Hemoglobin, erythropoietin and systemic inflammation in exacerbations of chronic obstructive pulmonary disease

Influence of TMPRSS6 genotype on iron status parameters in stable COPD patients

Background

The SNP rs855791 has been linked to increased hepcidin levels, variations in serum iron, transferrin saturation and red blood cell indices. Our goal was to determine the prevalence of this polymorphism among COPD patients and to assess its impact on iron status parameters in patients with stable COPD.

Methods

We analysed iron status parameters and genetic data from 29 COPD patients with wild-type genotype (WT group) and 65 COPD patients with either homozygous or heterozygous genotype (HH group). Additionally, the prevalence of SNP rs855791 was assessed in 192 volunteers.

Results

The frequency distribution of SNP rs855791 was comparable between the COPD patients and control subjects (p=0.791). Iron status parameters were within their respective reference values and showed neither statistically nor clinically significant difference between the WT and HH group of COPD patients. However, after excluding patients with (sub)clinical vitamin B12 deficiency and/or hypoxemia, WT group of patients exhibited significantly lower erythropoietin levels (p=0.015). The area under the curve for erythropoietin was 0.688 (95% CI: 0.545-0.830, p=0.015), with an optimal cut-off of 9.74, sensitivity of 61.2% (95% CI: 58.1-64.3) and specificity of 65.0% (95% CI: 61.8-68.3).

Conclusions

Iron status parameters do not differ between WT and HH groups of stable COPD patients. Statistical but not clinical difference in EPO levels was observed in a subgroup of patients. In addition to promoting erythropoiesis, EPO may regulate hepcidin levels and thus influence the development of iron deficiency and/or anaemia. Also, EPO's direct effect on immune cells and down-regulation of inflammatory reactions should be considered in this context.

Red cell distribution width-to-albumin ratio is a predictor of survival in hepatitis B virus-associated decompensated cirrhosis

OBJECTIVE

The aim of this study was to ascertain whether red cell distribution width-to-albumin ratio (RAR) is associated with survival in hepatitis B virus (HBV)-associated decompensated cirrhosis (DC) patients.

METHODS

A cohort of 167 patients with confirmed HBV-DC was enrolled in our study. Demographic characteristics and laboratory data were obtained. The main endpoint was mortality at 30 days. The receiver operating characteristic curve and multivariable regression analysis were used to assess the power of RAR for predicting prognosis.

RESULTS

Mortality at 30 days was 11.4% (19/167). The RAR levels were higher in the nonsurvivors than the survivors, and elevated RAR levels were clearly associated with poor prognosis. Moreover, the predictive powers of RAR and Model for End-Stage Liver Disease score were not obviously different.

CONCLUSION

Our data indicate that RAR is a novel potential prognostic biomarker of mortality in HBV-DC.

Association Between Circulating Zinc and Risk for Childhood Asthma and Wheezing: A Meta-analysis on 21 Articles and 2205 Children

Asthma is one of the most frequent chronic diseases in children, and growing focus is placed on the exploration of attributable risk factors. Currently, no consensus has been reached on the implication of circulating zinc in the development of asthma. We aimed to conduct a meta-analysis to examine the association between circulating zinc and risk for childhood asthma and wheezing. We searched PubMed, Web of Science, EMBASE, and Google Scholar from inception until December 1, 2022. All procedures were performed independently and in duplicate. Random-effects model was adopted to derive standardized mean difference (SMD) and 95% confidence interval (95% CI). Statistical analyses were completed using the STATA software. Twenty-one articles and 2205 children were meta-analyzed. Overall, there was a statistically significant association between circulating zinc and risk for childhood asthma and wheezing (SMD: -0.38; 95% CI: -0.60 to -0.17; I2=82.6%, p<0.001), without evidence of publication bias as revealed by Begg's (p=0.608) and Egger (p=0.408) tests. Subgroup analyses showed that children with asthma or wheezing in Middle Eastern countries had significantly lower circulating zinc levels than controls (SMD: -0.42; 95% CI: -0.69 to -0.14; p<0.001; I2=87.1%). Additionally, average circulating zinc levels in asthma children were 0.41 μg/dl lower than that in controls, and the difference was statistically significant (SMD: -0.41; 95% CI: -0.65 to -0.16; p<0.001; I2=83.7%). By contrast, children with wheezing were 0.20 μg/dl lower than that in controls, and no between-group difference was noted (SMD=-0.20; 95% CI: -0.58 to 0.17; p=0.072; I2=69.1%). Our findings indicated that circulating zinc was associated with a significant risk for childhood asthma and its related symptom wheezing.

Differential Diagnosis of Suspected Chronic Obstructive Pulmonary Disease Exacerbations in the Acute Care Setting: Best Practice

Patients with chronic obstructive pulmonary disease (COPD) may suffer from acute episodes of worsening dyspnea, often associated with increased cough, sputum, and/or sputum purulence. These exacerbations of COPD (ECOPDs) impact health status, accelerate lung function decline, and increase the risk of hospitalization. Importantly, close to 20% of patients are readmitted within 30 days after hospital discharge, with great cost to the person and society. Approximately 25% and 65% of patients hospitalized for an ECOPD die within 1 and 5 years, respectively. Patients with COPD are usually older and frequently have concomitant chronic diseases, including heart failure, coronary artery disease, arrhythmias, interstitial lung diseases, bronchiectasis, asthma, anxiety, and depression, and are also at increased risk of developing pneumonia, pulmonary embolism, and pneumothorax. All of these morbidities not only increase the risk of subsequent ECOPDs but can also mimic or aggravate them. Importantly, close to 70% of readmissions after an ECOPD hospitalization result from decompensation of other morbidities. These observations suggest that in patients with COPD with worsening dyspnea but without the other classic characteristics of ECOPD, a careful search for these morbidities can help detect them and allow appropriate treatment. For most morbidities, a thorough clinical evaluation supplemented by appropriate clinical investigations can guide the healthcare provider to make a precise diagnosis. This perspective integrates the currently dispersed information available and provides a practical approach to patients with COPD complaining of worsening respiratory symptoms, particularly dyspnea. A systematic approach should help improve outcomes and the personal and societal cost of ECOPDs.

Increased Risk of Anemia in Patients with Asthma

Purpose

Asthma can cause a systemic inflammatory response, and anemia of chronic disease (ACD) is known to be caused by other disorders with a chronic inflammatory state. However, it is unclear whether the incidence of anemia is increased in patients with asthma. The objective of this study was to compare the incidence of anemia in patients with asthma and healthy adults.

Patients and Methods

This retrospective cohort study included patients newly diagnosed with asthma at Seoul National University Hospital from 2010 to 2017. Patients with comorbidities before the first visit (index date) that may increase anemia risk were excluded. Cox regression models adjusting for patient age, sex, and obesity were used to compare anemia hazard ratios (HRs) between asthma patients (n=1354) and healthy adults (n=1731).

Results

This study included 3085 patients. During 5-y follow-up, anemia occurred in 203 (15.0%) patients with asthma and 79 (4.6%) healthy adults. Compared with healthy adults, the HR for anemia after adjusting for age, sex, and obesity was 4.06 (95% CI: 2.70-6.09) in patients with asthma. In patients aged 18-64.9 y, the adjusted HR of anemia was 3.27 (95% CI: 2.12-5.04) in patients with asthma, compared to healthy patients. In patients >65 y, this adjusted HR was 5.56 (95% CI: 1.31-23.67).

Conclusion

The risk of anemia was increased in patients with asthma after adjusting for sex, age, and obesity and excluding comorbidities that can cause anemia. These results suggest the need for regular monitoring for anemia in patients with asthma.

The role of iron in chronic inflammatory diseases: from mechanisms to treatment options in anemia of inflammation

Anemia of inflammation (AI) is a highly prevalent comorbidity in patients affected by chronic inflammatory disorders, such as chronic kidney disease, inflammatory bowel disease, or cancer, that negatively affect disease outcome and quality of life. The pathophysiology of AI is multifactorial, with inflammatory hypoferremia and iron-restricted erythropoiesis playing a major role in the context of disease-specific factors. Here, we review the recent progress in our understanding of the molecular mechanisms contributing to iron dysregulation in AI, the impact of hypoferremia and anemia on the course of the underlying disease, and (novel) therapeutic strategies applied to treat AI.

Anemia in chronic obstructive pulmonary disease: A systematic review

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease that is characterized by poor airflow and airway inflammation. It is estimated that the global prevalence of COPD is about 13.1%. Anemia is associated with increased morbidity and hospitalization duration. In this systematic review, we investigate the association between all types of anemia and COPD progression.

METHODS

We systematically searched electronic databases, including Scopus, Medline/PubMed, EMBASE, Web of Sciences (WOS), and Cochrane Library, using the following mesh-standardized keywords: (((anemia∗ OR anaemia∗) OR "chronic anemia disease" [Mesh] OR "CAD" OR "iron deficiency anemia" OR" IDA" OR) AND ("COPD" [Mesh] OR "chronic obstructive pulmonary disease")) until February 2022.

RESULTS

Overall of 11,158 studies were included. Ultimately, 59 studies were included in the analysis. The most apparent findings from the analysis were that exacerbation of COPD, increased hospitalization, and increased long-term mortality were associated with anemia. Further analysis showed that iron deficiency (ID) is a common finding in COPD and is accompanied by an increase in the systolic pulmonary artery pressure.

CONCLUSION

Despite the comfortable control of anemia, the absence of treatment can be life-threatening in patients with COPD. Our systematic results showed significant homogeneity between studies on the increased mortality rate in anemic COPD, increased hospitalization, and decreased quality of life.

Red Blood Cell Distribution Width (RDW) as a Predictor of In-Hospital Mortality in COVID-19 Patients; a Cross Sectional Study

INTRODUCTION

Red blood cell distribution width (RDW) has been introduced as a predictive factor for mortality in several critical illnesses and infectious diseases. This study aimed to assess the possible relationship between RDW on admission and COVID-19 in-hospital mortality.

METHOD

This cross-sectional study was performed using the Isfahan COVID-19 registry. Adult confirmed cases of COVID-19 admitted to four hospitals affiliated with Isfahan University of Medical Sciences in Iran were included. Age, sex, O2 saturation, RDW on admission, Intensive Care Unit admission, laboratory data, history of comorbidities, and hospital outcome were extracted from the registry. Cox proportional hazard regression was used to study the independent association of RDW with mortality.

RESULTS

4152 patients with the mean age of 61.1 ± 16.97 years were included (56.2% male). 597 (14.4%) cases were admitted to intensive care unit (ICU) and 477 (11.5%) cases died. The mortality rate of patients with normal and elevated RDW was 7.8% and 21.2%, respectively (OR= 3.1, 95%CI: 2.6-3.8), which remained statistically significant after adjusting for age, O2 saturation, comorbidities, and ICU admission (2.03, 95% CI: 1.68-2.44). Moreover, elevated RDW mortality Hazard Ratio in patients who were not admitted to ICU was higher than ICU-admitted patients (3.10, 95% CI: 2.35-4.09 vs. 1.47, 95% CI: 1.15-1.88, respectively).

CONCLUSION

The results support the presence of an association between elevated RDW and mortality in patients with COVID-19, especially those who were not admitted to ICU. It seems that elevated RDW can be used as a predictor of mortality in COVID-19 cases.

Association between red blood cell distribution width and long-term mortality in acute respiratory failure patients

The red cell distribution width (RDW) has been reported to be positively correlated with short-term mortality of pulmonary disease in adults. However, it is not clear whether RDW was associated with the long-term prognosis for acute respiratory failure (ARF). Thus, an analysis was conducted to evaluate the association between RDW and 3-year mortality of patients by the Cox regression analysis, generalized additives models, subgroup analysis and Kaplan–Meier analysis. A total of 2999 patients who were first admitted to hospital with ARF were extracted from the Medical Information Mart for Intensive Care III database (MIMIC-III). The Cox regression analysis showed that the high RDW was associated with 3-year mortality (HR 1.10, 95% CI 1.07, 1.12, P < 0.0001) after adjusting for age, gender, ethnicity and even co-morbid conditions. The ROC curve illustrated the AUC of RDW was 0.651 (95% CI 0.631, 0.670) for prediction of 3-year mortality. Therefore, there is an association between the RDW and survival time of 3 years follow-up, particularly a high RDW on admission was associated with an increased risk of long-term mortality in patients with ARF. RDW may provide an alternative indicator to predict the prognosis and disease progression and more it is easy to get.

Effects of anemia on the survival of patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

OBJECTIVES

Anemia is often seen in chronic obstructive pulmonary disease (COPD) patients. However, the implications of anemia on the outcomes of patients with COPD is not clearly known. Therefore, we conducted a systematic review and meta-analysis to evaluate the effects of anemia on the morbidity and mortality of patients with COPD.

METHODS

We followed PRISMA guidelines to perform a systematic identification of relevant publications in the literature on four academic databases: MEDLINE, Scopus, EMBASE, and CENTRAL.

RESULTS

Out of 1845 records, we included data from 15 articles including 420 970 participants in this review. Our systematic review presents a 2b level of evidence suggesting a higher duration of hospital stay, Charlson comorbidity index score, and mortality rate for patients with COPD and anemia than for patients with COPD without anemia. The meta-analysis revealed a moderate effect increase in the mean duration of hospital stay (Hedge's g, 0.55), Charlson comorbidity index (0.68), and mortality rate (0.49) in patients with COPD and anemia as compared to those in patients with COPD without anemia.

CONCLUSION

The current systematic review and meta-analysis provide evidence regarding the detrimental consequences of anemia on the morbidity and mortality of patients with COPD.

Iron and Sphingolipids as Common Players of (Mal)Adaptation to Hypoxia in Pulmonary Diseases

Hypoxia, or lack of oxygen, can occur in both physiological (high altitude) and pathological conditions (respiratory diseases). In this narrative review, we introduce high altitude pulmonary edema (HAPE), acute respiratory distress syndrome (ARDS), Chronic Obstructive Pulmonary Disease (COPD), and Cystic Fibrosis (CF) as examples of maladaptation to hypoxia, and highlight some of the potential mechanisms influencing the prognosis of the affected patients. Among the specific pathways modulated in response to hypoxia, iron metabolism has been widely explored in recent years. Recent evidence emphasizes hepcidin as highly involved in the compensatory response to hypoxia in healthy subjects. A less investigated field in the adaptation to hypoxia is the sphingolipid (SPL) metabolism, especially through Ceramide and sphingosine 1 phosphate. Both individually and in concert, iron and SPL are active players of the (mal)adaptation to physiological hypoxia, which can result in the pathological HAPE. Our aim is to identify some pathways and/or markers involved in the physiological adaptation to low atmospheric pressures (high altitudes) that could be involved in pathological adaptation to hypoxia as it occurs in pulmonary inflammatory diseases. Hepcidin, Cer, S1P, and their interplay in hypoxia are raising growing interest both as prognostic factors and therapeutical targets.

Anaemia and iron dysregulation: untapped therapeutic targets in chronic lung disease?

Hypoxia is common in many chronic lung diseases. Beyond pulmonary considerations, delivery of oxygen (O2) to the tissues and subsequent O2 utilisation is also determined by other factors including red blood cell mass and iron status; consequently, disruption to these mechanisms provides further physiological strains on an already stressed system. O2 availability influences ventilation, regulates pulmonary blood flow and impacts gene expression throughout the body. Deleterious effects of poor tissue oxygenation include decreased exercise tolerance, increased cardiac strain and pulmonary hypertension in addition to pathophysiological involvement of multiple other organs resulting in progressive frailty. Increasing inspired O2 is expensive, disliked by patients and does not normalise tissue oxygenation; thus, other strategies that improve O2 delivery and utilisation may provide novel therapeutic opportunities in patients with lung disease. In this review, we focus on the rationale and possibilities for doing this by increasing haemoglobin availability or improving iron regulation.

Clinical characteristics of pulmonary hypertension patients living in plain and high-altitude regions

OBJECTIVE

The demographic characteristics, ratio of aetiologies and biochemical parameters of adult patients with pulmonary hypertension (PH) living in plain and high-altitude regions were investigated and analysed.

METHODS

In total, 2846 adult patients with PH hospitalized from 2010 to 2015 in the Second Xiangya Hospital of Central South University and Qinghai Red Cross Hospital were retrospectively investigated.

RESULTS

(1) In the present study, the numbers of patients with PH in both the plain and high-altitude regions increased annually (P < 0.05), and the in-hospital prevalence of PH significantly increased over time in the high-altitude region. PH was more common in women in the plain region. Furthermore, compared with PH patients living in the plain region, those living in the high-altitude region were older (P < 0.05) and had higher smoking rates (P < 0.05). In the plain region, the greatest proportion of patients with PH belonged to group 2 (PH because of left heart disease), while in the high-altitude region, group 3 (PH because of lung diseases and/or hypoxia) was the most common (P < 0.05). (2) Haemoglobin levels, red blood cell counts, mean platelet volumes and platelet volume distribution widths were lower in PH patients living in the plain region than in those living in the high-altitude region. Furthermore, platelet counts were higher in patients living in the plain region than in those living in the high-altitude region (P < 0.05). The BNP/NT-proBNP levels were higher in PH patients living in the plain region (45.5%), which were mostly in group 4, than in those living the high-altitude region (P < 0.05).

CONCLUSIONS

The data from the hospitals in both the plain and high-altitude regions show a tendency towards increased in-hospital prevalence of PH over the last 6 years. The most common aetiologies of PH in patients living in the plain region and high-altitude regions were left heart disease and lung disease, respectively. Compared with PH patients living in the plain region, those living in the high-altitude region had better cardiac function and less severe PH.

Effectiveness of early rehabilitation on patients with chronic obstructive lung disease and acute respiratory failure in intensive care units: A case-control study

The effect of early rehabilitation on the outcome of patients with chronic obstructive pulmonary disease (COPD) and acute respiratory failure (ARF) in intensive care units (ICUs) remains unclear. We examined the effect of early rehabilitation on the outcomes of COPD patients requiring mechanical ventilation (MV) in the ICU. This retrospective, observational, case–control study was conducted in a medical center with a 19-bed ICU. The records of all 105 ICU patients with COPD and ARF who required MV from January to December 2011 were examined. The outcomes (MV duration, rates of successful weaning and survival, lengths of ICU and hospital stays, and medical costs) were recorded and analyzed. During the study period, 35 patients with COPD underwent early rehabilitation in the ICU and 70 demographically and clinically matched patients with similar COPD stage, cause of intubation, type of respiratory failure, and levels of disease severity who had not undergone early rehabilitation in the ICU were selected as comparative controls. Multiple regression analysis showed that early rehabilitation was significantly negatively associated with MV duration. Early rehabilitation for COPD patients in the ICU with ARF shortened the duration of their MV.

The influence of anemia on one-year exacerbation rate of patients with COPD-PH

BACKGROUND

Anemia is prevalent not only in COPD but also in pulmonary hypertension. We postulated that anemia may have certain prognostic value in COPD concomitant with PH due to COPD (COPD-PH).

METHODS

We performed a 12-month prospective investigation to follow up COPD patients with or without PH assessed by right heart catheterization. Eligible patients were enrolled, stratified into COPD-PH-anemia group (n = 40), COPD-PH group (n = 42), COPD-anemia group (n = 48), and COPD group(n = 50), and then followed up for 12 months.

RESULTS

After the follow-up, for both of the actual variation value and variation rate, the increase of NT-pro BNP (P<0.001; P = 0.03) and CAT score (P = 0.001; 0.002), as well as the decrease of PaO₂ (P = 0.03; 0.086) and Peak VO₂ (P = 0.021; 0.009) in COPD-PH-anemia group were highest among four groups. The cumulative one-year survival rates were similar among four groups (P = 0.434). The cumulative exacerbation-free rate was lowest in COPD-PH-anemia group among four groups (P<0.001). Hemoglobin was an independent promoting factor for the probability of hospitalization due to exacerbation ≧ 1/year in patients with COPD-PH-anemia [HR 3.121(2.325-5.981); P<0.001].

CONCLUSIONS

Anemia is a promoting factor for the worsening of exercise capacity, deterioration of hypoxemia, declining of life quality, and aggravation of exacerbations in patients with COPD-PH-anemia, by contrast with COPD-PH, COPD-anemia, and COPD.

Relationships of Serum Iron Parameters and Hemoglobin with Forced Expiratory Volume in 1 Second in Patients with Chronic Obstructive Pulmonary Disease

Background

Although chronic obstructive pulmonary disease is a known cause of secondary polycythemia with elevated erythropoietic demands in response to hypoxemia, anemia is relatively common in patients with chronic obstructive pulmonary disease and is related to increased mortality. However, little is currently known about the relationship between various iron parameters and disease severity in chronic obstructive pulmonary disease patients.

Methods

Data from the fifth Korean National Health and Nutrition Examination Survey, a population-based epidemiologic survey conducted in 2010–2012, were used. A total of 1,129 patients with chronic obstructive pulmonary disease were examined to reveal the associations between the forced expiratory volume in 1 second (FEV1) and hemoglobin and iron parameters, including serum iron, ferritin, total iron binding capacity, and transferrin saturation, using Spearman correlations and multiple linear regression analyses.

Results

The FEV1 was positively correlated with serum hemoglobin (γ=0.37, P<0.001), iron (γ=0.20, P<0.001), transferrin saturation (γ=0.19, P<0.001), and ferritin (γ=0.22, P<0.001), and negatively correlated with age (γ=−0.40, P<0.001) and lower in female patients (γ=−0.56, P<0.001) in the Spearman correlation. The FEV1 was independently associated with serum iron (β=0.049, P=0.035) and transferrin saturation (β=0.049, P=0.035) after adjusting for age, sex, and body mass index in the multiple linear regression analyses.

Conclusion

The serum iron and transferrin saturation levels were independently associated with FEV1 as a marker of chronic obstructive pulmonary disease severity.

Anemia, hypoalbuminemia, and elevated troponin levels as risk factors for respiratory failure in patients with severe exacerbations of chronic obstructive pulmonary disease requiring invasive mechanical ventilation

Aim

To determine in-hospital and post-discharge mortality, readmission rates, and predictors of invasive mechanical ventilation (IMV) in patients treated at intensive care unit (ICU) due to acute exacerbations of chronic obstructive pulmonary disease (AECOPD).

Methods

A retrospective observational cohort study included all patients treated at a respiratory ICU for AECOPD during one year. A total of 62 patients (41 men) with mean age 68.4 ± 10.4 years were analyzed for outcomes including in-hospital and post-discharge mortality, readmission rates, and IMV. Patients’ demographic, hematologic, biochemical data and arterial blood gas (ABG) values were recorded on admission to hospital. Mean duration of follow-up time was 2.4 years.

Results

Of 62 patients, 7 (11.3%) died during incident hospitalization and 21 (33.9%) died during the follow-up. The overall 2.4-year mortality was 45.2%. Twenty nine (46.8%) patients were readmitted due to AECOPD. The average number of readmissions was 1.2. Multivariate analysis showed that blood pH, bicarbonate levels, low albumin, low serum chloride, and low hemoglobin were significant predictors of IMV during incident hospitalization (P < 0.001 for the overall model fit).

Conclusion

High in-hospital and post-discharge mortality and high readmission rates in our patients treated due to AECOPD at ICU indicate that these patients represent a high risk group in need of close monitoring. Our results suggested that anemia, hypoalbuminemia, and elevated troponin levels were risk factors for the need of IMV in severe AECOPD. Identification of such high-risk patients could provide the opportunity for administration of an appropriate and timely treatment.

Erythropoietin levels in patients with sleep apnea: a meta-analysis

Currently available data regarding the blood levels of erythropoietin (EPO) in sleep apnea (SA) patients are contradictory. The aim of the present meta-analysis was to evaluate the EPO levels in SA patients via quantitative analysis. A systematic search of Pubmed, Embase, and Web of Science were performed. EPO levels in SA group and control group were extracted from each eligible study. Weight mean difference (WMD) or Standard mean difference (SMD) with 95% confidence interval (CI) was calculated by using fixed-effects or random effect model analysis according to the degree of heterogeneity between studies. A total of 9 studies involving 407 participants were enrolled. The results indicated that EPO levels in SA group were significantly higher than that in control group (SMD 0.61, 95% CI 0.11–1.11, p = 0.016). Significantly higher EPO levels were found in patients with body mass index <30 kg/m², and cardiovascular complications in the subsequent subgroup analysis (both p < 0.05). High blood EPO levels were found in SA patients in the present meta-analysis.

The impact of anaemia and iron deficiency in chronic obstructive pulmonary disease: A clinical overview

INTRODUCTION

Anaemia is increasingly recognised as an important comorbidity in the context of chronic obstructive pulmonary disease (COPD), but remains undervalued in clinical practice. This review aims to characterise the impact of anaemia and iron deficiency in COPD.

METHODS

Literature review of studies exploring the relationship between anaemia/iron deficiency and COPD, based on targeted MEDLINE and Google Scholar queries.

RESULTS

The reported prevalence of anaemia in COPD patients, ranging from 4.9% to 38.0%, has been highly variable, due to different characteristics of study populations and lack of a consensus on the definition of anaemia. Inflammatory processes seem to play an important role in the development of anaemia, but other causes (including nutritional deficiencies) should not be excluded from consideration. Anaemia in COPD has been associated with increased morbidity, mortality, and overall reduced quality of life. The impact of iron deficiency, irrespective of anaemia, is not as well studied, but it might have important implications, since it impacts production of red blood cells and respiratory enzymes. Treatment of anaemia/iron deficiency in COPD remains poorly studied, but it appears reasonable to assume that COPD patients should at least receive the same type of treatment as other patients.

CONCLUSIONS

Anaemia and iron deficiency continue to be undervalued in most COPD clinical settings, despite affecting up to one-third of patients and having negative impact on prognosis. Special efforts should be made to improve clinical management of anaemia and iron deficiency in COPD patients as a means of achieving better patient care.

Impact of anemia on short-term survival in severe COPD exacerbations: a cohort study

PURPOSE

Anemia is reported to be an independent predictor of hospitalizations and survival in COPD. However, little is known of its impact on short-term survival during severe COPD exacerbations. The primary objective of this study was to determine whether the presence of anemia increases the risk of death in acute respiratory failure due to severe COPD exacerbations.

PATIENTS AND METHODS

Consecutive patients with COPD exacerbation who were admitted to the intensive care unit with the diagnosis of acute respiratory failure and required either invasive or noninvasive ventilation (NIV) were analyzed.

RESULTS

A total of 106 patients (78.3% male; median age 71 years) were included in the study; of them 22 (20.8%) needed invasive ventilation immediately and 84 (79.2%) were treated with NIV. NIV failure was observed in 38 patients. Anemia was present in 50% of patients, and 39 patients (36.8%) died during hospital stay. When compared to nonanemic patients, hospital mortality was significantly higher in the anemic group (20.8% vs 52.8%, respectively; P=0.001). Stepwise multivariate logistic regression analysis showed that presence of anemia and NIV failure were independent predictors of hospital mortality with odds ratios (95% confidence interval) of 3.99 ([1.39-11.40]; P=0.010) and 2.56 ([1.60-4.09]; P<0.001), respectively. Anemia was not associated with long-term survival in this cohort.

CONCLUSION

Anemia may be a risk factor for hospital death in severe COPD exacerbations requiring mechanical ventilatory support.

A Systematic Review of Diagnostic Biomarkers of COPD Exacerbation

The aims of this systematic review were to determine which blood-based molecules have been evaluated as possible biomarkers to diagnose chronic obstructive pulmonary disease (COPD) exacerbations (AECOPD) and to ascertain the quality of these biomarker publications. Patients of interest were those that have been diagnosed with COPD. MEDLINE, EMBASE, and CINAHL databases were searched systematically through February 2015 for publications relating to AECOPD diagnostic biomarkers. We used a modified guideline for the REporting of tumor MARKer Studies (mREMARK) to assess study quality. Additional components of quality included the reporting of findings in a replication cohort and the use of receiver-operating characteristics area-under-the curve statistics in evaluating performance. 59 studies were included, in which the most studied biomarkers were C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). CRP showed consistent elevations in AECOPD compared to control subjects, while IL-6 and TNF-α had variable statistical significance and results. mREMARK scores ranged from 6 to 18 (median score of 13). 12 articles reported ROC analyses and only one study employed a replication cohort to confirm biomarker performance. Studies of AECOPD diagnostic biomarkers remain inconsistent in their reporting, with few studies employing ROC analyses and even fewer demonstrating replication in independent cohorts.

Erythropoietin Pathway: A Potential Target for the Treatment of Depression

During the past decade, accumulating evidence from both clinical and experimental studies has indicated that erythropoietin may have antidepressant effects. In addition to the kidney and liver, many organs have been identified as secretory tissues for erythropoietin, including the brain. Its receptor is expressed in cerebral and spinal cord neurons, the hypothalamus, hippocampus, neocortex, dorsal root ganglia, nerve axons, and Schwann cells. These findings may highlight new functions for erythropoietin, which was originally considered to play a crucial role in the progress of erythroid differentiation. Erythropoietin and its receptor signaling through JAK2 activate multiple downstream signaling pathways including STAT5, PI3K/Akt, NF-κB, and MAPK. These factors may play an important role in inflammation and neuroprogression in the nervous system. This is particularly true for the hippocampus, which is possibly related to learning, memory, neurocognitive deficits and mood alterations. Thus, the influence of erythropoietin on the downstream pathways known to be involved in the treatment of depression makes the erythropoietin-related pathway an attractive target for the development of new therapeutic approaches. Focusing on erythropoietin may help us understand the pathogenic mechanisms of depression and the molecular basis of its treatment.

Systematic review of anaemia and inflammatory markers in chronic obstructive pulmonary disease

This systematic review synthesizes the relevant published articles on the prevalence of anaemia in patients with chronic obstructive pulmonary disease (COPD) and its relationship with inflammatory markers. The upregulation of erythropoietin in anaemia maintains homeostasis. However, anaemic COPD patients do not respond to increased levels of erythropoietin. The increased levels could be an indicator of the peripheral erythropoietin resistance in COPD. Anaemia and inflammation are associated with an increased risk of hospitalization and mortality in these patients. The understanding of anaemia in chronic inflammation is that anaemia is at least partially due to the excessive production of inflammatory cytokines, which can contribute to improvements in the management, prognosis, and survival of patients with COPD and anaemia.

Anemia in Chronic Obstructive Pulmonary Disease and the Potential Role of Iron Deficiency

The purpose of this review is to evaluate the role of anemia on patient outcomes in chronic obstructive pulmonary disease (COPD), the potential contribution that low iron stores may play in this process, and possible treatment considerations. A review of research studies found that anemia is associated with declining functional outcomes, increased health care utilization and costs, and increased mortality in COPD. Associations exist between reduced iron intake and progression of COPD and in reduction of iron status with declining lung function. Currently data are limited on the effects of either treating anemia or utilizing iron supplementation in anemic COPD patients. If iron supplementation might therefore reverse some of the declines that patients experience, then routine screening and treatment may turn out to be an effective, simple and inexpensive intervention. Iron supplementation models utilized in other inflammatory-related disease states were reviewed as a possible starting point to evaluate treatment options in COPD. Future research can be directed to establish best practice standards for the use of iron supplementation in COPD.

Anemia in Chronic obstructive pulmonary disease: Prevalence, pathogenesis, and potential impact

Chronic obstructive pulmonary disease (COPD) is a common preventable and treatable lifestyle-related disease with high global prevalence. COPD is associated with significant morbidity and mortality worldwide. Comorbidities are important events in the natural history of the disease and have a negative effect on the morbidity and mortality of COPD patients. Cardiac diseases, lung cancer, osteoporosis, and depression are common comorbidities reported for COPD. Recently, anemia has been recognized as a frequent comorbidity in COPD patients. The prevalence of anemia in patients with COPD varies from 7.5% to 33%. Anemia of chronic disease (ACD) is probably the most common type of anemia associated with COPD. ACD is driven by COPD-mediated systemic inflammation. Anemia in COPD is associated with greater healthcare resource utilization, impaired quality of life, decreased survival, and a greater likelihood of hospitalization. We need large prospective studies to discern the association between anemia and COPD.

Anaemia in chronic obstructive pulmonary disease: an insight into its prevalence and pathophysiology

Chronic obstructive pulmonary disease (COPD) is a major health problem, with increasing morbidity and mortality. There is a growing literature regarding the extra-pulmonary manifestations of COPD, which can have a significant impact on symptom burden and disease progression. Anaemia is one of the more recently identified co-morbidities, with a prevalence that varies between 4.9% and 38% depending on patient characteristics and the diagnostic criteria used. Systemic inflammation seems to be an important factor for its establishment and repeated bursts of inflammatory mediators during COPD exacerbations could further inhibit erythropoiesis. However, renal impairment, malnutrition, low testosterone levels, growth hormone level abnormalities, oxygen supplementation, theophylline treatment, inhibition of angiotensin-converting enzyme and aging itself are additional factors that could be associated with the development of anaemia. The present review evaluates the published literature on the prevalence and significance of anaemia in COPD. Moreover, it attempts to elucidate the reasons for the high variability reported and investigates the complex pathophysiology underlying the development of anaemia in these patients.

Anemia and iron deficiency in COPD patients: prevalence and the effects of correction of the anemia with erythropoiesis stimulating agents and intravenous iron

BACKGROUND

Little is known about iron deficiency (ID) and anemia in Chronic Obstructive Pulmonary Disease (COPD). The purposes of this study were: (i) To study the prevalence and treatment of anemia and ID in patients hospitalized with an exacerbation of COPD. (ii) to study the hematological responses and degree of dyspnea before and after correction of anemia with subcutaneous Erythropoiesis Stimulating Agents (ESAs) and intravenous (IV) iron therapy, in ambulatory anemic patients with both COPD and chronic kidney disease.

METHODS

(i) We examined the hospital records of all patients with an acute exacerbation of COPD (AECOPD) to assess the investigation, prevalence, and treatment of anemia and ID. (ii) We treated 12 anemic COPD outpatients with the combination of ESAs and IV-iron, given once weekly for 5 weeks. One week later we measured the hematological response and the severity of dyspnea by Visual Analogue Scale (VAS).

RESULTS

(i) Anemia and iron deficiency in hospitalized COPD patients: Of 107 consecutive patients hospitalized with an AECOPD, 47 (43.9%) were found to be anemic on admission. Two (3.3%) of the 60 non-anemic patients and 18 (38.3%) of the 47 anemic patients had serum iron, percent transferrin saturation (%Tsat) and serum ferritin measured. All 18 (100%) anemic patients had ID, yet none had oral or IV iron subscribed before or during hospitalization, or at discharge. (ii) Intervention outpatient study: ID was found in 11 (91.7%) of the 12 anemic ambulatory patients. Hemoglobin (Hb), Hematocrit (Hct) and the VAS scale scores increased significantly with the ESAs and IV-iron treatment. There was a highly significant correlation between the ∆Hb and ∆VAS; rs = 0.71 p = 0.009 and between the ∆Hct and ∆VAS; rs = 0.8 p = 0.0014.

CONCLUSIONS

ID is common in COPD patients but is rarely looked for or treated. Yet correction of the ID in COPD patients with ESAs and IV iron can improve the anemia, the ID, and may improve the dyspnea.

Erythrocyte osmotic resistance recovery after lung volume reduction surgery

OBJECTIVES

Alteration of erythrocyte osmotic resistance, with increment of reticulocytes, is common in emphysema. This fragility is probably due to an altered fatty acid membrane composition from lipid peroxidation, a reaction triggered by the disease-related increment of reactive oxidative species. We analysed the effects of lung volume reduction surgery (LVRS) on this anomaly compared with respiratory rehabilitation (RR) therapy.

METHODS

We retrospectively compared 58 male patients with moderate-to-severe emphysema who underwent LVRS with 56 similar patients who underwent standardized RR. Respiratory function parameters, erythrocyte osmotic resistance and antioxidant enzymes levels were evaluated before and 6 months after treatments.

RESULTS

Significant improvements in respiratory function, exercise capacity, unsaturated fatty acid content (+10.0%, P = 0.035), erythrocyte osmotic resistance (hyperosmolar resistance -21.0%, P = 0.001; hyposmolar resistance -18.0%, P = 0.007) and erythrocyte antioxidant enzymes [superoxide dismutase (SOD) +60.0%, P < 0.001; glutathione peroxidase +39.0%, P = 0.004 and glutathione reductase +24.5%, P = 0.008] were observed after surgery. In the RR group, we did not find any significant improvements in osmotic resistance, although respiratory and functional parameters were significantly improved. Correlation analysis in the surgical group showed that the reduction in residual volume (RV) significantly correlated the normalization of hyperosmotic (P = 0.019) and hyposmotic resistances (P = 0.006), the decrease in the absolute number of reticulocytes (P = 0.037) and increase in SOD (P < 0.001).

CONCLUSIONS

LVRS improved unsaturated fatty acid content, erythrocyte osmotic resistance and levels of erythrocyte antioxidant enzymes compared with RR. Correlations between erythrocyte osmotic resistance and antioxidant intracellular enzymes with RV suggest that reduction in lung hyperinflation with the elimination of inflammatory emphysematous tissue may explain such improvements after surgery.

Unsuspected risk factors of frequent exacerbations requiring hospital admission in chronic obstructive pulmonary disease

INTRODUCTION

Severe exacerbations are the leading cause of fatal events in chronic obstructive pulmonary disease (COPD). The new Global Initiative for Chronic Obstructive Lung Disease strategy included the number of exacerbations in the grading of the disease. The primary aim of this study was to evaluate the potentially modifiable precipitating factors of frequent severe exacerbations requiring hospital admission in COPD. The secondary aim was to investigate the risk factors of readmission within 2 months following an exacerbation requiring hospitalisation.

METHODS

Data regarding the number of exacerbations in the previous year, current comorbidities, medications, and clinical and functional status of COPD patients were evaluated.

RESULTS

We included 107 COPD patients (85% men). The mean number of severe exacerbations was 1.3 ± 1.7 (per patient/per year), and 37.4% of the patients had frequent severe exacerbations (≥ 2/year). Multivariate analysis indicated that haematocrit < 41%, angiotensin converting enzyme inhibitor or angiotensin receptor blocker use, positive gastro-oesophageal reflux disease symptoms, poor adherence to inhaled therapy/regular outpatient follow-up visits and FEV1 < 50% were independent predictors of frequent severe exacerbations. Readmission rate within 2 months after hospital discharge was 39.3%. The independent risk factors of readmission were poor adherence to inhaled therapy/regular outpatient follow-up visits, serum haematocrit < 41%, and FEV1 < 50%.

CONCLUSION

Chronic obstructive pulmonary disease patients with frequent exacerbations should be carefully assessed for modifiable confounding risk factors regardless of poor lung function to decrease exacerbation frequency and related poor prognosis.

Anaemia in chronic obstructive pulmonary disease. Does it really matter?

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent chronic diseases, with an increasing rate in morbidity and mortality. In recent years, there has been a greater awareness about the clinical importance of systemic effects and other chronic conditions associated with COPD, as these significantly impact on the course of disease. The most studied extrapulmonary manifestations in COPD include the presence of concomitant cardiovascular disease, skeletal muscle wasting, osteoporosis and lung cancer. Anaemia is a recognised independent marker of mortality in several chronic diseases. Recent studies have shown that anaemia in patients with COPD may be more frequent than expected, with a prevalence ranging from 5% to 33%. Some evidence suggests that systemic inflammation may play an important pathogenic role, but anaemia in COPD is probably multifactorial and may be caused by others factors, such as concealed chronic renal failure, decreased androgenic levels, iron depletion, angiotensin-converting enzyme inhibitor treatment and exacerbations. Low levels of haemoglobin and haematocrit in COPD patients have been associated with poor clinical and functional outcomes as well as with mortality and increased healthcare costs. Despite the potential clinical benefit of successfully treating anaemia in these patients, evidence supporting the importance of its correction on the prognosis of COPD is uncertain.

Fetuin-A is associated with disease severity and exacerbation frequency in patients with COPD

Fetuin-A is a liver protein that may serve as an inhibitor of systemic inflammation in humans. In the present study we assessed the levels of fetuin-A in COPD patients in stable condition and on exacerbation in an attempt to evaluate it as a clinically relevant biomarker that may serve as predictor of exacerbations of COPD (ECOPD). One hundred COPD outpatients (GOLD stage I to IV) were enrolled in a tertiary University hospital and were submitted to a detailed evaluation, including pulmonary function testing, exercise capacity, quality of life and evaluation of the presence of metabolic syndrome and serum CRP. All patients were followed-up for 1 year, and 36 were re-evaluated at the onset of an ECOPD. Forty otherwise healthy smokers served as controls. Serum fetuin-A levels were reproducible at baseline, 6 and 12 months. COPD patients presented lower levels of fetuin compared to controls [394.5 (321.8-419.6) vs. 487.3 (441.0-548.0) mg/L, p < 0.001]. COPD patients with GOLD stage IV had lower fetuin-A levels compared to stages I-II and III (p < 0.05). Fetuin-A was significantly reduced at the onset of an ECOPD compared to baseline (p < 0.001) and the time to the first ECOPD significantly different between patients with high and low levels of fetuin-A [HR 2.163 (95%CI 1.104-4.238), p = 0.024). The results of the present study suggest that fetuin-A is a reproducible and clinically relevant biomarker in patients with COPD that may be useful in the identification of exacerbation-prone patients.

Levels of inflammatory mediators in chronic obstructive pulmonary disease patients with anemia of chronic disease: a case-control study

BACKGROUND

Although a subset of patients with chronic obstructive pulmonary disease (COPD) display anemia, the role of elevated pro-inflammatory cytokines in COPD-related anemia of chronic disease (ACD) has not been fully investigated.

AIM

To examine the levels of interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor-alpha (TNFα), interferon-gamma (IFNγ), C-reactive protein (CRP) and erythropoietin in stable COPD outpatients with and without ACD.

DESIGN

A case-control design was followed.

METHODS

Fifty-four patients with stable COPD were studied. Among them, 27 had ACD according to strict clinical and laboratory criteria (group of cases), while another 27 nonanemic COPD patients, carefully matched to cases for age, gender, height, lung function and smoking status represented the controls. Serum levels of IL-1β, IL-6, IL-10, TNFα, IFNγ, CRP and erythropoietin were measured in both groups.

RESULTS

Patients with ACD had significantly higher levels of IL-10 [25.6 (1.9-95.2) vs. 4.1 (1.9-31.9) pg/ml, P = 0.049] and IFNγ [15.2 (2.2-106.9) vs. 2 (1.2-18.3) pg/ml, P = 0.026] and had more frequently elevated CRP than controls. Levels of IL-1β [26.2 (9.8-96.4) vs. 7.9 (2.1-28.4) pg/ml, P = 0.073], IL-6 [20.3 (2.1-125.4) vs. 6.2 (1.2-33.8) pg/ml, P = 0.688] and TNFα [30.1 (3.2-107.5) vs. 10.1 (3.2-50.4) pg/ml, P = 0.131] were also higher in cases, but the differences did not reach statistical significance. Patients with ACD also displayed significantly higher erythropoietin levels than controls [(21.9 (8.4-101.7) vs. 9.7 (6.3-21.7) mIU/ml, P = 0.010], indicating erythropoietin resistance.

CONCLUSION

This study shows that in stable COPD outpatients with strictly defined ACD, levels of inflammatory mediators and erythropoietin are elevated compared to nonanemic controls.

Extrapulmonary comorbidities in chronic obstructive pulmonary disease: state of the art

Extrapulmonary comorbidities are common and significant in chronic obstructive pulmonary disease (COPD), often contributing to symptoms, exacerbations, hospital admissions and mortality. Cardiovascular, musculoskeletal and psychological conditions are among the most prevalent and important of these. In particular, ischemic heart disease is a leading cause of death in the COPD population as a whole. Here, we provide a state-of-the-art summary of key comorbidities observed in COPD patients in terms of their prevalence, impact, pathophysiology and prognosis. In addition, we review clinical, diagnostic and management strategies that may differ in COPD patients from the rest of the population.