Yao-Peng Hsieh

Predictors of Peritonitis and the Impact of Peritonitis on Clinical Outcomes of Continuous Ambulatory Peritoneal Dialysis Patients in Taiwan—10 Years’ Experience in a Single Center

♦ Objective: Peritoneal dialysis (PD) has become more prevalent as a treatment modality for end-stage renal disease, and peritonitis remains one of its most devastating complications. The aim of the present investigation was to examine the frequency and predictors of peritonitis and the impact of peritonitis on clinical outcomes. ♦ Methods: Our retrospective observational cohort study enrolled 391 patients who had been treated with continuous ambulatory PD (CAPD) for at least 90 days. Relevant demographic, biochemical, and clinical data were collected for an analysis of CAPD-associated peritonitis, technique failure, drop-out from PD, and patient mortality. ♦ Results: The peritonitis rate was 0.196 episodes per patient-year. Older age (>65 years) was the only identified risk factor associated with peritonitis. A multivariate Cox regression model demonstrated that technique failure occurred more often in patients experiencing peritonitis than in those free of peritonitis (p < 0.001). Kaplan-Meier analysis revealed that the group experiencing peritonitis tended to survive longer than the group that was peritonitis-free (p = 0.11). After multivariate adjustment, the survival advantage reached significance (hazard ratio: 0.64; 95% confidence interval: 0.46 to 0.89; p = 0.006). Compared with the peritonitis-free group, the group experiencing peritonitis also had more drop-out from PD (p = 0.03). ♦ Conclusions: The peritonitis rate was relatively low in the present investigation. Elderly patients were at higher risk of peritonitis episodes. Peritonitis independently predicted technique failure, in agreement with other reports. However, contrary to previous studies, all-cause mortality was better in patients experiencing peritonitis than in those free of peritonitis. The underlying mechanisms of this presumptive “peritonitis paradox” remain to be clarified.

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

Background Recently, accumulating evidence has demonstrated that RDW independently predicts clinically important outcomes in many populations. However, the role of RDW has not been elucidated in chronic kidney disease (CKD) patients. We conducted the present study with the aim to evaluate the predictive value of RDW in CKD patients. Methods A retrospective observational cohort study of 1075 stage 3–5 CKD patients was conducted in a medical center. The patients’ baseline information included demographic data, laboratory values, medications, and comorbid conditions. The upper limit of normal RDW value (14.9%) was used to divide the whole population. Multivariate Cox regression analysis was used to determine the independent predictors of mortality. Results Of the 1075 participants, 158 patients (14.7%) died over a mean follow-up of approximately 2.35 years. The crude mortality rate was significantly higher in the high RDW group (high RDW group, 22.4%; low RDW group 11%, p <0.001). From the adjusted model, the high RDW group was correlated with a hazard ratio of 2.19 for overall mortality as compared with the low RDW group (95% CI = 1.53–3.09, p<0.001). In addition, the high RDW group was also associated with an increased risk for cardiovascular disease (HR = 2.28, 95% CI = 1.14–4.25, p = 0.019) and infection (HR = 1.9, 95% CI = 1.15–3.14, p = 0.012)) related mortality in comparison with the low RDW group. Conclusions In stage 3–5 CKD patients, RDW was associated with patient mortality of all-cause, cardiovascular disease and infection. RDW should be considered as a clinical predictor for mortality when providing healthcare to CKD patients.

THE NEGATIVE IMPACT OF EARLY PERITONITIS ON CONTINUOUS AMBULATORY PERITONEAL DIALYSIS PATIENTS

♦ Background: Peritonitis rate has been reported to be associated with technique failure and overall mortality in previous literatures. However, information on the impact of the timing of the first peritonitis episode on continuous ambulatory peritoneal dialysis (CAPD) patients is sparse. The aim of this research is to study the influence of time to first peritonitis on clinical outcomes, including technique failure, patient mortality and dropout from peritoneal dialysis (PD). ♦ Methods: A retrospective observational cohort study was conducted over 10 years at a single PD unit in Taiwan. A total of 124 patients on CAPD with at least one peritonitis episode comprised the study subjects, which were dichotomized by the median of time to first peritonitis into either early peritonitis patients or late peritonitis patients. Cox proportional hazard model was used to analyze the correlation of the timing of first peritonitis with clinical outcomes. ♦ Results: Early peritonitis patients were older, more diabetic and had lower serum levels of creatinine than the late peritonitis patients. Early peritonitis patients were associated with worse technique survival, patient survival and stay on PD than late peritonitis patients, as indicated by Kaplan-Meier analysis (log-rank test, p = 0.04, p < 0.001, p < 0.001, respectively). In the multivariate Cox regression model, early peritonitis was still a significant predictor for technique failure (hazard ratio (HR), 0.54; 95% confidence interval (CI), 0.30 - 0.98), patient mortality (HR, 0.34; 95% CI, 0.13 - 0.92) and dropout from PD (HR, 0.50; 95% CI, 0.30 - 0.82). In continuous analyses, a 1-month increase in the time to the first peritonitis episode was associated with a 2% decreased risk of technique failure (HR, 0.98; 95% CI, 0.97 - 0.99), a 3% decreased risk of patient mortality (HR, 0.97; 95% CI, 0.95 - 0.99), and a 2% decreased risk of dropout from PD (HR, 98%; 95% CI, 0.97 - 0.99). Peritonitis rate was inversely correlated with time to first peritonitis according to the Spearman analysis (r = -0.64, p < 0.001). ♦ Conclusions: Time to first peritonitis is significantly correlated with clinical outcomes of peritonitis patients with early peritonitis patients having poor prognosis. Patients with shorter time to first peritonitis were prone to having a higher peritonitis rate.

The role of uric acid in chronic kidney disease patients.

Chronic kidney disease (CKD) is always associated with hyperuricaemia. However, the studies evaluating the clinical implications of hyperuricaemia have shown conflicting results in these patients.

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

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.

U-shaped relationship between uric acid and residual renal function decline in continuous ambulatory peritoneal dialysis patients.

There is little information on the relationship between uric acid (UA) and residual renal function (RRF) in continuous ambulatory peritoneal dialysis (CAPD). The aim of this research is to study the influence of UA on RRF decline in CAPD patients.

Relationship between uric acid and technique failure in patients on continuous ambulatory peritoneal dialysis: a long-term observational cohort study

Objectives Uric acid (UA) is the product of purine or nucleotide metabolism via the pathway of xanthine oxidase or xanthine dehydrogenase. Although epidemiological studies assessing the role of UA in cardiovascular disease or mortality have produced inconsistent results, the correlation between UA and technique failure in patients on continuous ambulatory peritoneal dialysis (CAPD) remains to be assessed. Design A retrospective cohort study. Setting Patients starting CAPD between 2001 and 2009 in a single centre in Taiwan. Participants A total of 371 patients on CAPD. Primary outcome measures All-cause and peritonitis-related technique failure. Results A cohort of 371 participants (43.9% male) was enrolled in the study with a mean age of 55.7±15.9 years at the start of CAPD. During the study period, technique failure occurred in 41 (34.4%) patients in the hyperuricaemia group compared with 49 (19.4%) in the normouricaemia group (p=0.003). In the multivariate Cox regression models, hyperuricaemia at baseline was significantly associated with both a higher risk of technique failure (HR 1.24; 95% CI 1.09 to 1.42, p=0.001) and peritonitis-related technique failure (HR 1.29; 95% CI 1.07 to 1.57, p=0.008). Conclusions UA was shown to be associated with all-cause and peritonitis-related technique failure in our study. Patients on CAPD with hyperuricaemia should be closely monitored and strategies of increasing survival on CAPD should be taken.

The prognostic value of interaction between mean corpuscular volume and red cell distribution width in mortality in chronic kidney disease

Recently, both red cell distribution width (RDW) and mean corpuscular volume (MCV) have been associated with unfavorable outcomes in several medical conditions. Therefore, we conducted this retrospective study of 1075 patients with stage 3–5 chronic kidney disease to investigate whether interactions between RDW and MCV influence the risk of mortality. These patients were divided into four groups: group A (n = 415), RDW ≤ 14.9% and MCV ≤ 91.6 fL; group B (n = 232), RDW > 14.9% and MCV ≤ 91.6 fL; group C (n = 307), RDW ≤ 14.9% and MCV > 91.6 fL; and group D (n = 121), RDW > 14.9% and MCV > 91.6 fL. The adjusted hazard ratio (HR) of all-cause mortality for group B versus group A was 1.44 (95% confidence interval [CI], 1.14–2.12, p = 0.02), group C versus group A 2.14 (95% CI, 1.31–3.48, p = 0.002), and group D versus group A 5.06 (95% CI, 3.06–8.37, p < 0.001). There was a multiplicative interaction between MCV and RDW in predicting patient mortality. The use of RDW in conjunction with MCV may improve healthcare by identifying those at an increased risk for mortality compared with the use of either RDW or MCV alone.

Association between End-Stage Renal Disease and Incident Diabetes Mellitus—A Nationwide Population-Based Cohort Study

Background: Glucose is one of the constituents in hemodialysates and peritoneal dialysates. How the dialysis associates with the incident diabetes mellitus (DM) remains to be assessed. Methods: The claim data of end-stage renal disease (ESRD) patients who initiated dialysis from and a cohort of matched non-dialysis individuals from 2000 to 2013 were retrieved from the Taiwan National Health Insurance Research Database to examine the risk of incident DM among patients on hemodialysis (HD) and peritoneal dialysis (PD). Predictors of incident DM were determined for HD and PD patients using Fine and Gray models to treat death as a competing event, respectively. Results: A total of 2228 patients on dialysis (2092 HD and 136 PD) and 8912 non-dialysis individuals were the study population. The PD and HD patients had 12 and 97 new-onset of DM (incidence rates of 15.98 and 8.69 per 1000 patient-years, respectively), while the comparison cohort had 869 DM events with the incidence rate of 15.88 per 1000 patient-years. The multivariable-adjusted Cox models of Fine and Gray method showed that the dialysis cohort was associated with an adjusted hazard ratio (HR) of 0.49 (95% CI 0.39–0.61, p value < 0.0001) for incident DM compared with the comparison cohort. The adjusted HR of incident DM was 0.46 (95% CI 0.37–0.58, p value < 0.0001) for HD and 0.84 (95% CI 0.47–1.51, p value = 0.56) for PD. Conclusions: ESRD patients were associated with a lower risk of incident DM. HD was associated with a lower risk of incident DM, whereas PD was not.

Mean Corpuscular Volume and Mortality in Patients with CKD

BACKGROUND AND OBJECTIVES Mean corpuscular volume is the measure of the average size of the circulatory erythrocyte, and it is principally used as an index for the differential diagnosis of anemia. Recently, mean corpuscular volume has been associated with mortality in many clinical settings. However, the association of mean corpuscular volume with mortality in patients with CKD has not been fully addressed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted a retrospective observational cohort study of 1439 patients with stages 3-5 CKD and baseline mean corpuscular volume values from 2004 to 2012 in a medical center. The study cohort was divided into the high-mean corpuscular volume group and the low-mean corpuscular volume group by the median value (90.8 fl) of mean corpuscular volume. The baseline patient information included demographic data, laboratory parameters, medications, and comorbid conditions. The independent association of mean corpuscular volume with mortality was examined using multivariate Cox regression analysis. RESULTS Of the 1439 participants, 234 patients (16.2%) died during a median follow-up of 1.9 years (interquartile range, 1.1-3.8 years). The crude overall mortality rate was significantly higher in the high-mean corpuscular volume group (high-mean corpuscular volume group, 22.7%; low-mean corpuscular volume group, 9.7%; P<0.001). In the fully adjusted models, the high-mean corpuscular volume group was associated with higher risks of all-cause mortality (hazard ratio, 2.19; 95% confidence interval, 1.62 to 2.96; P<0.001), cardiovascular mortality (hazard ratio, 3.57; 95% confidence interval, 1.80 to 7.06; P<0.001), and infection-related mortality (hazard ratio, 2.22; 95% confidence interval, 1.41 to 3.49; P=0.001) compared with the low-mean corpuscular volume group. CONCLUSIONS In patients with stages 3-5 CKD, mean corpuscular volume was associated with all-cause mortality, cardiovascular disease mortality, and infection-associated mortality, independent of other factors. The underlying pathophysiologic mechanisms warrant additional investigation.