http://schca-ir.schmc.ac.kr/handle/2022.oak/158 2026-11-15T13:48:58Z http://schca-ir.schmc.ac.kr/handle/2022.oak/5039 Title: Unsupervised Clustering of 41,728 Emergency Department Visits: Insights into Patient Profiles and KTAS Reliability All Author(s): Jongsun Kim; EunChul Jang; SoonChan Kwon; MyoungJe Song Abstract: Introduction: In the emergency room, it is essential to quickly and accurately classify the patients' various severities. However, existing five-stage classification systems, such as the Korean Emergency Patient Classification Tool (KTAS), do not sufficiently reflect the physiological and clinical heterogeneity of all patients, so there is a possibility of under-classification in some age groups or specific symptom groups. Methods: A retrospective cross-sectional study was conducted using KTAS and the physiological and clinical data of 41,728 patients who visited the emergency room of a university hospital in Incheon in 2022. K-prototypes unsupervised cluster analysis incorporating demographic, physiological, and clinical variables was applied, and the number of clusters was determined as the optimal value through the Silhouette, Dunn, and Davies-Bouldin indicators. Dimension reduction was performed by UMAP, and differences between clusters were compared by t-test, Mann-Whitney U, and chi-square test. Results: Two different clusters were identified. Cluster 0 was a stable patient group with a mean age of 58 years and an average arterial pressure of 104 mmHg. On the other hand, Cluster 1 was a young but physiologically unstable patient group with an average age of 46 years and an average arterial pressure of 90 mmHg. There were significant differences in age, MAP, heart rate, respiratory rate, body temperature, and pain scores between clusters (p < 0.001), and a moderate association was observed between KTAS classification and clusters (Cramer's V = 0.208). Discussion: This study suggested the possibility of early identification of high-risk groups in the emergency room and efficient resource allocation by identifying potential patient heterogeneity that KTAS cannot detect through unsupervised learning. This approach can be used as a basis for precision triage and patient-centered emergency medical policy establishment by supplementing rather than replacing the existing classification system. 2024-12-31T15:00:00Z http://schca-ir.schmc.ac.kr/handle/2022.oak/5004 Title: Association between oil spill clean-up work and thyroid cancer: Nine years of follow-up after the Hebei Spirit oil spill accident All Author(s): Yun-Hee Choi; Lita Kim; Da-An Huh; Kyong Whan Moon; Min-Sung Kang; Yong-Jin Lee Abstract: In 2007, an unprecedented oil spill occurred in Taean, Korea. Although crude oil contains chemicals that could increase thyroid cancer risk, few studies have examined the long-term effects of oil exposure during clean-up and thyroid cancer incidence. We investigated the long-term thyroid cancer incidence among participants involved in clean-up work. 1798 participants engaged in at least two surveys since the baseline was tracked from 2008 to 2018. Participants reported the days they participated in oil clean-up works and cancer diagnoses. Cox proportional hazard models were used to estimate the hazard ratios between clean-up work duration and thyroid cancer. Over the 9-year follow-up, 30 thyroid cancer cases were diagnosed. A positive association was observed between clean-up duration and thyroid cancer risk. This effect was more pronounced among residents living <50 m from traffic roads. Our results indicate that crude oil clean-up work participation may increase the thyroid cancer risk. 2023-12-31T15:00:00Z http://schca-ir.schmc.ac.kr/handle/2022.oak/4972 Title: Association Between Perfluoroalkyl Substance (PFAS) Exposure and Nonalcoholic Fatty Liver Disease in Korean Adults: Results From the KoNEHS 2018-2020: A Cross-Sectional Study All Author(s): Jisuk Yun; Young-Sun Min Abstract: Objectives: Nonalcoholic fatty liver disease (NAFLD) is a major public health problem and the most common chronic liver disease today. In Korea, the prevalence and incidence of NAFLD are currently very high, causing a serious social burden. Perfluoroalkyl substances (PFAS) have been consistently implicated as a potential cause of NAFLD, but research in Koreans is limited. Methods: Using data from the 4th Korean National Environmental Health Survey (KoNEHS, n = 2792), we investigated the association between PFAS blood levels and NAFLD. Multivariable logistic regression models were used to calculate odds ratios (ORs) for the effects of PFAS. A mediation analysis was also conducted to examine the mediating effect of obesity. Finally, weighted quantile sum (WQS) and G-computation methods were implemented to evaluate the joint effect of PFAS mixtures. Hepatic steatosis index was used as a diagnostic tool for NAFLD. [Correction added on 15 May 2025, after first online publication: The KoNEHS n value was changed from 2859 to 2792 in this version.] RESULTS: Through multivariable logistic regression, statistically significant associations with NAFLD were observed for perfluorooctanoic acid (PFOA) (OR 1.09-1.39), perfluorooctansulfonate (PFOS) (1.09-1.40), perfluorohexanesulfonic acid (PFHxS) (1.04-1.22), perfluorononanoic acid (PFNA) (1.12-1.42), and total PFAS (1.21-1.81). We also found that obesity was a significant mediator for PFOA, PFNA, and total PFAS. The ORs for NAFLD obtained by WQS and G-computation methods in the multivariable adjusted model were 1.10-1.46 and 1.08-1.32, respectively. Conclusions: This study confirmed a significant association between some PFAS and increased odds of NAFLD. Excessive exposure to PFAS might explain the high prevalence and incidence of chronic liver disease in Koreans. Long-term cohort studies are needed to assess geographic and occupational exposures in the Korean population. 2024-12-31T15:00:00Z http://schca-ir.schmc.ac.kr/handle/2022.oak/4917 Title: Combination Effect of Caffeine Intake and Thermotherapy on the Blood Levels of Human Irisin and Fibroblast Growth Factor 21 in Healthy Males All Author(s): Hye-Jin Lee; Tae-Hwan Park; Bah-Da Yun; In-Ho Lee; Mid-Eum Moon; Sang-Hyeon Kim; Yi-Rang Lim; Mun-Jeong Kim; Da-Jeong Bae; Jin Kim; Young-Hyun Jung; Jeong-Beom Lee Abstract: Caffeine is a widely consumed psychoactive substance known to influence physiological processes such as heat generation and autonomic nervous system activity. Fibroblast growth factor 21 (FGF-21) and irisin are the biomarkers associated with thermogenesis and metabolic regulation. The study aimed to determine whether thermotherapy along with caffeine intake could increase the blood levels of FGF-21 and irisin. A total of 87 healthy male subjects were randomly divided into a control group and a caffeine intake group. For heat loading, an experiment was performed in which each subject was given a 30-min half-body bath in hot water (42°C ± 0.5°C), and their tympanic temperature (Tty), mean skin temperature (mTs), and serum FGF-21 and irisin levels were measured. Compared to the control group, the caffeine intake group showed significantly increased Tty, mTs, serum FGF-21, and irisin after thermotherapy. Especially, administration of caffeine led to a significantly amplified response in circulating FGF-21 and irisin levels, showing an additional 22.93% and 28.70% increase, respectively, compared to the control group ( P < 0.001). The results suggest that as a new form of synergy, the combination of caffeine intake and thermotherapy could potentially be applied to broader clinical and physiological settings. 2024-12-31T15:00:00Z