1.Vitamin D Attenuates Non-Alcoholic Fatty Liver Disease in High-Fat Diet-Induced Obesity Murine Model
Sook In CHUNG ; Lin LIANG ; Heejae HAN ; Kyung Hee PARK ; Jae-Hyun LEE ; Jung-Won PARK
Yonsei Medical Journal 2025;66(2):75-86
Purpose:
Obesity and metabolic syndrome are acknowledged as key factors contributing to the development of non-alcoholic fatty liver disease (NAFLD). Vitamin D (VitD) is a multifaceted secosteroid hormone known for its anti-fibrotic and anti-inflammatory properties, with its deficiency often linked to obesity. Our study aimed to investigate whether VitD supplementation could mitigate the liver pathology associated with NAFLD.
Materials and Methods:
The NAFLD model was developed by subjecting male C57BL/6 mice to a high-fat diet (HFD) for 14 weeks.These mice were supplemented with VitD through intraperitoneal injection at a dosage of 7 μg/kg, administered three times per week for 7 weeks.
Results:
HFD resulted in VitD deficiency, insulin resistance, and increased liver weight. It elevated serum levels of liver aminotransferases and triglyceride, ultimately leading to steatohepatitis with fibrosis. This model exhibited increased levels of transforming growth factor (TGF)-β1, pro-inflammatory cytokines, HNF4α transcription factors, reactive oxygen species (ROS), renin-angiotensin system activity, and epithelial-mesenchymal transitions (EMT) within the liver. Supplementation with VitD resulted in the recovery of liver weight, improvement in histologic features associated with steatohepatitis, and reduction in alanine aminotransferases and triglyceride levels induced by the HFD. Additionally, it mitigated the HFD-induced over-expressions of TGF-β1 and fibrosis-related genes, along with pro-inflammatory cytokines and ROS. Notably, no adverse effect was found due to VitD supplementation in this model.
Conclusion
VitD ameliorates steatohepatitis within obesity-induced NAFLD through its multifaceted pathways. VitD supplementation emerges as a potentially safe, cost-effective, and direct treatment approach for NAFLD patients dealing with obesity or metabolic dysfunction.
2.Development and Application of New Risk-Adjustment Models to Improve the Current Model for Hospital Standardized Mortality Ratio in South Korea
Hyeki PARK ; Ji-Sook CHOI ; Min Sun SHIN ; Soomin KIM ; Hyekyoung KIM ; Nahyeong IM ; Soon Joo PARK ; Donggyo SHIN ; Youngmi SONG ; Yunjung CHO ; Hyunmi JOO ; Hyeryeon HONG ; Yong-Hwa HWANG ; Choon-Seon PARK
Yonsei Medical Journal 2025;66(3):179-186
Purpose:
This study assessed the validity of the hospital standardized mortality ratio (HSMR) risk-adjusted model by comparing models that include clinical information and the current model based on administrative information in South Korea.
Materials and Methods:
The data of 53976 inpatients were analyzed. The current HSMR risk-adjusted model (Model 1) adjusts for sex, age, health coverage, emergency hospitalization status, main diagnosis, surgery status, and Charlson Comorbidity Index (CCI) using administrative data. As candidate variables, among clinical information, the American Society of Anesthesiologists score, Acute Physiology and Chronic Health Evaluation (APACHE) II, Simplified Acute Physiology Score (SAPS) 3, present on admission CCI, and cancer stage were collected. Surgery status, intensive care in the intensive care unit, and CCI were selected as proxy variables among administrative data. In-hospital death was defined as the dependent variable, and a logistic regression analysis was performed. The statistical performance of each model was compared using C-index values.
Results:
There was a strong correlation between variables in the administrative data and those in the medical records. The C-index of the existing model (Model 1) was 0.785; Model 2, which included all clinical data, had a higher C-index of 0.857. In Model 4, in which APACHE II and SAPS 3 were replaced with variables recorded in the administrative data from Model 2, the C-index further increased to 0.863.
Conclusion
The HSMR assessment model improved when clinical data were adjusted. Simultaneously, the validity of the evaluation method could be secured even if some of the clinical information was replaced with the information in the administrative data.
3.Vitamin D Attenuates Non-Alcoholic Fatty Liver Disease in High-Fat Diet-Induced Obesity Murine Model
Sook In CHUNG ; Lin LIANG ; Heejae HAN ; Kyung Hee PARK ; Jae-Hyun LEE ; Jung-Won PARK
Yonsei Medical Journal 2025;66(2):75-86
Purpose:
Obesity and metabolic syndrome are acknowledged as key factors contributing to the development of non-alcoholic fatty liver disease (NAFLD). Vitamin D (VitD) is a multifaceted secosteroid hormone known for its anti-fibrotic and anti-inflammatory properties, with its deficiency often linked to obesity. Our study aimed to investigate whether VitD supplementation could mitigate the liver pathology associated with NAFLD.
Materials and Methods:
The NAFLD model was developed by subjecting male C57BL/6 mice to a high-fat diet (HFD) for 14 weeks.These mice were supplemented with VitD through intraperitoneal injection at a dosage of 7 μg/kg, administered three times per week for 7 weeks.
Results:
HFD resulted in VitD deficiency, insulin resistance, and increased liver weight. It elevated serum levels of liver aminotransferases and triglyceride, ultimately leading to steatohepatitis with fibrosis. This model exhibited increased levels of transforming growth factor (TGF)-β1, pro-inflammatory cytokines, HNF4α transcription factors, reactive oxygen species (ROS), renin-angiotensin system activity, and epithelial-mesenchymal transitions (EMT) within the liver. Supplementation with VitD resulted in the recovery of liver weight, improvement in histologic features associated with steatohepatitis, and reduction in alanine aminotransferases and triglyceride levels induced by the HFD. Additionally, it mitigated the HFD-induced over-expressions of TGF-β1 and fibrosis-related genes, along with pro-inflammatory cytokines and ROS. Notably, no adverse effect was found due to VitD supplementation in this model.
Conclusion
VitD ameliorates steatohepatitis within obesity-induced NAFLD through its multifaceted pathways. VitD supplementation emerges as a potentially safe, cost-effective, and direct treatment approach for NAFLD patients dealing with obesity or metabolic dysfunction.
4.Development and Application of New Risk-Adjustment Models to Improve the Current Model for Hospital Standardized Mortality Ratio in South Korea
Hyeki PARK ; Ji-Sook CHOI ; Min Sun SHIN ; Soomin KIM ; Hyekyoung KIM ; Nahyeong IM ; Soon Joo PARK ; Donggyo SHIN ; Youngmi SONG ; Yunjung CHO ; Hyunmi JOO ; Hyeryeon HONG ; Yong-Hwa HWANG ; Choon-Seon PARK
Yonsei Medical Journal 2025;66(3):179-186
Purpose:
This study assessed the validity of the hospital standardized mortality ratio (HSMR) risk-adjusted model by comparing models that include clinical information and the current model based on administrative information in South Korea.
Materials and Methods:
The data of 53976 inpatients were analyzed. The current HSMR risk-adjusted model (Model 1) adjusts for sex, age, health coverage, emergency hospitalization status, main diagnosis, surgery status, and Charlson Comorbidity Index (CCI) using administrative data. As candidate variables, among clinical information, the American Society of Anesthesiologists score, Acute Physiology and Chronic Health Evaluation (APACHE) II, Simplified Acute Physiology Score (SAPS) 3, present on admission CCI, and cancer stage were collected. Surgery status, intensive care in the intensive care unit, and CCI were selected as proxy variables among administrative data. In-hospital death was defined as the dependent variable, and a logistic regression analysis was performed. The statistical performance of each model was compared using C-index values.
Results:
There was a strong correlation between variables in the administrative data and those in the medical records. The C-index of the existing model (Model 1) was 0.785; Model 2, which included all clinical data, had a higher C-index of 0.857. In Model 4, in which APACHE II and SAPS 3 were replaced with variables recorded in the administrative data from Model 2, the C-index further increased to 0.863.
Conclusion
The HSMR assessment model improved when clinical data were adjusted. Simultaneously, the validity of the evaluation method could be secured even if some of the clinical information was replaced with the information in the administrative data.
5.Safety and Efficacy of Pivot-Balloon for Severe Tricuspid Regurgitation:The First-in-Man Experiences
Eun Kyoung KIM ; Min-Ku CHON ; Hyun-Sook KIM ; Yong-Hyun PARK ; Sang-Hyun LEE ; Ki Seok CHOO ; Hyung Gon JE ; Dae-Hee KIM ; Tae Oh KIM ; Yoon Seok KOH ; Jae-Hyeong PARK ; Jae-Hwan LEE ; Young Jin CHOI ; Eun Seok SHIN ; Hyuck-Jun YOON ; Seung-Whan LEE ; Joo-Yong HAHN
Korean Circulation Journal 2025;55(1):20-31
Background and Objectives:
Among various emerging catheter-based treatments for severe tricuspid regurgitation (TR), the spacer device can reduce the regurgitation orifice without manipulating the valve leaflet. However, its clinical application has been hampered by traumatic anchoring to the myocardium and the coaxial alignment of the balloon resulting in insufficient TR reduction. This study aimed to evaluate the early-stage safety, technical feasibility, and preliminary efficacy of the novel atraumatic vertical spacer in patients with isolated severe TR.
Methods:
All procedures were guided by fluoroscopy and transthoracic echocardiography.The maximum device placement time with an inflated balloon was 24 hours. Changes in the amount of TR, right ventricular function, and patient hemodynamics were measured during balloon deployment.
Results:
A total of 7 patients (median age 74), underwent successful device implantation without procedure-related complications. During balloon inflation (median 25 minutes), there were no symptoms or signs indicative of TR intolerance. TR was reduced by 1 grade or greater in all patients, with 2 patients exhibiting a reduction of 3 grades, from torrential TR to a moderate degree. Mild TR after balloon inflation was achieved in 3 patients with baseline severe TR. The TR reduction observed during initial balloon deployment was sustained during the subsequent balloon maintenance period.
Conclusions
The Pivot-balloon procedure was safe, technically feasible, and effective in reducing TR in patients with severe TR. No periprocedural complications or adverse cardiovascular events were reported during device placement with TR reduction observed in all patients. However, longer-term follow-up is needed to confirm safety and treatment effect.
6.Fasting is not always good: perioperative fasting leads to pronounced ketone body production in patients treated with SGLT2 inhibitors: a case report
Jae Chan CHOI ; Yo Nam JANG ; Jong Hoon LEE ; Sang Wook PARK ; Jeong A PARK ; Hye Sook KIM ; Jae Won CHOI ; Joo Hyung LEE ; Yong Jae LEE
Korean Journal of Family Medicine 2025;46(3):204-209
Ketone bodies produced by sodium-glucose cotransporter 2 (SGLT2) inhibitors can be advantageous, providing an efficient and stable energy source for the brain and muscles. However, in patients with diabetes, ketogenesis induced by SGLT2 inhibitors may be harmful, potentially resulting in severe diabetic ketoacidosis (DKA). During fasting, ketone body production serves as an alternative and efficient energy source for the brain by utilizing stored fat, promoting mental clarity, and reducing dependence on glucose. The concurrent use of SGLT2 inhibitors during perioperative fasting may further elevate the risk of euglycemic DKA. We describe a case of DKA that occurred during perioperative fasting in a patient receiving empagliflozin, an SGLT2 inhibitor. This case underscores the importance of recognizing the potential risk of DKA in patients with diabetes using SGLT2 inhibitors during perioperative fasting.
7.Paeoniflorin Protects Retinal Pigment Epithelial Cells from High Glucose-Induced Oxidative Damage by Activating Nrf2-Mediated HO-1 Signaling
Cheol PARK ; Hee-Jae CHA ; Su Hyun HONG ; Jeong Sook NOH ; Sang Hoon HONG ; Gi Young KIM ; Jung-Hyun SHIM ; Jin Won HYUN ; Yung Hyun CHOI
Biomolecules & Therapeutics 2025;33(3):518-528
Oxidative stress due to hyperglycemia damages the functions of retinal pigment epithelial (RPE) cells and is a major risk factor for diabetic retinopathy (DR). Paeoniflorin is a monoterpenoid glycoside found in the roots of Paeonia lactiflora Pall and has been reported to have a variety of health benefits. However, the mechanisms underlying its therapeutic effects on high glucose (HG)-induced oxidative damage in RPE cells are not fully understood. In this study, we investigated the protective effect of paeoniflorin against HG-induced oxidative damage in cultured human RPE ARPE-19 cells, an in vitro model of hyperglycemia. Pretreatment with paeoniflorin markedly reduced HG-induced cytotoxicity and DNA damage. Paeoniflorin inhibited HG-induced apoptosis by suppressing activation of the caspase cascade, and this suppression was associated with the blockade of cytochrome c release to cytoplasm by maintaining mitochondrial membrane stability. In addition, paeoniflorin suppressed the HG-induced production of reactive oxygen species (ROS), increased the phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2), a key redox regulator, and the expression of its downstream factor heme oxygenase-1 (HO-1). On the other hand, zinc protoporphyrin (ZnPP), an inhibitor of HO-1, abolished the protective effect of paeoniflorin against ROS production in HG-treated cells. Furthermore, ZnPP reversed the protective effects of paeoniflorin against HG-induced cellular damage and induced mitochondrial damage, DNA injury, and apoptosis in paeoniflorin-treated cells. These results suggest that paeoniflorin protects RPE cells from HG-mediated oxidative stress-induced cytotoxicity by activating Nrf2/HO-1 signaling and highlight the potential therapeutic use of paeoniflorin to improve the symptoms of DR.
8.Role of HIF-1α in the Responses of Tumors to Radiotherapy and Chemotherapy
Chang W SONG ; Hyunkyung KIM ; Mi-Sook KIM ; Heon J PARK ; Sun-Ha PAEK ; Stephanie TEREZAKIS ; L Chinsoo CHO
Cancer Research and Treatment 2025;57(1):1-10
Tumor microenvironment is intrinsically hypoxic with abundant hypoxia-inducible factors-1α (HIF-1α), a primary regulator of the cellular response to hypoxia and various stresses imposed on the tumor cells. HIF-1α increases radioresistance and chemoresistance by reducing DNA damage, increasing repair of DNA damage, enhancing glycolysis that increases antioxidant capacity of tumors cells, and promoting angiogenesis. In addition, HIF-1α markedly enhances drug efflux, leading to multidrug resistance. Radiotherapy and certain chemotherapy drugs evoke profound anti-tumor immunity by inducing immunologic cell death that release tumor-associated antigens together with numerous pro-immunological factors, leading to priming of cytotoxic CD8+ T cells and enhancing the cytotoxicity of macrophages and natural killer cells. Radiotherapy and chemotherapy of tumors significantly increase HIF-1α activity in tumor cells. Unfortunately, HIF-1α effectively promotes various immune suppressive pathways including secretion of immune suppressive cytokines, activation of myeloid-derived suppressor cells, activation of regulatory T cells, inhibition of T cells priming and activity, and upregulation of immune checkpoints. Consequently, the anti-tumor immunity elevated by radiotherapy and chemotherapy is counterbalanced or masked by the potent immune suppression promoted by HIF-1α. Effective inhibition of HIF-1α may significantly increase the efficacy of radiotherapy and chemotherapy by increasing radiosensitivity and chemosensitivity of tumor cells and also by upregulating anti-tumor immunity.
9.Changes in Candidemia during the COVID-19 Pandemic: Species Distribution, Antifungal Susceptibility, Initial Antifungal Usage, and Mortality Trends in Two Korean Tertiary Care Hospitals
Ahrang LEE ; Minji KIM ; Sarah KIM ; Hae Seong JEONG ; Sung Un SHIN ; David CHO ; Doyoung HAN ; Uh Jin KIM ; Jung Ho YANG ; Seong Eun KIM ; Kyung-Hwa PARK ; Sook-In JUNG ; Seung Ji KANG
Chonnam Medical Journal 2025;61(1):52-58
This study aimed to investigate changes in candidemia incidence, species distribution, antifungal susceptibility, initial antifungal use, and mortality trends in Korea before and during the COVID-19 pandemic. A retrospective analysis was conducted on candidemia cases from two tertiary care hospitals in Korea between 2017 and 2022. Data were compared between the pre-pandemic (2017-2019) and pandemic (2020-2022) periods. Statistical methods included incidence rate ratios (IRRs) and multivariate Cox regression to assess 30-day mortality risk factors. A total of 470 candidemia cases were identified, with 48.7% occurring pre-pandemic and 51.3% during the pandemic. While the overall incidence of candidemia remained similar across the two periods (IRR 1.15;p=0.13), the incidence in intensive care units (ICUs) significantly increased during the pandemic (IRR 1.50; p<0.01). The distribution of Candida species did not differ significantly between the two periods. Fluconazole non-susceptibility in C. albicans markedly decreased (10.0% vs. 0.9%, p<0.01), whereas C. glabrata exhibited a significant rise in caspofungin non-susceptibility during the pandemic (0% vs. 22.4%, p<0.01).Echinocandin use increased (21.8% vs. 34.4%; p<0.01), while fluconazole use declined (48.0% vs. 32.8%; p<0.01). Although the 30-day mortality rate was higher during the pandemic (60.2% vs. 57.2%), the difference was not statistically significant (p=0.57).The findings highlight the need for region-specific surveillance and tailored management strategies to improve candidemia outcomes, especially during healthcare disruptions like the COVID-19 pandemic.
10.Effect of Helicobacter pylori Eradication on Metabolic Parameters and Body Composition including Skeletal Muscle Mass: A Matched Case-Control Study
Suh Eun BAE ; Kee Don CHOI ; Jaewon CHOE ; Min Jung LEE ; Seonok KIM ; Ji Young CHOI ; Hana PARK ; Jaeil KIM ; Hye Won PARK ; Hye-Sook CHANG ; Hee Kyong NA ; Ji Yong AHN ; Kee Wook JUNG ; Jeong Hoon LEE ; Do Hoon KIM ; Ho June SONG ; Gin Hyug LEE ; Hwoon-Yong JUNG
Gut and Liver 2025;19(3):346-354
Background/Aims:
Findings on the impact of Helicobacter pylori eradication on metabolic parameters are inconsistent. This study aimed to evaluate the effects of H. pylori eradication on metabolic parameters and body composition, including body fat mass and skeletal muscle mass.
Methods:
We retrospectively reviewed the data of asymptomatic patients who underwent health screenings, including bioelectrical impedance analysis, before and after H. pylori eradication between 2005 and 2021. After matching individuals based on key factors, we compared lipid profiles, metabolic parameters, and body composition between 823 patients from the eradicated group and 823 patients from the non-eradicated groups.
Results:
Blood pressure, erythrocyte sedimentation rate, and glycated hemoglobin values were significantly lower in the eradicated group than in the non-eradicated group. However, changes in body mass index (BMI), body fat mass, appendicular skeletal muscle mass (ASM), waist circumference, and lipid profiles were not significantly different between the two groups. In a subgroup analysis of individuals aged >45 years, blood pressure, erythrocyte sedimentation rate, and glycated hemoglobin changes were significantly lower in the eradicated group than in the noneradicated group. BMI values were significantly higher in the eradicated group than in the noneradicated group; however, no significant differences were observed between the two groups regarding changes in body weight, body fat mass, ASM, or waist circumference. Total cholesterol and low-density lipoprotein cholesterol levels were significantly lower in the eradicated group than in non-eradicated group.
Conclusions
H. pylori eradication significantly reduced blood pressure, glucose levels, and systemic inflammation and improved lipid profiles in patients aged >45 years. BMI, body fat mass, ASM, and waist circumference did not significantly differ between patients in the eradicated group and those in the non-eradicated group.

Result Analysis
Print
Save
E-mail