructive Lung Disease staging criteria were adjusted for the target population. Logistic regression was used to estimate adjusted odds ratios (ORs) for COPD associated with 10-year age increments and 10-pack-year (defined as the number of cigarettes smoked per day divided by 20 and multiplied by the number of years that the participant smoked) increments. Meta-analyses provided pooled estimates for these risk factors.

FINDINGS

The prevalence of stage II or higher COPD was 10.1% (SE 4.8) overall, 11.8% (7.9) for men, and 8.5% (5.8) for women. The ORs for 10-year age increments were much the same across sites and for women and men. The overall pooled estimate was 1.94 (95% CI 1.80-2.10) per 10-year increment. Site-specific pack-year ORs varied significantly in women (pooled OR=1.28, 95% CI 1.15-1.42, p=0.012), but not in men (1.16, 1.12-1.21, p=0.743).

INTERPRETATION

This worldwide study showed higher levels and more advanced staging of spirometrically confirmed COPD than have typically been reported. However, although age and smoking are strong contributors to COPD, they do not fully explain variations in disease prevalence-other factors also seem to be important. Although smoking cessation is becoming an increasingly urgent objective for an ageing worldwide population, a better understanding of other factors that contribute to COPD is crucial to assist local public-health officials in developing the best possible primary and secondary prevention policies for their regions.

Global burden of COPD: risk factors, prevalence, and future trends

Chronic obstructive pulmonary disease (COPD) continues to be an important cause of morbidity, mortality, and health-care costs worldwide. It is a global health issue, with cigarette smoking being an important risk factor universally; other factors, such as exposure to indoor and outdoor air pollution, occupational hazards, and infections, are also important. As the global population ages, the burden of COPD will increase in years to come. Prevalence estimates of the disorder show considerable variability across populations, suggesting that risk factors can affect populations differently. Other advances in our understanding of COPD are increased recognition of the importance of comorbid disease, identification of different COPD phenotypes, and understanding how factors other than lung function affect outcome in our patients. The challenge we will all face in the next few years will be implementation of cost-effective prevention and management strategies to stem the tide of this disease and its cost.

Impact of protein acetylation in inflammatory lung diseases

Chronic inflammatory lung diseases are characterized by increased expression of multiple inflammatory genes following activation by proinflammatory transcription factors, such as nuclear factor kappaB (NF-kappaB) and AP-1. Gene expression is, at least in part, regulated by acetylation of core histones through the action of coactivators, such as CREB-binding protein (CBP), which have intrinsic histone acetyltransferase (HAT) activity. Conversely gene repression is mediated via a combination of histone deacetylases (HDAC) and other corepressors. In asthma, the level of HAT activity is elevated in bronchial biopsies, whereas HDAC activity levels are only partially reduced and inhaled corticosteroids are able to reduce the increased HAT activity back to those seen in normal subjects. In contrast, in chronic obstructive pulmonary disease (COPD), there is a greater reduction in HDAC activity and HDAC2 expression but no difference in HAT activity. HAT and HDAC are also reported to modify a large and expanding number of nonhistone proteins, including nuclear import proteins, chaperones, cytoskeletal proteins, and other transcriptional factors, such as NF-kappaB and signal transducer and activation of transcription (STAT). Acetylation regulates several aspects of protein function and stability leading to differing effects on inflammatory gene expression and cell recruitment involved in the pathogenesis of inflammatory diseases. This review will examine the impact of acetylation on the function of key proteins involved in airway inflammatory disease and the effects of current therapies on acetylation status of key proteins. Further appreciation of the role of these changes may lead to the development of novel therapeutic approaches to inflammatory lung diseases that are currently difficult to treat.