Red Cell Distribution Width and Mortality in Hemodialysis Patients

Red cell distribution width to albumin ratio predicts treatment failure in peritoneal dialysis-associated peritonitis

BACKGROUND

This study aims to investigate the potential correlation between baseline red cell distribution width (RDW) to albumin ratio (RAR) levels and treatment failure in peritoneal dialysis-associated peritonitis (PDAP) patients.

METHODS

A retrospective single-center study was conducted on 286 PDAP patients. Logistic regression and generalized estimation equation (GEE) analyses were employed to assess the relationship between RAR and treatment failure.

RESULTS

RAR emerged as a robust predictor of treatment failure in PDAP patients. Elevated RAR levels were associated with an increased risk of treatment failure, exhibiting a linear relationship. Even after adjusting for demographic and clinical variables, this association remained statistically significant. ROC analysis revealed that RAR outperformed RDW and albumin individually in predicting PDAP prognosis.

CONCLUSION

This study highlights RAR as a superior prognostic marker for treatment failure in PDAP patients, offering new insights into risk assessment and management strategies for this challenging condition.

Evaluating biomarkers for contrast-induced nephropathy following coronary interventions: an umbrella review on meta-analyses

BACKGROUND

Contrast-induced nephropathy (CIN) is a form of acute kidney injury (AKI) occurring in patients undergoing cardiac catheterization, such as coronary angiography (CAG) or percutaneous coronary intervention (PCI). Although the conventional criterion for CIN detection involves a rise in creatinine levels within 72 h after contrast media injection, several limitations exist in this definition. Up to now, various meta-analyses have been undertaken to assess the accuracy of different biomarkers of CIN prediction. However, the existing body of research lacks a cohesive overview. To address this gap, a comprehensive umbrella review was necessary to consolidate and summarize the outcomes of prior meta-analyses. This umbrella study aimed to offer a current, evidence-based understanding of the prognostic value of biomarkers in predicting CIN.

METHODS

A systematic search of international databases, including PubMed, Scopus, and Web of Science, from inception to December 12, 2023, was conducted to identify meta-analyses assessing biomarkers for CIN prediction. Our own meta-analysis was performed by extracting data from the included studies. Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were assessed using Meta-Disc and CMA softwares.

RESULTS

Twelve studies were ultimately included in the umbrella review. The results revealed that neutrophil gelatinase-associated lipocalin (NGAL) exhibited the highest area under the curve (AUC), followed by cystatin-C, urinary kidney injury molecule-1 (uKIM-1), and brain natriuretic peptide (BNP) with AUCs of 0.91, 0.89, 0.85, and 0.80, respectively. NGAL also demonstrated the highest positive likelihood ratio [effect size (ES): 6.02, 95% CI 3.86-9.40], followed by cystatin-C, uKIM-1, and BNP [ES: 4.35 (95% CI 2.85-6.65), 3.58 (95% CI 2.75-4.66), and 2.85 (95% CI 2.13-3.82), respectively]. uKIM-1 and cystatin-C had the lowest negative likelihood ratio, followed by NGAL and BNP [ES: 0.25 (95% CI 0.17-0.37), ES: 0.25 (95% CI 0.13-0.50), ES: 0.26 (95% CI 0.17-0.41), and ES: 0.39 (0.28-0.53) respectively]. NGAL emerged as the biomarker with the highest diagnostic odds ratio for CIN, followed by cystatin-C, uKIM-1, BNP, gamma-glutamyl transferase, hypoalbuminemia, contrast media volume to creatinine clearance ratio, preprocedural hyperglycemia, red cell distribution width (RDW), hyperuricemia, neutrophil-to-lymphocyte ratio, C-reactive protein (CRP), high-sensitivity CRP, and low hematocrit (P < 0.05).

CONCLUSION

NGAL demonstrated superior diagnostic performance, exhibiting the highest AUC, positive likelihood ratio, and diagnostic odds ratio among biomarkers for CIN, followed by cystatin-C, and uKIM-1. These findings underscore the potential clinical utility of NGAL, cystatin-C and uKIM-1 in predicting and assessing CIN.

Ratio of hemoglobin to red cell distribution width: an inflammatory predictor of survival in AIDS-related DLBCL

Background

Despite the introduction of combined antiretroviral therapy, AIDS-related diffuse large B-cell lymphoma (AR-DLBCL) remains a prominent cancer among individuals living with HIV with a suboptimal prognosis. Identifying independent prognostic markers could improve risk stratification.

Methods

In this multicenter retrospective cohort study spanning years 2011 to 2019, 153 eligible patients with AR-DLBCL were examined. Overall survival (OS) factors were analyzed using Kaplan-Meier curves, and univariate and multivariate Cox proportional hazards models. The discriminatory ability of the risk score was evaluated by examining the area under the receiver operating characteristic curve.

Results

The study included 153 patients with a median age of 47 years (interquartile range [IQR] 39-58), 83.7% of whom were men. The median follow-up was 12.0 months (95% confidence interval [CI], 8.5-15.5), with an OS rate of 35.9%. Among the potential inflammatory markers examined, only the ratio of hemoglobin (g/dL) to red cell distribution width (%) (Hb/RDW) emerged as an independent prognostic parameter for OS in the training (hazard ratios [HR] = 2.645, 95% CI = 1.267-5.522, P = 0.010) and validation cohorts (HR = 2.645, 95% CI = 1.267-5.522, P = 0.010). A lower Hb/RDW ratio was strongly correlated with adverse clinical factors, including advanced Ann Arbor stage, increased extranodal sites, reduced CD4 count, elevated lactate dehydrogenase levels, poorer Eastern Cooperative Oncology Group performance status (ECOG PS), and a higher International Prognostic Index (IPI) score. The addition of the Hb/RDW ratio to the IPI produced a highly discriminatory prognostic composite score, termed Hb/RDW-IPI.

Conclusion

We identified a cost-effective and readily available inflammatory biomarker, the Hb/RDW ratio, as an independent predictor of outcomes in patients with AR-DLBCL. Its integration into the IPI score partially improves prognostic accuracy.

Development and validation of a nomogram for predicting in-hospital mortality in patients with nonhip femoral fractures

BACKGROUND

The incidence of nonhip femoral fractures is gradually increasing, but few studies have explored the risk factors for in-hospital death in patients with nonhip femoral fractures in the ICU or developed mortality prediction models. Therefore, we chose to study this specific patient group, hoping to help clinicians improve the prognosis of patients.

METHODS

This is a retrospective study based on the data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Least absolute shrinkage and selection operator (LASSO) regression was used to screen risk factors. The receiver operating characteristic (ROC) curve was drawn, and the areas under the curve (AUC), net reclassification index (NRI) and integrated discrimination improvement (IDI) were calculated to evaluate the discrimination of the model. The consistency between the actual probability and the predicted probability was assessed by the calibration curve and Hosmer-Lemeshow goodness of fit test (HL test). Decision curve analysis (DCA) was performed, and the nomogram was compared with the scoring system commonly used in clinical practice to evaluate the clinical net benefit.

RESULTS

The LASSO regression analysis showed that heart rate, temperature, red blood cell distribution width, blood urea nitrogen, Glasgow Coma Scale (GCS), Simplified Acute Physiology Score II (SAPSII), Charlson comorbidity index and cerebrovascular disease were independent risk factors for in-hospital death in patients with nonhip femoral fractures. The AUC, IDI and NRI of our model in the training set and validation set were better than those of the GCS and SAPSII scoring systems. The calibration curve and HL test results showed that our model prediction results were in good agreement with the actual results (P = 0.833 for the HL test of the training set and P = 0.767 for the HL test of the validation set). DCA showed that our model had a better clinical net benefit than the GCS and SAPSII scoring systems.

CONCLUSION

In this study, the independent risk factors for in-hospital death in patients with nonhip femoral fractures were determined, and a prediction model was constructed. The results of this study may help to improve the clinical prognosis of patients with nonhip femoral fractures.

Association of red blood cell distribution width with hospital admission and in-hospital mortality across all-cause adult emergency department visits

Objectives

To test the association between the initial red blood cell distribution width (RDW) value in the emergency department (ED) and hospital admission and, among those admitted, in-hospital mortality.

Materials and Methods

We perform a retrospective analysis of 210 930 adult ED visits with complete blood count results from March 2013 to February 2022. Primary outcomes were hospital admission and in-hospital mortality. Variables for each visit included demographics, comorbidities, vital signs, basic metabolic panel, complete blood count, and final diagnosis. The association of each outcome with the initial RDW value was calculated across 3 age groups (<45, 45-65, and >65) as well as across 374 diagnosis categories. Logistic regression (LR) and XGBoost models using all variables excluding final diagnoses were built to test whether RDW was a highly weighted and informative predictor for each outcome. Finally, simplified models using only age, sex, and vital signs were built to test whether RDW had additive predictive value.

Results

Compared to that of discharged visits (mean [SD]: 13.8 [2.03]), RDW was significantly elevated in visits that resulted in admission (15.1 [2.72]) and, among admissions, those resulting in intensive care unit stay (15.3 [2.88]) and/or death (16.8 [3.25]). This relationship held across age groups as well as across various diagnosis categories. An RDW >16 achieved 90% specificity for hospital admission, while an RDW >18.5 achieved 90% specificity for in-hospital mortality. LR achieved a test area under the curve (AUC) of 0.77 (95% confidence interval [CI] 0.77-0.78) for hospital admission and 0.85 (95% CI 0.81-0.88) for in-hospital mortality, while XGBoost achieved a test AUC of 0.90 (95% CI 0.89-0.90) for hospital admission and 0.96 (95% CI 0.94-0.97) for in-hospital mortality. RDW had high scaled weights and information gain for both outcomes and had additive value in simplified models predicting hospital admission.

Discussion

Elevated RDW, previously associated with mortality in myocardial infarction, pulmonary embolism, heart failure, sepsis, and COVID-19, is associated with hospital admission and in-hospital mortality across all-cause adult ED visits. Used alone, elevated RDW may be a specific, but not sensitive, test for both outcomes, with multivariate LR and XGBoost models showing significantly improved test characteristics.

Conclusions

RDW, a component of the complete blood count panel routinely ordered as the initial workup for the undifferentiated patient, may be a generalizable biomarker for acuity in the ED.

Impact of red blood cell distribution width-albumin ratio on prognosis of patients with CKD

The red blood cell distribution width-albumin ratio (RAR) is a prognostic factor for adverse outcomes in various populations. However, whether RAR is associated with renal outcomes remains unclear. Therefore, we aimed to investigate the impact of RAR on the prognosis in patients with chronic kidney disease (CKD). We conducted a retrospective cohort study using 997 CKD patients who were enrolled in the Fukushima Cohort Study. Patients were categorized into tertiles (T1-3) according to the baseline RAR. The associations of RAR with end-stage kidney disease (ESKD) were assessed using Kaplan-Meier curves and multivariable cox regression analyses. Receiver operating characteristic (ROC) curves were performed to test whether significant differences were present between red cell distribution width (RDW) and RAR. The median age was 66, 57% were men, the median eGFR was 47.8 ml/min/1.73 m2, and the median value of RAR was 3.5. The higher RAR group showed an increased risk for ESKD in the Kaplan-Meier curve analysis. Compared to the lowest RAR group, higher RAR groups had a higher risk of ESKD (hazard ratio [HR] 1.37, 95% CI 0.68-2.78 and 2.92, 95% CI 1.44-5.94) for T2 and T3 groups, respectively. ROC curve analysis proved that the discriminating ability of RAR for ESKD was superior to RDW. A higher RAR value was associated with worse renal outcomes in patients with CKD. RAR could be a convenient and useful prognostic marker for renal prognosis.

Association of red blood cell distribution width-to-albumin ratio with mortality in patients undergoing transcatheter aortic valve replacement

BACKGROUND

Frailty is associated with poor prognosis in patients undergoing transcatheter aortic valve replacement (TAVR). The red blood cell distribution width (RDW)-to-albumin ratio (RAR) reflects key components of frailty. This study aimed to evaluate the relationship between RAR and all-cause mortality in patients undergoing TAVR.

METHODS

The data were extracted from the Medical Information Mart for Intensive Care IV database. The RAR was computed by dividing the RDW by the albumin. The primary outcome was all-cause mortality within 1-year following TAVR. The association between RAR and the primary outcome was evaluated using the Kaplan-Meier survival curves, restricted cubic spline (RCS), and Cox proportional hazard regression models.

RESULTS

A total of 760 patients (52.9% male) with a median age of 84.0 years were assessed. The Kaplan-Meier survival curves showed that patients with higher RAR had higher mortality (log-rank P < 0.001). After adjustment for potential confounders, we found that a 1 unit increase in RAR was associated with a 46% increase in 1-year mortality (HR = 1.46, 95% CI:1.22-1.75, P < 0.001). According to the RAR tertiles, high RAR (RAR > 4.0) compared with the low RAR group (RAR < 3.5) significantly increased the risk of 1-year mortality (HR = 2.21, 95% CI: 1.23-3.95, P = 0.008). The RCS regression model revealed a continuous linear relationship between RAR and all-cause mortality. No significant interaction was observed in the subgroup analysis.

CONCLUSION

The RAR is independently associated with all-cause mortality in patients treated with TAVR. The higher the RAR, the higher the mortality. This simple indicator may be helpful for risk stratification of TAVR patients.

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.

In end-stage kidney disease, inflammation, erythron abnormalities and declined kidney function tests are accompanied by increased affective symptoms, chronic-fatigue, and fibromyalgia.. [DOI: 10.1101/2023.01.12.23284460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background

Numerous neuropsychiatric symptoms, including affective symptoms, chronic fatigue syndrome, and fibromyalgia symptoms, are present in patients with end-stage renal disease (ESRD). This study examines the relationship between neuropsychiatric symptoms and red blood cell (RBC) parameters, kidney function tests, zinc, C-reactive protein, and calcium levels in patients with ESRD.

Methods

The above biomarkers and the Beck-Depression Inventory, the Hamilton Anxiety Rating Scale, and the Fibro-Fatigue Rating Scale were measured in 70 patients with end-stage renal disease (ESRD) and 46 healthy controls.

Results

Increased scores of depressive, anxious, cognitive, and physiosomatic symptoms (including chronic fatigue, fibromyalgia, and autonomous symptoms) characterise ESRD. One latent vector could be extracted from these diverse symptom domains, which are, therefore, manifestations of a common core referred to as the physio-affective phenome. The combined effects of aberrations in red blood cells (RBC) (number of RBC, hematocrit, and haemoglobin), kidney function tests (glomerular filtration rate, ureum, creatinine, albumin, and total serum protein), C-reactive protein, zinc, and copper explained 85.0% of the variance in the physio-affective phenome. In addition, the effects of kidney function decline on the phenome were partially mediated by RBC aberrations and elevated copper, whereas the effects of dialysis frequency were entirely mediated by decreased zinc and elevated CRP.

Conclusions

Affective (depression and anxiety), cognitive, and physiosomatic symptoms due to ESRD are interrelated manifestations of the physio-affective phenome, which is driven by (in descending order of importance) kidney dysfunctions, erythron deficits, inflammation, elevated copper, and decreased zinc.

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 blood cell distribution width and all-cause mortality in congestive heart failure patients: a retrospective cohort study based on the Mimic-III database

Background

The red blood cell distribution width (RDW) is a metric that measures the variation in the size of red blood cells and is presented as the red blood cell volume coefficient of variation. Increased RDW levels are closely linked to an elevated risk of death from congestive heart failure (CHF) and might be a new risk marker for cardiovascular disease. This research sought to evaluate the possible link between RDW levels and all-cause mortality in CHF patients after controlling for other covariates.

Methods

The publicly accessible Mimic-III database served as the source of data for our research. We employed ICU admission scoring systems to gather information on each patient's demographical data, laboratory test results, comorbid conditions, vital signs, and scores. Among CHF patients, the link between baseline RDW levels and short-, medium-, and long-term all-cause mortality was evaluated by Cox proportional hazard analysis, smooth curve fitting, and Kaplan-Meier survival curves.

Results

In total, 4,955 participants were selected for the study with an average age of 72.3 ± 13.5 years (old) and with males accounting for 53.1%. The findings recorded from the fully adjusted Cox proportional hazard model showed that higher RDW was associated with a greater risk of 30-day, 90-day, 365-day, and 4-year all-cause death; the HRs and 95% confidence intervals were 1.11 (1.05, 1.16), 1.09 (1.04, 1.13), 1.10 (1.06, 1.14), and 1.10 (1.06, 1.13), respectively. The results were stable and reliable using subgroup analysis. Smooth curve fitting and the K-M survival curve method further validated our results.

Conclusion

The RDW levels had a u-shaped connection with 30-day mortality. The RDW level was linked to an elevated risk of short-, medium-, and long-term all-cause death among CHF patients.

The Role of the N-Terminal of the Prohormone Brain Natriuretic Peptide in Predicting Postoperative Multiple Organ Dysfunction Syndrome

BACKGROUND

Multiple organ dysfunction syndrome (MODS) is the progressive and potentially reversible dysfunction of at least two organ systems in the course of an acute and life-threatening disorder of systemic homeostasis. MODS is a serious post-cardiac-surgery complication in valvular heart disease that is associated with a high risk of death. This study assessed the predictive ability of selected preoperative and perioperative parameters for the occurrence of MODS in the early postoperative period in a group of patients with severe valvular heart disease.

METHODS

Subsequent patients with significant symptomatic valvular heart disease who underwent cardiac surgery were recruited in the study. The main end-point was postoperative MODS, defined as a dysfunction of at least two organs-perioperative stroke, heart failure requiring mechanical circulatory support, respiratory failure requiring mechanical ventilation, and postoperative acute kidney injury requiring renal replacement therapy. A logistic regression was used to assess relationships between variables.

RESULTS

There were 602 patients recruited for this study. The main end-point occurred in 40 patients. Preoperative NT-proBNP (OR 1.026; 95% CI 1.012-1.041; p = 0.001) and hemoglobin (OR 0.653; 95% CI 0.503-0.847; p = 0.003) are independent predictors of the primary end-point in a multivariate regression analysis. The cut-off point for the NT-proBNP value for postoperative MODS was calculated at 1300 pg/mL.

CONCLUSIONS

A high preoperative level of NTpro-BNP may be associated with the onset of MODS in the early postoperative period. The results of the study may also suggest that earlier cardiac surgery for significant valvular heart disease may be associated with an improved prognosis in this group of patients.

Red blood cell distribution width at admission predicts outcome in critically ill patients with kidney failure: a retrospective cohort study based on the MIMIC-IV database

PURPOSE

We aimed to explore whether red blood cell distribution width (RDW) could serve as a biomarker to predict outcomes in critically ill patients with kidney failure in this study.

MATERIALS AND METHODS

This retrospective study was conducted with the Medical Information Mart for Intensive Care IV (MIMIC-IV).A total of 674 patients were divided into three groups based on tertiles of RDW. We used the generalized additive model, Kaplan-Meier curve, and Cox proportional hazards models to evaluate the association between RDW and clinical outcomes. We then performed subgroup analyses to investigate the stability of the associations between RDW and all-cause mortality.

RESULTS

Nonlinear and J-shaped curves were observed in the generalized additive model. Kaplan-Meier analysis showed that patients with elevated RDW had a lower survival rate. The Cox regression model indicated that high levels of RDW were most closely associated with ICU mortality and 30-day mortality (HR = 4.71, 95% CI: 1.69-11.64 and HR = 6.62, 95% CI: 2.84-15.41). Subgroup analyses indicated that the associations between RDW and all-cause mortality were stable.

CONCLUSIONS

Elevated levels of RDW were associated with an increased risk of all-cause mortality, and RDW could be an independent prognostic factor for kidney failure.

Red cell distribution width and Glasgow coma scale score as predictors of in-hospital mortality in maintenance hemodialysis patients diagnosed with spontaneous intracerebral hemorrhage

Glasgow Coma Scale (GCS) score is being widely used as a useful predictor to investigate patients with head injury. High red cell distribution width (RDW) values have been independently associated with mortality and poor neurological outcome. However, there are few data available for Spontaneous Intracerebral Hemorrhage (SIH) in maintenance hemodialysis (MHD) patients. This study aimed to evaluate the prognostic value of the combined measurement of RDW and GCS score in MHD patients with SIH. We retrospectively studied 46 MHD patients who was admitted to our hospital for nontraumatic SIH from October 2014 to May 2020. Data including demographic information, cause of renal failure, comorbidities at ESRD, clinical and laboratory parameters at admission were collected from medical records. Univariate and multivariate Logistic regression analysis were performed to identify independent risk factors of the in-hospital Mortality in Hemodialysis Patients with SIH. The receiver operating characteristic curve (ROC) and areas under the curve (AUCs) were determined. The sensitivity and specificity of independent risk factors were calculated for a range of different cutoff points. A total of 46 patients were enrolled in the study. The in-hospital mortality rate was 69.57%. We divided subjects into 2 groups based on the clinical outcomes. Compared with survivors (n = 14), non-survivors (n = 32) had longer hemodialysis vintage (P = .017), lower GCS score (P < .001), higher hemoglobin (Hb) (P = .032) and RDW (P = .009). In multivariate logistic regression analysis, GCS score (OR 0.719, 95% CI 0.546-0.946; P = .018) and RDW (OR 4.549, 95% CI 1.243-0.946; P = .018) were independent risk factors of in-hospital mortality in MHD patients with SIH. The area under the ROC curve (AUC) for GCS score was 0.849 (95% CI 0.729-0.970) while that for RDW was 0.743 (95% CI 0.596-0.891). The AUC for the combined prediction was 0.916 (95% CI 0.828-1.000), with a sensitivity of 90.63% and a specificity of 88.46%. In conclusion, high RDW and low GCS score were useful and independent poor prognostic markers for in-hospital mortality of MHD patients with SIH.

Distribution Width of Red Blood Cells and Related Factors Among Patients with End-Stage Renal Disease in Addis Ababa, Ethiopia

Background

RDW is critical to the clinical diagnosis and progression of ESRD. There is currently little data on the relationship between RDW and ESRD in sub-Saharan Africa. Because of this, the present study evaluates RDW in patients with ESRD and associated factors in Addis Ababa, Ethiopia.

Methods

The hospital-based cross-sectional study design was conducted on a total of 83 patients. RDW, MCV, SCR, BUN, GFR, FBS and serum albumin were determined. Blood pressure (mmHg), weight (kg), height (m), MUAC (cm) and BMI (kg/m2) were also measured. Data entry was via Epi-data version 3.4 and analyzed with SPSS version 26.0. A multivariate logistic regression analysis with a p-value < 0.05 at a 95% confidence interval was used to identify the associated factors of RDW.

Results

A total of 83 ESRD patients participated, with a response rate of 95.4%. RDW ranged from 15.5% to 23.6% with a mean of 17.40% + 1.46%. Anisocytosis was present in 98.8% of patients. Of 83 patients, 66.3% were hypertensive, 20.5% had diabetes, and the remaining 13.3% had other conditions (glomerulonephritis and peripheral vascular disease). The mean GFR value was 5.20 mL/min/1.73 + 1.58. RDW showed a significant association with GFR (AOR: 4.6, 95% CI [1.27, 20.74], P = 0.047), alcohol consumption (AOR: 13.4, P = 0.012, 95% CI [1.97, 22.62]), recurrent kidney disease (AOR=25.6, P=0.016, 95% CI [1.85, 53.71]) and use of medication (AOR=00.2, P=0.044), 95% CI [0.03, 0.95]).

Conclusion

RDW showed a significant association with GFR, recurrent kidney disease, alcohol consumption, and medication use in hemodialysis-dependent ESRD patients. The mechanisms of RDW disruption in ESRD patients need further investigation.

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.

Red Blood Cell Distribution Width Is Associated With Adverse Kidney Outcomes in Patients With Chronic Kidney Disease

Background

Chronic kidney disease (CKD) is a global public health issue. Red blood cell distribution width (RDW) is a recently recognized potential inflammatory marker, which mirrors the variability in erythrocyte volume. Studies indicate that elevated RDW is associated with increased risk of mortality in CKD patients, while evidence regarding the impact of RDW on kidney outcome is limited.

Methods

Altogether 523 patients with CKD stage 1-4 from a single center were enrolled. We identified the cutoff point for RDW level using maximally selected log-rank statistics. The time-averaged estimated glomerular filtration rate (eGFR) slope was determined using linear mixed effects models. Rapid CKD progression was defined by an eGFR decline >5 ml/min/1.73 m²/year. The composite endpoints were defined as doubling of serum creatinine, a 30% decline in initial eGFR or incidence of eGFR < 15 ml/min/1.73 m², whichever occurred first. Multivariable logistic regression or Cox proportional hazards regression was performed, as appropriate.

Results

During a median follow-up of 26 [interquartile range (IQR): 12, 36] months, 65 (12.43%) patients suffered a rapid CKD progression and 172 (32.89%) composite kidney events occurred at a rate of 32.3/100 patient-years in the high RDW group, compared with 14.7/100 patient-years of the remainder. The annual eGFR change was clearly steeper in high RDW group {-3.48 [95% confidence interval (CI): -4.84, -2.12] ml/min/1.73 m²/year vs. -1.86 [95% CI: -2.27, -1.45] ml/min/1.73 m²/year among those with RDW of >14.5% and ≤14.5%, respectively, P for between-group difference <0.05}. So was the risk of rapid renal function loss (odds ratio = 6.79, 95% CI: 3.08-14.97) and composite kidney outcomes (hazards ratio = 1.51, 95% CI: 1.02-2.23). The significant association remained consistent in the sensitivity analysis.

Conclusion

Increased RDW value is independently associated with accelerated CKD deterioration. Findings of this study suggest RDW be a potential indicator for risk of CKD progression.

Impact of red cell distribution width and red cell distribution width/albumin ratio on all-cause mortality in patients with type 2 diabetes and foot ulcers: a retrospective cohort study

Background

Red blood cell distribution width (RDW) has emerged as a prognostic factor for mortality in various diseases. Up to now, few studies have focused on the prognostic value of RDW in patients with diabetic foot ulcers (DFUs). This retrospective cohort study aimed to investigate the impact of RDW and RDW/albumin (ALB) ratio on all-cause mortality in patients with DFUs.

Methods

This study included 860 patients with DFUs in a tertiary academic hospital. The associations of RDW and RDW/ALB with all-cause mortality were assessed by multivariable cox regression analyses. The pairwise comparisons of receiver operating characteristic (ROC) curves were performed to compare the predictive performance of RDW and RDW/ALB ratio. Harrell’s concordance index, integrated discrimination improvement, and net reclassification improvement were used to estimate the improvements in risk discrimination.

Results

Patients with high RDW and RDW/ALB had lower overall survival rates (all P < 0.001). The multivariable Cox regression revealed that high RDW [adjusted hazard ratio (HR) 2.426, 95% confidence interval (CI): 1.557–3.778, P < 0.001] and high RDW/ALB (adjusted HR 2.360, 95% CI: 1.414–3.942, P = 0.001) were independent associated with high all-cause mortality. In subgroup analyses, the comparative analysis of ROC curves revealed that the discriminating ability of the RDW/ALB ratio was significantly superior to RDW in patients with no severe DFUs or no severe peripheral artery disease, or in young and middle-aged patients (all P < 0.05). Adding RDW and RDW/ALB ratio to base models improved discrimination and risk reclassification for all-cause mortality.

Conclusions

RDW and RDW/ALB ratio are robust and independent prognostic markers in patients with DFUs. The RDW/ALB ratio appears to be of more predictive value for mortality in younger and less severely ill patients with DFUs. Both RDW and RDW/ALB ratio can provide incremental predictive value for all-cause mortality over traditional risk factors. RDW and RDW/ALB ratio can be used to identify high-risk patients with DFUs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01534-4.

The combined clinical impact of red blood cell distribution width and vascular calcification on cardiovascular events and mortality in patients with end-stage kidney disease

Background

Little is known about how the interaction between red blood cell distribution width (RDW) and vascular calcification (VC) affects cardiovascular (CV) events and mortality in end-stage kidney disease (ESKD) patients. This study investigated the combined prognostic effect of RDW and VC in ESKD patients starting dialysis.

Methods

A retrospective single-center study of 582 ESKD patients was conducted. VC was assessed by calculating the aortic calcification index (ACI) using computed tomography. Patients were divided into low ACI-low RDW, low ACI-high RDW, high ACI-low RDW, and high ACI-high RDW groups based on median ACI (17.12) and RDW (14.3) values. The association between RDW and VC and the composite endpoint of CV events and death was analyzed.

Results

During a median follow-up of 3.1 years (range, 1.5–5.5 years), 165 CV events (28.4%) and 124 deaths (21.4%) occurred. Cox regression showed that the low ACI-high RDW (adjusted hazard ratio [HR], 1.66; 95% confidence interval [CI], 1.04–2.66; p = 0.03) and high ACI-low RDW (adjusted HR, 1.95; 95% CI, 1.21–3.14; p = 0.006) groups had a greater risk of CV events and death than the low ACI-low RDW group. The high ACI-high RDW group had the greatest risk (adjusted HR, 2.23; 95% CI, 1.42–3.52; p = 0.001). The effect of the interaction between ACI and RDW on CV events and mortality was statistically significant (p = 0.005).

Conclusion

High RDW and VC interact to increase the risk of CV events and death in ESKD patients.

Role of red blood cell distribution width, as a prognostic indicator in COVID-19: A systematic review and meta-analysis

The red blood cell distribution width (RDW), an indicator of anisocytosis has emerged as a potential tool for risk stratification of critically ill patients with sepsis. Prognostic predictors are of paramount interest for prompt intervention and optimal utilization of the healthcare system in this ongoing context of the Coronavirus Disease 2019 (COVID-19) pandemic. The current systematic review and meta-analysis aims to explore the utility of RDW in the prognosis of COVID-19 patients. A comprehensive screening of electronic databases was performed up to 30th April 2021 after enrolling in PROSPERO (CRD42020206685). Observational studies or interventional studies, evaluating the impact of RDW in COVID-19 outcomes (mortality and severity) are included in this meta-analysis.Our search retrieved 25 studies, with a total of 18,392 and 3,446 COVID-19 patients for mortality and disease severity outcomes. Deceased and critically ill patients had higher RDW levels on admission in comparison to survivors and non-severe patients (SMD = 0.46; 95%CI 0.31-0.71; I2  = 88% and SMD = 0.46; 95%CI 0.26-0.67; I2  = 60%, respectively). In a sub-group analysis of 2,980 patients, RDW > 14.5 has been associated with increased risk of mortality (OR = 2.73; 95%CI 1.96-3.82; I2  = 56%). However, the evidences is of low quality. A higher level of RDW on admission in COVID-19 patients is associated with increased morbidity and mortality. However, further studies regarding the cut-off value of RDW are the need of the hour.

Ferric citrate hydrate is associated with a reduced cost of drugs and a smaller change in red blood cell distribution width

The ASTRIO study was a randomised, multicentre, 24-week study that compared the effects of ferric citrate hydrate (FC) and non-iron-based phosphate binders (control) on anaemia management in haemodialysis (HD) patients receiving erythropoiesis-stimulating agents (ESAs). In that study, FC reduced the doses of ESAs and intravenous iron without affecting haemoglobin (Hb); however, the cost-effectiveness of FC was unclear. We retrospectively implemented a cost-effectiveness analysis comparing the incremental cost-effectiveness ratios (ICERs) in FC (n = 42) and control (n = 40) groups in patients with serum phosphate and Hb controlled within the ranges of 3.5–6.0 mg/dL and 10–12 g/dL, respectively. Costs included drug costs of phosphate binders, ESAs, and intravenous iron. Elevated red cell distribution width (RDW) has been reported to be associated with mortality in HD patients and was therefore used as an effectiveness index. The mean (95% confidence interval) differences in drug costs and RDW between the FC and control groups were US$ − 421.36 (− 778.94 to − 63.78, p = 0.02) and − 0.83% (− 1.61 to – 0.05, p = 0.04), respectively. ICER indicated a decrease of US$ 507.66 per 1% decrease in RDW. FC was more cost-effective than non-iron-based phosphate binders. Iron absorbed via FC could promote erythropoiesis and contribute to renal anaemia treatment.

Association between red blood cell distribution width and non-valvular atrial fibrillation in hemodialysis patients: a single-center Chinese population study

Background

Red blood cell distribution width (RDW) has emerged as a prognostic marker of atrial fibrillation (AF) in various clinical settings. However, the relationship by which RDW was linked to AF in hemodialysis (HD) patients was not clear. We sought to reveal the relationship between RDW and AF occurrence in HD patients.

Methods

We enrolled 170 consecutive maintenance HD patients, including 86 AF patients and 84 non-AF patients. All participants’ medical history and detailed clinical workup were recorded before the first dialysis session of the week. Electrocardiography, laboratory and transthoracic echocardiography examination indices were compared between the AF group and non-AF group. Multivariable logistic regression analysis was performed to identify the independent predictors of AF occurrence in HD patients.

Results

There were all paroxysmal AF patients in AF group. Compared to the non-AF group, patients with AF group had a significantly older age (61.0 ± 1.48 vs. 49.71 ± 1.79, p < 0.001), lower BMI (24.3 ± 4.11 vs. 25.8 ± 3.87, p < 0.05), higher RDW (15.10 ± 0.96 vs. 14.26 ± 0.82, p < 0.001) and larger LAD (39.87 ± 3.66 vs. 37.68 ± 5.08, p < 0.05). Multivariable logistic regression analyses demonstrated that values of age (OR: 1.030, 95%CI: 1.004-1.057, per one- year increase), BMI (OR: 0.863, 95%CI: 0.782–0.952, per 1 kg/m² increase), RDW (OR: 2.917, 95%CI: 1.805–4.715, per 1% increase) and LAD (OR: 1.097, 95%CI: 1.004–1.199, per 1 mm increase) were independently associated with AF occurrence (p < 0.05, respectively). The best cutoff value of RDW to predict AF occurrence was 14.65% with a sensitivity of 68.6% and a specificity of 72.6%.

Conclusions

The increased RDW was significantly associated with the paroxysmal AF occurrence in HD patients.

Monthly Continuous Erythropoietin Receptor Activator Versus Weekly Epoetin-Beta, Similar Hemoglobinization but Different Anisocytosis Degree in Hemodialysis Patients: A Randomized Controlled Trial

Background

The monthly continuous erythropoietin receptor activator (CERA) utilization maintains stable hemoglobin (Hb) after conversion from weekly epoetin-β (EB); however, how the different pharmacologic properties affect the red blood cell (RBC) size determined by RBC distribution width (RDW) has not been evaluated yet. We assess the potential differences in iron metabolism, plasma erythropoietin (EPO), hepcidin, and soluble α-Klotho (α-Klotho) levels as an emergent hematopoiesis factor.

Methods

Thirty-seven chronic hemodialysis patients were included from January 2010 to November 2011 and randomized (1:1) to continue with EB or to convert to monthly CERA. Primary outcome was the mean change in Hb between groups at months 0, 3 and 6, and the percentage of patients who maintained stable Hb (Hb ± 1 g/dL from baseline level to month 6). Secondary outcomes were the influence on the erythropoietic process and iron metabolism markers. Thirty-one patients completed the study (CERA: n = 15, EB: n = 16).

Results

The mean (95% confidence interval (CI)) Hb difference between groups was 0.28 g/dL (-0.36 to 0.93). There was no difference between the percentages of patients with stable Hb levels. In the CERA group RDW values increased progressively (interaction erythropoietin-stimulating agent (ESA) type and time on RDW values, F (1.57, 45.60) = 17.17, P < 0.01, partial η² = 0.37) and the mean corpuscular volume changed at the different time points, (F (2, 28) = 29.12, P = 0.03, partial η² = 0.23). During the evaluation period, in the CERA group, EPO was higher, and hepcidin and ferritin decreased significantly. α-Klotho decreased in both groups and correlated negatively with the changes on the RDW and positively with transferrin and serum iron. The number of serious adverse events was higher at the CERA group.

Conclusions

Monthly CERA maintained Hb concentrations; however, it showed a significant effect on RDW, probably due to its impact on the EPO and hepcidin levels. α-Klotho decreased significantly in both groups, and its changes correlated with the changes in iron metabolism. Whether the RDW evolution was associated with the serious adverse events (SAEs) is a feasible hypothesis that needs to be confirmed in large studies.

Nutritional Status Associated to Red Cell Distribution Width, Length of Stay, and Clinical Outcome patient with Chronic Kidney Diseases

INTRODUCTION: Red cell distribution width (RDW) shows the heterogeneity of erythrocyte size associated with inflammation and various clinical conditions including in patients with chronic kidney disease (CKD). Systemic inflammation and oxidative stress were commonly found in CKD patients. AIM: This study aimed to examine the relationship of nutritional status, length of hospital stay (LOS), and clinical outcome to RDW in CKD patients. METHODS: We conducted a retrospective cohort study of 1736 patients CKD patients who admitted from January 2017 to August 2020, aged between 18 and 60 years and were hospitalized at Wahidin General Hospital. From those, 239 were consulted with clinical nutrition specialist, of which 59 patients eligible with the criteria inclusion. Data were collected through medical records and through electronic data (biochemical data). RDW was categorized into normal and high RDW group, nutritional status based on subjective global assessment (SGA), LOS <10 days and clinical outcome based on conditions at the time of hospital discharged. Data were analyzed using SPSS version 25.0. RESULTS: The data of 59 patients were analyzed, the mean age was 50.42 years (normal RDW) and 47.24 years (high RDW), most of them are women (57.7% vs. 60.6%). There were 42 patients with moderate malnutrition (23 normal RDW and 19 high RDW) and 17 patients with severe malnutrition (3 normal RDW and 14 with high RDW). The study found a significant differences between normal RDW and high RDW (p 0.021), but not significant differences in LOS (p 0.890) and clinical outcome (p 0.968). There were a significant differences in the levels of hemoglobin (p = 0.001), RBG (p = 0.030), and serum sodium level (p = 0.010). Patient with LOS < 10 days had lower sodium levels and more severe anemia when compared with LOS > 10 days and the poor clinical outcome had a heavier degree of anemia compared to the good clinical outcomes. CONCLUSION: Poor nutritional status was associated with an increase in RDW, degree of anemia, and sodium level.

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 as a predictor of mortality among patients regularly visiting the nephrology outpatient clinic

The association between increased red blood cell distribution width (RDW) and mortality among patients treated on an outpatient basis in the nephrology outpatient clinic is unclear. Therefore, our study aimed to investigate the association between baseline and time-averaged RDW and mortality risk in patients treated in our nephrology outpatient clinic. Our multi-center retrospective analysis was based on data of 16,417 outpatient nephrology patients with available baseline renal function and RWD values. The median baseline RDW was 13.0% (range, 10.0–32.1%). The high-RDW group was defined as the top quartile (≥ 13.8%, n = 4302). The crude mortality rate was 15.0% (n = 1806) at a median follow-up of 127.5 months. From the results of the multivariate Cox proportional hazards regression model adjusted for covariates, including eGFR, hemoglobin, and factors of anemia treatment, patients with a high time-averaged RDW had increased mortality risk (adjusted hazard ratio, 1.505; 95% confidence interval, 1.326–1.708; P < 0.001), irrespective of sex, presence of anemia, and chronic kidney disease, except in individuals aged < 45 years. Thus, increased baseline and time-averaged RDW were significantly associated with increased mortality in patients aged > 45 years treated on an outpatient basis in the nephrology clinic.

Usefulness of red cell distribution width to predict mortality in patients undergoing endovascular repair of abdominal aortic aneurysms

BACKGROUND

Red cell distribution width (RDW) reflecting impaired erythropoyesis, has been associated with poor prognosis and mortality in several conditions. The aim of this study was to determine the relationship between RDW and the 5-year survival after the endovascular repair of abdominal aortic aneurysms (EVAR) and its ability to improve the discriminative power of a survival predictive score.

METHODS

Retrospective analysis of 284 patients undergoing EVAR at a single centre. The pattern of relationship between RDW and survival was assessed with penalized smoothing splines. Categorized RDW values were added to a predictive score based in standard preoperative variables, whose improvement in discriminative power was calculated on the basis of changes in the C-statistics and the continuous Net Reclassification Index (c-NRI).

RESULTS

The survival rate at 5 years was 66.2% and was independently associated with hemoglobin (HR=0.85,p<0.004), statin intake (HR=0.54,p<0.004), heart failure (HR=2.53,p<0.018), atrial fibrillation (HR=2.53,p<0.000) and the non-revascularized coronary artery disease (HR=2.15, p<0.005). The relationship between RDW values and 5-year survival was linear. RDW-CV and RDW-SD were categorized to cut-off values of ≥15% (n=83,29.2%) and ≥50 fL (n=82, 28.9%) that were independently associated with poorer 5-year survival rates (HR=2.03,CI95%=1.29-3.19,p=0.002 and HR=1.89, CI95%=1.21-2.95,p=0.005, respectively). The addition of the RDW CV or the RDW-SD to the baseline predictive score significantly improved the c-NRI (0.437,p<0.001 and 0.442,p<0.001, respectively).

CONCLUSIONS

High preoperative RDW levels were linear and adversely related to 5-year survival after EVAR, improved the discriminative power of a predictive score based in standard preoperative variables and may help in decision-making at the time of surgical planning.

Red blood cell distribution width predicts residual renal function decline in patients undergoing continuous ambulatory peritoneal dialysis

To investigate the relationship between red blood cell distribution width (RDW) and residual renal function (RRF) in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Seventy-seven CAPD patients were enrolled in this study. According to receiver operator characteristic (ROC) curve analysis, patients were divided into high RDW (RDW > 14.95%) and low RDW (RDW ≤ 14.95%) groups. The data of baseline clinical, biochemical parameters, comorbidities, medication status, peritoneal function, and dialysis adequacy were compared. Survival curves were calculated using Kaplan-Meier method. Cox regression model was employed to analyze risk factors of decline in RRF. The overall median survival time was 24 months, the median survival time of high RDW group (46 patients) and low RDW group (31 patients) were 24 and 12 months, respectively. Compared with the low RDW group, patients in the high RDW group were older, higher rate of decline RRF and white blood cells count as well as lower total Kt/V (all p < 0.05). Kaplan-Meier survival curves showed that the low RDW group had higher survival of RRF compared with the high RDW group (p < 0.001). Multivariate Cox regression analysis showed that high RDW was independent risk factor for decline of RRF(hazard ratio = 1.441, 95% confidence interval: 1.089-1.905, p = 0.01). Increased baseline RDW is associated with decline of RRF in CAPD patients and RDW can be stratified as a valuable indicator for the risk of RRF decline.

Identifying key predictors of mortality in young patients on chronic haemodialysis-a machine learning approach

BACKGROUND

The mortality risk remains significant in paediatric and adult patients on chronic haemodialysis (HD) treatment. We aimed to identify factors associated with mortality in patients who started HD as children and continued HD as adults.

METHODS

The data originated from a cohort of patients <30 years of age who started HD in childhood (≤19 years) on thrice-weekly HD in outpatient DaVita dialysis centres between 2004 and 2016. Patients with at least 5 years of follow-up since the initiation of HD or death within 5 years were included; 105 variables relating to demographics, HD treatment and laboratory measurements were evaluated as predictors of 5-year mortality utilizing a machine learning approach (random forest).

RESULTS

A total of 363 patients were included in the analysis, with 84 patients having started HD at <12 years of age. Low albumin and elevated lactate dehydrogenase (LDH) were the two most important predictors of 5-year mortality. Other predictors included elevated red blood cell distribution width or blood pressure and decreased red blood cell count, haemoglobin, albumin:globulin ratio, ultrafiltration rate, z-score weight for age or single-pool Kt/V (below target). Mortality was predicted with an accuracy of 81%.

CONCLUSIONS

Mortality in paediatric and young adult patients on chronic HD is associated with multifactorial markers of nutrition, inflammation, anaemia and dialysis dose. This highlights the importance of multimodal intervention strategies besides adequate HD treatment as determined by Kt/V alone. The association with elevated LDH was not previously reported and may indicate the relevance of blood-membrane interactions, organ malperfusion or haematologic and metabolic changes during maintenance HD in this population.

Red blood cell distribution width and peritoneal dialysis-associated peritonitis prognosis

Objective

Red blood cell distribution width (RDW) is a parameter of the heterogeneity of circulating erythrocyte size. Recent researches have pointed out a link among RDW, chronic kidney disease, and inflammation. We sought to investigate the prognostic value of baseline RDW in patients with peritoneal dialysis-associated peritonitis (PDAP).

Methods

Our study included 337 peritonitis episodes experienced by 202 patients who were undergoing continuous ambulatory peritoneal dialysis (CAPD) at a single center from 2013 to 2018. Episodes were categorized according to the tertiles of baseline RDW levels (T1, <13.2%; T2, 13.2−14.3%; T3, >14.3%). Routine logistic regression and generalized estimating equation (GEE) were used to estimate the association between RDW and treatment failure, which was defined as relapse/recurrent episodes, catheter removal, or death during therapy.

Results

After adjusting for other potential predictors, RDW exhibited an incremental relationship with the risk of treatment failure. The baseline RDW of T3 indicated a 43% and 52% increased venture of treatment failure in logistic and GEE analyses, respectively, compared with T1. As a continuous variable, the fitting curve based on restricted cubic spiline showed that the relationship was nonlinearly but positively correlated. The multivariate model A (combined RDW with baseline age, albumin, serum ferritin, and duration on CAPD) showed an area under the curve of 0.671 (95% confidence interval, 0.5920.749) for the prediction of treatment failure.

Conclusions

A Higher baseline level of RDW was significantly associated with a greater rate of treatment failure among PDAP episodes independent of other potential predictors.

Red Blood Cell Distribution Width and Neutrophil-to-Lymphocyte Ratio in Predicting Adverse Outcomes of Acute Kidney Injury in Hospitalized Patients

Background

Acute kidney injury (AKI) is a common clinical condition with high morbidity and mortality. Early risk stratification by identifying patients at risk for death or dialysis requirement has important therapeutic implications for timely interventions.

Objective

The aim of this study was to examine the association of routine blood test parameters, specifically red blood cell distribution width (RDW) and neutrophil-to-lymphocyte ratio (NLR), with the AKI patient outcomes.

Methods

All adult patients hospitalized from January 1, 2016, to June 30, 2016, in the Second Xiangya Hospital of Central South University were surveyed. Demographic characteristics, laboratory measurements, comorbidities, and outcomes of a total of 1,188 adult AKI patients were analyzed.

Results

The incidence of AKI was 1.8% (1,188/65,329). The all-cause mortality was 16.0% (190/1,188). The multivariable relative risk of AKI mortality comparing high RDW with low RDW was 1.84 and the risk comparing high NLR with low NLR was 2.54. RDW and NLR combination showed additive values in stratifying high-risk patients, and the predictive power was comparable to the use of serum creatinine for staging AKI. In subgroup analyses, high RDW predicted prerenal AKI mortality better than intrinsic AKI. High RDW and NLR also independently predicted renal replacement therapy (RRT) requirement in AKI patients. In contrast, WBC count and platelet-to-lymphocyte ratio did not show obvious correlations with death and RRT requirement in AKI patients.

Conclusion

The results support the potential usefulness of RDW and NLR in risk stratification of AKI patients, providing additional prognostic information for treatment and supportive care.

Clinical Utility of Red Cell Distribution Width in Patients with Pleural Effusion

BACKGROUND

The red cell distribution width (RDW) value has been recently recognized as a valuable biomarker in clinical practice. The RDW value has not been evaluated so far in patients with pleural effusion. Thus, this study aimed to investigate whether RDW could distinguish between exudative and transudative pleural effusions.

MATERIALS AND METHODS

We measured protein and lactate dehydrogenase levels on both pleural fluids and serum samples from 223 cases and classified them as transudates or exudates based on the classic Light's criteria. We collected blood cell count elements such as RDW from the medical records. We also investigated the correlation between RDW and the nature of pleural effusion.

RESULTS

In 55.2% of the patients, pleural fluid was exudative. Although we found no significant association between RDW and the nature of the pleural fluid, we detected a significantly higher amount of RDW (14.9 ≤) in patients with exudative pleural effusion compared to transudate (66.7% vs. 33.3%; P= 0.01). In this category, neoplastic conditions were mostly observed in the patients (76.3%), followed by pulmonary thromboembolism (21.1%) and systemic lupus erythematous (2.6%).

CONCLUSION

The findings could not reveal any noticeable correlation between RDW and the Light criteria. However, it appears that elevated RDW levels give insights into the valuable nature of RDW in different conditions such as neoplastic diseases.

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.

Hematological Parameters and Clinical Features in Patients with Advanced Chronic Kidney Disease

Background

Hematological parameters like red cell distribution width (RDW) and mean platelet volume (MPV) were reported to be associated with inflammation, atherosclerosis, and chronic kidney disease (CKD) progression. In this study, we evaluated RDW and MPV along with clinical features in patients with advanced CKD. We also aimed to detect clues for causative relations concerning these parameters, renal function and comorbidities.

Methods

Stage 3-5 CKD patients (627 total) were included (mean age 63.1 years, 48.3% male). Patients with malignancies, cirrhosis, infections, severe anemia, and systemic inflammation were excluded. Patients were evaluated for clinical features and grouped for comparison using median RDW and MPV. Linear regression models were generated to predict potential influences on RDW and MPV.

Results

Mean estimated glomerular filtration rate (eGFR) was 27.3 mL/min/1.73m². Mean Charlson Comorbidity Index (CCI) score was 5.83 ± 2.06. Patients with high RDW (n = 303) were older with higher CRP and CCI, they also had lower eGFR, hemoglobin, and albumin (P < 0.001 for all). Patients with low MPV (n = 311) had lower eGFR, and platelet counts (P = 0.015 and 0.017). eGFR was negatively correlated with RDW after adjusting for age, gender and comorbidities. In a further adjusted model RDW was associated with CRP, CCI, hemoglobin and albumin (P < 0.05 for all), not with eGFR. MPV was positively correlated with eGFR in our adjusted, and fully adjusted regression models (P = 0.003).

Conclusion

In this study, we found that high RDW is associated with comorbidity burden, anemia, and inflammatory status in patients with advanced CKD. Meanwhile, low MPV seems to be associated with worse renal function.

Low rather than high mean corpuscular volume is associated with mortality in Japanese patients under hemodialysis

Recent studies have reported that high mean corpuscular volume (MCV) might be associated with mortality in patients with advanced chronic kidney disease (CKD). However, the question of whether a high MCV confers a risk for mortality in Japanese patients remains unclear. We conducted a longitudinal analysis of a cohort of 8571 patients using data derived from the Japan Dialysis Outcomes and Practice Patterns Study (J-DOPPS) phases 1 to 5. Associations of all-cause mortality, vascular events, and hospitalization due to infection with baseline MCV were examined via Cox proportional hazard models. Non-linear relationships between MCV and these outcomes were examined using restricted cubic spline analyses. Associations between time-varying MCV and these outcomes were also examined as sensitivity analyses. Cox proportional hazard models showed a significant association of low MCV (< 90 fL), but not for high MCV (102 < fL), with a higher incidence of all-cause mortality and hospitalization due to infection compared with 94 ≤ MCV < 98 fL (reference). Cubic spline analysis indicated a graphically U-shaped association between baseline MCV and all-cause mortality (p for non-linearity p < 0.001). In conclusion, a low rather than high MCV might be associated with increased risk for all-cause mortality and hospitalization due to infection among Japanese patients on hemodialysis.

The problem with transferrin saturation as an indicator of iron 'sufficiency' in chronic kidney disease

After a brief review of physiological iron metabolism, we describe diagnostic tests for iron status and iron deficiency anemia in patients without chronic kidney disease (CKD) or inflammation. Thereafter we review the dysregulation of iron metabolism in CKD. Specific emphasis is placed on the role of the 'inflammatory' state that develops with the progression of CKD. It invokes changes in iron metabolism that are the exact opposite of those occurring during pure iron deficiency. As a result, transferrin saturation (TSAT) becomes a poorer index of iron availability to the bone marrow and serum ferritin no longer represents iron that can be used during erythropoiesis. We argue that serum iron may provide more information to guide iron therapy than TSAT. In other words, the emphasis on TSAT is misplaced. With the development of a number of hypoxia-inducible factor prolyl hydroxylase inhibitors, which restore iron metabolism toward the 'physiologic state', the iron indices indicating sufficient iron availability to avoid functional iron deficiency during therapy of CKD-associated anemia are likely to change. We summarize these changes in the section 'A peek into things to come!', citing the available data.

Red blood cell distribution width predicts long-term mortality in critically ill patients with acute kidney injury: a retrospective database study

Acute kidney injury (AKI) is a serious complication in the intensive care unit (ICU), which may increase the mortality of critically ill patients. The red blood cell distribution width (RDW) has proved useful as a predictor of short-term prognosis in critically ill patients with AKI. However, it remains unknown whether RDW has a prognostic value of long-term all-cause mortality in these patients. The data of 18279 critically ill patients with AKI at first-time hospital admission were extracted from the Medical Information Mart for Intensive Care III (MIMIC-III) database. The tertiles of the RDW values were used to divide subjects into three groups, namely RDW < 13.6% for the low RDW group, 13.6% ≤ RDW < 15.2% for the middle RDW group and RDW ≥ 15.2% for the high RDW group. Demographic data, mortality, 4-year survival time and severity scale scores were compared among groups. The Kaplan-Meier analysis and the Cox regression analysis were performed to assess the impact of RDW on all-cause mortality in AKI patients. The receiver operating characteristic (ROC) curve analysis was done to evaluate the prognostic value of RDW on the long-term outcome of critically ill patients with AKI. The median age of the enrolled subjects was 65.6 years. AKI patients with a higher RDW value had significantly shorter survival time and higher death rate. By the Kaplan-Meier analysis, patients in the higher RDW group presented significantly shorter survival time and higher death rate. The Cox regression model indicated RDW as an independent risk factor of all-cause mortality of AKI patients (HR 1.219, 95% CI, 1.211 to 1.228). By the ROC analysis, RDW appeared more efficient in predicting long-term prognosis as compared with conventional severity scales. The AUC of RDW (95% CI, 0.712 to 0.725) was significantly higher than other severity scale scores. In conclusion, RDW is positively correlated to survival time of 4-year follow-up in critically ill patients with AKI, and RDW is an independent prognostic factor of long-term outcomes of these patients.

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.

Red blood cell distribution width and mortality and hospitalizations in peritoneal dialysis patients

BACKGROUND

Red blood cell distribution width (RDW) is found to be associated with different types of anemia and has recently been studied as a prognostic marker of mortality in hemodialysis patients. However, the relationship of RDW with mortality and hospitalization rate in peritoneal dialysis (PD) patients is less known.

METHODS

Among 14 323 incident PD patients between 2007 and 2011 in the USA, we examined the relationship of baseline and time-varying RDW with the risk of mortality and time to first hospitalization using adjusted Cox models. In addition, we examined the relationship of baseline RDW and hospitalization rate using an adjusted negative-binomial regression model. Sensitivity analyses included competing risk models and subgroup analyses.

RESULTS

The study population comprised patients 56 ± 16 years of age, including 43% females, 23% African Americans and 62% diabetics, with a mean RDW of 15.3 ± 1.6%. In models adjusted for clinical characteristics and laboratory parameters, RDW exhibited an incremental relationship with the mortality risk, where RDW ≥16.5% had a 40% and 69% higher risk of death in baseline and time-varying analyses, respectively, compared with an RDW of 14.5-15.5%. Moreover, higher baseline RDW ≥16.5% was also associated with a higher risk of time to first hospitalization {hazard ratio 1.22 [95% confidence interval (CI) 1.14-1.29]} and a higher rate of hospitalizations [incidence rate ratio 1.16 (95% CI 1.09-1.23)]. These results were consistent across numerous sensitivity analyses.

CONCLUSIONS

Higher RDW is associated with a higher risk of mortality and hospitalizations among incident PD patients. Further studies are needed to examine the mechanism behind RDW and adverse outcomes.

Identifying risk groups of infectious spondylitis in patients with end-stage renal disease under hemodialysis: a propensity score-matched case-control study

BACKGROUND

Patients with end-stage renal disease (ESRD) under hemodialysis (HD) are at greater risks of infectious spondylitis (IS), but there is no reliable predictor that facilitate early detection of this relatively rare and insidious disease.

METHODS

A retrospective review of the medical records from patients with ESRD under HD over a 12-year period was performed at a tertiary teaching hospital, and those with a first-time diagnosis of IS were identified. A 1:4 propensity score-matched case-control study was carried out, and baseline characteristics, underlying diseases, and laboratory data were compared between the study group and the control group, one month before the date of diagnosis or the index date respectively.

RESULTS

A total of 16 patients with IS were compared with 64 controls. After adjustment, recent access operation (odds ratio [OR], 13.27; 95% confidence interval [CI], 3.53 to 49.91; p <  0.001), degenerative spinal disease (OR, 12.87; 95% CI, 1.89 to 87.41; p = 0.009), HD through a tunneled cuffed catheter (OR, 6.75; 95% CI, 1.74 to 26.14; p = 0.006), low serum levels of hemoglobin, albumin, as well as high levels of red blood cell volume distribution width (RDW), alkaline phosphatase (ALP), and high sensitivity C-reactive protein were significant predictors for a IS diagnosis one month later. Receiver operating characteristic curves for hemoglobin, RDW, ALP, and albumin all showed good discrimination. The further multivariate models identified both high serum ALP levels and low serum RDW levels following a recent access intervention in patients with relatively short HD vintages may be indicative of the development of IS.

CONCLUSION

Patients under HD with relatively short HD vintages showing either elevated ALP levels or low RDW levels following a recent access intervention should prompt clinical awareness about IS for timely diagnosis.

Randomised clinical trial of ferric citrate hydrate on anaemia management in haemodialysis patients with hyperphosphataemia: ASTRIO study

Ferric citrate hydrate (FC) is an iron-based phosphate binder approved for hyperphosphataemia in patients with chronic kidney disease. We conducted a randomised controlled trial to evaluate the effects of FC on anaemia management in haemodialysis patients with hyperphosphataemia. We 1:1 randomised 93 patients who were undergoing haemodialysis and being treated with non-iron-based phosphate binders and erythropoiesis-stimulating agents (ESA) to receive 24 weeks of FC or to continue their non-iron-based phosphate binders (control) in a multicentre, open-label, parallel-design. Phosphate level was controlled within target range (3.5–6.0 mg/dL). The primary endpoint was change in ESA dose from baseline to end of treatment. Secondary endpoints were changes in red blood cell, iron and mineral, and bone-related parameters. Compared with control, FC reduced ESA dose [mean change (SD), −1211.8 (3609.5) versus +1195 (6662.8) IU/week; P = 0.03] without significant differences in haemoglobin. FC decreased red blood cell distribution width (RDW) compared with control. While there were no changes in serum phosphate, FC reduced C-terminal fibroblast growth factor (FGF) 23 compared with control. The incidence of adverse events did not differ significantly between groups. Despite unchanged phosphate and haemoglobin levels, FC reduced ESA dose, RDW, and C-terminal FGF23 compared with control.

Factors responsible for cerebral hypoxia in hemodialysis population

Brain tissue oxygenation (rSO(2)) measured by near-infrared spectroscopy (NIRS) is lower in hemodialysis patients than in the healthy population and is associated with cognitive dysfunction. The involved mechanisms are not known. We conducted this study to identify the factors that influence the rSO2 values in end-stage renal disease (ESRD) patients and to describe rSO2 changes during hemodialysis. We included a cohort of ESRD patients hemodialyzed in our institution. We recorded rSO2 using INVOS 5100C oximetry system (Medtronic, Essex, U.K.) and analyzed changes in basic laboratory values and hemodynamic fluctuations. Baseline rSO2 was lower in patients with heart failure (45.2±8.3 % vs. 54.1±7.8 %, p=0.006) and was significantly linked to higher red cell distribution width (RDW) (r=-0.53, p?0.001) and higher BNP level (r=-0.45, p=0.01). The rSO(2) value decreased in first 15 min of hemodialysis, this decrease correlated with drop in white blood count during the same period (r=0.43, p=0.02 in 10 min, r=0.43, p=0.02 in 20 min). Lower rSO(2) values in patients with heart failure and higher RDW suggest that hemodynamic instability combined with vascular changes probably leads to worse cerebral oxygenation in these patients. Decrease of rSO(2) in 15th minute of hemodialysis accompanied with a significant drop in leukocyte count could be explained by complement activation.

Anisocytosis predicts postoperative renal replacement therapy in patients undergoing heart valve surgery

BACKGROUND

Acute kidney injury (AKI) is one of the serious postoperative complications in patients undergoing heart valve surgery. The aim of the present study was to identify selected biomarkers to predict AKI requiring renal replacement.

METHODS

A prospective study was conducted on a group of 751 patients undergoing heart valve surgery. The data on risk factors, preoperative complete blood count, course of operations and postoperative period was assessed. The primary endpoint at the 30-day follow-up was postoperative AKI requiring renal replacement therapy. The secondary end-point was death from all causes in patients with postoperative AKI requiring renal replacement.

RESULTS

The primary endpoint occurred in 46 patients. At multivariate analysis: age, red cell distribution width (RDW) and C-reactive protein remained independent predictors of the primary endpoint. Hemoglobin and RDW were associated with an increased risk of death.

CONCLUSIONS

Elevated RDW is associated with a higher risk of postoperative AKI and death in patients with AKI.

Usefulness of RBC distribution width and C-reactive protein to predict mortality in pediatric non-cardiac critical illness

INTRODUCTION

We aimed to assess the performance of red blood cell distribution width (RDW), C-reactive protein (CRP) or the combination of both to predict clinical outcomes in pediatric non-cardiovascular critical illness.

MATERIALS AND METHODS

We analyzed 404 pediatric non-cardiovascular critically ill patients admitted to pediatric intensive care unit (PICU). Potential predictors were identified using multivariable logistic regression. We also calculated the power of RDW and CRP additive to pediatric critical illness score (PCIS) to predict mortality with calculation of C-index value, integrated discrimination improvement (IDI) and net reclassification improvement (NRI) indices.

RESULTS

RDW and CRP independently predicted PICU mortality. The C-index value of PCIS with respect to prediction of PICU mortality was greater than that of RDW and CRP. The combination of RDW or CRP or both with PCIS did significantly increase C-index value for predicting mortality (all p < 0.01). Addition of RDW or CRP or their combination to PCIS provided IDI of 7%, 1.1% and 9.4% (p = 0.009, 0.01 and 0.003) and NRI of 15.9%, 13.1% and 19.6% (p = 0.002, 0.043 and 0.002), respectively.

CONCLUSIONS

In pediatric non-cardiovascular critically ill patients, RDW and CRP could serve as independent predictors of PICU mortality and addition of RDW or CRP or both to PCIS significantly improves the ability to predict PICU mortality.

Mean Corpuscular Volume and Mortality in Incident Hemodialysis Patients

BACKGROUND/AIMS

Anemia is common in patients with advanced chronic kidney disease (CKD). A proportion of patients present with macrocytic anemia, manifested by elevated mean corpuscular volume (MCV), which has been associated with worse outcomes in CKD patients. However, it is unknown whether elevated MCV is associated with higher mortality risk in incident hemodialysis (HD) patients.

METHODS

This retrospective observational cohort study examined all-cause, cardiovascular, and infectious mortality associations with both baseline and time-varying MCV in 109,501 incident HD patients using Cox proportional hazards models with 3 levels of hierarchical multivariable adjustment. Odds ratios of high versus low baseline MCV were evaluated using logistic regression.

RESULTS

The mean age of patients was 65 ± 15 (standard deviation) years and the cohort was 44% female, 58% diabetic, and 31% African American. Higher MCV was associated with older age, female sex, non-Hispanic White race-ethnicity, alcohol consumption, and having a decreased albumin or protein intake. Patients with higher MCV levels (> 98 fL) had a higher all-cause, cardiovascular, and infectious mortality risk in both baseline and time varying models, and across all levels of adjustment. In the fully adjusted models, compared to a reference of MCV 92-< 94 fL, patients with a baseline MCV > 100+ fL had a 28% higher risk of all-cause mortality (hazard ratio [HR] 1.28, 95% CI 1.22-1.34), 27% higher risk of cardiovascular mortality (HR 1.27, 95% CI 1.18-1.36), and 18% higher risk of infectious mortality (HR 1.18, 95% CI 1.02-1.38). Associations of higher MCV with these adverse outcomes persisted across all examined subgroups of clinical characteristics.

CONCLUSIONS

Higher MCV was associated with higher all-cause, cardiovascular, and infectious mortality in HD patients. Further investigation is necessary to understand the underlying nature of the observed association.

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.

Low Cerebral Oxygenation Is Associated with Cognitive Impairment in Chronic Hemodialysis Patients

BACKGROUND/AIMS

High rates of cognitive impairment (CI) are an alarming problem in patients undergoing chronic hemodialysis (HD). Its pathophysiology remains unclear and there are indications that brain ischemia might be one of the key causes. Cerebral tissue oxygenation, as measured by near-infrared spectroscopy, is known to be decreased in HD patients. However, it is unknown whether CI is associated or not associated with lower cerebral oxygenation in these patients. The primary aim of our study was to probe this possible association. Our secondary aim was to assess other factors possibly related to cerebral ischemia and CI.

METHODS

Thirty-nine patients treated by chronic HD were included in this cross-sectional study. All measurements were performed before the initiation of an HD session. The Montreal Cognitive Assessment (MoCA) was administered according to published recommendations. Regional saturation of oxygen (rSO2) of the left frontal lobe was measured using the INVOS 5100C device. Basic medical history and laboratory data were recorded, and handgrip strength was analyzed. We used the unpaired t test to compare the rSO2 and other variables between cognitively normal patients (MoCA score ≥26) and those who displayed CI (MoCA score <26). Multiple linear regression analysis was used to adjust for principal confounders.

RESULTS

Cognitively impaired patients had lower brain rSO2 values compared to cognitively normal patients (48 ± 9 vs. 57 ± 10%, p = 0.01). Among other variables, higher red cell distribution width (15.8 ± 1.9 vs. 13.8 ± 1.6%, p = 0.01) and lower hand grip strength (49.2 ± 23.3 vs. 99.3 ± 31.4 lbs, p < 0.001) also displayed a significant association with CI. The relation between rSO2 and MoCA score was significant after adjustment for age and gender (p = 0.007).

CONCLUSION

Decreased brain oxygenation is associated with weaker cognitive performance in patients undergoing chronic HD. Further understanding the causes of cerebral ischemia in HD patients could lead to the prevention of cognitive decline in this population.