Hye Min Jang

Survival advantage of peritoneal dialysis relative to hemodialysis in the early period of incident dialysis patients: a nationwide prospective propensity-matched study in Korea.

Background The impact of dialysis modality on survival is still somewhat controversial. Given possible differences in patients’ characteristics and the cause and rate of death in different countries, the issue needs to be evaluated in Korean cohorts. Methods A nationwide prospective observational cohort study (NCT00931970) was performed to compare survival between peritoneal dialysis (PD) and hemodialysis (HD). A total of 1,060 end-stage renal disease patients in Korea who began dialysis between September 1, 2008 and June 30, 2011 were followed through December 31, 2011. Results The patients (PD, 30.6%; HD, 69.4%) were followed up for 16.3±7.9 months. PD patients were significantly younger, less likely to be diabetic, with lower body mass index, and larger urinary volume than HD patients. Infection was the most common cause of death. Multivariate Cox regression with the entire cohort revealed that PD tended to be associated with a lower risk of death compared to HD [hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.36–1.08]. In propensity score matched pairs (n = 278 in each modality), cumulative survival probabilities for PD and HD patients were 96.9% and 94.1% at 12 months (P = 0.152) and 94.3% and 87.6% at 24 months (P = 0.022), respectively. Patients on PD had a 51% lower risk of death compared to those on HD (HR 0.49, 95% CI 0.25–0.97). Conclusions PD exhibits superior survival to HD in the early period of dialysis, even after adjusting for differences in the patients’ characteristics between the two modalities. Notably, the most common cause of death was infection in this Korean cohort.

Early Nephrology Referral Reduces the Economic Costs among Patients Who Start Renal Replacement Therapy: A Prospective Cohort Study in Korea

Background The nature of cost-saving effects of early referral to a nephrologist in patients with chronic kidney disease (CKD) is not fully evaluated. We evaluated the health care costs before and after dialysis according to the referral time. Methods A total of 879 patients who were newly diagnosed as having end-stage renal disease from August 2008 to June 2011 were prospectively enrolled. The early referral (ER) group was defined as patients who were referred to a nephrologist more than a year before dialysis and had visited a nephrology clinic 2 or more times. Patients whose referral time was less than a year were considered the late referral (LR) group. Information about medical costs was acquired from the claim data of the Korea Health Insurance Review and Assessment Service. Results The total medical costs during the first 12 months after the initiation of dialysis were not different between the 526 ER patients and the 353 LR patients. However, the costs of the ER patients during the first month were significantly lower than those of the LR patients (ER vs. LR: 3029±2219 vs. 3438±2821 US dollars [USD], P = 0.025). The total 12-month health care costs before the initiation of dialysis were significantly lower in the ER group (ER vs. LR: 6206±5873 vs. 8610±7820 USD, P<0.001). In the multivariate analysis, ER significantly lowered the health care costs during the 12 months before (2534.0±436.2 USD, P<0.001) and the first month (428.5±172.3 USD, P = 0.013) after the initiation of dialysis. Conclusions The ER of patients with CKD to a nephrologist is associated with decreased medical costs during the pretreatment period of renal replacement therapy and the early period of dialysis initiation.

Differential Effect of Viral Hepatitis Infection on Mortality among Korean Maintenance Dialysis Patients: A Prospective Multicenter Cohort Study

The role of infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) in terms of survival among dialysis patients remains incompletely understood. In the present multicenter prospective cohort study, we investigated the prevalences of HBV and HCV infection among 3,321 patients receiving maintenance dialysis in Korea, and assessed the impacts of these infections on survival. All included patients underwent hepatitis B antigen (HBsAg) and HCV antibody (Ab) testing, which revealed that 236 patients (7.1%) were HBsAg-positive, and 123 patients (3.7%) were HCV Ab-positive. HBsAg-positive and HCV Ab-positive patients were matched to hepatitis virus-negative patients using a propensity score at a ratio of 1:2. The prevalences of HBV and HCV infection did not significantly differ according to dialysis modality. Linear-by-linear association analysis revealed that hepatitis B prevalence significantly increased with increasing dialysis vintage (p = 0.001), and hepatitis C prevalence tended to be higher with increasing dialysis vintage (p = 0.074). We compared the survival of HBsAg-positive and HCV Ab-positive patients to that of hepatitis virus-negative patients. After propensity score matching, cumulative survival did not differ between HBsAg-positive and HBsAg-negative patients (p = 0.37), while HCV Ab-positive patients showed significantly lower survival than HCV Ab-negative patients (p = 0.03). The main conclusions of the present study are that HBV infection prevalence increased with longer dialysis vintage, and that both HBV and HCV infections were most prevalent among patients with the longest dialysis vintage. Additionally, HCV infection among maintenance dialysis patients is associated with an increased risk of mortality.

Nafamostat Mesilate as an Anticoagulant During Continuous Renal Replacement Therapy in Patients With High Bleeding Risk: A Randomized Clinical Trial.

AbstractNafamostat mesilate (NM), a synthetic serine protease inhibitor, has been used increasingly as an anticoagulant during continuous renal replacement therapy (CRRT). However, there, are limited data from randomized studies on NM use in patients with a bleeding tendency. This prospective study evaluated the efficacy and safety of NM use during CRRT in patients with acute kidney injury (AKI) patients at high risk of bleeding.Patients with AKI at high risk of bleeding were randomized into the NM and no anticoagulant (NA) groups. The primary outcome was the treatment efficacy represented by the filter lifespan. Several parameters, including safety and patient survival rates at 30 and 90 days, were analyzed as secondary outcomes.Fifty-five patients were included in this study (NM group = 31, NA group = 24). The baseline characteristics did not significantly differ between the groups. The mean filter lifespan was significantly longer in the NM group than in the NA group (31.7 ± 24.1 versus 19.5 ± 14.9 hours; P = 0.035). The most common cause of filter failure was filter clotting, which was significantly more frequent in the NA group than in the NM group (59.6% versus 37.7%, P = 0.024). The Cox proportional hazards model showed a 42.2% longer filter lifespan in the NM group compared with the NA group (hazard ratio, 0.578; 95% confidence interval, 0.362–0.923; P = 0.022). There were no significant differences in the frequencies of transfusions and major bleeding between the groups. Patient survival rates at 30 and 90 days after CRRT initiation were comparable between the groups.Nafamostat mesilate is a safe and effective anticoagulant for CRRT and allows sufficient filter survival without increasing the risk of bleeding in critically ill patients with AKI and bleeding tendencies.

Free Thyroxine Level as an Independent Predictor of Infection-Related Mortality in Patients on Peritoneal Dialysis: A Prospective Multicenter Cohort Study

Background Previous studies have reported the relationship between thyroid hormone levels and mortality in dialysis patients. However, little is known about the association of free thyroxine (fT4) and mortality in patients on peritoneal dialysis (PD). This study investigated the association between basal and annual variation in fT4 level and mortality in PD patients. Methods Patients on maintenance PD were enrolled from a prospective multicenter cohort study in Korea; their serum triiodothyronine, fT4, and thyroid-stimulating hormone levels were measured 12 months apart. Patients with overt thyroid disease and those receiving thyroid hormone replacement therapy were excluded from the analysis. Patients were divided into two groups based on the median levels of fT4. The differences of all-cause, infection-related, and cardiovascular mortalities were analyzed between the two groups. The association of basal levels and annual variation with mortality was investigated with Kaplan–Meier curves and Cox proportional hazard models. Results Among 235 PD patients, 31 (13.2%) deaths occurred during the mean follow-up period of 24 months. Infection (38.7%) was the most common cause of death. Lower basal fT4 levels were an independent predictor of all-cause and infection-related death (hazard ratio [HR] = 2.74, 95% confidence interval [CI] 1.27–5.90, P = 0.01, and HR = 6.33, 95% CI 1.16–34.64, P = 0.03, respectively). Longitudinally, patients with persistently lower fT4 levels during the 12-month period had significantly higher all-cause mortality than those with persistently higher levels (HR = 3.30, 95% CI 1.15–9.41, P = 0.03). The area under the receiver operating characteristic curve of fT4 for predicting all-cause and infection-related mortality was 0.60 and 0.68, respectively. Conclusions fT4 level is an independent predictor of mortality and is especially attributable to infection in PD patients. This predictor was consistent when considering both baseline measurements and annual variation patterns. Close attention to infection in PD patients with relatively lower fT4 levels should be considered.

Depressive Symptoms, Patient Satisfaction, and Quality of Life Over Time in Automated and Continuous Ambulatory Peritoneal Dialysis Patients: A Prospective Multicenter Propensity-Matched Study

AbstractHealth-related quality of life (HRQOL) is an important clinical outcome for dialysis patients. However, relative superiority in HRQOL between automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD) are not clearly known. We compared HRQOL over time between APD and CAPD patients and evaluated factors associated with HRQOL.All 260 incident patients initiating APD or CAPD at multiple centers throughout Korea were prospectively enrolled in this study between October 2010 and February 2013. HRQOL, depressive symptoms, and renal treatment satisfaction were assessed 1 and 12 months after the start of dialysis by the Kidney Disease Quality of Life Short Form 36 (KDQOL-36), the Beck Depression Inventory (BDI), and the Renal Treatment Satisfaction Questionnaire (RTSQ), respectively.Of 196 patients who completed all questionnaires and did not change the peritoneal dialysis (PD) modality during the 1-year follow-up period, 160 were matched. APD patients showed better baseline HRQOL than CAPD patients for the symptoms, patient satisfaction, pain, and social function domains. There were no differences in HRQOL between the 2 groups at 12 months, and CAPD patients had significantly greater improvements in symptoms (P = 0.02), the mental composite summary (P = 0.03), and health status domains (P = 0.03) than APD patients. There were similar improvements in depressive symptoms (P = 0.01) and patient satisfaction with treatment (P = 0.01) in CAPD and APD patients. Interestingly, depressive symptoms, not PD modality, was the most influential and consistent factor for HRQOL. Despite the spontaneous improvement of depressive symptoms, considerable PD patients still had depressive symptoms at the 1-year appointment.APD has no advantage over CAPD for HRQOL. Considering the substantial negative effect of depressive symptoms on HRQOL, it is important to evaluate PD patients for depression and to treat those with depression to improve their HRQOL.

The Korean Clinical Research Center for End-Stage Renal Disease Study Validates the Association of Hemoglobin and Erythropoiesis-Stimulating Agent Dose with Mortality in Hemodialysis Patients

Background Anemia is an important risk factor for mortality in hemodialysis (HD) patients. However, higher hemoglobin (Hb) is not necessarily better, as seen in several studies. This study aimed to validate the clinical use of an Hb target of 10–11 g/dL in Korean HD patients. Methods A total of 1,276 HD patients from the Clinical Research Center (CRC) for End-Stage Renal Disease (ESRD) were investigated in a prospective observational study. Cox proportional hazard analysis was conducted for each category of time-dependent Hb level and erythropoiesis-stimulating agent (ESA) dose, with subgroup analysis stratified by age and diabetes status. Results Using a reference Hb level of 10–11 g/dL, the hazard ratios (HRs) of death were 5.12 (95% confidence interval [CI], 2.62–10.02, P <0.05) for Hb level <9.0 g/dL, and 2.03 (CI, 1.16–3.69, P <0.05) for Hb level 9.0–10.0 g/dL, after adjustment for multiple clinical variables. However, an Hb level ≥11 g/dL was not associated with decreased mortality risk. In an adjusted model categorized by Hb and ESA dose, the risk of death at an Hb level <10 g/dL and a higher dose of ESA (≥126 U/kg/week) had an HR of 2.25 (CI, 1.03–4.92, P <0.05), as compared to Hb level 10–11 g/dL and a lower dose of ESA. In subgroup analysis, those older than 65 years or who were diabetic had greater risk for mortality only in Hb category <9.0 g/dL. However, there was no significant interaction between age or diabetes status and Hb. Conclusion Using CRC-ESRD data, we validated the association between Hb and ESA dose and mortality in Korean HD patients. The clinical practice target of an Hb of 10–11 g/dL before the new KDIGO guideline era seems reasonable considering its survival benefit in HD patients.

Individualized prediction of mortality using multiple inflammatory markers in patients on dialysis

This study aimed to evaluate whether the combination of inflammatory markers could provide predictive powers for mortality in individual patients on dialysis and develop a predictive model for mortality according to dialysis modality. Data for inflammatory markers were obtained at the time of enrollment from 3,309 patients on dialysis from a prospective multicenter cohort. Net reclassification index (NRI) and integrated discrimination improvement (IDI) were calculated. Cox proportional hazards regression analysis was used to derive a prediction model of mortality and the integrated area under the curve (iAUC) was calculated to compare the predictive accuracy of the models. The incremental additions of albumin, high-sensitive C-reactive protein (hsCRP), white blood count (WBC), and ferritin to the conventional risk factors showed the highest predictive powers for all-cause mortality in the entire population (NRI, 21.0; IDI, 0.045) and patients on peritoneal dialysis (NRI, 25.7; IDI, 0.061). The addition of albumin and hsCRP to the conventional risk factors markedly increased predictive powers for all-cause mortality in HD patients (NRI, 19.0; IDI, 0.035). The prediction model for all-cause mortality using conventional risk factors and combination of inflammatory markers with highest NRI value (iAUC, 0.741; 95% CI, 0.722–0.761) was the most accurate in the entire population compared with a model including conventional risk factors alone (iAUC, 0.719; 95% CI, 0.700–0.738) or model including only significant conventional risk factors and inflammatory markers (iAUC, 0.734; 95% CI, 0.714–0.754). Using multiple inflammatory markers practically available in a clinic can provide higher predictive power for all-cause mortality in patients on dialysis. The predictive model for mortality based on combinations of inflammatory markers enables a stratified risk assessment. However, the optimal combination for the predictive model was different in each dialysis modality.

Survival predictors in anuric patients on peritoneal dialysis: A prospective, multicenter, propensity score-matched cohort study

Prevalent anuric peritoneal dialysis (PD) patients usually have higher mortality than PD patients with residual urine volume. We aimed to evaluate the predictors of survival in anuric PD patients. Anuric PD patients (n = 505, <100 mL of daily urine) enrolled in Korean nationwide prospective cohort were analyzed. Survived and non-survived anuric PD patients were compared by propensity score matching analysis with a ratio of two to one. The propensity method was used to adjust for patient age, dialysis duration, and presence of diabetes. Among the total anuric PD patients, non-survived patients showed a significantly older age, higher incidence of diabetes, coronary artery disease, and arrhythmia, and lower serum creatinine and albumin. After propensity score matching, multivariate Cox regression analysis for patient survival showed a decreasing risk as serum albumin increased (HR = 0.347, p = 0.0094). Analysis using the receiver-operating-characteristic (ROC) curve showed that survival could be predicted with a sensitivity of 59.4% and a specificity of 63.2% using a cutoff value of 3.6 g/dL of serum albumin in unmatched total PD patients. The beneficial impact of high albumin level on death was significantly greater for patients with older age (≥50 years), no diabetes, low ultrafiltration (UF) volume (<1000 mL/day), and low levels of serum creatinine (<10 mg/dL), total cholesterol (<177.5 mg/dL), ferritin (<100 ng/mL), and high-sensitivity C-reactive protein (hs-CRP) (<0.1 mg/dL). Survival in anuric PD patients was associated with age, comorbidities, and nutritional factors such as creatinine and albumin. After adjustment by propensity score matching, serum albumin level was an independent predictor for survival in anuric PD patients.

Survival in patients on hemodialysis: Effect of gender according to body mass index and creatinine

Background The association of a higher body mass index (BMI) with better survival is a well-known “obesity paradox” in patients on hemodialysis (HD). However, men and women have different body compositions, which could impact the effect of BMI on mortality. We investigated the effect of gender on the obesity-mortality relationship in Korean patients on HD. Methods This study included 2,833 maintenance patients on HD from a multicenter prospective cohort study in Korea (NCT00931970). The relationship between categorized BMI and gender-specific mortality was evaluated by an adjusted Cox proportional hazard model with restricted cubic spline analyses and the Competing risk analysis. We also investigated the effect of changes in BMI over 12 months and serum creatinine level on survival in male and female patients on HD. Results The mean BMI was 22.6 ± 3.3 kg/m2 and the mean follow up duration was 24.2 ± 3.4 months. The patients with the highest quintile of BMI (≥25.1 kg/m2) showed lower mortality (subdistributional hazard ratio [SHR] = 0.63, 95% confidence interval [CI] = 0.43–0.93, P = 0.019) compared with those with the reference BMI quintile. When analyzed by gender, male patients with a BMI over 25.1 kg/m2 had lower mortality risk (HR = 0.43, 95% CI = 0.25–0.75, P = 0.003); however, no significant difference was found in female patients. Increased BMI after 12 months and high serum creatinine were associated with better survival only in male patients on HD. Conclusions BMI could be used as a risk factor for mortality in male patients on HD. However, the mortality of female patients on HD was not related with baseline and follow-up BMI. This suggests that BMI is a good surrogate marker of lean body composition, especially in male patients on HD.