1.Impact of obesity on renal function in elderly Korean adults: a national population-based cohort study
Jihyun YANG ; Hui Seung LEE ; Chi-Yeon LIM ; Hyunsuk KIM ; Sungjin CHUNG ; Soon Hyo KWON ; Jang-Hee CHO ; Kyung Don YOO ; Woo Yeong PARK ; In O SUN ; Byung Chul YU ; Gang-Jee KO ; Jae Won YANG ; Won Min HWANG ; Sang Heon SONG ; Sung Joon SHIN ; Yu Ah HONG ; Eunjin BAE ; Young Youl HYUN
Kidney Research and Clinical Practice 2026;45(1):65-76
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.
2.Factors Associated with Postoperative Recurrence in Stage I to IIIA Non–Small Cell Lung Cancer with Epidermal Growth Factor Receptor Mutation: Analysis of Korean National Population Data
Kyu Yean KIM ; Ho Cheol KIM ; Tae Jung KIM ; Hong Kwan KIM ; Mi Hyung MOON ; Kyongmin Sarah BECK ; Yang Gun SUH ; Chang Hoon SONG ; Jin Seok AHN ; Jeong Eun LEE ; Jae Hyun JEON ; Chi Young JUNG ; Jeong Su CHO ; Yoo Duk CHOI ; Seung Sik HWANG ; Chang Min CHOI ; Seung Hun JANG ; Jeong Uk LIM ;
Cancer Research and Treatment 2025;57(1):83-94
Purpose:
Recent development in perioperative treatment of resectable non–small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection.
Materials and Methods:
Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee.
Results:
A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors.
Conclusion
Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.
3.Factors Associated with Postoperative Recurrence in Stage I to IIIA Non–Small Cell Lung Cancer with Epidermal Growth Factor Receptor Mutation: Analysis of Korean National Population Data
Kyu Yean KIM ; Ho Cheol KIM ; Tae Jung KIM ; Hong Kwan KIM ; Mi Hyung MOON ; Kyongmin Sarah BECK ; Yang Gun SUH ; Chang Hoon SONG ; Jin Seok AHN ; Jeong Eun LEE ; Jae Hyun JEON ; Chi Young JUNG ; Jeong Su CHO ; Yoo Duk CHOI ; Seung Sik HWANG ; Chang Min CHOI ; Seung Hun JANG ; Jeong Uk LIM ;
Cancer Research and Treatment 2025;57(1):83-94
Purpose:
Recent development in perioperative treatment of resectable non–small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection.
Materials and Methods:
Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee.
Results:
A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors.
Conclusion
Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.
4.Factors Associated with Postoperative Recurrence in Stage I to IIIA Non–Small Cell Lung Cancer with Epidermal Growth Factor Receptor Mutation: Analysis of Korean National Population Data
Kyu Yean KIM ; Ho Cheol KIM ; Tae Jung KIM ; Hong Kwan KIM ; Mi Hyung MOON ; Kyongmin Sarah BECK ; Yang Gun SUH ; Chang Hoon SONG ; Jin Seok AHN ; Jeong Eun LEE ; Jae Hyun JEON ; Chi Young JUNG ; Jeong Su CHO ; Yoo Duk CHOI ; Seung Sik HWANG ; Chang Min CHOI ; Seung Hun JANG ; Jeong Uk LIM ;
Cancer Research and Treatment 2025;57(1):83-94
Purpose:
Recent development in perioperative treatment of resectable non–small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection.
Materials and Methods:
Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee.
Results:
A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors.
Conclusion
Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.
5.Prediction model for 6-month mortality in incident older hemodialysis patients in South Korea
Woo Yeong PARK ; Eunjin BAE ; Hui-Seung LEE ; Chi-Yeon LIM ; Jang-Hee CHO ; Byung Chul YU ; Miyeun HAN ; Sang Heon SONG ; Gang-Jee KO ; Jae Won YANG ; Sungjin CHUNG ; Yu Ah HONG ; Young Youl HYUN ; In O SUN ; Hyunsuk KIM ; Won Min HWANG ; Sung Joon SHIN ; Soon Hyo KWON ; Kyung Don YOO ;
Kidney Research and Clinical Practice 2025;44(4):664-678
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.
6.Bonding silica-containing CAD/CAM dental blocks to composite resin with universal adhesives
Chi-Yong PARK ; Minjeong SHIN ; Shin Hye CHUNG ; Young-Seok PARK ; Bum-Soon LIM
Korean Journal of Dental Materials 2024;51(1):63-84
The bond strength to the silicate-based CAD/CAM blocks may be affected by the composition and microstructure of the silicatebased blocks, surface treatment, and the properties of the applied adhesive. In this study, the shear bond strength to the silicate blocks with various universal adhesives after sandblasting or HF-treatment was measured, and the effects of the additional silane application after surface treatments are evaluated. Six silica-containing blocks and five universal adhesives currently used in dental clinics were selected. After polishing the silicate block surface, the specimens were divided into two groups. The first groups were HF-treated and the second groups were sandblasted with alumina, and the surface roughness, contact angle, and microstructure were analyzed by CLSM (Confocal Laser Scanning Microscope), contact angle analyzer, and FE-SEM (Field Emission Scanning Electron Microscope).Composite resin (2 mm diameter) was bonded with universal adhesive to silicate blocks and stored in a 37 ℃ water bath for 24 hours, and the shear bond strength was measured using a universal testing machine. The measured values were statistically analyzed using the Tukey-multiple comparison test (α=0.05). For hybrid composite ceramics, there was no significant difference in bond strength between sandblasting or HF-treatment, and additional silane application may not be necessary when bonding with a universal adhesive, whereas for leucite-reinforced and lithium disilicate glass-ceramics, HF-treatment may be more favorable for adhesion than sandblasting, and additional silane application appears to be necessary even when applying a universal adhesive.
7.Current Understanding on Psilocybin for Major Depressive Disorder: A Review Focusing on Clinical Trials
Sheng-Min WANG ; Sunghwan KIM ; Won-Seok CHOI ; Hyun Kook LIM ; Young Sup WOO ; Chi-Un PAE ; Won-Myong BAHK
Clinical Psychopharmacology and Neuroscience 2024;22(2):222-231
Previous studies suggested effectiveness of psilocybin in the field of mental health. FDA designated psilocybin as a “breakthrough therapy” for the treatment of treatment-resistant depression (TRD) in 2018. This paper provided a review of psilocybin’s potential role in treatment of depression by focusing on published clinical trials. Studies showed that psilocybin, an agonist on 5-HT2A receptors, manifests antidepressant and anxiolytic effects by increasing glutamate transmission, reducing brain inflammation, decreasing default mode network activity. In terms of clinical trials, eleven studies (six open-label and five double blinded randomized clinical trials, DB-RCTs) trials exploring psilocybin’s impact on depression were found. Among open-label studies, a pilot study on TRD patients demonstrated significant reductions in depressive symptoms after two psilocybin sessions. Psilocybin also improved cognitive bias associated with depression. Extension studies confirmed sustained improvements and high remission rates. Among five DB-RCTs, two showed that psilocybin led to significant reductions in anxiety and depression in cancer patients, and the improvements sustained for over 6 months. In MDD, psilocybin showed rapid reductions in depression, with higher remission rates compared to escitalopram in a DB-RCT. Another DB-RCT showed that psilocybin induced higher decrease in depression around 6 hours after their administrations than placebo. The last DB-RCT showed that in patients with TRD, a single dose of psilocybin 25 mg, but not psilocybin 10 mg, resulted in superior antidepressant effect than psilocybin 1 mg. Overall, psilocybin showed promise in treating depression and anxiety, with notable safety profiles. Further research should explore optimal dosages and long-term effects.
8.ChatGPT Predicts In-Hospital All-Cause Mortality for Sepsis: In-Context Learning with the Korean Sepsis Alliance Database
Namkee OH ; Won Chul CHA ; Jun Hyuk SEO ; Seong-Gyu CHOI ; Jong Man KIM ; Chi Ryang CHUNG ; Gee Young SUH ; Su Yeon LEE ; Dong Kyu OH ; Mi Hyeon PARK ; Chae-Man LIM ; Ryoung-Eun KO ;
Healthcare Informatics Research 2024;30(3):266-276
Objectives:
Sepsis is a leading global cause of mortality, and predicting its outcomes is vital for improving patient care. This study explored the capabilities of ChatGPT, a state-of-the-art natural language processing model, in predicting in-hospital mortality for sepsis patients.
Methods:
This study utilized data from the Korean Sepsis Alliance (KSA) database, collected between 2019 and 2021, focusing on adult intensive care unit (ICU) patients and aiming to determine whether ChatGPT could predict all-cause mortality after ICU admission at 7 and 30 days. Structured prompts enabled ChatGPT to engage in in-context learning, with the number of patient examples varying from zero to six. The predictive capabilities of ChatGPT-3.5-turbo and ChatGPT-4 were then compared against a gradient boosting model (GBM) using various performance metrics.
Results:
From the KSA database, 4,786 patients formed the 7-day mortality prediction dataset, of whom 718 died, and 4,025 patients formed the 30-day dataset, with 1,368 deaths. Age and clinical markers (e.g., Sequential Organ Failure Assessment score and lactic acid levels) showed significant differences between survivors and non-survivors in both datasets. For 7-day mortality predictions, the area under the receiver operating characteristic curve (AUROC) was 0.70–0.83 for GPT-4, 0.51–0.70 for GPT-3.5, and 0.79 for GBM. The AUROC for 30-day mortality was 0.51–0.59 for GPT-4, 0.47–0.57 for GPT-3.5, and 0.76 for GBM. Zero-shot predictions using GPT-4 for mortality from ICU admission to day 30 showed AUROCs from the mid-0.60s to 0.75 for GPT-4 and mainly from 0.47 to 0.63 for GPT-3.5.
Conclusions
GPT-4 demonstrated potential in predicting short-term in-hospital mortality, although its performance varied across different evaluation metrics.
9.Risk Factors for the Mortality of Patients With Coronavirus Disease 2019Requiring Extracorporeal Membrane Oxygenation in a Non-Centralized Setting: A Nationwide Study
Tae Wan KIM ; Won-Young KIM ; Sunghoon PARK ; Su Hwan LEE ; Onyu PARK ; Taehwa KIM ; Hye Ju YEO ; Jin Ho JANG ; Woo Hyun CHO ; Jin-Won HUH ; Sang-Min LEE ; Chi Ryang CHUNG ; Jongmin LEE ; Jung Soo KIM ; Sung Yoon LIM ; Ae-Rin BAEK ; Jung-Wan YOO ; Ho Cheol KIM ; Eun Young CHOI ; Chul PARK ; Tae-Ok KIM ; Do Sik MOON ; Song-I LEE ; Jae Young MOON ; Sun Jung KWON ; Gil Myeong SEONG ; Won Jai JUNG ; Moon Seong BAEK ;
Journal of Korean Medical Science 2024;39(8):e75-
Background:
Limited data are available on the mortality rates of patients receiving extracorporeal membrane oxygenation (ECMO) support for coronavirus disease 2019 (COVID-19). We aimed to analyze the relationship between COVID-19 and clinical outcomes for patients receiving ECMO.
Methods:
We retrospectively investigated patients with COVID-19 pneumonia requiring ECMO in 19 hospitals across Korea from January 1, 2020 to August 31, 2021. The primary outcome was the 90-day mortality after ECMO initiation. We performed multivariate analysis using a logistic regression model to estimate the odds ratio (OR) of 90-day mortality. Survival differences were analyzed using the Kaplan–Meier (KM) method.
Results:
Of 127 patients with COVID-19 pneumonia who received ECMO, 70 patients (55.1%) died within 90 days of ECMO initiation. The median age was 64 years, and 63% of patients were male. The incidence of ECMO was increased with age but was decreased after 70 years of age. However, the survival rate was decreased linearly with age. In multivariate analysis, age (OR, 1.048; 95% confidence interval [CI], 1.010–1.089; P = 0.014) and receipt of continuous renal replacement therapy (CRRT) (OR, 3.069; 95% CI, 1.312–7.180; P = 0.010) were significantly associated with an increased risk of 90-day mortality. KM curves showed significant differences in survival between groups according to age (65 years) (log-rank P = 0.021) and receipt of CRRT (log-rank P = 0.004).
Conclusion
Older age and receipt of CRRT were associated with higher mortality rates among patients with COVID-19 who received ECMO.
10.Deep Learning-Based Automatic Classification of Ischemic Stroke Subtype Using Diffusion-Weighted Images
Wi-Sun RYU ; Dawid SCHELLINGERHOUT ; Hoyoun LEE ; Keon-Joo LEE ; Chi Kyung KIM ; Beom Joon KIM ; Jong-Won CHUNG ; Jae-Sung LIM ; Joon-Tae KIM ; Dae-Hyun KIM ; Jae-Kwan CHA ; Leonard SUNWOO ; Dongmin KIM ; Sang-Il SUH ; Oh Young BANG ; Hee-Joon BAE ; Dong-Eog KIM
Journal of Stroke 2024;26(2):300-311
Background:
and Purpose Accurate classification of ischemic stroke subtype is important for effective secondary prevention of stroke. We used diffusion-weighted image (DWI) and atrial fibrillation (AF) data to train a deep learning algorithm to classify stroke subtype.
Methods:
Model development was done in 2,988 patients with ischemic stroke from three centers by using U-net for infarct segmentation and EfficientNetV2 for subtype classification. Experienced neurologists (n=5) determined subtypes for external test datasets, while establishing a consensus for clinical trial datasets. Automatically segmented infarcts were fed into the model (DWI-only algorithm). Subsequently, another model was trained, with AF included as a categorical variable (DWI+AF algorithm). These models were tested: (1) internally against the opinion of the labeling experts, (2) against fresh external DWI data, and (3) against clinical trial dataset.
Results:
In the training-and-validation datasets, the mean (±standard deviation) age was 68.0±12.5 (61.1% male). In internal testing, compared with the experts, the DWI-only and the DWI+AF algorithms respectively achieved moderate (65.3%) and near-strong (79.1%) agreement. In external testing, both algorithms again showed good agreements (59.3%–60.7% and 73.7%–74.0%, respectively). In the clinical trial dataset, compared with the expert consensus, percentage agreements and Cohen’s kappa were respectively 58.1% and 0.34 for the DWI-only vs. 72.9% and 0.57 for the DWI+AF algorithms. The corresponding values between experts were comparable (76.0% and 0.61) to the DWI+AF algorithm.
Conclusion
Our model trained on a large dataset of DWI (both with or without AF information) was able to classify ischemic stroke subtypes comparable to a consensus of stroke experts.

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