Inflammatory response and body composition in chronic obstructive pulmonary disease

The CRP genotype, serum levels and lung function in men: the Caerphilly Prospective Study

Systemic CRP (C-reactive protein) has been associated with impaired lung function. A causal relationship would increase the value of CRP as both a diagnostic and therapeutic tool. We assessed the association between lung function parameters, circulating CRP and CRP polymorphisms using Mendelian randomization in efforts to attribute causality to known associations. Spirometric parameters of FEV1 (forced expiratory volume in 1 s) and FVC (forced vital capacity) were determined in 2173 men participating in the Caerphilly Prospective Study. Lung function measures on 1021 participants were available at follow-up (mean, 16.8 years later). Serum CRP levels were measured at baseline, and three CRP polymorphisms were analysed. Haplotype analysis was performed. Serum CRP levels at baseline were inversely associated with contemporaneous FEV1 and FVC as well as at follow-up (P<0.001) even after adjustment for conventional confounders. Serum CRP was associated with FEV1 decline (P=0.04). All three CRP polymorphisms (rs1800947, rs1130864 and rs1205) predicted serum CRP; however, there were no clear associations of the polymorphisms or haplotypes with lung function or with lung function decline. In conclusion, serum CRP was associated with lung function cross-sectionally; however, CRP polymorphisms were not associated with lung function or decline, suggesting that the CRP-lung function relationship is due to reverse causality, an unmeasured confounding factor or only has a modest causal effect.

Obstructive sleep apnea in chronic obstructive pulmonary disease patients

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) represent two of the most prevalent chronic respiratory disorders and cardiovascular diseases are major co-morbidities in both. Co-existence of both disorders (overlap syndrome) occurs in 1% of adults and overlap patients have worse nocturnal hypoxemia and hypercapnia than COPD and OSA patients alone. The present review discusses recent data concerning the pathophysiological and clinical significance of the overlap syndrome.

RECENT FINDINGS

The severity of obstructive ventilatory impairment and hyperinflation, especially the inspiratory capacity to total lung capacity (TLC) ratio, correlates with the severity of sleep-related breathing disturbances. Early treatment with continuous positive airway pressure (CPAP) improves survival, reduces hospitalization and pulmonary hypertension, and also reduces hypoxemia. Evidence of systemic inflammation and oxidative stress in COPD and sleep apnea provides insight into potential interactions between both disorders that may predispose to cardiovascular disease. Long-term outcome studies of overlap patients currently underway should provide further evidence of the clinical significance of the overlap syndrome.

SUMMARY

Studies of overlap syndrome patients at a clinical, physiological and molecular level should provide insight into disease mechanisms and consequences of COPD and sleep apnea, in addition to identifying potential relationships with cardiovascular disease.

Chronic obstructive pulmonary disease (COPD) and old age?

Chronic obstructive pulmonary disease (COPD) in old age is an increasing problem. Understanding the features of COPD in older patients is important in order to introduce effective interventions and to inform efforts for health resource allocation. Features of importance to old age include increased prevalence of COPD in non-smokers and rise in the rate of systemic comorbidities. In addition, acute exacerbations in older patients have poorer outcome, manifesting by increase in the rate of hospitalisation, greater length of stay, increase of the rate of re-hospitalisation and in mortality rate. Impaired cognitive functions as well as problems affecting hand joints make using inhaled medications less reliable which leads to further deterioration of outcome of care. Even for those who are competent in using inhalers, the evidence for their efficacy in older patients is not certain.

Radiographic emphysema predicts low bone mineral density in a tobacco-exposed cohort

RATIONALE

Studies demonstrating an association between chronic obstructive pulmonary disease and low bone mineral density (BMD) implicate factors distinct from treatments and severity of lung disease in the pathogenesis of osteoporosis. Whereas emphysema has been independently associated with vascular disease and other comorbidities, its association with BMD has not been well studied.

OBJECTIVES

We explored the associations of BMD with computed tomography (CT) measures of emphysema and other risk factors in current and former smokers.

METHODS

One hundred ninety subjects completed a CT scan, pulmonary function testing, questionnaires, and dual x-ray absorptiometry measurements of hip and lumbar spine BMD. Subjects were classified as having normal BMD, osteopenia, or osteoporosis. Demographic, physiologic, and radiographic characteristics were compared and the association of BMD with radiographic emphysema, airflow obstruction, and osteoporosis risk factors was assessed.

MEASUREMENTS AND MAIN RESULTS

No difference existed in age, tobacco exposure, oral steroid use, or physical activity across BMD categories. Both osteopenia and osteoporosis were associated with the presence of airflow obstruction, inhaled corticosteroid use, and female sex, and demonstrated a significant relationship with the presence of visual emphysema (P = 0.0003). Quantitative emphysema, but not CT-measured indices of airway wall thickness, was inversely associated with BMD. Visual emphysema alone was a significant predictor of osteopenia/osteoporosis (odds ratio = 2.55; 95% confidence interval, 1.24-5.25) in a model including obstruction severity, age, sex, and inhaled and oral steroid use.

CONCLUSIONS

Radiographic emphysema is a strong, independent predictor of low BMD in current and former smokers. This relationship suggests a common mechanistic link between emphysema and osteopenia/osteoporosis.

Association between body composition and pulmonary function in elderly people: the Korean Longitudinal Study on Health and Aging

The age-related increase in body fat and decrease in muscle mass are associated with increased morbidity in elderly populations. Pulmonary function also decreases with age, but no study has investigated whether regional body composition is associated with pulmonary function in an older population. The Korean Longitudinal Study on Health and Aging is a community-based cohort study of people aged > 65 years selected by random stratified sampling. Anthropometrics, biochemical factors, and lung function by spirometry were evaluated in 439 men (mean age of 75.9 ± 8.6 years) and 561 women (mean age of 76.0 ± 8.8 years). Dual-energy X-ray absorptiometry (DXA) was performed to assess the whole and regional body composition. Computed tomography (CT) was also used to measure fat or muscle distribution at the abdominal and mid-thigh levels. Although pulmonary function and muscle mass were inversely related to age, fat mass was not. After adjusting for age, height, BMI, smoking and exercise status, and high sensitivity C-reactive protein (hsCRP), fat mass in trunk or central area was inversely associated with lung function in both sexes (P < 0.01). Men with more muscle in trunk and mid-thigh level had better lung function (P < 0.01). The results of this community-based study show that regional body composition is significantly associated with lung function. Augmentation of muscle in the trunk and low extremity in men, and reduction of fat in the trunk and upper body in men and women may be helpful in maintaining lung function in the elderly population.

Metabolic phenotype and adipose tissue inflammation in patients with chronic obstructive pulmonary disease

Potential links between metabolic derangements and adipose tissue (AT) inflammation in patients with chronic obstructive pulmonary disease (COPD) are unexplored. We investigated AT expressions of interleukin (IL)-6, tumor necrosis factor (TNF)-α, CD68 (macrophage cell surface receptor), caspase-3, and Bax, and their relationships to the metabolic phenotype in nine cachectic, 12 normal-weight, 12 overweight, and 11 obese patients with COPD (age 62.3 ± 7.2 years). With increasing body mass index, increases in AT expressions of IL-6, TNF-α, and CD68 were observed (P < .001; P = .005; P < .001, resp.), in association with reduced insulin sensitivity (P < .001). No differences were observed between cachectic and normal-weight patients in AT expressions of inflammatory or proapoptotic markers. Adipose tissue CD68 and TNF-α expressions predicted insulin sensitivity independently of known confounders (P = .005; P = .025; R² = 0.840). Our results suggest that AT inflammation in obese COPD patients relates to insulin resistance. Cachectic patients remain insulin sensitive, with no AT upregulation of inflammatory or proapoptotic markers.

Current and potential roles of ghrelin in clinical practice

Ghrelin is a novel GH-releasing peptide, which has been identified as an endogenous ligand for GH-secretagogue receptor. Ghrelin is mainly secreted by the stomach and plays a critical role in a variety of physiological processes including endocrine, metabolic, cardiovascular, immunological, and other actions. Ghrelin stimulates food intake via hypothalamic neurons and causes a positive energy balance and body weight gain by decreasing fat utilization and promoting adiposity. Given the multiple effects of ghrelin, its potential clinical applications have been evaluated in various conditions. Preliminary trials have shown that it may prove valuable in the management of disease-induced cachexia. Ghrelin may improve the wasting syndrome through GH-dependent or GH-independent effects. Moreover, ghrelin may play a role in the management of disorders of gut motility and obesity. Finally, other potential clinical applications of ghrelin include the treatment of patients with diabetes mellitus, infections, rheumatological diseases or GH deficiency and the diagnosis of this hormonal disorder.

Stress and inflammation: a biobehavioral approach for nursing research

Despite known advantages, the use of biobehavioral approaches in nursing research remains limited. The purposes of this article are to (1) present applications of stress and inflammation in various health conditions as examples of biobehavioral concepts and (2) stimulate similar applications of biobehavioral concepts in future nursing research. Under a biobehavioral conceptual framework, studies on stress and selective inflammatory biomarkers in cardiovascular, cancer, and pulmonary health are reviewed and summarized. Inflammation underlies many diseases, and stress is a significant source of increased inflammation. Biobehavioral concepts of stress and inflammation are highly relevant to nursing research concerned with health-related issues. Diverse biobehavioral concepts are readily applicable and should be utilized in nursing research with children and adults. To stimulate further biobehavioral research, more training and resources for nurse scientists, more unified conceptual definitions and biobehavioral conceptual frameworks, rigorous and expanded methodologies, and more collaboration are essential.

Systemic effects of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is associated with important extrapulmonary, or systemic, effects. There is systemic as well as pulmonary inflammation in COPD and this, together with systemic oxidative stress, contributes to their development. Skeletal muscle dysfunction contributes to exercise limitation. There is a loss of muscle mass and a reduction in the proportion of type 1 fibers. Sedentarism, hypoxia, corticosteroid therapy, nutritional depletion and systemic inflammation may contribute to its development. Weight loss is another important effect. It is associated with a worse prognosis, which changes with therapy and may be due to reductions in calorie intake, changes in intermediate metabolism and effects of systemic inflammation. Cardiovascular disease is a frequent cause of death in COPD and coronary artery disease, left ventricular failure and arrhythmias are systemic effects of COPD, as well as comorbidities sharing a common etiology. Exacerbations of COPD may increase the risk of coronary events by increasing the level of systemic inflammation. Osteoporosis is more common in COPD (even after adjusting for corticosteroid usage) and may be due to a combination of inactivity and the effects of systemic inflammation. COPD is also associated with systemic endothelial dysfunction and CNS abnormalities (including depression), which may also be due to the effects of systemic inflammation. These systemic effects respond to COPD treatments, including pulmonary rehabilitation, nutritional supplementation and inhaled corticosteroids, as well as specific drugs, such as bisphosphonates or diuretics. There is growing evidence that novel approaches, such as the use of statins, may also be of value.

Investigating activity in hospitalized patients with chronic obstructive pulmonary disease: a pilot study

OBJECTIVE

This study examined therapeutic mobility activity, and investigated whether serum levels of inflammatory biomarkers interleukin (IL)-6 and IL-10 varied between periods of rest and activity.

METHODS

This observational, exploratory study took place in a medical intensive care unit and in stepdown units at an urban, academic medical center managed by intensivists. Our sample included 17 adults with exacerbations of chronic obstructive pulmonary disease (COPD).

RESULTS

Our results indicate that activity can occur for about 20 minutes, early during a hospitalization, among critically ill adults with COPD exacerbations, and activity can progress safely over 2 days in an intensive-care or stepdown setting. Physical activity was low in intensity, as measured by actigraphy.

CONCLUSION

Although no significant differences were evident between serum inflammatory biomarkers at rest vs after activity in this small sample, trend-related data indicate that low-intensity activity has the potential to alter the inflammatory profile of hospitalized COPD adults.

Predictors of mortality in elderly subjects with obstructive airway disease: the PILE score

PURPOSE

To identify significant covariates in addition to spirometry that predict mortality in elderly subjects with obstructive airway disease (OAD).

METHODS

Two hundred sixty-eight (268) participants with OAD from the Health, Aging and Body Composition study, a community-based observational cohort of well-functioning elderly aged 70-79 years, were followed on average for 6.1 years. Covariates related to pulmonary and physical function, comorbidity, demographics, and three inflammatory markers (interleukin-6, tumor necrosis factor-alpha, C-reactive protein) were evaluated for their association with all-cause mortality (31%) by means of Kaplan Meier analysis and Cox proportional hazards modeling.

RESULTS

Percent predicted forced expiratory volume in one second (PPFEV1; hazard ratio [HR] = 2.03, p < 0.0001), knee extensor strength (HR = 1.36, p = 0.0002), interleukin-6 (HR = 1.37, p = 0.0002) and 400 m corridor walk time (HR = 1.24, p = 0.008) significantly predicted mortality. A multidimensional index, the PILE score, was constructed from PPFEV(1), interleukin-6, and knee extensor strength. Each one-point increase in PILE score (range: 1-10) was associated with a 30% increase in mortality (95% confidence interval: 0.16-0.47) after adjusting for age, race, gender, smoking, and comorbidity, resulting in a 10.4-fold higher risk of death between the highest and lowest risk category.

CONCLUSIONS

Subjects with OAD have a wide gradient of risk for mortality that can potentially be incorporated in clinical decision making.

Structural and functional changes of peripheral muscles in chronic obstructive pulmonary disease patients

PURPOSE OF REVIEW

The purpose of this review is to identify new advances in our understanding of skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS

Recent studies have confirmed the relevance of muscle dysfunction as an independent prognosis factor in COPD. Animal studies have shed light on the molecular mechanisms governing skeletal muscle hypertrophy/atrophy. Recent evidence in patients with COPD highlighted the contribution of protein breakdown and mitochondrial dysfunction as pathogenic mechanisms leading to muscle dysfunction in these patients.

SUMMARY

COPD is a debilitating disease impacting negatively on health status and the functional capacity of patients. COPD goes beyond the lungs and incurs significant systemic effects among which muscle dysfunction/wasting is one of the most important. Muscle dysfunction is a prominent contributor to exercise limitation, healthcare utilization and an independent predictor of morbidity and mortality. Gaining more insight into the molecular mechanisms leading to muscle dysfunction/wasting is key for the development of new and tailored therapeutic strategies to tackle skeletal muscle dysfunction/wasting in COPD patients.

Local inflammation occurs before systemic inflammation in patients with COPD

BACKGROUND AND OBJECTIVE

COPD is associated not only with an abnormal inflammatory response in the lung but also with systemic inflammation, including systemic oxidative stress, activation of circulating inflammatory cells and increased circulating levels of inflammatory cytokines. Understanding the nature and course of systemic inflammation in COPD is important given the potential for anti-inflammatory therapy. This study explored whether local and systemic inflammation occur concurrently in patients with COPD.

METHODS

Forty-four patients with stable COPD, 10 smoking controls and 10 non-smoking controls were enrolled in this observational study. Induced sputum and peripheral blood samples were obtained simultaneously for measurement of inflammatory cell numbers and the concentrations of IL-6 and CRP.

RESULTS

The total number of cells in the sputum total cell number, percentage of neutrophils and the concentration of IL-6 were significantly higher in smoking controls and patients with COPD than in non-smoking controls (P < 0.05 and P < 0.01, respectively). As the disease stage progressed, airway inflammatory cells and IL-6 levels increased. CRP levels in sputum were significantly higher in stage II, III and IV COPD patients than in smoking and non-smoking controls (P < 0.01). However, the peripheral WCC and percentage of neutrophils were similar in patients with COPD, smoking and non-smoking controls. Circulatory concentrations of IL-6 and CRP in stages III and IV COPD patients were significantly higher than in smoking and non-smoking controls (P < 0.05 and P < 0.01, respectively). Additionally, there were positive correlations between sputum and blood IL-6 and CRP levels (r = 0.566, P < 0.01 and r = 0.443, P < 0.01, respectively).

CONCLUSIONS

The increase in the inflammatory cell population and IL-6 and CRP levels in the airway may occur earlier than in the peripheral blood, and reflect the degree of airflow limitation better than do peripheral blood measurements. Systemic inflammation may be present in patients with severe or very severe COPD.

Elevated TNFalpha production in whole blood in patients with severe COPD: the potential link to disease severity

OBJECTIVE

The relationship between tumour necrosis factor-alpha (TNFalpha), severity of pulmonary disease and nutritional depletion in chronic obstructive pulmonary disease (COPD) remains unclear. We aimed to clarify the role of lipopolysaccharide (LPS) as a potential stimulus of cytokine production and the role of these cytokines in the alteration of body composition in patients with different degrees of COPD.

PATIENTS AND METHODS

We studied 29 weight-stable out-patients with different severites of COPD who had no evidence of recent infection or significant co-morbidity. Baseline serum TNFalpha levels and TNFalpha response to LPS in whole blood were measured in patients and 20 aged matched controls.

RESULTS

Serum TNFalpha was significantly elevated in patients versus controls (2.1 +/- 0.3 vs. 1.1 +/- 0.1 pg/ml, mean +/- SEM, P = 0.007). In patients with COPD, we found a significant correlation between serum TNFalpha levels and disease severity, assessed as FEV(1) %predicted (r = 0.49, P = 0.02). Response to lipopolysaccharide did not differ significantly between patients and controls. However, within the patient group those with more severe disease (FEV(1) < or = 30% predicted, n = 12) had an enhanced response compared to patients with mild-to-moderate disease (all P < 0.05 for LPS > 1 ng/ml). Spontaneous TNFalpha production was 5.0 times higher in patients with severe COPD compared to mild-to-moderate COPD (P = 0.02). There was no relation between body composition and serum TNFalpha or TNFalpha response to LPS.

CONCLUSION

Increasing airflow obstruction and hypercapnia are associated with an enhanced TNFalpha response in COPD.

Impact of chronic obstructive pulmonary disease (COPD) on attention functions

The present study investigates the influence of COPD on attention functions, learning, and logical thinking. Therefore, 60 COPD patients and 60 healthy controls were recruited into a cross-sectional study and underwent extensive neuropsychological testing. The Attention Network Test was used for assessment of tonic and phasic alertness, orienting, and executive attention. Logical thinking and learning were determined with the Standard Progressive Matrices and the Verbal and Nonverbal Learning Test, respectively. Significant group differences were found in phasic alertness (p=0.001) and orienting (p=0.01) but not in executive attention. In addition overall reaction time was significantly slower in the COPD group (p=0.001). Further group differences were found in verbal (p<0.001) and visual learning (p<0.001) and logical thinking (p<0.001). Regression analysis revealed significant correlations for age (p=0.024) and blood carbon dioxide levels (p=0.043) in reaction time, a correlation for age and orienting (p=0.019) and finally for age (p=0.011) as well as for blood carbon dioxide values (p=0.048) and performance in logical thinking. Results are indicating a global impairment in cognitive functions of COPD patients which is negatively influenced by accelerated aging and increasing with disease severity.

Targeted treatment in COPD: a multi-system approach for a multi-system disease

Chronic obstructive pulmonary disease is a varied condition when examined from a number of different perspectives including factors which influence disease development, pathological process and clinical features. There may be a complex interaction between the degree by which each of these processes influences the development of COPD and the subsequent clinical phenotype with which the patient presents. The varied host response and subsequent clinical phenotype has generated much interest in recent years. It is possible that failure of treatment to impact on mortality and reverse the disease process is because of the heterogeneous nature of the condition. Identification and targeted treatment of clinical and pathological phenotypes within the broad spectrum of COPD may therefore improve outcome. This article will review previous work which has attempted to phenotype COPD and identify if specific treatment for these phenotypes has been shown to be of benefit. It will examine the work on pathological processes and clinical manifestations, both pulmonary and systemic, and will focus on pharmacological therapies.

The influence of radiographic phenotype and smoking status on peripheral blood biomarker patterns in chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is characterized by both airway remodeling and parenchymal destruction. The identification of unique biomarker patterns associated with airway dominant versus parenchymal dominant patterns would support the existence of unique phenotypes representing independent biologic processes. A cross-sectional study was performed to examine the association of serum biomarkers with radiographic airway and parenchymal phenotypes of COPD.

Methodology/Principal Findings

Serum from 234 subjects enrolled in a CT screening cohort was analyzed for 33 cytokines and growth factors using a multiplex protein array. The association of serum markers with forced expiratory volume in one second percent predicted (FEV1%) and quantitative CT measurements of airway thickening and emphysema was assessed with and without stratification for current smoking status. Significant associations were found with several serum inflammatory proteins and measurements of FEV1%, airway thickening, and parenchymal emphysema independent of smoking status. The association of select analytes with airway thickening and emphysema was independent of FEV1%. Furthermore, the relationship between other inflammatory markers and measurements of physiologic obstruction or airway thickening was dependent on current smoking status.

Conclusions/Significance

Airway and parenchymal phenotypes of COPD are associated with unique systemic serum biomarker profiles. Serum biomarker patterns may provide a more precise classification of the COPD syndrome, provide insights into disease pathogenesis and identify targets for novel patient-specific biological therapies.

Skeletal muscle dysfunction in COPD: clinical and laboratory observations

COPD (chronic obstructive pulmonary disease), although primarily a disease of the lungs, exhibits secondary systemic manifestations. The skeletal muscles are of particular interest because their function (or dysfunction) not only influences the symptoms that limit exercise, but may contribute directly to poor exercise performance. Furthermore, skeletal muscle weakness is of great clinical importance in COPD as it is recognized to contribute independently to poor health status, increased healthcare utilization and even mortality. The present review describes the current knowledge of the structural and functional abnormalities of skeletal muscles in COPD and the possible aetiological factors. Increasing knowledge of the molecular pathways of muscle wasting will lead to the development of new therapeutic agents and strategies to combat COPD muscle dysfunction.

Chronic obstructive pulmonary disease and obstructive sleep apnea: overlaps in pathophysiology, systemic inflammation, and cardiovascular disease

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea syndrome represent two of the most prevalent chronic respiratory disorders in clinical practice, and cardiovascular diseases represent a major comorbidity in each disorder. The two disorders coexist (overlap syndrome) in approximately 1% of adults but asymptomatic lower airway obstruction together with sleep-disordered breathing is more prevalent. Although obstructive sleep apnea syndrome has similar prevalence in COPD as the general population, and vice versa, factors such as body mass index and smoking influence relationships. Nocturnal oxygen desaturation develops in COPD, independent of apnea/hypopnea, and is more severe in the overlap syndrome, thus predisposing to pulmonary hypertension. Furthermore, upper airway flow limitation contributes to nocturnal desaturation in COPD without apnea/hypopnea. Evidence of systemic inflammation in COPD and sleep apnea, involving C-reactive protein and IL-6, in addition to nuclear factor-kappaB-dependent pathways involving tumor necrosis factor-alpha and IL-8, provides insight into potential basic interactions between both disorders. Furthermore, oxidative stress develops in each disorder, in addition to activation and/or dysfunction of circulating leukocytes. These findings are clinically relevant because systemic inflammation may contribute to the pathogenesis of cardiovascular diseases and the cell/molecular pathways involved are similar to those identified in COPD and sleep apnea. However, the pathophysiological and clinical significance of systemic inflammation in COPD and sleep apnea is not proven, and thus, studies of patients with the overlap syndrome should provide insight into the mechanisms of systemic inflammation in COPD and sleep apnea, in addition to potential relationships with cardiovascular disease.

The relationship between adipokines, body composition, and bone density in men with chronic obstructive pulmonary disease

Osteoporosis is common in patients with chronic obstructive pulmonary disease (COPD). Data regarding the relationship between adipokines and bone mineral density (BMD) in this population is lacking. The purpose of this pilot study was to determine associations between the adipokines tumor necrosis factor-alpha (TNF-α), leptin, adiponectin and resistin, body composition, and BMD in men with severe COPD. This was a cross-sectional study of men with severe COPD who visited the University of Colorado Hospital COPD Center. Bone density and parameters of body composition were measured by dual-energy X-ray absorptiometry. Twenty-three men were included (mean age = 66 years, mean percent predicted forced expiratory volume in one second = 32%). On bivariate analysis, there was no association between TNF-α and BMD. Parameters of body composition and serum concentrations of leptin and adiponectin were significantly associated with total hip and spine bone density. However, with partial correlation analysis, total body mass was the only independent predictor of total hip BMD, explaining approximately 50% of the variability. Overall, 18 out of 23 men enrolled (78%) had low bone density by T-score, and nine (39%) were classified as having osteoporosis. The men with osteoporosis had lower parameters of body composition, lower mean serum leptin concentrations, and a greater impairment in measures of lung function compared to the men without osteoporosis. We conclude that the effect of adipokines on BMD does not appear to be independent of body mass. However, larger studies are needed to further evaluate the relationship between adipokines, body weight, and BMD in patients with COPD.

The “Oil Well Analogy” as a Comprehensive Interpretation of Factors Leading to Muscle Injury and Wasting

Muscle abnormalities involved in chronic obstructive pulmonary disease (COPD) or the changes leading to muscle wasting and cachexia in neoplastic patients have a remarkable clinical impact, but their study is complex and findings are sometimes paradoxical. In this review, the main factors influencing muscle wasting and muscle abnormalities found in chronic diseases such as COPD are regarded in the light of a comprehensive approach. All this changes work in a complex, multifactorial manner, and experimental or observational approaches must take this fact into consideration. Two concepts that may be helpful in this regard are the "muscle compartment theory," by which different muscle groups, individual muscles, or muscle areas may react differently to a variety of stimuli and pathogenic factors, and the "oil well analogy," which reflects the complexity and variability of the energy resource depletion mechanisms in cells and tissues, leading to structural remodeling and functional adaptation or impairment.

The repeatability of interleukin-6, tumor necrosis factor-alpha, and C-reactive protein in COPD patients over one year

BACKGROUND

Many of the systemic manifestations of chronic obstructive pulmonary disease (COPD) are mediated through increased systemic levels of inflammatory proteins. We assessed the long term repeatability of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP) over one year and examined the relationships between these systemic markers in COPD.

METHODS

Fifty-eight stable COPD patients completed a baseline and one-year visit. Serum IL-6, plasma CRP, and plasma TNF-alpha were measured. Repeatability was expressed by intraclass correlation coefficient (R(i)) and the Bland-Altman method. Pearson correlations were used to determine the relationships between the systemic markers at both visits.

RESULTS

There was moderate repeatability with a very high degree of statistical significance (p <or= 0.001) between the two visits for all the systemic biomarkers (IL-6, CRP, and TNF-alpha). CRP was significantly associated with IL-6 at both visits (r = 0.55, p = 0.0001, r = 0.51, p = 0.0002, respectively). There were no other significant associations between the systemic markers at either of the visits.

CONCLUSIONS

Systemic inflammatory biomarkers IL-6, CRP, and TNF-alpha were moderately repeatable over a twelve month period in COPD patients. We have also shown that a robust and repeatable association between IL-6 and CRP exists.

Alveolar macrophage recruitment and activation by chronic second hand smoke exposure in mice

Approximately 15% of cases of COPD occur in non-smokers. Among the potential risk factors for COPD in non-smokers is second-hand smoke (SHS) exposure. However, the Surgeon General reported in 2006 that the evidence linking second hand smoke and COPD is insufficient to infer a causal relationship, largely because current evidence does not establish a biological link. The goal of this study was to determine whether SHS exposure can induce alveolar macrophage recruitment and expression of activation markers that we have previously demonstrated in human smokers and in mouse models of emphysema. To achieve these goals, we studied mice exposed to an ambient mixture of predominantly [89%] sidestream smoke at increasing doses over 3 months. We found that second hand smoke exposure induced a dose-dependent increase in alveolar macrophage recruitment (mean +/- sd; 224,511 +/- 52,330 vs 166,152 +/- 47,989 macrophages/ml of bronchoalveolar lavage in smoke-exposed vs air-exposed controls at 3 months, p = 0.003). We also found increased expression of several markers of alveolar macrophage activation (PLA2g7, dkfzp434l142, Trem-2, and pirin, all p < 0.01 at 3 months) and increased lavage levels of two inflammatory mediators associated with COPD (CCL2 [MCP-1], 58 +/- 12 vs. 43 +/- 22 pg/ml, p = 0.03; and TNFalpha, 138 +/- 43 vs 88 +/- 78 pg/ml, p = 0.04 at 3 months). These findings indicate that second smoke exposure can cause macrophage recruitment and activation, providing a biological link between second-hand smoke exposure and the development of inflammatory processes linked to COPD.

Exhaled nitric oxide, systemic inflammation, and the spirometric response to inhaled fluticasone propionate in severe chronic obstructive pulmonary disease: a prospective study

BACKGROUND

A subset of patients with chronic obstructive pulmonary disease (COPD) may respond more favorably to inhaled corticosteroids (ICS), but no simple method is currently utilized to predict the presence or absence of ICS responses in patients with COPD.We evaluated the ability of exhaled nitric oxide (FENO) and serum inflammatory markers (C-reactive protein [CRP], interleukin-6 [IL-6], and interleukin-8 [IL-8]) to independently predict spirometric responses to ICS in patients with COPD.

METHODS

Among 60 ex-smokers with severe COPD (mean FEV1 1.07 L, 36% of predicted), we conducted a single-arm, open-label study. Participants spent four weeks free of any ICS, followed by four weeks of ICS use (fluticasone propionate 500 mcg twice daily). FENO, CRP, IL-6, IL-8, and pre-bronchodilator spirometry were measured immediately before and after the four weeks of ICS use.

RESULTS

Baseline FENO, CRP, IL-6, and IL-8 showed no correlations to FEV1 responses to ICS. ICS responders (increase in FEV1 > or = 200 mL after four weeks of ICS) did have significantly higher baseline FENO levels compared with non-responders (46.5 parts per billion [ppb] vs. 25 ppb, p = 0.028). The receiver operating characteristic curve for FENO to discriminate responders from non-responders had an area under curve of 0.72. Baseline serum inflammatory markers did not differ between responders and non-responders.

CONCLUSION

In ex-smokers with severe COPD, a measure of local pulmonary inflammation, FENO, may be more closely associated with FEV1 responses to four weeks of ICS than are standard markers of systemic inflammation, serum CRP, IL-6, and IL-8.

Sex hormone alterations and systemic inflammation in chronic obstructive pulmonary disease

OBJECTIVE

Decreased anabolic hormone levels are described in chronic obstructive pulmonary disease (COPD), leading to important clinical consequences. The aim of this study was to evaluate the alterations in sex hormone levels in men with COPD to compare with age-matched control subjects, the determinants of these alterations, the relationship between hypogonadism and markers of systemic inflammation [interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha)] and the androgen status during an acute exacerbation of COPD.

METHODS

A total of 103 COPD patients and 30 control subjects were admitted to the study. 83 stable COPD patients and 30 control subjects were evaluated as outpatients. 20 patients with COPD exacerbation were hospitalised and evaluated before discharge and after 1 month.

RESULTS

Testosterone and dehydroepiandrosteronesulphate (DHEAS) levels of both COPD groups were lower than that of the control group. Luteinizing hormone (LH), follicle stimulating hormone (FSH) levels were increased during exacerbation. Testosterone and DHEAS levels increased and LH decreased in follow-up measurements of COPD exacerbation group. Testosterone and DHEAS levels were lower in severe COPD [forced expiratory volume in 1 s (FEV(1)) < 50%], in patients with severe hypoxaemia (PaO(2) < 60 mmHg) and in hypercapnic patients. Circulating IL-6 and TNF-alpha concentrations were higher in both stable and exacerbation phase COPD groups than controls. There was no correlation between sex hormones and TNF-alpha or IL-6.

CONCLUSION

The alterations in sex hormone levels in COPD are particularly related to FEV(1), hypoxaemia and hypercapnia. There are significant differences in hormone levels during stable and exacerbation phases of COPD; the hormonal changes are marked during exacerbation and partially regress after 1 month when the disease is stabilised.

Índice prognóstico de mortalidade BODE e atividade física em doentes pulmonares obstrutivos crônicos

INTRODUÇÃO E OBJETIVO: A DPOC é importante causa de mortalidade no mundo. Para predizer a mortalidade em pacientes com doença pulmonar obstrutiva crônica (DPOC), o índice BODE é utilizado e sua pontuação pode ser reduzida com a prática de atividade física. Este estudo objetiva verificar a associação entre o índice BODE com atividade física em indivíduos com DPOC. MÉTODOS: Foi calculado o índice BODE usando as variáveis: distância no teste da caminhada de seis minutos (TC6'); Medical Research Council Dyspnea Score (MRC); índice de massa corpórea (IMC) e grau de obstrução ao fluxo aéreo (VEF1). Os indivíduos foram divididos em grupos classificados em ativos fisicamente (AF) e inativos fisicamente (IF). O teste do qui-quadrado foi utilizado para testar a independência das variáveis. O teste t foi utilizado para comparar as variáveis TC6', MRC, IMC, VEF1 entre os grupos de indivíduos AF e IF. RESULTADOS E CONCLUSÃO: Em 38 pacientes com moderada e grave obstrução ao fluxo aéreo (36,5 ± 11,9), o valor médio do BODE foi de 4,1 ± 2,1 para o grupo de indivíduos AF; para o grupo de indivíduos IF, o valor médio do BODE foi de 6 ± 2,2. Houve diferença significativa na comparação das variáveis TC6', MRC, BODE entre os grupos. Existiu maior ocorrência de indivíduos que praticam atividade física de se situar nos quartis um e dois e os indivíduos que não praticam atividade física se situarem nos quartis três e quatro. A existência da maior pontuação do BODE para os pacientes com DPOC considerados inativos fisicamente sustenta o conceito geral de que a inatividade aumenta o risco de morte.

Relationship of BODE Index to functional tests in chronic obstructive pulmonary disease

OBJECTIVE

To determine if there is a correlation between the BODE Index and variables assessed during the Activities of Daily Living assessment, performance on lower limber tests, and peripheral muscle impairment of the upper limb in patients with chronic obstructive pulmonary disease.

MATERIALS AND METHODS

Ten men (aged 58 to 80 years old) with moderate to very severe obstruction were evaluated and classified by the BODE Index. They were evaluated by pulmonary ventilation (VE), oxygen consumption (VO2), and carbonic gas production (VCO2) on the ADL assessment; Distance Walking (DW) in the Six Minute Walking Test (6MWT) and the Six Minute Walking Test on Treadmill (6MWTT); number of repetitions in the Sit-to-Stand Test; and the Hand Grip Strength Test. Correlations were evaluated between the classification and the tests performed (Pearson and Spearman test, p<0.05).

RESULTS

The mean of the total score for the BODE Index was 2.80 (+/-1.03), with three patients scoring in the first quartile (Q1) and seven scoring in the second quartile (Q2). This Index showed a negative correlation with the 6MWTT (r=-0.86), the Sit-to-Stand Test (r=-0.66), and the Hand Grip Strength Test (r=-0.83).

CONCLUSIONS

Our results show that there is no correlation between the BODE Index and the ventilatory and metabolic responses in the Activities of Daily Living assessment. On the other hand, a correlation was observed between the BODE Index and the variables assessed in the 6MWTT, Sit-to-Stand Test, and Hand Grip Strength Test in moderate to very severe Chronic Obstructive Pulmonary Disease patients. This suggests that these tests can be employed as predictors of physical exercise capacity, perhaps as complementary tests to the BODE Index.

The effects of dietary phenolic compounds on cytokine and antioxidant production by A549 cells

Levels of inflammatory cytokines are raised in chronic obstructive pulmonary disease (COPD). A diet rich in antioxidant vitamins may protect against the development of COPD. This study examined the effects of phenolic compounds and food sources on cytokine and antioxidant production by A549 cells. The effects of the following phenolic compounds on basal and interleukin (IL)-1-stimulated release of IL-8, IL-6, and reduced glutathione (GSH) were examined: resveratrol; Bouvrage, a commercially available raspberry juice (Ella Drinks Ltd., Alloa, Clacksmannanshire, UK); and quercetin 3'-sulfate. Purification of the raspberry juice by high-performance liquid chromatography gave three fractions: Fraction 1 contained phenolic acid and vitamin C, Fraction 2 contained flavonoids and ellagic acid, and Fraction 3 contained anthocyanins and ellagitannins. IL-8 production was increased in the presence of IL-1 (165 vs. 6,011 pg/mL, P < .0001). None of the compounds tested had any significant effect on GSH. Resveratrol at concentrations > or =50 micromol/mL significantly inhibited IL-8 and IL-6 production. Similar findings were made with raspberry juice at concentrations > or =25 microL/mL, and Fractions 1 and 3 were best able to inhibit IL-8 production. Quercetin 3'-sulfate, at 25 micromol/mL, inhibited IL-8 and IL-6 production. The changes observed in IL-8 were paralleled by changes in tumor necrosis factor-alpha. Thus, phenolic compounds can significantly alter cytokine and antioxidant production.

Biomarkers of systemic inflammation in stable and exacerbation phases of COPD

Apart from the deleterious effects on the lungs, chronic obstructive pulmonary disease (COPD) should be considered a complex, systemic disease involving several organs and systems. The nature and course of systemic inflammation in COPD is important since there is a potential for anti-inflammatory therapy. The objective of the current study was to assess biomarkers of systemic inflammation in stable and exacerbation phases of COPD patients as compared to healthy controls. We also investigated the course of these biomarkers after COPD exacerbation to evaluate their usefulness for disease monitoring. Eighty-three stable patients with moderate to very severe COPD, 20 patients in exacerbation phase, and 30 subjects with normal pulmonary function were included. Serum tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and nitric oxide (NO) levels were measured once in stable COPD patients and controls and three times in the COPD exacerbation group during follow-up. TNF-alpha and IL-6 levels were higher than in controls in both stable and exacerbation groups. Although NO was not higher in the stable COPD group than in controls, it was higher in the exacerbation group. In follow-up after the exacerbation period, significant alteration was not detected in cytokine or NO levels compared to admission. Raised serum levels of TNF-alpha and IL-6 support their use as biomarkers of the systemic inflammatory response in stable COPD patients. However, the circulating biomarkers we have studied are not found to be useful either as indicators of COPD exacerbation or for monitoring recovery after exacerbation.

Inhaled and systemic corticosteroids in chronic obstructive pulmonary disease

Systemic and local inflammation is central to the pathophysiology of chronic obstructive pulmonary disease (COPD). Increased levels of inflammation have been linked to a more progressive course in COPD and have been shown to be present during an exacerbation. Decreases in inflammatory cytokines, C-reactive protein, and inflammatory cells have been observed with corticosteroid use, suggesting a possible mechanism for a therapeutic benefit of steroids. No available data support the routine use of systemic corticosteroids in stable COPD; however, short courses during exacerbations are likely to improve length of hospitalization, lung function, and relapse rate. Inhaled corticosteroids (ICS) decrease the rate of exacerbation and may improve the response to bronchodilators and decrease dyspnea in stable COPD. No study shows that ICS reduce the loss of lung function; however, recent data suggest a possible survival benefit when combined with long-acting beta agonists. There are limited data on the use of ICS in the treatment of acute exacerbations of COPD, and its role in this setting must be more clearly defined. The empiric use of systemic corticosteroids perioperatively represents another area of uncertainty. The role of pharmacogenetics in the metabolism of corticosteroids in COPD is evolving but may be partially responsible for the observed variability in patient responsiveness. The potential benefits of systemic or inhaled corticosteroid use must be weighed against the risk of known toxicities.

Metabolic and inflammatory profile in obese patients with chronic obstructive pulmonary disease

BACKGROUND

Overweight and obesity have been associated with better survival in patients with chronic obstructive pulmonary disease (COPD). On the other hand, excess body weight is associated with abnormal metabolic and inflammatory profiles that define the metabolic syndrome and predispose to cardiovascular diseases. This study was undertaken to evaluate the impact of overweight and obesity on the prevalence of the metabolic syndrome and on the metabolic and inflammatory profiles in patients with COPD.

METHODS

Twenty-eight male patients with COPD were divided into an overweight/obese group [ n = 16, body mass index (BMI) = 33.5 +/- 4.2 kg/m(2)] and normal weight group (n = 12, BMI = 21.1 +/- 2.6 kg/m(2)). Anthropometry, pulmonary function and body composition were assessed. The metabolic syndrome was diagnosed according to waist circumference, circulating levels of triglyceride and high-density lipoprotein cholesterol levels, fasting glycemia and blood pressure. C-reactive protein, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), leptin and adiponectin plasma levels were measured.

RESULTS

Airflow obstruction was less severe in overweight/obese compared with normal weight patients (forced expiratory volume(1): 51 +/- 19% versus 31 +/- 12% predicted, respectively, P < 0.01). The metabolic syndrome was diagnosed in 50% of overweight/obese patients and in none of the normal weight patients. TNF-alpha, IL-6 and leptin were significantly higher in overweight/obese patients whereas the adiponectin levels were reduced in the presence of excess weight.

CONCLUSIONS

The metabolic syndrome was frequent in overweight/obese patients with COPD. Obesity in COPD was associated with a spectrum of metabolic and inflammatory abnormalities.

Chronic obstructive pulmonary disease and body mass index in five Latin America cities: the PLATINO study

BACKGROUND

The body mass index (BMI) is a prognostic factor for chronic obstructive pulmonary disease (COPD). Despite its importance, little information is available regarding BMI alteration in COPD from a population-based study. We examined characteristics by BMI categories in the total and COPD populations in five Latin-American cities, and explored the factors influencing BMI in COPD.

METHODS

COPD was defined as a postbronchodilator forced expiratory volume in the first second/forced vital capacity (FEV(1)/FVC) <0.70. BMI was categorized as underweight (< 20 kg/m(2)), normal weight (20-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (> or = 30.0 kg/m(2)).

RESULTS

Interviews were completed in 5571 subjects from 6711 eligible individuals, and spirometry was performed in 5314 subjects. There were 759 subjects with COPD and 4555 without COPD. Compared with the non-COPD group, there was a higher proportion of COPD subjects in the underweight and normal weight categories, and a lower proportion in the obese category. Over one-half COPD subjects had BMI over 25 kg/m(2). No differences in BMI strata among countries were found in COPD subjects. Factors associated with lower BMI in males with COPD were aging, current smoking, and global initiative for chronic obstructive lung disease (GOLD) stages III-IV, whereas wheeze and residing in Santiago and Montevideo were associated with higher BMI. In females with COPD, current smoking, lower education, and GOLD stages II-IV were associated with lower BMI, while dyspnea and wheeze were associated with higher BMI.

CONCLUSIONS

BMI alterations are common in COPD with no significant differences among countries. Current smoking, age, GOLD stages, education level, residing in Santiago and Montevideo, dyspnea and wheeze were independently associated with BMI in COPD.

The value of C-reactive protein as a marker of systemic inflammation in stable chronic obstructive pulmonary disease

BACKGROUND

Systemic aspects of chronic obstructive pulmonary disease (COPD) include oxidative stress and altered circulating levels of inflammatory mediators and acute-phase proteins. C-reactive protein (CRP) reflects total systemic burden of inflammation in several disorders and has been shown to upregulate the production of proinflammatory cytokines. The aim of this study was to evaluate circulating CRP levels to determine the value of CRP as a biomarker of systemic inflammation and as an indicator of malnutrition or severity of COPD in stable COPD patients in comparison to the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6).

METHODS

Thirty-five male patients with stable COPD and 30 age- and sex-matched subjects with normal pulmonary function were admitted to the study. Serum CRP levels were measured using a commercially available kit with the turbidimetric method. Serum TNF-alpha and IL-6 concentrations were measured with ELISA kits.

RESULTS

Sixty percent of the patients had severe or very severe and 40% moderate COPD. Serum CRP was significantly higher in stable COPD patients than in control subjects (p<0.001), while TNF-alpha and IL-6 concentrations were not statistically different. Serum TNF-alpha was higher in severe or very severe COPD patients (p=0.046). When the COPD patients with a low BMI were compared to those with a normal-to-high BMI, there was a significant difference in CRP (p=0.034) and TNF-alpha (p=0.037).

CONCLUSION

The present study confirms that circulating CRP levels are higher in stable COPD patients and may thus be regarded as a valid biomarker of low-grade systemic inflammation. In addition, CRP is significantly higher in COPD patients with a low BMI and thus, together with TNF-alpha, may be considered an indicator of malnutrition in COPD patients.

IFN-γ does not mimic the catabolic effects of TNF-α

Cachexia is common in chronic inflammatory diseases and is attributed, in part, to an elevation of circulating proinflammatory cytokines. TNF-α is the prototype in this category. IFN-γ is also thought to play a role, but the evidence supporting this model is primarily indirect. To determine the direct effects of IFN-γ stimulation on muscle cells, we selected key components of the procatabolic signaling pathways by which TNF-α stimulates protein loss. We tested two hypotheses: 1) IFN-γ mimics TNF-α signaling by increasing intracellular oxidant activity and activating MAPKs and NF-κB and 2) IFN-γ increases the expression of the ubiquitin ligases atrogin1/MAFbx and muscle-specific ring finger protein 1 (MuRF1). Results showed that treatment with IFN-γ at 60 ng/ml increased Stat1 phosphorylation after 15 min, indicating receptor activation. IFN-γ had no effect on cytosolic oxidant activity, as measured by 2′,7′-dichlorofluorescein oxidation. Nor did IFN-γ activate JNK, ERK1/2, or p38 MAPK, as assessed by Western blot. Treatment for up to 60 min did not decrease IκB-α protein levels, as measured by Western blot analysis, or the DNA binding activity of NF-κB, as measured by EMSA. After 6 h, IFN-γ decreased Akt phosphorylation and increased atrogin1/MAFbx and MuRF1 mRNA. Daily treatment for up to 72 h did not alter adult fast-type myosin heavy chain content or the total protein-to-DNA ratio. These data show that responses of myotubes to IFN-γ and TNF-α differ markedly and provide little evidence for a direct catabolic effect of IFN-γ on muscle.

Chronic obstructive pulmonary disease: a chronic systemic inflammatory disease

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation in both the airways causing airway obstruction and the lung tissues causing emphysema. The disease is induced by inhalation of noxious gasses and particulate matter resulting in a chronic persistent inflammatory response in the lung, and the extent of the inflammatory reaction correlates with the severity of the disease. This chronic inflammatory response in the lung is also associated with a significant systemic inflammatory response with downstream adverse clinical health effects. The systemic response in COPD is associated with mortality, specifically cardiovascular mortality. This review describes the nature of the systemic inflammatory response in COPD and the clinical manifestations associated with the systemic response, with a focus on the potential mechanisms for these adverse health effects.

Inverse association of plasma IL-13 and inflammatory chemokines with lung function impairment in stable COPD: a cross-sectional cohort study

Background

Chronic obstructive pulmonary disease (COPD) is a heterogeneous syndrome characterized by varying degrees of airflow limitation and diffusion impairment. There is increasing evidence to suggest that COPD is also characterized by systemic inflammation. The primary goal of this study was to identify soluble proteins in plasma that associate with the severity of airflow limitation in a COPD cohort with stable disease. A secondary goal was to assess whether unique markers associate with diffusion impairment, based on diffusion capacity of carbon monoxide (DLCO), independent of the forced expiratory volume in 1 second (FEV₁).

Methods

A cross sectional study of 73 COPD subjects was performed in order to examine the association of 25 different plasma proteins with the severity of lung function impairment, as defined by the baseline measurements of the % predicted FEV₁ and the % predicted DLCO. Plasma protein concentrations were assayed using multiplexed immunobead-based cytokine profiling. Associations between lung function and protein concentrations were adjusted for age, gender, pack years smoking history, current smoking, inhaled corticosteroid use, systemic corticosteroid use and statin use.

Results

Plasma concentrations of CCL2/monocyte chemoattractant protein-1 (CCL2/MCP-1), CCL4/macrophage inflammatory protein-1β (CCL4/MIP -1β), CCL11/eotaxin, and interleukin-13 (IL-13) were inversely associated with the % FEV₁. Plasma concentrations of soluble Fas were associated with the % DLCO, whereas CXCL9/monokine induced by interferon-γ (CXCL9/Mig), granulocyte- colony stimulating factor (G-CSF) and IL-13 showed inverse relationships with the % DLCO.

Conclusion

Systemic inflammation in a COPD cohort is characterized by cytokines implicated in inflammatory cell recruitment and airway remodeling. Plasma concentrations of IL-13 and chemoattractants for monocytes, T lymphocytes, and eosinophils show associations with increasing severity of disease. Soluble Fas, G-CSF and CXCL9/Mig may be unique markers that associate with disease characterized by disproportionate abnormalities in DLCO independent of the FEV₁.