Systemic manifestations and comorbidities of COPD

Treatment of COPD: moving beyond the lungs

We still do not know whether the successful treatment of the comorbid diseases associated with COPD, mainly cardiovascular disease, also positively influences the course of the lung disease because so far there are few definite data documenting that treatment of COPD comorbidities will reduce morbidity and mortality rates in these patients. Observational studies suggest that COPD patients treated with statins, angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers, and β-adrenoceptor blockers may have improved survival and reduced hospitalisation from exacerbations. Progress in basic and translational research has led to a better understanding of pharmacological mechanisms that may explain the effects of these drugs on COPD and some small clinical trial activity is beginning to generate promising results.

Associations between BODE index and systemic inflammatory biomarkers in COPD

BACKGROUND

COPD is a multicomponent disease and systemic inflammation represents one of the possible mechanisms responsible for its systemic manifestations, including skeletal muscle weakness and cachexia. Fat-free mass index (FFMI) that reflects the skeletal muscle mass, has been shown to be associated with both dyspnoea and exercise capacity. We hypothesized that the multidimensional BODE index, that reflects the multicomponent nature of COPD, might be related to biomarkers of systemic inflammation. We further evaluated associations between FFMI and systemic inflammation.

METHODS

BODE index and FFMI were calculated in 222 stable COPD patients and 132 smokers or ex-smokers with normal lung function. Systemic inflammation was evaluated with the measurement of leptin, adiponectin, CRP, IL-6, and TNF-α in serum samples of COPD patients.

RESULTS

In patients with COPD, both BODE index and FFMI presented significant positive and negative associations respectively with leptin levels (R(2) 0.61 and 0.65, respectively), whereas FFMI presented an additional negative association with the levels of TNF-α (R(2) 0.38). No significant associations were observed in smokers or ex-smokers with normal lung function.

CONCLUSIONS

Both BODE index and FFMI, are related to the circulating levels of leptin in patients with COPD, suggesting a possible role for leptin in the systemic component of COPD. The additional association of FFMI with TNF-α may further support a role of systemic inflammation in muscle wasting in COPD.

Effect of lipoteichoic acid on IL-2 and IL-5 release from T lymphocytes in asthma and COPD

Susceptibility to infections with gram-positive bacteria, which are an important trigger of exacerbations, is increased in COPD and asthma. Unraveling the underlying mechanisms may help developing therapeutic strategies to reduce exacerbation rates. The aim of this study was to evaluate the effects of lipoteichoic acid (LTA), a danger signal from gram-positive bacteria, on T cell cytokines related to bacterial infection defense in COPD and asthma. T cell populations within peripheral blood mononuclear cells (PBMCs) were ex-vivo activated towards T(H)2/T(C)2 subtypes and subsequently stimulated with LTA. IL-2 and IL-5 concentrations in cell culture supernatants were measured by ELISA comparative between non-smokers (NS), current smokers without airflow limitation (S), smokers with moderate to severe COPD and mild to moderate asthmatics (A) (each n=10). IL-2 and IL-5 baseline levels were without differences between the cohorts. After T cell activation, IL-2 and IL-5 releases were increased in all cohorts, however, for IL-2 this increase was significantly higher in S and by trend in COPD compared to the other groups. LTA time-dependently suppressed IL-2 release in NS, S and COPD but not in A. LTA reduced IL-5 release in COPD and A but not in NS and S. Summarized, LTA reduces T(H)2/T(C)2 cytokines indicating immunosuppressive effects, which are dysregulated in COPD and asthma. This implies a misguided response to gram-positive bacterial infections, which might help to explain the increased susceptibility to bacterial infections in COPD and asthma.

[Comorbidities in patients hospitalized due to chronic obstructive pulmonary disease. A comparative analysis of the ECCO and ESMI studies]

BACKGROUNDS AND OBJECTIVES

The presence of associated diseases is very frequent in patients hospitalized due to exacerbation of COPD. We have studied the comorbidities of patients admitted due to the disease in the Spanish Internal Medicine Services and we have evaluated the variations in regards to a previous study (ECCO study) performed two years earlier.

PATIENTS AND METHODS

A cross-sectional, multicenter and cohort study was performed. Patients hospitalized due to exacerbation of COPD in Spanish Internal Medicine Services were enrolled. All the patients were studied for the presence of comorbidity using the Charlson index and a questionnaire with relevant conditions not included in this index. Furthermore, spirometric data were collected on the duration of the disease or home treatment, among other variables.

RESULTS

A total of 1004 patients (398 in the ECCO study and 606 in the ESMI study) were studied. Of these, 89.4% were males, with mean age of 73 years (SD: 9.5 years). The patients of the ESMI study obtain higher scores on the Charlson index (3.04 vs. 2.71; P<0.01), and had a greater prevalence of ischemic heart disease (17 vs. 22.0%; P<0.05), heart failure (26.9 vs. 35.5%; P<.002), peripheral vascular disease (12.6 vs. 17.4%; P<.02), arterial hypertension (54.8 vs. 65.6%; P<.001), diabetes mellitus (29.4 vs. 37%; P<.02) and renal failure (6.5 vs. 16.8%; P<.0001).

CONCLUSIONS

This study confirms the elevated prevalence of associated diseases in patients with COPD who are admitted to the Spanish Internal Medicine Services and the increase of comorbidities.

Profiling the erythrocyte membrane proteome isolated from patients diagnosed with chronic obstructive pulmonary disease

Structural and metabolic alterations in erythrocytes play an important role in the pathophysiology of Chronic Obstructive Pulmonary Disease (COPD). Whether these dysfunctions are related to the modulation of erythrocyte membrane proteins in patients diagnosed with COPD remains to be determined. Herein, a comparative proteomic profiling of the erythrocyte membrane fraction isolated from peripheral blood of smokers diagnosed with COPD and smokers with no COPD was performed using differential (16)O/(18)O stable isotope labeling. A total of 219 proteins were quantified as being significantly differentially expressed within the erythrocyte membrane proteomes of smokers with COPD and healthy smokers. Functional pathway analysis showed that the most enriched biofunctions were related to cell-to-cell signaling and interaction, hematological system development, immune response, oxidative stress and cytoskeleton. Chorein (VPS13A), a cytoskeleton related protein whose defects had been associated with the presence of cell membrane deformation of circulating erythrocytes was found to be down-regulated in the membrane fraction of erythrocytes obtained from COPD patients. Methemoglobin reductase (CYB5R3) was also found to be underexpressed in these cells, suggesting that COPD patients may be at higher risk for developing methemoglobinemia. This article is part of a Special Issue entitled: Integrated omics.

Genetics of smoking and depression

Smoking and depression are significant public health problems with multiple etiological dimensions and outcomes. Although each condition is important by itself, they are important because they often potentiate each other. Consequently, it is also essential to understand the nature their relationship. This representative review focuses on the genetic etiology of the relationship in the context of reviewing first the epidemiology of depression and smoking, and then by exploring behavioral and molecular genetic studies, and other psychiatric and medical comorbidities. At this point, epidemiological evidence for a relationship between depression and smoking/nicotine dependence is compelling. Although behavioral genetic results differ somewhat by gender and in accordance with specific definitions of depression and smoking variables, recent studies show converging evidence for common genetic factors underlying the relationship, often in addition to non-shared environmental factors. The search for underlying genes and genetic mechanisms is at an early stage, but shows promising candidate genes and genetic approaches for future studies.

Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterised by progressive airflow obstruction that is only partly reversible, inflammation in the airways, and systemic effects or comorbities. The main cause is smoking tobacco, but other factors have been identified. Several pathobiological processes interact on a complex background of genetic determinants, lung growth, and environmental stimuli. The disease is further aggravated by exacerbations, particularly in patients with severe disease, up to 78% of which are due to bacterial infections, viral infections, or both. Comorbidities include ischaemic heart disease, diabetes, and lung cancer. Bronchodilators constitute the mainstay of treatment: β(2) agonists and long-acting anticholinergic agents are frequently used (the former often with inhaled corticosteroids). Besides improving symptoms, these treatments are also thought to lead to some degree of disease modification. Future research should be directed towards the development of agents that notably affect the course of disease.

Determination of inflammatory biomarkers in patients with COPD: a comparison of different assays

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory pulmonary disorder with systemic inflammatory manifestations that are mediated by circulating acute-phase reactants. This study compared an enzyme-linked immunosorbent assay (ELISA) to a nephelometric technique for the measurement of serum C-reactive protein (CRP) and serum amyloid A (SAA) and investigated how the choice of assay influenced the estimation of inflammation in patients with stable COPD.

Methods

CRP and SAA concentrations measured by ELISA and nephelometry in 88 patients with COPD and 45 control subjects were used to evaluate the performance of these methods in a clinical setting.

Results

With both assays, the concentrations of CRP and SAA were higher in COPD patients than in controls after adjustment for age and sex. There was a moderate correlation between the values measured by ELISA and those measured by nephelometry (logCRP: r = 0.55, p < 0.001; logSAA: r = 0.40, p < 0.001). However, the concentrations of biomarkers determined by nephelometry were significantly higher than those obtained with ELISA for CRP (mean difference = 2.7 (9.4) mg/L) and SAA (mean difference = 0.31 (14.3) mg/L).

Conclusion

Although the serum CRP and SAA concentrations measured by ELISA and nephelometry correlated well in COPD patients, the ELISA values tended to be lower for CRP and SAA when compared with nephelometric measurements. International standardization of commercial kits is required before the predictive validity of inflammatory markers for patients with COPD can be effectively assessed in clinical practice.

Association of bone mineral density with airway obstruction and emphysema

BACKGROUND

Airway obstruction and the extent of emphysema are reported to be responsible for reduced bone mineral density (BMD). Corresponding to different phenotypes of a pulmonary disease, different severity in extra pulmonary features may exist. We compared BMDs of subjects with or without airway obstruction and/or emphysema and investigated the relationships among BMD, the severity of airway obstruction, and the extent of emphysema.

METHODS

Using a university hospital database, we reviewed patients over 40 years old who performed spirometry, computed tomography of chest, and measurement of BMD of the lumbar (L) spine. According to the presence or absence of airway obstruction and/or emphysema, four groups were classified.

RESULTS

Among a total of 59 subjects, 33 (56%) had osteoporosis. The prevalence of osteoporosis in subjects with no airway obstruction and no emphysema, those with only emphysema, those with only airway obstruction, and those with both airway obstruction and emphysema were 42%, 57%, 64%, and 73%, respectively (p=0.047 by linear-by-linear association). The mean T-scores of BMD of L1 (p=0.032) and L1-4 spines were different among the four groups (p=0.034). Although the T-score of L1 BMD negatively correlated with the extent of emphysema (r=-0.275, p=0.035) and positively with each of body mass index (BMI) (r=0.520, p<0.001), forced expiratory volume in one second (FEV(1)) (r=0.330, p=0.011), FEV(1)/forced vital capacity (r=0.409, p=0.001), and forced expiratory flow at 25~75% of FVC (FEF(25-75%)) (r=0.438, p=0.0001), respectively, multiple linear regression analysis indicated that BMI (p<0.001) and FEF(25-75%) were predictive of BMD (p=0.012).

CONCLUSION

Low BMI and airway obstruction were strongly associated with reduced bone density rather than the extent of emphysema.

[COPD and lung cancer: epidemiological and biological links]

Lung cancer and chronic obstructive lung disease (COPD) are two common fatal diseases. Apart from their common link to tobacco, these two diseases are usually considered to be the result of separate distinct mechanisms. In the past 15 years, numerous studies have produced arguments in favour of a relationship between these two pathologies that goes beyond a simple addition of risk factors. At the epidemiological level, there are data that demonstrate an increased incidence of bronchial carcinoma in patients with COPD. The links between these two pathologies are still unexplained but there are numerous arguments supporting a common physiopathology. Common genetic and epigenetic abnormalities, mechanical factors and signalisation pathways have been quoted. COPD and lung cancer appear to be two diseases possessing a genetic basis that creates a predisposition to environmental or toxic assaults, resulting in a different clinical manifestation in each disease. Consequently, improvements in the management of these two diseases will involve a more intensive investigation of their physiopathology, and require a closer collaboration between research centres and clinical units.

Developing the model of pulmonary rehabilitation for chronic heart failure

Patients with chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF) commonly suffer from exertional symptoms of breathlessness and fatigue. The similar systemic manifestations of the conditions, including skeletal muscle dysfunction, are a major contributing factor to the limitation in exercise capacity. A period of exercise training has been shown to improve exercise performance and health-related quality of life for both conditions. Exercise training is a key component of pulmonary rehabilitation (PR) which is now a standard of care for patients with COPD and is symptom based. Although it may be assumed that patients with CHF could be incorporated into cardiac rehabilitation, this is predominantly a secondary prevention programme for patients who are largely asymptomatic. It has been shown that patients with CHF can be successfully trained together with patients with COPD by the same therapists within PR. There are comparable outcome measures that can be used for both COPD and CHF. Many patients with CHF still do not have access to an exercise rehabilitation programme and incorporating them into the PR model of care could be one solution. This article reviews the (1) similar symptoms, mechanisms and consequences between COPD and CHF, (2) rationale and evidence for exercise training in CHF, (3) model of PR, (4) safety of exercise training in CHF, (5) evidence for combined exercise rehabilitation for CHF and COPD, (6) adaptations necessary to include patients with CHF into PR, (7) the chronic care model and (8) summary.

Dual role of Toll-like receptors in asthma and chronic obstructive pulmonary disease

During the last decade, significant research has been focused on Toll-like receptors (TLRs) in the pathogenesis of airway diseases. TLRs are pattern recognition receptors that play pivotal roles in the detection of and response to pathogens. Because of the involvement of TLRs in innate and adaptive immunity, these receptors are currently being exploited as possible targets for drug development. Asthma and chronic obstructive pulmonary disease (COPD) are chronic inflammatory airway diseases in which innate and adaptive immunity play an important role. To date, asthma is the most common chronic disease in children aged 5 years and older. COPD is prevalent amongst the elderly and is currently the fifth-leading cause of death worldwide with still-growing prevalence. Both of these inflammatory diseases result in shortness of breath, which is treated, often ineffectively, with bronchodilators and glucocorticosteroids. Symptomatic treatment approaches are similar for both diseases; however, the underlying immunological mechanisms differ greatly. There is a clear need for improved treatment specific for asthma and for COPD. This review provides an update on the role of TLRs in asthma and in COPD and discusses the merits and difficulties of targeting these proteins as novel treatment strategies for airway diseases. TLR agonist, TLR adjuvant, and TLR antagonist therapies could all be argued to be effective in airway disease management. Because of a possible dual role of TLRs in airway diseases with shared symptoms and risk factors but different immunological mechanisms, caution should be taken while designing pulmonary TLR-based therapies.

The excessive use of inhaled corticosteroids in chronic obstructive pulmonary disease

Despite the fact that the recommendations of the main clinical guidelines have restricted the indications for inhaled corticosteroids in chronic obstructive pulmonary disease (COPD), currently more than 80% of patients are receiving this treatment in Spain, mostly with high doses. A detailed review of the literature does not justify the use of these high doses, a position that agrees with the recommendations of the FDA. A re-evaluation of their safety, the consistency of the data on their efficacy showing similar results with moderate doses and a better patient selection require the use of this treatment in COPD patients to be reconsidered.

Fatigue in bronchiectasis

BACKGROUND

Fatigue is a complex, disabling symptom in non-CF bronchiectasis (nCF-Br). Fatigue can be formally measured using the validated fatigue impact scale (FIS). The relationship between fatigue and clinically important factors such as airflow obstruction, breathlessness or Pseudomonas aeruginosa infection in nCF-Br is unclear.

AIM

To measure the correlation between FIS scores and markers of disease severity in nCF-Br.

DESIGN

A prospective cohort study.

METHODS

Patients attending a specialist service were studied. Lung function (FEV(1)% predicted), Medical Research Council dyspnoea score (MRCD), sputum culture results and FIS were recorded. Patients were categorized according to sputum culture into three subgroups: Pseudomonas 'colonization', 'isolation' and neither.

RESULTS

One hundred and seventeen consecutive patients were included. Average FEV(1)% predicted was 64% (SD ±28%). Twelve (10%) patients had Pseudomonas aeruginosa isolation; 47 (40%) patients had P. aeruginosa colonization. Fatigue levels were similar in patients with and without colonization (median 38 versus 32, P = 0.155). Significant fatigue (FIS > 40) was similar in all three Pseudomonas subgroups (P = 0.31, chi-square). Fatigue correlated with MRCD score (r = 0.57, P < 0.001) and FEV(1)% predicted (r = -0.30, P = 0.001). FEV(1)% predicted was lower in patients who had ever isolated or been colonized with P. aeruginosa (P ≤ 0.001).

CONCLUSION

There are significant correlations between FIS score and MRCD score and FEV(1)% predicted in bronchiectasis. Pseudomonas aeruginosa infection appears to be associated with poorer lung function, and higher MRCD scores, yet there is no significant association between P. aeruginosa status and fatigue.

Common geriatric conditions and disabilities in older persons with chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent chronic diseases among older persons worldwide and the rapid increase in commonly associated COPD-disabilities requires urgent awareness among healthcare professionals. The presence of pulmonary and extrapulmonary comorbidities is highly prevalent among COPD patients and complicates treatment management, especially in advanced age. Some of the most common geriatric conditions in COPD patients lead to respiratory function decline, physical function impairment with limited physical performance, cognitive decline, and depression. Unfortunately, the activation of each component may lead to the progression of the other, which, if not corrected, will lead to critical clinical outcomes such as disability (as seen by the worsening of each condition) and death.

RECENT FINDINGS

Studies in older persons with COPD have shown that disability is mainly due to the severity of comorbidities that have been shown to significantly impact treatment options and the prognosis for such individuals. In addition to spirometric functional parameters, exercise performance and efficacy of specific therapeutic interventions may be useful indicators for overall health status and outcomes. The scientific literature underlines the necessity to use additional parameters other than spirometry for COPD patient monitoring.

SUMMARY

As disability is a growing phenomenon in COPD and substantially impacts patient perception of the disease, we will highlight the recent literature regarding the importance of common geriatric conditions leading to disability in older COPD patients. In particular, we will discuss the impact of the following conditions in older patients with COPD: respiratory function decline, physical function impairment, and mood disorders. Clinical use for measuring such parameters in COPD elderly will aid in identifying those at risk for severe clinical decline.

Comorbidities of chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Defining the nature of the association between chronic obstructive pulmonary disease (COPD) and other chronic conditions is of primary importance to improve the health status of COPD patients through the optimal care of comorbidities. We aimed at providing a reasoned guide to understand, recognize and treat comorbidity of COPD with the perspective of shifting from comorbidity to multimorbidity.

RECENT FINDINGS

Select comorbidities, such as atherosclerotic disease, depression, chronic kidney disease, cognitive impairment, obstructive sleep apnea syndrome, lung cancer, osteoporosis, diabetes, heart failure, sarcopenia, aortic aneurysm, arrhythmias and pulmonary embolism are highly prevalent among older COPD patients. Several concerns may affect the management of older COPD patients with comorbidity (e.g. the use of β-blockers in patients with COPD and cardiovascular diseases or concerns about the cardiovascular safety of inhaled COPD drugs).

SUMMARY

Evidence suggests that systemic inflammation may be the link between COPD and comorbidities, but this issue is still debated. Whatever the mechanism underlying comorbidities in COPD may be, it has an important clinical, prognostic and therapeutic impact. Nevertheless, clinical practice guidelines do not take into account comorbidities in their recommendations. Additionally, clinical trials investigating COPD treatment in the context of multimorbidity and considering geriatric outcomes are also distinctly lacking.

Progression of osteoporosis in patients with COPD: a 3-year follow up study

Currently, our knowledge on the progression of osteoporosis and its determinants is limited in patients with chronic obstructive pulmonary disease (COPD). Bone mineral density generally remains stable in patients with COPD over a period of 3 years. Nevertheless, the progression of vertebral fractures was not assessed, while an increase of vertebral fractures over time may be reasonable. Aims of the current study were to determine the percentage of newly diagnosed osteoporotic patients after a follow up of 3 years and to identify baseline risk factors for the progression of osteoporosis in COPD. Clinically stable COPD outpatients were included. Lung function parameters, body composition measures, six minute walk distance, DXA-scan and X-spine were assessed at baseline and repeated after 3 years. Prevalence of osteoporosis in COPD patients increased from 47% to 61% in 3 years mostly due to an increase of vertebral fractures. Lower baseline T-score at the trochanter independently increased the risk for the development of osteoporosis. Additionally, baseline vitamin D deficiency increased this risk 7.5-fold. In conclusion, the prevalence of osteoporosis increased over a 3-year period in patients with COPD. Baseline risk factors for the development of osteoporosis are osteopenia at the trochanter and vitamin D deficiency.

Airflow obstruction, lung function, and risk of incident heart failure: the Atherosclerosis Risk in Communities (ARIC) study

AIMS

We examined the relationship between forced expiratory volume in 1 s (FEV(1)), airflow obstruction, and incident heart failure (HF) in black and white, middle-aged men and women in four US communities.

METHODS AND RESULTS

Lung volumes by standardized spirometry and information on covariates were collected on 15 792 Atherosclerosis Risk in Communities (ARIC) cohort participants in 1987-89. Incident HF was ascertained from hospital records and death certificates up to 2005 in 13 660 eligible participants. Over an average follow-up of 14.9 years, 1369 (10%) participants developed new-onset HF. The age- and height-adjusted hazard ratios (HRs) for HF increased monotonically over descending quartiles of FEV(1) for both genders, race groups, and smoking status. After multivariable adjustment for traditional cardiovascular risk factors and height, the HRs [95% confidence intervals (CIs)] of HF comparing the lowest with the highest quartile of FEV(1) were 3.91 (2.40-6.35) for white women, 3.03 (2.12-4.33) for white men, 2.11 (1.33-3.34) for black women, and 2.23 (1.37-3.59) for black men. The association weakened but remained statistically significant after additional adjustment for systemic markers of inflammation. The multivariable adjusted incidence of HF was higher in those with FEV(1)/forced vital capacity <70% vs. ≥70%: HR 1.44 (95% CI 1.20-1.74) among men and 1.40 (1.13-1.72) among women. A consistent and positive association with HF was seen for self-reported diagnosis of emphysema and chronic obstructive pulmonary disease, but not for asthma.

CONCLUSIONS

In this large population-based cohort with long-term follow-up, low FEV(1) and an obstructive respiratory disease were strongly and independently associated with the risk of incident HF.

How the genetics of lung cancer may overlap with COPD

Over the last 30years, epidemiological studies have shown that COPD is the single most important risk factor for lung cancer after smoking exposure. Recent genetic studies using genome-wide approaches suggest that the genetic risk factors predisposing smokers to COPD and lung cancer may overlap. The genes identified by these studies suggest that this overlapping genetic susceptibility may be mediated through receptors expressed on the bronchial epithelium that implicate molecular pathways underlying both COPD and lung cancer. Furthermore, it appears that aberrant inflammatory and/or immune-modulatory pathways leading to excess matrix metalloproteinases, growth factors and airway remodelling in COPD may also be promoting malignant transformation of the bronchial epithelium. The process linking inflammation, remodelling and cancer formation is called epithelial-mesenchymal transition. There are several clinical implications arising from the COPD-lung cancer overlap. First, if COPD is a precursor disease to lung cancer then efforts to prevent COPD, might be even more important. Second, if drugs targeting the overlapping molecular pathways can be identified, chemoprevention that reduce the propensity to COPD and lung cancer is an attractive option. Finally, if low-dose computerized tomography can identify treatable lung cancer, gene-based tests of susceptibility might help identify those smokers who should undergo radiological screening.

Neurological and endocrinological disorders: orphans in chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) are often characterised by a range of characteristic co-morbidities that interfere with their pulmonary disease. In addition to a mere association with co-morbidities, a complex pathophysiological interaction and mutual augmentation occurs between COPD and its co-morbidities that may result in disease progression and increased morbidity and mortality. An interdisciplinary approach is required both for diagnosis and treatment to target co-morbidities early in the course of the disease. This review summarizes the current knowledge of the interaction with cerebrovascular disease and endocrinological co-morbidities in COPD patients. There is growing evidence that COPD is an independent risk factor for ischemic stroke, increasing the risk about twofold. Stroke risk in COPD patients increases with the severity of the disease as measured by the degree of airflow limitation. The presence of cardiovascular risk factors is of particular importance for stroke prevention in COPD patients. Endocrinological co-morbidities are also important and many are associated with increased cardiovascular risk. Impaired glucose metabolism ranges from insulin resistance to overt diabetes mellitus, which is a frequent finding and is associated with worse outcome.

Muscle and blood redox status after exercise training in severe COPD patients

Beneficial effects of exercise training in patients with chronic obstructive pulmonary disease (COPD) are acknowledged. However, high-intensity exercise may enhance muscle oxidative stress in severe COPD patients. We hypothesized that high-intensity exercise training of long duration does not deteriorate muscle redox status. In the vastus lateralis and blood of 18 severe COPD patients and 12 controls, before and after an 8-week training program, protein oxidation and nitration, antioxidant systems, and inflammatory cytokines were examined. At baseline, COPD patients showed greater muscle oxidative stress and superoxide dismutase activity and circulating inflammatory cytokines than controls. Among COPD patients, muscle and blood protein carbonylation levels were correlated. Both groups showed training-induced increase in VO(2) peak and decreased blood lactate levels. After training, among the COPD patients, blood protein nitration levels were significantly reduced and muscle protein oxidation and nitration levels did not cause impairment. Muscle and blood levels of inflammatory cytokines were not modified by training in either patients or controls. We conclude that in severe COPD patients, high-intensity exercise training of long duration improves exercise capacity while preventing the enhancement of systemic and muscle oxidative stress. In addition, in these patients, resting protein oxidation levels correlate between skeletal muscle and blood compartments.

Pulmonary-intestinal cross-talk in mucosal inflammatory disease

Chronic obstructive pulmonary disease (COPD) and inflammatory bowel diseases (IBDs) are chronic inflammatory diseases of mucosal tissues that affect the respiratory and gastrointestinal tracts, respectively. They share many similarities in epidemiological and clinical characteristics, as well as in inflammatory pathologies. Importantly, both conditions are accompanied by systemic comorbidities that are largely overlooked in both basic and clinical research. Therefore, consideration of these complications may maximize the efficacy of prevention and treatment approaches. Here, we examine both the intestinal involvement in COPD and the pulmonary manifestations of IBD. We also review the evidence for inflammatory organ cross-talk that may drive these associations, and discuss the current frontiers of research into these issues.

Disturbance of the OPG/RANK/RANKL pathway and systemic inflammation in COPD patients with emphysema and osteoporosis

BACKGROUND

Osteoporosis is one of the systemic features of COPD. A correlation between the emphysema phenotype of COPD and reduced bone mineral density (BMD) is suggested by some studies, however, the mechanisms underlying this relationship are unclear. Experimental studies indicate that IL-1β, IL-6 and TNF-α may play important roles in the etiology of both osteoporosis and emphysema. The OPG/RANK/RANKL system is an important regulator of bone metabolism, and participates in the development of post-menopausal osteoporosis. Whether the OPG/RANK/RANKL pathway is involved in the pathogenesis of osteoporosis in COPD has not been studied.

METHODS

Eighty male patients (current or former smokers) completed a chest CT scan, pulmonary function test, dual x-ray absorptiometry measurements and questionnaires. Among these subjects, thirty patients with normal BMD and thirty patients with low BMD were selected randomly for measurement of IL-1β, IL-6, TNF-α (flow cytometry) and OPG/RANK/RANKL (ELISA). Twenty age-matched healthy volunteers were recruited as controls.

RESULTS

Among these eighty patients, thirty-six had normal BMD and forty-four had low BMD. Age, BMI and CAT score showed significant differences between these two COPD groups (p < 0.05). The low-attenuation area (LAA%) in the lungs of COPD patients was negatively correlated with lumbar vertebral BMD (r = 0.741; p < 0.0001). Forward logistic regression analysis showed that only LAA% (p = 0.005) and BMI (p = 0.009) were selected as explanatory variables. The level of IL-1β was significantly higher in the COPD patients as compared to the normal controls (p < 0.05), but the difference between the two COPD groups did not reach significance. The levels of IL-6 and TNF-α among the three groups were significantly different (p < 0.05). The level of RANKL and the RANKL/OPG ratio were significantly higher in COPD patients with low BMD compared to those with normal BMD and the normal controls (p < 0.05), and correlated negatively with lumbar vertebral BMD, but positively with LAA%.

CONCLUSIONS

Radiographic emphysema is correlated with low BMD in current and former smokers with COPD. IL-1β, IL-6, TNF-α, and the osteoporosis-related protein system OPG/RANK/RANKL may have some synergetic effects on emphysema and bone loss in COPD.

Low-grade adipose tissue inflammation in patients with mild-to-moderate chronic obstructive pulmonary disease

BACKGROUND

Low-grade systemic inflammation is common in chronic obstructive pulmonary disease (COPD), but its source remains unclear. Adipose tissue is a potent producer of inflammatory mediators and may contribute to systemic inflammation in COPD, possibly via hypoxia.

OBJECTIVE

We studied the influence of COPD and exercise-induced oxygen desaturation on adipose tissue inflammation (ATI) and its contribution to systemic inflammation.

DESIGN

Subcutaneous adipose tissue biopsies were investigated in 28 clinically stable COPD patients [forced expiratory volume in 1 s: 58 ± 16% predicted; BMI (in kg/m(2)): 24.9 ± 2.9] and 15 age-, sex-, and body composition-matched healthy control subjects. Fat mass was measured with dual-energy X-ray absorptiometry. Patients were prestratified by oxygen desaturation assessed by incremental cycle ergometry. The adipocyte size and adipose tissue expression of 19 inflammatory and hypoxia-related genes were measured, and adipose tissue macrophages (ATMs) were histologically quantified. Systemic inflammatory markers included C-reactive protein (CRP) and a panel of 20 adipokines.

RESULTS

COPD patients had comparable fat mass but higher CRP and HOMA-IR than did control subjects. COPD patients and control subjects had comparable adipose tissue gene expression, adipocyte size, ATM infiltration, and systemic adipokine concentrations. Desaturating COPD patients had no different ATI status than did nondesaturating COPD patients. COPD patients with high CRP had significantly greater ATM infiltration than did patients with low CRP, which was independent of BMI and fat mass.

CONCLUSIONS

In COPD patients, mild-to-moderate COPD, per se, does not enhance ATI or its contribution to systemic inflammation compared with in well-matched healthy control subjects. However, to our knowledge, our study provides a first indication for a possible role of ATMs in the systemic inflammatory response in COPD that requires additional investigation. This trial was registered at www.trialregister.nl as NTR1402.

The prevalence of undiagnosed renal failure in a cohort of COPD patients in western Norway

Patients with COPD are at risk for other comorbid diseases, like heart failure, coronary heart disease, and depression. However, little is known about COPD phenotypes and prevalence of sub-clinical renal failure. 433 COPD patients and 233 subjects without COPD, from Western Norway, age 40-75, GOLD stage II-IV, were examined in 2006/07 upon entry to the Bergen COPD Cohort Study. Plasma creatinine was measured in 422 of the COPD patients. The Glomerular Flow Rate (GFR) was determined with the Cockcroft Gault formula, and having a GFR < 60 was defined as renal failure. Examined explanatory factors were sex, age, smoking habits, GOLD stage, hypoxemia, exacerbation history, cachexia, use of daily inhaled steroids, Charlson comorbidity score, use of ACE inhibitors and/or ARBs, and the inflammatory plasma markers C-reactive protein (CRP), soluble tumor necrosis factor receptor 1 (sTNF-R1) and neutrophil gelatinase associated lipocalin (NGAL). Associations between explanatory variables and renal failure were examined by a logistic regression analysis. The prevalence of having GFR < 60 was 9.6% in female COPD patients and 5.1% in male COPD patients (p = 0.08). In multivariable analysis, female sex, higher age, cachexia, and the inflammatory markers sTNF-R1 and NGAL were all independently associated with a higher risk for renal failure, whereas use of inhaled steroids, Charlson score, GOLD stage, respiratory failure, and exacerbation frequency were not. Undiagnosed renal failure is a concern particularly in elderly COPD patients and COPD patients with cachexia.

Initial risk assessment for pulmonary hypertension in patients with COPD

BACKGROUND

Pulmonary hypertension (PH) is a comorbidity associated with increased mortality in chronic obstructive pulmonary disease (COPD) patients. It is not known which clinical markers are predictive of PH in COPD. The goal of this study was to develop a clinical tool to identify patients who should be sent for initial screening with echocardiography.

METHODS

Of 127 patients screened, 94 primary-care patients with COPD were enrolled. All underwent full pulmonary function testing, 6-minute walk distance (6MWD), exercise oximetry, Saint George's Respiratory Questionnaire, and transthoracic echocardiography. Eighty-six patients had measurable pulmonary artery pressures (PAP) on echocardiography. Elevated PAP was defined as a systolic PAP > 35 mmHg.

RESULTS

Pre- and post-bronchodilator FEV(1) (P = 0.04 and P = 0.03, respectively), exercise oxyhemoglobin desaturation (P = 0.003), and 6MWD (P = 0.004) were associated with elevated PAP on univariate analysis. Diffusion capacity was lower but did not reach statistical significance (P = 0.07). In multivariate analysis, statistically significant independent variables were >3% decrease in exercise oxyhemoglobin saturation and decline in prebronchodilator FEV(1) (P = 0.01 and P = 0.04, respectively). A composite prediction model was developed that assigned one point for each of the following: age > 55 years, oxyhemoglobin desaturation > 3%, prebronchodilator FEV(1) < 50% predicted, and 6MWD < 1175 ft. Prevalence rates of elevated PAP were 32% for a score of 0-1 (low risk), 68% for a score of 2 (moderate risk), and 78% for a score of 3-4 (high risk). The composite score exhibited a strong trend with elevated PAP prevalence (Cochrane-Armitage trend statistic P = 0.001).

CONCLUSION

A simple prediction tool using routine office-based parameters can be used to identify COPD patients at high risk for elevated PAP and initiate the first step in screening for PH with echocardiography. It is important that right heart catheterization be performed to confirm the diagnosis and guide treatment decisions.

Cyclooxygenase-2 -765G>C polymorphism is associated with C-reactive protein levels in resistant smokers but not in chronic obstructive pulmonary disease patients

We sought to investigate whether the serum concentrations of several inflammatory biomarkers are related to the cyclooxygenase-2 (COX2) -765G>C polymorphism in chronic obstructive pulmonary disease (COPD) and a control group of non-COPD smokers. Serum inflammatory markers (CRP, SAA, CXCL8, and sICAM-1) were measured by ELISA in 144 patients with COPD and in 55 control subjects. Genomic DNA was extracted from peripheral blood leukocytes, and the COX2 -765G>C (rs20417) polymorphism was genotyped. After adjustment for age and active smoking, CRP and SAA concentrations were associated with the COX2 polymorphism in controls (p=0.041 and 0.014, respectively) but not in COPD patients. The CXCL8 and sICAM-1 concentrations were not associated with the COX2 polymorphism for either cases or controls. The results of the present study indicate that there is a relationship between the COX2 -765G>C polymorphism and the concentrations of CRP and SAA in non-COPD smokers and that this relationship does not exist in COPD patients.

Use of cluster analysis to describe desaturator phenotypes in COPD: correlations between pulmonary function tests and nocturnal oxygen desaturation

BACKGROUND

Significant heterogeneity of clinical presentation and disease progression exists within chronic obstructive pulmonary disease (COPD). Although forced expiratory volume in 1 second (FEV(1)) inadequately describes this heterogeneity, a clear alternative has not emerged. This article discusses and refines the concept of phenotyping desaturators in COPD and shows a possible pattern which could be used as a framework for future research.

RECENT FINDINGS

COPD is a complex condition with pulmonary and extrapulmonary manifestations. We suggest that COPD phenotypes should be associated with clinically meaningful outcomes. The innovation of COPD phenotyping is defined as COPD desaturators. Sleep-related hypoxemia and hypercapnia are well recognized in COPD and the development of systemic inflammation during sleep. These sleep-related changes predispose to nocturnal cardiac arrhythmias, pulmonary hypertension, and possibly death, particularly during acute exacerbations.

CONCLUSION

A more focused definition makes possible a classification of patients into two distinct subgroups for both clinical and research purposes. Establishing a common language for future research will facilitate our understanding and management of such diseases. Even if different treatment strategies have different outcomes for these groups, we will have confirmation, or otherwise, of the clinical value of cluster analysis. This knowledge could lead to pharmacological treatment and other interventions directed to specific phenotypic groups.

[Treating COPD in chronic patients in a primary-care setting]

The aging of the populations in Western countries entails an increase in chronic diseases, which becomes evident with the triad of age, comorbidities and polymedication. chronic obstructive pulmonary disease represents one of the most important causes of morbidity and mortality, with a prevalence in Spain of 10.2% in the population aged 40 to 80. In recent years, it has come to be defined not only as an obstructive pulmonary disease, but also as a systemic disease. Some aspects stand out in its management: smoking, the main risk factor, even though avoidable, is an important health problem; very important levels of underdiagnosis and little diagnostic accuracy, with inadequate use of spirometry; chronic patient profile; exacerbations that affect survival and cause repeated hospitalizations; mobilization of numerous health-care resources; need to propose integral care (health-care education, rehabilitation, promotion of self-care and patient involvement in decision-making).

Roflumilast, a Novel Phosphodiesterase 4 Inhibitor, for COPD Patients with a History of Exacerbations

Acute exacerbations of COPD (AECOPD) are major clinical events. They are associated with a more rapid decline in lung function, poorer quality of life scores, and an increased risk of dying. Exacerbations that require hospitalization have particular significance. Approximately 40% of the AECOPD patients who require hospitalization will die in the subsequent year. Since many AECOPD require hospitalization, they account for most of the expense of caring for COPD patients. Treatment with long-acting bronchodilators and combination inhaled corticosteroid/long-acting bronchodilator inhalers reduces but does not eliminate AECOPD. Roflumilast, a selective phosphodiesterase 4 (PDE4) inhibitor, is an anti-inflammatory medication that improves lung function in patients with COPD. In patients with more severe airway obstruction, clinical features of chronic bronchitis, and a history of AECOPD, roflumilast reduces the frequency of AECOPD when given in combination with short-acting bronchodilators, long-acting bronchodilators, or inhaled corticosteroids. It is generally well tolerated but the most common adverse effects include diarrhea, nausea, weight loss, and headaches. In clinical trials, patients treated with roflumilast experienced weight loss that averaged just over 2 kg but was primarily due to the loss of fat tissue. Weight loss was least in underweight patients and obese patients experienced the greatest weight loss. An unexpected benefit of treatment with roflumilast was that fasting blood glucose and hemoglobin A1c levels improved in patients with comorbid type 2 diabetes mellitus. Roflumilast, the first selective PDE4 inhibitor to be marketed, is a promising drug for the management of COPD patients with more severe disease.

Epithelial nuclear factor-κB signaling promotes lung carcinogenesis via recruitment of regulatory T lymphocytes

The mechanisms by which chronic inflammatory lung diseases, particularly chronic obstructive pulmonary disease (COPD), confer enhanced risk for lung cancer are not well defined. To investigate whether nuclear factor (NF)-κB, a key mediator of immune and inflammatory responses, provides an interface between persistent lung inflammation and carcinogenesis, we utilized tetracycline-inducible transgenic mice expressing, constitutively active IκB kinase β in airway epithelium (IKTA mice). Intraperitoneal injection of ethyl carbamate (urethane) or 3-methylcholanthrene (MCA) and butylated hydroxytoluene (BHT) was used to induce lung tumorigenesis. Doxycycline-treated IKTA mice developed chronic airway inflammation and markedly increased numbers of lung tumors in response to urethane, even when transgene expression (and therefore epithelial NF-κB activation) was begun after exposure to carcinogen. Studies using a separate tumor initiator/promoter model (MCA+BHT) indicated that NF-κB functions as an independent tumor promoter. Enhanced tumor formation in IKTA mice was preceded by increased proliferation and reduced apoptosis of alveolar epithelium, resulting in increased formation of premalignant lesions. Investigation of inflammatory cells in lungs of IKTA mice revealed a substantial increase in macrophages and lymphocytes, including functional CD4+/CD25+/FoxP3+ regulatory T lymphocytes (Tregs). Importantly, Treg depletion using repetitive injections of anti-CD25 antibodies limited excessive tumor formation in IKTA mice. At 6 weeks following urethane injection, antibody-mediated Treg depletion in IKTA mice reduced the number of premalignant lesions in the lungs in association with an increase in CD8 lymphocytes. Thus, persistent NF-κB signaling in airway epithelium facilitates carcinogenesis by sculpting the immune/inflammatory environment in the lungs.

Involvement of creatine kinase B in cigarette smoke-induced bronchial epithelial cell senescence

Cigarette smoke induces damage to proteins and organelles by oxidative stress, resulting in accelerated epithelial cell senescence in the lung, which is implicated in chronic obstructive pulmonary disease (COPD) pathogenesis. Although the detailed molecular mechanisms are not fully understood, cellular energy status is one of the most crucial determinants for cell senescence. Creatine kinase (CK) is a constitutive enzyme, playing regulatory roles in energy homeostasis of cells. Among two isozymes, brain-type CK (CKB) is the predominant CK in lung tissue. In this study, we investigated the role of CKB in cigarette smoke extract (CSE)-induced cellular senescence in human bronchial epithelial cells (HBECs). Primary HBECs and Beas2B cells were used. Protein carbonylation was evaluated as a marker of oxidative protein damage. Cellular senescence was evaluated by senescence-associated β-galactosidase staining. CKB inhibition was examined by small interfering RNA and cyclocreatine. Secretion of IL-8, a hallmark of senescence-associated secretary phenotype, was measured by ELISA. CKB expression levels were reduced in HBECs from patients with COPD compared with that of HBECs from nonsmokers. CSE induced carbonylation of CKB and subsequently decreased CKB protein levels, which was reversed by a proteasome inhibitor. CKB inhibition alone induced cell senescence, and further enhanced CSE-induced cell senescence and IL-8 secretion. CSE-induced oxidation of CKB is a trigger for proteasomal degradation. Concomitant loss of enzymatic activity regulating energy homeostasis may lead to the acceleration of bronchial epithelial cell senescence, which is implicated in the pathogenesis of COPD.

A unique protein profile of peripheral neutrophils from COPD patients does not reflect cytokine-induced protein profiles of neutrophils in vitro

Background

Inflammation, both local and systemic, is a hallmark of chronic obstructive pulmonary disease (COPD). Inflammatory mediators such as TNFα and GM-CSF are secreted by lung epithelium, alveolar macrophages and other inflammatory cells and are thought to be important contributors in the pathogenesis of COPD. Indeed, neutrophils are activated by these cytokines and these cells are one of the major inflammatory cell types recruited to the pulmonary compartment of COPD patients. Furthermore, these inflammatory mediators are found in the peripheral blood of COPD patients and, therefore, we hypothesized that TNFα/GM-CSF-induced protein profiles can be found in peripheral neutrophils of COPD patients.

Methods

Using fluorescence 2-dimensional difference gel electrophoresis we investigated differentially regulated proteins in peripheral neutrophils from COPD patients and healthy age-matched control subjects. Furthermore, protein profiles from COPD patients were compared with those of neutrophils of healthy age-matched controls that were stimulated with TNFα and/or GM-CSF in vitro. Protein gels were compared using DeCyder 7.0 software.

Results

We identified 7 significantly regulated protein spots between peripheral neutrophils from COPD patients and age-matched healthy control subjects. Stimulation of peripheral neutrophils with TNFα, GM-CSF or TNFα + GM-CSF in vitro resulted in 13, 20 and 22 regulated protein spots, respectively. However, these cytokine-induced protein differences did not correspond with the protein differences found in neutrophils from COPD patients.

Conclusion

These results show that neutrophils from COPD patients have a unique protein profile compared to neutrophils from healthy age-matched controls. Furthermore, the neutrophil profiles of COPD patients do not reflect putative dominant signals induced by TNFα, GM-CSF or their combination. Our results indicate that systemic neutrophil responses in COPD patients are caused by a unique but subtle interplay between multiple inflammatory signals.

Myocardial infarction and other co-morbidities in patients with chronic obstructive pulmonary disease: a Danish nationwide study of 7.4 million individuals

AIMS

Myocardial infarction is nominally the most important co-morbidity in patients with chronic obstructive pulmonary disease, and the one with the greatest potential for treatment and prevention to improve the overall prognosis of chronic obstructive pulmonary disease patients. We assessed the extent of myocardial infarction and other co-morbidities in individuals with chronic obstructive pulmonary disease in the general population.

METHODS AND RESULTS

We used individual participant data for the entire Danish population from 1980 through 2006, comprising 140 million person-years of follow-up. We used information from four national Danish registries with 100% follow-up and detected ever-diagnosed chronic obstructive pulmonary disease (n = 313,958) and incident cases of a first myocardial infarction (n = 422,344), lung cancer (n = 116,629), hip fracture (n = 53,756), depression (n = 93 038), and diabetes mellitus (n = 292 228). Multivariate adjusted hazard ratios for life-time association with ever-diagnosed chronic obstructive pulmonary disease were 1.26 (95% CI 1.25-1.27) for myocardial infarction, 2.05 (2.03-2.08) for lung cancer, 2.12 (2.07-2.17) for hip fracture, 1.74 (1.70-1.77) for depression, and 1.21 (1.20-1.23) for diabetes mellitus, compared with controls; these risk estimates were highest in women and the youngest age groups. Before the first hospitalization with chronic obstructive pulmonary disease, multivariate adjusted odds ratios were 1.47 (1.44-1.49) for myocardial infarction, 3.68 (3.52-3.84) for lung cancer, 1.16 (1.13-1.18) for hip fracture, 1.88 (1.80-1.96) for depression, and 1.16 (1.13-1.18) for diabetes mellitus, compared with matched controls. Corresponding values after a chronic obstructive pulmonary disease hospitalization were 0.74 (0.73-0.76), 1.48 (1.45-1.51), 1.23 (1.20-1.27), 1.21 (1.18-1.24), and 0.83 (0.81-0.85), respectively.

CONCLUSION

Chronic obstructive pulmonary disease was associated with higher rates of myocardial infarction, lung cancer, diabetes, hip fracture, and depression, but the strength of these associations was modified after a first admission for chronic obstructive pulmonary disease. These associations may be related to common genetic and/or lifestyle/environmental risk factors, and therefore these factors are likely to have an adverse health impact rather than chronic obstructive pulmonary disease per se.

Preresection serum C-reactive protein measurement and survival among patients with resectable non-small cell lung cancer

OBJECTIVE

This study aimed to determine whether preresection serum CRP level independently predicts survival among patients with resectable non-small cell lung cancer.

METHODS

Clinical, pathologic, and laboratory data from 300 patients operated on for non-small cell lung cancer in a single institution were studied in univariate and multivariate survival analyses. Validation was sought in another cohort of 68 similar patients from another institution.

RESULTS

In the main cohort, preoperative CRP value was 3 mg/L or lower in 136 patients (45.3%), between 4 and 20 mg/L in 89 (29.7%), and greater than 20 in 64 (21.3%). CRP level was significantly associated with chronic bronchitis, hypoalbuminemia, pathologic stage, and peritumoral vascular emboli. Overall, 5-year survivals of patients with preoperative CRP 3 mg/L or lower, between 4 and 20 mg/L, and greater than 20 mg/L were 55.6%, 45.6%, and 40.0%, respectively (P = .0571). In multivariate analysis, CRP level greater than 20 was significantly associated with survival, but with significant interaction between CRP level and disease stage (P = .02). Patients in stage I or II disease with CRP levels greater than 20 had worse survival than did patients with undetectable CRP (adjusted hazard ratio, 1.874; 95% confidence interval, 1.039-3.381); the difference was not significant in stages III and IV. In the validation series, CRP level greater than 20 mg/L also predicted worse survival (P = .018).

CONCLUSIONS

Preoperative CRP level greater than 20 mg/L is significantly associated with worse survival than undetectable CRP in patients with stage I or II non-small cell lung cancer.

The association between systemic inflammatory cellular levels and lung function: a population-based study

BACKGROUND

Lower lung function is associated with an elevated systemic white cell count in men. However, these observations have not been demonstrated in a representative population that includes females and may be susceptible to confounding by recent airway infections or recent cigarette smoking. We tested the hypothesis that lung function is inversely associated with systemic white cell count in a population-based study.

METHODS

The study population consisted adults aged 17-90+ years who participated in the Third National Health and Nutrition Examination Survey who did not report a recent cough, cold or acute illness in a non-smoking and smoking population.

RESULTS

In non-smoking adults with the highest quintile of the total white cell count had a FEV(1) 125.3 ml lower than those in the lowest quintile (95% confidence interval CI: -163.1 to -87.5). Adults with the highest quintile of the total white cell count had a FVC 151.1 ml lower than those in the lowest quintile (95% confidence interval CI: -195.0 to -107.2). Similar associations were observed for granulocytes, mononuclear cells and lymphocytes. In current smokers, similar smaller associations observed for total white cell count, granulocytes and mononuclear cells.

CONCLUSIONS

Systemic cellular inflammation levels are inversely associated with lung function in a population of both non-smokers and smokers without acute illnesses. This may contribute to the increased mortality observed in individuals with a higher baseline white cell count.