Background: With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality. Methods: We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis. Results: Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality. Conclusion We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.

Background: Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly. Methods: We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease. Results: During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001). Conclusion In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.

Early mortality following hemodialysis initiation hinders survival improvement in older patients. This study aimed to develop a clinical risk model for predicting 6-month mortality after dialysis initiation in older Korean hemodialysis patients. Methods: We analyzed data from incident hemodialysis patients aged >70 years from the Korean Society of Geriatric Nephrology (KSGN) database. A prediction model was developed using multivariate logistic regression analysis and externally validated with independent datasets. Results: Among 1,751 incident hemodialysis patients, the 6-month mortality rate was 15.5%. Using multivariate logistic analysis, we constructed the KSGN score as an independent risk factor for 6-month mortality, and its components and score are as follows: old age at dialysis initiation (≥85 years, score 2); hypertension and renovascular disease as a primary etiology of end-stage kidney disease (ESKD) (score 1); malignancy history (yes, score 1); low serum albumin (<3.5 g/dL, score 1); hypertension treatment (yes, score –1); prepared vascular access on maintenance dialysis (arteriovenous fistula/arteriovenous graft, score –3). In the development cohort, the area under the curve (AUC) for the KSGN score was significantly higher than the Alberta Wick’s score (0.707 vs. 0.683, p = 0.001). In the validation cohort, the KSGN score’s performance was comparable to existing models. Conclusion: The KSGN score may be a valuable tool for predicting early mortality after dialysis initiation in older patients with ESKD, aiding in decision-making and management regarding dialysis initiation.

The prevalence of dementia is 2- to 7-fold higher among patients with end-stage kidney disease (ESKD) than among the general population; however, its clinical implications in this population remain unclear. Therefore, this study aimed to determine whether comorbid dementia increases mortality among older patients with ESKD undergoing newly initiated hemodialysis. Methods: We analyzed data from the Korean Society of Geriatric Nephrology retrospective cohort, which included 2,736 older ESKD patients (≥70 years old) who started hemodialysis between 2010 and 2017. Kaplan-Meier survival and Cox regression analyses were used to examine all-cause mortality between the patients with and without dementia in this cohort. Results: Of the 2,406 included patients, 8.3% had dementia at the initiation of dialysis; these patients were older (79.6 ± 6.0 years) than patients without dementia (77.7 ± 5.5 years) and included more women (male:female, 89:111). Pre-ESKD diagnosis of dementia was associated with an increased risk of overall mortality (hazard ratio, 1.503; p < 0.001), and this association remained consistent after multivariate adjustment (hazard ratio, 1.268; p = 0.009). In subgroup analysis, prevalent dementia was associated with mortality following dialysis initiation in female patients, those aged <85 years, those with no history of cerebrovascular accidents or severe behavioral disorders, those not residing in nursing facilities, and those with no or short-term hospitalization. Conclusion: A pre-ESKD diagnosis of dementia is associated with mortality following dialysis initiation in older Korean population. In older patients with ESKD, cognitive assessment at dialysis initiation is necessary.

Background: The aim of this study is to investigate the specific pathway involved in human leukocyte antigen (HLA) sensitization using single-cell RNA-sequencing analysis and an allo-sensitized mouse model developed with an HLA.A2 transgenic mouse. Methods: For sensitization, wild-type C57BL/6 mouse received two skin grafts from C57BL/6-Tg(HLA-A2.1)1Enge/J mouse (allogeneic mouse, ALLO). For syngeneic control (SYN), skin grafts were transferred from C57BL/6 to C57BL/6. We performed single-cell RNA-sequencing analysis on splenocytes isolated from ALLO and SYN and compared the gene expression between them. Results: We generated 9,190 and 8,890 single-cell transcriptomes from ALLO and SYN, respectively. Five major cell types (B cells, T cells, natural killer cells, macrophages, and neutrophils) and their transcriptome data were annotated according to the representative differentially expressed genes of each cell cluster. The percentage of B cells was higher in ALLO than it was in SYN. Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that the highly expressed genes in the B cells from ALLO were mainly associated with antigen processing and presentation pathways, allograft rejection, and the Th17 cell differentiation pathway. Upregulated genes in the T cells of ALLO were involved in the interleukin (IL)-17 signaling pathway. The ratio of Th17 cluster and Treg cluster was increased in the ALLO. On flow cytometry, the percentage of Th17 (IL-17+/CD4+ T) cells was higher and regulatory T cells (FOXP3+/CD4+ T) was lower in the ALLO compared to those in the SYN. Conclusion Our results indicate that not only the B cell lineage but also the Th17 cells and their cytokine (IL-17) are involved in the sensitization to HLA.

Background: Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known. Methods: From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation–Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups. Results: Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence inter val [CI], 0.55– 0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% 0.56–0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79–1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65–2.17; P = 0.582). Conclusion In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.

We assessed the risk factors for major amputation of diabetic foot ulcers (DFUs) in patients with diabetic kidney disease (DKD) stages 3b–5. For DFU assessment, in addition to DFU location and presence of infection, ischemia, and neuropathy, vascular calcification was assessed using the medial arterial calcification (MAC) score. Of 210 patients, 26 (12.4%) underwent major amputations. Only the location and extension of DFU, represented by Texas grade differed between the minor and major amputation groups. However, after adjusting for covariates, ulcer location of mid- or hindfoot (vs. forefoot, odds ratio [OR] = 3.27), Texas grades 2 or 3 (vs. grade 0, OR = 5.78), and severe MAC (vs. no MAC, OR = 4.46) was an independent risk factor for major amputation (all P < 0.05). The current use of antiplatelets was a possible protective factor for major amputations (OR = 0.37, P = 0.055). In conclusion, DFU with severe MAC is associated with major amputation in patients with DKD.

Generally, an induction agent is chosen based on the conditions of the deceased donor and the recipient. Antithymocyte globulin (ATG) is preferred in relatively high-risk conditions. No clear evidence indicates which induction agent is safer or more efficient for deceased donor kidney transplantation (DDKT). This study compares the efficacy and safety of basiliximab (BSX) and ATG according to donor characteristics in DDKT. Methods: A total of 724 kidney transplant recipients from three transplant centers were enrolled, and propensity score matching was performed. Based on a donor age of 60 years, donor kidney with acute kidney injury (AKI), and Kidney Donor Profile Index (KDPI) score of 65%, we investigated how the choice of induction therapy agent affected the posttransplant clinical outcomes of delayed graft function (DGF), acute rejection (AR), infectious complications, and allograft and patient survival. Results: AR and DGF did not differ significantly according to induction agent in elderly/young donor, AKIon-AKI, and high-KDPI/ low-KDPI subgroups. The infection rate did not show meaningful differences. The differences in death-censored allograft survival and patient survival rates between induction agents were not statistically significant. Conclusion: Our study suggests that BSX can produce clinical outcomes similarly favorable to those of ATG even in DDKT cases with relatively poor donor conditions. Nonetheless, the donor and recipient conditions, immunological risk, and infection risk must be all taken into consideration when choosing an induction agent. Therefore, clinicians should carefully select the induction therapy agent for DDKT based on the risks and benefits in each DDKT case.

Evidence of the ethical appropriateness and clinical benefits of shared decision-making (SDM) are accumulating. This study aimed to not only identify physicians’ perspectives on SDM, and practices related to end-of-life care in particular, but also to gauge the effect of SDM education on physicians in Korea. Methods: A 14-item questionnaire survey using a modified Delphi process was delivered to nephrologists and internal medicine trainees at 17 university hospitals. Results: A total of 309 physicians completed the survey. Although respondents reported that 69.9% of their practical decisions were made using SDM, 59.9% reported that it is not being applied appropriately. Only 12.3% of respondents had received education on SDM as part of their training. The main obstacles to appropriate SDM were identified as lack of time (46.0%), educational materials and tools (29.4%), and education on SDM (24.3%). Although only a few respondents had received training on SDM, the proportion of those who thought they were using SDM appropriately in actual practice was high; the proportion of those who chose lack of time and education as factors that hindered the proper application of SDM was low. Conclusion: The majority of respondents believed that SDM was not being implemented properly in Korea, despite its use in actual practice. To improve the effectiveness of SDM in the Korean medical system, appropriate training programs and supplemental policies that guarantee sufficient application time are required.