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INTRODUCTION Arteriovenous fistula (AVF) is historically known to be the ideal option for vascular access (VA) for hemodialysis compared with arteriovenous graft (AVG). However, this approach has been recently questioned in the aging population because of their poor vessel quality and multiple comorbidities. METHODS Data from a total of 2200 patients from the VA category of The Catholic Medical Center nephrology registry from March 2009 to February 2017 were analyzed. We compared VA patency and patient survival between two groups, AVF and AVG, according to age. FINDINGS Compared with the AVG group, survival benefit in the AVF group continued even in patients ≥80 years. In the whole population, all the primary patency (PP), primary-assisted patency (PAP), and secondary patency (SP) measures were superior in the AVF group. With regard to subgroups, PP was comparable between the two groups in patients ≥65 years, whereas PAP and SP were superior in the AVF group even in septuagenarian patients who are from 70 to 79 years old. In patients ≥80 years, all the patency measures were comparable between the two groups. When the separate comparison of lower-arm AVF (or upper-arm AVF) and AVG, lower-arm AVF failed to demonstrate its superiority in any kind of patency in septuagenarian patients compared with AVG, whereas upper-arm AVF demonstrated its superiority in PAP and SP in septuagenarian patients. However, even upper-arm AVF failed to demonstrate its superiority in any kind of patency in patients ≥80 years. DISCUSSION Arteriovenous fistula if using upper-arm vessel showed the superior VA patency up to septuagenarian patients, whereas, in HD patients ≥80 years, AVF and AVG were comparable in VA patency.

According to the Korean ESKD registry (1), in 2018 there were 17,621 incident ESKD patients in Korea. The unadjusted incidence rate was 340.0 per million population (PMP) (Table 1). The number of patients with incident ESKD continued to increase until 2006, plateaued between 2007 and 2009, and rose again from 2010 (Figure 1A). This trend in rising ESKD incidence rate implies increasing burden of CKD, which is attributable to the aging Korean population and high rate of diabetes mellitus (DM) and hypertension. View this table: Table 1. Trends in annual number of patients with incident ESKD and incidence rates of ESKD in the Korean population, 2000–2018 Figure 1. Trends in the annual number of patients (A) with incident ESKD or (B) with prevalent ESKD by modality in the Korean population, 2000-2018. The number of patients with incident and prevalent HD has steadily increased. The number of patients with incident and prevalent PD continuously declined since 2006. The number of kidney transplants has gradually increased and plateaued since 2016. On December 31, 2018, there were 103,984 patients with prevalent ESKD in Korea, representing a 271% increase since 2000. The unadjusted prevalence rate was 2006.4 PMP (Table 1), which ranked high globally (2). Prevalence rate of ESKD has steadily increased year after year (Figure 1B). Hemodialysis (HD) was the predominant form of ESKD treatment modality in all years in both patients with incident and prevalent ESKD. The number of patients with incident peritoneal dialysis (PD) rapidly increased from the late 1990s and peaked in 2006 ( n =2568), then declined every year until 2018 ( n =735, a decrease of 71%) (Figure1A, Table 1). The ratio of HD to PD gradually changed from 68.9:31.1 in 2006 to 95.3:4.7 in 2018 in patients with incident ESKD, and from 78.4:21.6 in 2006 to 92.5:7.5 in 2018 in patients with prevalent ESKD …

Background Many studies have evaluated the usefulness of creatinine- (eGFRcr) and cystatin C-based estimated glomerular filtration rate (eGFRcys) at specific time points in predicting renal outcome. This study compared the performance of both eGFR changing slopes in identifying patients at high risk of end-stage renal disease (ESRD). Methods From 2012 to 2017, patients with more than three simultaneous measurements of serum creatinine and cystatin C for 1 year were identified. Rapid progression was defined as eGFR slope

Introduction: Previous studies have revealed that vascular access resistance is constant during hemodialysis, but differs according to vascular access type. It is possible that intra-access flow volume (Qac) variation during hemodialysis may also differ according to vascular access type. We conducted this study to investigate whether there are differences in Qac according to vascular access type during hemodialysis. Methods: A total of 58 lower-arm arteriovenous fistula, 14 lower-arm arteriovenous graft, 27 upper-arm arteriovenous fistula, and 45 upper-arm arteriovenous graft cases were studied. Three consecutive Qac values (at 30, 120, and 240 min after the start of hemodialysis) were measured in each patient by the ultrasound dilution technique. Variations in Qac over time were analyzed using repeated measures analysis of variance and multivariate regression analyses, to assess the impact of different factors on Qac variation. Results: The repeated measures analysis of variance revealed that a significant interaction exists between time and vascular access type (p Conclusion: This study showed that there is a significant difference in Qac variation according to vascular access type during hemodialysis and that arteriovenous graft (vs arteriovenous fistula) and the lower-arm location (vs upper arm) were associated with a decrease in Qac during hemodialysis. This suggests that consideration of vascular access type is required to minimize Qac variation during hemodialysis.

Background : Unlike patterns observed in the general population, obesity is associated with better survival among hemodialysis patients, which could be explained by reverse causation or illness-related weight loss. However, the time-varying effect of body mass index (BMI) on hemodialysis survival has not been investigated. Therefore, this study investigated the time-varying effect of BMI on mortality after starting hemodialysis. Methods : In the present study, we examined Korean Society of Nephrology data from 16,069 adult patients who started hemodialysis during or after the year 2000. Complete survival data were obtained from Statistics Korea. Survival analysis was performed using Cox regression and a non-proportional hazard fractional polynomial model. Results : During the median follow-up of 8.6 years, 9,272 patients (57.7%) died. Compared to individuals with normal BMI (18.5-24.9 kg/m2), the underweight group (< 18.5 kg/m2) had a higer mortality hazard ratio (HR, 1.292; 95% confidence interval [CI], 1.203-1.387; P < 0.001) and the overweight group (25.0-29.9 kg/m2) had a lower mortality HR (0.904; 95% CI, 0.829-0.985; P = 0.022). The underweight group had increasing HRs during the first 3 to 7 years after starting hemodialysis, which varied according to age group. The young obese group (< 40 years old) had a U-shaped temporal trend in their mortality HRs, which reflected increased mortality after 7 years. Conclusion : The obese hemodialysis group had better survival during the early post-dialysis period, although the beneficial effect of obesity disappeared 7 years after starting hemodialysis. The young obese group also had an increased mortality HR after 7 years.

Background:Many studies have compared patient survival outcome between hemodialysis (HD) and peritoneal dialysis (PD); however, time-varying risks of dialysis modality have been rarely investigated. This study aimed to investigate dialysis modality switch and its association with the survival outcome in the Korean population.Methods:Data from the Korean Society of Nephrology were used. A total of 21,840 incident dialysis patients who started dialysis in or after 2000 were analyzed. For the survival analysis, both proportional and non-proportional hazard assumptions were applied. For the modality switch, time-varying covariate Cox regression was applied.Results:During the median follow-up of 8 years, PD group showed increased adjusted hazard ratio (HR) of 1.248 (95% CI 1.071–1.454, p = 0.004) for mortality. Interaction of PD status with female sex was significant with an HR of 1.080 (95% CI 1.000–1.165, p = 0.050). Dialysis modality switch was associated with increased HR of 1.094 (95% CI 1.015–1.180, p = 0.019), albeit switch from PD to HD did not show significant HR until 6 years. Interestingly, time-varying risk analysis showed a decreased HR of PD after 10 years in the non-switcher group, which was consistent in patients with high traditional risk factors (with diabetes, elderly).Conclusions:PD was associated with increased HR of mortality in the first 8 years, then it was associated with decreased HR of mortality after 10 years. Dialysis modality switch was associated with increased mortality risk, but switch from PD to HD within 6 years did not show significant hazard of mortality.

Background: We investigated the associations between mineral metabolism parameters and mortality to identify optimal targets in Korean hemodialysis patients. Methods: Among hemodialysis patients registered in the end-stage renal disease registry of the Korean Society of Nephrology between March 2012 and June 2017, those with serum calcium, phosphorus, and intact parathyroid hormone (iPTH) measured at enrollment were included. Association of serum levels of calcium, phosphorus, and iPTH with all-cause mortality was analyzed. Results: Among 21,433 enrolled patients, 3,135 (14.6%) died during 24.8 ± 14.5 months of follow-up. After multivariable adjustment, patients in the first quintile of corrected calcium were associated with lower mortality (hazard ratio [HR], 0.84; 95% confidence interval [95% CI], 0.71-0.99; P = 0.003), while those in the fifth quintile were associated with higher mortality (HR, 1.39; 95% CI, 1.20-1.61; P⟨ 0.001) compared with those in the third quintile. For phosphorus, only the lowest quintile was significantly associated with increased mortality (HR, 1.24; 95% CI, 1.08-1.43; P = 0.003). The lowest (HR, 1.18; 95% CI, 1.02-1.36; P = 0.026) and highest quintiles of iPTH (HR, 1.24; 95% CI, 1.05-1.46; P = 0.013) were associated with increased mortality. For target counts achieved according to the Kidney Disease Outcomes Quality Initiative guideline, patients who did not achieve any mineral parameter targets hadhigher mortality than those who achieved all three targets (HR, 1.37; 95% CI, 1.12-1.67; P = 0.003). Conclusion: In Korean hemodialysis patients, high serum calcium, low phosphorus, and high and low iPTH levels were associated with increased all-cause mortality.

Purpose Sevelamer, a noncalcium phosphate binder, has been shown to attenuate the progression of vascular calcification and improve survival in patients with chronic kidney disease undergoing dialysis compared with calcium-based binders. Using real-world data from a cohort study and the Health Insurance Review and Assessment Service database, we conducted a cost-effectiveness analysis comparing sevelamer with calcium acetate in dialysis patients from the perspective of the National Health Insurance Service in South Korea. Methods Data (demographic, diagnostic, laboratory, and survival) from 4674 patients undergoing dialysis enrolled in a multicenter prospective cohort study conducted in South Korea between September 2008 and December 2012 were linked to phosphate binder use, hospitalization, and cost data available from the Health Insurance Review and Assessment Service database. After propensity score matching, a dataset comprising comparable patients treated with either sevelamer (n = 501) or calcium acetate (n = 501) was used in the cost-effectiveness analysis. A Markov model was used to estimate costs, life years, quality-adjusted life years (QALYs), and cost-effectiveness over each patient’s lifetime. Forty-month treatment-specific overall survival (OS) data available from the dataset were extrapolated to lifetime survival with the use of regression analysis. Findings Patients had a mean age of 56.3 years and were treated with dialysis for a mean duration of 67.6 months. Compared with calcium acetate, sevelamer was associated with an incremental cost of South Korean Won (₩) 12,246,911 ($10,819) and a gain of 1.758 life years and 1.108 QALYs per patient. This outcome yielded incremental cost-effectiveness ratios of ₩6,966,350 ($6154) and ₩11,057,699 ($9768) per life year and QALY gained, respectively. Conclusions regarding sevelamer’s cost-effectiveness were insensitive to alternative assumptions in time horizon, discount rate, hospitalization rate, costs, and health utility estimates, and they remained consistent in 100% of the model iterations, considering a willingness-to-pay threshold of ₩31,894,720 ($28,176) per QALY gained. Implications This analysis of real-world data found that sevelamer’s higher cost relative to calcium acetate was adequately offset by improved survival among patients undergoing dialysis in South Korea. As such, sevelamer offers good value for money, representing a cost-effective alternative to calcium-based binders.

Background It is thought that hyperuricemia might lower the risk of mortality among hemodialysis patients, unlike in the general population, but the evidence is controversial. The aim of the current study was to evaluate the impact of serum uric acid level on the long-term clinical outcomes of hemodialysis patients in Korea. Methods Retrospective analysis was performed on data from the End-Stage Renal Disease Registry of the Korean Society of Nephrology. This included data for 7,333 patients (mean age, 61 ± 14 years; 61% male) who received hemodialysis from January 2001 through April 2015. Initial laboratory data were used in the analysis. Results The mean serum uric acid level in this study was 7.1 ± 1.7 mg/dL. Body mass index, normalized protein catabolic rate, albumin, and cholesterol were positively correlated with serum uric acid level after controlling for age and sex. After controlling for demographic data, comorbidities, and residual renal function, a higher uric acid level was independently associated with a significantly lower all-cause mortality (hazard ratio [HR], 0.90 per 1 mg/dL increase in uric acid level; 95% confidence interval [CI], 0.83-0.97; P = 0.008), but not cardiovascular mortality (HR, 0.90; 95% CI, 0.80-1.01; P = 0.078). Comparing uric acid levels in the highest and lowest quintiles, the HR for all-cause mortality was 0.65 (95% CI, 0.42-0.99; P = 0.046). Conclusion Hyperuricemia was strongly associated with a lower risk of all-cause mortality, but there seems to be no significant association between serum uric acid level and cardiovascular mortality among Korean hemodialysis patients with end-stage renal disease.

Supplementary_Material_915024 for Changes in mortality hazard of the Korean long-term dialysis population: The dependencies of time and modality switch by Jong Cheol Jeong, Sejoong Kim, Ki Pyo Kim, Yongjin Yi, Shin Young Ahn, Dong-Chan Jin, Ho Jun Chin, Dong-Wan Chae and Ki Young Na in Peritoneal Dialysis International

BACKGROUND: Tacrolimus is used as a steroid-sparing immunosuppressant in adults with minimal change nephrotic syndrome. However, combined treatment with tacrolimus and low-dose steroid has not been compared with high-dose steroid for induction of clinical remission in a large-scale randomized study. METHODS: In this 24-week open-label noninferiority study, we randomized 144 adults with minimal change nephrotic syndrome to receive 0.05 mg/kg twice-daily tacrolimus plus once-daily 0.5 mg/kg prednisolone, or once-daily 1 mg/kg prednisolone alone, for up to 8 weeks or until achieving complete remission. Two weeks after complete remission, we tapered the steroid to a maintenance dose of 5–7.5 mg/d in both groups until 24 weeks after study drug initiation. The primary end point was complete remission within 8 weeks (urine protein: creatinine ratio 3.0 g/g) after complete remission to within 24 weeks of study drug initiation. RESULTS: Complete remission within 8 weeks occurred in 53 of 67 patients (79.1%) receiving tacrolimus and low-dose steroid and 53 of 69 patients (76.8%) receiving high-dose steroid; this difference demonstrated noninferiority, with an upper confidence limit below the predefined threshold (20%) in both intent-to-treat (11.6%) and per-protocol (17.0%) analyses. Groups did not significantly differ in time until remission. Significantly fewer patients relapsed on maintenance tacrolimus (3–8 ng/ml) plus tapered steroid versus tapered steroid alone (5.7% versus 22.6%, respectively; P=0.01). There were no clinically relevant safety differences. CONCLUSIONS: Combined tacrolimus and low-dose steroid was noninferior to high-dose steroid for complete remission induction in adults with minimal change nephrotic syndrome. Relapse rates were significantly lower with maintenance tacrolimus and steroid compared with steroid alone. No clinically-relevant differences in safety findings were observed.

The prevalence rate and the incidence rate of hemodialysis and functioning kidney transplant recipients have continuously increased; on the contrary, those of peritoneal dialysis have continuously decreased since 2006. Dialysis patients have been getting older and have been maintained on dialysis longer. Diabetic nephropathy was the leading cause of end stage renal disease. The type of hemodialysis vascular access has been stable during the last 5 years (arteriovenous fistulas 76%, arteriovenous grafts 16%, central venous catheters 8% at 2016). Peritoneal dialysis catheter was mostly inserted surgically (67%), and swan neck straight tip peritoneal dialysis catheter was the most commonly used (48%). Vascular access was managed by radiologists and surgeons, and the management was fragmented among them in the past. However, since the nephrologists became interested in and knowledgeable about the vascular access, they began to play roles in vascular access management. Vascular access has been mostly created by vascular surgeons (≈60%); tunneled central venous hemodialysis catheter insertion and endovascular intervention such as percutaneous transluminal angioplasty (PTA) and thrombectomy have been mostly performed by radiologists (≈70%). Tunneled hemodialysis catheter insertion and endovascular intervention by nephrologists have slowly but consistently increased. Recently, the number of central venous hemodialysis catheter insertion has decreased, and tunneled hemodialysis catheter has been inserted more than non-tunneled hemodialysis catheter, indicating that vascular access has been created timely and the vascular access team has been educated about and following international guidelines.

Background/Aims The optimal serum bicarbonate level is controversial for patients who are undergoing hemodialysis (HD). In this study, we analyzed the impact of serum bicarbonate levels on mortality among HD patients. Methods Prevalent HD patients were selected from the Clinical Research Center registry for End Stage Renal Disease cohort in Korea. Patients were categorized into quartiles according to their total carbon dioxide (tCO2) levels: quartile 1, a tCO2 of < 19.4 mEq/L; quartile 2, a tCO2 of 19.4 to 21.5 mEq/L; quartile 3, a tCO2 of 21.6 to 23.9 mEq/L; and quartile 4, a tCO2 of ≥ 24 mEq/L. Cox regression analysis was used to calculate the adjusted hazard ratio (HR) and confidence interval (CI) for mortality. Results We included 1,159 prevalent HD patients, with a median follow-up period of 37 months. Kaplan-Meier analysis revealed that the all-cause mortality was significantly higher in patients from quartile 4, compared to those from the other quartiles (p = 0.009, log-rank test). The multivariate Cox proportional hazard model revealed that patients from quartile 4 had significantly higher risk of mortality than those from quartile 1, 2 and 3, after adjusting for the clinical variables in model 1 (HR, 1.99; 95% CI, 1.15 to 3.45; p = 0.01) and model 2 (HR, 1.82; 95% CI, 1.03 to 3.22; p = 0.04). Conclusions Our data indicate that high serum bicarbonate levels (a tCO2 of ≥ 24 mEq/L) were associated with increased mortality among prevalent HD patients. Further effort might be necessary in finding the cause and correcting metabolic alkalosis in the chronic HD patients with high serum bicarbonate levels.

Background/Aims Inadequacy of dialysis is associated with morbidity and mortality in chronic hemodialysis (HD) patients. Blood flow rate (BFR) during HD is one of the important determinants of increasing dialysis dose. However, the optimal BFR is unclear. In this study, we investigated the impact of the BFR on all-cause mortality in chronic HD patients. Methods Prevalent HD patients were selected from Clinical Research Center registry for end-stage renal disease cohort in Korea. We categorized patients into two groups by BFR < 250 and ≥ 250 mL/min according to the median value of BFR 250 mL/min in this study. The primary outcome was all-cause mortality. Results A total of 1,129 prevalent HD patients were included. The number of patients in the BFR < 250 mL/min was 271 (24%) and in the BFR ≥ 250 mL/min was 858 (76%). The median follow-up period was 30 months. Kaplan-Meier analysis showed that the mortality rate was significantly higher in patients with BFR < 250 mL/min than those with BFR ≥ 250 mL/min (p = 0.042, log-rank). In the multivariate Cox regression analyses, patients with BFR < 250 mL/min had higher all-cause mortality than those with BFR ≥ 250 mL/min (hazard ratio, 1.66; 95% confidence interval, 1.00 to 2.73; p = 0.048). Conclusions Our data showed that BFR < 250 mL/min during HD was associated with higher all-cause mortality in chronic HD patients.

Introduction To increase the rate of arteriovenous fistula (AVF) use, assisted procedures for immature AVF have been strenuously performed. However, this is controversial in that an AVF matured by these assisted procedures may require more frequent intervention to maintain its patency, and have decreased long-term patency. Methods Eighty four AVFs that were matured with assisted maturation procedures and 266 AVFs that matured spontaneously without intervention, created between November 2009 and March 2013 from the hemodialysis (HD) vascular access (VA) cohort, were compared retrospectively and we also investigated the factors that may influence AVF long-term patency. Median follow-up was 26.8 months (interquartile range, 6.6–45.0 months). Findings Access survival did not differ between AVFs matured by assisted procedures and spontaneously mature AVFs (P = 0.29). In multivariate Cox regression analysis of AVF survival, age (HR, 1.029; 95% CI, 1.004–1.056; P = 0.024), maturation without assisted procedures 4–6 weeks after AVF creation (HR, 0.233; 95% CI, 0.107–0.506; P

Gabapentin is commonly used for controlling convulsions, restless pain syndrome, and pain in diabetic neuropathy. Common side effects include dizziness, somnolence, ataxia, peripheral edema, and confusion; gabapentin-induced rhabdomyolysis is rarely reported. To date, the reported cases of gabapentin-induced rhabdomyolysis have been associated with patients with multiple underlying diseases and assuming multiple medicines for various reasons. In this report, we describe a case of gabapentin-induced rhabdomyolysis in a 32-year-old woman with no medical history. We also review related literature and discuss the possible mechanism and the association with other factors. This case shows that gabapentin can induce rhabdomyolysis in healthy patients and that clinicians must consider the possible association between gabapentin and rhabdomyolysis.

Background: Uremic pruritus is a common, but unpleasant, complication of end-stage renal disease. The uremic burden may differ between hemodialysis (HD) and peritoneal dialysis (PD) patients. This difference may also change the clinical characteristics of uremic pruritus between the 2 modalities. In this study, we investigated the uremic pruritus between patients on HD and PD. Methods: A total of 425 HD and 223 PD patients from the Clinical Research Center registry in Korea were included. Patients were assessed for pruritus intensity, scratching activity, pruritus distribution, and frequency of pruritus-related sleep disturbance using the visual analog scale and questionnaire. Results: The prevalence of uremic pruritus was higher in PD patients than that in HD patients (62.6% vs. 48.3%, P = 0.001). In the multivariable logistic analysis, PD treatment was significantly associated with the prevalence of uremic pruritus (odds ratio, 1.76; 95% confidence interval, 1.20-2.57, P = 0.004) after adjustment for clinical variables. The visual analog scale score, representing a subjective intensity of itchiness, was significantly higher in PD patients (PD 2.11 +/- 2.32 vs. HD 1.65 +/- 2.28, P = 0.013) compared with HD patients. The intensity of uremic pruritus was independently related with serum albumin levels (beta = -0.143, P = 0.006) in HD patients and total weekly Kt/V (beta = -0.176, P = 0.028) in PD patients. Conclusion: Our data demonstrate the difference in prevalence, intensity, and risk factors of uremic pruritus between HD and PD patients. These findings suggest that careful consideration for uremic pruritus might be needed in end-stage renal disease patients according to the dialysis modality. Copyright (C) 2016. The Korean Society of Nephrology. Published by Elsevier.

Purpose: The exchange from a non-tunneled hemodialysis catheter to a tunneled one over a guidewire using a previous venotomy has been reported to be safe. However, some concerns that it may increase infection risk prevent its clinical application. This approach seems particularly useful for acute kidney injury patients requiring initial renal replacement therapy, in whom we frequently worry about the choice of non-tunneled versus tunneled catheters. Materials and methods: From March 2012 to February 2016, 88 cases to receive the over-the-guidewire exchange method from a non-tunneled to a tunneled catheter and 521 cases to receive de novo tunneled catheter placement from the hemodialysis vascular access cohort were compared retrospectively. Results: The immediate complication, later catheter dysfunction requiring replacement, and infection rates were comparable between the two groups. Newly placed tunneled catheter survival in the over-the-guidewire exchange group was comparable with survival in the de novo tunneled catheter group (p = 0.24). In addition, when we compared the same two methods among only intensive care unit patients; they remained similar (p = 0.19). Conclusion: An exchange with the over-the-guidewire method from a non-tunneled to a tunneled catheter was comparable to a de novo catheter placement technique. Therefore, this method should be viewed more favorably and should especially be considered for acute kidney injury patients.

Background: Poor vessel quality and limited life expectancy in the elderly may make arteriovenous fistula (AVF) less ideal than arteriovenous graft (AVG) or catheter for vascular access (VA) in hemodialysis (HD). Methods: A total of 946 adult incident HD patients from clinical research center registry for end-stage renal disease prospective cohort in South Korea were analyzed for outcomes with AVF and AVG. Results: Overall, AVF was associated with better patient survival only in male (p < 0.001) and diabetic (p = 0.004) patients, although it was superior to AVG in access patency, regardless of diabetes mellitus status and gender. AVG (vs. AVF; hazard ratio (HR) 2.282; 95% CI 1.071-4.861; p = 0.032) was associated with poor patient survival. In elderly patients (≥65 years), AVF was associated with survival benefit only in male (p < 0.001) and diabetic (p = 0.04) patients, and with better access patency only in female (p = 0.05) and diabetic (p = 0.04) patients. AVG (vs. AVF; HR 3.158; 95% CI 1.080-9.238; p = 0.036) was associated with poor patient survival. In septuagenarian patients, AVF was associated only with survival benefit (p = 0.01) and there was no advantage in access patency (p = 0.12). However, AVF was superior to AVG in both access patency (p = 0.001) and patient survival (p = 0.03) even with propensity matching. Conclusion: AVF is the more desirable VA and its survival benefits warrant its consideration in septuagenarian patients although a prolonged life expectancy is essential to realize the potential benefits of AVF.

BackgroundThe impact of timing of dialysis initiation on mortality is controversial in patients with peritoneal dialysis (PD). In this study, we analyzed the impact of timing of dialysis initiation on mortality in the incident PD population.MethodsIncident patients with PD were selected from the Clinical Research Center (CRC) registry for end-stage renal disease (ESRD), a prospective cohort study on dialysis in Korea. Patients were categorized into 3 groups according to the estimated glomerular filtration rate (eGFR) at the initiation of PD using the Modification of Diet in Renal Disease (MDRD) equation. Group A was defined as eGFR < 5 mL/min/1.73m2, group B as eGFR 5 – 10 mL/min/1.73m2, and group C as eGFR > 10 mL/min/1.73m2. Cox regression analysis was used to calculate the adjusted hazard ratio (HR) of mortality with group B as the reference. The primary outcome was all-cause mortality.ResultsA total of 495 incident PD patients were included. The number of patients in group A was 109, group B was 279, and group C was 107. The median follow-up period was 23 months. Multivariate Cox regression analysis showed that group A had a significantly higher risk of all-cause mortality compared with group B (HR 4.13, 95% confidence interval [CI], 1.55 – 11.03, p = 0.005) after adjustment for age, gender, cause of ESRD, serum albumin level, diabetes mellitus, and cardiovascular disease. There was no significant difference in mortality between group C and group B (HR 1.50, 95% CI, 0.59 – 3.80, p = 0.398) after adjustment for clinical variables.ConclusionAn eGFR < 5 mL/min/1.73m2at the initiation of PD was a significant risk factor for death, while an eGFR >10 mL/min/1.73m2at the initiation of PD was not associated with improved survival compared with an eGFR of 5 – 10 mL/min/1.73m2at the initiation of PD.

The Korean Society of Nephrology (KSN) launched a nationwide official survey program about dialysis therapy in 1985. Nowadays, the accumulated data for 30 years by this “Insan Prof. Min Memorial end-stage renal disease (ESRD) Registry” program have been providing the essential information for dialysis clinical practice, academic nephrology research, and health management policy. We reviewed 30 years of data to identify important changes and implications for the future improvement of dialysis therapy in Korea.Hemodialysis patients, especially diabetics and elderly patients have increased in number very rapidly during recent years in Korea. The Korean prevalence rate of ESRD patients was about 70% of the United States and about 50% of Japan according to the international comparisons in the annual data report of United States Renal Data System. The blood pressure control, anemia control, and dialysis adequacy have continuously improved year by year. The importance of calcium and phosphorus control has also been increasing because of the increase in long-term dialysis patients. In addition, chronic dialysis complications should be closely monitored and dialysis modifications, such as hemodiafiltration therapy, might be considered. Because of the increase of private clinics and nursing hospitals in dialysis practice, the role of dialysis specialists and continuing education are thought to be essential. For strict cost-effective dialysis control of increasing elderly, diabetic, and long-term dialysis patients, the KSN ESRD patient registration should be run by the KSN and health ministry in cooperation, in which the dialysis fee reimbursement should be accompanied.

The Korean Society of Nephrology (KSN) end-stage renal disease (ESRD) registry was established in 1985 in which all KSN members are participating voluntarily: the ‘Insan Prof. Byung-Suk Min Memorial ESRD Patient Registry'. The ESRD registry committee of KSN has collected the data through the internet online program that was opened in 2001 and revised in 2013. The registry internet program has collected data throughout the years, which includes dialysis center information, vascular access, dialysis doses, and laboratory data with dialysis adequacy and rehabilitation status. In Korea, the number of dialysis patients has been rapidly growing (~8–9% per year) in recent years, especially elderly patients. The total number of patients with renal replacement therapy (RRT) was 75,042 at the end of 2013. The prevalence of RRT was 1446.4 patients per million population. The proportion of RRT for hemodialysis (HD) is 69.8%, for peritoneal dialysis (PD) is 10.0%, and for renal transplant is 20.2%. In about half (48%) of new dialysis patients, the underlying disease was diabetic nephropathy in 2013. Mean urea reduction ratio in HD was 68.1% in male patients and 74.2% in female patients. Survey on rehabilitation status of dialysis patients showed that 22% of HD patients have full-time job and 8% have part-time job. About 29% of PD patients have full-time job and 17% have part-time job.

Background: Considering that contrast medium is excreted through the whole kidney in a similar manner to drug excretion, the use of raw estimated glomerular filtration rate (eGFR) rather than body surface area (BSA)-normalized eGFR is thought to be more appropriate for evaluating the risk of contrast-induced acute kidney injury (CI-AKI). Methods: This study included 2,189 myocardial infarction patients treated with percutaneous coronary intervention. Logistic regression analysis was performed to identify the independent risk factors. We used receiver-operating characteristic (ROC) curves to compare the ratios of contrast volume (CV) to eGFR with and without BSA normalization in predicting CI-AKI. Results: The area under the curve (AUC) of the ROC curve for the model including all the significant variables such as diabetes mellitus, left ventricular ejection fraction, preprocedural glucose, and the CV/raw modification of diet in renal disease (MDRD) eGFR ratio was 0.768 [95% confidence interval (CI), 0.720-0.816; p < 0.001]. When the CV/raw MDRD eGFR ratio was used as a single risk value, the AUC of the ROC curve was 0.650 (95% CI, 0.590-0.711; p < 0.001). When the CV/MDRD eGFR ratio with BSA normalization ratio was used, the AUC of the ROC curve further decreased to 0.635 (95% CI, 0.574-0.696; p < 0.001). The difference between the two AUCs was significant (p = 0.002). Conclusions: Raw eGFR is a better predictor for CI-AKI than BSA-normalized eGFR.

Background/Aims: β2-Microglobulin (β2-M) is a surrogate marker of middle-molecule uremic toxins and is associated with mortality in chronic hemodialysis patients. However, the impact of serum β2-M levels on mortality in peritoneal dialysis (PD) patients is uncertain. The purpose of this study was to examine the association of serum β2-M levels with all-cause mortality in PD patients. Methods: A total of 771 PD patients were selected from the Clinical Research Center registry for end-stage renal disease cohort in Korea. Patients were categorized into 3 groups by tertiles of serum β2-M levels. The primary outcome was all-cause mortality. Results: The median value of serum β2-M was 23.6 mg/l (interquartile range 14.8-33.4 mg/l), and the median follow-up period was 39 months. The Kaplan-Meier analysis showed that the all-cause mortality rate was significantly different according to tertiles of serum β2-M in PD patients (p = 0.03, log-rank). Multivariate Cox proportional analysis showed that the hazards ratio for all-cause mortality was 1.02 (95% CI 1.01-1.04, p = 0.006) per 1 mg/l increase in β2-M after adjustment for multiple confounding factors that relate to malnutrition and inflammation marker. However, serum β2-M was not associated with all-cause mortality after adjustment for residual renal clearance. Conclusions: These results are supportive of the potential role of the serum β2-M level as a predictor of mortality in PD patients.

Because of increases in the elderly population and diabetic patients, the proportion of elderly among dialysis patients has rapidly increased during the last decades. The mortality and morbidity of these elderly dialysis patients are obviously much higher than those of young patients, but large analytic studies about elderly dialysis patients' characteristics have rarely been published. The registry committee of the Korean Society of Nephrology has collected data about dialysis therapy in Korea through an Internet online registry program and analyzed the characteristics. A survey on elderly dialysis patients showed that more than 50% of elderly (65 years and older) patients had diabetic nephropathy as the cause of end-stage renal disease, and approximately 21% of elderly dialysis patients had hypertensive nephrosclerosis. The proportion of elderly hemodialysis (HD) patients with native vessel arteriovenous fistula as vascular access for HD was lower than that of young (under 65 years) HD patients (69% vs. 80%). Although the vascular access was poor and small surface area dialyzers were used for the elderly HD patients, the dialysis adequacy data of elderly patients were better than those of young patients. The laboratory data of elderly dialysis patients were not very different from those of young patients, but poor nutrition factors were observed in the elderly dialysis patients. Although small surface area dialyzers were used for elderly HD patients, the urea reduction ratio and Kt/V were higher in elderly HD patients than in young patients.

The Korean Society of Nephrology (KSN) launched the official end-stage renal disease (ESRD) patient registry in 1985, and an Internet online registry program was opened in 2001 and revised in 2013. The ESRD Registry Committee of KSN has collected data on dialysis therapy in Korea through the online registry program in the KSN Internet website. The status of renal replacement therapy in Korea at the end of 2012 is described in the following. The total number of ESRD patients was 70,211 at the end of 2012, which included 48,531 hemodialysis (HD) patients, 7,552 peritoneal dialysis (PD) patients, and 14,128 functioning kidney transplant (KT) patients. The prevalence of ESRD was 1,353.3 patients per million population (PMP), and the distribution of renal replacement therapy among ESRD patients was as follows: HD, 69.1%; PD, 10.8%; and KT, 20.2%. The number of new ESRD patients in 2012 was 11,742 (HD, 8,811; PD, 923; and KT, 1,738; the incidence rate was 221.1 PMP). The primary causes of ESRD were diabetic nephropathy (50.6%), hypertensive nephrosclerosis (18.5%), and chronic glomerulonephritis (18.1%). The mean urea reduction ratio was 67.9% in male and 74.1% in female HD patients. The mean Kt/V was 1.382 in male and 1.652 in female HD patients. The 5-year survival rates of male and female dialysis patients were 70.6% and 73.5%, respectively.

To increase the rate of arteriovenous fistula (AVF) use, assisted procedures for immature AVF have been strenuously performed. However, this is controversial in that an AVF matured by these assisted procedures may require more frequent intervention to maintain its patency, and have decreased long-term patency.Eighty four AVFs that were matured with assisted maturation procedures and 266 AVFs that matured spontaneously without intervention, created between November 2009 and March 2013 from the hemodialysis (HD) vascular access (VA) cohort, were compared retrospectively and we also investigated the factors that may influence AVF long-term patency. Median follow-up was 26.8 months (interquartile range, 6.6-45.0 months).Access survival did not differ between AVFs matured by assisted procedures and spontaneously mature AVFs (P = 0.29). In multivariate Cox regression analysis of AVF survival, age (HR, 1.029; 95% CI, 1.004-1.056; P = 0.024), maturation without assisted procedures 4-6 weeks after AVF creation (HR, 0.233; 95% CI, 0.107-0.506; P 0.001), and AVF thrombosis (HR, 26.511; 95% CI, 10.986-63.978; P 0.001) were significantly associated with AVF survival. Performance of assisted procedures to induce AVF maturation did not influence AVF survival (HR, 0.437; 95% CI, 0.191-1.002; P = 0.05).Our results support that idea that assisted maturation procedures can ensure the success of immature AVF without compromising long-term patency. These procedures can be considered more positively for increasing AVF use for VA placement in HD patients.

Residual kidney function (RKF) contributes to improved survival in hemodialysis (HD) patients. However, it is not clear whether RKF allows a comparable survival rate in patients undergoing twice-weekly HD compared with thrice-weekly HD. We enrolled 685 patients from a prospective multicenter observational cohort. RKF and HD adequacy was monitored regularly over 3-year follow-up. Patients with RKF were divided into groups undergoing twice-weekly HD (n = 113) or thrice-weekly HD (n = 137). Patients without RKF undergoing thrice-weekly HD (n = 435) were included as controls. Fluid balance and dialysis-associated characteristics were followed and clinical outcomes evaluated using all-cause mortality and cardiovascular events (CVE). In patients with RKF, baseline and follow-up RKF were significantly higher in patients undergoing twice-weekly HD than in those undergoing thrice-weekly HD. Total Kt/V urea (dialysis plus residual renal) in patients with RKF undergoing twice-weekly HD was greater than or equal to those in patients with or without RKF undergoing thrice-weekly HD. Compared with patients with RKF undergoing thrice-weekly HD, patients with RKF undergoing twice-weekly HD had no fluid excess, but their normalized protein catabolic rate became lower since 24-month follow up. In multivariable analyses, patients with RKF undergoing twice-weekly HD had a noninferior risk of mortality (hazard ratio [HR], 0.83; 95% confidence interval [95% CI], 0.34–2.01, P = 0.68) and of CVE (HR, 0.60; 95% CI, 0.28–1.29, P = 0.19) compared with patients without RKF undergoing thrice-weekly HD. However, this group showed an independent association with a greater risk of mortality compared with patients with RKF undergoing thrice-weekly HD (HR, 4.20; 95% CI, 1.02–17.32, P = 0.04). In conclusion, patients with RKF undergoing twice-weekly HD had an increased risk of mortality compared with those undergoing thrice-weekly HD. Decisions about twice-weekly HD should consider not only RKF, but also other risk factors such as normalized protein catabolic rate.

The Korean Society of Nephrology (KSN) launched the official End-Stage Renal Disease (ESRD) Patient Registry in 1985 and the Internet online registry program was opened in 2001. The ESRD Registry Committee of KSN has collected data on dialysis therapy in Korea through the online registry program in the KSN Internet website. The increasing number of elderly people and diabetic patients in Korea has resulted in a very rapid increase in the number of ESRD patients. The total number of ESRD patients was 58,860 (hemodialysis [HD], 39,509; peritoneal dialysis [PD], 7309; and functioning kidney transplant [KT], 12,042). The prevalence of ESRD was 1144.4 patients per million population (PMP), and the proportion of renal replacement therapy was HD, 67.1%; PD, 12.4%; and KT, 20.5%. The number of new ESRD patients in 2010 was 9335 (HD, 7204; PD, 867; and KT, 1264; the incidence rate was 181.5 PMP). The primary causes of ESRD were diabetic nephropathy (45.2%), hypertensive nephrosclerosis (19.2%), and chronic glomerulonephritis (11.3%). The mean urea reduction ratio was 67.9% in male HD patients and 73.9% in female HD patients. The mean Kt/V was 1.394 in male patients and 1.659 in female patients. Five-year survival rates of male and female dialysis patients were 64.9% and 67.3%, respectively.

Although inducible nitric oxide synthase (iNOS) is known to play significant roles in the kidney, its renal localization has long been controversial. To resolve this issue, the authors identified iNOS-positive cell types in rat kidneys using double immunohistochemistry and confirmed iNOS positivity using enzyme histochemistry with NADPH-diaphorase (NADPH-d) and in situ RT-PCR. Adult male Sprague-Dawley rats were injected intraperitoneally with lipopolysaccharide (LPS) or saline as a control and sacrificed at various time intervals after injection. Quantitative real-time reverse transcriptase polymerase chain reaction showed that iNOS was not expressed in control kidneys but was induced in LPS-treated kidneys. iNOS immunostaining was strongest 6 to 18 hr after injection and decreased gradually to control levels by day 7. Double immunohistochemistry and NADPH-d revealed that iNOS expression was induced in the interstitial cells, glomerular parietal epithelial cells, the proximal part of the short-looped descending thin limb, the upper and middle papillary parts of the long-looped descending thin limb, some inner medullary collecting duct cells, and almost all calyceal and papillary epithelial cells. The present study determines the precise localization of iNOS in LPS-treated rat kidneys and provides an important morphological basis for examining the roles of iNOS in sepsis-induced acute kidney injury.

Our previous research demonstrated that calponin-immunoreactivity was localized in myofibroblasts of the periglomerular region of human kidney specimens obtained at the time of transplantation from organ recipients. In the present study we examined calponin expression in two chronic nephropathy models, puromycin aminonucleoside (PAN) nephropathy and subtotal nephrectomy (SNx), to investigate the role of calponin in chronic renal injury. Male Sprague-Dawley rats were used, and both nephropathy models were established at 1, 2, 4, and 8 weeks after surgery. There were no periglomerular calponin-positive cells in sham, PAN 1 and 2 week, and SNx 1, 2, and 4 week groups. In SNx 8 week and PAN 4 and 8 week groups, only a few glomeruli with periglomerular calponin-reactivity, which covered half or a very small part of the periglomerular space, were observed. All glomeruli with periglomerular calponin-reactivity showed sclerotic changes, especially thickening of parietal epithelial cells (PECs). In conjunction with our previous report, this data represents the first documentation of the expression of calponin in renal myofibroblasts. We suggest that interactions between PECs and calponin-positive myofibroblasts may play a key role in the late stage of glomerulosclerosis.

Chronic kidney disease (CKD) is a significant risk factor for contrast induced acute kidney injury (CI-AKI) after percutaneous coronary intervention (PCI). This study included 1592 CKD patients extracted from a prospective multicenter, all comer-based registry of patients undergoing PCI. In multivariate logistic analysis for CI-AKI development, a significant linear trend was observed between the quartiles of HDL-C (quartile 1 vs. 2: odds ratio [OR], 0.716; 95% confidence interval [CI], 0.421–1.219; quartile 1 vs. 3: OR, 0.534; 95% CI, 0.301–0.947; quartile 1 vs. 4: OR, 0.173; 95% CI, 0.079–0.377; P for trend 48 mg/dL) respectively (P P = 0.007). Our study suggests more intensive strategies should be considered for preventing CI-AKI in CKD patients with low serum HDL-C level who is planned for PCI.

Background Serum alkaline phosphatase (ALP) levels have been reported to be associated with all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients. However, it is unclear whether serum ALP levels predict infection-related clinical outcomes in PD patients. The aim of this study was to determine the relationships between serum ALP levels, infection-related mortality and hospitalization in PD patients. Methods PD patients from the Clinical Research Center registry for end-stage renal disease, a multicenter prospective observational cohort study in Korea, were included in the present study. Patients were categorized into three groups by serum ALP tertiles as follows: Tertile 1, ALP 155 U/L. Tertile 1 was used as the reference category. The primary outcomes were infection-related mortality and hospitalization. Results A total of 1,455 PD patients were included. The median follow-up period was 32 months. The most common cause of infection-related mortality and hospitalization was PD-related peritonitis. Multivariate Cox regression analyses showed that patients in the highest tertiles of serum ALP levels were at higher risk of infection-related mortality (HR 2.29, 95% CI, 1.42-5.21, P = 0.008) after adjustment for clinical variables. Higher tertiles of serum ALP levels were associated with higher risk of infection-related hospitalization (Tertile 2: HR 1.56, 95% CI, 1.18-2.19, P = 0.009, tertile 3: HR 1.34, 95% CI, 1.03-2.62, P = 0.031). Conclusions Our data showed that elevated serum ALP levels were independently associated with a higher risk of infection-related mortality and hospitalization in PD patients.

The association between dialysate calcium (DCa) concentration and mortality in hemodialysis (HD) patients is controversial. In this study, we evaluated the impact of DCa concentration on mortality in incident HD patient. Incident HD patients were selected from the Clinical Research Center registry—a prospective cohort study on dialysis patients in Korea. Patients were categorized into 3 groups according to the prescribed DCa concentration at the time of enrollment. High DCa was defined as a concentration of 3.5 mEq/L, mid-DCa as 3.0 mEq/L, and low DCa as 2.5 to 2.6 mEq/L. The primary outcome was all-cause mortality and secondary outcomes were cardiovascular or infection-related hospitalization. A total of 1182 patients with incident HD were included. The number of patients in each group was 182 (15.4%) in high DCa group, 701 (59.3%) in the mid-DCa group, and 299 (25.3%) in the low DCa group. The median follow-up period was 16 months. The high DCa group had a significantly higher risk of all-cause mortality compared with the mid-DCa group (hazard ratio [HR] 2.23, 95% confidence interval [CI] 1.28–3.90, P = 0.005) and the low DCa group (HR 3.67, 95% CI 1.78–7.55, P

Erythropoiesis-stimulating agent (ESA) responsiveness has been reported to be associated with increased mortality in hemodialysis (HD) patients. ESA requirement to obtain the same hemoglobin (Hb) level is different between HD and peritoneal dialysis (PD) patients. In this study, we investigated the impact of ESA responsiveness on mortality between both HD and PD patients. Prevalent HD and PD patients were selected from the Clinical Research Center registry for end-stage renal disease, a prospective cohort study in Korea. ESA responsiveness was estimated using an erythropoietin resistant index (ERI) (U/kg/week/g/dL). Patients were divided into three groups by tertiles of ERI. ESA responsiveness was also assessed based on a combination of ESA dosage and hemoglobin (Hb) levels. The primary outcome was all-cause mortality. A total of 1,594 HD and 876 PD patients were included. The median ESA dose and ERI were lower in PD patients compared with HD patients (ESA dose: 4000 U/week vs 6000 U/week, respectively. P

Background: High-mobility group box1 (HMGB1) is known to be involved in innate immune response through interaction with receptor for advanced glycation end products (RAGE) and toll-like receptors (TLRs), besides its proper role within the nucleus. Immunological pathways, including TLR signaling, are also involved in chronic cyclosporine (CsA) nephrotoxicity. This study was designed to determine whether neutralizing HMGB1 prevents chronic CsA nephrotoxicity. Methods: Chronic CsA nephrotoxicity was induced by CsA subcutaneous injection daily for 4 weeks under salt-depletion in mice. Anti-HMGB1 neutralizing antibody for HMGB1 blockade (600 mcg/mouse) was administered weekly to mice in the anti-HMGB1 treatment group. The effects of HMGB1 neutralization were evaluated in terms of renal function as well as histological and immunopathological examination. Results: Anti-HMGB1 administration prevented the increases in serum creatinine and 24 h albuminuria and the decrease in creatinine clearance associated with CsA treatment. Increased tubulointerstitial fibrosis and transforming growth factor (TGF)-β immunohistochemical staining associated with CsA treatment were also prevented by anti-HMGB1 administration. Anti-HMGB1 administration prevented the activation of the TLR4 signaling pathway, which resulted in the reduction of nuclear factor kappa B (NF-κB) expression. In cultured tubular cells, anti-HMGB1 pretreatment also prevented the increases in fibronectin and collagen IV levels associated with CsA treatment. Conclusions: Neutralizing HMGB1 with an anti-HMGB1 antibody ameliorated chronic CsA nephrotoxicity via inhibition of the TLR4 signaling pathway. Our study suggests that HMGB1 blockade can be beneficial for increasing allograft survival in renal transplant recipients by protecting against calcineurin inhibitor-induced nephrotoxicity.