1.Postpartum bone mineral density in Korean women: associations with lactation status and calcium intake
Cheawon LEE ; Hangyeol JEON ; Yoon Ha KIM ; Myeong Gyun CHOI ; Jong Woon KIM ; Clara Yongjoo PARK
Nutrition Research and Practice 2026;20(1):145-155
BACKGROUND/OBJECTIVES:
Postpartum bone metabolism undergoes substantial alterations based on breastfeeding status. Research on maternal calcium intake and bone recovery, particularly among Asian women, remains limited. This study investigated postpartum change in bone mineral density (BMD) and its association with calcium intake during late pregnancy and post-delivery according to breastfeeding status.
SUBJECTS/METHODS:
Thirty-six women (22 breastfeeding, 14 non-breastfeeding) underwent dual-energy X-ray absorptiometry 3 times: 1) within 3 days of delivery, 2) at 6 mon postpartum for non-breastfeeding women or within 1 mon of weaning for breastfeeding women, and 3) at 12 mon postpartum. Dietary calcium intake was evaluated using a food frequency questionnaire and dietary supplement survey at all visits. Association between calcium intake with percentage change in BMD (%ΔBMD) was assessed by linear regression.
RESULTS:
The BMD at the lumbar spine, total hip, femoral neck, and trochanter significantly decreased during breastfeeding, whereas non-breastfeeding women displayed increased BMD at the femoral neck at 6 mon postpartum. In non-breastfeeding women, postpartum calcium intake was positively associated with %ΔBMD at the total hip, femoral neck, and intertrochanter (P < 0.05). Few significant associations were observed between %ΔBMD and late pregnancy intakes across all women, regardless of breastfeeding status. At 12 mon, BMD in breastfeeding women recovered to delivery levels, while non-breastfeeding women maintained their BMD observed at 6 mon postpartum.
CONCLUSION
Postpartum calcium intake is positively associated with bone recovery in non-breastfeeding women, suggesting that its effects on bone recovery potentially vary with lactation status.
2.Clinical Application of Pharmacogenomics in Stroke Management: Current Evidence and Future Directions
Keon-Joo LEE ; Minkyung KANG ; Eung Joon LEE ; Jaeseong OH ; Na-Young HAN ; Jeong-Yoon LEE ; Joo-Yeon LEE ; Soo Ji LEE ; Stéphanie DEBETTE ; Guillaume PARÉ ; Daniel WOO ; Andrew ELDEIRY ; Young Seo KIM ; Jinkwon KIM ; Jong-Moo PARK ; Juneyoung LEE ; Joohon SUNG ; Jay Chol CHOI ; Hee-Joon BAE
Journal of Stroke 2026;28(1):58-75
Pharmacogenomic variations may significantly influence responses to commonly prescribed stroke medications. Despite accumulating evidence, genetic testing has not yet been widely integrated into stroke care. This review summarizes current evidence and provides practical guidance for clinical implementation. Pharmacogenomic studies and clinical guidelines related to antiplatelet agents, anticoagulants, and statins were reviewed, with particular emphasis on East Asian populations. Substantial evidence supports genotype-guided use of clopidogrel (CYP2C19), warfarin (CYP2C9, VKORC1, CYP4F2), and statins (SLCO1B1, ABCG2). For aspirin, PTGS1/2 and PEAR1 variants have been investigated; however, current data remain insufficient for clinical application. Regarding direct oral anticoagulants (DOACs), candidate genes such as ABCB1 and CES1 demonstrate pharmacokinetic associations, though robust clinical outcome data are lacking. Distinct allele frequencies in East Asians—such as higher prevalence of CYP2C19 and ABCG2 variants—underscore the need for population-specific strategies. Beyond single-gene approaches, polygenic risk scores, pharmacogenomic panels, and integration with multi-omics data and artificial intelligence represent promising directions for personalized therapy. Pharmacogenomic testing can enhance stroke pharmacotherapy, particularly in populations with high frequencies of actionable variants. Broader implementation requires rapid testing platforms, clinician education, tailored clinical guidelines, and real-world validation of aspirin, DOACs, and multi-gene approaches. Future research should expand population-specific studies and integrate pharmacogenomics within the broader framework of precision medicine to ensure equitable clinical benefit.
3.AI-driven Medical Care: Evaluation of Large Language Models in Generating Personalized Stroke Education Materials
Surim YOON ; Woo-Keun SEO ; Kyungseo KIM ; Seongvin JU ; Hyun Kyung KIM ; Hyung Jun KIM ; Jong-Won CHUNG ; Oh Young BANG ; Gyeong-Moon KIM ; Eun Young LEE ; Youngrak CHOI ; Soyoung YOO
Healthcare Informatics Research 2026;32(2):179-189
Objectives:
Large language models (LLMs) demonstrate remarkable potential in healthcare communication. However, whether they can process complex, high-volume medical information, such as stroke-related content, remains insufficiently validated. This study aimed to evaluate the natural language processing capabilities of LLMs in handling such content and to develop an evaluation instrument.
Methods:
A survey compared educational materials generated by two LLMs (ChatGPT 4.0 and Claude 3) with neurologist-authored content on stroke. The materials were based on two clinical scenarios representing distinct stroke etiologies: cardioembolism and large-artery atherosclerosis. They were evaluated in terms of accuracy, legality, ethics, comprehensiveness, and information delivery. Scores for comprehensiveness and information delivery were compared according to participants’ agreement with the use of LLMs in healthcare.
Results:
ChatGPT received the highest scores across all domains, except for legality in Scenario 2. In Scenario 1, the ranking for accuracy and summarization of clinical information was, from highest to lowest, ChatGPT, Claude, and the neurologist (η2 = 0.140, p < 0.001; η2 = 0.175, p < 0.001). The same hierarchy was observed in Scenario 2 for accuracy (η2 = 0.077, p < 0.001) and summarization (η2 = 0.194, p < 0.001). Participants who agreed with the use of LLMs in healthcare assigned higher scores for the comprehensiveness (Scenario 1, p = 0.005; Scenario 2, p = 0.007) and information delivery (Scenario 1, p = 0.003; Scenario 2, p = 0.026) of ChatGPT-generated materials than participants who did not agree.
Conclusions
LLMs demonstrated adequate capability to convey complex content, such as stroke-related information, in an accessible and understandable manner for non-experts.
4.Consensus of Korean Asthma Study Group on Definition of Clinical Remission in Severe Asthma: A Modified Delphi Study
Sun Hye SHIN ; Joon Young CHOI ; Junghee YOON ; Youlim KIM ; Jong Geol JANG ; Ji-Yong MOON ; Chin Kook RHEE ; Kyung Hoon MIN ; Yong Il HWANG ; Yeon-Mok OH ; Seong Yong LIM ;
Tuberculosis and Respiratory Diseases 2026;89(2):215-225
Background:
Asthma remission has recently emerged as an aspirational treatment goal, yet its definition remains inconsistent across studies and expert groups. The absence of a standardized framework hampers its application in clinical practice and research, particularly in Korea where biologics use is rapidly increasing. This study aimed to establish a consensus definition of clinical remission in severe asthma among Korean experts.
Methods:
A two-round modified Delphi survey, followed by a focused third round, was conducted among 28 board-certified pulmonologists from the Korean Academy of Tuberculosis and Respiratory Diseases (KATRD). The questionnaire consisted of six domains and 27 items. Responses were analyzed using agreement rates, interquartile ranges, and content validity ratios to determine consensus levels.
Results:
Consensus was reached on defining clinical remission as a composite of no exacerbations, no systemic corticosteroid use, sustained symptom control (Asthma Control Test ≥20 on at least three occasions over 12 months), and stabilization and optimization of pulmonary function while on maintenance treatment. Experts agreed that pulmonary function should be assessed based on clinical judgment rather than absolute thresholds. Complete remission was additionally defined as fulfilling all clinical remission criteria with normalization of type 2 inflammation (blood eosinophils <300/μL and fractional exhaled nitric oxide <25 ppb).
Conclusion
This Delphi consensus provides a regionally relevant and pragmatic framework for defining remission in severe asthma. These statements may help guide clinical practice, inform guideline development, and support future research on remission as a treatment goal.
5.Korean Medication Algorithm Project for Depressive Disorder 2025:Comparisons with Other Treatment Guidelines
Won-Seok CHOI ; Young Sup WOO ; Won-Myong BAHK ; Nak-Young KIM ; Jeong Seok SEO ; Sheng-Min WANG ; Won KIM ; Sung-Yong PARK ; Jung Goo LEE ; Chan-Mo YANG ; Hyung Mo SUNG ; Young-Eun JUNG ; Moon-Doo KIM ; Jong-Hyun JEONG ; Bo-Hyun YOON ; Kyung Joon MIN
Clinical Psychopharmacology and Neuroscience 2026;24(1):2-14
The sixth edition of the Korean Medication Algorithm Project for Depressive Disorder (KMAP-DD) was published in 2025. This review compared KMAP-DD 2025 with four major international clinical practice guidelines: Canadian Network for Mood and Anxiety Treatments Clinical Guidelines for the Management of Major Depressive Disorders, National Institute for Health and Care Excellence Depression Guideline, Royal Australian and New Zealand College of Psychiatrists Clinical Practice Guidelines for Mood Disorders, and British Association for Psychopharmacology Guideline. While KMAP-DD is based on expert consensus, and others on evidence-based methods, overall treatment strategies for depressive episodes were fairly consistent. Especially, KMAP-DD 2025 offers more structured recommendations in areas lacking strong evidence, such as premenstrual dysphoric disorder, perinatal depression, and depression with medical comorbidities. KMAP-DD 2025 also reflected Korean clinical practice patterns emphasizing rapid symptom relief and early use of combination strategies. Despite limitations as a consensus-based guideline, KMAP-DD 2025 complements evidence-based approaches and provides practical, situation-specific guidance for real-world clinical decision-making in Korea.
6.Establishing an Active Vaccine Safety Surveillance System Using Large Scale Databases in Korea: Lessons and Scalable Insights for Global Application
Jin Gu YOON ; Eliel NHAM ; Yu Jung CHOI ; Min Joo CHOI ; Won Suk CHOI ; Young Kyung YOON ; Yu Bin SEO ; Hakjun HYUN ; Jung Yeon HEO ; Jin-Soo LEE ; Chung-Jong KIM ; Ji Yun NOH ; Joon Young SONG ; Hee Jin CHEONG
Journal of Korean Medical Science 2026;41(1):e47-
Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.
7.Male preference for TERT alterations and HBV integration in young-age HBV-related HCC: implications for sex disparity
Jin Seoub KIM ; Hye Seon KIM ; Kwon Yong TAK ; Ji Won HAN ; Heechul NAM ; Pil Soo SUNG ; Sung Won LEE ; Jung Hyun KWON ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Jeong Won JANG
Clinical and Molecular Hepatology 2025;31(2):509-524
Background/Aims:
Hepatocellular carcinoma (HCC) exhibits significant sex disparities in incidence, yet its molecular mechanisms remain unclear. We explored the role of telomerase reverse transcriptase (TERT) genetic alterations and hepatitis B virus (HBV) integration, both known major contributors to HCC, in sex-specific risk for HBV-related HCC.
Methods:
We examined 310 HBV-related HCC tissues to investigate sex-specific TERT promoter (TERT-pro) mutations and HBV integration profiles, stratified by sex and age, and validated with single-cell RNA sequencing (scRNA-seq) data.
Results:
Tumors predominantly exhibited TERT-pro mutations (26.0% vs. 0%) and HBV-TERT integration (37.0% vs. 3.0%) compared to non-tumorous tissues. While TERT-pro mutations increased with age in both sexes, younger males (≤60 years) showed marked predominance compared to younger females. Males had significantly more HBV integrations at younger ages, while females initially had fewer integrations that gradually increased with age. Younger males' integrations showed significantly greater enrichment in the TERT locus compared to younger females, alongside a preference for promoters, PreS/S regions, and CpG islands. Overall, TERT genetic alterations were significantly sex-differential in younger individuals (75.3% in males vs. 23.1% in females) but not in older individuals (76.9% vs. 83.3%, respectively). These alterations were associated with increased TERT expression. The skewed TERT abnormalities in younger males were further corroborated by independent scRNA-seq data.
Conclusions
Our findings highlight the critical role of TERT alterations and HBV integration patterns in the male predominance of HCC incidence among younger HBV carriers, offering insights for future exploration to optimize sex-specific patient care and HCC surveillance strategies.
8.Optimal tacrolimus levels for reducing CKD risk and the impact of intrapatient variability on CKD and ESRD development following liver transplantation
Soon Kyu LEE ; Ho Joong CHOI ; Young Kyoung YOU ; Pil Soo SUNG ; Seung Kew YOON ; Jeong Won JANG ; Jong Young CHOI
Clinical and Molecular Hepatology 2025;31(1):131-146
Background/Aims:
This study aimed to identify the risk factors for chronic kidney disease (CKD) and end-stage renal disease (ESRD) following liver transplantation (LT), with a specific focus on tacrolimus levels and intrapatient variability (IPV).
Methods:
Among the 1,076 patients who underwent LT between 2000 and 2018, 952 were included in the analysis. The tacrolimus doses and levels were recorded every 3 months, and the IPV was calculated using the coefficient of variability. The cumulative incidence rates of CKD and ESRD were calculated based on baseline kidney function at the time of LT. The impact of tacrolimus levels and their IPV on the development of CKD and ESRD was evaluated, and the significant risk factors were identified.
Results:
Within a median follow-up of 97.3 months, the 5-year cumulative incidence rates of CKD (0.58 vs. 0.24) and ESRD (0.07 vs. 0.01) were significantly higher in the acute kidney injury group than in the normal glomerular filtration rate (GFR) group. In the normal GFR group, the tacrolimus levels were identified as a risk factor for CKD, with a level of ≤4.5 ng/mL suggested as optimal for minimizing the risk of CKD. Furthermore, the IPV of tacrolimus levels and doses emerged as a significant risk factor for CKD development in both groups (p<0.05), with tenofovir disoproxil fumarate also being a risk factor in HBV-infected patients. The IPV of tacrolimus levels was also a significant factor in ESRD development (p<0.05).
Conclusions
This study elucidated the optimal tacrolimus trough level and highlighted the impact of IPV on the CKD and ESRD development post-LT.
9.Long-term Effects and Prognostic Factors of Accelerated Cross-Linking with Retention Ring-assisted Riboflavin Application on Keratoconus Progression
Seonghwan KIM ; Won Jong CHOI ; Chang Ho YOON ; Mee Kum KIM
Korean Journal of Ophthalmology 2025;39(2):145-156
Purpose:
To evaluate the long-term efficacy, safety, and prognostic factors of pulsed-light accelerated corneal collagen cross-linking (A-CXL) with continuous riboflavin application to halt keratoconus progression
Methods:
A-CXL with retention ring-assisted continuous riboflavin application for either 10 or 5 minutes was performed in 37 eyes of 33 patients with progressive keratoconus between 2016 and 2020. Successful halting rates and prognostic factors of time-dependent changes in keratometric values, visual acuity, refractive errors, topographic indices, central corneal thickness, thinnest corneal thickness, irregularity at 3- and 5-mm zone, and endothelial cell density were evaluated.
Results:
Survival analysis showed successful halting rates of 71% and 89% in A-CXL with 5- and 10-minute–applied riboflavin, respectively. Best-corrected visual acuity significantly improved after A-CXL in both groups. Maximum keratometry decreased significantly from 52.52 to 50.39 diopters (p < 0.001) in the 10-minute group, while there was no significant decrease in the 5-minute group (52.77–51.80 diopters, p = 0.146). irregularity in 3- and 5-mm zone decreased significantly in the 10-minute group, while there was no difference in 5-minute group. Central corneal thickness and thinnest corneal thickness did not differ, and endothelial cell density changes were within acceptable ranges in both groups before and after the surgery. Among keratometric values, keratometric astigmatism was significantly related to posttreatment corneal flattening effect in multivariate regression analysis.
Conclusions
A-CXL with continuous riboflavin application for 10 minutes is an effective and safe treatment for preventing keratoconus progression. In addition, higher corneal astigmatism showed greater posttreatment corneal flattening effect in successfully treated patients.
10.Enhancing Clerkship through a Ubiquitous Portfolio System: Design, Development, Implementation, and Dissemination
Bo Young YOON ; Younseok LEE ; Sejung KWON ; Ikseon CHOI ; Jong-Tae LEE
Korean Medical Education Review 2025;27(1):26-39
This paper describes the design, development, and implementation of a ubiquitous portfolio (u-portfolio) system aimed at enhancing clinical clerkship education at Inje University College of Medicine from 2016 to 2020. This developmental research employed involved a literature review of 69 papers on electronic portfolios (1990–2013), and as well as a series of focus group interviews and surveys with key stakeholders during the iterative design, evaluation, and revision process. The literature analysis revealed three main purposes of e-portfolios (learning, assessment, and showcase) and nine key elements for a multi-purpose e-portfolio (e.g., quality of student reflection, postgraduate continuous learning, and timely and frequent feedback). The system evolved from paper-based portfolios to address the standardization of students’ clerkship experiences across five teaching hospitals, incorporating competency-based education and enabling efficient data management to promote student learning, assessment, and feedback. Key challenges in transitioning from paper to electronic portfolios included infrastructure issues, user adaptation, and assessment standardization. The resulting u-portfolio system, which allowed the seamless integration of mobile devices, emphasized five core functions: enhanced real-time feedback, transparent evaluation with rubrics, improved reflection quality, real-time assessment and tracking, and mapping between learning and competency achievements. Initially implemented in the internal medicine clerkship in 2016, the system was gradually expanded to all core clerkships by 2018. The success of this system led to its adoption by 19 medical schools through a consortium organized by the Korea Association of Medical Colleges, with 31 schools now collaborating to enhance clerkships through the u-portfolio system.

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