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.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.
3.Patients participation in multidisciplinary management in gastric cancer: regulation comparison and expert survey among major countries
Kyoyoung PARK ; Hyuk-Joon LEE ; Seong-Ho KONG ; Do Joong PARK ; Hyunsoo CHUNG ; Soo-Jeong CHO ; Seock-Ah IM ; Yoonjin KWAK ; Hye Seung LEE ; Eui Kyu CHIE ; Jimmy Bok Yan SO ; Zekuan XU ; Narikazu BOKU ; Jiafu JI ; Yuko KITAGAWA ; Raul J ROSENTHAL ; Takeshi SANO ; Han-Kwang YANG
Korean Journal of Clinical Oncology 2025;21(3):143-149
Purpose:
In Korea, the Health Insurance Review and Assessment Service (HIRA) mandates patient participation in outpatient multidisciplinary team (MDT) meetings as part of national cancer quality assessment. However, the necessity of involving patients and families in MDT discussions remains debatable. This study explored international expert perspectives on patient participation in gastric cancer MDTs.
Methods:
A cross-national expert survey was conducted in September 2021 among 15 gastric cancer specialists from Korea, China, Japan, Singapore, and the United States. The survey assessed the frequency of patient and family member attendance, perceived pros and cons, and preferences regarding mandatory versus selective involvement. Additionally, MDT structures and policies were reviewed by countries.
Results:
Most respondents reported that patients and families rarely or never attend MDT meetings: nine stated that patients are never included, three reported “usually not,” and three indicated “sometimes.” None consistently included patients. The most cited benefits were sharing opinions with patients and families simultaneously, followed by improved explanation of treatment and legal protection. Major concerns included hindered discussion, inefficiency, and logistical challenges. Only four respondents supported routine participation, while 11 favored case-dependent involvement.
Conclusion
International experts do not widely support mandatory patient participation in MDT meetings. A flexible approach that allows MDTs to operate with or without patient involvement may better reflect actual clinical practice.
4.Surgical extraction of a sublingually-displaced retained root with the aid of a magnetic field-based dynamic navigation system: a case study
Yoo-Sung NAM ; Seung-Eun LEE ; Sung-Ah CHE ; Sang-Yoon PARK ; Soo-Hwan BYUN ; Byoung-Eun YANG ; Sangmin YI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2024;50(6):367-372
The submandibular displacement of a mandibular third molar residual root presents major challenges to oral and maxillofacial surgeons due to the proximity to critical anatomical structures such as the lingual nerve and sublingual artery. Preoperative imaging can approximate the location of the residual tooth root; however, accurately determining its exact position is difficult because of the dynamic nature of the mandible and the difficulty of realtime synchronization of imaging. This study presents the successful extraction of a residual mandibular third molar root in a 67-year-old female patient achieved using a magnetic field-based navigation system. The sublingually-displaced residual root was localized using the navigation system, marked using a virtual implant placement, and positioned by a hand piece using synchronized real-time sensor data. The root was successfully removed with a minimally-invasive approach. No complications occurred postoperatively, and follow-up showed no major issues. Due to the small size of the marker, ease of calibration, and independence from visual obstacles, magnetic field-based navigation systems are a promising tool for the removal of residual roots displaced into adjacent soft tissue.
5.Cohort profile: Multicenter Networks for Ideal Outcomes of Rare Pediatric Endocrine and Metabolic Diseases in Korea (OUTSPREAD study)
Yun Jeong LEE ; Chong Kun CHEON ; Junghwan SUH ; Jung-Eun MOON ; Moon Bae AHN ; Seong Hwan CHANG ; Jieun LEE ; Jin Ho CHOI ; Minsun KIM ; Han Hyuk LIM ; Jaehyun KIM ; Shin-Hye KIM ; Hae Sang LEE ; Yena LEE ; Eungu KANG ; Se Young KIM ; Yong Hee HONG ; Seung YANG ; Heon-Seok HAN ; Sochung CHUNG ; Won Kyoung CHO ; Eun Young KIM ; Jin Kyung KIM ; Kye Shik SHIM ; Eun-Gyong YOO ; Hae Soon KIM ; Aram YANG ; Sejin KIM ; Hyo-Kyoung NAM ; Sung Yoon CHO ; Young Ah LEE
Annals of Pediatric Endocrinology & Metabolism 2024;29(6):349-355
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.
6.Cohort profile: Multicenter Networks for Ideal Outcomes of Rare Pediatric Endocrine and Metabolic Diseases in Korea (OUTSPREAD study)
Yun Jeong LEE ; Chong Kun CHEON ; Junghwan SUH ; Jung-Eun MOON ; Moon Bae AHN ; Seong Hwan CHANG ; Jieun LEE ; Jin Ho CHOI ; Minsun KIM ; Han Hyuk LIM ; Jaehyun KIM ; Shin-Hye KIM ; Hae Sang LEE ; Yena LEE ; Eungu KANG ; Se Young KIM ; Yong Hee HONG ; Seung YANG ; Heon-Seok HAN ; Sochung CHUNG ; Won Kyoung CHO ; Eun Young KIM ; Jin Kyung KIM ; Kye Shik SHIM ; Eun-Gyong YOO ; Hae Soon KIM ; Aram YANG ; Sejin KIM ; Hyo-Kyoung NAM ; Sung Yoon CHO ; Young Ah LEE
Annals of Pediatric Endocrinology & Metabolism 2024;29(6):349-355
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.
7.Cohort profile: Multicenter Networks for Ideal Outcomes of Rare Pediatric Endocrine and Metabolic Diseases in Korea (OUTSPREAD study)
Yun Jeong LEE ; Chong Kun CHEON ; Junghwan SUH ; Jung-Eun MOON ; Moon Bae AHN ; Seong Hwan CHANG ; Jieun LEE ; Jin Ho CHOI ; Minsun KIM ; Han Hyuk LIM ; Jaehyun KIM ; Shin-Hye KIM ; Hae Sang LEE ; Yena LEE ; Eungu KANG ; Se Young KIM ; Yong Hee HONG ; Seung YANG ; Heon-Seok HAN ; Sochung CHUNG ; Won Kyoung CHO ; Eun Young KIM ; Jin Kyung KIM ; Kye Shik SHIM ; Eun-Gyong YOO ; Hae Soon KIM ; Aram YANG ; Sejin KIM ; Hyo-Kyoung NAM ; Sung Yoon CHO ; Young Ah LEE
Annals of Pediatric Endocrinology & Metabolism 2024;29(6):349-355
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.
8.Surgical extraction of a sublingually-displaced retained root with the aid of a magnetic field-based dynamic navigation system: a case study
Yoo-Sung NAM ; Seung-Eun LEE ; Sung-Ah CHE ; Sang-Yoon PARK ; Soo-Hwan BYUN ; Byoung-Eun YANG ; Sangmin YI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2024;50(6):367-372
The submandibular displacement of a mandibular third molar residual root presents major challenges to oral and maxillofacial surgeons due to the proximity to critical anatomical structures such as the lingual nerve and sublingual artery. Preoperative imaging can approximate the location of the residual tooth root; however, accurately determining its exact position is difficult because of the dynamic nature of the mandible and the difficulty of realtime synchronization of imaging. This study presents the successful extraction of a residual mandibular third molar root in a 67-year-old female patient achieved using a magnetic field-based navigation system. The sublingually-displaced residual root was localized using the navigation system, marked using a virtual implant placement, and positioned by a hand piece using synchronized real-time sensor data. The root was successfully removed with a minimally-invasive approach. No complications occurred postoperatively, and follow-up showed no major issues. Due to the small size of the marker, ease of calibration, and independence from visual obstacles, magnetic field-based navigation systems are a promising tool for the removal of residual roots displaced into adjacent soft tissue.
9.Identification of acute myocardial infarction and stroke events using the National Health Insurance Service database in Korea
Minsung CHO ; Hyeok-Hee LEE ; Jang-Hyun BAEK ; Kyu Sun YUM ; Min KIM ; Jang-Whan BAE ; Seung-Jun LEE ; Byeong-Keuk KIM ; Young Ah KIM ; JiHyun YANG ; Dong Wook KIM ; Young Dae KIM ; Haeyong PAK ; Kyung Won KIM ; Sohee PARK ; Seng Chan YOU ; Hokyou LEE ; Hyeon Chang KIM
Epidemiology and Health 2024;46(1):e2024001-
OBJECTIVES:
The escalating burden of cardiovascular disease (CVD) is a critical public health issue worldwide. CVD, especially acute myocardial infarction (AMI) and stroke, is the leading contributor to morbidity and mortality in Korea. We aimed to develop algorithms for identifying AMI and stroke events from the National Health Insurance Service (NHIS) database and validate these algorithms through medical record review.
METHODS:
We first established a concept and definition of “hospitalization episode,” taking into account the unique features of health claims-based NHIS database. We then developed first and recurrent event identification algorithms, separately for AMI and stroke, to determine whether each hospitalization episode represents a true incident case of AMI or stroke. Finally, we assessed our algorithms’ accuracy by calculating their positive predictive values (PPVs) based on medical records of algorithm- identified events.
RESULTS:
We developed identification algorithms for both AMI and stroke. To validate them, we conducted retrospective review of medical records for 3,140 algorithm-identified events (1,399 AMI and 1,741 stroke events) across 24 hospitals throughout Korea. The overall PPVs for the first and recurrent AMI events were around 92% and 78%, respectively, while those for the first and recurrent stroke events were around 88% and 81%, respectively.
CONCLUSIONS
We successfully developed algorithms for identifying AMI and stroke events. The algorithms demonstrated high accuracy, with PPVs of approximately 90% for first events and 80% for recurrent events. These findings indicate that our algorithms hold promise as an instrumental tool for the consistent and reliable production of national CVD statistics in Korea.
10.Diagnostic Utility of Whole Genome Sequencing After Negative Karyotyping/Chromosomal Microarray in Infants Born With Multiple Congenital Anomalies
Misun YANG ; Jee Ah KIM ; Heui Seung JO ; Jong-Ho PARK ; So Yoon AHN ; Se In SUNG ; Won Soon PARK ; Hye-Won CHO ; Jeong-Min KIM ; Mi-Hyun PARK ; Hyun-Young PARK ; Ja-Hyun JANG ; Yun Sil CHANG
Journal of Korean Medical Science 2024;39(36):e250-
Background:
Achieving a definitive genetic diagnosis of unexplained multiple congenital anomalies (MCAs) in neonatal intensive care units (NICUs) infants is challenging because of the limited diagnostic capabilities of conventional genetic tests. Although the implementation of whole genome sequencing (WGS) has commenced for diagnosing MCAs, due to constraints in resources and faculty, many NICUs continue to utilize chromosomal microarray (CMA) and/or karyotyping as the initial diagnostic approach. We aimed to evaluate the diagnostic efficacy of WGS in infants with MCAs who have received negative results from karyotyping and/or CMA.
Methods:
In this prospective study, we enrolled 80 infants with MCAs who were admitted to a NICU at a single center and had received negative results from CMA and/or karyotyping.The phenotypic characteristics were classified according to the International Classification of Diseases and the Human Phenotype Ontology. We assessed the diagnostic yield of trioWGS in infants with normal chromosomal result and explored the process of diagnosing by analyzing both phenotype and genotype. Also, we compared the phenotype and clinical outcomes between the groups diagnosed with WGS and the undiagnosed group. Results: The diagnostic yield of WGS was 26% (21/80), of which 76% were novel variants.There was a higher diagnostic yield in cases of craniofacial abnormalities, including those of the eye and ear, and a lower diagnostic yield in cases of gastrointestinal and genitourinary abnormalities. In addition, higher rates of rehabilitation therapy and gastrostomy were observed in WGS-diagnosed infants than in undiagnosed infants.
Conclusion
This prospective cohort study assessed the usefulness of trio-WGS following chromosomal analysis for diagnosing MCAs in the NICU and revealed improvements in the diagnostic yield and clinical utility of WGS.

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