1.Osteoarticular Tuberculosis of the Metatarsophalangeal Joint Presented as a Chronic Cystic Mass
Soon-Hyuck LEE ; Dong-Hoon LEE ; Seok-Min HWANG
The Journal of the Korean Orthopaedic Association 2026;61(1):82-87
Osteoarticular tuberculosis is a rare form of extrapulmonary tuberculosis that typically involves weight-bearing joints such as the spine, pelvis, hip, and knee. Involvement of the foot is uncommon, with tuberculosis of the metatarsophalangeal joint being exceedingly rare. This paper reports a unique case of osteoarticular tuberculosis affecting the third metatarsophalangeal joint in a 79-year-old male, which has not been previously reported in Korea. Initially, the patient presented with a painless dorsal cyst over the joint that persisted for two years.As the lesion gradually enlarged and the symptoms developed, surgical excision was performed. A histopathological examination and molecular analysis of the resected tissue confirmed the diagnosis of osteoarticular tuberculosis. This case report highlights the diagnostic challenges posed by the nonspecific presentation of osteoarticular tuberculosis and emphasizes the need for clinical vigilance, particularly in regions with a low prevalence of tuberculosis.
2.Associated factors of osteoporosis and the impact of osteoporosis on all-cause mortality in incident hemodialysis older patients
Seunghye LEE ; Yoomee KANG ; Yu Ah HONG ; Sung Joon SHIN ; Soon Hyo KWON ; Sungjin CHUNG ; Young Youl HYUN ; Sang Heon SONG ; Jae Won YANG ; Won Min HWANG ; Jang-Hee CHO ; Kyung Don YOO ; In O SUN ; Gang-Jee KO ; Byung Chul YU ; Hyunsuk KIM ; Woo Yeong PARK ; Tae Won LEE ; Dong Jun PARK ; Eunjin BAE ;
Kidney Research and Clinical Practice 2026;45(1):110-119
Background:
With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality.
Methods:
We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis.
Results:
Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality.
Conclusion
We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.
3.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.
4.Beneficial Effects and Factors Associated With Provision of Breast Milk at Neonatal Intensive Care Unit Discharge to Very Low Birth Weight Infants: A Nationwide Cohort Study in Korea
Seung Hyun SHIN ; Hyun Seo KIM ; Da Min CHOI ; Soon-Young HWANG ; Eui Kyung CHOI
Journal of Korean Medical Science 2026;41(1):e20-
Background:
The incidence of preterm birth in Korea increased from 6.5% in 2013 to 9.7% in 2020. Very low birth weight (VLBW) infants, defined as those weighing < 1,500 g, are particularly vulnerable to numerous health risks. Breast milk provision reduces the incidence of complications in this vulnerable population. The objective of this study was to examine the rate and factors associated with breast milk provision at neonatal intensive care unit (NICU) discharge and to investigate its potential effects on growth and developmental outcomes at 18–24 months corrected age (CA).
Methods:
We conducted this cohort study using data from over 70 NICUs participating in the Korean Neonatal Network. VLBW infants born between January 2019 and December 2020 at a gestational age of 23 +0 to 31 +6 weeks were included. Discharge feeding types were analyzed of 2,490 infants, while follow-up assessments of growth and neurodevelopmental outcomes at 18–24 months of CA were available for 1,426 infants. Propensity score matching was used for comparative analysis.
Results:
The rate of breast milk provision at discharge among VLBW infants was 55.9% in 2019 and 56.5% in 2020. Factors that were positively associated with breast milk feeding included higher maternal education level and antenatal steroid use. In contrast, maternal hypertensive disorders, cesarean section, and severe neonatal morbidities (e.g., necrotizing enterocolitis) were correlated with lower breast milk feeding rates at the time of discharge.The provision of breast milk at discharge was not associated with a higher risk of suboptimal growth (below two standard deviations) compared to control infants at 18–24 months of CA. Neurodevelopmental assessments indicated that breast milk was associated with a reduced risk of developmental delay (adjusted odds ratio, 0.72; 95% confidence interval, 0.56–0.94) at follow-up.
Conclusion
Breast milk provision to VLBW infants at NICU discharge in Korea was comparable to that in other countries. This nationwide study highlights the critical role of breast milk in promoting the neurodevelopment of VLBW infants. Future efforts should focus on identifying the barriers to breast milk provision to improve health outcomes in vulnerable populations.
5.Predicting risk factors for waiting mortality in adult emergent living donor liver transplantation based on Korean national data
Sang Jin KIM ; Jongman KIM ; Kyunga KIM ; Soon-Young KIM ; Jung-Bun PARK ; Youngwon HWANG ; Dong-Hwan JUNG
Annals of Liver Transplantation 2025;5(2):107-114
Background:
Emergency living donor liver transplantation (e-LDLT) is crucial for patients experiencing acute liver failure, acute-on-chronic liver failure, or severe, life-threatening cirrhosis. The purpose of this study was to determine the risk factors that affect the death rate of patients who are waiting for e-LDLT by analyzing data on the Korean Network for Organ Sharing (KONOS).
Methods:
A retrospective examination of KONOS data was performed, encompassing consecutive e-LDLT applications from 2017 to 2021. Exclusions were made for pediatric patients. The data were classified into two distinct groups. Patients who died before getting e-LDLT were classified as Group 1 (n=38), while patients who spontaneously recovered without liver transplantation, non-emergency LDLT, or deceased donor liver transplantation more than 14 days following e-LDLT treatment were classified as Group 2 (n=30).
Results:
Significantly greater rates of pre-transplant critical care unit stay, pre-transplant ventilator support, or continuous renal replacement treatment were observed in Group 1 compared to Group 2. In comparison to Group 2, Group 1 exhibited notably lower serum albumin levels and higher model for end-stage liver disease (MELD) scores. Significantly, the MELD score increased by more than 10% for 3 days preceding to e-LDLT applications in Group 1 compared to Group 2. The multivariate analysis revealed that the only factor that affected the death of patients waiting for LDLT after e-LDLT applications was pre-transplant ventilator support.
Conclusion
The present study suggested that patients receiving mechanical ventilator support in the pre-transplant period should be approached cautiously when deciding on e-LDLT.
6.Living versus deceased donor liver transplantation in highly urgent patients using Korean national data
Jongman KIM ; Sang Jin KIM ; Kyunga KIM ; YoungRok CHOI ; Geun HONG ; Jun Yong PARK ; Young Seok HAN ; Nam-Joon YI ; Soon-Young KIM ; Jung-Bun PARK ; Youngwon HWANG ; Dong-Hwan JUNG
Annals of Liver Transplantation 2025;5(2):115-123
Background:
Deceased donor liver transplantation (DDLT) and living donor liver transplantation (LDLT) are employed to address highly urgent patients, including those with acute liver failure (ALF), acute-on-chronic liver failure (ACLF), or critical cirrhosis. This study compares outcomes between LDLT and DDLT patients with ALF, ACLF, or critical cirrhosis in highly urgent LDLT (HU-LDLT) applications.
Methods:
This study conducted a retrospective analysis of the Korean Network for Organ Sharing (KONOS) data, which included 391 consecutive HU-LDLT applications from 2017 to 2021.
Results:
The proportion of DDLT was 15.1% (n=59) within the cohort of HU-LDLT applications. The prevalence of hepatorenal syndrome, duration of pre-transplant intensive care unit (ICU) care, incidence of pre-transplant continuous renal replacement therapy, and median model for end-stage liver disease scores were significantly greater and prolonged in DDLT patients compared to LDLT patients. Statistical analysis revealed no significant differences in postoperative complications or overall survival between the two groups. In the multivariate analysis, only pre-transplant ventilator care emerged as a significant predisposing factor for mortality.
Conclusion
The present study indicates that LDLT is a viable option, yielding comparable perioperative and long-term outcomes to DDLT for HU patients, which can encourage living liver donation to overcome organ shortages in HU patients.
7.Sex Differences in Procedural Characteristics and Clinical Outcomes Among Patients Undergoing Bifurcation PCI
Hyun Jin AHN ; Francesco BRUNO ; Jeehoon KANG ; Doyeon HWANG ; Han-Mo YANG ; Jung-Kyu HAN ; Leonardo De LUCA ; Ovidio de FILIPPO ; Alessio MATTESINI ; Kyung Woo PARK ; Alessandra TRUFFA ; Wojciech WANHA ; Young Bin SONG ; Sebastiano GILI ; Woo Jung CHUN ; Gerard HELFT ; Seung-Ho HUR ; Bernardo CORTESE ; Seung Hwan HAN ; Javier ESCANED ; Alaide CHIEFFO ; Ki Hong CHOI ; Guglielmo GALLONE ; Joon-Hyung DOH ; Gaetano De FERRARI ; Soon-Jun HONG ; Giorgio QUADRI ; Chang-Wook NAM ; Hyeon-Cheol GWON ; Hyo-Soo KIM ; Fabrizio D’ASCENZO ; Bon-Kwon KOO
Korean Circulation Journal 2025;55(1):5-16
Background and Objectives:
The risk profiles, procedural characteristics, and clinical outcomes for women undergoing bifurcation percutaneous coronary intervention (PCI) are not well defined compared to those in men.
Methods:
COronary BIfurcation Stenting III (COBIS III) is a multicenter, real-world registry of 2,648 patients with bifurcation lesions treated with second-generation drug-eluting stents.We compared the angiographic and procedural characteristics and clinical outcomes based on sex. The primary outcome was 5-year target lesion failure (TLF), a composite of cardiac death, myocardial infarction, and target lesion revascularization.
Results:
Women (n=635, 24%) were older, had hypertension and diabetes more often, and had smaller main vessel and side branch reference diameters than men. The pre- and post-PCI angiographic percentage diameter stenoses of the main vessel and side branch were comparable between women and men. There were no differences in procedural characteristics between the sexes. Women and men had a similar risk of TLF (6.3% vs. 7.1%, p=0.63) as well as its individual components and sex was not an independent predictor of TLF. This finding was consistent in the left main and 2 stenting subgroups.
Conclusions
In patients undergoing bifurcation PCI, sex was not an independent predictor of adverse outcome.
8.Low Serum Creatinine as Well as High Serum Creatinine Is Associated with Prognosis of Patients with Cancer in End-of-Life
Yoo Jeong LEE ; Soon-Young HWANG ; Su Hyun KIM ; Youn Seon CHOI
Korean Journal of Family Medicine 2025;46(2):70-76
Background:
The prognosis of end-of-life patients is challenging, and clinicians have attempted to predict survival more accurately. High serum creatinine (sCr) levels are associated with lower survival rates in patients with various cancers; however, low sCr levels are commonly expected in patients with terminal cancer because of muscle wasting and malnutrition. Therefore, we investigated the prevalence of low and high sCr levels and their association with survival duration in patients with terminal cancer in a palliative care unit.
Methods:
We analyzed the medical records of 280 patients admitted to a palliative care unit. Patients were divided into low (<0.5 mg/dL), normal (0.5–1.2 mg/dL), and high (>1.2 mg/dL) sCr groups. Kaplan-Meier survival curves using sCr levels were plotted and compared using the log-rank test. Using stepwise selection, a multivariable Cox proportional hazards model was used to identify the significant prognostic factors.
Results:
The median survival durations in the high-, low-, and normal-sCr groups were 9.57 days, 22.26 days, and 27.51 days, respectively. Multivariable Cox proportional hazard model identified that males (hazard ratio [HR], 1.81; 95% confidence interval [CI], 1.16–2.85), poor performance status (HR, 3.43; 95% CI, 1.12–10.54), total parenteral nutrition use (HR, 1.84; 95% CI, 1.09–3.1), high sCr (HR, 2.74; 95% CI, 1.52–4.94), and low sCr (HR, 1.22; 95% CI, 1.07–1.43) were significantly associated with a shorter survival time.
Conclusion
Low and high serum creatinine levels were significantly associated with poor survival in patients with cancer at the end-of-life stage. Therefore, readily available and simple biomarkers may help plan advanced care in palliative care settings.
9.Development and Application of New Risk-Adjustment Models to Improve the Current Model for Hospital Standardized Mortality Ratio in South Korea
Hyeki PARK ; Ji-Sook CHOI ; Min Sun SHIN ; Soomin KIM ; Hyekyoung KIM ; Nahyeong IM ; Soon Joo PARK ; Donggyo SHIN ; Youngmi SONG ; Yunjung CHO ; Hyunmi JOO ; Hyeryeon HONG ; Yong-Hwa HWANG ; Choon-Seon PARK
Yonsei Medical Journal 2025;66(3):179-186
Purpose:
This study assessed the validity of the hospital standardized mortality ratio (HSMR) risk-adjusted model by comparing models that include clinical information and the current model based on administrative information in South Korea.
Materials and Methods:
The data of 53976 inpatients were analyzed. The current HSMR risk-adjusted model (Model 1) adjusts for sex, age, health coverage, emergency hospitalization status, main diagnosis, surgery status, and Charlson Comorbidity Index (CCI) using administrative data. As candidate variables, among clinical information, the American Society of Anesthesiologists score, Acute Physiology and Chronic Health Evaluation (APACHE) II, Simplified Acute Physiology Score (SAPS) 3, present on admission CCI, and cancer stage were collected. Surgery status, intensive care in the intensive care unit, and CCI were selected as proxy variables among administrative data. In-hospital death was defined as the dependent variable, and a logistic regression analysis was performed. The statistical performance of each model was compared using C-index values.
Results:
There was a strong correlation between variables in the administrative data and those in the medical records. The C-index of the existing model (Model 1) was 0.785; Model 2, which included all clinical data, had a higher C-index of 0.857. In Model 4, in which APACHE II and SAPS 3 were replaced with variables recorded in the administrative data from Model 2, the C-index further increased to 0.863.
Conclusion
The HSMR assessment model improved when clinical data were adjusted. Simultaneously, the validity of the evaluation method could be secured even if some of the clinical information was replaced with the information in the administrative data.
10.Mock communities to assess biases in nextgeneration sequencing of bacterial species representation
Younjee HWANG ; Ju Yeong KIM ; Se Il KIM ; Ji Yeon SUNG ; Hye Su MOON ; Tai-Soon YONG ; Ki Ho HONG ; Hyukmin LEE ; Dongeun YONG
Annals of Clinical Microbiology 2025;28(1):3-
Background:
The 16S rRNA-targeted next-generation sequencing (NGS) has been widely used as the primary tool for microbiome analysis. However, whether the sequenced microbial diversity absolutely represents the original sample composition remains unclear. This study aimed to evaluate whether 16S rRNA gene-targeted NGS accurately captures bacterial community composition.
Methods:
Mock communities were constructed using equal amounts of DNA from 18 bacterial strains in three formats: genomic DNA, recombinant plasmids, and polymerase chain reaction (PCR) templates. The V3V4 region of the 16S rRNA gene was amplified and sequenced using the Illumina MiSeq.
Results:
Data regression analysis revealed that the recombinant plasmid produced more accurate and precise correlation curve than that by the gDNA and PCR products, with a slope closest to 1 (1.0082) and the highest R² value (0.9975). Despite the same input amount of bacterial DNA, the NGS read distribution varied across all three mock communities. Using multiple regression analysis, we found that the guanine-cytosine (GC) content of the V3V4 region, 16S rRNA gene, size of gDNA, and copy number of 16S rRNA were significantly associated with the NGS output of each bacterial species.
Conclusion
This study demonstrated that recombinant plasmids are the preferred option for quality control and that NGS output is biased owing to certain bacterial characteristics, such as %GC content, gDNA size, and 16S rRNA gene copy number. Further research is required to develop a system that compensates for NGS process biases using mock communities.

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