Association between red cell distribution width and mortality in patients undergoing continuous ambulatory peritoneal dialysis

Abstract

Although red cell distribution width (RDW) has emerged as a biomarker of clinical prognostic value across a variety of clinical settings in the last two decades, limited evidence is available for its role in end-stage renal disease. We enrolled 313 incident patients undergoing continuous ambulatory peritoneal dialysis (CAPD) in this retrospective observational study from 2006 to 2015. In the fully adjusted model of Cox regression analysis, the adjusted hazard ratios for the high RDW group versus the low RDW group were 2.58 (95% confidence interval (CI) = 1.31–5.09, p = 0.006) and 3.48 (95% CI = 1.44–8.34, p = 0.006) for all-cause and cardiovascular disease (CVD)-related mortality, respectively. Based on area under the receiver operating characteristic curve (AUC) analysis, RDW (AUC = 0.699) had a stronger predictive value for all-cause and CVD-related mortality than other biological markers including hemoglobin (AUC = 0.51), ferritin (AUC = 0.584), iron saturation (AUC = 0.535), albumin (AUC = 0.683) and white blood cell count (AUC = 0.588). Given that RDW is a readily available hematological parameter without the need for additional cost, we suggest that it can be used as a valuable index to stratify the risk of mortality beyond a diagnosis of anemia.

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

“…The largest of these studies investigated a cohort of 1293 incident PD patients and observed that baseline RDW 15.5% (reference RDW <15.5%) was associated with a 60% higher risk of CV mortality, whereas the relationship with all-cause mortality showed a higher, yet attenuated risk [HR 1.27 (95% CI 0.93-1.75)] [16]. Similarly, in smaller cohorts of <500 PD patients each, Hsieh et al [18] observed a higher risk of all-cause and CV mortality with baseline RDW 15.3% (reference RDW <15.3%), and Sun et al [17] reported an almost 3-fold higher risk of all-cause mortality for every unit increase in baseline RDW. Like these studies, we too observed that greater baseline RDW was associated with higher risks of both all-cause and CV mortality in incident PD patients.…”

“…Although a majority of end-stage renal disease (ESRD) patients initiate treatment with HD, a growing number of patients have turned to peritoneal dialysis (PD) as the modality of choice in renal replacement therapy [15]. To date, there have only been a few studies that have investigated the association of RDW with mortality in PD patients [16][17][18]; one study found that RDW 15.5% was associated with higher CV mortality, yet an attenuated risk of all-cause mortality [16], and two other studies reported that higher RDW (15.3%, and per 1% increase, respectively) was associated with greater all-cause mortality risk [17,18]. However, each of these studies centered on smaller cohorts of Asian patients (<1300 patients each) and only investigated baseline RDW values.…”

“…In all analyses, RDW was categorized into five groups: <13.5, 13.5-<14.5, 14.5-<15.5, 15.5-<16.5 and 16.5%. The RDW categories as well as the reference of RDW (14.5-<15.5%) were chosen, considering the median of the cohort and prior studies [16][17][18].…”

“…It has been suggested that an increase in RDW in ESRD patients may be attributed to inflammation [26,27]. The inflammatory condition, which is prevalent among ESRD patients, including PD patients, may increase RDW and anisocytosis through impaired iron metabolism and declining erythropoietin response, thus leading to the circulation of immature erythrocytes and ineffective erythropoiesis, and possibly resulting in a greater risk of mortality and morbidity [2,18,28]. Moreover, higher RDW may be the result of increased oxidative and inflammatory stress stemming from the release of proinflammatory cytokines [29].…”

Application of instant messaging software in the follow‐up of patients using peritoneal dialysis, a randomised controlled trial

“…However, with the drastic increase in the number of patients undergoing PD and the limited number of PD specialists, the three follow‐up methods listed above may cause a disconnection between family and hospital, between outpatients and the ward, and between other links, which will affect patients’ treatment quality. The most recent International Society for Peritoneal Dialysis (ISPD) guideline shows that PD technology is becoming mature (Hurst, ); however, at present, due to the lack of professional personnel, the promotion of health education and follow‐up education is insufficient (Chen et al., ; Figueiredo et al., ; Grieff, Mamo, Scroggins, & Kurchin, ; Hsieh, Tsai, Chang, Kor, & Lin, ; Hurst, ). Therefore, novel methods are required to improve the clinical outcomes and satisfaction for PD patients.…”