Red Blood Cell Distribution Width as a Risk Factor for 30/90-Day Mortality in Patients with Gastrointestinal Bleeding: Analysis of the MIMIC-IV Database

PURPOSE

The purpose of this research was to assess the relationship between red blood cell distribution width (RDW) and mortality in patients with gastrointestinal (GIB) bleeding in the intensive care unit (ICU).

METHODS

The information of the participants was obtained from the Medical Information Mart for Intensive Care IV database. The main outcome of this research was 30/90-day mortality, with ICU mortality and in-hospital mortality as secondary outcomes.

RESULTS

This research included 2924 patients with gastrointestinal bleeding in total. Patients with higher RDW had considerably higher 30/90-day and in-hospital mortality rates, as well as longer hospital stays and ICU stays. According to the Kaplan-Meier analysis, the 30/90-day mortality rate was remarkably higher among participants in the higher RDW group (P < 0.0001). In the adjusted multivariate Cox regression analysis, for 30-day mortality, the HR (95% CI) was 1.75 (1.37, 2.24) in comparison to Q1 in the reference group (P < 0.001). Analyses of 90-day mortality and in-hospital mortality both showed the same results. In the subgroup analysis, gender, myocardial infarction, chronic pulmonary disease, cerebrovascular disease and renal disease had no significant effect on the correlation between RDW values and mortality (all P > 0.05). The area under the ROC curve for RDW was 0.599 (95% CI 0.581-0.617) and 0.606 (95% CI 0.588-0.624) in 30/90-day ICU mortality.

CONCLUSION

The current research showed that RDW could be utilized as an independent indicator of short-term mortality in critically ill GIB patients at 30 and 90 days of hospital admission.

Decline in HbA1c during the first year of elexacaftor/tezacaftor/ivacaftor treatment in the Danish cystic fibrosis cohort: Short title: Decline in HbA1c after elexacaftor/tezacaftor/ivacaftor treatment

BACKGROUND

Elexacaftor/tezacaftor/ivacaftor (ETI) has improved the clinical status of individuals with cystic fibrosis (CF), however, whether ETI impacts glucose tolerance remains unknown. We aimed to study the change in glycated hemoglobin (HbA1c) and CF related diabetes (CFRD) status after initiation of ETI.

METHODS

We included individuals ≥12 years treated with ETI in Denmark in a longitudinal observational study. HbA1c was measured at baseline, 3, 6, 9 and 12 months after treatment initiation. Change in HbA1c was assessed in mixed models adjusted for age, sex, glucose tolerance and prior CFTR modulator treatment. In a sub-population with CFRD, we assessed the change in insulin usage, hypoglycemic events and the 30-day continuous glucose monitoring (CGM) parameters (i.e., average blood glucose, time below (≤3.9 mM) and above (>10.0 mM) normal range, and the variation in glucose) after 12 months of treatment.

RESULTS

Among 321 individuals with CF, HbA1c declined by 2.1 mmol/mol [95 % confidence interval (CI): -2.6; -1.5 mmol/mol] after 3 months and by 2.3 mmol/mol [95 %CI: -2.8; -1.9 mmol/mol] after 12 months of ETI treatment. The decline was independent of glucose tolerance status at baseline. In 26 individuals with CFRD at baseline, the mean decline in HbA1c was 3.6 mmol/mol [95 %CI: -6.9; -0.4 mmol/mol] after 12 months, but we did not observe any change in insulin usage, weekly number of hypoglycemic events or CGM parameters.

CONCLUSION

In the Danish CF cohort, HbA1c declined over 12 months of ETI treatment, however, among a subset with CFRD, we observed no change in insulin usage and CGM glucose levels.

Red cell distribution width and its polygenic score in relation to mortality and cardiometabolic outcomes

Introduction

Elevated red cell distribution width (RDW) has been associated with a range of health outcomes. This study aims to examine prognostic and etiological roles of RDW levels, both phenotypic and genetic predisposition, in predicting cardiovascular outcomes, diabetes, chronic kidney disease (CKD) and mortality.

Methods

We studied 27,141 middle-aged adults from the Malmö Diet and Cancer study (MDCS) with a mean follow up of 21 years. RDW was measured with a hematology analyzer on whole blood samples. Polygenic scores for RDW (PGS-RDW) were constructed for each participant using genetic data in MDCS and published summary statistics from genome-wide association study of RDW (n = 408,112). Cox proportional hazards regression was used to assess associations between RDW, PGS-RDW and cardiovascular outcomes, diabetes, CKD and mortality, respectively.

Results

PGS-RDW was significantly associated with RDW (Pearson's correlation coefficient = 0.133, p < 0.001). RDW was significantly associated with incidence of stroke (hazard ratio (HR) per 1 standard deviation = 1.06, 95% confidence interval (CI): 1.02-1.10, p = 0.003), atrial fibrillation (HR = 1.09, 95% CI: 1.06-1.12, p < 0.001), heart failure (HR = 1.13, 95% CI: 1.08-1.19, p < 0.001), venous thromboembolism (HR = 1.21, 95% CI: 1.15-1.28, p < 0.001), diabetes (HR = 0.87, 95% CI: 0.84-0.90, p < 0.001), CKD (HR = 1.08, 95% CI: 1.03-1.13, p = 0.004) and all-cause mortality (HR = 1.18, 95% CI: 1.16-1.20, p < 0.001). However, PGS-RDW was significantly associated with incidence of diabetes (HR = 0.96, 95% CI: 0.94-0.99, p = 0.01), but not with any other tested outcomes.

Discussion

RDW is associated with mortality and incidence of cardiovascular diseases, but a significant association between genetically determined RDW and incident cardiovascular diseases were not observed. However, both RDW and PGS-RDW were inversely associated with incidence of diabetes, suggesting a putative causal relationship. The relationship with incidence of diabetes needs to be further studied.

The relationship between red blood cell distribution width and islet β-cell function indexes in patients with latent autoimmune diabetes in adults

AIMS

The objective of this study is to explore the relationship between red blood cell distribution and islet β-cell function indexes in patients with Latent Autoimmune Diabetes in Adults.

METHODS

A total of 487 LADA patients were enrolled in this cross-sectional study. Patients were divided into three groups according to RDW tertiles. Clinical and laboratory measurements of age, height, weight, duration of diabetes, blood pressure, RDW, glycosylated hemoglobin A1c (HbA1c), C-peptide and blood lipids were performed. Homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of β-cell function (HOMA-β) were assessed using homeostasis model assessment (HOMA) based on fasting blood glucose (FBG) and fasting C-peptide index (FCP). Correlations and multiple linear regressions were implemented to determine the association of RDW and islet function indexes.

RESULTS

As the increase of serum RDW level, the presence of β-cell secretion increased(P < 0.05). Correlation analysis indicated that there were significant correlations between RDW and male sex, age, duration, TG, Cr, FCP, and HOMA-β in all subjects. Multiple linear regressions indicated that RDW was significantly correlated with HOMA-β in the total population in both unadjusted and adjusted analysis. This finding could be reproduced in the subgroup of low GAD titers for HOMA-β. RDW were significantly associated with HbA1c in LADA patients with high GAD titers, but the correlation was not found in subgroup with low GAD titers in either unadjusted analyses or adjusted analysis.

CONCLUSIONS

RDW is associated with β-cell function assessed by HOMA-β after adjusting for covariates in LADA patients with low GAD titers.

Age and Red Blood Cell Parameters Mainly Explain the Differences Between HbA1c and Glycemic Management Indicator Among Patients With Type 1 Diabetes Using Intermittent Continuous Glucose Monitoring

BACKGROUND

Glycated hemoglobin (HbA1c) is the gold standard to assess glycemic control in patients with diabetes. Glucose management indicator (GMI), a metric generated by continuous glucose monitoring (CGM), has been proposed as an alternative to HbA1c, but the two values may differ, complicating clinical decision-making. This study aimed to identify the factors that may explain the discrepancy between them.

METHODS

Subjects were patients with type 1 diabetes, with one or more HbA1c measurements after starting the use of the Freestyle Libre 2 intermittent CGM, who shared their data with the center on the Libreview platform. The 14-day glucometric reports were retrieved, with the end date coinciding with the date of each HbA1c measurement, and those with sensor use ≥70% were selected. Clinical data prior to the start of CGM use, glucometric data from each report, and other simultaneous laboratory measurements with HbA1c were collected.

RESULTS

A total of 646 HbA1c values and their corresponding glucometric reports were obtained from 339 patients. The absolute difference between HbA1c and GMI was <0.3% in only 38.7% of cases. Univariate analysis showed that the HbA1c-GMI value was associated with age, diabetes duration, estimated glomerular filtration rate, mean corpuscular volume (MCV), red cell distribution width (RDW), and time with glucose between 180 and 250 mg/dL. In a multilevel model, only age and RDW, positively, and MCV, negatively, were correlated to HbA1c-GMI.

CONCLUSION

The difference between HbA1c and GMI is clinically relevant in a high percentage of cases. Age and easily accessible hematological parameters (MCV and RDW) can help to interpret these differences.

Relationship between red cell distribution width/albumin ratio and carotid plaque in different glucose metabolic states in patients with coronary heart disease: a RCSCD-TCM study in China

BACKGROUND

Red cell distribution width/albumin ratio (RAR) is thought to be associated with the prognosis of a variety of diseases, including diabetes and heart failure. To date, no studies have focused on the relationship between RAR and carotid plaque in patients with coronary heart disease (CHD).

METHODS

A total of 10,267 patients with CHD were divided according to RAR quartiles (Q1: RAR ≤ 2.960; Q2: 2.960 < RAR ≤ 3.185; Q3: 3.185 < RAR < 3.441; Q4: RAR ≥ 3.441). Logistic regression was used to analyze the relationship between RAR and carotid plaques in CHD patients. The relationship between RAR and carotid plaques in according to sex, age and glucose regulation state groups were also assessed.

RESULTS

Among the 10,267 participants, 75.43% had carotid plaques. After adjusting for confounding factors, RAR was found to be associated with carotid plaque formation (OR: 1.23; 95% CI 1.08-1.39). The risk of carotid plaque formation in the Q4 group was 1.24 times higher than that in the Q1 group. After multivariate adjustment, RAR was associated with the risk of carotid plaque in female (OR: 1.29; 95% CI 1.09-1.52). And the relationship between RAR and carotid plaques in patients younger than 60 years old (OR: 1.43; 95% CI 1.16-1.75) was stronger than that in those older than 60 years old (OR: 1.29; 95% CI 1.10-1.51). Under different glucose metabolism states, RAR had the highest correlation with the risk of carotid plaques in diabetes patients (OR: 1.28; 95% CI 1.04-1.58).

CONCLUSIONS

RAR was significantly related to carotid plaques in patients with CHD. In addition, the correlation between RAR and the incidence of carotid plaque in patients with CHD was higher in women and middle-aged and elderly patients. In patients with CHD and diabetes, the correlation between RAR and carotid plaque was higher.

Relation of Red Cell Distribution Width to Glucose Metabolism and Adverse Long-Term Prognosis in Patients with Acute Coronary Syndrome

INTRODUCTION

Red cell distribution width (RDW) reflects the heterogeneity of red blood cell size. However, few studies examined whether RDW is related to glucose metabolism indices, such as fasting blood glucose (FBG) and hemoglobin A1c (HbA1c), diabetic mellitus (DM) state or long-term outcomes of acute coronary syndrome (ACS) patients.

METHODS AND RESULTS

A total of 448 consecutive patients with ACS were enrolled in this study. All patients were followed up for major cardiovascular adverse events (MACEs), and the mean follow-up was 952 days. Linear regression analysis showed that RDW inversely correlated with FBG but not HbA1c or DM. Kaplan-Meier survival curve analysis demonstrated that higher RDW levels were significantly positively associated with MACEs in the whole study population and the ACS patients with high FBG but not the low FBG group. Cox multivariate regression analysis revealed the independent function of RDW on MACEs in all ACS patients and ACS patients with high FBG. The receiver operating characteristic (ROC) curve demonstrated the optimal cutoff value of RDW for MACEs.

CONCLUSION

We first reported that higher RDW was associated with decreased FBG but not HbA1c or DM and an increased risk of MACEs in patients with ACS. This relationship was also found in ACS patients with higher FBG levels but not in ACS patients with lower FBG.

Identification of Putative Causal Relationships Between Type 2 Diabetes and Blood-Based Biomarkers in East Asians by Mendelian Randomization

Observational studies have revealed phenotypic associations between type 2 diabetes (T2D) and many biomarkers. However, causality between these conditions in East Asians is unclear. We leveraged genome-wide association study (GWAS) summary statistics on T2D (n = 77,418 cases; n = 356,122 controls) from the Asian Genetic Epidemiology Network (sample recruited during 2001-2011) and GWAS summary statistics on 42 biomarkers (n = 12,303-143,658) from BioBank Japan (sample recruited during 2003-2008) to investigate causal relationships between T2D and biomarkers. Applications of Mendelian randomization approaches consistently revealed genetically instrumented associations of T2D with increased serum potassium levels (liability-scale β = 0.04-0.10; P = 6.41 × 10-17-9.85 × 10-5) and decreased serum chloride levels (liability-scale β = -0.16 to -0.06; P = 5.22 × 10-27-3.14 × 10-5), whereas these 2 biomarkers showed no causal effects on T2D. Heritability Estimation Using Summary Statistics (ρ-HESS) and summary-data-based Mendelian randomization highlighted 27 genomic regions and 3 genes (α-1,3-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase (MGAT1), transducing-like enhancer (TLE) family member 1, transcriptional corepressor (TLE1), and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR)) that interactively associated with the shared genetics underlying T2D and the 2 biomarkers. Thus, T2D may causally affect serum potassium and chloride levels among East Asians. In contrast, the relationships of potassium and chloride with T2D are not causal, suggesting the importance of monitoring electrolyte disorders for T2D patients.

Sex-Specific Associations of Iron-Anemia Status With Hemoglobin A1C Levels Among Hispanics/Latinos Without Self-Reported Diabetes Mellitus: The Hispanic Community Health Study/Study of Latinos

OBJECTIVE

The objective of this study was to examine the sex-specific associations of mutually exclusive iron-anemia status categories with hemoglobin A1C (HbA1C) levels among U.S. Hispanics/Latinos without self-reported diabetes mellitus.

METHODS

Baseline cross-sectional data (7247 women and 4904 men without self-reported diabetes mellitus) from the Hispanic Community Health Study/Study of Latinos were analyzed. Per the American Diabetes Association's defined criteria, based on HbA1C levels, the participants were categorized as having normoglycemia, prediabetes, or probable diabetes mellitus. The iron-anemia status categories were as follows: no anemia and no iron deficiency (reference), iron deficiency, iron deficiency anemia (IDA), and non-iron deficiency anemia (non-IDA). Survey multinomial logistic regression models were used to examine the sex-specific associations of iron-anemia status with HbA1C levels after adjusting for sociodemographic, lifestyle, and clinical factors.

RESULTS

The age-standardized prevalence of iron-anemia status categories differed by sex. Compared with those with no anemia and no iron deficiency and normoglycemia, women with IDA had higher odds of having prediabetes (odds ratio [OR], 2.18; 95% CI, 1.64-2.89) and probable diabetes mellitus (OR, 3.59; 95% CI, 1.62-7.99) based on HbA1C levels; men with non-IDA had higher odds of having probable diabetes mellitus (OR, 2.97; 95% CI, 1.13-7.78) based on HbA1C levels. All other associations did not reach statistical significance.

CONCLUSION

Among U.S. Hispanics/Latinos without self-reported diabetes mellitus, the age-standardized prevalence of iron deficiency, IDA, and non-IDA is high and varies by sex. Women with IDA had higher odds of having prediabetes and probable diabetes mellitus, defined based on HbA1C levels. Men with non-IDA had higher odds of having probable diabetes mellitus, defined based on HbA1C levels. Iron-anemia status should be considered while interpreting elevated HbA1C levels among U.S. Hispanics/Latinos without self-reported diabetes mellitus.

The glycemic status determines the direction of the relationship between red cell distribution width and HbA1c

AIMS

Available studies conducted on heterogenous populations on the association between the erythrocyte distribution width (RDW) and HbA1c have reported a positive, negative or neutral relationship. The aim of the present study is to investigate the debated relationship between RDW and HbA1c among hematologically healthy individuals with and without type 2 diabetes mellitus (T2DM).

METHODS

Paired measurements of RDW and HbA1c of 183 hematologically healthy individuals (100 without DM, 83 with T2DM) were obtained. The association of HbA1c with a) hematologic parameters (hemoglobin, log[ferritin], RDW) and b) factors related to glycemia (BMI, fructosamine, FPG) was examined within each group separately and in the sum of the study sample.

RESULTS

There was a significant positive correlation of RDW with HbA1c among those without DM while the opposite was true among individuals with T2DM (r = 0.315, p = 0.001 and r = -0.275, p = 0.011). In the T2DM group a significant negative correlation with fructosamine was noted (r = -0.274, p = 0.012) which was absent among normoglycemic individuals. Among those without DM the association between HbA1c and RDW remained significant after adjustment for all tested parameters. In the population with T2DM the significance was attenuated after including glycemia-related factors values. In multivariable regression in the sum of the study sample, the interaction between diabetes status and RDW as regards HbA1c was significant [unstandardized correlation coefficient - 0.397 (-0.646 to -0.147), p = 0.002] and remained significant after adjustment for multiple potential confounders.

CONCLUSIONS

Among individuals without DM, the RDW likely reflects the non-glycemic interference on HbA1c values, while in T2DM RDW may serve as an indirect index of glycemia and dysmetabolism.

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

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

The relationship between red blood cell distribution and islet β-cell function indexes in patients with type 2 diabetes

BACKGROUND

Red cell distribution width (RDW) is a predicter of infections, cancer and diabetes. However, the relationship between RDW and β-cell function and insulin resistance remains unclear in patients with type 2 diabetes mellitus (T2DM). The aim of the study was to explore the relationship between RDW and β-cell function in patients with T2DM.

METHODS

A total of 559 T2DM patients were enrolled in this cross-sectional study. Patients were divided into three groups according to RDW tertiles. Clinical and biochemical characteristics such as age, duration of diabetes, blood pressure, RDW, glycosylated hemoglobin A1c (HbA1c), C-peptide and lipid profiles were collected. Homeostasis model assessment of insulin resistance (HOMA2IR) and homeostasis model assessment of β-cell function (HOMA2%B) were assessed using homeostasis model assessment (HOMA) based on fasting blood glucose (FBG) and fasting C-peptide index (FCPI). Correlations and multiple linear regressions were performed to explore the association between RDW and islet function indexes in total population and in different gender subgroups.

RESULTS

The HOMA2%B gradually increased according to RDW tertiles (lowest, second, highest RDW tertiles; 47.1(32.9-75.4), 54.05(34.1-81), and 57.9(38.65-95.4), respectively; P = 0.036). Correlation analysis indicated that there were significant correlations between RDW and age, diabetes duration, diastolic blood pressure (DBP), triglycerides (TG), aspartate transaminase (AST), FBG, HbA1c and HOMA2%B in all subjects. In male subjects, RDW correlated positively with age, high-density lipoprotein cholesterol (HDL) and AST, and it correlated negatively with body mass index (BMI), DBP and TG. In female subjects, RDW correlated positively with age, duration, serum creatinine (Cr), FCPI and HOMA2%B, and it correlated negatively with alanine transaminase (ALT), FBG and HbA1c. Multiple linear regressions indicated that RDW was significantly correlated with HOMA2%B and HbA1c in the total population in both unadjusted and adjusted analysis. This finding could be reproduced in the subgroup of men for HOMA2%B only and in women for HbA1c only.

CONCLUSIONS

RDW is associated with β-cell function assessed by HOMA2%B after adjusting for covariates in male T2DM patients.

A structural equation model to assess the pathways of body adiposity and inflammation status on dysmetabolic biomarkers via red cell distribution width and mean corpuscular volume: a cross-sectional study in overweight and obese subjects

Background

A study has been performed in overweight and obese subjects to assess the effects of adiposity and inflammation indicators on dysmetabolic biomarkers via red cell distribution width (RDW) and mean corpuscular volume (MCV), taking into account pro-antioxidant balance.

Methods

Data from 166 overweight subjects were analyzed by a path analysis model using structural equation modelling (SEM) to evaluate the direct and indirect pathway effects of adiposity, measured by body mass index (BMI) and waist circumference (WC), and inflammation status, measured by pro-antioxidant balance [reactive oxygen species (ROS)], lag-time and slope and C-reactive protein (CRP) values on dysmetabolic biomarkers, via RDW and MCV.

Results

BMI was strongly linked to CRP and ROS levels. Moreover, there was a significant negative decrease of MCV (1.546 femtoliters) linked to BMI indirectly via high CRP levels. Furthermore, WC affected RDW, indicating a possible mediatory role for RDW in relation to the relationship between WC and homeostatic model assessment (HOMA), insulin and high density lipoprotein (HDL), respectively. This was evident by the elevated HOMA and insulin levels and the decreased levels of HDL. Finally, ROS-related markers did not affect directly RDW and MCV.

Conclusion

The reported outcomes suggest that RDW might play a mediatory role in the relationship between WC and the dysmetabolic outcomes in overweight and obese individuals. CRP seems to modulate the linkage between BMI and MCV. This study provides the backbone structure for future scenarios and lays the foundation for further research on the role of RDW and MCV as suitable biomarkers for the assessment of cardiovascular disease (HDL-cholesterol), inflammatory bowels and insulin resistance.

The Effect of Red Cell Distribution Width Admission Value on the Outcome of Patients with First-ever ST-elevation Myocardial Infarction in Basrah

Background Red cell distribution width (RDW) reflects the volumetric heterogeneity of red blood cells (RBCs) and has proven to be a prognostic predictor for cardiovascular (CV) morbidity and mortality in ST-elevation myocardial infarction (STEMI). The study aims to evaluate the effect of the RDW admission value on the outcome of patients with STEMI. Materials and methods This is a cross-sectional observational study on (207) patients with first-ever STEMI, grouped according to their baseline RDW and thrombolysis eligibility into two groups. We calculated the in-hospital Global Registry of Acute Coronary Events (GRACE) score within 48 hours of presentation. Results The study demonstrated the impact of RDW on the primary STEMI outcomes (left ventricular ejection fraction (LVEF%), ST-resolution, arrhythmias, and cardiovascular mortality risk). It was nearly a gender-matched study, with a mean RDW of 14.20±1.86%. RDW>14% and age≥65 years were the strongest statistically significant independent predictors of STEMI outcome with LVEF % < 45%, ST-resolution, and CV mortality regardless of thrombolysis. The thrombolysis offers a logical significant negative relation with CV mortality. At the same time, hypertension, diabetes mellitus (DM), and smoking may cause an additional mortality burden, especially in elderly patients with high RDW who are not eligible for thrombolysis. There was a significant association between high GRACE to high RDW, with excellent specificity and sensitivity in predicting CV outcome. Conclusion The RDW is a simple to acquire index, with a good prognostic prediction of major adverse cardiovascular events (MACEs) and CV mortality in the STEMI patients. It is excellent in predicting STEMI outcomes, especially the response to thrombolysis.

The Relationship between Red Blood Cell Distribution Width and Incident Diabetes in Chinese Adults: A Cohort Study

BACKGROUND

Previous studies reported the controvertible association between red blood cell distribution width (RDW) and diabetes. The aim of this study is to explore whether RDW is associated with incident diabetes.

METHODS

We performed this cohort study in 16,971 Chinese adults (9,956 men and 7,015 women, aged 43.3 ± 12.8 years). The level of RDW was measured at baseline (2014). All the participants were further classified into four quartile groups based on baseline RDW. Fasting blood glucose (FBG) and glycated hemoglobin A1c (HbA1c) were measured annually during follow-up (2014-2019). Diabetes was diagnosed if either FBG ≥ 7.0 mmol/L or HbA1c ≥ 6.5%. We used the Cox proportional hazards regression model to evaluate the association between baseline RDW and incident diabetes.

RESULTS

We identified 2,703 new cases of diabetes during five-year follow-up. The incidence was 15.9%. Comparing with participants in the lowest quartile group (reference group), the adjusted hazard ratios (HR) for the risk of diabetes were 1.31 (95% CI: 1.16, 1.48) for the highest quartile group (p trend < 0.001), after adjustment for potential confounders. Further adjusting baseline FBG and HbA1c did not materially change the association between RDW and incident diabetes. Each unit increase of RDW was associated with a 16% higher risk of incident diabetes (HR = 1.16, 95% CI: 1.06, 1.26) in a fully adjusted model. Sensitivity analysis generated similar results with prospective analyses after excluding aged participants, participants who are overweight and with obesity, participants with elevated blood pressure, participants with decreased eGFR, and those with anemia at baseline.

CONCLUSIONS

High RDW was associated with high risk of developing diabetes in Chinese adults. As RDW is an inexpensive, noninvasive, and convenient indicator, RDW might be considered for inclusion in the risk assessment of high-risk groups of diabetes.

The predictive value of red cell distribution width on erectile dysfunction

Red cell distribution width (RDW), one of the biomarkers used to measure vascular ageing, is known to correspond with cardiovascular diseases. As coronary artery disease and erectile dysfunction (ED) are both caused by the same shared pathophysiology, in this study, we compared the RDW values of men diagnosed with ED and those of healthy controls. Ninety-nine patients who were diagnosed with ED were included in the study. The control group consists of 100 men who presented to our outpatient clinic. Patients' fasting blood glucose, triglyceride, total cholesterol and LDL cholesterol levels were significantly higher in men diagnosed with ED. While the mean RDW value was 13.49 ± 1.52 in men with ED, it was 12.91 ± 1.13 in the control group. When RDW values were compared between the two groups, the RDW values of men with ED were found to be statistically significantly higher. Multivariate analyses showed that only the patients' body mass index, fasting blood sugar, triglyceride (TG), low-density lipoprotein cholesterol, high-density lipoprotein cholesterol levels (HDL-C), TG/HDL-C ratio and RDW levels' relationship with ED was statistically significant. Although some studies have shown that RDW may be related to some diseases such as cardiovascular diseases and cancer, this appears to be the first study demonstrating a relationship between RDW and ED. RDW can be utilised as a predictor for the determination of the presence and monitoring of the severity of ED.

RED CELL DISTRIBUTION WIDTH AND ACUTE COMPLICATIONS OF DIABETES

CONTEXT

Red cell distribution width (RDW) has been associated with type 2 diabetes (T2DM), however data in relation to diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar non-ketotic acidosis (HONK) remains unclear.

OBJECTIVE

The aim of this study was to evaluate the association between RDW, MCV, and RDW/MVC values and acute complications in T2DM.

PATIENTS AND METHODS

RDW was measured in 90 T2DM patients (30 DKA, 30 HONK and 30 T2DM without acute complications). Clinical variables were analyzed by One -Way ANOVA, Kruskal-Wallis and Pearson analysis with SPSS software. Diagnostic screening tests and ROC curve analysis determined the cut-off point of MCV,RDW and RDW/MCV values.

RESULTS

DKA patients had higher levels of plasma glucose (524.20±201.43mg/dL, p<0.001), HbA1c (10.73±2.29%, p<0.001), osmotic pressure (310.32 mosm/L, p<0.001), RDW (14.61±1.75g/L, p<0.01), and the RDW/MCV ratio (0.17±0.04%, p<0.01), compared to HONK patients. RDW/MCV cut-off value was 0.15 with 90% sensitivity 50% specifity these values for only MCV were 76.67%-70%, for only RDW were 76.67%-63.33% respectively. The area under curve values for the ability to reflect DKA for RDW and the RDW/MCV ratio were 0.708 and 0.766, respectively (p<0.001).

CONCLUSIONS

RDW and RDW/MCV ratio were found associated with DKA and valuable in predicting DKA. However these parameters were not valuable in predicting HONK.

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

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

Red blood cell distribution width and the risk of being in poor glycemic control among patients with established type 2 diabetes

Background

The red cell distribution width (RDW) has been shown to be associated with the incidence and complications of type 2 diabetes (T2D). However, the relevance of RDW with the risk of being in poor glycemic control among patients with established T2D is largely overlooked.

Methods

A total of 702 T2D participants from the REACTION study were enrolled in this study. Blood routine index, fasting plasma glucose, hemoglobin A1c and lipid profile data were available for all of the enrolled population.

Results

The univariate logistic analysis revealed a significant association between RDW and the risk of being in poor glycemic control among T2D subjects with an odds ratio (OR) and a 95% confidence interval (CI) of 0.5 and 0.3–0.8, respectively, for the fourth vs the first quartile of RDW. The association strengthened after multivariable adjustment (OR [95% CI]: 0.3 [0.2–0.7]). Interaction and stratified analyses indicated that this association was seen only among T2D subjects with lower body mass index and/or serum lipid levels.

Conclusion

T2D patients with higher RDW had significantly lower risk of being in poor glycemic control. RDW may contribute to risk assessment for T2D individuals at risk of being in poor glycemic control.

No relationship between red blood cell distribution width and microcirculatory alterations in septic patients

BACKGROUND

Increased red cell distribution width (RDW), a quantitative measure of erythrocyte size variability, has been associated with increased mortality in critically ill patients.

METHODS

In this post-hoc analysis of prospectively collected data, we studied 122 septic patients with and without shock who had undergone sublingual microcirculatory assessment using Sidestream Dark Field (SDF) videomicroscopy. Patient demographics, comorbidities, the Acute Physiology and Chronic Health Evaluation (APACHE) II score on admission and the Sequential Organ Failure Assessment (SOFA) score on the day of the microcirculatory assessment were collected. The RDW was retrospectively collected on the day of the microcirculatory evaluation from the routine daily blood count analysis.

RESULTS

Median patient age was 68[55-77] years, and median APACHE II and SOFA scores were 22[17-28] and 10[8-12], respectively; ICU mortality was 43%. On the day of the microcirculatory analysis, the median RDW was 13.8[12.8-15.5]% and was elevated (>13.4%) in 74 (61%) patients. There was no correlation between RDW and microcirculatory parameters (functional capillary density, r2 = 0.12; proportion of small perfused vessels, r2 = 0.17; mean flow index, r2 = 0.14). RDW was not related to disease severity, the presence of shock or survival.

CONCLUSIONS

RDW is not associated with microcirculatory alterations or prognosis in septic patients.

Red cell distribution width is associated with hemoglobin A1C elevation, but not glucose elevation

AIMS

To investigate the association between red cell distribution width (RDW) and elevation of glucose/glycated hemoglobin (HbA1c).

METHODS

An analysis was conducted using data from a prospective cohort study of adults. People without prediabetes or diabetes (n=7,795) were followed for a mean of 2.90years (range: 1-7years, 95% confidence interval: 2.86-2.94years). Glucose elevation is defined as fasting glucose levels exceeding 5.6mmol/l, or 2-hour glucose values in the oral glucose tolerance test exceeding 7.8mmol/l. HbA1c elevation is defined as a HbA1c value exceeding a normal limit of 39mmol/mol (5.7%). Adjusted Cox proportional hazards regression models were used to assess the association between RDW quartiles and elevation of HbA1c/glucose.

RESULTS

The multiple-adjusted hazard ratios (95% confidence interval) of HbA1c elevation for increased quartiles of RDW were 1.00 (reference), 1.08 (0.89, 1.30), 1.28 (1.07, 1.54), and 1.54 (1.29, 1.85) (P for trend<0.0001). However, no significant association was observed between RDW and blood glucose (fasting and postprandial).

CONCLUSIONS

Elevated RDW is independently related to future HbA1c elevation, but not to glucose elevation. This suggests that RDW may associate with HbA1c through a non-glycemic way, which should be taken into consideration when using HbA1c as a diagnostic criterion of prediabetes or diabetes.

Red blood cell distribution width as a predictor of survival in nasal-type, extranodal natural killer/T-cell lymphoma

We retrospectively enrolled 191 nasal-type, extranodal natural killer/T-cell lymphoma (ENKTL) patients newly diagnosed from 2008 to 2016 at the Sichuan Cancer Hospital, in order to evaluate the relationship between disease outcomes, demographic and clinical factors, and red blood cell distribution width (RDW). C-index, fisher's exact test, univariate analysis, and cox regression analysis were applied. The median age of patients was 44 years and 134 (70%) were men. The cutoff of RDW was 46.2 fL determined by Cutoff Finder. Patients with RDW≤46.2 fL had significantly better progression-free survival (PFS) (3-year PFS, 80.4% vs. 63.1%; P=0.01) and overall survival (OS) (3-year OS, 83.2% vs. 65.5%; P=0.004) than those with RDW>46.2 fL. Multivariate analysis demonstrated that elevated RDW is an independent adverse predictor of OS (P=0.021, HR=2.04). RDW is an independent predictor of survival outcomes in ENKTL, which we found to be superior to both the prognostic index of natural killer lymphoma (PINK) and the Korean Prognostic Index (KPI) in discriminating patients with different outcomes in low-risk and high-risk groups (all P < 0.05). The new models combining RDW with the International Prognostic Index (IPI), KPI, and PINK showed more powerful prognostic value than corresponding original models. RDW represents an easily available and inexpensive marker for risk stratification in patients with ENKTL treated with radiotherapy-based treatment. Further prospective studies are warranted to confirm the prognostic value of RDW in ENKTL.

Red cell distribution width is correlated with extensive coronary artery disease in patients with diabetes mellitus

Introduction:

Previous studies have predicted an independent relationship between red cell distribution width (RDW) and the risk of death and cardiovascular events in patients with coronary artery disease (CAD). The aim of this study was to investigate the relationship between RDW and extensiveness of CAD in patients with diabetes mellitus (DM).

Methods:

Two hundred and thirty-three diabetic patients who underwent coronary angiographies at our centre in 2010 were included in the study. All of the angiograms were re-evaluated and Gensini scores were calculated. Triple-vessel disease wasdiagnosed in the presence of stenosis > 50% in all three coronary artery systems.

Result:

RDW was significantly higher in diabetic CAD patients (p < 0.001). Patients with CAD who had a RDW value above the cut-off point also had higher Gensini scores, higher percentages of obstructive CAD and triple-vessel disease (p ≤ 0.001 for all). According to the cut-off values calculated using ROC analysis, RDW > 13.25% had a high diagnostic accuracy for predicting CAD. RDW was also positively correlated with Gensini score, obstructive CAD and triple-vessel disease (r < 0.468 and p < 0.001 for all).

Conclusion:

RDW values were found to be increased in the diabetic CAD population. Higher RDW values were related to more extensive and complex coronary lesions in patients with DM.

Baseline red blood cell distribution width predicts long-term glycemic remission in patients with type 2 diabetes

AIMS

We explored whether red blood cell distribution width (RDW), a routinely checked item of complete blood cell counts, was an indicator of long-term euglycemia remission in patients with type 2 diabetes after short-term continuous subcutaneous insulin infusion (CSII).

METHODS

We analyzed the original data of patients enrolled in three randomized control trials from 2002 to 2014. CSII was administered to drug-naїve patients with newly diagnosed type 2 diabetes to achieve and maintain euglycemia for 2weeks.

RESULTS

A total of 185 patients were involved and 98 patients (52.97%) who achieved and maintained euglycemia for at least 12months were classified as the remission group, and the others as the non-remission group. Patients in remission group had a relatively lower value for baseline RDW (38.82±2.76vs 39.89±2.78fL, p=0.017) compared with those in non-remission group. A graded decrease of remission rate (67.50%, 55.00%, 53.66% and 30.77% for Quartile 1 to Quartile 4 respectively, P<0.05) was observed with the increasing of RDWs. The risk of hyperglycemic relapse was significantly increased for those in the highest quartile compared with the lowest (hazard ratio=2.68; 95% CI, 1.38-5.22). Those who achieved euglycemia within 7days or obtained a better fasting glucose after therapy had preferable remission rates.

CONCLUSIONS

Patients with lower baseline RDWs are more likely to maintain a one-year euglycemia remission after short-term CSII. A faster normalization of glucose during treatment and a lower fasting glucose after therapy are correlated with a long-term glucose control.

Prognostic Value of Red Blood Cell Distribution Width in Non-Cardiovascular Critically or Acutely Patients: A Systematic Review

BACKGROUND

RDW (red cell distribution width) has been reported to been associated with the prognosis of patients with cardiovascular diseases. However, RDW is often overlooked by clinicians in treating patients with non-cardiovascular diseases, especially in an emergency. The objective of this systematic review is to explore the prognostic value of RDW in non-cardiovascular emergencies.

METHODS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically searched from their inception to December 31, 2015. We included studies examining the relationship between RDW and mortality rate by adjusting important covariables in non-cardiovascular emergencies. All included studies were divided into three groups. Group A: general critically ill patients; Group B: patients with infectious disease; Group C: other conditions. We extracted each study' characteristics, outcomes, covariables, and other items independently.

RESULTS

A total of 32 studies were eligible for inclusion in our meta-analysis. Six studies belonged to Group A, 9 studies belonged to Group B and 17 studies belonged to Group C. Among these included studies, RDW was assessed as a continuous variable (per 1% increase) in 16 studies, as a binary variable in 8 studies, and as a categorical variable in 8 studies. In addition, AUCs (area under the receiver operating characteristic curve) of RDW for predicting mortality were reported in 25 studies. All studies were published between 2011-2015. The qualities of included 32 studies were moderate or high.

CONCLUSION

The present systematic review indicates that the increased RDW is significantly associated with a higher mortality rate in an non-cardiovascular emergency. The low cost and readily accessible of this laboratory variable may strengthen its usefulness in daily practice in the future.

Prognostic Value of Red Blood Cell Distribution Width in Non-Cardiovascular Critically or Acutely Patients: A Systematic Review

Background

RDW (red cell distribution width) has been reported to been associated with the prognosis of patients with cardiovascular diseases. However, RDW is often overlooked by clinicians in treating patients with non-cardiovascular diseases, especially in an emergency. The objective of this systematic review is to explore the prognostic value of RDW in non-cardiovascular emergencies.

Methods

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically searched from their inception to December 31, 2015. We included studies examining the relationship between RDW and mortality rate by adjusting important covariables in non-cardiovascular emergencies. All included studies were divided into three groups. Group A: general critically ill patients; Group B: patients with infectious disease; Group C: other conditions. We extracted each study’ characteristics, outcomes, covariables, and other items independently.

Results

A total of 32 studies were eligible for inclusion in our meta-analysis. Six studies belonged to Group A, 9 studies belonged to Group B and 17 studies belonged to Group C. Among these included studies, RDW was assessed as a continuous variable (per 1% increase) in 16 studies, as a binary variable in 8 studies, and as a categorical variable in 8 studies. In addition, AUCs (area under the receiver operating characteristic curve) of RDW for predicting mortality were reported in 25 studies. All studies were published between 2011–2015. The qualities of included 32 studies were moderate or high.

Conclusion

The present systematic review indicates that the increased RDW is significantly associated with a higher mortality rate in an non-cardiovascular emergency. The low cost and readily accessible of this laboratory variable may strengthen its usefulness in daily practice in the future.

Differences in Red Blood Cell Indices Do Not Explain Racial Disparity in Hemoglobin A1c in Children with Type 1 Diabetes

We assessed the association of erythrocyte indices on mean blood glucose-independent racial disparity in hemoglobin A1c (HbA1c) in youth with type 1 diabetes. Blacks still had higher HbA1c after adjustment for mean blood glucose, red blood cell indices, age, and sex. Such differences need to be taken into account when interpreting HbA1c in Black patients.

Differences in Hemoglobin A1c Between Hispanics/Latinos and Non-Hispanic Whites: An Analysis of the Hispanic Community Health Study/Study of Latinos and the 2007-2012 National Health and Nutrition Examination Survey

OBJECTIVE

To determine whether, after adjustment for glycemia and other selected covariates, hemoglobin A1c (HbA1c) differed among adults from six Hispanic/Latino heritage groups (Central American, Cuban, Dominican, Mexican, Puerto Rican, and South American) and between Hispanic/Latino and non-Hispanic white adults without self-reported diabetes.

RESEARCH DESIGN AND METHODS

We performed a cross-sectional analysis of data from 13,083 individuals without self-reported diabetes from six Hispanic/Latino heritage groups, enrolled from 2008 to 2011 in the Hispanic Community Health Study/Study of Latinos, and 2,242 non-Hispanic white adults enrolled during the 2007-2012 cycles of the National Health and Nutrition Examination Survey. We compared HbA1c levels among Hispanics/Latinos and between Hispanics/Latinos and non-Hispanic whites before and after adjustment for age, sex, fasting (FPG) and 2-h post-oral glucose tolerance test (2hPG) glucose, anthropometric measurements, and selected biochemical and hematologic variables and after stratification by diabetes status: unrecognized diabetes (FPG ≥7.1 mmol/L or 2hPG ≥11.2 mmol/L), prediabetes (FPG 5.6-7.0 mmol/L or 2hPG 7.8-11.1 mmol/L), and normal glucose tolerance (FPG <5.6 mmol/L and 2hPG <7.8 mmol/L).

RESULTS

Adjusted mean HbA1c differed significantly across all seven groups (P < 0.001). Non-Hispanic whites had significantly lower HbA1c (P < 0.05) than each individual Hispanic/Latino heritage group. Upon stratification by diabetes status, statistically significant differences (P < 0.001) in adjusted mean HbA1c persisted across all seven groups.

CONCLUSIONS

HbA1c differs among Hispanics/Latinos of diverse heritage groups and between non-Hispanic whites and Hispanics/Latinos after adjustment for glycemia and other covariates. The clinical significance of these differences is unknown.

Association of the Elevated Red Blood Cell Distribution Width with the Risk of Developing Diabetes Mellitus

Objective The aim of this study was to determine whether elevated levels of RDW-coefficient of variation (CV) are associated with the development of diabetes mellitus (DM) in a population of healthy middle- and old-aged individuals. Method We conducted a retrospective cohort study. A total of 2,688 individuals (aged 49-66 years) without a DM diagnosis, impaired fasting glucose, or anemia at baseline were grouped according to the RDW-CV quartile, and the onset of DM during a 4-year period was recorded for each group. Results The correlation coefficients for the RDW-CV and waist circumference and for the RDW-CV and HbA1c were 0.114 and 0.133, respectively. The relative risks of future DM in RDW-CV quartiles II, III, and IV (high) compared with RDW-CV quartile I (low) were 1.9 [95% confidence interval (CI) 1.0-3.6, p=0.057], 1.6 (95% CI 0.8-3.0, p=0.157), and 2.2 (95% CI 1.2-4.0, p=0.015), respectively. After adjusting for sex, age, waist circumference, hemoglobin A1c, triglycerides, high density lipoprotein-cholesterol (HDL-C), and high-sensitivity C-reactive protein, the multivariate relative risk for the highest vs. the lowest RDW-CV quartile was 1.8 (95% CI, 1.1-3.4, p=0.046). Conclusion These data indicate that an elevated RDW-CV is associated with an increased incidence of DM.

The Prognostic Role of Red Blood Cell Distribution Width in Coronary Artery Disease: A Review of the Pathophysiology

Red blood cell distribution width (RDW) is a measure of red blood cell volume variations (anisocytosis) and is reported as part of a standard complete blood count. In recent years, numerous studies have noted the importance of RDW as a predictor of poor clinical outcomes in the settings of various diseases, including coronary artery disease (CAD). In this paper, we discuss the prognostic value of RDW in CAD and describe the pathophysiological connection between RDW and acute coronary syndrome. In our opinion, the negative prognostic effects of elevated RDW levels may be attributed to the adverse effects of independent risk factors such as inflammation, oxidative stress, and vitamin D₃ and iron deficiency on bone marrow function (erythropoiesis). Elevated RDW values may reflect the intensity of these phenomena and their unfavorable impacts on bone marrow erythropoiesis. Furthermore, decreased red blood cell deformability among patients with higher RDW values impairs blood flow through the microcirculation, resulting in the diminution of oxygen supply at the tissue level, particularly among patients suffering from myocardial infarction treated with urgent revascularization.

Association between Inflammation and Biological Variation in Hemoglobin A1c in U.S. Nondiabetic Adults

CONTEXT

Inflammation is associated with higher glycated hemoglobin (HbA1c) levels. Whether the relationship is independent of blood glucose concentration remains unclear.

OBJECTIVE

The hemoglobin glycation index (HGI) was used to test the hypothesis that interindividual variation in HbA1c is associated with inflammation.

PARTICIPANTS

This study used nondiabetic adults from the National Health and Nutrition Examination Survey (1999-2008).

MAIN OUTCOME MEASURES

A subsample of participants was used to estimate the linear regression relationship between HbA1c and fasting plasma glucose (FPG). Predicted HbA1c were calculated for 7323 nondiabetic participants by inserting FPG into the equation, HbA1c = 0.017 × FPG (mg/dL) + 3.7. HGI was calculated as the difference between the observed and predicted HbA1c and the population was divided into low, moderate, and high HGI subgroups. Polymorphonuclear leukocytes (PMNL), monocytes, and C-reactive protein (CRP) were used as biomarkers of inflammation.

RESULTS

Mean HbA1c, CRP, monocyte, and PMNL levels, but not FPG, progressively increased in the low, moderate, and high HGI subgroups. There were disproportionately more Blacks than whites in the high HGI subgroup. CRP (ß, 0.009; 95% confidence interval [CI], 0.0001-0.017), PMNL (ß, 0.036; 95% CI, 0.010-0.062), and monocyte count (ß, 0.072; 95% CI, 0.041-0.104) were each independent predictors of HGI after adjustment for age, sex, race, triglycerides, hemoglobin level, mean corpuscular volume, red cell distribution width, and obesity status.

CONCLUSIONS

HGI reflects the effects of inflammation on HbA1c in a nondiabetic population of U.S. adults and may be a marker of risk associated with inflammation independent of FPG, race, and obesity.

Modulation of red blood cell population dynamics is a fundamental homeostatic response to disease

Increased red blood cell (RBC) volume variation (RDW) has recently been shown to predict a wide range of mortality and morbidity: death due to cardiovascular disease, cancer, infection, renal disease, and more; complications in heart failure and coronary artery disease, advanced stage and worse prognosis in many cancers, poor outcomes in autoimmune disease, and many more. The mechanisms by which all of these diseases lead to increased RDW are unknown. Here we use a semi-mechanistic mathematical model of in vivo RBC population dynamics to dissect the factors controlling RDW and show that elevated RDW results largely from a slight reduction in the in vivo rate of RBC turnover. RBCs become smaller as they age, and a slight reduction in the rate of RBC turnover allows smaller cells to continue circulating, expanding the low-volume tail of the RBC population's volume distribution, and thereby increasing RDW. Our results show that mildly extended RBC lifespan is a previously unrecognized homeostatic adaptation common to a very wide range of pathologic states, likely compensating for subtle reductions in erythropoietic output. A mathematical model-based estimate of the clearance rate may provide a novel early-warning biomarker for a wide range of morbidity and mortality.

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

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

Red blood cell distribution width in patients with cryptogenic stroke

BACKGROUND

There is no information about a possible association of red blood cell distribution width (RDW) with cryptogenic stroke (CS). We aimed to analyze the association of RDW with CS.

PATIENTS AND METHODS

One hundred and sixty-three patients with CS were included along with 186 healthy controls. Fibrinogen, leukocytes, hemoglobin, and erythrocyte indices were evaluated.

RESULTS

Patients showed higher RDW, leukocyte count, and body mass index (BMI) than controls (P < .05). No differences were observed in the erythrocyte indices or in glucose, cholesterol, and triglycerides levels (P > .05). When patients with anemia were excluded from the study (6 controls and 5 cases), the differences between cases and controls persisted (P = .005). Multivariate logistic regression revealed that, after adjusting for potential confounders (anemia, age > 40 years, gender, and fibrinogen >382 mg/dL, total cholesterol >240 mg/dL, and BMI > 28.7 kg/m(2)), RDW >14% was the only parameter that independently increased the risk of CS.

CONCLUSION

The RDW >14% increased the risk of CS by 2.5-fold, irrespectively of anemia, inflammation, and lipidic profile.

Red cell distribution width, haemoglobin A1c and incidence of diabetes mellitus

OBJECTIVE

Hyperglycaemia has multiple effects on the red blood cell (RBC), including glycation of haemoglobin, reduced deformability and reduced lifespan. Red cell distribution width (RDW) is a measure of the heterogeneity of erythrocyte volumes. The aim of this study was to explore the relationships between RDW and glucose, haemoglobin A1c (HbA1c) and incidence of diabetes mellitus (DM).

DESIGN, SETTING AND SUBJECTS

RDW and mean corpuscular volume were measured in 26 709 non-diabetic participants (aged 45-73 years) from the population-based Malmö Diet and Cancer cohort. HbA1c and fasting venous blood glucose levels were measured in 4845 subjects.

MAIN OUTCOME MEASURE

Incidence of DM (n = 2944) over 14 years of follow-up was studied by linkage with national and local DM registers.

RESULTS

Individuals with low RDW had significantly higher risk of developing DM [adjusted hazard ratio (HR) 1.48, 95% confidence interval (CI) 1.29-1.70, for 1st vs. 4th quartile], especially in subjects with impaired fasting glucose (n = 416) (HR 2.15, 95% CI 1.12-4.14). Low RDW was also associated with significantly higher waist circumference and glucose, insulin and triglyceride concentrations. By contrast, RDW was significantly and positively associated with HbA1c, corresponding an increase in HbA1c of 0.10% per 1 SD increase in RDW.

CONCLUSION

Low RDW is associated with increased incidence of DM independently of other risk factors. We propose that low RDW could be a surrogate marker of reduced RBC survival, with lower HbA1c due to shorter duration of glucose exposure. RDW is a biomarker that could improve risk assessment for individuals at risk of developing DM.

Red Blood Cell Distribution Width Level: A Predictive Marker for Early Detection and Monitoring of Diabetic Nephropathy Progression

Chronic inflammation may be one of the factors that contribute to the development of diabetic nephropathy (DN). However, erythropoiesis, erythrocyte circulatory half-life and erythrocyte deformability may be influenced by inflammation. Thus, red blood cell distribution width (RDW) levels increase in inflammatory conditions. We investigated the RDW values and related factors in patients with uncomplicated type 2 diabetes mellitus (DM) and diabetic patients with DN. We carried out a retrospective study on patients with type 2 DM admitted to our hospital. Subjects were divided into three groups. Group 1 consisted of healthy subjects. Group 2 consisted of patients with uncomplicated type 2 DM. Patients with various stages of DN were included in Group 3. The RDW values in group 1 subjects were significantly lower than those in group 2 and 3 patients (p<0.05). The RDW values of group 3 patients were higher than those in the other two groups (p<0.05). While the RDW values had positive correlation with blood pressure, serum creatinine, HbA1c, body mass index, proteinuria, platelet (PLT), triglyceride, low density lipoprotein (LDL), total cholesterol (TC), and fasting blood glucose (r values: 0.95, 0.72, 0.56, 0.86, 0.82, 0.76, 0.88, 0.84, 0.88, 0.86, respectively) (p<0.05 for all), there was negative correlation between estimated glomerular filtration rate (eGFR), albumin, high density lipoprotein (HDL) and RDW levels (r values: −0.92, −0. 88, −0.78, respectively) (p value < 0.05 for all).

An increase in red blood cell distribution width from baseline predicts mortality in patients with severe sepsis or septic shock

Introduction

A potential independent association was recently demonstrated between high red blood cell distribution width (RDW) and the risk of all-cause mortality in critically ill patients, although the mechanism underlying this relationship remains unclear. Little is known about the impact changes in RDW may have on survival in critically ill patients. Therefore, we investigated the prognostic significance of changes in RDW during hospital stay in patients with severe sepsis or septic shock.

Methods

We prospectively enrolled 329 patients who were admitted to the emergency department (ED) and received a standardized resuscitation algorithm (early-goal directed therapy) for severe sepsis or septic shock. The relationship between the changes in RDW during the first 72 hours after ED admission and all-cause mortality (28-day and 90-day) were analyzed by categorizing the patients into four groups according to baseline RDW value and ΔRDW_72hr-adm (RDW at 72 hours – RDW at baseline).

Results

The 28-day and 90-day mortality rates were 10% and 14.6%, respectively. Patients with increased RDW at baseline and ΔRDW_72hr-adm >0.2% exhibited the highest risks of 28-day and 90-day mortality, whereas the patients with normal RDW level at baseline and ΔRDW_72hr-adm ≤0.2% (the reference group) had the lowest mortality risks. For 90-day mortality, a significantly higher mortality risk was observed in the patients whose RDW increased within 72 hours of ED admission (normal RDW at baseline and ΔRDW_72hr-adm >0.2%), compared to the reference group. These associations remained unaltered even after adjusting for age, sex, Sequential Organ Failure Assessment (SOFA) score, Charlson Comorbidity Index, renal replacement therapy, albumin, hemoglobin, lactate, C-reactive protein and infection sites in multivariable models.

Conclusions

We found that an increase in RDW from baseline during the first 72 hours after hospitalization is significantly associated with adverse clinical outcomes. Therefore, a combination of baseline RDW value and an increase in RDW can be a promising independent prognostic marker in patients with severe sepsis or septic shock.

Altered red blood cell distribution width in overweight adolescents and its association with markers of inflammation

BACKGROUND

Obesity and the metabolic syndrome are dramatically increasing problems. Red blood cell distribution width (RDW), the variability in size of circulating red blood cells, has been demonstrated to be altered in different clinical settings. This analysis aimed to investigate the relationship between RDW and obesity in adolescents and in an animal model of diet-induced obesity (DIO).

METHODS

Seventy-nine male adolescents (aged 13-17 years) were studied. Thirty-seven of them were overweight (body mass index ≥ 90th percentile). RDW, markers of inflammation and stem cell factor (SCF) were determined. In an animal study, mice were fed with different diets for 15 weeks. RDW was determined using an animal blood count machine.

RESULTS

RDW differed significantly between normal-weight adolescents (13.07 ± 0.09) and overweight adolescents (13.39 ± 0.10, P = 0.015), whereas erythrocyte counts and haematocrit did not differ. RDW correlated to markers of inflammation and inversely to SCF. In the mice animal model, nutritional changes increased RDW, whereas overweight per se did not change RDW.

CONCLUSIONS

RDW is elevated in overweight and reflects the inflammatory state. RDW potentially represents an additional and cost-effective tool to indicate inflammation. Future studies are needed to understand the differential influences of nutrition and overweight on RDW.