The Predictive Role of Red Cell Distribution Width in Mortality among Chronic Kidney Disease Patients

One Heartbeat Away from a Prediction Model for Cardiovascular Diseases in Patients with Chronic Kidney Disease: A Systematic Review

INTRODUCTION

Patients with chronic kidney disease (CKD) have a high risk of cardiovascular disease (CVD). Prediction models, combining clinical and laboratory characteristics, are commonly used to estimate an individual's CVD risk. However, these models are not specifically developed for patients with CKD and may therefore be less accurate. In this review, we aim to give an overview of CVD prognostic studies available, and their methodological quality, specifically for patients with CKD.

METHODS

MEDLINE was searched for papers reporting CVD prognostic studies in patients with CKD published between 2012 and 2021. Characteristics regarding patients, study design, outcome measurement, and prediction models were compared between included studies. The risk of bias of studies reporting on prognostic factors or the development/validation of a prediction model was assessed with, respectively, the QUIPS and PROBAST tool.

RESULTS

In total, 134 studies were included, of which 123 studies tested the incremental value of one or more predictors to existing models or common risk factors, while only 11 studies reported on the development or validation of a prediction model. Substantial heterogeneity in cohort and study characteristics, such as sample size, event rate, and definition of outcome measurements, was observed across studies. The most common predictors were age (87%), sex (75%), diabetes (70%), and estimated glomerular filtration rate (69%). Most of the studies on prognostic factors have methodological shortcomings, mostly due to a lack of reporting on clinical and methodological information. Of the 11 studies on prediction models, six developed and internally validated a model and four externally validated existing or developed models. Only one study on prognostic models showed a low risk of bias and high applicability.

CONCLUSION

A large quantity of prognostic studies has been published, yet their usefulness remains unclear due to incomplete presentation, and lack of external validation of prognostic models. Our review can be used to select the most appropriate prognostic model depending on the patient population, outcome, and risk of bias. Future collaborative efforts should aim at improving existing models by externally validating them, evaluating the addition of new predictors, and assessment of the clinical impact.

REGISTRATION

We have registered the protocol of our systematic review on PROSPERO (CRD42021228043).

Association of Red Blood Cell Distribution Width and Neutrophil-to-Lymphocyte Ratio with Calcification and Cardiovascular Markers in Chronic Kidney Disease

We aimed to investigate the association between Red Blood Cell Distribution Width (RDW) and Neutrophil-to-Lymphocyte Ratio (NLR), simple, rapidly assessed markers from the complete blood count with vascular calcification (VC)/stiffness and cardiovascular disease (CVD) in chronic kidney disease (CKD). Dephosphorylated, uncarboxylated matrix Gla-protein (dp-ucMGP), and central/peripheral hemodynamics' parameters were measured in 158 CKD patients, including Hemodialysis and Peritoneal Dialysis. Spearman's rho analysis showed that RDW correlated with C-reactive protein (CRP) (r = 0.29, p < 0.001), dp-ucMGP (r = 0.43, p = < 0.0001), central diastolic blood pressure (DBP) (r = -0.19, p = 0.02), and albuminuria (r = -0.17, p = 0.03). NLR correlated with the duration of CVD (r = 0.32, p < 0.001), CRP (r = 0.27, p = 0.01), dp-ucMGP (r = 0.43, p < 0.0001), central DBP (r = -0.32, p < 0.0001) and eGFR (r = -0.25, p = 0.04). In multiple regression models, circulating dp-ucMGP was an independent predictor of RDW (β = 0.001, p = 0.001) and NLR (β = 0.002, p = 0.002). In CKD patients, RDW and NLR are associated with traditional and novel markers of VC and CVD.

Red blood cell distribution width as a predictor of cardiovascular outcomes in extensive aortoiliac disease

BACKGROUND

Aortoiliac peripheral artery disease may lead to disabling lower limb claudication or to lower limb chronic threatening ischemia, which is associated with increased short and long-term morbi-mortality. The red blood cell distribution width-coefficient of variation (RDW-CV) has been able to predict outcomes in other atherosclerotic diseases, such as myocardial infarction and stroke. The main objective of this study was to assess the predictive ability of perioperative RDW-CV in accurately predicting short and long-term major adverse cardiovascular events (MACE) and all-cause mortality in patients submitted to aortoiliac revascularization due to extensive aortoiliac atherosclerotic disease.

METHODS

From 2013 to 2020, patients who underwent aortoiliac revascularization due to severe aortoiliac disease were included in a prospective cohort. Blood samples were taken preoperatively and the patient's demographics, comorbidities, and postoperative outcomes were assessed. A multivariate Cox regression model was used to adjust for confounding and assess the independent effect of these prognostic factors on the outcomes.

RESULTS

The study group included 107 patients. Median follow-up was 57 (95% CI: 34.4-69.6) months. Preoperative RDW-CV was increased in thirty-eight patients (35.5%). Increased RDW-CV was associated with congestive heart failure - adjusted odds ratio of 5.043 (95% CI: 1.436-17.717, P=0.012). It could predict long-term occurrence of MACE (adjusted hazard ratio [aHR] 1.065, 95% CI: 1.014-1.118, P=0.011), all-cause mortality (aHR=1.069, 95% CI: 1.014-1.126, P=0.013), acute heart failure (AHF) (aHR=1.569, 95% CI: 1.179-2.088, P=0.002), and stroke (aHR=1.343, 95% CI: 1.044-1.727, P=0.022).

CONCLUSIONS

RDW is a widely available and low-cost marker that was able to independently predict long-term AHF, stroke, MACE, and all-cause mortality in patients with extensive aortoiliac disease submitted to revascularization. This biomarker could help assess which patients would likely benefit from stricter follow-up in the long-term.

The effects of mean platelet volume and red cell distribution width on prognosis in patients with myelodysplastic syndrome

Objective: In this study, the relationship between changes in mean platelet volume (MPV) and erythrocyte distribution width (RDW) with hematological response and survival in patients with myelodysplastic syndrome was investigated. Patients and Methods: Between 1 January 2011 and 31 December 2018, patient characteristics and hemogram results were evaluated during the treatment process among 158 patients diagnosed with myelodysplastic syndrome. Results: The mean age of the patients who were included in the study was 71.53±12.6 years. The MPV percentage change in the 2-year follow-up of the patients with and without hematological response was significant, at 0.022±0.11 (2.2%) in those who responded and at 0.069±0.15 (6.9%) in those who did not (p=0.049). Throughout the same period, the degree of RDW changes in the patients who died was 13.23±22.97, the degree in those who survived was 2.86±21.42, and the difference between the two groups was statistically significant (p=0.006). Conclusion: In patients diagnosed with myelodysplastic syndrome, MPV and RDW values can be considered inexpensive and simple laboratory markers that can be used in follow-ups and promising tests to predict both treatment response and survival in the early period and change treatment modalities.

The Effects of Nordic Walking with Poles with an Integrated Resistance Shock Absorber on Red Blood Cell Distribution and Cardiorespiratory Efficiency in Postmenopausal Women-A Randomized Controlled Trial

BACKGROUND

Age-related reduction in exercise capacity is manifested by a rapid development of fatigue. Research confirmed the adverse prognostic value of red blood cell distribution width (RDW-CV), an independent factor in heart failure, coronary heart disease and myocardial infarction. Physical exercise improves and helps to maintain cardiorespiratory fitness. The aim of our study was to examine the impact of 8 weeks' Nordic walking training with classic poles (NW) and NW training with poles with an integrated resistance shock absorber (NW with RSA) on RDW-CV levels and to assess correlations between RDW-CV levels and cardiorespiratory performance in postmenopausal women.

METHODS

In this study, 32 postmenopausal women (NW-16, NW with RSA-16) participated in eight weeks of walking training. The mean age of women was 66.56 ± 4.23 year. and BMI 26.99 ± 3.86 kg/m². At the beginning and at the end of the study, spirometry and exercise tests were performed. Haematological parameters were determined in the venous blood.

RESULTS

Statistical analysis of differences in post-training changes in the parameters between the groups studied showed a significant difference in change in body weight (∆body weight) (p < 0.05; ES: 0.778), BMI (∆BMI) (p < 0.05; ES: 0.778), waist circumference (∆WC) (p < 0.05; ES: 1.225) and (∆RDW-SD) (p < 0.05; ES: 1.215). There were no changes in electrocardiographic and spirometric parameters.

CONCLUSIONS

Based on the findings from the present study, it can be assumed that endurance and resistance exercise can significantly reduce disease severity and mortality. A clinical analysis of RDW levels, together with other cardiological and biochemical parameters, can provide practical prognostic information relating to cardiovascular disease, mortality risk and treatment outcomes.

Prognostic value of red cell distribution width and mean corpuscular volume on mortality in hemodialysis patients

BACKGROUND

Anemia is a common consequence of chronic kidney disease (CKD). Red cell distribution width (RDW) and mean corpuscular volume (MCV) are principally used for differential diagnosis of anemia. Limited evidence is available for its prognostic value for mortality in hemodialysis (HD) patients. We aimed to definite the relationship between RDW and MCV and mortality in HD patients.

METHOD

This cohort study examined all-cause and cardiovascular (CV) mortality with 181 maintenance HD patients from February 2015. Patients were divided into four groups according to the median of RDW and MCV. Pearson analysis was conducted to determine the related factors of RDW and MCV. The independent association of RDW and MCV with mortality was examined with Kaplan-Meier curve and Cox regression analysis.

RESULTS

This study included 181 HD patients for a median follow-up of 71 months. We found RDW was positively related to neutrophil count, C-reaction protein, and ferritin, while negatively related to hemoglobin, albumin, and creatinine. Only neutrophil count and ferritin were significantly related to MCV in this study. In the multivariate Cox regression analysis, the high RDW group was associated with higher risk of all-cause mortality (odds ratio, 3.787; 95% confidence interval, 1.037 to 13.834; p = 0.044). The relationship between RDW and MCV and CV mortality was not significant.

CONCLUSIONS

RDW could emerge as an additive risk factor for all-cause mortality in maintenance HD patients, independent of other factors. An absolute value of MCV to predict mortality and the underlying pathophysiologic mechanisms should be confirmed in the future.

Red cell distribution width is associated with short-term mortality in critically ill patients with heart failure

AIMS

There is limited evidence for the correlation between short-term mortality and red cell distribution width (RDW) in critical patients with heart failure. Herein, a retrospective cohort study was conducted to investigate whether RDW was independently associated with short-term mortality in critically ill patients with heart failure.

METHODS AND RESULTS

As a retrospective cohort study, it involved a total of 9465 patients with heart failure from the MIMIC-IV database. The target-dependent and independent variables were in-hospital mortality, 90 day mortality and RDW measured at baseline, respectively. The relationship between all-cause death and baseline RDW in hospital and after 90 days of admission to ICU was evaluated by using the Kaplan-Meier plot and Cox proportional hazard analysis. The average age of participants was 74.4 (64.2, 83.5) years old, among whom about 54.6% were male. Results of the adjusted Cox proportional hazard model revealed that RDW had a positive association with both in-hospital and 90 day mortality risk after the adjustment of confounders (HR = 1.09, 95% CI: 1.04-1.15, P < 0.001; HR = 1.11, 95% CI: 1.08-1.14, P < 0.001, respectively). A non-linear relationship was found between RDW and 90 day mortality, which had a threshold of 14.96%. The effect sizes and confidence intervals below and above the threshold were 1.36 (1.14 to 1.62) and 1.09 (1.04 to 1.15), respectively. It was also found by subgroup analysis that there were stronger correlations in male and patients with normal renal function.

CONCLUSIONS

Our data suggest that the short-term mortality of critically ill patients with HF is independently predicted by RDW. At the same time, large prospective research and longer follow-up time are required to further validate the findings of this study.

Influence of Red Blood Cell Distribution Width on All-Cause Death in Critical Diabetic Patients with Acute Kidney Injury

OBJECTIVE

To explore the relationship between red blood cell distribution width (RDW) and all-cause death in critical diabetic patients with acute kidney injury (AKI).

METHODS

The clinical data of critical diabetic patients with AKI in MIMIC-III database were analyzed retrospectively. According to the survival status of 28-day after AKI and levels of RDW, patients were divided into survival and death groups, high RDW (RDW > 15.3%) and low RDW groups (RDW ≤ 15.3%). Kaplan-Meier curves were used to compare the survival rates of diabetic patients with AKI in different RDW and AKI stages, and Cox regression analysis was used to evaluate the risk factors of 28-day all-cause death in critical diabetic patients with AKI.

RESULTS

A total of 5200 patients with critical diabetic patients with AKI were included in this study with the male to female ratio of 1.53:1. The mean follow-up time was 24.97 ± 7.14 days, and the 28-day all-cause mortality was 17.9% (931/5200). Age, RDW, blood urea nitrogen, serum creatinine, lactic acid, proportion of AKI stage, sepsis and respiratory failure in the death group were higher than those in the survival group, while mean arterial pressure (MAP) and red blood cell count were lower than those in the survival group. Kaplan-Meier analysis showed that the 28-day survival rate of the high RDW group was significantly lower than that of the low RDW group (log-rank χ ² = 9.970, P = 0.002). Multivariate Cox regression analysis showed that advanced age (HR = 1.042, 95% CI = 1.021-1.063), decreased MAP (HR = 0.984, 95% CI = 0.969-0.998), stage 3 AKI (HR = 3.318, 95% CI = 1.598-6.890) and increased RDW (HR = 1.255, 95% CI = 1.123-1.403) were independent risk factors of 28-day all-cause death in critical diabetic patients with AKI (P < 0.05).

CONCLUSION

High level of RDW is an important risk factor of all-cause death in critical diabetic patients with AKI, and it may be used as a valuable index to classify the mortality.

Red Blood Cell Distribution Width Is Associated with Deterioration of Renal Function and Cardiovascular Morbidity and Mortality in Patients with Diabetic Kidney Disease

We sought to investigate the possible association between Red Blood Cell Distribution Width (RDW), vascular calcification, oxidative stress and renal function and all-cause/cardiovascular (CV) mortality, CV events and progression of kidney disease in a cohort of patients with Diabetic Kidney Disease (DKD). Carotid intima media thickness (cIMT) and oxidized low-density cholesterol were measured in 104 Type 2 Diabetes Mellitus (T2DM) patients with established DKD, distributed in all five stages of kidney disease and 38 diabetics with normal renal function. All patients were followed for 7 years with end-points all-cause and CV mortality, CV events and progression to End-Stage Renal Disease (ESRD). RDW was positively correlated with diabetes duration (r = 0.19, p = 0.023) and albuminuria (r = 0.29, p = 0.002). Multivariate regression analysis revealed that RDW was a strong, independent predictor of cIMT value (β = 0.031, p = 0.012). Kaplan-Meier curves and Cox proportional hazard models revealed that after adjustment for several cofounders, RDW was a significant and independent predictor for all-cause mortality, CV mortality, CV event and progression to ESRD (HR 1.75, p = 0.001, HR 2.03, p = 0.001, HR = 1.66, p < 0.0001 and HR 2.14, p = 0.001 respectively). RDW predicts mortality, CV events and deterioration of renal function in DKD, probably reflecting atherosclerosis.

High red blood cell distribution width is associated with a risk of short-term mortality in hospitalized surgical, but not clinical patients

BACKGROUND & AIMS

The distribution width of red blood cells (RDW) is a known factor risk for mortality. However, the association between high RDW and short-term mortality in surgical patients is poorly understood. The aim of this study was to evaluate the association of high RDW with all-cause in-hospital mortality, in surgical and non-surgical patients.

METHODS

A retrospective study was performed with patients aged 18 years or older, hospitalized in Clinical Medical and Surgery wards, using adjustments based on a conceptual model. Cox regression was used to determine the independent predictors of in-hospital mortality. The RDW cutoff value was 13.6%.

RESULTS

Of the 2923 patients, 46.1% were over 60 years old, 58.7% were male and 4.7% died. The area under the ROC curve was 0.677 (CI 95%: 0.619-0.712). RDW was associated with an adjusted risk for all-cause in-hospital mortality in surgical (HR 1.17 - CI 95%: 1.03-1.32), but not in clinical patients. For every 1% increase in RDW, the risk of all-cause hospital death in surgical patients increased by 17%. RDW ≥13.6% was associated with an adjusted risk of all cause in-hospital mortality in surgical (HR 2.65 - 95%CI: 1.22-5.73), but not in clinical patients.

CONCLUSIONS

High RDW was associated with a risk of in-hospital mortality independent of age, sex, hemoglobin level, multimorbidity, nutritional status and immunological condition. We therefore recommend the use of RDW as a possible marker of mortality risk in clinical practice in surgical patients.

[Comparative analysis of RDW variability depending on belonging to a defined nosological group of diseases according to ICD-10 classification.]

The aim of this study was to investigate RDW variability and conduct a comparative analysis of the RDW level in patients depending on their belonging to a defined nosological group of diseases according to the ICD-10 classification. All patients who complete blood count tests in our hospital from January to December 2016 were included in the study. The identification of the patient's belonging to a specific nosological group according to the ICD-10 classification was carried out on the basis of the disease analysis code indicated in the direction of the blood test. 8056 patient records were included in the final analysis. Deviations beyond the upper reference range for the RDW indicator (> 14.5%) in this study were identified for patients of the following nosological groups according to ICD-10: C - neoplasms; D - blood diseases; S - injuries; T - poisoning. Significant intergroup differences were obtained according to the Kruskal-Wallis rank analysis of variance (Kruskal-Wallis test: H (19, n= 7622) = 214.9672 p = 0.0000). According to the results of this study, we can conclude that RDW has specificity for certain diseases (neoplasms; blood diseases; injuries; poisoning). In case of cardiovascular and other diseases, deviations of this indicator beyond the limits of the upper reference values were not found in this study.

Ancestry-specific associations identified in genome-wide combined-phenotype study of red blood cell traits emphasize benefits of diversity in genomics

BACKGROUND

Quantitative red blood cell (RBC) traits are highly polygenic clinically relevant traits, with approximately 500 reported GWAS loci. The majority of RBC trait GWAS have been performed in European- or East Asian-ancestry populations, despite evidence that rare or ancestry-specific variation contributes substantially to RBC trait heritability. Recently developed combined-phenotype methods which leverage genetic trait correlation to improve statistical power have not yet been applied to these traits. Here we leveraged correlation of seven quantitative RBC traits in performing a combined-phenotype analysis in a multi-ethnic study population.

RESULTS

We used the adaptive sum of powered scores (aSPU) test to assess combined-phenotype associations between ~ 21 million SNPs and seven RBC traits in a multi-ethnic population (maximum n = 67,885 participants; 24% African American, 30% Hispanic/Latino, and 43% European American; 76% female). Thirty-nine loci in our multi-ethnic population contained at least one significant association signal (p < 5E-9), with lead SNPs at nine loci significantly associated with three or more RBC traits. A majority of the lead SNPs were common (MAF > 5%) across all ancestral populations. Nineteen additional independent association signals were identified at seven known loci (HFE, KIT, HBS1L/MYB, CITED2/FILNC1, ABO, HBA1/2, and PLIN4/5). For example, the HBA1/2 locus contained 14 conditionally independent association signals, 11 of which were previously unreported and are specific to African and Amerindian ancestries. One variant in this region was common in all ancestries, but exhibited a narrower LD block in African Americans than European Americans or Hispanics/Latinos. GTEx eQTL analysis of all independent lead SNPs yielded 31 significant associations in relevant tissues, over half of which were not at the gene immediately proximal to the lead SNP.

CONCLUSION

This work identified seven loci containing multiple independent association signals for RBC traits using a combined-phenotype approach, which may improve discovery in genetically correlated traits. Highly complex genetic architecture at the HBA1/2 locus was only revealed by the inclusion of African Americans and Hispanics/Latinos, underscoring the continued importance of expanding large GWAS to include ancestrally diverse populations.

Association between red blood cell distribution width and long-term mortality among patients undergoing percutaneous coronary intervention with previous history of cancer

Background: The number of patients suffering from coronary heart disease with cancer is rising. There is scarce evidence concerning the biomarkers related to prognosis among patients undergoing percutaneous coronary intervention (PCI) with cancer. Thus, the aim of this study was to investigate the association between red blood cell distribution width (RDW) and prognosis in this population.Methods: A total of 172 patients undergoing PCI with previous history of cancer were enrolled in this retrospective study. The endpoint was long-term all-cause mortality. According to tertiles of RDW, the patients were classified into three groups: Tertile 1 (RDW <12.8%), Tertile 2 (RDW ≥12.8% and <13.5%) and Tertile 3 (RDW ≥13.5%).Results: During an average follow-up period of 33.3 months, 29 deaths occurred. Compared with Tertile 3, mortality of Tertile 1 and Tertile 2 was significantly lower in the Kaplan-Meier analysis. In multivariate Cox regression analysis, RDW remained an independent risk factor of mortality (HR: 1.938, 95% CI: 1.295-2.655, p < 0.001). The all-cause mortality in Tertile 3 was significantly higher than that in Tertile 1 (HR: 5.766; 95% CI: 1.426-23.310, p = 0.014).Conclusions: An elevated RDW level (≥13.5%) was associated with long-term all-cause mortality among patients undergoing PCI with previous history of cancer.

The prognostic value of red blood cell characteristics on diabetic retinopathy development and progression in type 2 diabetes mellitus

BACKGROUNDAlthough it is considered that the pathogenesis of diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM) is primarily due to chronic hyperglycemia resulting in vascular changes and retinal ischemia, the red blood cells (RBCs) disorders might also represent an important pathophysiological risk factor.OBJECTIVETo evaluate whether the RBC properties contribute to DR development and progression in T2DM.METHODSThis prospective observational study comprised 247 persons with T2DM free of DR or with non proliferative DR without any signs of anaemia. The patients were reacessed after 60-months.RESULTSThe mean age of our study population was 56 years, 54.9% males with diabetes duration of 11,18±1,28 years. During the follow up, 16 (5.84%) participants developed non proliferative DR and 9 (3.64%) progressed to PDR while the mean corpuscular volume (MCV) and red cell distribution width (RDW) MCV rose. Both MCV and RDW correlated positively with HbA1c (r = 0,468, p = 0.003 and r = 0.521, p < 0.001), while Cox regression analysis revealed that besides age, diabetes duration, HbA1c, hypertension and dyslipidemia presence, MCV and RDW are also associated with the risk of DR development and progression (HR 1.057 and 1.237, p < 0.001).CONCLUSIONSWe clearly demonstrated that RBC's characteristics might represent a risk factor for DR development and progression.

A single preoperative blood test predicts postoperative sepsis and pneumonia after coronary bypass or open aneurysm surgery

BACKGROUND

Major surgery comes with a high risk for postoperative inflammatory complications. Preoperative risk scores predict mortality risk but fail to identify patients at risk for complications following cardiovascular surgery. We therefore assessed the value of preoperative red cell distribution width (RDW) as a predictor for pneumonia and sepsis after cardiovascular surgery and studied the relation of RDW with hematopoietic tissue activity.

METHODS

RDW is an easily accessible, yet seldomly used parameter from routine haematology measurements. RDW was extracted from the Utrecht Patient Orientated Database (UPOD) for preoperative measurements in patients undergoing open abdominal aortic anuerysm repair (AAA)(N = 136) or coronary artery bypass grafting (CABG)(N = 2193). The cohorts were stratified in tertiles to assess effects over the different groups. Generalized Linear Models were used to determine associations between RDW and postoperative inflammatory complications. Hematopoietic tissue activity was scored using fluor-18-(18F)-deoxyglucose positron emission tomography and associated with RDW using linear regression models.

RESULTS

In total, 43(31.6%) and 73 patients (3.3%) suffered from inflammatory complications after AAA-repair or CABG, respectively; the majority being pneumonia in both cohorts. Postoperative inflammatory outcome incidence increased from 19.6% in the lowest to 48.9% in the highest RDW tertile with a corresponding risk ratio (RR) of 2.35 ([95%CI:1.08-5.14] P = 0.032) in AAA patients. In the CABG cohort, the incidence of postoperative inflammatory outcomes increased from 1.8% to 5.3% with an adjusted RR of 1.95 ([95%CI:1.02-3.75] P = 0.044) for the highest RDW tertile compared with the lowest RDW tertile. FDG-PET scans showed associations of RDW with tissue activity in the spleen (B = 0.517 [P = 0.001]) and the lumbar bone marrow (B = 0.480 [P = 0.004]).

CONCLUSION

Elevated RDW associates with increased risk for postoperative inflammatory complications and hematopoietic tissue activity. RDW likely reflects chronic low-grade inflammation and should be considered to identify patients at risk for postoperative inflammatory complications following cardiovascular surgery.

Red cell distribution width and renal outcome in patients with non-dialysis-dependent chronic kidney disease

Higher red cell distribution width (RDW) has been reported to predict mortality among patients with various diseases, including chronic kidney disease (CKD). However, whether RDW is associated with renal outcome remains unclear. We investigated the relationship between RDW and renal outcome in patients with non-dialysis-dependent CKD (NDD-CKD). This prospective, observational study of patients with CKD was conducted at a single nephrology department. First, we performed regression analyses for the decline in estimated glomerular filtration rate (eGFR) during the first 3 months of observation to determine its short-term association with RDW. Next, we categorized baseline RDW into two groups by its median (13.5%) and performed Cox regression analyses to investigate whether higher RDW was an independent predictor of renal outcomes defined as a composite of the initiation of dialysis and doubling of the serum creatinine concentration. Furthermore, we repeated the analyses to confirm whether the transition of the RDW category during the first 3 months would also predict renal outcomes. We enrolled 703 patients. Baseline RDW showed a non-linear association with the eGFR decline during the first 3 months, with a greater negative correlation at the lower end of the RDW distribution. Over a median follow-up of 1.8 years, 178 patients (25.3%) reached the renal endpoint. Multivariable Cox regression analyses showed that patients with higher RDW had a higher risk of developing renal outcomes (adjusted hazard ratio [HR]: 1.47, 95% confidence interval [CI]: 1.05–2.07) than did those with lower RDW. Furthermore, patients with sustained, higher RDW demonstrated a significantly higher risk than did those with consistently lower RDW (adjusted HR: 1.65, 95% CI: 1.02–2.67). In conclusion, higher RDW was independently associated with worse renal outcome in patients with NDD-CKD. RDW could be an additional prognostic marker of the progression of CKD.

Hematological parameters and all-cause mortality: a prospective study of older people

Background

The effect of low and high concentration of some hematological parameters in the blood can have a negative impact on health.

Aim

Therefore, we investigated the associations between hematological parameters and all-cause mortality among older people living in Poland.

Methods

The study was carried out among 75–80-year-old participants (n = 403) from Warsaw and Olsztyn regions, Poland. Information on lifestyle factors and food consumption were obtained at baseline (June 1, 1999) using a self-administered questionnaire. Red blood cell, haemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) were determined. The data on deaths from all-causes were collected from the baseline until October 31, 2006. During an average of 7.4 years of follow-up, we ascertained 154 cases of death from all-causes.

Results

Compared with men in the lowest tertile of MCV, MCH, and MCHC, the multivariable hazard ratios (HRs) of all-cause mortality in those in the highest tertile were 0.35 (95% CI, 0.17–0.73), 0.32 (95% CI, 0.16–0.67), and 0.44 (95% CI, 0.22–0.88), respectively. In contrast, among women after combining the second and the third tertiles of MCV, MCH, and MCHC, the HRs were 2.01 (95% CI, 1.01–3.99), 1.71 (95% CI, 0.85–3.43), and 1.09 (95% CI, 0.62–1.94), respectively.

Discussion/conclusion

We observed inverse associations between some hematological parameters and all-cause mortality among men, but not among women. This may be explained by a difference in iron metabolism, iron status, hormone regulations, or the occurrence of some diseases.

Red cell distribution width associated with adverse cardiovascular outcomes in patients with chronic kidney disease

Background

Recent studies have demonstrated that red cell distribution width (RDW) is associated with cardiovascular (CV) events and mortality. Patients with chronic kidney disease (CKD) are often anemic and have high RDW levels. In this study, we investigated the effect of RDW on major composite CV outcomes among patients with CKD.

Methods

We retrospectively analyzed patients with CKD who were admitted to the department of cardiology of a tertiary hospital in 2011. The patients were divided into 2 groups: normal RDW (RDW < 14.5%) and elevated RDW (RDW ≥ 14.5%). Demographic characteristics, comorbidities, blood investigation results, prescriptions, and outcomes were analyzed after a 3-year follow-up period. Six adjustment levels were performed to evaluate the effect of RDW on outcomes.

Results

This study involved 282 patients with CKD: 213 in the elevated RDW group and 69 in the normal RDW group. The elevated RDW group had older patients, a lower proportion of male patients, lower left ventricular ejection fraction (LVEF) values, lower hemoglobin levels, lower serum albumin levels, and higher creatinine levels, compared with the normal RDW group. A linear trend was observed toward higher RDW in patients with deteriorating renal function. In the final adjusted model, RDW ≥ 14.5%, older age, and lower LVEF were associated with an increased risk of major composite CV outcomes.

Conclusion

RDW is a potentially useful cost-effective indicator of major composite CV outcomes in patients with CKD.

Red Blood Cell Distribution Width is an Independent Predictor of AKI and Mortality in Patients in the Coronary Care Unit

BACKGROUND/AIMS

We investigated the hypothesis that RDW is an independent predictor of acute kidney injury (AKI) and mortality in patients in the coronary care unit (CCU).

METHODS

In this prospective, observational study, we screened 412 adults admitted to the CCU at Zhongnan Hospital of Wuhan University from January 1, 2014 to June 1, 2015. AKI was defined based on the KDIGO-AKI criteria. The survivors were followed up for up to 2 years after hospital discharge. The primary endpoint of the study was the incidence of AKI, while the secondary endpoints of the study were in-hospital mortality and 2-year mortality.

RESULTS

RDW was significantly correlated with the acute physiology and chronic health evaluation II (APACHEII) score, hemoglobin, mean corpuscular volume, inflammatory marker levels, nutrition and renal function at the time of CCU admission. The incidence of AKI was much higher in the high RDW group (RDW ≥14.0%) than in the low RDW group, a finding that was confirmed by multivariable logistic regression, which showed that RDW was independently associated with the incidence of AKI (odds ratio (OR), 1.059, 95% coincidence interval (95% CI), 1.024-1.095, P=0.001). A total of 61 patients died during their hospital stay, and baseline RDW was also an independent predictor of in-hospital mortality (hazard ratio (HR), 1.129, 95% CI 1.005-1.268, P=0.041). Patients with a high RDW exhibited significantly higher 2-year mortality than patients with a low RDW during a median follow-up period of 19.8 months (P<0.001), and RDW independently predicted the risk of 2-year mortality (HR, 1.189, 95% CI 1.045 to 1.354, P=0.009) in the multivariate Cox proportional hazard analysis after adjustments for other clinical and laboratory variables.

CONCLUSION

RDW is an independent predictor of AKI and mortality in patients in the CCU.

Association Between Red Blood Cell Distribution Width and All-cause Mortality in Chronic Kidney Disease Patients: A Systematic Review and Meta-analysis

BACKGROUND

Considering results among previous studies regarding the relationship of red blood cell distribution width (RDW) and all-cause mortality in chronic kidney disease (CKD) patients, we aimed to perform a comprehensive meta-analysis to evaluate the potential association between RDW and all-cause mortality in CKD patients.

METHODS

We conducted a systematic literature using electronic databases (PubMed, Ovid, Embase and Web of Science) to identify the studies reporting the association between RDW and all-cause mortality in CKD patients. We searched the literatures published December 2016 or earlier. We used both fix-effects and random-effects models to calculate the overall effect estimate. A sensitivity analysis and subgroup analysis were performed to find the origin of heterogeneity.

RESULTS

We retrieved 9 studies with a total of 117,047 patients. For every 1% increase in RDW, the risk of all-cause mortality increased by 47% (HR 1.47, 95% CI 1.35-1.61) with no statistical heterogeneity among the studies (I² = 44.5%, p = 0.094). When RDW was entered as a categorical variable, mortality risk was significantly increased (HR 1.84, 95% CI 1.21-2.81). Heterogeneity among the studies was observed for all-cause mortality (I² = 82.3%, p = 0.001). We also performed a predefined subgroup analyses according to study population. We found that for every 1% increase in RDW, the risk of all-cause mortality in hemodialysis (HD) patients increased by 36% (HR 1.36, 95% CI 1.20-1.53).

CONCLUSIONS

Our meta-analysis suggests that high levels of RDW probably increase the risk of all-cause mortality in CKD patients.

Red cell distribution width predicts incident dipstick albuminuria in Korean adults without chronic kidney disease

BACKGROUND

Red cell distribution width (RDW) is an emerging marker of inflammation and a predictor of high cardiovascular morbidity and mortality as well as all-cause mortality. A previous cross-sectional study showed that RDW was associated with microalbuminuria, an indicator of target organ damage. However, the longitudinal association of RDW and development of albuminuria is not known.

METHODS

We analyzed 83,040 participants without chronic kidney disease (CKD) at baseline who underwent two health check-ups at a 4-year interval during 2005 to 2014. Urine albumin was determined by single urine dipstick semi-quantitative analysis, and incident albuminuria was defined as ≥ 1+ dipstick albumin at the second check-up. We used logistic regression analysis to determine the relationship between RDW and incident albuminuria.

RESULTS

Participants were divided into quartiles according to baseline RDW. After 4 years, 982 cases of incident albuminuria were observed. The cumulative incidences of albuminuria were 0.94, 1.05, 1.18, and 1.62% for the 1st through 4th quartiles of RDW, respectively. Multivariate logistic analysis showed that the odds ratios (95% confidence interval) for incident albuminuria compared to those in the 1st quartile were 1.11 (0.92-1.34), 1.26 (1.04-1.52), and 1.88 (1.58-2.24) for the 2nd, 3rd and 4th quartiles, respectively.

CONCLUSION

RDW was associated with development of albuminuria in relatively healthy Korean adults without CKD. Further research is needed to verify the role of RDW in the development of albuminuria and renal injury.