The Korean Society of Nephrology (KSN) has maintained a nationwide end-stage renal disease (ESRD) registry data from Korean Renal Data System (KORDS) since 1985, as the representative registry of ESRD patients in Korea. This review is aimed to update the status of domestic ESRD and to provide evidence on the direction of dialysis therapy. The KORDS Committee of KSN has collected data on dialysis centers and patients through an online registry program, and the data from 1986 to 2019 were analyzed. The incidence and prevalence of ESRD patients in Korea are increasing. The ESRD population numbered more than 100,000 in 2019, doubling during the 10 years since 2010. The proportion of diabetes mellitus as a major cause of ESRD seems to have reached a plateau. The increasing number of elderly dialysis patients is a constant trend, with more than half for the proportion of patients older than 65 years old in 2019. All-cause mortality decreased for the last approximately 20 years, regardless of sex, age, and cause of ESRD. The 5-year patient survival rate in both hemodialysis and peritoneal dialysis increased from 2001 to 2013. Since 2013, the patient survival rates in peritoneal dialysis were similar to those in hemodialysis. Cardiovascular complications were the leading cause of death in ESRD patients. The incidence and prevalence of Korean ESRD patients have increased over time, although patient survival has also steadily increased. The establishment of a surveillance method to address the major cause of mortality in ESRD patients will help improve outcomes.

Background: Copeptin is secreted in equimolar amounts as arginine vasopressin, main hormone regulating body fluid homeostasis. A recent study reported a copeptin-based classification of osmoregulatory defects in syndromes of inappropriate antidiuresis that may aid in prediction of therapeutic success. We investigated usefulness of copeptin for differentiating etiologies of hyponatremia and predicting efficacy and safety of hypertonic saline treatment in hyponatremic patients. Methods: We performed a multicenter, prospective cohort study of 100 inpatients with symptomatic hyponatremia (corrected serum sodium [sNa] <= 125 mmol/L) treated with hypertonic saline. Copeptin levels were measured at baseline and 24 hours after treatment initiation, and patients were classified as being below or above median of copeptin at baseline or at 24 hours, respectively. Correlations between target, under correction, and overcorrection rates of sNa within 24 hours/24-48 hours and copeptin levels at baseline/24 hours were analyzed. Results: Mean sNa and median copeptin levels were 117.9 and 16.9 pmol/L, respectively. Ratio of copeptin-to-urine sodium allowed for an improved differentiation among some (insufficient effective circulatory volume), but not all hyponatremia etiologic subgroups. Patients with below-median copeptin levels at baseline achieved a higher target correction rate in 6/24 hours (odds ratio [OR], 2.97; p = 0.02/OR, 6.21; p = 0.006). Patients with below-median copeptin levels 24 hours after treatment showed a higher overcorrection rate in next 24 hours (OR, 18.00, p = 0.02). Conclusion: There is a limited diagnostic utility of copeptin for differential diagnosis of hyponatremia. However, copeptin might be useful for predicting responses to hypertonic saline treatment in hyponatremic patients.

With an increasing aging population, the mean age of patients with end-stage kidney disease (ESKD) is globally increasing. However, the current clinical status of elderly patients undergoing hemodialysis (HD) is rarely reported in Korea. The current study analyzed the clinical features and trends of older patients undergoing HD from the Korean Renal Data System (KORDS) database. The patients were divided into three groups according to age: <65 years (the young group), n = 50,591 (35.9%); 65–74 years (the younger-old group), n = 37,525 (26.6%); and ≥75 years (the older-old group), n = 52,856 (37.5%). The proportion of older-old group undergoing HD significantly increased in incidence and decreased in prevalence from 2013 to 2022. The median levels of hemoglobin, serum creatinine, albumin, calcium, phosphorus, and intact parathyroid hormone significantly decreased in the older-old group. The proportions of arteriovenous fistula creation and left forearm placement showed decreased trends with age. Although the utilization of low surface area dialyzers increased with age, the dialysis adequacy, including urea reduction ratio and Kt/V was within acceptable range in the older-old group on HD. Over the past 20 years, the mortality rate in the older-old group has increased, with cardiovascular diseases decreasing and infectious diseases increasing. The incidence of elderly patients undergoing HD has increased over time, but the high mortality of the older-old group needs to be solved. Therefore, it is imperative to develop holistic strategies based on age and individual needs for patients with ESKD.

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.

Background: A vascular access blood flow (Qa) to cardiac output (CO) ratio greater than 0.3 increases the risk of high-output heart failure (HOHF). This study analyzed the characteristics and risk factors associated with a high Qa/CO ratio and effective CO (COef) in these patients over one year. Methods: This prospective study enrolled 142 hemodialysis (HD) patients, divided by the Qa/CO ratio. Baseline and one-year hemodynamics were measured: volume by bioimpedance, CO by echocardiography, Qa and brachial flow by transonic and ultrasound. Risk factors for HOHF were analyzed using receiver operating characteristic (ROC) curves and multivariable regression. Results: The study population was 66% male, mean age of 65, with 71% using arteriovenous fistulae (AVF) for vascular access. In the high Qa/CO group, cases of younger ages (62 vs. 67 years, p = 0.040) with upper arm access (73.1% vs. 32.8%, p < 0.001) were more prevalent, and diastolic blood pressure (DBP) was higher (76.8 ± 15.1 vs. 66.7 ± 14.4 mmHg, p = 0.002). Independent risk factors for high Qa/CO were elevated DBP (odds ratio [OR]: 1.080; 95% confidence interval [CI]: 1.028–1.134), upper arm access (OR: 8.113; 95% CI: 1.842–35.741), low resistive index (RI) (OR: 0.000; 95% CI: 0.000–0.417), and COef (OR: 0.164; 95% CI: 0.065–0.416). After one year, the high Qa/CO group showed significant increases in CO and COef (4.82 ± 1.25 L/min vs. 6.16 ± 2.05 L/min, p = 0.007, and 2.84 ± 0.95 L/min to 4.40 ± 1.89 L/min, p = 0.001, respectively). A baseline Qa cutoff value of 1.4 L/min demonstrated high diagnostic efficacy in identifying the high Qa/CO group. Conclusions: High Qa/CO ratios increase overt HOHF risk due to cardiac strain. This study reveals AV access-driven cardiac adaptations in patients with high Qa/CO and low COef, emphasizing the necessity for ongoing clinical and hemodynamic monitoring.