Red blood cell distribution width is significantly associated with aging and gender

Deformability of Heterogeneous Red Blood Cells in Aging and Related Pathologies

Aging is interrelated with changes in red blood cell parameters and functionality. In this article, we focus on red blood cells (RBCs) and provide a review of the known changes associated with the characterization of RBC deformability in aging and related pathologies. The biophysical parameters complement the commonly used biochemical parameters and may contribute to a better understanding of the aging process. The power of the deformability measurement approach is well established in clinical settings. Measuring RBCs' deformability has the advantage of relative simplicity, and it reflects the complex effects developing in erythrocytes during aging. However, aging and related pathological conditions also promote heterogeneity of RBC features and have a certain impact on the variance in erythrocyte cell properties. The possible applications of deformability as an early biophysical biomarker of pathological states are discussed, and modulating PIEZO1 as a therapeutic target is suggested. The changes in RBCs' shape can serve as a proxy for deformability evaluation, leveraging single-cell analysis with imaging flow cytometry and artificial intelligence algorithms. The characterization of biophysical parameters of RBCs is in progress in humans and will provide a better understanding of the complex dynamics of aging.

Evaluation of CSF 8-iso-prostaglandin F2α and erythrocyte anisocytosis as prognostic biomarkers for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Delayed cerebral ischemia (DCI) is a serious, life-threatening, complication affecting patients who have survived the initial bleeding from a ruptured intracranial aneurysm. Due to the challenging diagnosis, potential DCI prognostic markers should be of value in clinical practice. According to recent reports isoprostanes and red blood cell distribution (RDW) showed to be promising in this respect. We conducted a prospective study of 27 aSAH patients and control group (n = 8). All patients from the study group were treated within the first day of the initial bleeding. We collected data regarding clinical status and results of biochemical, and radiological examinations. We measured cerebrospinal fluid (CSF) concentration of 8-iso-prostaglandin F2α (F2-IsoP) and RDW on days 1, 3, and 5. Both CSF F2-IsoP level and RDW-SD measured on day 1 were significant predictors of DCI. The receiver operating characteristics curve for DCI prediction based on the multivariate model yielded an area under the curve of 0.924 (95% CI 0.824-1.000, p < 0.001). In our study, the model based on the combination of RDW and the level of isoprostanes in CSF on the first day after the initial bleeding showed a prognostic value for DCI prediction. Further studies are required to validate this observation.

Red Cell Distribution Width as a Predictive Factor of Celiac Disease in Middle and Late Adulthood and Its Potential Utility as Celiac Disease Screening Criterion

Red cell distribution width (RDW) could be of interest by its potential use in the assessment of celiac disorder (CD). The main objective of this study was to evaluate the case positive rate of CD and the utility of red cell distribution width (RDW) in the CD diagnosis. This prospective study included 9.066 middle adult (≥45 years old) and elderly patients (≥60 years old) from 2012 to 2021. CD diagnosis was performed by CD antibody tests (serology and Human Leucocyte Antigen genotype (HLA)) and biopsy. Gastrointestinal and extra-intestinal manifestations as well as hematological and biochemical parameters were analyzed. CD diagnoses were confirmed in 101 patients (median (IQR) age = 62 (52.3−73); 68.32% women) by serologic tests (100%) and intestinal biopsy (88.12%), showing mainly marked or complete atrophy (76.24%, MARSH 3a−c). Anemia was the most commonly presenting extra-intestinal manifestation (28.57%). Among 8975 individuals without CD, 168 age and sex matched were included. By comparison of CD and no CD individuals, we observed that high >14.3% RDW was exhibited by 58.40% and 35.2% individuals with CD and without CD, respectively. Furthermore, high RDW is associated with CD and grade III atrophy. We suggest that RDW could be used as a CD screening criterion.

Prognostic Value of Red Blood Cell Distribution Width (RDW) in the Recurrence of Hepatocellular Carcinoma Following Curative Resection

Purpose

Although surgery is associated with an acceptable cure rate, tumor recurrence is still a challenging issue in hepatocellular carcinoma (HCC) patients. Red blood cell distribution width (RDW) is considered an inflammatory marker for predicting overall mortality in a wide spectrum of malignancies. In the current study, the prognostic role of pre- and postoperative RDW in HCC recurrence after liver resection (LRx) is investigated.

Patients and Methods

In 395 patients, RDW levels were evaluated preoperatively as well as six and twelve months after curative LRx. The RDW cutoff values were determined using receiver operating characteristic curves (ROCs) according to the recurrence-free survival (RFS). Survival analyses were performed using the Kaplan-Meier, and differences were compared using the Log rank test.

Results

The RFS was significantly higher among patients with low RDW at the 6th month and 12th month, postoperatively (P < 0.001 and P = 0.028). RDW levels of higher than 16.15% at the 6th (HR: 2.047, P <0.001) and higher than 15.85% at 12th (HR: 3.105, P < 0.002) months after liver resection were independent predictors of RFS.

Conclusion

Postoperative RDW values seem to be predictive of tumor recurrence in HCC patients. RDW levels at the 6th and 12th months postoperatively were independent predictors of recurrence after LRx.

Recent advances in laboratory hematology reflected by a decade of CCLM publications

On the occasion of the 60th anniversary of Clinical Chemistry and Laboratory Medicine (CCLM) we present a review of recent developments in the discipline of laboratory hematology as these are reflected by papers published in CCLM in the period 2012–2022. Since data on CCLM publications from 1963 to 2012 are also available, we were able to make a comparison between the two periods. This interestingly revealed that the share of laboratory hematology papers has steadily increased and reached now 16% of all papers published in CCLM. It also became evident that blood coagulation and fibrinolysis, erythrocytes, platelets and instrument and method evaluation constituted the ‘hottest’ topics with regard to number of publications. Some traditional, characteristic CCLM categories like reference intervals, standardization and harmonization, were more stable and probably will remain so in the future. With the advent of important newer topics, like new coagulation assays and drugs and cell population data generated by hematology analyzers, laboratory hematology is anticipated to remain a significant discipline in CCLM publications.

The effect of SGLT-2i administration on red blood cell distribution width in patients with heart failure and type 2 diabetes mellitus: A randomized study

Background

Recent studies suggest that the pivotal mechanism of sodium glucose co-transporter-2 inhibitors (SGLT-2i) favorable action in patients with heart failure (HF) and type 2 diabetes mellitus (DM) is the stimulation of erythropoiesis via an early increase in erythropoietin (EPO) production which leads to hematocrit rise. Red blood cell distribution width (RDW) is a simple hematological parameter which reflects the heterogeneity of the red blood cell size (anisocytosis). Since, EPO has been also implicated in the pathophysiology of RDW increase, the current mechanistic study examined the effect of SGLT-2i administration on red blood cells size (RDW) in patients with HF and DM.

Methods

The present was a prospective single-center study. Patients (N=110) were randomly assigned to dapagliflozin (10 mg a day on top of antidiabetic treatment) or the control group. Inclusion criteria were: (a) age > 18 years, (b) history of type 2 DM and hospitalization for HF exacerbation within 6 months. The evaluation of patients (at baseline, 6 and 12 months) included clinical assessment, laboratory blood tests, and echocardiography. Data were modeled using mixed linear models with dependent variable the RDW index. In order to find factors independently associated with prognosis (1-year death or HF rehospitalization), multiple logistic regression was conducted with death or HF rehospitalization as dependent variable.

Results

An RDW increase both after 6 and after 12 months was observed in the SGLT-2i (dapagliflozin) group (p < 0.001 for all time comparisons), whereas RDW didn't change significantly in the control group. The increase in RDW was positively correlated with EPO, while negatively correlated with ferritin and folic acid (p < 0.005 for all). Baseline RDW was significantly associated with 1-year death or rehospitalization, after adjusting for group (SGLT-2i vs. control), age, gender, smoking and BMI at baseline.

Conclusion

RDW increased with time in patients with HF and DM who received SGLT-2i (dapagliflozin). The increased RDW rates in these patients may stem from the induction of hemopoiesis from dapagliflozin. Baseline RDW was found to be independently associated with outcome in patients with HF and DM.

Red blood cell distribution width to predict mortality in heart transplant recipients: a systematic review

Red blood cell distribution width (RDW) has been shown to have prognostic value in a number of different clinical settings, such as cardiovascular disease, including heart failure. However, its prognostic value in heart transplant (HT) recipients remains unknown. The aim of this systematic review is to determine the prognostic value of pre-transplant RDW for mortality in HT recipients. There is a pre-published protocol of this review. The terms "Heart transplant", "Red cell distribution width" and their synonyms were used in the search strategy. PubMed/Medline, Embase, Scopus, Web of Science and LILACS were searched until May 17th, 2022, without date or language restrictions. Two authors independently carried out the selection, first by title and abstract, second by full-text revision. Discrepancies were discussed and resolved with three other authors. Quality of individual studies was assessed with Newcastle Ottawa Scale (NOS) for cohorts. After removing the duplicates, 3885 articles were identified. Four articles were included in the qualitative synthesis. Three studies were classified as “good quality”: whereas one as “poor quality” according to NOS scale. All the included articles evaluated long-term mortality and one study also evaluated short-term mortality. In this one, a correlation between higher RDW values and short-term mortality was reported. Meanwhile, in all the studies, a high pre-HT RDW was a marker of long-term mortality following cardiac transplantation. Our review shows that an elevated on-admission RDW is associated with long-term mortality in heart transplantation recipients.

Succinate dehydrogenase inversely regulates red cell distribution width and healthy lifespan in chronically hypoxic mice

Increased red cell distribution width (RDW), which measures erythrocyte volume (MCV) variability (anisocytosis), has been linked to early mortality in many diseases and in older adults through unknown mechanisms. Hypoxic stress has been proposed as a potential mechanism. However, experimental models to investigate the link between increased RDW and reduced survival are lacking. Here, we show that lifelong hypobaric hypoxia (~10% O2) increases erythrocyte numbers, hemoglobin and RDW, while reducing longevity in male mice. Compound heterozygous knockout (chKO) mutations in succinate dehydrogenase (Sdh; mitochondrial complex II) genes Sdhb, Sdhc and Sdhd reduce Sdh subunit protein levels, RDW, and increase healthy lifespan compared to wild-type (WT) mice in chronic hypoxia. RDW-SD, a direct measure of MCV variability, and the standard deviation of MCV (1SD-RDW) show the most statistically significant reductions in Sdh hKO mice. Tissue metabolomic profiling of 147 common metabolites shows the largest increase in succinate with elevated succinate to fumarate and succinate to oxoglutarate (2-ketoglutarate) ratios in Sdh hKO mice. These results demonstrate that mitochondrial complex II level is an underlying determinant of both RDW and healthy lifespan in hypoxia, and suggest that therapeutic targeting of Sdh might reduce high RDW-associated clinical mortality in hypoxic diseases.

Role of red cell dstribution width in colorectal cancer diagnosis and prognosis

Objective: We aimed to assess whether red cell distribution width (RDW) was associated with pre-operative clinical features or post-operative clinicopathological outcomes in patients with colorectal cancer (CRC), and to determine the utility of RDW as a diagnostic or prognostic marker of CRC. Material and Method: This retrospective cohort study was conducted between January 2018 and May 2021 at a university hospital in Turkey. A total of 188 patients histologically diagnosed with CRC who had undergone surgery were included in the study. Results: Our study included 118 (62.77%) male patients, and the mean age of the patients was 66.28±11.71 years. We found that RDW values were significantly higher in females compared to males (p=0.033), in patients with T3 or T4 tumors compared to those with T1 or T2 tumors (p

Red Blood Cell Distribution Width in Hospitalized COVID-19 Patients

Introduction: Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is causing dramatic morbidity and mortality worldwide. The Red Blood Cell Distribution Width (RDW) has been strongly associated with increased morbidity and mortality in multiple diseases.

Objective: To assess if elevated RDW is associated with unfavorable outcomes in hospitalized COVID-19.

Methods: We retrospectively studied clinical outcomes of hospitalized COVID-19 patients for their RDW values. In-hospital mortality was defined as primary outcome, while septic shock, need for mechanical ventilation, and length of stay (LOS) were secondary outcomes.

Results: A total of 294 COVID-19 patients were finally studied. Overall prevalence of increased RDW was 49.7% (146/294). RDW was associated with increased risk of in-hospital mortality (aOR, 4.6; 95%CI, 1.5-14.6) and septic shock (aOR, 4.6; 95%CI, 1.4-15.1) after adjusting for anemia, ferritin, lactate, and absolute lymphocyte count. The association remained unchanged even after adjusting for other clinical confounders such as age, sex, body mass index, coronary artery disease, hypertension, diabetes mellitus, and chronic obstructive pulmonary disease. No association was found instead with mechanical ventilation and median LOS.

Conclusion: Elevated RDW in hospitalized COVID-19 patients is associated with a significantly increased risk of mortality and septic shock.

Prognostic value of red blood cell distribution width in predicting 3-month functional outcome of patients undergoing thrombolysis treatment for acute ischemic stroke

This study was performed to determine whether red blood cell distribution width (RDW) is associated with 3-month poor functional outcome in patients undergoing thrombolytic therapy for acute ischemic stroke.RDW was measured in patients with thrombolytic therapy in emergency department. Functional outcome was assessed after 3 months and poor functional outcome was defined as modified Rankin scale 3 to 6.A total of 240 patients were enrolled, and 82 (34.2%) had a poor functional outcome. The median RDW was significantly elevated in patients with a poor functional outcome compare with those with a good outcome. RDW was independently associated with a 3-month poor functional outcome (odds ratio 3.369, 95% confidence interval 2.214-5.125). The optimal RDW cutoff for predicting 3-month poor functional outcome was 12.8%, and the area under the curve for RDW was 0.818 (95% confidence interval 0.761-0.876). The area under the curve for RDW was higher in male patients than in female patients. The RDW correlated positively with the modified Rankin scale score after 3 months and the initial National Institutes of Health Stroke Scale score.Initial higher RDW level is related to a 3-month poor functional outcome in patients undergoing thrombolytic therapy for acute ischemic stroke.

Longitudinal analysis of blood markers reveals progressive loss of resilience and predicts human lifespan limit

We investigated the dynamic properties of the organism state fluctuations along individual aging trajectories in a large longitudinal database of CBC measurements from a consumer diagnostics laboratory. To simplify the analysis, we used a log-linear mortality estimate from the CBC variables as a single quantitative measure of the aging process, henceforth referred to as dynamic organism state indicator (DOSI). We observed, that the age-dependent population DOSI distribution broadening could be explained by a progressive loss of physiological resilience measured by the DOSI auto-correlation time. Extrapolation of this trend suggested that DOSI recovery time and variance would simultaneously diverge at a critical point of 120 - 150 years of age corresponding to a complete loss of resilience. The observation was immediately confirmed by the independent analysis of correlation properties of intraday physical activity levels fluctuations collected by wearable devices. We conclude that the criticality resulting in the end of life is an intrinsic biological property of an organism that is independent of stress factors and signifies a fundamental or absolute limit of human lifespan.

Biomarkers of Senescence during Aging as Possible Warnings to Use Preventive Measures

Human life expectancy is increasing significantly over time thanks to the improved possibility for people to take care of themselves and the higher availability of food, drugs, hygiene, services, and assistance. The increase in the average age of the population worldwide is, however, becoming a real concern, since aging is associated with the rapid increase in chronic inflammatory pathologies and degenerative diseases, very frequently dependent on senescent phenomena that occur alongside with senescence. Therefore, the search for reliable biomarkers that can diagnose the possible onset or predict the risk of developing a disease associated with aging is a crucial target of current medicine. In this review, we construct a synopsis of the main addressable biomarkers to study the development of aging and the associated ailments.

Red cell distribution width and erythrocyte osmotic stability in type 2 diabetes mellitus

This study aimed to investigate the relationship between red cell distribution width (RDW) and erythrocyte osmotic stability in non‐diabetic and diabetic individuals in both sexes. The study sample (N = 122) was constituted by 53 type 2 diabetics (DM) and 69 non‐diabetics (ND), being 21 and 22 men in each group, respectively. The osmotic stability of erythrocytes was obtained by the variation in saline concentration (dX) capable of determining hypoosmotic lysis. Higher RDW values and lower serum iron concentrations were found in the diabetic group when compared to the non‐diabetic volunteers. In the group of diabetic women, RDW was positively correlated with the reticulocyte index, and both RDW and dX were negatively correlated with iron, haemoglobin, transferrin saturation index, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. In all the groups studied, RDW was positively correlated with dX, especially in the diabetic group, where the correlation was the strongest. RDW elevation in both women and men with type 2 diabetes mellitus was associated with decreased serum iron indicators. Furthermore, RDW has a similar meaning to dX, as small erythrocytes have less haemoglobin, resulting in both an increase of RDW and dX.

Sex-related aspects of the red blood cell storage lesion

BACKGROUND

Several factors contribute to the manifestation of red blood cell (RBC) storage lesions, with one of the most interesting being the "donor variation effect". Since many haematological characteristics of blood donors are sex-dependent, sex hormones and their age-dependent variation may affect the storage profile of RBCs.

MATERIALS AND METHODS

Fresh blood from 200 healthy male and female donors underwent haematological, biochemical and physiological analysis. Three selected groups of donors (men, n=8; pre-menopausal women, n=8; and post-menopausal women, n=4) exhibiting as similar as possible baseline values were recruited for blood donation in leukoreduced CPD/SAGM units. RBC indices, haemolysis and propensity for haemolysis, reactive oxygen species (ROS) and plasma antioxidant capacity were measured bi-weekly.

RESULTS

Female blood was characterised by lower plasma antioxidant capacity and free haemoglobin (Hb) levels in vivo, in spite of the higher RBC osmotic fragility, compared to male blood. Comparatively low Hb concentration was also measured in stored RBCs from female donors, as in vivo. Mean corpuscular Hb (MCH), mean corpuscular Hb concentration (MCHC), and plasma antioxidant capacity were also lower in female donors throughout storage, even though baseline levels were equal to those of the male group. There was no difference in propensity of stored RBCs for haemolysis between male and female units but intracellular ROS levels were significantly lower in female RBCs. Increased end-of-storage extracellular potassium and recruitment of protein stress markers (clusterin, Hb) to the RBC membrane were observed in the units of post- vs pre-menopausal female donors at mid-storage onwards.

DISCUSSION

Donor's sex has an impact on Hb concentration and redox parameters of stored RBCs. In addition, menopause seems to promote RBC membrane remodelling, at least during prolonged storage. Our pilot study provides new insights on the different effects on RBC storage lesion according to sex.

Red Cell Distribution Width as a Novel Prognostic Marker in Multiple Clinical Studies

Red cell distribution width (RDW), which is a quantitative method applied for the measurement of anisocytosis, is the most reliable and inexpensive method for differentiation of iron deficiency anemia and thalassemia trait. An increase in its rate reflects a great heterogeneity in the size of red blood cells (RBCs). Recent studies have shown a significant relationship between RDW and the risk of morbidity and mortality in patients with multiple diseases. A strong association is established between changes in RDW and the risk of adverse outcome in patients with heart failure in multiple studies. In this review, we try to focus on the association and correlation between the increase in RDW and different outcomes of common diseases that may be related to RDW and based on the results of various studies, we are trying to introduce RDW as a diagnostic indicator for these diseases.

Baseline Red Blood Cell Distribution Width as a Predictor of Stroke Occurrence and Outcome: A Comprehensive Meta-Analysis of 31 Studies

Background: Red blood cell distribution width (RDW) may be a potential biomarker of inflammation in patients with stroke. Elevated RDW is associated with higher incidence of stroke, unfavorable functional outcome, and increased mortality, although results are inconsistent in the reported literature. This study aims to evaluate the predictive power of RDW regarding stroke occurrence and outcome. Methods: A thorough literature search was conducted utilizing the PubMed Central (PMC) and EMBASE databases to identify studies up to May 2019. Data from these studies were pooled, and combined odds ratios/risk ratios (ORs/RRs) were estimated for the risk of stroke, functional outcome, and mortality. A subgroup analysis was also performed to explore heterogeneity in terms of population status, demographic factors (age, gender distribution, and country), and vascular risk factors (hypertension, diabetes mellitus, and current smoking). Results: A total of 31 studies with 3,487,896 patients were included in the analysis. Elevated RDW was found to be a risk factor in ischemic stroke (OR/RR 1.528; 95% confidence interval [CI] = 1.372-1.703), whereas combined OR in subarachnoid hemorrhage (SAH) was not statistically significant (OR/RR 1.835; 95% CI = 0.888-3.792). Elevated RDW posed increased risk in populations with conventionally higher risk of stroke, such as atrial fibrillation (AF) (OR/RR 1.292; 95% CI = 1.107-1.508) and diabetes mellitus (OR/RR 2.101; 95% CI = 1.488-2.968), and in community cohorts (OR/RR 1.245; 95% CI = 1.216-1.275). In addition, higher RDW was associated with unfavorable functional outcome, either at discharge (OR/RR 1.220; 95% CI = 1.070-1.39) or at 90 days (OR/RR 1.277; 95% CI = 1.155-1.413). Higher mortality was found in patients with increased RDW (OR/RR 1.278; 95% CI = 1.221-1.337), independent of demographic factors (age, gender distribution, and country). Conclusions: Baseline RDW should be integrated into clinical practice as a predictor of ischemic stroke occurrence and outcome. Future studies should also explore the dynamic change of RDW in post-stroke patients to evaluate the clinical significance of RDW and its impact on the inflammatory state of ischemic stroke.

The role of red blood cell distribution width (RDW) in cardiovascular risk assessment: useful or hype?

Red blood cell distribution width (RDW) reflects erythrocyte size distribution, thus representing a reliable index of anisocytosis, widely used for the differential diagnosis of micro- and normocytic anaemias. Along with the large use in diagnostic hematology, RDW has been associated with presence and complications of a vast array of human pathologies during the last decades, including cardiovascular (CV) diseases. This article is hence aimed to provide an overview of important studies and systematic reviews with meta-analysis, in which RDW has been associated with CV events and mortality, in the attempt of establishing whether enough evidence exists for supporting its routine use in clinical practice. According to available data it seems reasonable to conclude that although the diagnostic specificity is low, and this measure is still plagued by important lack of standardization, RDW can be regarded as an index of enhanced patient fragility and higher vulnerability to adverse outcomes. Abnormal RDW values shall hence persuade physicians to broaden the diagnostic reasoning over anaemias, especially those due to malnutrition or malabsorption, encompassing a comprehensive assessment of traditional and non-traditional CV risk factors.

Prognostic role of pretreatment red blood cell distribution width in patients with cancer: A meta-analysis of 49 studies

Red blood cell distribution width (RDW) has been recently demonstrated to be a predictor of inflammation. High pretreatment RDW level is associated with poor survival outcomes in various malignancies, although the results are controversial. We aimed to investigate the prognostic role of RDW. A systematic literature search was performed in MEDLINE and EMBASE till April 2018. Pooled hazard ratios (HRs) were estimated for overall survival (OS) and combined disease-free survival, progression-free survival, and recurrence-free survival (DFS/PFS/RFS). 49 studies with 19,790 individuals were included in the final analysis. High RDW level adversely affected both OS and DFS/PFS/RFS. For solid cancers, colorectal cancer (CRC) had the strongest relationship with poor OS, followed by hepatic cancer (HCC). Negative OS outcomes were also observed in hematological malignancies. Furthermore, patients at either early or advanced stage had inverse relationship between high pretreatment RDW and poor OS. Studies with cut-off values between 13% and 14% had worse HRs for OS and DFS/PFS/RFS than others. Furthermore, region under the curve (ROC) analysis was used widely to define cut-off values and had relatively closer relationship with poorer HRs. In conclusion, our results suggested that elevated pretreatment RDW level could be a negative predictor for cancer prognosis.

Red blood cell distribution width in pregnancy: a systematic review

Anisocytosis has been associated with the severity and prognosis of several acute and chronic diseases, as well as physiological conditions such as pregnancy. Anisocytosis is quantified by the red blood cell distribution width (RDW), expressed as the ratio, multiplied by 100, between the standard deviation (SD) of red blood cell volumes and the mean corpuscular volume, or as the SD of erythrocyte volumes (RDW-SD). The aim of the present review was to report the state of the art on the physiological values and the putative diagnostic and prognostic roles of RDW in complicated pregnancy. Literature research for articles published in the last ten years was conducted in Pubmed, Web of Science, ClinicalTrials.gov, and Scopus databases. Abstracts were independently screened by two investigators. If relevant, full articles were retrieved. References, in these articles, citing relevant reviews or original studies were also accessed to identify additional eligible studies. Any disagreement between the reviewers was resolved by a third investigator. A total of 28 studies were included in the review. These studies reported changes in RDW values during physiological pregnancy, and associations between the RDW and several pregnancy complications including anaemia, preeclampsia, gestational diabetes, and recurrent miscarriage. This review provides background information for establishing physiological and pathological RDW values in pregnancy for diagnostic and prognostic use in clinical practice.

Elevated red cell distribution width to platelet count ratio predicts poor prognosis in patients with breast cancer

Red cell distribution width (RDW) to platelet ratio (RPR) is a prognosticator in acute pancreatitis and myocardial infarction; however, the prognostic values of RDW and RPR in breast cancer have not been studied. This retrospective analysis of 299 breast cancer patients investigated the association between RDW and RPR and clinicopathological characteristics and prognosis, compared to platelet distribution width to platelet count ratio (PDW/P) which is a known independent prognostic factor in patients with breast cancer. We found a significant correlation between RPR, and age and HER2 status. An elevated RPR significantly correlated with age and HER2 status. After a median follow-up duration of 48 months, tumour size, nuclear grade, PDW/P, and RPR were recgnized to be significantly associated with lower disease-free survival rates (tumour size: p < 0.01; nuclear grade, PDW/P, and RPR: p < 0.05) in univariate analysis. Tumour size and RPR were significant prognostic factors for lower disease-free survival rates, with hazard ratios of 4.31 (95% confidence interval: 1.76–10.53) (p < 0.01)] and 2.79 [95% confidence interval: 1.01–87.69) (p < 0.05)], respectively, in a multivariate analysis using the Cox proportional hazards model. This is the first study showing that an elevated RPR could independently predict poor prognosis in patients with breast carcinoma. Thus, RPR could be a novel biomarker for prognostic estimation.

Hip fracture patients who experience a greater fluctuation in RDW during hospital course are at heightened risk for all-cause mortality: a prospective study with 2-year follow-up

This study aims to detect whether there remains valuable prognostic information in fluctuation of red cell distribution width (RDW) in hip fracture patients. Results show that this readily available parameter may provide a more effective strategy for assessment of mortality risk, therefore providing a reference for clinical planning and decision-making.

INTRODUCTION

Prognostic values have been found in the fluctuation of some hematologic parameters. The red cell distribution width (RDW) routinely reported with all complete blood cell counts (CBC) has proven to be associated with poor outcomes in various diseases. However, whether the fluctuation in RDW is predictive of long-term mortality in hip fracture patients treated with surgery remains unknown.

METHODS

One thousand three hundred thirty hip fracture patients who underwent surgery from January 1, 2000 to November 18, 2012 were recruited in this prospective cohort study. Fluctuation in the RDW between admission and discharge was measured, and a Kaplan-Meier (KM) analysis and multivariable Cox regression model were applied to evaluate the relationship between this fluctuation and mortality. Risk factors for a larger fluctuation were detected by using Logistic regression analyses.

RESULTS

In addition to the admission RDW, a high RDW level at the time of discharge was also associated with an increased risk of death, while no significant difference was found in the postoperative RDW. Fluctuation in the RDW between admission and discharge was an independent risk predictor for 2-year mortality (HR 1.45 95%CI 1.06-2.00, p = 0.022). Factors affecting the change in the RDW between admission and discharge included both the demographic characteristics of the patients and clinical interventions.

CONCLUSION

Hip fracture patients who experience a greater fluctuation in RDW during the hospital course are at a heightened risk for 2-year all-cause mortality.

High red cell distribution width at the time of ST segment elevation myocardial infarction is better at predicting diastolic than systolic left ventricular dysfunction: A single-center prospective cohort study

Multiple studies have demonstrated the association of red cell distribution width (RDW) with the ultrasound parameters of both systolic and diastolic heart dysfunction. We aimed to further investigate the clinical associations of RDW in the setting of ST-elevation myocardial infarction (STEMI) and to comparatively evaluate its predictive properties regarding systolic and diastolic dysfunction.A total of 89 patients with STEMI were prospectively analyzed. RDW was obtained at the time of STEMI and compared to the parameters of systolic and diastolic dysfunction obtained by transthoracic heart ultrasound on the 5th through 7th day post-STEMI.The median RDW was 13.9%, and among other factors, RDW was significantly associated with older age (P < .001), arterial hypertension (P = .017), hyperlipoproteinemia 2, nonsmoking (P = .027), increased thrombolysis in myocardial infarction score (P = .004), and multivessel disease (P = .007). A higher RDW was observed in patients with parameters that indicated systolic and diastolic dysfunction (ejection fraction of the left ventricle < 50% [P = .009], early/late diastolic filling wave ratio [E/A] < 1 [P = .001], ratio of peak early transmitral velocity and early diastolic annular velocity [E/E'] >10 [P < .001], and combined E/A < 1 and E/E' > 10 [P < .001]). The best discriminatory properties were observed for combined E/A < 1 and E/E' > 10. RDW remained significantly associated with the aforementioned parameters in a series of multivariate regression models.Elevated RDW is significantly associated with the parameters of systolic and diastolic dysfunction even after adjusting for several confounding factors in the setting of STEMI and subsequent percutaneous coronary intervention. RDW seems to be better at discriminating patients with diastolic rather than systolic dysfunction.

Red blood cell distribution width in heart failure: A narrative review

The red blood cell distribution width (RDW) is a simple, rapid, inexpensive and straightforward hematological parameter, reflecting the degree of anisocytosis in vivo. The currently available scientific evidence suggests that RDW assessment not only predicts the risk of adverse outcomes (cardiovascular and all-cause mortality, hospitalization for acute decompensation or worsened left ventricular function) in patients with acute and chronic heart failure (HF), but is also a significant and independent predictor of developing HF in patients free of this condition. Regarding the biological interplay between impaired hematopoiesis and cardiac dysfunction, many of the different conditions associated with increased heterogeneity of erythrocyte volume (i.e., ageing, inflammation, oxidative stress, nutritional deficiencies and impaired renal function), may be concomitantly present in patients with HF, whilst anisocytosis may also directly contribute to the development and worsening of HF. In conclusion, the longitudinal assessment of RDW changes over time may be considered an efficient measure to help predicting the risk of both development and progression of HF.

Prognostic value of admission red blood cell distribution width in acute pancreatitis: a systematic review

BACKGROUND

Red blood cell distribution width (RDW) has been proved to be a strong prognostic marker in various diseases such as cardiovascular diseases, renal failure, viral hepatitis etc. But its prognostic value in acute pancreatitis (AP) remains controversial. The aim of this systematic review is to determine the prognostic value of RDW in AP.

METHODS

PubMed, Cochrane, Google scholar, and Web of Science were searched on March 2, 2017 to identify studies that investigated the association between RDW and the prognosis of AP. The eligible studies were reviewed and summarized.

RESULTS

In total, 2008 articles were screened. Seven studies were included in the final analysis. Five studies estimated the prognostic value of RDW using receiver operating characteristic (ROC) curve analysis, and multivariable analysis was performed in only four studies. The major design weaknesses of eligible studies are their retrospective design and some of potential confounding factors were not adjusted.

CONCLUSIONS

Current evidence and findings support that high admission RDW can be used as a biomarker to identify the AP patients who are at high risk of mortality. However, due to the weaknesses of available studies, further well-designed studies with large sample size and various outcome endpoints are needed to rigorously evaluate the prognostic value of RDW in AP.

Prognostic significance of red blood cell distribution width in gastrointestinal disorders

The red blood cell distribution width (RDW) is a routinely measured and automatically reported blood parameter, which reflects the degree of anisocytosis. Recently, the baseline RDW was found to have clinical significance for assessing clinical outcome and severity of various pathological conditions including cardiovascular diseases, sepsis, cancers, leukemia, renal dysfunction and respiratory diseases. A myriad of factors, most of which ill-defined, have an impact on the red cell population dynamics (i.e., production, maturation and turnover). A delay in the red blood cell clearance in pathological conditions represents one of the leading determinants of increased anisocytosis. Further study of RDW may reveal new insight into inflammation mechanisms. In this review, we specifically discuss the current literature about the association of RDW in various disease conditions involving the gastrointestinal and hepatobiliary systems. We also present some of the related measurements for their value in predicting clinical outcomes in such conditions. According to our data, RDW was found to be a valuable prognostic index in gastrointestinal disorders along with additional inflammatory biomarkers (i.e., C reactive protein, erythrocyte sedimentation rate, and platelet count) and current disease severity indices used in clinical practice.

Red blood cell distribution width and carotid intima-media thickness in patients with metabolic syndrome

Background

To evaluate the relationship between red blood cell distribution width (RDW) and carotid intima-media thickness (CIMT) in metabolic syndrome (MetS) patients.

Methods

In this study, we analyzed 803 patients with MetS who underwent carotid ultrasonography examination at Henan Province Hospital of Traditional Chinese Medicine from October 2014 to September 2015. Demographic data were collected using a questionnaire. An automatic biochemistry analyzer measured RDW. Pearson correlation coefficient, multivariate linear and logistic regression was used to evaluate the correlation between RDW and CIMT.

Results

Compared with control group, case group had higher RDW level (P  < 0.001) and CIMT (P  < 0.001). CIMT was positively related to RDW (r  = 0.436, P  < 0.001). Logistic regression indicated that RDW was a predictor of CIMT ≥ 1 mm. Compared with the first quartile, people with third and fourth quartile level gave obvious higher risk of carotid artery atherosclerotic trend (OR = 1.41, 95% CI:1.01–197; OR = 2.10, 95% CI: 1.30–3.40). Using a cutoff point of 13.9%, RDW predicts elevated CIMT with a sensitivity of 62.1% and a specificity of 70.3%.

Conclusion

High RDW is related to the increased CIMT in MetS patients, which highlights the role of RDW in the progression of elevated CIMT in MetS patients.

Importance of Mean Red Cell Distribution Width in Hypertensive Patients

PURPOSE

Red cell distribution width (RDW), expressed in femtoliters (fl), is a measure of the variation in the size of circulating erythrocytes and is often expressed as a direct measurement of the width of the distribution. We aim to observe the mean value of red cell distribution width (RDW) in hypertensive patients. Increased RDW can be used as a tool for early diagnosis, as an inflammatory marker, and a mortality indicator in hypertensive patients due to its close relation to inflammation.

MATERIALS AND METHODOLOGY

Hypertensive patients who had the condition for more than one year duration, diagnosed according to the Joint National Committee (JNC 7) criteria were subjected to complete blood count and RDW measurement. One hundred patients, aged between 12 years and 65 years were enrolled from the outpatient department of medicine at the Military Hospital Rawalpindi.

RESULTS

The mean age (± SD) of the patients was 51.48 ± 10.08 years. Out of 100 patients 69% were males whereas 31% were females. The overall frequency of hypertension more than five years was 55% subjects whereas 45% individuals had duration of hypertension less than five years. Mean RDW in females was found to be 49.35±8.42 fl while mean RDW in males was 44.78±7.11 fl. An independent sample t-test was applied to assess if there was any significant difference between age and gender. No significant difference between age and gender was found (p<0.05). The Mann-Whitney test was used to assess any association of RDW with gender. RDW values in females was found to be statistically significantly higher than in males (U=603, p=0.01). Linear regression showed that mean RDW value increased with increasing age (P <0.001).

CONCLUSIONS

A significant number of patients with hypertension have increased levels of RDW. Therefore, it is recommended that serum RDW should be checked regularly in patients with hypertension.

Red blood cell distribution width independently predicts medium-term mortality and major adverse cardiac events after an acute coronary syndrome

BACKGROUND

The value of red blood cell distribution width (RDW), a simple and inexpensive measure of anisocytosis, has been associated with the outcome of many human chronic disorders. Therefore, this retrospective study was aimed to investigate whether RDW may be associated with medium-term mortality and major adverse cardiac events (MACE) after an acute coronary syndrome (ACS).

METHODS

A total number of 979 patients diagnosed with ACS were enrolled from June 2014 to November 2014, and followed-up until June 2015.

RESULTS

The RDW value in patients with 3-month MACE and in those who died was significantly higher than that of patients without 3-month MACE (13.3% vs. 14.0%; P<0.001) and those who were still alive at the end of follow-up (13.4% vs. 14.4%; P<0.001). In univariate analysis, RDW was found to be associated with 3-month MACE [odds ratio (OR), 1.70; 95% CI, 1.44-2.00, P<0.001]. In multivariate analysis, RDW remained independently associated with 3-month MACE (adjusted OR, 1.36; 95% CI, 1.19-1.55; P<0.001) and death (adjusted OR, 1.34; 95% CI, 1.05-1.71; P=0.020). The accuracy of RDW for predicting 3-month MACE was 0.67 (95% CI, 0.66-0.72; P<0.001). The most efficient discriminatory RDW value was 14.8%, which was associated with 3.8 (95% CI, 2.6-5.7; P<0.001) higher risk of 3-month MACE. Patients with RDW >14.8% exhibited a significantly short survival than those with RDW ≤14.8% (331 vs. 465 days; P<0.001).

CONCLUSIONS

The results of this study confirm that RDW may be a valuable, easy and inexpensive parameter for stratifying the medium-term risk in patients with ACS.

Red Blood Cell Distribution Width to Platelet Ratio is Related to Histologic Severity of Primary Biliary Cirrhosis

We aimed to investigate whether red blood cell distribution width (RDW) and RDW to platelet ratio (RPR) were related to the histologic severity of primary biliary cirrhosis (PBC). Seventy-three treatment-naïve PBC patients who had undergone a liver biopsy between January 2010 and January 2015 were enrolled in our study. The patients' histological stages were based on the classifications of Ludwig and Scheuer. The patients were divided into early stage (Stage I) and advanced stage (Stage II, III, and IV) hepatic fibrosis according to their histological stage. All common patient demographics, clinical characteristics, hematological parameters, liver biochemistry, and antimitochondrial M2 antibody levels (AMA-M2) were retrospectively analyzed, and RDW, RPR, aspartate aminotransferase-to-platelet ratio index (APRI), and fibrosis index based on the 4 factors (FIB-4) were calculated. A total of 28 (38.4%) patients had early stage PBC, whereas 45 (62.6%) were classified as advanced stage. Regarding age, no significant differences between the early and advanced stages were observed. Patients with advanced stage PBC had significantly higher RDW (13.6 vs 14.4; P = 0.019), conjugated bilirubin (10.1 vs 23.4; P = 0.029), and significantly lower cholinesterase (7901.1 vs 6060.8; P = 0.001) and platelets (212.6 vs 167.0; P = 0.006). However, no significant differences (P > 0.05) in other routine parameters previously evaluated in PBC, including aspartate aminotransferase (AST) and mean platelet volume, were found between the groups. The sensitivity and specificity of RDW were 33.3% and 92.9%, respectively, and the area under the receiver-operating characteristic curve (AUROC) was 0.66. However, the sensitivity and specificity of RPR were 46.7% and 96.4%, respectively, and the corresponding AUROC was 0.74 (P < 0.001). Hence, compared with preexisting indicators, RPR showed a higher AUROC than APRI (0.648; P = 0.035) and FIB-4 (0.682; P = 0.009). RDW and RPR may be a new noninvasive marker for predicting histologic severity of PBC.

Red cell distribution width in anemic patients undergoing transcatheter aortic valve implantation

AIM: To determine the impact of red blood cell distribution width on outcome in anemic patients undergoing transcatheter aortic valve implantation (TAVI).

METHODS: In a retrospective single center cohort study we determined the impact of baseline red cell distribution width (RDW) and anemia on outcome in 376 patients with aortic stenosis undergoing TAVI. All patients were discussed in the institutional heart team and declined for surgical aortic valve replacement due to high operative risk. Collected data included patient characteristics, imaging findings, periprocedural in hospital data, laboratory results and follow up data. Blood samples for hematology and biochemistry analysis were taken from every patient before and at fixed intervals up to 72 h after TAVI including blood count and creatinine. Descriptive statistics were used for patient’s characteristics. Kaplan-Meier survival curves were used for time to event outcomes. A recursive partitioning regression and classification was used to investigate the association between potential risk factors and outcome variables.

RESULTS: Mean age in our study population was 81 ± 6.1 years. Anemia was prevalent in 63.6% (n = 239) of our patients. Age and creatinine were identified as risk factors for anemia. In our study population, anemia per se did influence 30-d mortality but did not predict longterm mortality. In contrast, a RDW > 14% showed to be highly predictable for a reduced short- and longterm survival in patients with aortic valve disease after TAVI procedure.

CONCLUSION: Age and kidney function determine the degree of anemia. The anisocytosis of red blood cells in anemic patients supplements prognostic information in addition to that derived from the WHO-based definition of anemia.

Sex and Race-Ethnicity Secular Trends in Mean and Elevated Red Blood Cell Distribution Width Among Adults in the United States, 1999-2012

OBJECTIVE

Red blood cell distribution width (RDW) has been shown to associate with increased risk of cardiovascular and non-cardiovascular death. To our knowledge, no study has examined secular trends in RDW over the last decade.

DESIGN

Serial cross-sectional design.

SETTING

Data from the National Health and Nutrition Examination Survey (NHANES), 1999-2012, were used.

PATIENTS

34,171 adults.

MAIN OUTCOME MEASURES

RDW was assessed from a blood sample derived from the coefficient of variation of the red cell volume distribution histogram and reported as a percent. Elevated RDW was defined as an RDW > 14.6%.

RESULTS

The overall age-adjusted mean RDW increased progressively and significantly (P<.05) from 12.59% in 1999-2000 to 12.89% in 2011-2012. The overall age-adjusted prevalence of elevated RDW increased progressively and significantly (P<.05) from 4.01% in 1999-2000 to 6.25% in 2011-2012. Statistically significant increases over this time period also occurred among non-Hispanic White women, non-Hispanic Black men and women, and Mexican American men and women. Across all sex and race-ethnicity combinations, women, compared with men, had higher RDW and larger increases over time in mean and elevated RDW.

CONCLUSIONS

Mean and elevated RDW has progressively increased from 1999-2012 among adults in the United States, with increases observed among non-Hispanic Whites, Blacks, and Mexican Americans. Future research is needed to describe the determinants and implications of this RDW rise, as well as explanations for why a greater RDW change has occurred among women.

Red blood cell distribution width levels correlate with liver fibrosis and inflammation: a noninvasive serum marker panel to predict the severity of fibrosis and inflammation in patients with hepatitis B

We aimed to study whether red blood cell distribution width (RDW) could be one of the variables determining the extent of liver fibrosis and inflammation in patients with biopsy-proven hepatitis B. A total of 446 hepatitis B virus-infected patients who underwent liver biopsy were divided into 2 groups: absent or mild and moderate-severe according to the severity of liver fibrosis and inflammation. The independent variables that determine the severity of liver fibrosis and inflammation were explored. RDW values increased with progressive liver fibrosis and inflammation. After adjustments for other potent predictors, liver fibrosis (moderate-severe) was independently associated with RDW, platelet, and albumin (odds ratio = 1.121, 0.987, and 0.941, respectively), whereas increased odds ratios of significant inflammation were found for RDW, alanine aminotransferase, albumin, and PLT (odds ratio = 1.146, 1.003, 0.927, and 0.990, respectively). The sensitivity and specificity of model A were 70.0% and 62.9% for detection of significant liver fibrosis [area under the receiver-operating characteristic curve (AUC) = 0.713, P < 0.001]. The sensitivity and specificity of model B were 66.1% and 79.4% for predicting advanced liver inflammation (AUC = 0.765, P < 0.001). Compared with preexisting indicators, model A achieved the highest AUC, whereas model B showed a higher AUC than RDW to platelet ratio (0.670, P < 0.001) and FIB-4 (0.740, P = 0.32). RDW may provide a useful clinical value for predicting liver fibrosis and necroinflammation in hepatitis B-infected patients with other markers.