Il Young Kim

Erythropoiesis-stimulating agent (ESA) hyporesponsiveness is a major challenge in the management of anemia in chronic kidney disease (CKD). This study evaluated the association between serum 1,25-dihydroxyvitamin D [1,25(OH)₂D] levels and ESA responsiveness in patients with pre-dialysis CKD. This retrospective cohort study included 363 adult patients with anemia and pre-dialysis CKD who received continuous erythropoietin receptor activator therapy for at least three months. ESA responsiveness was assessed using the erythropoietin resistance index (ERI). The highest ERI tertile was used to define ERI-based relative ESA hyporesponsiveness. Among 363 patients, 121 (33.3%) were classified as having relative ESA hyporesponsiveness. Serum 1,25(OH)₂D levels were significantly lower in the relative ESA-hyporesponsive group. In multivariable analyses, lower serum 1,25(OH)₂D levels were independently associated with relative ESA hyporesponsiveness and higher log-transformed ERI. Exploratory ROC analysis showed modest discriminative ability for identifying patients in the highest ERI tertile. Lower serum 1,25(OH)₂D levels were independently associated with ERI-based relative ESA hyporesponsiveness in pre-dialysis CKD. These findings suggest that active vitamin D status may be linked to ESA responsiveness, as assessed by ERI.

Kyu Won Jang, Byung Hyun Choi, Il Young Kim. Clin Transplant Res -0001;0:. https://doi.org/10.4285/ctr.26.0014

Background and Objectives: Chronic kidney disease (CKD) increases the risk of coronary artery disease (CAD), and vitamin D deficiency—particularly reduced levels of 1,25-dihydroxyvitamin D [1,25(OH)₂D], the biologically active form of vitamin D that declines early in CKD due to impaired renal conversion—may be a contributing factor. This study aimed to assess the relationship between 1,25(OH)₂D levels and the presence and severity of CAD in CKD patients. Materials and Methods: We retrospectively analyzed 398 non-dialysis CKD patients (eGFR < 60 mL/min/1.73 m²) who underwent elective coronary angiography. Serum 1,25(OH)₂D and 25(OH)D levels were measured, and CAD severity was assessed using the Gensini score. Results: Lower 1,25(OH)₂D levels were independently associated with both the presence and se-verity of CAD. Logistic regression revealed that each 1 pg/mL increase in 1,25(OH)₂D was linked to an 11% reduction in odds of significant CAD (OR: 0.89; 95% CI: 0.86–0.93; p < 0.001). In contrast, 25(OH)D was not significantly related to CAD. Linear regression showed an inverse correlation between 1,25(OH)₂D and Gensini scores (β = −0.329, p < 0.001), indicating reduced disease severity with higher vitamin D levels. Subgroup analyses confirmed consistent associations across age, sex, diabetes, hypertension, and LDL-cholesterol categories. ROC analysis demonstrated that 1,25(OH)₂D alone had good predictive ability for CAD (AUC = 0.818), which improved to 0.925 when combined with traditional risk factors. The optimal cutoff for 1,25(OH)₂D was ≤16.6 pg/mL, yielding 73.3% sensitivity and 83.5% specificity. Conclusions: Serum 1,25(OH)₂D is an independent predictor of both the presence and extent of CAD in CKD patients and may serve as a valuable non-traditional biomarker for cardiovascular risk assessment.

Kim IY. Electrolyte Blood Press. 2026 ;24:e7. https://doi.org/10.5049/EBP.2026.24.e7

Background: Obesity is a major worldwide health problem and can be related to cellular senescence. Along with the rise in obesity, the comorbidity of renal ischemia-reperfusion (IR) injury is increasing. Whether obesity accelerates the severity of IR injury and whether senescence contributes to these conditions remain unclear. We studied the degree of injury and cellular senescence in the IR kidneys and perirenal adipose tissues of high-fat-diet–induced obese mice. Methods: C57BL/6 mice fed standard chow or a high-fat diet for 16 weeks were randomized to renal IR or sham group (n = 6–10 each). Renal IR was performed by unilateral clamping of the right renal pedicle for 30 minutes. Six weeks after surgery, renal function, perirenal fat/renal senescence, and histology were evaluated ex vivo.Results: Obese mice showed more renal tubular damage and fibrosis in IR injury than control mice, even though the degree of ischemic insult was comparable. Renal expression of senescence and its secretory phenotype was upregulated in either IR injury or with a high-fat diet and was further increased in the IR kidneys of obese mice. Fat senescence and the expression of tumor necrosis factor alpha were also increased, especially in the perirenal depot of the IR kidneys, with a high-fat diet.Conclusion: A high-fat diet aggravates IR injury in murine kidneys, which is associated, at least in part, with perirenal fat senescence and inflammation. These observations support the exploration of therapeutic targets of the adipo-renal axis in injured obese kidneys.

Fabry disease (FD) is a lysosomal storage disorder caused by pathogenic variants in the gene encoding alpha-galactosidase A (GLA). Deficiency of GLA results in the progressive accumulation of glycosphingolipids in virtually all organs, resulting in a progressive multisystem disease. Due to multi-organ involvement in FD, a comprehensive, multidisciplinary approach to diagnosis and treatment with regular follow-ups is essential. The Pusan National University Yangsan Hospital (PNUYH) multidisciplinary care model of FD aims to provide detailed practice guidelines and evidence-based recommendations for the diagnosis, screening, and treatment of FD according to specialty. This guideline focuses on the “quarterback” type of multidisciplinary team (MDT) operation and is limited in its applicability to the Korean insurance system. However, it reflects our team’s extensive experience and insights into optimizing MDT operations within these constraints and is expected to be highly beneficial for centers initiating MDTs for the effective treatment of FD.

Background: Sarcopenia upon admission to the intensive care unit (ICU) consistently correlates with adverse outcomes, including heightened mortality, in critically ill patients. This study aims to investigate the independent association of sarcopenia with both mortality and recovery from dialysis in critically ill patients with sepsis-induced acute kidney injury (SIAKI) undergoing continuous renal replacement therapy (CRRT). Methods: This retrospective study included 618 patients with SIAKI who underwent CRRT in our ICU. All patients had abdominal computed tomography (CT) scans within 3 days preceding ICU admission. The cross-sectional area of skeletal muscles at the third lumbar vertebra was quantified, and the skeletal muscle index (SMI), a normalized measure of skeletal muscle mass, was computed. Using Korean-specific SMI cutoffs, patients were categorized into sarcopenic and non-sarcopenic groups. Results: Among the 618 patients, 301 expired within 28 days of ICU admission. Multivariable Cox regression analysis revealed that sarcopenia independently predicted 28-day mortality. Among survivors, sarcopenia was independently associated with recovery from dialysis within 28 days after ICU admission. Kaplan-Meier analysis illustrated that sarcopenic patients had a higher mortality rate and a lower rate of recovery from dialysis within 28 days after ICU admission compared to non-sarcopenic patients. Conclusion: This study underscores the independent association of sarcopenia, assessed via CT-derived SMI, with both mortality and recovery from dialysis in critically ill patients with SIAKI undergoing CRRT. The inclusion of sarcopenia assessment could serve as a valuable tool for physicians in effectively stratifying the risk of adverse outcomes in these patients.

Background: Acute kidney injury (AKI) is prevalent in critically ill patients and is associated with an increased risk of in-hospital mortality. Nephrology consultation may be protective, but this has rarely been evaluated in South Korea. Methods: This multicenter retrospective study was based on the electronic medical records (EMRs) of two third-affiliated hospitals. We extracted the records of patients admitted to intensive care units (ICUs) between 2011 and 2020, and retrospectively detected AKI using the modified serum creatinine criteria of the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. The AKI diagnosis date was defined as the first day of a significant change in serum creatinine level (≥0.3 mg/dL) within 48 hours. Nephrology consultation status was retrieved from the EMRs. Results: In total, 2,461 AKI patients were included; the median age was 65 years (interquartile range [IQR], 56–75 years), 1,459 (59.3%) were male, and 1,065 (43.3%) were of AKI stage 3. During a median of 5 days (IQR, 3–11 days) of ICU admission, nephrology consultations were provided to 512 patients (20.8%). Patients who received such consultations were older, had more comorbidities, and more commonly required dialysis. In a multivariable model, nephrology consultation reduced the risk of in-hospital mortality by 30% (hazard ratio, 0.71; 95% confidence interval, 0.57–0.88). Other factors significant for in-hospital mortality were older age, a higher sequential organ failure assessment (SOFA) score, sepsis, diabetes, hypertension, heart disease, and cancer. Conclusion: For AKI patients in ICUs, nephrology consultation reduced the risk of in-hospital mortality, particularly among those with multiple comorbidities. Therefore, nephrology consultation should not be omitted during ICU care.