1.Associations of Cardiocerebrovascular Risks and Exercise according to Menopausal Status in Women with Type 2 Diabetes Mellitus: A Nationwide Cohort Study
Ji-Hee KO ; Sun Joon MOON ; Kyung-Do HAN ; Hye-Mi KWON ; Se-Eun PARK ; Eun-Jung RHEE ; Won-Young LEE
Diabetes & Metabolism Journal 2026;50(1):101-114
Background:
Menopausal status can increase the risk of cardiocerebrovascular diseases (CCVDs) in women with type 2 diabetes mellitus (T2DM). Regular exercise is well-known to reduce this risk. This study explored the impact of exercise on CCVD and mortality in women with T2DM according to their menopausal status.
Methods:
A total of 32,477 premenopausal and 53,690 postmenopausal Korean women with T2DM aged 40 to 60 years from a national health examination cohort (2009 to 2018) were included. We evaluated risks for stroke, myocardial infarction (MI), and mortality based on exercise intensity. Cox proportional hazard regression analyses were performed to obtain the adjusted hazard ratio (aHR) and 95% confidence interval.
Results:
Exercise reduced stroke, MI, and mortality risks in women with T2DM, regardless of menopausal status. The highest effects of aHR compared to the sedentary group were 0.68 for stroke, 0.66 for MI, and 0.81 for mortality. Postmenopausal women experienced significant MI risk reductions at most exercise intensities, with the greatest reduction in the ≥1,500 metabolic equivalent of task score group unlike premenopausal women. However, stroke and mortality risk reductions in postmenopausal women were less pronounced compared to premenopausal women.
Conclusion
Exercise reduces CCVD risk in women with T2DM across menopausal status. Postmenopausal women with T2DM had more benefits from exercise on MI but fewer benefits on stroke and mortality than premenopausal women. In premenopausal women with T2DM, exercise was not associated with a lower MI risk.
2.Structured Integration of an Artificial Intelligence-Based System for the Optical Diagnosis of Colorectal Polyps
Hae Yeon KANG ; Soonwhan KANG ; Goh Eun CHUNG ; Dong Hoon BAEK ; Hong Sub LEE ; Jinbae PARK ; Sun Young YANG ; Seon Hee LIM ; Ji Min CHOI ; Jung KIM ; Jung Ho BAE
Gut and Liver 2026;20(1):86-96
Background/Aims:
Recent advances in computer-aided diagnosis (CADx) systems have demonstrated expert-level accuracy in the optical diagnosis of colorectal polyps. High-confidence (HC) diagnoses have been defined as those made within 3 seconds without hesitation, and these systems have been shown to improve diagnostic accuracy. We aimed to evaluate the performance of endoscopists with varying levels of experience in diagnosing colorectal polyps with the assistance of a new CADx system applying the 3-second rule and without artificial intelligence assistance.
Methods:
In this multicenter ex vivo study, 35 endoscopists assessed 100 polyps (51 adenomas, 39 hyperplastic polyps, 10 sessile serrated lesions) using narrow-band imaging video clips on an online platform. Assessments consisted of individual endoscopist diagnosis and CADx-assisted diagnosis. HC assignments followed the 3-second rule in both phases. Performance metrics included HC accuracy, HC rate, and adherence to the Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) and Simple Optical Diagnosis Accuracy (SODA) thresholds.
Results:
HC diagnostic accuracy improved from 78.3% (95% confidence interval [CI], 76.6% to 80.0%) to 89.8% (95% CI, 88.6% to 90.9%) with CADx assistance (p<0.001). The proportion of HC predictions increased from 64.2% to 75.4% (p<0.001). Novice endoscopists showed marked improvement with CADx (74.1% vs 88.8%; p<0.001). CADx-assisted diagnoses nearly met SODA and PIVI thresholds under the 3-second rule. Additional analysis demonstrated that CADx assistance significantly improved interobserver agreement and ground truth, particularly for novices (κ=0.37 to κ=0.65; p<0.001).
Conclusions
Integrating CADx with the 3-second rule significantly enhances the performance of endoscopists in the optical diagnosis of colorectal polyps, with the greatest benefit observed among novice endoscopists.
3.Early Onset, High Comorbidity Burden, and Regional Disparities of CADASIL:A Nationwide Cohort Study in South Korea
Ju-Yeun LEE ; Minwoo LEE ; Jae-Sung LIM ; Mi Sun OH ; Kyung-Ho YU ; Young Eun KIM ; Hyeo-Il MA ; Yun Jin KIM ; Jong Ho PARK ; Young Hee JUNG
Journal of Clinical Neurology 2026;22(2):172-182
Background:
and Purpose To compare the epidemiological and clinical features of the rare patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) with age- and sex-matched controls in a nationwide cohort from South Korea.
Methods:
This observational cohort study analyzed newly diagnosed CADASIL patients aged at least 20 years and matched controls using data from the National Health Information Database for 2004–2022. The cumulative incidence of CADASIL was assessed by age and sex, and compared between regions. Neurologic and systemic diseases were compared between the CADASIL and control groups.
Results:
The study analyzed 816 CADASIL patients and 816 age- and sex-matched controls aged 56.8±15.2 years (mean±standard deviation), among whom 48.3% were male. The cumulative incidence of CADASIL was 1.86 per 100,000 people (95% confidence interval [CI]=1.85– 1.87 per 100,000), and peaked at 60–69 years of age. In terms of regional distribution, the incidence was highest for Jeju, at 39.67 per 100,000 (95% CI 37.84–41.49 per 100,000). Neurologic diseases were more frequent in CADASIL patients, including Alzheimer’s disease (33.1% vs.20.0%), vascular dementia (84.9% vs. 5.0%), epilepsy (34.6% vs. 15.9%), stroke (70.7% vs. 27.6%), parkinsonism (18.9% vs. 11.0%), and depression (60.8% vs. 44.9%). Systemic diseases such as diabetes mellitus (78.9% vs. 68.9%) were also more common in CADASIL patients, while cancer (27.9% vs. 38.7%) and myocardial infarction (10.0% vs. 13.6%) were less common than in controls. The onset ages of all diseases were lower in CADASIL patients.
Conclusions
This study has provided a precise nationwide estimate of the CADASIL incidence and its regional distribution in South Korea. CADASIL patients showed higher incidence rates and earlier onsets of diverse clinical manifestations.
4.Early-Onset Dementia Risk Escalates with Diabetes Duration: Insights from a Nationwide Cohort Study
Ji-Hong PARK ; Sun-Joon MOON ; Da Yeon LEE ; Ji-Hee KO ; Han Na JANG ; Hye-Mi KWON ; Se-Eun PARK ; Kyung-Do HAN ; Eun-Jung RHEE ; Won-Young LEE
Endocrinology and Metabolism 2026;41(2):235-244
Background:
The prevalence of diabetes mellitus and early-onset dementia (EOD), defined as dementia diagnosed at an age <65 years, is increasing worldwide, with significant socioeconomic implications. We investigated the association between diabetes, prediabetes, and EOD, focusing on the influence of diabetes duration on EOD risk.
Methods:
Using the Korean National Health Insurance Service database, we analyzed data from 1,979,509 patients aged 40–60 years who underwent health checkups in 2009. Patients were categorized into five groups: normal, impaired fasting glucose (IFG), newly diagnosed diabetes, diabetes duration <5 years, and diabetes duration ≥5 years. Cox proportional hazard models were used to estimate the adjusted hazard ratios (aHRs) for EOD after adjusting for demographic and clinical covariates.
Results:
During the observation period (mean 7.75 years), 8,921 patients with EOD were identified. The diabetes group demonstrated a significantly higher incidence of EOD compared to the normal group (aHR, 1.334; 95% confidence interval [CI], 1.226 to 1.451). EOD risk increased with longer diabetes duration, with the highest risk observed in patients with diabetes ≥5 years (aHR, 1.543; 95% CI, 1.368 to 1.741). No significant difference was observed between the IFG and normal groups (aHR, 0.989; 95% CI, 0.938 to 1.043). Additionally, the hypertension group exhibited a significantly higher incidence of EOD compared to the non-hypertension group (aHR, 1.364; 95% CI, 1.291 to 1.442).
Conclusion
Diabetes is independently associated with increased risk of EOD, and this risk increases with longer diabetes duration. This association remained significant regardless of the presence and duration of hypertension.
5.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part II. Follow-up Surveillance after Initial Treatment 2026
Eun Kyung LEE ; Seung Heon KANG ; Bon Seok KOO ; Mijin KIM ; Min Joo KIM ; Bo Hyun KIM ; Ji Won KIM ; Dong Gyu NA ; Sohyun PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Young-Ik SON ; Young Shin SONG ; Dong Yeob SHIN ; Jong-Hyuk AHN ; Hwa Young AHN ; So Won OH ; Ho-Ryun WON ; Won Sang YOO ; Min Kyoung LEE ; Sang-Woo LEE ; Jeongmin LEE ; Ji Ye LEE ; Dong-Jun LIM ; Ki-Wook CHUNG ; Ari CHONG ; Jin Hyang JUNG ; Sun Wook CHO ; Yoon Young CHO ; Chae Moon HONG ; Young Joo PARK ;
International Journal of Thyroidology 2026;19(1):1-40
In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.
6.The Prevalence of BRAF Mutation in Papillary Thyroid Carcinoma Decreases Significantly with Increasing Tumor Size
Da Eun LEEM ; Hyunju PARK ; Ji Hyun YOO ; Bo Ram KIM ; Young Lyun OH ; Tae Hyuk KIM ; Sun Wook KIM ; Jae Hoon CHUNG
International Journal of Thyroidology 2026;19(1):95-103
Background and Objectives:
Studies investigating the correlation between papillary thyroid carcinoma (PTC) tumor size and the prevalence of the B-type Raf kinase (BRAF) mutation have yielded conflicting results. Therefore, we evaluated the prevalence of BRAF mutation according to tumor size in a large cohort of PTC patients to clarify this association.
Materials and Methods:
We retrospectively analyzed 6,438 patients with surgically diagnosed classic PTC between January 2009 and December 2017 at Samsung Medical Center, Seoul, Republic of Korea.During the study period, BRAF mutation testing was attempted on all fine-needle aspiration specimens, except for a small number of inadequate specimens. All other histologic subtypes were excluded. The prevalence of BRAF mutation was assessed based on tumor size, and further analyzed by age group and sex according to tumor size.
Results:
The overall prevalence of BRAF mutation was 79.2%. When PTCs ≤1 cm were excluded, the prevalence was 77.2%. The prevalence significantly decreased with increasing tumor size (p for trend <0.001). It was significantly higher in men than in women (p=0.013), but did not differ by age. The inverse correlation between tumor size and prevalence was prominent in patients aged 20-49 years but was less distinct in those aged 50 years and older.
Conclusion
In this large cohort of patients with PTC, the prevalence of BRAF mutation significantly decreased with increasing tumor size. These findings suggest that BRAF mutation is enriched in smaller surgically treated classic PTCs and may provide a hypothesis-generating clue regarding its role in early PTC development, although selection bias cannot be excluded.
7.Ethnic Heterogeneity in Reproductive Risk Factors for Breast Cancer, With a Focus on Asian Populations:A Meta-analysis
Youjin HONG ; Soseul SUNG ; Woojin LIM ; Sungji MOON ; Kwang-Pil KO ; Jung Eun LEE ; Inah KIM ; Sun Ha JEE ; Sun-Seog KWEON ; Min-Ho SHIN ; Sangmin PARK ; Seung-Ho RYU ; Sun Young YANG ; Jeongseon KIM ; Sang-Wook YI ; Sue K. PARK
Journal of Cancer Prevention 2026;31(1):20-27
suggest that some reproductive factors associated with BC differ across ethnicities and time trends, perhaps due to the prevalence of reproductive factors and the baseline hazard of BC.
8.Nationwide Survey on Endoscopic Submucosal Dissection for Early Gastric Cancer in Korea: Results From the Korean College of Helicobacter and Upper Gastrointestinal Research (KCHUGR) 2023 Survey
Jae Yong PARK ; Jeong Hoon LEE ; Tae-Se KIM ; Da Hyun JUNG ; Bong Eun LEE ; Yonghoon CHOI ; Wan-Sik LEE ; Young-Il KIM ; Sun Hyung KANG ; Hyunsoo CHUNG ; Su Jin KIM ; Joon Sung KIM ; Donghoon KANG ; Su Youn NAM ; Seung Han KIM ; Hyo-Joon YANG ; Hyun LIM ; Jin LEE ; Seon-Young PARK ; Seung-Woo LEE ; Sun Moon KIM ; Sam Ryong JEE ; Dae Young CHEUNG ; Chung Hyun TAE ; Seokin KANG ; Sung Chul PARK ; Seung In SEO ; Cheol Min SHIN ; Kee Don CHOI ; Jong Yeul LEE ;
The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2026;26(1):50-59
Objectives:
Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research.
Methods:
Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes.
Results:
Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days.
Conclusions
This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.
9.Applying National Whole-genome Sequencing Findings for Rare Diseases in Clinical Practice: The Imperative of a Multidisciplinary Approach
Kyung Sun PARK ; Sunghwan SHIN ; Jong-Ho PARK ; Young-Eun KIM ; Won Kyung KWON ; Min-Kyung SO ; Changhee HA ; Ja-Hyun JANG ; Taeheon LEE ; Chang-Seok KI ; Yoonjung KIM ; Kyung-A LEE ; Inho PARK ; Sejoon LEE ; Hong-Hee WON ; ; Jong-Won KIM
Annals of Laboratory Medicine 2026;46(1):94-103
Background:
As nationwide government-led whole-genome sequencing (WGS) projects progress, optimizing the clinical integration of large-scale WGS results is crucial. We explored how the initial analysis from Korea’s First WGS Pilot Study for Rare Diseases was applied in clinical practice, and then we reanalyzed the data comprehensively at Samsung Medical Center (SMC) Seoul, Korea.
Methods:
A prospective cohort study designed to collect WGS data under a Korean national initiative was conducted from August 2020 to December 2021. We focused on patients with rare diseases recruited from 16 university hospitals. The participants included 5,000 individuals (2,200 probands and 2,800 family members). The initial WGS data and diagnostic reference reports (from 682 probands and 484 family members), generated based on the First Korean WGS Pilot Study for Rare Diseases, were subsequently reanalyzed by SMC.
Results:
The initial analysis of the First Korean WGS Pilot Study data revealed a diagnostic rate of 17%. Upon receiving these results, the SMC conducted two rounds of reanalysis, increasing the diagnostic rate from 15% in the first analysis, to 18% in the second, and finally to 24% in the third (P = 1.6 × 10 −5 ). Key factors in improving the genetic diagnosis included increased detection of novel (likely) pathogenic variants (P = 1.0 × 10 −4 ), improved diagnostic rates with larger family recruitment (P = 0.004), and refined clinical information for more precise genotype–phenotype correlation analysis (40%).
Conclusions
Although national WGS projects lay a foundation for rare disease diagnosis, hospital-level reanalysis and multidisciplinary collaborations are crucial for optimizing diagnostic outcomes.
10.Nationwide Survey on Endoscopic Submucosal Dissection for Early Gastric Cancer in Korea: Results From the Korean College of Helicobacter and Upper Gastrointestinal Research (KCHUGR) 2023 Survey
Jae Yong PARK ; Jeong Hoon LEE ; Tae-Se KIM ; Da Hyun JUNG ; Bong Eun LEE ; Yonghoon CHOI ; Wan-Sik LEE ; Young-Il KIM ; Sun Hyung KANG ; Hyunsoo CHUNG ; Su Jin KIM ; Joon Sung KIM ; Donghoon KANG ; Su Youn NAM ; Seung Han KIM ; Hyo-Joon YANG ; Hyun LIM ; Jin LEE ; Seon-Young PARK ; Seung-Woo LEE ; Sun Moon KIM ; Sam Ryong JEE ; Dae Young CHEUNG ; Chung Hyun TAE ; Seokin KANG ; Sung Chul PARK ; Seung In SEO ; Cheol Min SHIN ; Kee Don CHOI ; Jong Yeul LEE ;
Journal of Gastric Cancer 2026;26(2):169-183
Purpose:
Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research.
Materials and Methods:
Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes.
Results:
Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days.
Conclusions
This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

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