Why are patients with chronic obstructive pulmonary disease at increased risk of cardiovascular diseases? The potential role of systemic inflammation in chronic obstructive pulmonary disease

The challenges of chronic obstructive pulmonary diseases (COPD)--a perspective

Chronic Obstructive Pulmonary Disease (COPD) is an inflammatory disease, primarily caused by cigarette smoke, which will soon become the third leading cause of death globally. Despite the importance of the problem, our real understanding of the biological underpinnings of COPD remains incomplete. Consequently, our first-line therapies, while helpful, are not yet as effective as they need to be. In this review, we will focus on these challenges and more, including the role of impaired tissue repair and adaptive immunity in disease pathogenesis, determining who may be at risk, describing COPD phenotypes and potential biomarkers. New ideas for chronic disease management and prevention of exacerbations will also be discussed. While much remains to be accomplished, meeting these challenges will bring rewards because what we learn will have implications for the understanding and treatment of chronic inflammatory diseases beyond COPD.

C-reactive Protein As a Predictor of Prognosis in Chronic Obstructive Pulmonary Disease

RATIONALE

Patients with chronic obstructive pulmonary disease (COPD) have an ongoing systemic inflammation, which can be assessed by measuring serum C-reactive protein (CRP).

OBJECTIVE

To determine whether increased serum CRP in individuals with airway obstruction predicts future hospitalization and death from COPD.

METHODS

We performed a cohort study with a median of 8-yr follow-up of 1,302 individuals with airway obstruction selected from the ongoing Copenhagen City Heart Study.

MEASUREMENTS AND MAIN RESULTS

We measured serum CRP at baseline, and recorded COPD admissions and deaths as outcomes. During follow-up, 185 (14%) individuals were hospitalized due to COPD and 83 (6%) died of COPD. Incidences of COPD hospitalization and COPD death were increased in individuals with baseline CRP > 3 mg/L versus < or = 3 mg/L (log rank: p < 0.001). After adjusting for sex, age, FEV(1)% predicted, tobacco consumption, and ischemic heart disease, the hazard ratios for hospitalization and death due to COPD were increased at 1.4 (95% confidence interval, 1.0-2.0) and 2.2 (1.2-3.9) in individuals with baseline CRP > 3 mg/L versus < or = 3 mg/L. After close matching for FEV(1)% predicted and adjusting for potential confounders, baseline CRP was, on average, increased by 1.2 mg/L (analysis of variance: p = 0.002) and 4.1 mg/L (p = 0.001) in those who were subsequently hospitalized or died of COPD, respectively. The absolute 10-yr risks for COPD hospitalization and death in individuals with CRP above 3 mg/L were 54 and 57%, respectively, among those older than 70 yr with a tobacco consumption above 15 g/d and an FEV(1)% predicted of less than 50.

CONCLUSIONS

CRP is a strong and independent predictor of future COPD outcomes in individuals with airway obstruction.

Childhood maltreatment predicts adult inflammation in a life-course study

Stress in early life has been associated with insufficient glucocorticoid signaling in adulthood, possibly affecting inflammation processes. Childhood maltreatment has been linked to increased risk of adult disease with potential inflammatory origin. However, the impact of early life stress on adult inflammation is not known in humans. We tested the life-course association between childhood maltreatment and adult inflammation in a birth cohort followed to age 32 years as part of the Dunedin Multidisciplinary Health and Development Study. Regression models were used to estimate the effect of maltreatment on inflammation, adjusting for co-occurring risk factors and potential mediating variables. Maltreated children showed a significant and graded increase in the risk for clinically relevant C-reactive protein levels 20 years later, in adulthood [risk ratio (RR)=1.80, 95% confidence interval (CI)=1.26-2.58]. The effect of childhood maltreatment on adult inflammation was independent of the influence of co-occurring early life risks (RR=1.58, 95% CI=1.08-2.31), stress in adulthood (RR=1.64, 95% CI=1.12-2.39), and adult health and health behavior (RR=1.76, 95% CI=1.23-2.51). More than 10% of cases of low-grade inflammation in the population, as indexed by high C-reactive protein, may be attributable to childhood maltreatment. The association between maltreatment and adult inflammation also generalizes to fibrinogen and white blood cell count. Childhood maltreatment is a previously undescribed, independent, and preventable risk factor for inflammation in adulthood. Inflammation may be an important developmental mediator linking adverse experiences in early life to poor adult health.

Systemic inflammation in COPD: is genetic susceptibility a key factor?

COPD is a multicomponent disease characterized by abnormal inflammatory response of the lungs to noxious particles that is accompanied by systemic effects like weight loss, muscle wasting, reduced functional capacity and impaired health status. A persistent low-grade systemic inflammatory response reflected by enhanced levels of acute phase proteins like C-reactive protein (CRP) and pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, is present in part of the COPD population. The production of inflammatory proteins is partly genetically determined. Several studies have shown that polymorphisms within genes coding for these inflammatory mediators may modulate systemic inflammatory responses. Among all of these genes, the TNF family (TNF-alpha, lymphotoxin (LT)-alph and their receptors TNF-R55 and TNF-R75), interleukin (IL)-6 and CRP gene polymorphisms are the most prominent candidates. However, large carefully designed studies in well-characterized COPD cohorts are required to unravel the exact role of genetic background in the systemic component of this disease.

Systemic inflammation and mortality in chronic obstructive pulmonary diseaseThis paper is one of a selection of papers published in this Special Issue, entitled Young Investigators' Forum

Cardiovascular diseases and cancer (especially lung cancer) are leading causes of morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD). Some have implicated systemic inflammation, which is commonly observed in COPD, as the potential mechanistic bridge between COPD and these disorders. This concept has been supported by animal studies especially in rabbits, which have clearly demonstrated the effect of local lung inflammation on systemic inflammation and on the progression of atherosclerosis and by cross-sectional population-based studies, which have shown a significant relationship between systemic inflammation, as measured by circulating C-reactive protein (CRP) and the risk of cardiovascular diseases in COPD patients. These data have been further extended by a recent study that has elucidated the temporal nature of the relationship between systemic inflammation and the risk of cardiovascular events and cancer in COPD patients. This study showed that baseline CRP levels predicted the incidence of cardiovascular events and cancer-specific mortality over 7 to 8 years of follow-up. CRP levels also predicted all-cause mortality. Collectively, these data indicate that systemic inflammation may play an important role in mediating the extra-pulmonary complications of COPD. Systemic inflammation may contribute substantially to the overall morbidity and mortality of COPD patients.

Increased vascular contractility in isolated vessels from cigarette smoking rats is mediated by basal endothelin release

The effect of chronic cigarette smoking on endothelin modulation of vascular contraction, and CYP enzyme levels was studied in 20 male Sprague-Dawley rats. The animals were divided equally into smoking and non-smoking groups. The smoking group was exposed to 6 research cigarettes per rat per day 5 days a week for 16 weeks. The control group was sham smoked. Functional contractile studies were performed in aortas and carotid arteries to determine the regulation of vascular tone by basal release of endothelin. Liver samples were analyzed for CYP1A1 and CYP1A2 gene expression by RT-PCR. Plasma samples were assessed for endothelin-1 (ET-1) level by enzyme immuno assay (EIA). Treatment of aortas and carotid arteries with bosentan, the dual endothelin receptor antagonist, caused a significant reduction in constrictor responses of smoking rats, indicating, increase greater regulation of tone by endothelin in smoker rats compared to controls. There was a greater expression of the cytochrome P450-liver enzymes (CYP1A1 and CYP1A2) in smoker rats. Body weight gain was also significantly decreased in smoker rats. We conclude that increased endothelin release in smoker rats significantly contributes to increased arterial tone and so contribute to the cardiovascular pathophysiology associated with cigarette smoking, such as increased vascular muscularization, increased contraction, decreased dilation and possibly vasospasm.

Diagnostic and therapeutic challenges in patients with coexistent chronic obstructive pulmonary disease and chronic heart failure

Chronic obstructive pulmonary disease (COPD) and heart failure (CHF) are common conditions. The prevalence of COPD ranges from 20% to 30% in patients with CHF. The diagnosis of CHF can remain unsuspected in patients with COPD, because shortness of breath is attributed to COPD. Measurement of plasma B-type natriuretic peptide (BNP) levels helps to uncover unsuspected CHF in patients with COPD and clinical deterioration. Noninvasive assessment of cardiac function may be preferable to BNP to uncover unsuspected left ventricular (LV) systolic dysfunction in patients with stable COPD. Patients with COPD or CHF develop skeletal muscle alterations that are strikingly similar. Functional intolerance correlates with severity of skeletal muscle alterations but not with severity of pulmonary or cardiac impairment in COPD and CHF, respectively. Improvement of pulmonary or cardiac function does not translate into relief of functional intolerance in patients with COPD or CHF unless skeletal muscle alterations concomitantly regress. The mechanisms responsible for skeletal muscle alterations are incompletely understood in COPD and in CHF. Disuse and low-level systemic inflammation leading to protein synthesis/degradation imbalance are likely to contribute. The presence of COPD impacts on the treatment of CHF, as COPD is still viewed as a contraindication to beta-blockade. Therefore, COPD often deprives patients with CHF due to LV systolic dysfunction of the most beneficial pharmacologic intervention. A large body of data indicates that patients with COPD tolerate well selective beta-blockade that should not be denied to CHF patients with concomitant COPD.

Effect of corticosteroids on hemostasis and pulmonary arterial pressure during chronic obstructive pulmonary disease exacerbation

BACKGROUND

Hemodynamic and hemostatic abnormalities are reportedly frequent in chronic obstructive pulmonary disease (COPD).

OBJECTIVES

We investigated the changes in systolic pulmonary artery pressure (PAPs) and hemostatic status and the effects of systemic steroid treatment (SST) during COPD exacerbation.

METHODS

Consecutive 26 male and 4 female patients as well as 10 controls were enrolled. The nonsteroid treatment (NST) group received standard treatment without steroids, and the other group received additional SST. Initial values of blood gases, spirometry and PAPs, P-selectin, D-dimer and fibrinogen levels, activities of thrombocyte aggregation, antithrombin III (AT III), protein C (PC), protein S, activated PC resistance (APCR), prothrombin time and partial thromboplastin time were obtained and compared with values at day 10.

RESULTS

Improvement in spirometry and blood gases was more prominent with SST. At presentation, patients had higher PAPs, P-selectin, D-dimer and fibrinogen but lower AT III levels than controls. PAPs and fibrinogen levels significantly decreased in the SST group while P-selectin levels further increased in the NST group. The D-dimer level significantly decreased in both groups. Means of AT III, PC and protein S increased in the SST and decreased in the NST group, but only the decrease in PC in the NST group was meaningful. Compared with the controls, AT III levels in the NST group and activated PC resistance in the SST group were significantly decreased. Thrombocyte aggregation tests suggested an incline after 10 days in both groups.

CONCLUSIONS

We suggest that in patients with COPD exacerbation, addition of systemic corticosteroids to treatment results in better outcome in normalization of PAPs, hemostasis, pulmonary functions and blood gases.

Reduced lung function predicts increased fatality in future cardiac events. A population-based study

OBJECTIVE

Moderately reduced lung function in apparently healthy subjects has been associated with incidence of coronary events. However, whether lung function is related to the fatality of the future events is unknown. This study explored whether reduced forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) in initially healthy men is related to the fatality of the future coronary events.

DESIGN

Prospective cohort study.

SETTING

Population-based study from Malmö, Sweden.

SUBJECTS

A total of 5452 healthy men, 28-61 years of age.

MAIN OUTCOME MEASURES

Incidence of first coronary events was monitored over a mean follow-up of 19 years. The fatality of the future events was studied in relation to FEV and FVC.

RESULTS

A total of 589 men suffered a coronary event during follow-up, 165 of them were fatal during the first day. After risk factors adjustment, low FEV or FVC were associated with incidence of coronary events (fatal or nonfatal) and this relationship was most pronounced for the fatal events. Amongst men who subsequently had a coronary event, the case-fatality rates were higher in men with low FEV or FVC. Adjusted for risk factors, the odds ratio for death during the first day was 1.00 (reference), 1.63 (95% CI: 0.9-3.1), 1.86 (1.0-3.5) and 2.06 (1.1-3.9), respectively, for men with FVC in the 4th, 3rd, 2nd, and lowest quartiles (trend: P < 0.05). FEV showed similar relationships with the fatality rates.

CONCLUSION

Apparently healthy men with moderately reduced lung function have higher fatality in future coronary events, with a higher proportion of coronary heart disease deaths and less nonfatal myocardial infarction.

Perioperative cardiac risk: pathophysiology, assessment and management

Cardiac complications are the leading cause of perioperative morbidity and mortality following noncardiac surgery. The annual cost of perioperative cardiovascular events exceeds 20 billion US dollars. A strategic preoperative evaluation holds the potential to reduce perioperative cardiac events and healthcare costs; however, our current understanding of the pathophysiological basis of postoperative acute coronary syndromes is limited. Although significant advances continue to facilitate early and reliable noninvasive detection of high-risk coronary anatomy, the most appropriate interventions remain unclear. Pharmacotherapy, revascularization, safer anesthesia and early detection of perioperative heart failure may all reduce perioperative morbidity and mortality, although the evidence base is incomplete and controversial. A close working relationship between the primary care physician, cardiologist, surgeon and anesthesiologist will facilitate rational, tailored and optimized management decisions that constitute our best opportunity to reduce perioperative cardiovascular risk.

Chronic obstructive pulmonary disease severity and cardiovascular outcomes

OBJECTIVE

To identify predictors of chronic obstructive pulmonary disease (COPD) severity and assess the relation between COPD severity and risk of cardiovascular outcomes.

STUDY DESIGN AND SETTING

A cohort of patients with diagnosed and treated COPD was compiled from the Saskatchewan Health longitudinal databases. We used multivariate modeling to identify predictors of hospitalization for COPD as an indicator of COPD severity, and we used the model to characterize patients according to quintiles of COPD severity. These severity levels were used as independent variables in multivariate models of cardiovascular outcomes.

RESULTS

Determinants of COPD severity included emphysema, recent nebulizer use, home oxygen services, corticosteroid use, frequent bronchodilator use, pneumonia and prior COPD exacerbation. The 20% of patients with the highest COPD severity were 1.27 (CI: 1.07-1.50) times more likely to have arrhythmia, 1.25 (CI: 1.07-1.46) times more likely to have ischemic heart disease, 1.38 (CI: 1.11-1.71) times more likely to have angina, 2.28 (CI: 1.95-2.66) times more likely to have congestive heart failure, and 1.63 (CI: 1.22-2.16) times more likely to die of cardiovascular causes than the least severe 20% of patients.

CONCLUSIONS

Patients with more severe COPD, as defined by our model, had higher cardiovascular morbidity and mortality than patients with less severe COPD.

Chronic obstructive pulmonary disease: effects beyond the lungs

PURPOSE OF REVIEW

This article reviews the systemic effects of chronic obstructive pulmonary disease in general and the musculoskeletal effects and cachexia in particular.

RECENT FINDINGS

Shift in muscle fiber type from I to II, reduction of capillary/mitochondria ratio, reduction of oxidative enzymes and oxidative capacity, alteration in amino acid profile, changes in respiratory muscle dynamics, activation of the ubiquitin-proteosome pathway with loss of contractile proteins are some of the factors found to cause muscle dysfunction in chronic obstructive pulmonary disease. Chemotaxis and capability to produce more reactive oxygen species and to cause extracellular proteolysis are enhanced in neutrophils of chronic obstructive pulmonary disease patients. Tumor necrosis factor-alpha is shown to cause loss of myosin chains in a time and dose-dependent fashion and to induce production of reactive oxygen species through activation of the cyclooxygenase pathway. Inflammation and oxidative stress caused by reactive oxygen species fuel each other. Weight loss due to muscle wasting (cachexia) in chronic obstructive pulmonary disease is not solely related to malnutrition and is an independent predictor of mortality. Causative factors for cachexia include cytokine effects, protein degradation enhanced by increased ubiquination, upregulation of mRNA for key enzymes, increased energy expenditure and neurohormonal effects such as leptin production and an imbalance in anabolic and catabolic hormone homeostasis.

SUMMARY

The findings noted above may well have the common link of inflammation in and beyond the lungs.

Inverse Association between Pulmonary Function and C-Reactive Protein in Apparently Healthy Subjects

RATIONALE

Increased levels of systemic markers of inflammation have been reported in patients with impaired lung function due to obstructive or restrictive lung disease.

OBJECTIVE

We tested the hypothesis that a decline in lung function within the normal range may be associated with a systemic subclinical inflammation.

METHODS

Pulmonary function tests, cardiorespiratory fitness, components of the metabolic syndrome, and high-sensitivity C-reactive protein (CRP) were determined in 1,131 subjects without known pulmonary disease.

MEASUREMENTS AND MAIN RESULTS

Ninety-six of the study participants (8.5%) had FEV(1) of less than 80% of predicted values. There was a strong inverse association between CRP levels and quartiles of FEV(1). The median CRP levels in nonsmoking participants were 2.5, 1.8, 1.7, and 1.3 mg/L in the first, second, third, and forth FEV(1) quartiles, respectively (p < 0.0001). A similar inverse association was present in smoking subjects (median CRP levels were 3.8, 2.3, 2.0, and 1.9 mg/L in the first, second, third, and fourth FEV(1) quartiles, respectively; p < 0.0001). These associations remained highly significant after adjustment for age, sex, components of the metabolic syndrome, and fitness level (p = 0.0005).

CONCLUSIONS

An inverse linear relationship exists between CRP concentrations and measures of pulmonary function in subjects without pulmonary disease and in never-smokers. These results indicate that systemic inflammation may be linked to early perturbations of pulmonary function.

Global Initiative on Obstructive Lung Disease (GOLD) classification of lung disease and mortality: findings from the Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVE

To determine whether a modified Global Initiative on Obstructive Lung Diseases (GOLD) classification of chronic obstructive pulmonary disease (COPD) predicts mortality in a cohort of subjects followed for up to 11 years.

METHODS

We analyzed data from 15,759 adult participants, aged 43-66 years at baseline, in the Atherosclerosis Risk in Communities (ARIC) study. All baseline and follow-up data were available for 15,440 (97.9%) of the initial participants. We classified subjects using a modification of the GOLD criteria for COPD (prebronchodilator forced expiratory volume in 1s (FEV(1)) stratification of disease severity), and added a "restricted" category (FEV(1)/FVC>70% and FVC<80% predicted). We used Cox proportional hazard models to determine the risk of impaired lung function on subsequent mortality, after adjusting for age, race, sex and smoking status.

RESULTS

1242 (8.0%) subjects died by the end of 1997. The overall rate of death was 8.9 per 1000 person years, but varied from 5.4/1000 among normal subjects to 42.9/1000 among subjects with GOLD Stage 3 or 4 COPD. After adjusting for covariates, all GOLD categories, along with the restricted category, predicted a higher risk of death: GOLD Stage 3 or 4, hazard ratio (HR) 5.7, 95% confidence interval (CI) 4.4, 7.3; GOLD Stage 2 HR 2.4, 95% CI 2.0, 2.9; GOLD Stage 1 HR 1.4, 95% CI 1.1, 1.6; GOLD Stage 0 HR 1.5, 95% CI 1.3, 1.8; and restricted HR 2.3, 95% CI 1.9, 2.8.

CONCLUSION

The modified GOLD classification system of COPD predicts mortality in this cohort of middle-aged Americans followed for up to 11 years.

C-reactive protein and mortality in mild to moderate chronic obstructive pulmonary disease

BACKGROUND

Although C-reactive protein (CRP) levels are increased in chronic obstructive pulmonary disease (COPD), it is not certain whether they are associated with adverse clinical outcomes.

METHODS

Serum CRP levels were measured in 4803 participants in the Lung Health Study with mild to moderate COPD. The risk of all-cause and disease specific causes of mortality was determined as well as cardiovascular event rates, adjusting for important covariates such as age, sex, cigarette smoking, and lung function. Cardiovascular events were defined as death from coronary heart disease or stroke, or non-fatal myocardial infarction or stroke requiring admission to hospital.

RESULTS

CRP levels were associated with all-cause, cardiovascular, and cancer specific causes of mortality. Individuals in the highest quintile of CRP had a relative risk (RR) for all-cause mortality of 1.79 (95% confidence interval (CI) 1.25 to 2.56) compared with those in the lowest quintile of CRP. For cardiovascular events and cancer deaths the corresponding RRs were 1.51 (95% CI 1.20 to 1.90) and 1.85 (95% CI 1.10 to 3.13), respectively. CRP levels were also associated with an accelerated decline in forced expiratory volume in 1 second (p < 0.001). The discriminative property of CRP was greatest during the first year of measurement and decayed over time. Comparing the highest and lowest CRP quintiles, the RR was 4.03 (95% CI 1.23 to 13.21) for 1 year mortality, 3.30 (95% CI 1.38 to 7.86) for 2 year mortality, and 1.82 (95% CI 1.22 to 2.68) for > or =5 year mortality.

CONCLUSIONS

CRP measurements provide incremental prognostic information beyond that achieved by traditional markers of prognosis in patients with mild to moderate COPD, and may enable more accurate detection of patients at a high risk of mortality.

The metabolic syndrome in patients with chronic obstructive pulmonary disease

PURPOSE

This study was undertaken to evaluate the presence of the metabolic syndrome in COPD patients who participated in a cardiopulmonary rehabilitation program. The metabolic syndrome is characterized by the presence of abdominal obesity, atherogenic dyslipidemia, raised blood pressure, presence of insulin resistance, and prothrombotic and inflammatory states that predispose to cardiovascular diseases.

METHODS

Thirty-eight COPD patients (age: 66 +/- 7 years, [mean +/- SD], FEV1: 43 +/- 16% predicted) and 34 control participants matched for age and gender are included in this study. The criteria for the identification of the metabolic syndrome include 3 or more of the following features: abdominal obesity (waist circumference: > 102 cm in men, > 88 cm in women), triglycerides levels (>or= 1.69 mmol/L), high-density lipoprotein cholesterol levels (< 1.0 mmol/L in men, < 1.3 mmol/L in women), blood pressure (>or= 130/ >or= 85 mm Hg), and fasting glucose levels (>or= 6.1 mmol/L).

RESULTS

Forty-seven percent of COPD patients and 21% of control participants presented 3 or more determinants of the metabolic syndrome.

CONCLUSIONS

The presence of metabolic syndrome is frequent in patients with COPD who participated in a cardiopulmonary program. Hence, this population should be considered for screening for the metabolic syndrome.

Pulmonary function and abdominal adiposity in the general population

BACKGROUND

The prevalence of obesity is increasing, and there is evidence that obesity, in particular abdominal obesity as a marker of insulin resistance, is negatively associated with pulmonary function. The mechanism for this association and the best marker of abdominal adiposity in relation to pulmonary function is not known.

STUDY OBJECTIVE

We assessed the association between pulmonary function and weight, body mass index (BMI), waist circumference, waist/hip ratio, and abdominal height as markers of adiposity and body fat distribution. We used multiple linear regression to analyze the association of pulmonary function (ie, FEV(1) and FVC) [with maneuvers performed in the sitting position] with overall adiposity markers (ie, weight and BMI) and abdominal adiposity markers, stratified by gender, and adjusted for height, age, race, smoking, and other covariates.

SETTING AND PARTICIPANTS

A random sample of individuals (n = 2,153) from the general population living in western New York state, 35 to 79 years of age.

RESULTS

In women, abdominal height and waist circumference were negatively associated with FEV(1) percent predicted, while all five adiposity markers were negatively associated with FVC percent predicted. In men, all overall and abdominal adiposity markers were inversely associated with FEV(1) percent predicted and FVC percent predicted.

CONCLUSION

These results suggest that abdominal adiposity is a better predictor of pulmonary function than weight or BMI, and investigators should consider it when investigating the determinants of pulmonary function.

The added value of C-reactive protein to clinical signs and symptoms in patients with obstructive airway disease: results of a diagnostic study in primary care

Background

To evaluate the diagnostic accuracy of clinical signs and symptoms, C-reactive protein (CRP) and spirometric parameters and determine their interrelation in patients suspected to have an obstructive airway disease (OAD) in primary care.

Methods

In a cross sectional diagnostic study, 60 adult patients coming to the general practitioner (GP) for the first-time with complaints suspicious for obstructive airway disease (OAD) underwent spirometry. Peak expiratory flow (PEF)-variability within two weeks was determined in patients with inconspicuous spirometry. Structured medical histories were documented and CRP was measured. The reference standard was the Tiffeneau ratio (FEV₁/VC) in spirometry and the PEF-variability. OAD was diagnosed when FEV₁/VC ≤ 70% or PEF-variability > 20%.

Results

37 (62%) patients had OAD. The best cut-off value for CRP was found at 2 mg/l with a diagnostic odds ratio (OR) of 4.4 (95% CI 1.4–13.8). Self-reported wheezing was significantly related with OAD (OR 3.4; CI 1.1–10.3), whereas coughing was inversely related (OR 0.2; CI 0.1–0.7). The diagnostic OR of CRP increased when combined with dyspnea (OR 8.5; 95% CI 1.7–42.3) or smoking history (OR 8.4; 95% CI 1.5–48.9). CRP (p = 0.004), FEV₁ (p = 0.001) and FIV₁ (p = 0.023) were related with the severity of dyspnea. CRP increased with the number of cigarettes, expressed in pack years (p = 0.001).

Conclusion

The diagnostic accuracy of clinical signs and symptoms was low. The diagnostic accuracy of CRP improved in combination with dyspnea and smoking history. Due to their coherence with the severity of dyspnea and number of cigarettes respectively, CRP and spirometry might allow risk stratification of patients with OAD in primary care. Further studies need to be done to confirm these findings.

Chronic Obstructive Pulmonary Disease, inflammation and co-morbidity--a common inflammatory phenotype?

Chronic Obstructive Pulmonary Disease (COPD) is and will remain a major cause of morbidity and mortality worldwide. The severity of airflow obstruction is known to relate to overall health status and mortality. However, even allowing for common aetiological factors, a link has been identified between COPD and other systemic diseases such as cardiovascular disease, diabetes and osteoporosis.

COPD is known to be an inflammatory condition and neutrophil elastase has long been considered a significant mediator of the disease. Pro-inflammatory cytokines, in particular TNF-α (Tumour Necrosis Factor alpha), may be the driving force behind the disease process. However, the roles of inflammation and these pro-inflammatory cytokines may extend beyond the lungs and play a part in the systemic effects of the disease and associated co-morbidities. This article describes the mechanisms involved and proposes a common inflammatory TNF-α phenotype that may, in part, account for the associations.

Change in C-reactive protein levels and FEV1 decline: a longitudinal population-based study

Reduced pulmonary function is an important predictor of cardiovascular morbidity and mortality. The mechanisms underlying this association are unknown but may involve systemic inflammation. We assessed the cross-sectional and longitudinal relationships between C-reactive protein (CRP) levels and forced expiratory volume in 1s (FEV1) and its decline in the general population, over a period of 8.5 years. The analyzes were based on 531 subjects (mean age at baseline: 37+/-7 years, 50% women and 42% non-smokers), recruited at two French centers participating in the European Community Respiratory Health Survey. Lung function was expressed as a percentage of predicted FEV1. CRP was measured centrally, by means of a highly sensitive assay. In cross-sectional analysis, FEV1 as a % of predicted values was negatively associated with serum CRP concentration (P=0.002). Multivariate adjustment did not alter these results (P=0.002). In longitudinal analysis, annual FEV1 decline tended to increase from the lower to the upper tertile for baseline CRP concentration but the association was borderline significant (P=0.14). Mean values of annual FEV1 decline were 26+/-32, 31+/-32, and 34+/-32 ml/year for the lower, middle and upper tertiles of baseline CRP concentration, respectively, after adjusting for potential confounders (P=0.09). Changes in CRP levels during follow-up were associated with annual FEV1 decline. The mean annual FEV1 declines in subjects with increasing CRP, in those with stable CRP and in those with decreasing CRP were 36+/-31, 30+/-31 and 24+/-31 ml/year, respectively (P<0.001). These findings were not affected by adjustment for potential confounders (P=0.002). In conclusion, increases in CRP levels over time were associated with a steeper FEV1 decline.

Reduction of morbidity and mortality by statins, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers in patients with chronic obstructive pulmonary disease

OBJECTIVES

The purpose of this study was to determine if statins (hydroxymethylglutaryl CoA reductase inhibitors [HMG-CoA]), angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor blockers (ARBs) reduce cardiovascular (CV) events and pulmonary morbidity in chronic obstructive pulmonary disease (COPD) patients.

BACKGROUND

Few current COPD therapies alter prognosis. Although statins, ACE inhibitors, and ARBs improve outcomes in CV populations, their benefits in COPD patients both with and without concomitant heart disease has not previously been studied.

METHODS

A time-matched nested case-control study of two population-based retrospective cohorts was undertaken: 1) COPD patients having undergone coronary revascularization (high CV risk cohort); and 2) COPD patients without previous myocardial infarction (MI) and newly treated with nonsteroidal anti-inflammatory drugs (low CV risk cohort). Prespecified outcomes were COPD hospitalization, MI, and total mortality.

RESULTS

These drugs reduced both CV and pulmonary outcomes, with the largest benefits occurring with the combination of statins and either ACE inhibitors or ARBs. This combination was associated with a reduction in COPD hospitalization (risk ratio [RR] 0.66, 95% confidence interval [CI] 0.51 to 0.85) and total mortality (RR 0.42, 95% CI 0.33 to 0.52) not only in the high CV risk cohort but also in the low CV risk cohort (RR 0.77, 95% CI 0.67 to 0.87, and RR 0.36, 95% CI 0.28 to 0.45, respectively). The combination also reduced MI in the high CV risk cohort (RR 0.39, 95% CI 0.31 to 0.49). Benefits were similar when steroid users were included.

CONCLUSIONS

These agents may have dual cardiopulmonary protective properties, thereby substantially altering prognosis of patients with COPD. These findings need confirmation in randomized clinical trials.

The effect of obesity on chronic respiratory diseases: pathophysiology and therapeutic strategies

Sedentary lifestyles and increased pollution brought about by industrialization pose major challenges to the prevention of both obesity and chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD), asthma, obstructive sleep apnea and obesity hypoventilation syndrome. Obesity has emerged as an important risk factor for these respiratory diseases, and in many instances weight loss is associated with important symptomatic improvement. Moreover, obesity may influence the development and presentation of these diseases. In this article, we review the current understanding of the influence of obesity on chronic respiratory diseases and the clinical management of obesity concurrent with asthma, COPD, obstructive sleep apnea or obesity hypoventilation syndrome.

Absence of electrocardiographic findings and improved function with once-daily tiotropium in patients with chronic obstructive pulmonary disease

STUDY OBJECTIVES

To examine electrocardiographic findings after short- and long-term tiotropium therapy in patients with chronic obstructive pulmonary disease (COPD), and to establish previously reported symptomatic efficacy.

DESIGN

Randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

Twelve outpatient investigational centers in the United States.

PATIENTS

One hundred ninety-six patients with COPD.

INTERVENTIONS

Patients received either tiotropium 18 mug once/day or placebo, delivered by the HandiHaler device.

MEASUREMENTS AND MAIN RESULTS

Electrocardiography (predose and 5 min postdose) and 24-hour Holter monitoring were performed at baseline and after 8 and 12 weeks of treatment with tiotropium 18 microg once/day or placebo. Efficacy measures (spirometry, global COPD ratings, scores on the EuroQol Health Questionnaire [EQ-5D], albuterol inhaler as needed) were included to demonstrate that the study population exhibited the characteristic improvements observed in previous tiotropium studies. Mean baseline forced expiratory volume in 1 second (FEV1) was 1.03 L. Mean changes in heart rate from baseline were similar in both groups. No differences were noted in the percentage of patients developing rhythm or conduction abnormalities detected with electrocardiography or Holter monitoring. Frequency of premature beats and mean maximal changes in PR, QRS, QT, QTcB, and QTcF intervals were similar in both groups. No patients developed new-onset QT or QTc intervals greater than 500 msec, and no differences were noted in the percentage of patients developing new QT prolongation less than 30 msec, 30-60 msec, or greater than 60 msec. At 12 weeks, predose and postdose improvements in FEV1 were 184 and 265 ml, respectively, with tiotropium versus placebo (p<0.001). Physician and patient global COPD ratings and the EQ-5D visual analog scale scores were improved with tiotropium (p<0.05); as-needed albuterol was reduced by 25% relative to placebo (p<0.05).

CONCLUSION

Tiotropium provided spirometric and symptomatic benefits in patients with COPD and was not associated with evidence of electrocardiographic changes in heart rate, rhythm, QT intervals, or conduction.

Expression of Toll-like receptor 2 is up-regulated in monocytes from patients with chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterised by pulmonary and systemic inflammation which flare-up during episodes of acute exacerbation (AECOPD). Given the role of Toll-like receptors (TLRs) in the induction of inflammatory responses we investigated the involvement of TLRs in COPD pathogenesis.

METHODS

The expression of TLR-2, TLR-4 and CD14 in monocytes was analyzed by flow cytometry. To study the functional responses of these receptors, monocytes were stimulated with peptidoglycan or lipopolysaccharide and the amounts of TNFalpha and IL-6 secreted were determined by ELISA.

RESULTS

We found that the expression of TLR-2 was up-regulated in peripheral blood monocytes from COPD patients, either clinically stable or during AECOPD, as compared to never smokers or smokers with normal lung function. Upon stimulation with TLR-2 ligand monocytes from COPD patients secreted increased amounts of cytokines than similarly stimulated monocytes from never smokers and smokers. In contrast, the expressions of TLR-4 and CD14 were not significantly different between groups, and the response to lipopolysaccharide (a TLR-4 ligand) stimulation was not significantly different either. At discharge from hospital TLR-2 expression was down-regulated in peripheral blood monocytes from AECOPD patients. This could be due to the treatment with systemic steroids because, in vitro, steroids down-regulated TLR-2 expression in a dose-dependent manner. Finally, we demonstrated that IL-6, whose plasma levels are elevated in patients, up-regulated in vitro TLR-2 expression in monocytes from never smokers.

CONCLUSION

Our results reveal abnormalities in TLRs expression in COPD patients and highlight its potential relationship with systemic inflammation in these patients.

Manifestações sistêmicas na doença pulmonar obstrutiva crônica

A doença pulmonar obstrutiva crônica é progressiva e está relacionada a uma resposta inflamatória anormal dos pulmões à inalação de partículas e/ou gases tóxicos, sobretudo a fumaça de cigarro. Embora acometa primariamente os pulmões, diversas manifestações extrapulmonares relacionadas a esta enfermidade têm sido descritas. O aumento do número de células inflamatórias, que resulta em produção anormal de citocinas pró-inflamatórias, e o desequilíbrio entre a formação de radicais livres e a capacidade antioxidante, resultando em sobrecarga oxidativa, provavelmente são mecanismos envolvidos na inflamação local e sistêmica. Além disso, a diminuição do condicionamento físico secundária às limitações ventilatórias pode estar envolvida no desenvolvimento de alterações musculares. A doença pulmonar obstrutiva crônica apresenta diversas manifestações sistêmicas que incluem a depleção nutricional, a disfunção dos músculos esqueléticos, que contribui para a intolerância ao exercício, e as manifestações relacionadas a co-morbidades comumente observadas nestes pacientes. Essas manifestações têm sido relacionadas à sobrevida e ao estado geral de saúde dos pacientes. Nesse sentido, esta revisão tem como objetivo discutir os achados da literatura relacionados às manifestações sistêmicas da doença pulmonar obstrutiva crônica, ressaltando o papel da inflação sistêmica, e algumas perspectivas de tratamento.

Female smokers beyond the perimenopausal period are at increased risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Recent reports indicate that over the next decade rates of chronic obstructive pulmonary disease (COPD) in women will exceed those in men in the western world, though in most jurisdictions, women continue to smoke less compared with men. Whether female adult smokers are biologically more susceptible to COPD is unknown. This study reviewed the available evidence to determine whether female adult smokers have a faster decline in forced expiratory volume in one second (FEV1) compared with male adult smokers and whether age modifies the relationship between cigarette smoke and lung function decline.

METHODS

A systematic review and a meta-analysis was performed of population-based cohort studies that had a follow-up period of at least 3 years, measured FEV1 on at least two different time points, and presented FEV1 data stratified by gender and smoking status in adults.

RESULTS

Of the 646 potentially relevant articles, 11 studies met these criteria and were included in the analyses (N = 55,709 participants). There was heterogeneity in gender-related results across the studies. However, on average current smokers had a faster annual decline rate in FEV1% predicted compared with never and former smokers. Female current smokers had with increasing age a significantly faster annual decline in FEV1% predicted than male current smokers (linear regression analysis, R2 = 0.56; p = 0.008). Age did not materially affect the rate of decline in FEV1% predicted in male and female former and never smokers (p = 0.775 and p = 0.326, respectively).

CONCLUSION

As female smokers age, they appear to experience an accelerated decline in FEV1% predicted compared with male smokers. Future research powered specifically on gender-related changes in lung function is needed to confirm these early findings.

Plasma fibrinogen and lung function: the CARDIA Study

BACKGROUND

We hypothesized that fibrinogen, as a marker of chronic inflammation, is inversely associated with forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) in healthy persons.

METHODS

The CARDIA cohort started in 1985 and included black and white men and women, aged 18-30, from the general population. Spirometry testing conducted at years 5 and 10 [FVC, FEV(1), and their ratio (FEV(1)/FVC)] was studied relative to plasma fibrinogen levels measured at year 5 (cross-sectional n = 4,040) and at year 7 (longitudinal n = 3,001), controlling for race, sex, age, height, smoking, asthma, body mass index, physical activity, birth control pill use, and alcohol intake.

RESULTS

In cross-sectional analyses, FVC at year 5 was lower by 166 ml (95% confidence interval 116-216 ml) in the highest vs lowest year 5 fibrinogen quartile. At year 10, holding year 5 FVC and change in fibrinogen (year 7-year 5) constant, the difference in FVC between the highest and the lowest year 5 fibrinogen quartiles widened by 67 ml (95% CI 31-103 ml). The corresponding differences for FEV(1) were 166 ml (95% CI 146-253 ml) at year 5 and 45 ml (95% CI 11-80 ml) widening by year 10. The FEV(1)/FVC ratio was unrelated to plasma fibrinogen.

CONCLUSION

These findings are consistent with the hypothesis that fibrinogen, possibly as a marker for chronic low-grade inflammation, is associated with modest deterioration of lung function in healthy young adults.

Reduced lung function in patients with abdominal aortic aneurysm is associated with activation of inflammation and hemostasis, not smoking or cardiovascular disease

OBJECTIVE

Abdominal aortic aneurysms often coexist with reduced lung function and chronic obstructive pulmonary disease (COPD). These conditions are each associated with cigarette smoking, cardiovascular disease, and evidence of increased inflammatory and hemostatic activity. The aim of this study was to determine if these factors accounted for the link between aneurysms and pulmonary disease.

METHODS

The design was a case-control study comparing patients with an asymptomatic abdominal aortic aneurysm with population-based controls without an aneurysm. Aneurysms were diagnosed by ultrasound scan, and pulmonary function was measured by respiratory questionnaire and spirometry. Activation of inflammation and hemostasis was measured by assay of plasma interleukin-6 (IL-6), fibrinogen, von Willebrand factor (vWF), tissue plasminogen activator (tPA) antigen, fibrin D-dimer, and plasmin antiplasmin complexes.

RESULTS

Cases with an abdominal aortic aneurysm (n = 89) had more COPD and worse expiratory lung function as measured by forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) than controls (n = 98) (FEV1, 1.9 vs 2.2 L, P < .01; FEV1/FVC, 0.67 vs 0.75, P < .001) and did not differ in restrictive function (FVC, 2.9 vs 3.0 L, P = .33). Cases also had higher levels of lifetime cigarette smoking (30 vs 24 pack-years, P < 0.01), cardiovascular disease (35% vs 18%, P = .01), plasma fibrinogen (3.5 vs 3.1 g/L, P = .02), IL-6 (2.8 vs 1.8, pg/mL, P < .001), plasmin antiplasmin complexes (596 vs 384 microg/L, P = .01), and D-dimer (442 vs 93 ng/mL, P < .001). On multiple logistic regression analysis of lung function and COPD on the risk of aneurysm, both cigarette smoking and cardiovascular disease had little effect on the relationships. For the markers of activated inflammation and hemostasis, plasmin antiplasmin complexes and D-dimer had the most important confounding effect on the odds ratios. All markers combined had a substantial effect: odds ratio of aneurysm for a one standard deviation decrease in FEV1 fell from 2.3 (95% confidence interval [CI], 1.5 to 3.5) (P < .01) to 1.3 (95% CI, 0.55 to 2.4) (P > or = .05).

CONCLUSION

The association between reduced respiratory function and abdominal aortic aneurysm was not accounted for by cigarette smoking or cardiovascular disease. We hypothesize that activation of inflammation and hemostasis in response to injury may be an important explanation of the association between aneurysm formation and reduced respiratory function. Further studies are required to test this hypothesis.

Can inhaled fluticasone alone or in combination with salmeterol reduce systemic inflammation in chronic obstructive pulmonary disease? Study protocol for a randomized controlled trial [NCT00120978]

Background

Systemic inflammation is associated with various complications in chronic obstructive pulmonary disease including weight loss, cachexia, osteoporosis, cancer and cardiovascular diseases. Inhaled corticosteroids attenuate airway inflammation, reduce exacerbations, and improve mortality in chronic obstructive pulmonary disease. Whether inhaled corticosteroids by themselves or in combination with a long-acting β₂-adrenoceptor agonist repress systemic inflammation in chronic obstructive pulmonary disease is unknown. The Advair Biomarkers in COPD (ABC) study will determine whether the effects of inhaled corticosteroids alone or in combination with a long-acting β₂-adrenoceptor agonist reduce systemic inflammation and improve health status in patients with chronic obstructive pulmonary disease.

Methods/Design

After a 4-week run-in phase during which patients with stable chronic obstructive pulmonary disease will receive inhaled fluticasone (500 micrograms twice daily), followed by a 4-week withdrawal phase during which all inhaled corticosteroids and long acting β₂-adrenoceptor agonists will be discontinued, patients will be randomized to receive fluticasone (500 micrograms twice daily), fluticasone/salmeterol combination (500/50 micrograms twice daily), or placebo for four weeks. The study will recruit 250 patients across 11 centers in western Canada. Patients must be 40 years of age or older with at least 10 pack-year smoking history and have chronic obstructive pulmonary disease defined as forced expiratory volume in one second to vital capacity ratio of 0.70 or less and forced expiratory volume in one second that is 80% of predicted or less. Patients will be excluded if they have any known chronic systemic infections, inflammatory conditions, history of previous solid organ transplantation, myocardial infarction, or cerebrovascular accident within the past 3 months prior to study enrolment. The primary end-point is serum C-reactive protein level. Secondary end-points include circulating inflammatory cytokines such as interleukin-6 and interleukin-8 as well as health-related quality of life and lung function.

Discussion

If inhaled corticosteroids by themselves or in combination with a long-acting β₂-adrenoceptor agonist could repress systemic inflammation, they might greatly improve clinical prognosis by reducing various complications in chronic obstructive pulmonary disease.

Changing the burden of COPD mortality

COPD is a major cause of mortality and morbidity worldwide with an estimated 2.75 million deaths in 2000 (fourth leading cause of death). In addition to the considerable morbidity and mortality associated with COPD, this disease incurs significant healthcare and societal costs. Current COPD guidelines acknowledge that the following can improve COPD mortality: smoking cessation; long-term oxygen therapy; and lung volume reduction surgery in small subsets of COPD patients. To date, no randomized controlled trials have demonstrated an effect of pharmacological treatment on mortality, although several observational studies suggest that both long-acting bronchodilators and inhaled corticosteroids may provide a survival benefit. The possibility that these treatments reduce mortality is being investigated in ongoing large-scale clinical trials.

Neurohumoral activation as a link to systemic manifestations of chronic lung disease

COPD is a major cause of death and disability worldwide. Treatment of COPD improves lung function but is unlikely to slow the steady downhill course of the disease or reduce mortality. In COPD, numerous abnormalities can be found outside the lung. These include systemic inflammation, cachexia, and skeletal muscle dysfunction. Thus, COPD has been called a systemic disease. Convincing data demonstrate that COPD causes neurohumoral activation. By precedents derived from chronic heart failure and other diseases characterized by neurohumoral activation, we propose that the negative consequences of neurohumoral activation, namely inflammation, cachexia, effects on ventilation, and skeletal muscle dysfunction, give rise to a self-perpetuating cycle that contributes to the pathogenesis of COPD, and which may involve respiratory muscle dysfunction as well as systemic inflammation. This concept may further help explain the increased cardiovascular morbidity and mortality in COPD patients. Currently, little is known about the effect of treatments directed at neurohumoral activation and COPD. As this aspect of COPD becomes better understood, new insights may direct novel therapeutic approaches.

Hospital use for COPD patients during the last few years of their life

Little is known about what happens to COPD patients during their final years of life, in particular in terms of hospital use. We linked the Swedish Mortality and Inpatient Registers to examine this research question during the period 1987-2000. In year 2000, 2331 fatalities were diagnosed with COPD as the underlying cause of death. About 3% of individuals had not been admitted to hospital at all prior to their death, whereas 15% had never been admitted for COPD (but for other reasons). More than 68% of all COPD admissions and 74% of all days in hospital occurred in the 3.5 years before death, indicating longer stays closer to death. The last 6 months of life accounted for 22% and 28% of all COPD admissions and days, respectively. Other causes accounted for nearly 50% of all admissions, with a more limited increase during the final years. In conclusion, there is a very variable hospital use among these COPD patients. Use increases almost exponentially as the end approaches. Finally, COPD patients often have a number of concomittant diseases which may affect diagnosis and healthcare resource use. The economic and policy implications of these main findings need to be further examined.

Airway and systemic inflammation and decline in lung function in patients with COPD

STUDY OBJECTIVES

Patients with COPD experience lower airway and systemic inflammation, and an accelerated decline in FEV1. There is no evidence on whether this inflammation changes over time, or if it is associated with a faster decline in FEV1.

PATIENTS AND DESIGN

A cohort of 148 COPD patients (100 men) was monitored daily for a median of 2.91 years (interquartile range [IQR], 2.1 to 4.8). At recruitment, median age was 68.5 years (IQR, 62.5 to 73.6) and FEV1 as percentage of predicted (FEV1%Pred) was 38.5% (IQR, 27.7 to 50.3).

RESULTS

During the study, the patients experienced 1,389 exacerbations, a median of 2.52/yr (IQR, 1.48 to 3.96) and FEV1 declined by 40.2 mL/yr or as FEV1%Pred by 1.5%/yr. Concerning inflammatory markers, sputum interleukin (IL)-6 rose by 9 pg/mL/yr, sputum neutrophil count rose by 1.64 x 10(6) cells per gram sputum per year, an plasma fibrinogen rose by 0.10 g/L/yr (all p < 0.05). Patients with frequent exacerbations (> or = 2.52/yr) had a faster rise over time in plasma fibrinogen and sputum IL-6 of 0.063 g/L/yr (p = 0.046, n = 130) and 29.5 pg/mL/yr (p < 0.001, n = 98), respectively, compared to patients with infrequent exacerbations (< 2.52/yr). Using the earliest stable (nonexacerbation) measured marker, patients whose IL-6 exceeded the group median had a faster FEV1%Pred decline of 0.42%/yr (p = 0.018). Similarly, a high neutrophil count or fibrinogen were associated with a faster FEV1%Pred decline of 0.97%/yr (p = 0.001) and 0.40%/yr (p = 0.014), respectively.

CONCLUSIONS

In COPD, airway and systemic inflammatory markers increase over time; high levels of these markers are associated with a faster decline in lung function.

C-reactive protein in patients with COPD, control smokers and non-smokers

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) have raised serum levels of C reactive protein (CRP). This may be related directly to COPD and its associated systemic inflammation or secondary to other factors such as concomitant ischaemic heart disease (IHD) or smoking status. The aim of this study was to evaluate IHD and smoking as potential causes of raised CRP levels in COPD and to test the association between inhaled corticosteroid (ICS) use and serum CRP levels.

METHODS

Cross sectional analyses comparing cohorts of 88 patients with COPD, 33 smokers (S), and 38 non-smoker (NS) controls were performed. Clinical assessments included a complete medical history, pulmonary function, 6 minute walk test (6MWT), cardiopulmonary exercise test, and high sensitivity serum CRP measurements.

RESULTS

Serum CRP levels were significantly higher in patients with COPD (5.03 (1.51) mg/l) than in controls (adjusted odds ratio 9.51; 95% confidence interval 2.97 to 30.45) but were similar in the two control groups (S: 2.02 (1.04) mg/l; NS: 2.24 (1.04) mg/l). There was no clinical or exercise evidence of unstable IHD in any of the subjects. CRP levels were lower in COPD patients treated with ICS than in those not treated (3.7 (3.0) mg/l v 6.3 (3.6) mg/l); this association was confirmed in an adjusted regression model (p<0.05).

CONCLUSION

CRP levels are raised in COPD patients without clinically relevant IHD and independent of cigarette smoking, and reduced in patients with COPD using ICS. CRP may be a systemic marker of the inflammatory process that occurs in patients with COPD.

Gamma-glutamyl transferase and airflow obstruction in middle-aged men

BACKGROUND

A relationship between pulmonary dysfunction and cardiovascular mortality has been described. The mechanism responsible for the relationship remains largely unknown.

METHODS

The association between airflow obstruction and selected cardiovascular risk factors including gamma-glutamyl transferase (gamma-GT) and total homocysteine was analyzed cross-sectionally in 954 middle-aged men. Airflow obstruction was assessed with %FEV(1) (FEV(1)/FVC).

RESULTS

Serum gamma-GT and white blood cell (WBC) count were higher in subjects with airflow obstruction (%FEV(1)<70%) than in those without it (76.9+/-164.3 IU/L vs. 55.9+/-67.9 IU/L, P=0.030; 6290+/-1590/microL vs. 5590+/-1410/microL, P<0.001). Airflow obstruction was not associated with body mass index, total cholesterol, triglycerides, fasting glucose, or systolic blood pressure, but there was a marginal association with total homocysteine. In a logistic regression analysis adjusted for smoking status and alcohol consumption, the odds ratios (95% confidence interval) of Delta100 IU/L increase in gamma-GT and Delta1000/microL increase in WBC count for the presence of airflow obstruction were 1.20 (0.97-1.48, P=0.090) and 1.21 (1.02-1.44, P=0.036), respectively.

CONCLUSIONS

Airflow obstruction was associated with gamma-GT. The association was independent of alcohol consumption category, but was attenuated by the addition of cigarette smoking status.