End-stage Renal Disease In Korea Research Articles

Status and trends in epidemiologic characteristics of diabetic end-stage renal disease: an analysis of the 2021 Korean Renal Data System.

Korean Renal Data System (KORDS) is a nationwide end-stage renal disease (ESRD) registry database operated by the Korean Society of Nephrology (KSN). Diabetes mellitus is currently the leading cause of ESRD in Korea; this article provides an update on the trends and characteristics of diabetic ESRD patients. The KORDS Committee of KSN collects data on dialysis centers and patients through an online registry program. Here, we analyzed the status and trends in characteristics of diabetic chronic kidney disease stage 5D (CKD 5D) patients using data from 2001 to 2021. In 2021, the dialysis adequacy of hemodialysis (HD) was lower in diabetic CKD 5D patients than in nondiabetic CKD 5D patients, while that of peritoneal dialysis (PD) was similar. Diabetic CKD 5D patients had a higher proportion of cardiac and vascular diseases and were more frequently admitted to hospitals than nondiabetic CKD 5D patients, and the leading cause of death was cardiac disease. From 2001 to 2020, diabetic CKD 5D patients had a higher mortality rate than nondiabetic CKD 5D patients, but in 2021 this trend was reversed. Diabetic PD patients had the highest mortality rate over 20 years. The mortality rate of diabetic HD patients was higher than that of nondiabetic HD patients until 2019 but became lower starting in 2020. There was a decreasing trend in mortality rate in diabetic CKD 5D patients, but cardiac and vascular diseases were still prevalent in diabetic CKD 5D patients with frequent admissions to hospitals. More specialized care is needed to improve the clinical outcomes of diabetic CKD 5D patients.

Comparison of out-of-pocket expenditure and catastrophic health expenditure for severe disease by the health security system: based on end-stage renal disease in South Korea

BackgroundKorea’s health security system named the National Health Insurance and Medical Aid has revolutionized the nation’s mandatory health insurance and continues to reduce excessive copayments. However, few studies have examined healthcare utilization and expenditure by the health security system for severe diseases. This study looked at reverse discrimination regarding end-stage renal disease by the National Health Insurance and Medical Aid.MethodsA total of 305 subjects were diagnosed with end-stage renal disease in the Korea Health Panel from 2008 to 2013. Chi-square, t-test, and ANCOVA were conducted to identify the healthcare utilization rate, out-of-pocket expenditure, and the prevalence of catastrophic expenditure. Mixed effect panel analysis was used to evaluate total out-of-pocket expenditure by the National Health Insurance and Medical Aid over a 6-year period.ResultsThere were no significant differences in the healthcare utilization rate for emergency room visits, admissions, or outpatient department visits between the National Health Insurance and Medical Aid because these healthcare services were essential for individuals with serious diseases, such as end-stage renal disease. Meanwhile, each out-of-pocket expenditure for an admission and the outpatient department by the National Health Insurance was 2.6 and 3.1 times higher than that of Medical Aid (P < 0.05). The total out-of-pocket expenditure, including that for emergency room visits, admission, outpatient department visits, and prescribed drugs, was 2.9 times higher for the National Health Insurance than Medical Aid (P < 0.001). Over a 6-year period, in terms of total of out-of-pocket expenditure, subjects with the National Health Insurance spent more than those with Medical Aid (P < 0.01). If the total household income decile was less than the median and subjects were covered by the National Health Insurance, the catastrophic health expenditure rate was 92.2%, but it was only 58.8% for Medical Aid (P < 0.001).ConclusionIndividuals with serious diseases, such as end-stage renal disease, can be faced with reverse discrimination depending on the type of insurance that is provided by the health security system. It is necessary to consider individuals who have National Health Insurance but are still poor.

The Nationwide Incidence of Retinal Vein Occlusion Following Dialysis due to End-stage Renal Disease in Korea, 2004 through 2013.

BackgroundWe investigated the incidence and risk of retinal vein occlusion (RVO) in end-stage renal disease (ESRD) patients on dialysis in Korea.MethodsIn this nationwide cohort study, we used Korean National Health Insurance Service data between 2004 and 2013 for analysis. ESRD patients who started dialysis from 2004 to 2013 and an equal number of controls were selected through propensity score matching. RVO incidence in both cohorts were calculated for 2004–2013 using washout data from 2003. The multivariable Cox proportional hazards model was used to assess the risk of RVO in dialysis cohort. The Kaplan-Meier method was used to generate the cumulative RVO incidence curve. Whether the dialysis modality affects the development of RVO was also evaluated.ResultsIn this study, 74,551 ESRD patients on dialysis and the same number of controls were included. The incidence of RVO was significantly higher in the dialysis cohort than in the control cohort (dialysis = 7.3/1,000 person-years [PY]; control = 1.9/1,000 PY; P < 0.001). The cumulative-incidence of RVO was also significantly higher in the dialysis cohort than in the control cohort (P < 0.001; log-rank test). However, there was no significant difference in the incidence of RVO between the two dialysis methods (P = 0.550; log-rank test).ConclusionThis study provided epidemiological evidence that receiving dialysis for ESRD could increase the risk of developing RVO. We also found a rapid increase in the incidence of RVO with a longer dialysis period. These results strengthen the relationship between retinal vascular disease and renal function.

Metronidazole therapy as initial treatment of Clostridium difficile infection in patients with chronic kidney disease in Korea.

The risk of metronidazole treatment failure in Clostridium difficile infection (CDI) patients with chronic kidney disease (CKD) or end-stage renal disease in Korea has not been established. We evaluated 481 patients who had been admitted to two secondary hospitals with a diagnosis of, and treatment for, CDI during 2010-2016. CDI patients were divided into three groups according to CKD status: non-CKD (n = 363), CKD (n = 55) and those requiring dialysis (n = 63). Logistic regression analyses were performed to examine the association of CKD status with treatment failure. CDI patients receiving dialysis tended to have increased odds of metronidazole and overall treatment failure compared to non-CKD patients; adjusted odds ratios and 95% confidence intervals were 2.09 (1.03-4.21) and 2.18 (1.11-4.32) for metronidazole and overall treatment failure, respectively. However, CKD patients did not have increased odds of metronidazole or overall treatment failure compared to non-CKD patients, even where severe CDI was more prevalent in CKD patients. The incidence of symptomatic ileus or toxic megacolon did not differ among groups. Our results suggest that initial metronidazole therapy may be considered in CDI patients with non-dialysis CKD, but should not be considered in CDI patients undergoing dialysis.

Current treatment status and medical costs for hemodialysis vascular access based on analysis of the Korean Health Insurance Database.

Background/AimsThe Republic of Korea is a country where the hemodialysis population is growing rapidly. It is believed that the numbers of treatments related to vascular access-related complications are also increasing. This study investigated the current status of treatment and medical expenses for vascular access in Korean patients on hemodialysis.MethodsThis was a descriptive observational study. We inspected the insurance claims of patients with chronic kidney disease who underwent hemodialysis between January 2008 and December 2016. We calculated descriptive statistics of the frequencies and medical expenses of procedures for vascular access.ResultsThe national medical expenses for access-related treatment were 7.12 billion KRW (equivalent to 6.36 million USD) in 2008, and these expenses increased to 42.12 billion KRW (equivalent to 37.67 million USD) in 2016. The population of hemodialysis patients, the annual frequency of access-related procedures, and the total medical cost for access-related procedures increased by 1.6-, 2.6-, and 5.9-fold, respectively, over the past 9 years. The frequency and costs of access care increased as the number of patients on hemodialysis increased. The increase in vascular access-related costs has largely been driven by increased numbers of percutaneous angioplasty.ConclusionsThe increasing proportion of medical costs for percutaneous angioplasty represents a challenge in the management of end-stage renal disease in Korea. It is essential to identify the clinical and physiological aspects as well as anatomical abnormalities before planning angioplasty. A timely surgical correction could be a viable option to control the rapid growth of access-related medical expenses.

Three-year income trends in Korean adults commencing haemodialysis: A prospective cohort.

This study aimed to explore the trends in individual income and to estimate the change in average monthly income for patients undergoing haemodialysis therapy. The main data source was the Clinical Research Center (CRC) for End-Stage Renal Disease in Korea. In addition to the cohort data, a survey was conducted to capture personal income for 3 years. To estimate the change in monthly income over time using repeated measures, a random coefficient model using penalized quasi-likelihood methods based on restricted or residual maximum likelihood estimation was used. During the 3-year study period, 138 subjects aged 20 and over who answered the question about pre-dialysis income were traced and analyzed. The median value of monthly income was $US564.4 in the 1st year, $470.4 in the 2nd year, and $733.8 in the 3rd year, representing a 70%, 75%, and 61% decrease compared to pre-dialysis income ($1881.5), respectively. By using mixed analysis, we found that monthly income change was $1283 (95% CI, -1621.5, -945.1), $1182 USD (95% CI, -1540.8, -823.1), and $1041 (95% CI, -1457.6, -623.6) in the 1st , 2nd , and 3rd year, respectively, compared to pre-dialysis income after controlling for other covariates. Women and less educated patients had a relatively higher reduction of income, despite the low starting point. The monthly income of dialysis patients reduced substantially over the study period, especially at the time of the first survey. Considering the social security system, haemodialysis patients face significant personal financial burdens due to their ESRD unrelated to the direct costs of dialysis treatment.

Cancer in Korean patients with end-stage renal disease: A 7-year follow-up.

BackgroundThe effectiveness of dialysis on the incidence of cancer in patients with end-stage renal disease (ESRD) remains to be clarified. In this study, we evaluated the incidence rate and type of cancer among patients with ESRD, compared to the general population, through a prospective 7-year follow-up. We also calculated the cumulative incidence rate of cancer associated with ESRD, with stratification to control for the competing risk of death.MethodsThis prospective observational cohort study was conducted using data from a nationwide study on patients with ESRD in Korea. A total of 5,235 patients, ≥18 years old, with ESRD were identified from the national registry as being treated by dialysis between August 2008 and December 2014. The standardized incidence ratio (SIR) and cumulative incidence rate of specific cancers were evaluated and compared to the general population.ResultsA total of 5,235 participants were included. During the 7 year observation period, 116 (2.2%) participants had been diagnosed as cancer. The SIR of overall cancer was 0.94 [95% confidence interval (CI), 0.72–1.19] and was comparable to the rate for the general population. Although the digestive organs were the most frequent site of a primary site cancer (N = 39, 33.6%), the SIR was highest for urinary tract cancer [4.7, 95% CI, 2.42–8.19]. The five year standardized cumulative incidence of cancer was higher for females than for males, and for non-diabetic compared to diabetic causes of ESRD. We estimated that the five year standardized cumulative incidence was highest [8.4, 95% CI, 5.07–13.75] in patients with ESRD, caused by glomerulonephritis.ConclusionA screening program should be necessary for urinary tract cancer in Korean patients with ESRD. Cancer screening programs for patients with ESRD in Korea should be emphasized on female patients and patients with non-diabetic ESRD.

Treatment of diabetic kidney disease: current and future targets.

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease in Korea and worldwide, and is a risk factor for the development of cardiovascular complications. The conventional treatments for DKD are control of blood glucose and blood pressure levels by inhibiting the renin-angiotensin system. However, the prevalence of DKD continues to increase and additional therapies are required to prevent or ameliorate the condition. Many drugs have been, or are being, developed to target the molecular mechanisms in play in DKD. This review focuses on DVD treatment, considering current and emerging therapeutic targets and the clinical trial-based evidence.

Outcomes of dialysis and the transplantation options for patients with diabetic end-stage renal disease in Korea.

The best therapeutic option for diabetic end-stage renal disease (DMESRD) has not been established among living donor kidney transplantation (LDKT), deceased donor kidney transplantation (DDKT), simultaneous pancreas and kidney transplantation (SPK), and dialysis. We retrospectively analyzed the outcomes of DMESRD patients at two Korean centers from February 2000 to December 2011. Among 674 patients, 295 underwent kidney transplantation (LDKT, 175; DDKT, 72; and SPK, 48), while 379 were still on dialysis. The dialysis group had a higher mortality rate than the transplantation group. From the time after dialysis initiation, LDKT group had a better patient survival rate than DDKT registration group and SPK registration group. From the time after transplantation, LDKT had a better patient survival rate than DDKT; however, there was no significant difference between LDKT and SPK. In SPK, patient survival and kidney or pancreas graft survival rates were not different between types 1 and 2 DMESRD. LDKT is better than waiting for SPK/DDKT in DMESRD patients, if a living donor is available, and this conclusion may be unique to Korea where waiting time for SPK is long. SPK can be used in non-obese Asians with type 2 as well as type 1 DMESRD.

Glycemic Control and Mortality in Diabetic Patients Undergoing Dialysis Focusing on the Effects of Age and Dialysis Type: A Prospective Cohort Study in Korea.

BackgroundActive glycemic control has been proven to delay the onset and slow the progression of diabetic retinopathy, nephropathy, and neuropathy in diabetic patients, but the optimal level is obscure in end-stage renal disease. In this study, we evaluated the effect of hemoglobin A1c (HbA1c) on mortality of diabetic patients on dialysis, focusing on age and dialysis type.MethodsOf 3,302 patients enrolled in the prospective cohort for end-stage renal disease in Korea between August 2008 and October 2013, 1,239 diabetic patients who had been diagnosed with diabetes or having HbA1c≥6.5% at the time of enrollment were analyzed. Age was categorized as <55, 55–64 and ≥65 years old. Age, sex, modified Charlson comorbidity index, hemoglobin, primary renal disease, body mass index, and dialysis duration were adjusted.ResultsA total of 873 patients received hemodialysis (HD) and 366 underwent peritoneal dialysis (PD). During the mean follow-up of 19.1 months, 141 patients died. Patients with poor glucose control (HbA1c≥8%) showed worse survival than patients with HbA1c<8% (hazard ratio [HR], 2.2; 95% confidence interval [CI], 1.48–3.29; P<0.001). Subgroup analysis divided by age revealed that HbA1c≥8% was a predictor of mortality in age <55 (HR, 4.3; 95% CI, 1.78–10.41; P = 0.001) and age 55–64 groups (HR, 3.3; 95% CI, 1.56–7.05; P = 0.002), but not in age ≥65 group. Combining dialysis type and age, poor glucose control negatively affected survival only in age < 55 group among HD patients, but it was significant in age < 55 and age 55–64 groups in PD patients. Deaths from infection were more prevalent in the PD group, and poor glucose control tended to correlate with more deaths from infection in PD patients (P = 0.050).ConclusionsIn this study, the effect of glycemic control differed according to age and dialysis type in diabetic patients. Thus, the target of glycemic control should be customized; further observational studies may strengthen the clinical relevance.

Interdialytic Weight Gain and Cardiovascular Outcome in Incident Hemodialysis Patients

Background: Interdialytic weight gain (IDWG) has been regarded as a surrogate of volume overload, but also as a marker of a better nutritional status in end-stage renal disease (ESRD) patients on hemodialysis (HD). This paradoxical meaning of IDWG requires further investigation, particularly in adverse cardiovascular outcomes. Methods: A prospective cohort of 1,013 incident HD patients from 36 HD centers of the Clinical Research Center for ESRD in Korea was included. Patients were categorized into five groups according to the IDWG%, a ratio of absolute IDWG to dry weight: <1.0, ≥4.0, and every 1.0 increment in between. Primary outcome was major adverse cardiac and cerebrovascular events (MACCE). Results: During a mean follow-up of 18.7 months, primary outcome was observed in 104 patients (10.3%). In multivariate analysis, compared to patients with IDWG% of 1.0-1.9 (reference group), the hazard ratios (HRs) for primary outcome in the IDWG% <1.0, 2.0-2.9, 3.0-3.9, and ≥4.0 groups were 1.10 [95% confidence interval (CI) 0.55-2.20, p = 0.80], 1.15 (95% CI 0.59-2.27, p = 0.68), 1.80 (95% CI 0.95-3.41, p = 0.07), and 1.93 (95% CI 1.02-3.64, p = 0.04), respectively. Furthermore, even when residual renal function and 24-hour urine volume were adjusted, IDWG% ≥4.0 remained as a significant predictor of primary outcome (HR 2.03, 95% CI 1.02-4.02, p = 0.04). Conclusion: Increased IDWG% is a significant independent predictor of MACCE in incident HD patients. It could be helpful to prevent excessive IDWG for improving clinical outcomes in incident HD patients.

The Relationship of Initial Transferrin Saturation to Cardiovascular Parameters and Outcomes in Patients Initiating Dialysis

BackgroundThe prognostic importance of anemia for cardiovascular (CV) events and mortality has been extensively investigated. However, little is known about the impact of transferrin saturation (TSAT), a marker reflecting the availability of iron for erythropoiesis, on clinical outcome in dialysis patients.MethodsA total of 879 anemic incident dialysis patients were recruited from the Clinical Research Center for End-Stage Renal Disease in Korea and were divided into 3 groups according to baseline TSAT of ≤20%, 20–40%, and >40%.ResultsThere were no differences in hemoglobin levels and the proportion of patients on erythropoiesis-stimulating agents or iron supplements among the 3 groups. During a mean follow-up duration of 19.3 months, 51 (5.8%) patients died. CV composite (11.71 vs. 5.55 events/100 patient-years, P = 0.001) and all-cause mortality rates (5.38 vs. 2.31 events/100 patient-years, P = 0.016) were significantly higher in patients with TSAT ≤20% compared to those with TSAT 20–40% (reference group). Cox regression analysis revealed that patients with TSAT ≤20% had 1.62- and 2.19-fold higher risks for CV composite outcome (P = 0.046) and all-cause mortality (P = 0.030). Moreover, TSAT ≤20% was significantly associated with left ventricular hypertrophy [odds ratio (OR) = 1.46], high-sensitivity C-reactive protein ≥3 mg/dL (OR = 2.09), N-terminal pro B-type natriuretic peptide ≥10000 pg/mL (OR = 2.04), and troponin-T≥0.1 ng/mL (OR = 2.02), on logistic regression analysis.ConclusionsLow TSAT was a significant independent risk factor for adverse clinical outcome in incident dialysis patients with anemia, which may be partly attributed to cardiac dysfunction and inflammation.

Factors Associated with Quality Control of Hemodialysis Treatment

Background/Aims: The number of patients with end-stage renal disease in Korea is increasing annually with 63,341 patients in 2011 with 42,596 of these patients undergoing hemodialysis. The purpose of this study was to present a quality control plan for hemodialysis treatment. Methods: We analyzed 616 hemodialysis units in 2010. The difference between hospitals was analyzed by one-way analysis of variance and the Kruskal-Wallis H test. The factors related to outcome indicators were subjected to multiple regression analysis. Results: The average proportion of physicians with a specialty in hemodialysis was 71.3% and the proportion of nurses with > 2 years experience in hemodialysis units was 76.3%. The average number of hemodialysis sessions performed per day by a physician was 23 and that of a nurse was 4.5. The rate of specialist physicians was significantly related to adequate diastolic blood pressure, integrated outcome indicator, and Hb levels (p < 0.05). Hemodialysis sessions performed by a nurse were significantly related to Hb levels of patients and integrated outcome indicator (p < 0.05). The integrated outcome indicator was significantly related to specialist physicians, the number of hemodialysis sessions performed by a nurse, and compliance with a hemodialysis adequacy and water test cycles (p < 0.05). Conclusions: The appropriate rate of specialist physicians and nurses is important for quality control of hemodialysis treatment. Proper facilities and equipment, as well as regular monitoring of the patient’s condition, are also critical. This will require improved indicators and assessment reliability. (Korean J Med 2014;87:439-448)

The impact of low triiodothyronine levels on mortality is mediated by malnutrition and cardiac dysfunction in incident hemodialysis patients

Little is known about the impact of low triiodothyronine (T3) levels on mortality in end-stage renal disease (ESRD) patients starting hemodialysis (HD) and whether this impact is mediated by malnutrition, inflammation, or cardiac dysfunction. A prospective cohort of 471 incident HD patients from 36 dialysis centers within the Clinical Research Center for ESRD in Korea was selected for this study. Based on the median value of T3, patients were divided into 'higher' and 'lower' groups, and all-cause and cardiovascular (CV) mortality rates were compared. In addition, associations between T3 levels and various nutritional, inflammatory, and echocardiographic parameters were determined. Compared with those in the 'higher' T3 group, albumin, cholesterol, and triglyceride levels, lean body mass estimated by creatinine kinetics (LBM-Cr), and normalized protein catabolic rate (nPCR) were significantly lower in patients with 'lower' T3 levels. The 'lower' T3 group also had a higher left ventricular mass index (LVMI) and a lower ejection fraction (EF). Furthermore, correlation analysis revealed significant associations between T3 levels and nutritional and echocardiographic parameters. All-cause and CV mortality rates were significantly higher in patients with 'lower' T3 levels than in the 'higher' T3 group (113.4 vs 18.2 events per 1000 patient-years, P<0.001, and 49.8 vs 9.1 events per 1000 patient-years, P=0.001, respectively). The Kaplan-Meier analysis also showed significantly worse cumulative survival rates in the 'lower' T3 group (P<0.001). In the Cox regression analysis, low T3 was an independent predictor of all-cause mortality even after adjusting for traditional risk factors (hazard ratio=3.76, P=0.021). However, the significant impact of low T3 on all-cause mortality disappeared when LBM-Cr, nPCR, LVMI, or EF were incorporated into the models. Low T3 has an impact on all-cause mortality in incident HD patients, partly via malnutrition and cardiac dysfunction.

Early Referral to a Nephrologist Improved Patient Survival: Prospective Cohort Study for End-Stage Renal Disease in Korea

The timing of referral to a nephrologist may influence the outcome of chronic kidney disease patients, but its impact has not been evaluated thoroughly. The results of a recent study showing an association between early referral and patient survival are still being debated. A total of 1028 patients newly diagnosed as end-stage renal disease (ESRD) from July 2008 to October 2011 were enrolled. Early referral (ER) was defined as patients meeting with a nephrologist more than a year before dialysis and dialysis education were provided, and all others were considered late referral (LR). The relationship of referral pattern with mortality in ESRD patients was explored using a Cox proportional hazards regression models. Time from referral to dialysis was significantly longer in 599 ER patients than in 429 LR patients (62.3±58.9 versus 2.9±3.4 months, P<0.001). Emergency HD using a temporary vascular catheter was required in 485 (47.2%) out of all patients and in 262 (43.7%) of ER compared with 223 (52.0%) of LR (P = 0.009). After 2 years of follow-up, the survival rate in ER was better than that in LR (hazard ratio [HR] 2.38, 95% confidence interval [CI] 1.27–4.45, P = 0.007). In patients with diabetes nephropathy, patient survival was also significantly higher in ER than in LR (HR 4.74, 95% CI 1.73–13.00, P = 0.002). With increasing age, HR also increased. Timely referral to a nephrologist in the predialytic stage is associated with reduced mortality.

Cardiovascular disease in end-stage renal disease

The number of end-stage renal disease (ESRD) patients is progressively growing with more than 60,000 ESRD patients on renal replacement therapy in Korea. The mortality risk in ESRD patients is approximately 10 to 20-fold higher compared to the general population, which is mainly attributed to prevalent cardiovascular disease in these patients. However, the risk factors for cardiovascular disease in ESRD patients are different from the general population, and useful biomarkers for predicting cardiovascular mortality are not completely defined. The nationwide multicenter Clinical Research Center (CRC) for ESRD program was initiated in Korea not only to elucidate the incidence and prevalence of cardiovascular disease in ESRD patients but also to identify potential risk factors including various biomarkers for cardiovascular disease. A prospective cohort of 864 incident hemodialysis patients, from 34 dialysis centers of the CRC for ESRD in Korea, was followed up for 36 months, and the clinical outcome of these patients was reviewed. This article presents the recent data from the CRC for ESRD program, and, in addition, brief reviews on key risk factors and potential biomarkers for cardiovascular disease in ESRD patients.