Red cell distribution width and risk of cardiovascular mortality: Insights from National Health and Nutrition Examination Survey (NHANES)-III

Exploring the hemoglobin-to-red blood cell distribution width ratio (HRR) to peripheral arterial disease nexus: a comprehensive analysis of NHANES data from 1999 to 2004

Objective

This study aimed to investigate the correlation between the Hemoglobin-to-Red Blood Cell Distribution Width Ratio (HRR) and Peripheral Artery Disease (PAD) prevalence, utilizing data from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2004.

Methods

The study employed a cross-sectional design, analyzing data from 5,196 participants aged 40 and above. PAD was diagnosed using the Ankle-Brachial Index (ABI), with ABI less than 0.9 indicating PAD. HRR, calculated as the ratio of hemoglobin (HB) to red blood cell distribution width (RDW), was stratified into quartiles. Covariates included demographic and clinical variables such as BMI, lipid profiles, and diabetes status. Logistic regression analysis was conducted to assess the relationship between HRR and PAD, adjusting for potential confounders.

Results

The study found that higher HRR quartiles were associated with a decreased risk of PAD. After adjusting for confounders, the odds ratios for PAD in relation to the second, third, and fourth quartiles of HRR compared to the first quartile were 0.71, 0.62, and 0.44, respectively (P < 0.001). A one-unit increase in HRR corresponded to a 56% reduction in the probability of PAD. ROC analysis indicated HRR as a stronger protective factor for PAD compared to other variables. Stratified analyses revealed that younger age and lower BMI amplified the protective effect of HRR on PAD.

Conclusion

The study demonstrated a significant inverse relationship between HRR and PAD, suggesting that HRR may serve as a protective factor against PAD. This finding highlights the potential role of HRR in the pathogenesis of PAD and its clinical implications.

A Meta-analysis of the Utility of Red Cell Distribution Width as a Biomarker to Predict Outcomes in Pediatric Illness (PROSPERO CRD42020208777)

Red cell distribution width (RDW) is an average of the variation in red blood cell (RBC) sizes reported on a complete blood count. An elevated RDW indicates a pathological process that is affecting erythropoiesis. Studies showed that as the severity of disease process increases, the RDW often increases as well. Particularly in resource-limited countries, RDW has been studied as an outcome predictor for conditions in a variety of disciplines and is offered as an adjunct monitoring tool that is cost effective, readily available, and indicative of pathological processes amenable to intervention. Particularly in pediatric critical care settings, RDW has been shown to be a reliable tool for surveillance of disease states such as sepsis. Despite the increased attention of RDW as a marker for disease outcome, collective evaluation on the utility of RDW as a marker for outcome in pediatric critical care settings is lacking. We offer a systematic review and meta-analysis of published studies to assess the ability of RDW to predict illness severity and mortality among pediatric critical care patients. Among eight studies of over 4,800 patients, we found over a two-fold increase in odds for mortality in critically ill children whose RDW was above 15.7%. This is the first systematic review of RDW being used to predict mortality in critically ill children and findings of this study may prompt early intervention in the pediatric critical care setting.

Nonlinear relationship of red blood cell indices (MCH, MCHC, and MCV) with all-cause and cardiovascular mortality: A cohort study in U.S. adults

BACKGROUND

In recent years, increasing attention has been focused on the impact of red blood cell indices (RCIs) on disease prognosis. We aimed to investigate the association of mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular volume (MCV) with mortality.

METHODS

The study used cohort data from U.S. adults who participated in the 1999-2008 National Health and Nutrition Examination Survey. All-cause mortality was the primary outcome during follow-up, with secondary cardiovascular mortality outcomes. COX regression was applied to analyze the connection between RCIs and mortality. We adopted three models to minimize potential bias. Smooth-fit curves and threshold effect analyses were utilized to observe the dose-response relationship between RCIs and all-cause and cardiovascular mortality. In addition, we performed sensitivity analyses.

RESULTS

21,203 individuals were enrolled in our research. During an average 166.2 ± 54.4 months follow-up, 24.4% of the population died. Curve fitting indicated a U-shaped relationship between MCV and MCH with all-cause mortality, and the relationship of MCHC to all-cause mortality is L-shaped. We identified inflection points in the relationship between MCV, MCH, and MCHC and all-cause mortality as 88.56732 fl, 30.22054 pg, 34.34624 g/dl (MCV <88.56732 fl, adjusted HR 0.99, 95 CI% 0.97-1.00; MCV >88.56732 fl, adjusted HR 1.05, 95 CI% 1.04-1.06. MCH <30.22054 pg, adjusted HR 0.95, 95 CI% 0.92-0.98; MCH >30.22054 pg, adjusted HR 1.08, 95 CI% 1.04-1.12. MCHC <34.34624 g/dl, adjusted HR 0.88, 95 CI% 0.83-0.93). Besides, the MCV curve was U-shaped in cardiovascular mortality (MCV <88.56732 fl, adjusted HR 0.97, 95 CI% 0.94-1.00; MCV >88.56732 fl, adjusted HR 1.04, 95 CI% 1.01-1.06).

CONCLUSION

This cohort study demonstrated that RCIs (MCH, MCHC, and MCV) were correlated with mortality in the general population. Three RCIs were nonlinearly correlated with all-cause mortality. In addition, there were nonlinear relationships between MCH and MCV and cardiovascular mortality.

Red Cell Distribution Width and Absolute Lymphocyte Count Associate With Biomarkers of Inflammation and Subsequent Mortality in Rheumatoid Arthritis

OBJECTIVE

Morbidity and mortality in rheumatoid arthritis (RA) is partly mitigated by maintaining immune and hematologic homeostasis. Identification of those at risk is challenging. Red cell distribution width (RDW) and absolute lymphocyte count (ALC) associate with cardiovascular disease (CVD) and mortality in the general population, and with disease activity in RA. How these variables relate to inflammation and mortality in RA was investigated.

METHODS

In a retrospective single Veterans Affairs (VA) Rheumatology Clinic cohort of 327 patients with RA treated with methotrexate (MTX)+/- a tumor necrosis factor (TNF) inhibitor (TNFi), we evaluated RDW and ALC before and during therapy and in relation to subsequent mortality. Findings were validated in a national VA cohort (n = 13,914). In a subset of patients and controls, we evaluated inflammatory markers.

RESULTS

In the local cohort, high RDW and low ALC prior to MTX treatment was associated with subsequent mortality over 10 years (both P < 0.001). The highest mortality was observed in those with both high RDW and low ALC. This remained after adjusting for age and comorbidities and was validated in the national RA cohort. In the immunology cohort, soluble and cellular inflammatory markers were higher in patients with RA than in controls. ALC correlated with age, plasma TNF receptor II, natural killer HLA-DR mean fluorescence intensity, and CD4CM/CD8CM HLA-DR/CD38%, whereas RDW associated with age and ALC. MTX initiation was followed by an increase in RDW and a decrease in ALC. TNFi therapy added to MTX resulted in an increase in ALC.

CONCLUSION

RDW and ALC before disease-modifying antirheumatic drug therapy are associated with biomarkers of monocyte/macrophage inflammation and subsequent mortality. The mechanistic linkage between TNF signaling and lymphopenia found here warrants further investigation.

Assessment of Red Cell Distribution Width among Sudanese Patients with Hypothyroidism.. [DOI: 10.21203/rs.3.rs-2518318/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: Thyroid dysfunction has a strong linkage with anemia. RDW was traditionally regarded as a part of routine evaluation of anemia Elevated RDW level was significantly associated with subclinical hypothyroidism and hypothyroidism. Objectives: The aim of this is study to assess the Red Cell Distribution Width (RDW-CV and RDW-SD) in patients with hypothyroidism. Methodology: This is a case-control laboratory-based study conducted among 50 patients with hypothyroidism as cases (38.50 ± 10.46 years; 36% males and 64% females) and 50 normal healthy individuals as controls (35.52 ± 11.64 years; 46% males and 54% females) in National Cancer Institute – University of Gezira (NCI-UG), Gezira State, Sudan from January to October 2020. Three ml of venous blood sample was collected in an EDTA container. Red cell parameters (RBC count, MCV, RDW-CV, and RDW-SD) were measured using Sysmex XP 300 Cell Counter. SPSS computer program (v 22.0) was used for data analysis. Results: The average RDW (SD and CV) of cases were higher than controls (P value = 0.000, 0.000 respectively). There was a significant difference in RDW-CV between mild and severe hypothyroidism (P value = 0.040). RDW-SD and RDW-CV had significant positive correlation within TSH (r = 0.361, P value = 0.000; r = 0.407, P value = 0.000 respectively) and significant negative correlation within T3 (r = - 0.419, P value = 0.000; r = - 0.507, P value = 0.000 respectively) and T4 (r = - 0.406, P value = 0.000; r = - 0.506, P value = 0.000 respectively). Conclusion: The study concluded that RDW was significantly higher in patients with hypothyroidism and had a significant positive correlation with TSH and a significant negative correlation within T3 and T4. So, RDW may be used as a significant clinical marker of hypothyroidism.

Subclinical Vitamin C Plasma Levels Associated with Increased Risk of CAD Diagnosis via Inflammation: Results from the NHANES 2003-2006 Surveys

Vitamin C remains an important, yet frequently unassessed, component of a healthy immune system though it may prove useful in alleviating the chronic inflammatory processes underlying chronic diseases such as coronary artery disease (CAD). Recent research identified a sizeable proportion of the United States population with insufficient vitamin C plasma levels and significant associations to both acute and chronic inflammation. This cross-sectional study used the 2003-2006 NHANES surveys data to extrapolate associations between plasma vitamin C levels (deficiency, hypovitaminosis, inadequate, adequate, and saturating) and CAD through inflammation (C-reactive protein and red cell distribution width). Increased reports of CAD diagnosis were identified in participants with vitamin C deficiency (OR: 2.31, CI: 1.49-3.58) and inadequate plasma levels (OR: 1.39, CI: 1.03-1.87). No significant correlation was identified between any other plasma vitamin C quintiles and CAD. When inflammation was controlled, previous associations in the deficient level of plasma vitamin C were no longer significant in association with CAD and participants with inadequate plasma vitamin C showed a reduced association to CAD diagnoses (OR: 0.33, CI: 0.13-0.86). Most chronic inflammation and vitamin C plasma statuses do not demonstrate specific signs or symptoms until the deficient level of vitamin C and/or disease. Thus, increased surveillance of both, and healthy nutritional habits remain crucial modifiable risk factors for disease prevention.

CORRELATION BETWEEN RED BLOOD CELL DISTRIBUTION WIDTH-TO-PLATELET RATIO AND MORTALITY IN PATIENTS WITH ACUTE RESPIRATORY DISTRESS SYNDROME: A RETROSPECTIVE COHORT STUDY

ABSTRACT

Background: This study aims to assess the prognostic value of red blood cell distribution width-to-platelet ratio (RPR) in acute respiratory distress syndrome (ARDS) patients. Methods: The data collected from 540 ARDS patients from 2001 to 2012 were obtained from the Medical Information Mart for Intensive Care III Database. The 28-day all-cause mortality risk was considered as the primary outcome parameter, and the secondary outcomes were 60- and 90-day all-cause mortality. The association between RPR (≥0.19 vs. <0.19) and mortality was assessed by Cox proportional hazards models, and potential nonlinear associations were assessed by restricted cubic spline regression analysis. Results: The 28-day all-cause mortality was 22.4%. Among the 121 deaths, 92 (20.0%) presented with an RPR <0.19, and 29 patients had RPR ≥0.19 ( P < 0.001). The 60- and 90-day all-cause mortality was 27% and 28.7%, respectively. After adjusting for the relevant factors in the multivariate model, RPR ≥0.19 was independently correlated with the 28-day all-cause mortality (hazard ratio, 2.74; 95% confidence interval, 1.46-5.15; P = 0.002). There was no nonlinear relationship between RPR and the risk of 28-day all-cause mortality ( P for overall association <0.001, P for nonlinear = 0.635). Similar results were observed for both the pneumonia and nonpneumonia subgroups and sensitivity analyses. Conclusions: The data promote the use of RPR as a valuable prognostic indicator for ARDS patients.

The Relation Between Red Blood Cell Distribution Width and Coronary Atherosclerotic Plaque Vulnerability Detected by Intracoronary Optical Coherence Tomography

BACKGROUND

A higher red blood cell distribution width (RDW) predicts major adverse cardiac events in patients with coronary artery disease (CAD). However, there are only a few studies regarding the relationship between RDW and vulnerable plaques. Thus, the purpose of the present study is to retrospectively explore the predictive value of the association between RDW and plaque vulnerability assessed by optical coherence tomography (OCT) in patients with cardiovascular (CV) diseases.

METHODS

This study included 35 patients with stable angina pectoris (SAP) and 70 patients with the acute coronary syndrome (ACS). We documented clinical features as well as peripheral RDW. Plaque vulnerability was determined by OCT. We defined thin-cap fibroatheroma (TCFA) as a lipid-rich plaque (fibrous cap <65 μm thick).

RESULTS

Plaque rupture was detected more frequently in patients with ACS compared with patients with SAP (62.9 vs. 2.9%, p<0.001, and the corresponding TCFA were 50.69±15.68 vs. 80.03±21.60 μm, p<0.001, respectively). A higher RDW was found in patients with ACS than in patients with SAP (p<0.001). A cut-off value of RDW >13.85% could detect ruptured plaque with a sensitivity of 72.3% and a specificity of 62%.

CONCLUSION

TCFA and plaque rupture were detected more frequently in patients with ACS compared with SAP. Elevated RDW was positively the predictive value of the association between plaque vulnerability.

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 cell distribution width is associated with cardiovascular risk in adults

Red cell distribution width (RDW) is a measure of erythrocyte size variability. Recent studies have shown that RDW is a predictive, and prognostic marker of mortality and cardiovascular (CVD) events in the general population and in CVD patients. This study aimed to investigate the association between RDW and CVD risk in a large sample of adults. A subsample of CVD free participants of the ELSA-Brasil cohort were included (n=4,481). In the cross-sectional approach, multiple regression analysis was used to investigate the association between RDW and the Framingham Risk Score (FRS). Linear mixed effect model evaluated whether baseline RDW predicted changes in CVD risk after about four-year follow up. Cross-sectional analysis showed that RDW was independently associated with FRS, participants in the fourth-quartile of RDW distribution had a 29% higher FRS than those in the first-quartile RDW (p<0.001). A longitudinal analysis revealed that RDW remained associated with increased FRS. In this large cohort of adult Brazilians, RDW was independently associated with increased CVD risk, as measured by the FRS, both at baseline and after four-year follow-up. However, RDW did not predict change in CVD risk in this short-term follow up.

Dynamic Changes in Red Cell Distribution Width Can Predict Major Adverse Cardiovascular Events after PCI in Patients with Unstable Angina Pectoris: A Retrospective Cohort Study

Background

The increased red cell distribution width (RDW) is related to a higher risk for cardiovascular disease (CVD). However, it is yet unclear whether the dynamic change of RDW is associated with the major adverse cardiovascular events (MACEs) for individual with CVD.

Methods and Results

A cohort study was conducted among 228 patients who had unstable angina (UA) and underwent PCI. RDW was measured preceding PCI and re-measured on the 16th week after PCI. The change of RDW values was defined as ΔRDW. The patients were divided into 3 groups in accordance with ΔRDW: improved, stable, and worsened RDW groups. The patients were followed up for 6 years, and MACE episodes were recorded. The survival analysis showed that the incidence of MACEs in stable RDW group was significantly lower than that in improved and worsened RDW groups. By the COX model, the risk of the occurrence of cardiovascular events in improved RDW group was 1.661 times higher than the risk in stable RDW group (HR =1.661, 95% CI: 1.583-2.880, p < 0.05) and the same situation was 3.307 times higher in worsened RDW group (HR =3.307, 95% CI: 1.830-5.041, p < 0.05).

Conclusion

The measurement of ΔRDW has potential to predict the MACEs in UA patients underwent PCI. The dynamic changes in RDW are associated with the outcome of CVD.

Vitamin C Plasma Levels Associated with Inflammatory Biomarkers, CRP and RDW: Results from the NHANES 2003–2006 Surveys

Although undisputed for its anti-inflammatory and immune system boosting properties, vitamin C remains an inconsistently investigated nutrient in the United States. However, subclinical inadequacies may partly explain increased inflammation and decreased immune function within the population. This secondary analysis cross-sectional study used the 2003–2006 NHANES surveys to identify more clearly the association between plasma vitamin C and clinical biomarkers of acute and chronic inflammation C-reactive protein (CRP) and red cell distribution width (RDW). From plasma vitamin C levels separated into five defined categories (deficiency, hypovitaminosis, inadequate, adequate, and saturating), ANOVA tests identified significant differences in means in all insufficient vitamin C categories (deficiency, hypovitaminosis, and inadequate) and both CRP and RDW in 7607 study participants. There were also statistically significant differences in means between sufficient plasma vitamin C levels (adequate and saturating categories) and CRP. Significant differences were not identified between adequate and saturating plasma vitamin C levels and RDW. Although inadequate levels of vitamin C may not exhibit overt signs or symptoms of deficiency, differences in mean levels identified between inflammatory biomarkers suggest a closer examination of those considered at risk for inflammatory-driven diseases. Likewise, the subclinical levels of inflammation presented in this study provide evidence to support ranges for further clinical inflammation surveillance.

Hemoglobin-to-Red-Cell Distribution Width Ratio Is a Novel Predictor of Long-Term Patient Outcomes After Percutaneous Coronary Intervention: A Retrospective Cohort Study

BACKGROUND

The hemoglobin level and red cell distribution width (RDW) have been linked to the prognosis of coronary atherosclerotic heart disease (CAHD). However, the relationship between the ratio of hemoglobin to the RDW (HRR) and clinical outcomes after percutaneous coronary intervention (PCI) is not known. Here, we explored the impact of the HRR on clinical outcomes after PCI.

METHODS

In our study, we selected 6,046 CAHD patients with PCI hospitalized in the First Affiliated Hospital of Xinjiang Medical University from 2008 to 2016. The patients were grouped according to their HRR ratio: group A (HRR < 10.25, n = 2,344) and group B (HRR ≥ 10.25, n = 3,702). The difference in clinical outcomes between the two groups was compared. Patients were followed up for 35.9 ± 22.6 months.

RESULTS

Three hundred nine patients died during follow-up. These included 166 patients (7.1%) in the HRR < 10.25 group and 143 patients (3.9%) in the HRR ≥ 10.25 group (P < 0.001). The incidences of cardiogenic death (5.7 vs. 3.2%) and major cardiovascular adverse events (16.5 vs. 12.9%) also differed significantly between the groups (both Ps < 0.001). Analysis using the multivariate Cox proportional hazard model found a significant association between a decreased HRR and post-PCI mortality (all-cause death, adjusted HR: 1.479, 95% CI: 1.156-1.893, p = 0.002; cardiac death, adjusted HR: 1.470, 95% CI: 1.116-1.936, p = 0.006).

CONCLUSION

The HRR is predictive of post-PCI mortality among CAHD patients.

Omega-3 index is directly associated with a healthy red blood cell distribution width

Low red blood cell (RBC) membrane content of EPA and DHA, i.e., the omega-3 index (O3I), and elevated RBC distribution width (RDW) are risk factors for all-cause mortality. O3I and RDW are related with membrane fluidity and deformability. Our objective was to determine if there is a relationship between O3I and RDW in healthy adults. Subjects without inflammation or anemia, and with values for O3I, RDW, high-sensitivity C-reactive protein (CRP), body mass index (BMI), age and sex were identified (n = 25,485) from a clinical laboratory dataset of  > 45,000 individuals. RDW was inversely associated with O3I in both sexes before and after (both p < 0.00001) adjusting models for sex, age, BMI and CRP. Stratification by sex revealed a sex-O3I interaction with the RDW-O3I slope (p < 0.00066) being especially steep in females with O3I ≤ 5.6%. In healthy adults of both sexes, the data suggested that an O3I of > 5.6% may help maintain normal RBC structural and functional integrity.

RDW-based clinical score to predict long-term survival in community-acquired pneumonia: a European derivation and validation study

An excess long-term mortality has been observed in patients who were discharged after a community-acquired pneumonia (CAP), even after adjusting for age and comorbidities. We aimed to derive and validate a clinical score to predict long-term mortality in patients with CAP discharged from a general ward. In this retrospective observational study, we derived a clinical risk score from 315 CAP patients discharged from the Internal Medicine ward of Cuneo Hospital, Italy, in 2015-2016 (derivation cohort), which was validated in a cohort of 276 patients discharged from the pneumology service of the Barakaldo Hospital, Spain, from 2015 to 2017, and from two internal medicine wards at the Turin University and Cuneo Hospital, Italy, in 2017. The main outcome was the 18-month follow-up all-cause death. Cox multivariate analysis was used to identify the predictive variables and develop the clinical risk score in the derivation cohort, which we applied in the validation cohort. In the derivation cohort (median age: 79 years, 54% males, median CURB-65 = 2), 18-month mortality was 32%, and 18% in the validation cohort (median age 76 years, 55% males, median CURB-65 = 2). Cox multivariate analysis identified the red blood cell distribution width (RDW), temperature, altered mental status, and Charlson Comorbidity Index as independent predictors. The derived score showed good discrimination (c-index 0.76, 95% CI 0.70-0.81; and 0.83, 95% CI 0.78-0.87, in the derivation and validation cohort, respectively), and calibration. We derived and validated a simple clinical score including RDW, to predict long-term mortality in patients discharged for CAP from a general ward.

The associations between red cell distribution width and lung function measures in a general population

BACKGROUND

Red cell distribution width (RDW) reflects heterogeneity of the erythrocyte volumes. High RDW is a novel risk marker, which has been associated with mortality and morbidity both from cardiovascular and respiratory diseases, but the association between RDW and measures of lung function in the general population remains unclear.

METHODS

The associations of RDW with spirometry, diffusing capacity (D_LCO) and impulse oscillometry (IOS) were investigated among 5767, 5496 and 5598 subjects (aged 50-64 years), respectively, from the Swedish CArdioPulmonary bioImage Study (SCAPIS). Multiple linear regression and general linear models were performed to examine the relationships of lung function measures and RDW, with adjustment for potential confounding factors.

RESULTS

Forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and FEV₁/FVC were significantly and inversely associated with RDW after multivariate adjustments. For 1- standard deviation (SD) increase in RDW, FEV₁ decreased with 0.034 L (95%CI: -0.046 to -0.022 L), p < 0.001; FVC with 0.031 L (95%CI: -0.045 to -0.017 L), p < 0.001; and FEV₁/FVC with 0.003 (95%CI: -0.004 to -0.001), p = 0.002. Significant associations of RDW and D_LCO were only found among smokers. For IOS, pulmonary reactance rather than resistance was significantly associated with RDW: X₅ decreased 0.002 kPa/(L/s) (95%CI: -0.003 to -0.0002 kPa/(L/s)), p = 0.025, per 1-SD higher RDW.

CONCLUSIONS

We found significant negative associations between RDW and measures of lung function. However, the effect sizes are small and RDW is not likely to be a sensitive marker of impaired lung function in middle-aged individuals from the general population.

Association Between Red Blood Cell Distribution Width and Thyroid Function

AIM

Red blood cell distribution width (RDW) is an important parameter with broad biological implications. However, the study investigating the association between RDW and thyroid function remains sparse and inconsistent. We aimed to investigate the association between RDW and thyroid function in the US population.

METHODS

A cross-sectional analysis was performed using the data from the National Health and Nutrition Examination Survey (NHANES) conducted from 2007 to 2010. The thyroid parameters investigated were mainly free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), antithyroglobulin antibody (TgAb), and antithyroperoxidase antibody (TPOAb). In the 6,895 adults aged 18 years or older, logistic regression modeling was applied to estimate the association between RDW quartiles and thyroid parameters. Smooth curve fittings and generalized additive models were then performed to address the nonlinear relationship.

RESULTS

The association between RDW and TSH followed a J-shaped curve, and a significant positive relationship existed in the 12.5%-17.5% range of RDW (β  = 0.350, 95% confidence interval (CI): 0.225 to 0.474), which was prominent in females. We further demonstrated a negative association (β = -0.018, 95% CI: -0.030 to -0.005) between RDW and fT3. Moreover, elevated RDW was more likely to be subclinical hypothyroidism. However, there was no obvious association between RDW and fT4.

CONCLUSION

This study confirmed a significant association between RDW and TSH, and future studies are needed to elucidate the underlying mechanisms of the peculiar RDW-fT3 relationship. RDW may be a significant clinical marker of subclinical hypothyroidism.

Red blood cell distribution width in addition to N-terminal prohormone of B-type natriuretic peptide concentration improves assessment of risk of cardiovascular events in adult patients with congenital heart disease

BACKGROUND

Red blood cell distribution width (RDW) is a predictor of adverse outcomes in patients with heart disease.

AIM

To establish predictors of high RDW values in patients with congenital heart disease (CHD), and their relationship with cardiovascular events.

METHODS

Overall, 561 patients with stable CHD who attended a single outpatient clinic and a matched control population of 2128 patients were studied. Exclusion criteria were renal failure, anaemia, receiving iron therapy and cyanosis. Blood tests included glucose, creatinine, iron, apoferritin, liver enzymes and a complete blood count. C-reactive protein and N-terminal prohormone of B-type natriuretic peptide (NT-pro-BNP) concentrations were also measured in patients with CHD. Major adverse cardiac events (MACE) were defined as cardiovascular/total mortality, arterial thrombotic events, arrhythmias, major bleedings, pulmonary embolism or heart failure needing hospital admission.

RESULTS

The median age in patients with CHD was 23 (17-36) years and the median follow-up time was 5.8 (3.2-8.7) years; 103 (4.8%) controls and 40 (7.1%) patients with CHD had an RDW>15% (P=0.032). During follow-up, MACE were reported in 48 patients. CHD of great complexity, cardiovascular risk factors, low haemoglobin concentration and high NT-pro-BNP concentration were risk factors for an RDW>15%. Kaplan-Meier analysis showed a significantly worse cardiovascular outcome in patients with CHD with an RDW>15% (P<0.001). The multivariable survival analysis determined that age, CHD of great complexity, high NT-pro-BNP concentration and an RDW>15% were independent predictive factors for MACE.

CONCLUSION

RDW and NT-pro-BNP concentration are independent analytical predictors of MACE in patients with CHD.

Red Cell Distribution Width as a Predictor of Functional Outcome in Rehabilitation of Older Stroke Patients

BACKGROUND

Red cell distribution width (RDW) is a prognostic marker in vascular diseases. While increased RDW predicts mortality and outcomes after ischemic stroke, evidence regarding its prognostic significance in stroke rehabilitation is lacking. Thus, the present study investigated the relationship of RDW with stroke, orthopedic, and deconditioning rehabilitation outcomes.

METHODS

This prospective comparative study included three groups (stroke, orthopedic, and deconditioning) of older adult patients hospitalized for rehabilitation. The patients in each group were divided into two subgroups according to whether they had high (>14.5%) or normal (≤14.5%) RDW levels on admission. Functional outcome was assessed by total and motor FIM (Functional Independence Measure) score changes and efficiency at admission and on discharge.

RESULTS

Of the 234 eligible patients, 108 (46.2%) had high RDW. Of the 50 stroke rehabilitation patients, 13 (26%) had high RDW. FIM change and efficiency scores were significantly lower in patients with high RDW only in the stroke rehabilitation group. However, multiple linear regression analysis showed that high RDW was not independently associated with total and motor FIM gain or total and motor FIM efficiency.

CONCLUSION

High RDW levels on admission to rehabilitation were associated with poor rehabilitation outcome in stroke patients but were not an independent risk factor for rehabilitation outcomes.

Prognostic value of pulmonary hypertension in pre-dialysis chronic kidney disease patients

BACKGROUND

Pulmonary hypertension is common in chronic kidney disease (CKD) patients. However, the prognostic value of pulmonary hypertension in Chinese predialytic CKD patients is rarely reported. We evaluated the relevant factors and prognostic value of pulmonary hypertension in CKD patients.

METHODS

This retrospective cohort study enrolled 1092 predialytic patients from The Third Affiliated Hospital of Sun Yat-Sen University from May 1st, 2011, to December 31st, 2016. Data of interest were retrieved from electronic medical records. Pulmonary hypertension was defined as pulmonary arterial systolic pressure (PASP) ≥ 35 mmHg by echocardiology. All participants were followed from the date of the first echocardiography examination. The primary endpoints were all-cause mortality and cardiovascular mortality. The secondary endpoint was end-stage renal disease (ESRD) defined as starting renal replacement therapy.

RESULTS

The prevalence of pulmonary hypertension was 15.9% in the study population. For CKD stage 1, 2, 3a, 3b, 4 and 5, the prevalence was 6.0%, 9.6%, 17.2%, 13.3%, 20.7% and 26.6%, respectively. Older age, lower left ventricular ejection fraction, anemia and higher pulse pressure were independently associated with pulmonary hypertension in CKD patients. In multivariate Cox regression analysis, pulmonary hypertension was the independent risk factor for cardiovascular mortality, but not of all-cause mortality and ESRD.

CONCLUSIONS

Pulmonary hypertension is not rare in early CKD patients. Patients with older age, anemia, higher pulse pressure and compromised heart function were more likely to comorbid pulmonary hypertension. Pulmonary hypertension maybe a sign of worse cardiovascular outcome in CKD patients.

Red blood cell distribution width is associated with mortality risk in patients with acute respiratory distress syndrome based on the Berlin definition: A propensity score matched cohort study

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe inflammatory disorder of the lungs and is associated with oxidative damage. However, red blood cell distribution width (RDW), as an indicator of body response to inflammation and oxidative stress, has not been studied for its relationship with ARDS as diagnosed by the Berlin definition.

OBJECTIVES

To examine the value of RDW in predicting the prognosis of in patients with ARDS.

METHODS

This is a retrospective study based on the Medical Information Mart for Intensive Care III (MIMIC-III) database. Berlin-defined ARDS patients using mechanical ventilation for more than 48 hours were selected using structured query language. The primary statistical methods were propensity score matching and sensitivity analysis, including an inverse probability weighting model to ensure the robustness of our findings.

RESULTS

A total of 529 intensive care unit (ICU) patients with ARDS according to the Berlin definition were enrolled in the study. The adjusted OR showed an adverse effect between the higher RDW group and 30-day mortality [OR 2.33, 95% CI (1.15-4.75), P=0.019]. However, we found that length of ICU stay was not related to RDW (P=0.167), and in the anaemia group, RDW was poorly predictive of 30-day mortality (P=0.307).

CONCLUSION

In unselected ARDS patients, higher RDW was associated with higher 30-day mortality rate. Further investigation is required to validate this relationship with prospectively collected data.

A cross-sectional comparison between cardiorespiratory fitness, level of lesion and red blood cell distribution width in adults with chronic spinal cord injury

OBJECTIVES

To assess; (1) differences in red blood cell distribution width between individuals with chronic (>1year), motor-complete cervical (n=21), upper-thoracic (n=27) and thoracolumbar (n=15) spinal cord injury and, (2) associations between red blood cell distribution width and cardiorespiratory fitness.

DESIGN

Prospective multi-center, cross-sectional study.

METHODS

Peak oxygen uptake was determined using an upper-body arm-crank exercise test to volitional exhaustion and red blood cell distribution width was measured using an automated hematology system.

RESULTS

There were significant (p<0.009) differences between groups classified by level of injury in absolute and relative peak oxygen uptake, peak power output and red blood cell distribution width. A significant (p<0.001) large negative association (r = -0.524) was found between relative peak oxygen uptake and red blood cell distribution width. Unbiased recursive partitioning, while revealing study site specific differences in red blood cell distribution width, identified homogenous subgroups based specifically on cardiorespiratory fitness irrespective of additional demographic and injury characteristics.

CONCLUSION

The strong negative association between cardiorespiratory fitness and red blood cell distribution width in individuals with paraplegia parallel those previously observed in non-disabled individuals. Higher red blood cell distribution width values are an independent risk factor for increased cardiovascular mortality, heart failure, and coronary heart disease and may reflect several underlying exacerbated metabolic responses such as oxidative stress and systemic inflammation. These data emphasize the importance of maintaining a high aerobic capacity following spinal cord injury.

Cardiovascular, electrophysiologic, and hematologic effects of omega-3 fatty acids beyond reducing hypertriglyceridemia: as it pertains to the recently published REDUCE-IT trial

Heart disease continues to affect health outcomes globally, accounting for a quarter of all deaths in the United States. Despite the improvement in the development and implementation of guideline-directed medical therapy, the risk of adverse cardiac events remains substantially high. Historically, it has been debated whether omega-3 polyunsaturated fatty acids provide clinical benefit in cardiac disease. The recently published REDUCE-IT trial demonstrated a statistically significant absolute risk reduction of 4.8% in its primary endpoint (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or unstable angina) with the use of icosapent ethyl, which is a highly purified eicosapentaenoic acid (EPA) ethyl ester. However, the mechanism of action of omega-3 fatty acids is not commonly discussed. Moreover, the use of EPA was not without risk, as the incidence of atrial fibrillation was increased along with a trend towards increased bleeding risk. Thus, our aim is to help explain the function of purified EPA ethyl ester, especially at the molecular level, which will ultimately lead to a better understanding of their clinically observable effects.

Red blood distribution width and heart transplantation: any predictive role on patient outcome?

BACKGROUND

Red blood cell distribution width (RDW) has been emerging as a strong predictor of mortality among patients with cardiovascular disease. The aim of this study was to verify if RDW is able to predict survival after heart transplantation (HTx).

METHODS

Two hundred and eighteen recipients who underwent HTx between 2000 and 2013 were classified into three groups according to the pre-HTx RDW tertile values (14.6 and 16.4%), and their outcomes were compared. Mean follow-up was 6.6 ± 4.2 years.

RESULTS

RDW correlated with other markers of chronic pathological conditions, such as the Index for Mortality Prediction after Cardiac Transplantation (IMPACT) score (P = 0.002) and Charlson Comorbidity Index (P < 0.001), and with creatinine levels (P = 0.007), previous cardiac surgery (P < 0.001), diabetes mellitus (P = 0.02), haemoglobin value (P = 0.004), pulmonary capillary wedge and central venous pressures (P = 0.019 and 0.01, respectively), systolic and mean pulmonary artery pressures (P = 0.002 and 0.014, respectively). The rate of 30-day mortality from the lowest to the highest RDW tertile was 1.4, 4 and 9% (P = 0.02), respectively.Long-term mortality correlated at multivariate analysis with recipient age [hazard ratio 1.06, 95% confidence interval (95% CI) 1.02-1.09], donor age (hazard ratio 1.02, 95% CI 1.0-1.04) and RDW (hazard ratio 1.13, 95% CI 1.04-1.23). The survival probability at 4, 8 and 12 years was 90, 84 and 74% for recipients with RDW less than 14.6%, while it was 72, 60 and 42% for recipients with RDW more than 16.4% (hazard ratio 3.29, 95% CI 1.74-6.24). No differences were found between causes of death.

CONCLUSION

RDW correlated with survival in HTx recipients. This marker of blood cell size may represent a surrogate of disease and a helpful tool in the risk-assessment process.

Red blood cell distribution width predicts long-term outcomes in sepsis patients admitted to the intensive care unit

BACKGROUND

Although some underpowered studies have proven that increased red blood cell distribution width (RDW) may be associated with short-term prognosis of sepsis, the long-term prognostic value of RDW remains largely unknown.

METHODS

This retrospective observational study was based on the Medical Information Mart for Intensive Care III (MIMIC III), a large critical care database. Baseline RDW and conventional disease severity scores were extracted along with data on 4-year mortality, of adult patients with severe sepsis upon first admission to the intensive care unit (ICU). The prognostic value of RDW was analyzed with Kapan-Meier cure, Cox model, receiver operating characteristic (ROC) curve analysis, net reclassification index (NRI) and integrated discriminatory index (IDI).

RESULTS

A total of 4264 subjects were included. The area under ROC curve of RDW for predicting 4-year mortality was 0.64 (95% CI: 0.63-0.66). In multivariable Cox model, increased RDW was independently associated with all-cause mortality, irrespective of anemia. With conventional severity scores as reference, RDW had continuous NRI comprised between 0.18 and 0.20, and IDI comprised between 0.30 and 0.40.

CONCLUSION

RDW values significantly predicts long-term all-cause mortality in critically ill patients with severe sepsis beyond conventional severity scores.

Preoperative Red Cell Distribution Width and 30-day mortality in older patients undergoing non-cardiac surgery: a retrospective cohort observational study

Increased red cell distribution width (RDW) is associated with poorer outcomes in various patient populations. We investigated the association between preoperative RDW and anaemia on 30-day postoperative mortality among elderly patients undergoing non-cardiac surgery. Medical records of 24,579 patients aged 65 and older who underwent surgery under anaesthesia between 1 January 2012 and 31 October 2016 were retrospectively analysed. Patients who died within 30 days had higher median RDW (15.0%) than those who were alive (13.4%). Based on multivariate logistic regression, in our cohort of elderly patients undergoing non-cardiac surgery, moderate/severe preoperative anaemia (aOR 1.61, p = 0.04) and high preoperative RDW levels in the 3rd quartile (>13.4% and ≤14.3%) and 4th quartile (>14.3%) were significantly associated with increased odds of 30-day mortality - (aOR 2.12, p = 0.02) and (aOR 2.85, p = 0.001) respectively, after adjusting for the effects of transfusion, surgical severity, priority of surgery, and comorbidities. Patients with high RDW, defined as >15.7% (90th centile), and preoperative anaemia have higher odds of 30-day mortality compared to patients with anaemia and normal RDW. Thus, preoperative RDW independently increases risk of 30-day postoperative mortality, and future risk stratification strategies should include RDW as a factor.