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: Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort. Methods: Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model. Results: In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7. Conclusion Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Background: Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort. Methods: Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model. Results: In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7. Conclusion Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.

Background: Atrial fibrillation (AF) is associated with increased risks of adverse events including stroke and all-cause death. Understanding the pattern of causes of death (COD) with the relative risks in patients with AF compared to the non-AF population is essential in planning optimal care for patients with AF. We aimed to analyze the COD and its relative risks in patients with AF, using a nationwide population-based cohort. Methods: Using the Korean nationwide claims database, people aged 40 or older who received health examinations in 2009 were included if they had no missing values (n = 6,877,929).In total the study included 40,585 people with AF and 6,837,344 without AF. COD was defined by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnostic codes. Comparison between the AF and non-AF groups was performed with Multivariate Cox proportional regression model. Results: In the AF group, cardiovascular diseases were the most common COD, causing 39.8% of all deaths, compared with 19.0% for non-AF subjects. The AF group was associated with a higher risk of death from cardiovascular and cerebrovascular diseases by almost 3-fold than the matched non-AF group (hazard ratios [HR], 3.082; 95% confidence intervals [CIs], 2.963–3.205 for cardiovascular diseases; HR, 2.981; 95% CI, 2.799–3.175 for cerebrovascular diseases, all P < 0.001). Among patients with AF, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2 -VASc scores. The risk of cerebrovascular death was 11 times higher among patients with a CHA2DS2 -VASc score ≥ 7. Conclusion Compared to non-AF individuals, patients with AF had a higher risk of death from cardiovascular and cerebrovascular diseases, and the mortality risks were wellstratified by the CHA2DS2 -VASc score. Integrated care management of cardiovascular and cerebrovascular diseases for patients with AF might help mitigate mortality.

Rare endocrine diseases are complex conditions that require lifelong specialized care due to their chronic nature and associated long-term complications. In Korea, a lack of nationwide data on clinical practice and outcomes has limited progress in patient care. Therefore, the Multicenter Networks for Ideal Outcomes of Pediatric Rare Endocrine and Metabolic Disease (OUTSPREAD) study was initiated. This study involves 30 centers across Korea. The study aims to improve the long-term prognosis of Korean patients with rare endocrine diseases by collecting comprehensive clinical data, biospecimens, and patient-reported outcomes to identify complications and unmet needs in patient care. Patients with childhood-onset pituitary, adrenal, or gonadal disorders, such as craniopharyngioma, congenital adrenal hyperplasia (CAH), and Turner syndrome were prioritized. The planned enrollment is 1,300 patients during the first study phase (2022–2024). Clinical, biochemical, and imaging data from diagnosis, treatment, and follow-up during 1980–2023 were retrospectively reviewed. For patients who agreed to participate in the prospective cohort, clinical data and biospecimens will be prospectively collected to discover ideal biomarkers that predict the effectiveness of disease control measures and prognosis. Patient-reported outcomes, including quality of life and depression scales, will be evaluated to assess psychosocial outcomes. Additionally, a substudy on CAH patients will develop a steroid hormone profiling method using liquid chromatography-tandem mass spectrometry to improve diagnosis and monitoring of treatment outcomes. This study will address unmet clinical needs by discovering ideal biomarkers, introducing evidence-based treatment guidelines, and ultimately improving long-term outcomes in the areas of rare endocrine and metabolic diseases.