Relationship between red cell distribution width and right ventricular dysfunction in patients with chronic obstructive pulmonary disease

Predictive role of red blood cell distribution width and hemoglobin-to-red blood cell distribution width ratio for mortality in patients with COPD: evidence from NHANES 1999-2018

BACKGROUND

Higher red blood cell distribution width (RDW) levels are associated with mortality in patients with chronic obstructive pulmonary disease (COPD). However, more convincing evidence is still lacking, and the relationship between hemoglobin-to-red blood cell distribution width ratio (HRR) and mortality in patients with COPD remains unclear.

METHODS

This study is a prospective cohort study that includes 3,745 adult patients with COPD from the National Health and Nutrition Examination Survey (NHANES) database spanning from 1999 to 2018 in the United States. COX proportional hazards regression analysis, Kaplan-Meier survival curves and restricted cubic spline models were employed to investigate the association of RDW and HRR levels with mortality. Time-dependent receiver operating characteristic curve (ROC) analysis was conducted to evaluate the accuracy of RDW and HRR in predicting mortality in patients with COPD.

RESULTS

Higher RDW level was positively associated with increased risk of all-cause mortality (HR = 1.16, 95% CI = 1.11-1.21, P < 0.001), cardiovascular disease (CVD) mortality (HR = 1.13, 95% CI = 1.06-1.21, P < 0.001), and chronic lower respiratory disease (CLRD) related mortality (HR = 1.15, 95% CI = 1.05-1.25, P = 0.003) after adjusting for various potential confounders. HRR was inversely associated with all-cause mortality (HR = 0.14, 95% CI = 0.08-0.25, P < 0.001), CVD mortality (HR = 0.12, 95% CI = 0.05-0.31, P < 0.001). HRR has no significant correlation with CLRD-related mortality. The time-dependent ROC curve showed that RDW exhibited area under the curves (AUCs) of the 5- and 10-year survival rates were 0.707 and 0.714 for all-cause mortality and 0.686 and 0.698, respectively, for CVD mortality. HRR yielded AUCs of the 5- and 10-year survival rates were 0.661 and 0.653 for all-cause mortality and 0.654 and 0.66, respectively, for CVD mortality.

CONCLUSION

Higher RDW levels were positively associated with an increased risk of mortality in patients with COPD. HRR levels were negatively correlated with the risk of all-cause and CVD mortality. The predictive value of HRR for mortality in these patients is lower than that of RDW.

Relationship between neutrophil lymphocyte ratio and red blood cell distribution width and respiratory failure in COPD patients

The neutrophil lymphocyte ratio (NLR) and red blood cell distribution width (RDW) have been repeatedly demonstrated to be associated with risk of severity, progression, and prognosis of chronic obstructive pulmonary disease (COPD), but data on respiratory failure (RF) in patients with COPD are very limited. This study aimed to examine the relationship between NLR and RDW and the incident RF in patients with COPD. This is a retrospective study that reviewed data by examining the hospitalization medical records to identify those who were admitted with a diagnosis of COPD. Based on whether RF occurred during index hospitalization, patients were classified as COPD group and COPD combined with RF group. Also, healthy controls of the same age and sex were enrolled in a 1:1 ratio as the COPD group. Univariate comparisons were performed between three groups to examine differences. With the COPD group as reference, multivariable logistic regression was formed to identify the relationship between NLR and RDW and RF, with adjustment for multiple covariates. There were 136 healthy controls, 136 COPD patients and 62 patients with COPD combined with RF included for analysis. There was a significant difference for eight variables, including age, WBC, neutrophil, NLR, RDW, platelet, PLR, and CRP. The Spearman test showed the significant correlation between NLR and WBC (correlation coefficient, 0.38; P = .008), NLR and RDW (correlation coefficient, 0.32; P = .013), and NLR and CRP level (correlation coefficient, 0.54; P < .001). The multivariable logistic regression showed that age (every additional 10 years) (OR, 1.785), NLR (OR, 1.716), RDW (OR, 2.266), and CRP (OR, 1.163) were independently associated with an increased risk of RF. This study demonstrated the independent associative effect of NLR and RDW with RF in patients with COPD, exhibiting the potential clinical role in evaluating the progress of COPD to RF.

The relationship between red cell distribution width, serum calcium ratio, and in-hospital mortality among patients with acute respiratory failure: A retrospective cohort study of the MIMIC-IV database

To investigate the impact of RDW/CA (the ratio of red cell distribution width to calcium) on in-hospital mortality in patients with acute respiratory failure (ARF). This retrospective cohort study analyzed the data of 6981 ARF patients from the Medical Information Mart for Intensive Care (MIMIC-IV) database 2.0. Critically ill participants between 2008 and 2019 at the Beth Israel Deaconess Medical Center in Boston. The primary outcome of interest was in-hospital mortality. A Cox proportional hazards regression model was used to determine whether the RDW/CA ratio independently correlated with in-hospital mortality. The Kaplan-Meier method was used to plot the survival curves of the RDW/CA. Subgroup analyses were performed to measure the mortality across various subgroups. After adjusting for potential covariates, we found that a higher RDW/CA was associated with an increased risk of in-hospital mortality (HR = 1.17, 95% CI: 1.01-1.35, P = .0365) in ARF patients. A nonlinear relationship was observed between RDW/CA and in-hospital mortality, with an inflection point of 1.97. When RDW/CA ≥ 1.97 was positively correlated with in-hospital mortality in patients with ARF (HR = 1.554, 95% CI: 1.183-2.042, P = .0015). The Kaplan-Meier curve indicated the higher survival rates for RDW/CA < 1.97 and the lower for RDW/CA ≥ 1.97 after adjustment for age, gender, body mass index, and ethnicity. RDW/CA is an independent predictor of in-hospital mortality in patients with ARF. Furthermore, a nonlinear relationship was observed between RDW/CA and in-hospital mortality in patients with ARF.

Red cell distribution in critically ill patients with chronic obstructive pulmonary disease

BACKGROUND

Red blood cell distribution width (RDW) is associated with increased mortality risk in patients with chronic obstructive pulmonary disease (COPD). However, limited data are available for critically ill patients with COPD.

METHODS

Data from the Medical Information Mart for Intensive Care III V1.4 database were analyzed in this retrospective cohort research. The International Classification of Diseases codes were used to identify critically ill patients with COPD. The first value of RDW was extracted within the first 24 h after intensive care unit admission. The endpoint was 28-day all-cause mortality. Multivariable logistic regression analysis was performed to examine the relationship between RDW and 28-day mortality. Age, sex, ethnicity, anemia status, comorbidities, clinical therapy, and disease severity score were considered for subgroup analysis.

RESULTS

A total of 2,344 patients were included with mean (standard deviation) age of 72.3 (11.3) years, in which 1,739 (53.6%) patients were men. The increase in RDW was correlated with an increased risk of 28-day mortality in the multivariate logistic regression model (odds ratio [OR] 1.15; 95% confidence interval [CI] 1.09-1.21). In comparison with the low-RDW group, the middle and high-RDW groups tended to have higher risks of 28-day all-cause mortality (OR [95% CI] 1.03 [0.78-1.34]; OR [95% CI] 1.70 [1.29-2.22]; P trend < 0.0001). Subgroup analyses show no evidence of effect modifications on the correlation of RDW and 28-day all-cause mortality.

CONCLUSION

An increase in RDW was associated with an increased risk of 28-day all-cause mortality in critically ill patients with COPD. Further studies are required to investigate this association.

Increased Red Blood Cell Distribution Predicts Severity of Chronic Obstructive Pulmonary Disease Exacerbation

INTRODUCTION

Increased red blood cell distribution width (RDW) has been reported to be related to underlying chronic inflammation. Our aim is to investigate the relationship of different complete blood count (CBC) parameters such as hemoglobin level, mean corpuscular volume (MCV), mean platelet volume (MPV) or RDW with COPD exacerbation severity.

METHODS

In the present retrospective analysis, consecutive patients admitted with the diagnosis of "COPD Exacerbation" between 1 January 2012 and 31 December 2015 were evaluated.

RESULTS

The study population included 804 patients with COPD exacerbation. The maximal partial pressure of carbon dioxide in the arterial blood (PaCO₂) during hospital stay was significantly higher in patients with high MCV (p < 0.001), and in patients with a high RDW (p < 0.001). The hospitalization duration was significantly longer in patients with high RDW (p < 0.001) and in patients with elevated C-reactive protein (CRP) levels (p < 0.001). CRP levels strongly correlated to RDW (p = 0.001).

CONCLUSIONS

Our study demonstrated that different CBC parameters, such as MCV and RDW, are in correlation with the severity of acute exacerbation of COPD reflected by the PaCO₂ level and the duration of hospitalization. Furthermore, we also found a positive correlation between RDW and CRP levels. This finding supports the hypothesis that RDW is a good biomarker of acute inflammation.

The Emerging Clinical Significance of the Red Cell Distribution Width as a Biomarker in Chronic Obstructive Pulmonary Disease: A Systematic Review

There is an intense focus on the identification of novel biomarkers of chronic obstructive pulmonary disease (COPD) to enhance clinical decisions in patients with stable disease and acute exacerbations (AECOPD). Though several local (airway) and circulatory inflammatory biomarkers have been proposed, emerging evidence also suggests a potential role for routine haematological parameters, e.g., the red cell distribution width (RDW). We conducted a systematic literature search in PubMed, Web of Science, and Scopus, from inception to April 2022, for articles investigating the diagnostic and prognostic role of the RDW in stable COPD and AECOPD. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. Significant associations between the RDW and the presence and severity of disease, outcomes (mortality, hospital readmission), and other relevant clinical parameters (right heart failure, pulmonary arterial hypertension) were reported in 13 out of 16 studies in stable COPD (low risk of bias in 11 studies), and 17 out of 21 studies of AECOPD (low risk of bias in 11 studies). Pending further research, our systematic review suggests that the RDW might be useful, singly or in combination with other parameters, for the diagnosis and risk stratification of patients with stable COPD and AECOPD (PROSPERO registration number: CRD42022348304).

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.

Exploring red cell distribution width as a biomarker for treatment efficacy in home mechanical ventilation

BACKGROUND

With the growing practice of home mechanical ventilation, there is a need to identify biological markers for adequate follow-up. Red cell distribution width (RDW) is a promising candidate because it is convenient, objective and may reflect treatment effect over a long period of time. The aim of this study was to explore the possible role of RDW as a marker for home mechanical ventilation in real-life, unselected chronic respiratory patient populations.

METHODS

First, we identified characteristic RDW values for mixed case, unselected chronic respiratory failure and home mechanical ventilated patients through retrospective review within our institutional database. Next, we conducted a prospective observational study to identify RDW changes during the first six months of optimized home mechanical ventilation treatment. Adult patients starting home mechanical ventilation were included. Factors affecting RDW change during the first 6 months of treatment were analysed.

RESULTS

RDW was elevated in both chronic respiratory failure and home mechanical ventilation patients compared to healthy individuals in the retrospective review. In the prospective study of 70 patients, we found that 55.4% of patients starting home mechanical ventilation have abnormal RDW values which are reduced from 14.7 (IQR = 13.2-16.2)% to 13.5 (IQR = 13.1-14.6)% during the first 6 months of HMV treatment (p < 0.001). RDW improvement correlates with improvement in self-reported health-related quality of life and sleepiness scale scores, as well as physical functional status during the same time frame. RDW proved to be a comparable marker to other parameters traditionally used to evaluate treatment efficacy.

CONCLUSIONS

RDW is elevated in chronic respiratory failure patients and is significantly reduced in the first six months of optimized home mechanical ventilation. Although further research is needed to verify if RDW change reflects outcome and how comorbidities influence RDW values, our results suggest that RDW is a promising marker of home mechanical ventilation efficacy. Trial registration This study was approved by and registered at the ethics committee of Semmelweis University (TUKEB 250/2017 and TUKEB 250-1/2017, 20th of December 2017 and 1st of October 2019).

The role of elevated red blood cell distribution width in the prognosis of AECOPD patients: A retrospective study

Chronic obstructive pulmonary disease (COPD) is still a constant threat to people's health. We aimed to identify the relationship between increased red cell distribution width (RDW) on admission and length of hospitalization in acute exacerbation of chronic obstructive pulmonary disease patients (AECOPD).Patients with AECOPD were recruited and divided into 3 groups based on RDW tertiles.Two hundred eighty six patients with AECOPD admitted to our department during January 1, 2017 and June 30, 2019 were enrolled in the study. According to the RDW tertiles (≤12.8%, 12.9% to 13.6%, >13.6%), the patients were divided into 3 groups. Length of stay was significantly related to RDW (P < .001) in AECOPD patients. Correlation analysis indicated that RDW was negatively associated with FEV1% predicted (r = -0.142, P = .016). However, RDW was positively associated with prolonged of stay (r = 0.298, P < .001) in AECOPD patients. Multivariate regression analysis discovered that RDW was independently associated with the length of hospitalization (P = .001). Receiver operating characteristic (ROC) curve showed that RDW was a good predictor of prolonged hospital stay in AECOPD patients, and the area under the curve (AUC) was 0.818 (95% CI: 0.769-0.868). The highest sensitivity to predict prolonged hospital stay was 83.8% and the specificity was 71.6% with the cut-off 13.35%.In conclusion, prolonged hospital stay in AECOPD patients was closely associated with increased RDW. Elevated RDW may be an independent predictor for prolonged hospitalization in AECOPD patients.

Dynamic Increase of Red Cell Distribution Width Predicts Increased Risk of 30-Day Readmission in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

Studies have demonstrated that red blood cell distribution width (RDW) is closely associated with the prognosis of patients with chronic obstructive pulmonary disease (COPD). In addition, the dynamic changes in RDW appear to play an important role. Thus, we aimed to investigate the relationship between dynamic changes in RDW and 30-day all-cause readmission of patients with acute exacerbation of COPD (AECOPD).

Methods

In this retrospective cohort study, we enrolled patients with AECOPD hospitalized in the Department of Respiratory Medicine in Liyuan Hospital (Wuhan China), a tertiary, university-affiliated, public hospital. Patients with AECOPD were divided into three groups based on their RDW values after the first and fourth days of admission. The normal range for RDW is 10-15%. Patients with normal RDW values were included in the normal group. Patients with an RDW value >15% on the first day, which subsequently decreased by >2% on the fourth day was included in the decreased group. The increased group was comprised of patients with an RDW value >15% on the first day which continued to increase, or those with a normal RDW value on the first day which increased >15% on the fourth day.

Results

A total of 239 patients (age: 72 years [range: 64-81 years]; male: n=199 [83.3%]) were included. There were 108, 72, and 59 patients in the RDW normal, decreased, and increased groups, respectively; the 30-day all-cause readmission rate was 9.3%, 9.7%, 27.1%, respectively; (p=0.003), being noticeably higher in the RDW increased group. Dynamic increase of RDW (OR:3.45, 95% CI: 1.39-8.58, p= 0.008) was independently correlated with 30-day all-cause readmission of patients with AECOPD.

Conclusion

The dynamic increase of RDW is an independent prognostic factor of 30-day all-cause readmission of patients with AECOPD.

Importance of haemogram parameters for prediction of the time of birth in women diagnosed with threatened preterm labour

Objective

This study aimed to estimate the importance of complete blood count parameters for predicting the timing of birth in threatened preterm labour cases.

Methods

We performed a retrospective study of 92 patients who were diagnosed with threatened preterm labour (24–34 gestational weeks). The patients were divided into two groups according to the time of birth (group 1: delivered within the first week after diagnosis; group 2: delivered later than 1 week). We compared characteristics and complete blood count parameters between these two groups.

Results

There were no significant differences in maternal age, body mass index, gravida, parity, haemoglobin levels, and gestational weeks between the two groups. The mean cervical length was 24.24 ± 3.60 mm in group 1 and 30.70 ± 5.32 mm in group 2. There were significant differences in the neutrophil to lymphocyte ratio, white blood cell count, red cell distribution width (RDW), absolute lymphocyte cell count, and absolute neutrophil cell count between the two groups.

Conclusion

Maternal serum RDW, the neutrophil to lymphocyte ratio, white blood cell count, absolute lymphocyte cell count, and the absolute neutrophil cell count profile could guide clinicians in predicting the time of birth in threatened preterm labour cases.

A narrative review of red blood cell distribution width as a marker for pulmonary embolism

Red blood cell distribution width (RDW) is a marker of variability in red blood cell size, and is routinely reported as part of a patient's complete blood count. RDW has been shown to be associated with the prediction, severity and prognosis of pulmonary embolism (PE) in recent studies. The underlying biomolecular mechanism of the relationship of RDW to PE is largely unknown, but is thought to be due to the relationship of RDW with acute inflammatory markers and variations in blood viscosity. This review substantiates that a high RDW level, defined using either an arbitrary number or according to receiver operator curve statistics, is associated with a higher risk of acute PE, increased severity (massive vs. submassive) of PE and increased mortality in patients with PE. Nevertheless, the comparison of current studies is limited due to the definition of high RDW (each study uses a different RDW cutoff level), the broad range of exclusion criteria and the inclusion of differing modalities used to diagnose a PE (computed tomography angiogram, ventilation-perfusion study, or clinical diagnosis). Despite the above limitations, these studies provide a promising future clinical use for RDW as a marker of PE.

The role of increased red cell distribution width as a negative prognostic marker in patients with COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) remains a major burden with no clinically applicable biomarkers.

AIM

To investigate the association of Red cell Distribution Width (RDW) values on admission with previous hospitalizations, need of non-invasive mechanical ventilation (NIMV) and long term oxygen therapy (LTOT) in patients with COPD.

METHODS

Patients with AECOPD admitted to our department during 2018 were included in the study.

RESULTS

One hundred sixty patients were enrolled (M/F 95/65, median age 71.00 years, mean FEV₁± SD = 46.6 ± 28.9). Median RDW was significantly higher for patients in need of NIMV (14.8, 95% CI: 14.2 to 15.6) than patients not in need of NIMV (13.5, 95% CI: 13.2 to 13.8) (p < 0.001). Median RDW was significantly higher for patients in need of LTOT (14.2, 95% CI: 13.7 to 14.6) compared to patients not receiving LTOT (13.2, 95% CI: 12.5 to 13.6) (p = 0.001). Patients with hospitalization during the last 12 months had increased RDW values compared to patients with no hospitalizations [median RDW 14.3, (95% CI: 13.5 to 14.9) versus median RDW 13.5, (95% CI: 13.1 to 13.9)](p = 0.001).

CONCLUSION

Patients with COPD in need of LTOT, NIMV or patients with previous hospitalizations presented with increased RDW values. Increased RDW values could serve as a negative prognostic marker in patients with COPD.

Red Blood Cell Distribution Width Predicts Pulmonary Hypertension Secondary to Chronic Obstructive Pulmonary Disease

Purpose

This study aims at investigating the predictive value of red blood cell distribution width (RDW) in pulmonary hypertension (PH) secondary to chronic obstructive pulmonary disease (COPD).

Methods

213 eligible in-hospital COPD patients were reviewed between May 2016 and May 2018, including 39 cases with PH and 174 without PH. Clinical data including demographic characteristics, comorbidities, and results of ultrasound scans, imaging examinations, and laboratory tests were recorded.

Results

Increased RDW level was observed in COPD patients with PH compared with COPD patients without PH, with 15.10 ± 1.72% versus 13.70 ± 1.03%, respectively (p < 0.001). RDW shared positive relationships with brain natriuretic peptide (BNP) (p=0.001, r = 0.513), pulmonary artery (PA) systolic pressure (p=0.014, r = 0.390), and PA-to-ascending aorta (A) ratio (PA : A) (p=0.001, r = 0.502). Multivariate analysis indicated that RDW, BNP, and PA : A > 1 were the independent risk factors of PH secondary to COPD (p < 0.05). The AUC of the RDW in patients with PH was 0.749 ± 0.054 (p < 0.001). The optimal cutoff value of RDW for predicting PH was 14.65, with a sensitivity and a specificity value of 69.2% and 82.8%, respectively.

Conclusion

RDW is significantly increased in COPD patients with PH and thus may be a useful biomarker for PH secondary to COPD.

Use of red cell distribution width in a population at high risk for pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) often presents with non-specific symptoms making early diagnosis difficult. Red cell distribution width (RDW) is a parameter routinely reported on an automated complete blood cell count that has been associated with numerous disease states. The purpose of this study was to further evaluate RDW as a biomarker for PH in at-risk populations.

METHODS

In a retrospective, cross-sectional analysis of patients seen at a PH center over 1 year, we examined both patients with PH and patients at risk for but without PH (e.g. systemic sclerosis, [SSc]). We also studied a group of age-and sex-matched, non-diseased controls. Relevant characteristics were compared among the 3 groups using one-way ANOVA. Similar comparisons were made across World Health Organization (WHO) PH groups 1-4.

RESULTS

RDW was highest in the PH patients (n = 181), intermediate in the at-risk for PH patients (n = 52), and lowest in matched controls (n = 100) (15.9 ± 2.8 vs 14.8 ± 2.8 vs 14.2 ± 1.1%, respectively; p < 0.0001). There were no significant differences in RDW across WHO PH groups (p = 0.50). SSc patients with PH had significantly higher RDW values compared to SSc patients without PH (16.0 ± 2.2 vs 14.4 ± 1.9%, respectively; p = 0.03).

CONCLUSIONS

RDW is significantly higher in PH patients, without regard to disease etiology, when compared to age- and sex-matched non-diseased controls. Importantly, RDW is also higher in PH patients compared to at-risk patients, particularly in the SSc cohort. The ease of obtaining RDW as a biomarker may help detect incident PH at earlier stages among patients who are at high risk for development of PH.

Red cell distribution width (RDW) as a biomarker for respiratory failure in a pediatric ICU

Background

The red cell distribution width (RDW) is a widely available, inexpensive, and highly reproducible test that reflects the range of the red cell sizes. Any process that releases reticulocytes in the circulation will result in an increase in RDW. Elevated RDW values are linked to worsened pulmonary function in the adult population. We performed a retrospective cohort study to describe the association between RDW and respiratory failure in critically ill children in a in a pediatric intensive care unit (PICU) in a tertiary university hospital.

Subjects

All patients admitted between January 2009 and June 2015 were considered eligible for inclusion.

Methods

Retrospective cohort study.

Results

In total, 960 patients were included in the cohort analysis. Of those patients, 149 (15.5%) had elevated RDW values. RDW on admission was associated with lower 28 day ventilator-free days. The highest quintile of RDW was associated with the need for mechanical ventilation, even when correcting for anaemia, age and Pediatric Risk of Mortality (PRISM) scores. In the subgroup of ventilated patients, RDW was associated with nadir PaO₂/FiO₂(P/F) ratios.

Conclusion

The RDW value on admission of our PICU patients is associated with a greater need for invasive mechanical ventilation, lower 28 day ventilator-free days and lower nadir P/F ratios in the patients with highest RDW values on admission. RDW may be a valuable, cheap and universally available, prognostic parameter for respiratory dysfunction in the PICU.

Toward a Blood-Borne Biomarker of Chronic Hypoxemia: Red Cell Distribution Width and Respiratory Disease

Hypoxemia (systemic oxygen desaturation) marks the presence, risk, and progression of many diseases. Episodic or nocturnal hypoxemia can be challenging to detect and quantify. A sensitive, specific, and convenient marker of recent oxygen desaturation represents an unmet medical need. Observations of acclimatization to high altitude in humans and animals reveals several proteosomic, ventilatory, and hematological responses to low oxygen tension. Of these, increased red cell distribution width (RDW) appears to have the longest persistence. Literature review and analyses of a 2M patient database across the full disease pathome revealed that increased RDW is predictive of poor outcome for certain diseases including many if not all hypoxigenic conditions. Comprehensive review of diseases impacting the respiratory axis show many are associated with increased RDW and no apparent counterexamples. The mechanism linking RDW to outcome is unknown. Conjectural roles for iron deficiency, inflammation, and oxidative stress have not been born out experimentally. Sports-doping studies show that erythropoietin (EPO) injection can induce formation of unusually large red blood cells (RBC) in sufficient numbers to increase RDW. Because endogenous EPO responds strongly to hypoxemia, this molecule could potentially mediate a long-lived RDW response to low oxygenation. RDW may be a guidepost signaling that unexploited information is embedded in subtle RBC variation. Applying modern techniques of measurement and analysis to certain RBC characteristics may yield a more specific and sensitive marker of chronic pulmonary and circulatory diseases, sleep apnea, and opioid inhibition of breathing.

Red Blood Cell Distribution Width, Hematology, and Serum Biochemistry in Dogs with Echocardiographically Estimated Precapillary and Postcapillary Pulmonary Arterial Hypertension

Background

Red blood cell distribution width (RDW) is a quantitative measurement of anisocytosis. RDW has prognostic value in humans with different cardiovascular and systemic disorders, but few studies have investigated this biomarker in dogs.

Objectives

To compare the RDW in dogs with precapillary and postcapillary pulmonary hypertension (PH) and a control population of dogs and to correlate RDW with demographic, echocardiographic, and laboratory variables.

Animals

One hundred and twenty‐seven client‐owned dogs including 19 healthy dogs, 82 dogs with myxomatous mitral valve disease (50 dogs without PH and 32 dogs with postcapillary PH), and 26 dogs with precapillary PH.

Methods

Prospective study. Dogs were allocated to groups according to clinical and echocardiographic evaluation. RDW and selected laboratory and echocardiographic variables were compared among dog groups. Associations between RDW and demographic, laboratory, and echocardiographic variables were analyzed using correlation and multiple regression analysis.

Results

Median RDW in dogs with precapillary PH (13.8%, interquartile range 13.2–14.9%) and postcapillary PH (13.7, 13.2–14.7%) was significantly increased compared to healthy dogs (13.3, 12.3–13.7%; P < .05 for both comparisons), but only dogs with severe PH had significantly increased RDW compared to dogs without PH (P < .05). Peak tricuspid regurgitation pressure gradient was significantly associated with increased RDW (rho = 0.263, P = .007). Serum urea concentration, hematocrit, age, and white blood cell number were significantly associated with RDW in the multivariate analysis.

Conclusions and Clinical Importance

Underlying pathophysiologic processes associated with PH instead of severity of PH are likely responsible for increased RDW in dogs with PH.

Red cell distribution width in predicting 30-day mortality in patients with pulmonary embolism

PURPOSE

The aim of the study was to investigate red cell distribution width (RDW) in predicting 30-day mortality in patients with pulmonary embolism (PE).

METHODS

A single-center, retrospective study design was used between January 1, 2014, and February 1, 2016. The primary end point was 30-day mortality after admission. The RDW predicting value was assessed by receiver operating characteristic curves and area under the curve.

RESULTS

A total of 309 patients with PE were included. The 30-day mortality was 14.9% (46/309). The mean RDW level was 13.9%±0.6% (range, 10.7%-21.9%) at admission. The 30-day mortality was higher in the high-RDW-level group compared with the normal-RDW-level group (12.5% vs 23.5%, χ²=5.140, P=.023), with an odds ratio of 2.164 (95% confidence interval [CI], 1.019-4.450). Logistic regression showed that presence of shock, RDW level, and simplified pulmonary embolism severity index (sPESI) were independent risk factors for 30-day mortality in patients with PE. After adjustment by these risk factors, the adjusted odds ratio was 1.439 (95% CI, 1.024-2.116). The area under the curve for RDW predicting the 30-day mortality was 0.6646 (95% CI, 0.5585-0.7518). The cutoff was 16%. The Youden index for RDW and sPESI was 0.400 and 0.453, respectively. When adding RDW into sPESI, the modified sPESI showed highest prediction accuracy, with Youden index 0.499.

CONCLUSIONS

Our results suggested that the RDW is a simple and useful indicator in predicting 30-day mortality in patients with PE. However, this conclusion showed be confirmed by prospective study with large sample.

Red Blood Cell Distribution Width in Patients With Chronic Obstructive Pulmonary Disease and Healthy Subjects

BACKGROUND

Chronic obstructive pulmonary disease (COPD) increases the risk of cardiovascular disease (CVD). Red blood cell distribution width (RDW) is accepted as a powerful predictor of outcomes in patients with CVD.

AIMS

To study RDW in patients with COPD, and to compare the value of this measurement with clinical, echocardiographic, nutritional and laboratory status. Secondly, we aimed to determine the effect of smoking on RDW values in healthy subjects.

METHODS

One hundred and seventy-five patients with stable COPD and 210 healthy controls were enrolled in the study. Demographic, clinical, nutritional status, echocardiographic, and laboratory characteristics, RDW values were recorded and compared.

RESULTS

RDW values were higher in the COPD group than in controls (15±2.3% vs. 13.8±2.5%, p<0.001). In COPD patients, RDW levels positively correlated with CRP levels (r=0.27, P<.001), albumin levels (r=0.23, P=.04), right ventricular dysfunction (RVD) (r=0.24, P=.001), pulmonary hypertension (PAH) (r=0.1, P=.02), and presence of CVD (r=0.24, P=.02). In multivariable logistic regression suggested that presence of CVD (4.3; 95% CI: 1.3 to 11; P=.01), and presence of RVD (3.1; 95% CI: 1.7 to 8.3; P=.02) were independently related to elevated RDW levels in COPD patients. In the healthy population, correlations analysis showed only a significant correlation between RDW and cigarette smoking years (r=0.57, P<.001).

CONCLUSION

RDW is independently associated with CVD and RVD in patients with COPD. In the healthy population, RDW is also associated with smoking status.

Effect of the polydispersity of RBCs on the recovery rate of RBCs during the removal of CPAs

In the process of removing cryoprotectants from cryopreserved blood, the theoretically optimal operating condition, which is based on the assumption that the distribution of red blood cells is uniform, is often used to reduce or even avoid the hypotonic damage to cells. However, due to the polydispersity of cells, the optimal condition is actually not reliable. In this study, based on the discrete concept developed in our previous work, the effect of the polydispersity on the recovery rate of cells in the dilution-filtration system was statistically investigated by assigning three random parameters, isotonic cell volume, cell surface area, and osmotically inactive cell volume, to cells in small units of blood. The results show that, due to the polydispersity, the real recovery rate deviates from the ideal value that is based on uniform distribution. The deviation significantly increases with the standard errors of cell parameters, and it can be also magnified by high cryoprotectant concentrations. Under the effect of polydispersity, the uniform distribution-based optimized blood or diluent flow rate is not perfect. In practice, one should adopt a more conservative blood or diluent flow rate so that the hypotonic damage to cells can be further reduced.

Red blood cell distribution width: A simple parameter with multiple clinical applications

The red blood cell distribution width (RDW) is a simple and inexpensive parameter, which reflects the degree of heterogeneity of erythrocyte volume (conventionally known as anisocytosis), and is traditionally used in laboratory hematology for differential diagnosis of anemias. Nonetheless, recent evidence attests that anisocytosis is commonplace in human disorders such as cardiovascular disease, venous thromboembolism, cancer, diabetes, community-acquired pneumonia, chronic obstructive pulmonary disease, liver and kidney failure, as well as in other acute or chronic conditions. Despite some demographic and analytical issues related to the routine assessment that may impair its clinical usefulness, an increased RDW has a high negative predictive value for diagnosing a variety of disorders, but also conveys important information for short- and long-term prognosis. Even more importantly, the value of RDW is now being regarded as a strong and independent risk factor for death in the general population. Although it has not been definitely established whether an increased value of RDW is a risk factor or should only be considered an epiphenomenon of an underlying biological and metabolic imbalance, it seems reasonable to suggest that the assessment of this parameter should be broadened far beyond the differential diagnosis of anemias. An increased RDW mirrors a profound deregulation of erythrocyte homeostasis involving both impaired erythropoiesis and abnormal red blood cell survival, which may be attributed to a variety of underlying metabolic abnormalities such as shortening of telomere length, oxidative stress, inflammation, poor nutritional status, dyslipidemia, hypertension, erythrocyte fragmentation and alteration of erythropoietin function. As such, the aim of this article is to provide general information about RDW and its routine assessment, to review the most relevant implications in health and disease and give some insights about its potential clinical applications.

Alterations in the expression of the NF-κB family member RelB as a novel marker of cardiovascular outcomes during acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) exacerbations are acute events of worsened respiratory symptoms and enhanced inflammation partly mediated by NF-κB activation. RelB, an NF-κB family member, suppresses cigarette smoke-induced inflammation but its expression in COPD is unknown. Moreover, there is no information on its association with clinical features of COPD. The objectives of this study were to assess RelB expression relative to markers of inflammation as well as its association with cardiovascular and pulmonary features of COPD patients at stable-state and exacerbation.

METHODS

Data from 48 COPD patients were analyzed. Blood samples were collected from stable-state and exacerbating patients. After RNA isolation, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to assess RelB, Cox-2, IL-8 and IL-1β mRNA expression and their associations with measured clinical variables.

RESULTS

Of the 48 COPD subjects, 18 were in stable-state and 30 were in exacerbation. RelB mRNA expression was lower than that of Cox-2, IL-8, and IL-1β in all cases (all p<0.001, except for IL-8 at exacerbation (p = 0.22)). Cox-2, IL-8 and IL-1β were significantly associated with clinical features of patients in both stable-state and at exacerbation. There was no association with RelB expression and any clinical features in COPD subjects at stable-state. RelB mRNA levels were significantly associated with cardiovascular events such as systolic blood pressure during exacerbation.

CONCLUSIONS

RelB mRNA expression is lower than that of the other inflammatory mediators. Expression of Cox-2, IL-8 and IL-1β were related to clinical features in both stable-state and at exacerbation. However, RelB expression was associated with clinical features of patients only during exacerbation, suggesting that RelB may represent a novel marker of health outcomes, in particular cardiovascular, during exacerbation in COPD.

Neutrophil-to-lymphocyte ratio in chronic obstructive pulmonary disease: a retrospective study

Chronic obstructive pulmonary disease (COPD) is a common chronic inflammatory disease of the lung with a high mortality and morbidity rate. Some of the inflammatory markers such as C-reactive protein (CRP), leukocyte count are associated with COPD. In this study, we aimed to evaluate the role of neutrophil-to-lymphocyte ratio (NLR) in COPD patients comparing with the other well-known inflammatory markers. We retrospectively enrolled the laboratory results of 269 COPD patients of which 178 patients at stable period and 91 patients during acute exacerbation and 50 sex- and age- matched healthy controls. We found that NLR values of the stable COPD patients were significantly higher than those of the controls (P < 0.001). During acute exacerbation of the disease there was a further increase compared to stable period (P < 0.001). NLR values were also positively correlated with serum CRP levels and red cell distribution width (RDW) and negatively correlated with mean platelet volume (MPV) in both COPD groups. In conclusion, NLR could be considered as a new inflammatory marker for assessment of inflammation in COPD patients with its quick, cheap, easily measurable property with routine complete blood count analysis.

Red cell distribution width is increased in chronic thromboembolic pulmonary hypertension

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening condition characterized by single or recurrent pulmonary embolisms, which promotes pulmonary vascular remodeling. There is significant relationship between red cell distribution width (RDW) and pulmonary hypertension; however, the usefulness of RDW as biomarker for the diagnosis of CTEPH remains poorly defined.

OBJECTIVE

This study sought to assess the change and the diagnostic value of RDW in CTEPH.

METHODS

This retrospective study included 56 CTEPH patients and 56 sex- and age-matched healthy controls treated at Beijing Chao-Yang Hospital. Correlations between RDW and hematological and hemodynamic parameters were assessed. A logistic regression model was applied to test independent parameters in relation to the diagnosis of CTEPH, and receiver operating characteristic curve was plotted to determine the diagnostic value of RDW in CTEPH.

RESULTS

RDW values were significantly higher in CTEPH patients (13.82% ± 1.14%) compared with healthy controls (12.75% ± 0.49%) and in World Health Organization (WHO), functional class III-IV cases (14.39% ± 1.24%) compared with class I-II cases (13.32% ± 0.78%) (both P = 0.000). RDW levels in CTEPH patients showed negative correlations with hemoglobin (r = -0.357, P = 0.007) and cardiac index (r = -0.288, P = 0.031), and positive correlations with pulmonary vascular resistance (r = 0.292, P = 0.029) and WHO functional class (r = 0.450, P = 0.001). Moreover, RDW was an independent parameter in the diagnosis of CTEPH (95% confidence interval: 2.866-13.698, P = 0.000); in particular, an RDW level ≥ 13.05% was the most useful cut-off value, with a sensitivity of 82.1% and a specificity of 71.4%.

CONCLUSION

Increased RDW level may be an acceptable diagnostic parameter for CTEPH.

Acute exacerbation of chronic obstructive pulmonary disease: cardiovascular links

Chronic obstructive pulmonary disease (COPD) is a chronic, progressive lung disease resulting from exposure to cigarette smoke, noxious gases, particulate matter, and air pollutants. COPD is exacerbated by acute inflammatory insults such as lung infections (viral and bacterial) and air pollutants which further accelerate the steady decline in lung function. The chronic inflammatory process in the lung contributes to the extrapulmonary manifestations of COPD which are predominantly cardiovascular in nature. Here we review the significant burden of cardiovascular disease in COPD and discuss the clinical and pathological links between acute exacerbations of COPD and cardiovascular disease.

Red cell distribution width is associated with long-term prognosis in patients with stable coronary artery disease

Background

Data regarding the association between red cell distribution width (RDW) values and mortality in patients with stable coronary artery disease are scarce. We aimed to investigate the link between mortality and RDW in patients with stable coronary artery disease undergoing percutaneous coronary intervention (PCI).

Methods

We analyzed 2550 consecutive patients with stable coronary artery disease who underwent PCI between 2007 and 2011 at our institution. The patients were divided into four groups according to RDW quartiles. The association between the RDW values and the outcomes was assessed using Cox proportional regression analysis after adjusting for clinical, echocardiographic, hemodynamic and laboratory data in the whole population and in subgroups stratified by gender, presence of diabetes, anemia or heart failure.

Results

In the entire population, there was a stepwise relationship between RDW intervals and comorbidities. Patients with the highest RDW values were older and more often burdened with diabetes, heart failure and chronic kidney disease. There was an almost 4-fold increase in mortality during an average of 2.5 years of follow-up between the group of patients with RDW values lower than 13.1% (25^th percentile) and the group with RDW values higher than 14.1% (75^th percentile), (4.3% vs. 17.1%, p < 0.0001). After adjusting for the covariates, RDW remained significantly associated with mortality in the whole cohort (HR-1.23 [95% CI (1.13-1.35), p < 0.0001]) and in the subgroups stratified by gender, age (over and under 75 years), presence of anemia, diabetes, heart failure and chronic kidney disease.

Conclusion

Higher RDW values correspond to higher comorbidity burdens and higher mortality. RDW is an independent predictor of mortality in patients with stable coronary artery disease.

The red cell distribution width as a sensitive biomarker for assessing the pulmonary function in automobile welders- a cross sectional study

CONTEXT

Welding fumes are considered as a risk factor for pulmonary diseases and a periodic spirometry is essential to evaluate the lung function of the welders. The Red Cell Distribution Width (RDW) is a red cell measurement which is provided by automated haematology analyzers. It reflects the range of the red cell sizes which are measured within a sample. Few studies have shown a relationship between the RDW values and the changes in the spirometry.

AIMS

This study was aimed at correlating the RDW% and the spirometry FEV1/FVC ratio (%) among automobile welders (cases). Further, we have analyzed the effect of smoking on the FEV1/FVC ratio% and the RDW% in the cases.

SETTINGS AND DESIGN

A cross sectional study was done on 50 welders and 50 non-welding office workers (controls) who were working in an automobile industry on the outskirts of Chennai, india. All the cases were arc welders and the controls were from the same production unit, who had never worked as welders. This study was conducted during the period from March 2012 to May 2012.

METHODS AND MATERIAL

The demographic data, smoking habits, work history and the respiratory symptoms were gathered by using a standard self -administered questionnaire. A complete haemogram study was done and pulmonary function tests were performed for both the cases and the controls. All the cases and the controls were examined in the hospital outpatients room and subsequently, their blood samples were collected. The pulmonary function tests were conducted in the spirometry room in the hospital. The statistical analysis was done using the SPSS, version 15.0.

RESULTS

A statistically significant inverse correlation was found between the RDW% and the FEV1/FVC ratio% in the cases.

CONCLUSIONS

RDW can be used as a biomarker to identify the pulmonary compromise in automobile welders.