1.Sarcopenia: From Global Consensus to Korean Implementation — A Narrative Review and Standpoint
Geon Young JANG ; Sunghwan JI ; Heewon JUNG ; Ji Yeon BAEK ; Il-Young JANG ; Kyoung Min KIM ; Miji KIM ; Clara Yongjoo PARK ; Kwang-Pyo LEE ; Dongryeol RYU ; Sang Yoon LEE ; Ok Hee JEON ; Sunyoung KIM ;
Annals of Geriatric Medicine and Research 2026;30(1):3-17
Sarcopenia is a major geriatric syndrome characterized by progressive loss of muscle mass and strength, resulting in disability and mortality. This narrative review synthesizes international consensus recommendations and Korean evidence to guide context-specific sarcopenia management strategies. PubMed, Embase, Cochrane Library, and KoreaMed (January 2000–November 2025) were searched, focusing on randomized trials, meta-analyses, systematic reviews, clinical practice guidelines, and large observational studies. Global diagnostic frameworks have evolved from muscle mass-based definitions toward multidimensional models that incorporate muscle strength and physical performance. Exercise and nutrition remain the mainstay treatments, with resistance-based training and adequate protein intake. Currently, pharmacologic options with proven clinical benefit are limited. In Korea, growing evidence supports the effectiveness of community-based sarcopenia interventions, underscoring the need for standardized, integrated delivery models that bridge the fragmented healthcare system and enable sustainable implementation.
2.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.
3.Evaluation of the Performance of Advanced Large Language Models in Laboratory Medicine Using Residency Examinations
Kiwook JUNG ; Hyun Jin KIM ; Sunghwan SHIN ; Wookeun LEE ; Jun Hyung LEE ; Hee Sue PARK ; Qute CHOI
Annals of Laboratory Medicine 2026;46(3):327-337
Background:
Recent advancements in large language models (LLMs) have accelerated their integration into clinical domains, including laboratory medicine. The performance of LLMs in answering board-level laboratory medicine questions has not been comprehensively evaluated. Given the importance of diagnostic accuracy in this field, rigorous and objective evaluations of LLM capabilities are essential.
Methods:
We assessed 12 LLMs from OpenAI, Anthropic, and Google using 320 Korean Residency Examination questions (2021–2024) spanning six laboratory medicine subspecialties. Standardized prompts were provided via their application programming interfaces under deterministic settings (temperature = 0). Questions were administered thrice to assess response reproducibility. Outputs were compared with validated answers and analyzed for accuracy, reasoning quality, and error typology.
Results:
Google’s Gemini 2.0 Pro achieved the highest accuracy (80.0%), followed by OpenAI’s GPT-4.5 (77.2%) and Anthropic’s Claude 3.7 Sonnet (74.1%). Accuracy decreased as the difficulty of questions increased (78.0% for easy vs. 45.1% for challenging). Subspecialty performance varied. Al models underperformed on questions on transfusion medicine (mean accuracy: 38.8%), primarily because of limitations in domain-specific and regional knowledge representations. Incorrect answers primarily resulted from reasoning errors. Reproducibility exceeded 95% for most models; however, some residual non-determinism appeared even with greedy decoding (temperature = 0).
Conclusions
LLMs demonstrated substantial potential for integration into laboratory medicine, particularly in clinical chemistry and immunology. Performance inconsistencies (particularly for high-difficulty questions) and knowledge gaps (notably for transfusion medicine) highlight the necessity for further development—potentially including domain-specific fine-tuning and retrieval-augmented generation integration—and robust expert oversight before clinical application.
5.Associations between Education Years and Resting-state Functional Connectivity Modulated by APOE ε4 Carrier Status in Cognitively Normal Older Adults
Jiwon KIM ; Sunghwan KIM ; Yoo Hyun UM ; Sheng-Min WANG ; Regina EY KIM ; Yeong Sim CHOE ; Jiyeon LEE ; Donghyeon KIM ; Hyun Kook LIM ; Chang Uk LEE ; Dong Woo KANG
Clinical Psychopharmacology and Neuroscience 2024;22(1):169-181
Objective:
Cognitive reserve has emerged as a concept to explain the variable expression of clinical symptoms in the pathology of Alzheimer’s disease (AD). The association between years of education, a proxy of cognitive reserve, and resting-state functional connectivity (rFC), a representative intermediate phenotype, has not been explored in the preclinical phase, considering risk factors for AD. We aimed to evaluate whether the relationship between years of education and rFC in cognitively preserved older adults differs depending on amyloid-beta deposition and APOE ε4 carrier status as effect modifiers.
Methods:
A total of 121 participants underwent functional magnetic resonance imaging, [ 18F] flutemetamol positron emission tomography-computed tomography, APOE genotyping, and a neuropsychological battery. Potential interactions between years of education and AD risk factors for rFC of AD-vulnerable neural networks were assessed with wholebrain voxel-wise analysis.
Results:
We found a significant education years-by-APOE ε4 carrier status interaction for the rFC from the seed region of the central executive (CEN) and dorsal attention networks. Moreover, there was a significant interaction of rFC between right superior occipital gyrus and the CEN seed region by APOE ε4 carrier status for memory performances and overall cognitive function.
Conclusion
In preclinical APOE ε4 carriers, higher years of education were associated with higher rFC of the AD vulnerable network, but this contributed to lower cognitive function. These results contribute to a deeper understanding of the impact of cognitive reserve on sensitive functional intermediate phenotypic markers in the preclinical phase of AD.
6.Sarcopenia as the Mobility Phenotype of Aging: Clinical Implications
Sunghwan JI ; Hee-Won JUNG ; Ji Yeon BAEK ; Il-Young JANG ; Eunju LEE
Journal of Bone Metabolism 2024;31(1):1-12
Sarcopenia, which is characterized by an age-related decline in muscle mass and function, poses significant challenges to geriatric care. Its definition has evolved from muscle-specific criteria to include muscle mass, muscle function, and physical performance, recognizing sarcopenia as a physical frailty. Sarcopenia is associated with adverse outcomes, including mortality, falls, fractures, cognitive decline, and admission to long-term care facilities. Neuromechanical factors, protein-energy balance, and muscle protein synthesis-breakdown mechanisms contribute to its pathophysiology. The identification of sarcopenia involves screening tests and a comprehensive assessment of muscle mass, strength, and physical function. Clinical approaches aligned with the principles of comprehensive geriatric assessment prioritize patient-centered care. This assessment aids in identifying issues related to activities of daily living, cognition, mood, nutrition, and social support, alongside other aspects. The general approach to factors underlying muscle loss and functional decline in patients with sarcopenia includes managing chronic diseases and evaluating administered medications, with interventions including exercise and nutrition, as well as evolving pharmacological options. Ongoing research targeting pathways, such as myostatin-activin and exercise mimetics, holds promise for pharmacological interventions. In summary, sarcopenia requires a multifaceted approach, acknowledging its complex etiology and tailoring interventions to individual patient needs.
7.Development of Efficient Brain Age Estimation Method Based on Regional Brain Volume From Structural Magnetic Resonance Imaging
Sunghwan KIM ; Sheng-Min WANG ; Dong Woo KANG ; Yoo Hyun UM ; Hyeonsik YANG ; Hyunji LEE ; Regina EY KIM ; Donghyeon KIM ; Chang Uk LEE ; Hyun Kook LIM
Psychiatry Investigation 2024;21(1):37-43
Objective:
We aimed to create an efficient and valid predicting model which can estimate individuals’ brain age by quantifying their regional brain volumes.
Methods:
A total of 2,560 structural brain magnetic resonance imaging (MRI) scans, along with demographic and clinical data, were obtained. Pretrained deep-learning models were employed to automatically segment the MRI data, which enabled fast calculation of regional brain volumes. Brain age gaps for each subject were estimated using volumetric values from predefined 12 regions of interest (ROIs): bilateral frontal, parietal, occipital, and temporal lobes, as well as bilateral hippocampus and lateral ventricles. A larger weight was given to the ROIs having a larger mean volumetric difference between the cognitively unimpaired (CU) and cognitively impaired group including mild cognitive impairment (MCI), and dementia groups. The brain age was predicted by adding or subtracting the brain age gap to the chronological age according to the presence or absence of the atrophy region.
Results:
The study showed significant differences in brain age gaps among CU, MCI, and dementia groups. Furthermore, the brain age gaps exhibited significant correlations with education level and measures of cognitive function, including the clinical dementia rating sum-of-boxes and the Korean version of the Mini-Mental State Examination.
Conclusion
The brain age that we developed enabled fast and efficient brain age calculations, and it also reflected individual’s cognitive function and cognitive reserve. Thus, our study suggested that the brain age might be an important marker of brain health that can be used effectively in real clinical settings.
8.Effects of Serious Games in Older Adults With Mild Cognitive Impairment
Sheng-Min WANG ; Dong Woo KANG ; Yoo Hyun UM ; Sunghwan KIM ; Soyoung LEE ; Chang Uk LEE ; Hyun Kook LIM
Psychiatry Investigation 2024;21(5):449-456
Objective:
The rising prevalence of mild cognitive impairment (MCI) has spurred interest in innovative cognitive rehabilitation approaches, including serious games. This review summarizes randomized clinical trials (RCTs) exploring the impact of serious games on MCI patients.
Methods:
We conducted a comprehensive data search using key terms such as “gamification,” “digital therapy,” “cognition,” “mild cognitive impairment,” and “Alzheimer’s disease.” We exclusively considered published RCTs, excluding animal studies and basic research.
Results:
We identified eight RCTs. Four RCTs examined the effects of serious games using cognitive training for MCI patients. Notably, one study found that non-specific training (Nintendo Wii) significantly enhanced cognitive function and quality of life compared to cognition-specific computer training (CoTras). Among the remaining three RCTs, one specifically demonstrated that personalized serious game-based cognitive training yielded superior cognitive outcomes and reduced depressive symptoms. One RCT focused on serious games incorporating physical exercise, highlighting the effectiveness of kinetic-based exergaming in enhancing overall cognition. Three RCT focused on combined cognitive training and physical exercise. A double-blind RCT revealed that progressive resistance training or standalone physical exercise outperformed the combined approach in improving executive function and global cognition. Two additional RCTs reported positive outcomes, including improvements in cognitive function and electroencephalogram patterns associated with game-based interventions.
Conclusion
Serious games, whether focusing on cognitive training, physical exercise, or a combination of both, have potential to improve cognitive and functional outcomes in individuals with MCI. Further research and standardization of protocols are needed to better understand the full potential of serious games in MCI.
9.Risk Factors for Multiple Suicide Attempts in Adolescents From 10Years Suicide Repository
Sunghwan KIM ; Eun-Young YANG ; Kyoung Ho CHOI ; Hae Kook LEE ; Yong-Sil KWEON ; Kyoung-Uk LEE
Journal of Korean Medical Science 2024;39(46):e289-
Background:
While there are many studies on adolescents’ suicide attempts in the western countries, studies on adolescent suicide in South Korea are relatively scarce. We compared demographical and clinical variables between the first and multiple suicide attempters and examined potential risk factors predicting multiple suicide attempts.
Methods:
Two hundred forty-eight suicide attempters aged from 11 to 19 years old who visited emergency department of Uijeongbu St. Mary’s Hospital, South Korea were recruited and divided into two groups: first attempter (n = 139, 56%) and multiple attempter (n = 109, 44%). A psychiatric interview with the Brief Emergency Room Suicide Risk Assessment were administered to all participants, and univariate analyses to compare characteristics of the two group and a multivariable logistic regression analysis to predict multiple suicidal attempts were performed.
Results:
Our results showed multiple suicide attempters were mostly female (78%), more severe in psychopathology (e.g., higher rate of psychiatric family history, diagnosis of axis I history, history of major depressive disorder, higher feeling of hopelessness/helplessness) and suicidality (e.g., repetitive/severe/continuous suicide ideation, lower regret for suicide attempt). Moreover, multiple suicide attempters were lower in psychiatric resources, such as lower personal achievement, lower ability to control emotion, and less insight. Multivariate logistic regression analysis showed that suicide ideation severity (odds ratio [OR], 2.30;P = 0.004), past history of axis I diagnosis (especially major depressive disorder; OR, 2.55; P = 0.002), and the use of “cutting” (OR, 2.85; P = 0.001) predicted multiple suicide attempts.
Conclusion
The present study suggests that multiple suicide attempters tend to have more severe clinical profiles than the first suicide attempters. Intervention for depression and selfmutilation behavior of suicide attempters may be important in preventing multiple suicide attempts of adolescents.
10.Risk Factors for Multiple Suicide Attempts in Adolescents From 10Years Suicide Repository
Sunghwan KIM ; Eun-Young YANG ; Kyoung Ho CHOI ; Hae Kook LEE ; Yong-Sil KWEON ; Kyoung-Uk LEE
Journal of Korean Medical Science 2024;39(46):e289-
Background:
While there are many studies on adolescents’ suicide attempts in the western countries, studies on adolescent suicide in South Korea are relatively scarce. We compared demographical and clinical variables between the first and multiple suicide attempters and examined potential risk factors predicting multiple suicide attempts.
Methods:
Two hundred forty-eight suicide attempters aged from 11 to 19 years old who visited emergency department of Uijeongbu St. Mary’s Hospital, South Korea were recruited and divided into two groups: first attempter (n = 139, 56%) and multiple attempter (n = 109, 44%). A psychiatric interview with the Brief Emergency Room Suicide Risk Assessment were administered to all participants, and univariate analyses to compare characteristics of the two group and a multivariable logistic regression analysis to predict multiple suicidal attempts were performed.
Results:
Our results showed multiple suicide attempters were mostly female (78%), more severe in psychopathology (e.g., higher rate of psychiatric family history, diagnosis of axis I history, history of major depressive disorder, higher feeling of hopelessness/helplessness) and suicidality (e.g., repetitive/severe/continuous suicide ideation, lower regret for suicide attempt). Moreover, multiple suicide attempters were lower in psychiatric resources, such as lower personal achievement, lower ability to control emotion, and less insight. Multivariate logistic regression analysis showed that suicide ideation severity (odds ratio [OR], 2.30;P = 0.004), past history of axis I diagnosis (especially major depressive disorder; OR, 2.55; P = 0.002), and the use of “cutting” (OR, 2.85; P = 0.001) predicted multiple suicide attempts.
Conclusion
The present study suggests that multiple suicide attempters tend to have more severe clinical profiles than the first suicide attempters. Intervention for depression and selfmutilation behavior of suicide attempters may be important in preventing multiple suicide attempts of adolescents.

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