1.Ratio of Skeletal Muscle Mass to Visceral Fat Area Is a Useful Marker for Assessing Left Ventricular Diastolic Dysfunction among Koreans with Preserved Ejection Fraction: An Analysis of the Random Forest Model
Jin Kyung OH ; Yuri SEO ; Wonmook HWANG ; Sami LEE ; Yong-Hoon YOON ; Kyupil KIM ; Hyun Woong PARK ; Jae-Hyung ROH ; Jae-Hwan LEE ; Minsu KIM
Journal of Obesity & Metabolic Syndrome 2025;34(1):54-64
Background:
Although the presence of both obesity and reduced muscle mass presents a dual metabolic burden and additively has a negative effect on a variety of cardiometabolic parameters, data regarding the associations between their combined effects and left ventricular diastolic function are limited. This study investigated the association between the ratio of skeletal muscle mass to visceral fat area (SVR) and left ventricular diastolic dysfunction (LVDD) in patients with preserved ejection fraction using random forest machine learning.
Methods:
In total, 1,070 participants with preserved left ventricular ejection fraction who underwent comprehensive health examinations, including transthoracic echocardiography and bioimpedance body composition analysis, were enrolled. SVR was calculated as an index of sarcopenic obesity by dividing the appendicular skeletal muscle mass by the visceral fat area.
Results:
In the random forest model, age and SVR were the most powerful predictors of LVDD. Multivariate logistic regression analysis demonstrated that older age (adjusted odds ratio [OR], 1.11; 95% confidence interval [CI], 1.07 to 1.15) and lower SVR (adjusted OR, 0.08; 95% CI, 0.01 to 0.57) were independent risk factors for LVDD.SVR showed a significant improvement in predictive performance and fair predictability for LVDD, with the highest area under the curve noted in both men and women, with statistical significance. In non-obese and metabolically healthy individuals, the lowest SVR tertile was associated with a greater risk of LVDD compared to the highest SVR tertile.
Conclusion
Decreased muscle mass and increased visceral fat were significantly associated with LVDD compared to obesity, body fat composition, and body muscle composition indices.
2.Comparison of tissue-based and plasma-based testing for EGFR mutation in non–small cell lung cancer patients
Yoon Kyung KANG ; Dong Hoon SHIN ; Joon Young PARK ; Chung Su HWANG ; Hyun Jung LEE ; Jung Hee LEE ; Jee Yeon KIM ; JooYoung NA
Journal of Pathology and Translational Medicine 2025;59(1):60-67
Background:
Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods.
Methods:
A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2.
Results:
All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%).
Conclusions
Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.
4.An erythrocyte macrocytosis by methotrexate is associated with early initiation of biologic or targeted synthetic agents in patients with rheumatoid arthritis
In-Woon BAEK ; Kyung-Su PARK ; Ki-Jo KIM
Journal of Rheumatic Diseases 2025;32(1):30-37
Objective:
An association between increased erythrocyte mean corpuscular volume (MCV) and treatment response in patients with inflammatory arthritis receiving methotrexate (MTX) has been reported. We investigated the frequency of red blood cell (RBC) macrocytosis and its clinical implications regarding the initiation of biological or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in patients starting MTX for rheumatoid arthritis (RA).
Methods:
RBC macrocytosis (MCV >100 fL) and clinical characteristics were retrospectively examined in 1,156 patients starting MTX for RA. Multivariable logistic regression analyses were performed to identify the independent predictors of RBC macrocytosis. The initiation of b/tsDMARDs was assessed using a multivariable Cox proportional hazards regression model.
Results:
RBC macrocytosis was observed in 21.6% of RA patients over 35 [8, 89] months following MTX initiation and was persistent in 63.6% of the patients during MTX treatment. Anemia coexisted in only 20.0% of the patients with RBC macrocytosis.The occurrence of RBC macrocytosis was independently associated with age, MTX dose, and concomitant use of sulfasalazine or leflunomide (all p<0.001). A higher dose of MTX and double- or triple-DMARDs therapy were more frequently used in the group with RBC macrocytosis than in the group with normal MCV. Patients experiencing RBC macrocytosis were more likely to use b/ tsDMARDs (hazard ratio: 1.45 [95% confidence interval: 1.13, 1.87], p=0.003).
Conclusion
RBC macrocytosis was possibly associated with the use of b/tsDMARD and could be a supplementary marker for assessing MTX resistance.
5.Risk of Biliary Tract and Pancreatic Cancer Following Obstructive Sleep Apnea Diagnosis: Analysis of a National Health Insurance Database
Marn Joon PARK ; Gyu Tae KIM ; Seo Jun KANG ; Kyung-Do HAN ; Jae Hoon CHO ; Ji Ho CHOI
Journal of Rhinology 2025;32(1):48-54
Background and Objectives:
Obstructive sleep apnea (OSA) has been associated with an increased risk of cancer in various organs. OSA is also linked to chronic inflammation in the biliary tract and pancreas, a well-established risk factor for carcinogenesis in these organs. However, its relationship with biliary tract and pancreatic cancers remains unclear and has been rarely investigated. Therefore, we aimed to evaluate whether OSA serves as an independent risk factor for these malignancies by analyzing a nationwide healthcare claims database in South Korea.
Methods:
A retrospective cohort study was conducted using the Korean National Health Insurance Service (KNHIS) database. Adults aged ≥20 years who were newly diagnosed with OSA (ICD-10: G47.30) between 2007 and 2014 were identified and propensity score-matched (1:5) with controls based on age, sex, and comorbidities. Individuals with pre-existing cancer diagnoses were excluded. The primary endpoints were the incidence of overall cancer, biliary tract cancer (C23–C24), and pancreatic cancer (C25). Cox proportional hazards regression models were used to calculate hazard ratios (HRs), adjusting for demographic and clinical factors.
Results:
A total of 1,191,444 individuals were included, comprising 198,574 patients diagnosed with OSA and 992,870 matched controls. OSA was associated with an increased overall cancer incidence (HR, 1.132; 95% confidence interval [CI], 1.097–1.169); however, it was not significantly associated with pancreatic cancer (HR, 0.941; 95% CI, 0.823–1.072) or biliary tract cancer (HR, 0.931; 95% CI, 0.751–1.142). Subgroup analyses stratified by sex and age revealed no statistically significant associations across these groups.
Conclusion
Our findings do not support OSA as an independent risk factor for biliary tract or pancreatic cancers.
6.Long-Term Incidence of Gastrointestinal Bleeding Following Ischemic Stroke
Jun Yup KIM ; Beom Joon KIM ; Jihoon KANG ; Do Yeon KIM ; Moon-Ku HAN ; Seong-Eun KIM ; Heeyoung LEE ; Jong-Moo PARK ; Kyusik KANG ; Soo Joo LEE ; Jae Guk KIM ; Jae-Kwan CHA ; Dae-Hyun KIM ; Tai Hwan PARK ; Kyungbok LEE ; Hong-Kyun PARK ; Yong-Jin CHO ; Keun-Sik HONG ; Kang-Ho CHOI ; Joon-Tae KIM ; Dong-Eog KIM ; Jay Chol CHOI ; Mi-Sun OH ; Kyung-Ho YU ; Byung-Chul LEE ; Kwang-Yeol PARK ; Ji Sung LEE ; Sujung JANG ; Jae Eun CHAE ; Juneyoung LEE ; Min-Surk KYE ; Philip B. GORELICK ; Hee-Joon BAE ;
Journal of Stroke 2025;27(1):102-112
Background:
and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes.
Methods:
We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data.
Results:
Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4.
Conclusion
Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.
7.Low-Density Lipoprotein Cholesterol Level, the Lower the Better? Analysis of Korean Patients in the Treat Stroke to Target Trial
Hanim KWON ; Jae-Chan RYU ; Jae-Kwan CHA ; Sang Min SUNG ; Tae-Jin SONG ; Kyung Bok LEE ; Eung-Gyu KIM ; Yong-Won KIM ; Ji Hoe HEO ; Man Seok PARK ; Kyusik KANG ; Byung-Chul LEE ; Keun-Sik HONG ; Oh Young BANG ; Jei KIM ; Jong S. KIM
Journal of Stroke 2025;27(2):228-236
Background:
and Purpose The Treat Stroke to Target (TST) was a randomized clinical trial involving French and Korean patients demonstrating that a lower low-density lipoprotein cholesterol (LDL-C, <70 mg/dL) target group (LT) experienced fewer cerebro-cardiovascular events than a higher target (90–110 mg/dL) group (HT). However, whether these results can be applied to Asian patients with different ischemic stroke subtypes remains unclear.
Methods:
Patients from 14 South Korean centers were analyzed separately. Patients with ischemic stroke or transient ischemic attack with evidence of atherosclerosis were randomized into LT and HT groups. The primary endpoint was a composite of ischemic stroke, myocardial infarction, coronary or cerebral revascularization, and cardiovascular death.
Results:
Among 712 enrolled patients, the mean LDL-C level was 71.0 mg/dL in 357 LT patients and 86.1 mg/dL in 355 HT patients. The primary endpoint occurred in 24 (6.7%) of LT and in 31 (8.7%) of HT group patients (adjusted hazard ratio [HR]=0.78; 95% confidence interval [CI]=0.45–1.33, P=0.353). Cardiovascular events alone occurred significantly less frequently in the LT than in the HT group (HR 0.26, 95% CI 0.09–0.80, P=0.019), whereas there were no significant differences in ischemic stroke events (HR 1.12, 95% CI 0.60–2.10, P=0.712). The benefit of LT was less apparent in patients with small vessel disease and intracranial atherosclerosis than in those with extracranial atherosclerosis.
Conclusion
In contrast to the French TST, the outcomes in Korean patients were neutral. Although LT was more effective in preventing cardiovascular diseases, it was not so in stroke prevention, probably attributed to the differences in stroke subtypes. Further studies are needed to elucidate the efficacy of statins and appropriate LDL-C targets in Asian patients with stroke.
8.Development of a Nutrition Management App to Mitigate Frailty in Aging Populations
Soyoung JUNG ; Hae Jin KANG ; Yoo Kyoung PARK
Journal of the Korean Dietetic Association 2025;31(1):13-23
Frailty is a condition marked by a progressive decline in physiological functioning due to aging, leading to increased disease morbidity and rising healthcare costs. Therefore, it is important to prevent frailty through proper management. Not only does a lack of physical activity contribute to frailty, but inadequate dietary intake, resulting from decreased appetite and malabsorption, is also a significant risk factor. This study aimed to develop a 16-week algorithm to assess the nutritional risks associated with frailty, provide personalized nutritional solutions, and manage frailty risk factors through continuous monitoring and periodic reassessment. A total of 20 indicators were selected to create a nutritional health score. The selected indicators encompassed nutritional risk factors for frailty, disease history, and hematological factors. Reassessments were designed to occur at four-week intervals to revise personalized management goals and adjust solutions. Metrics were prioritized to provide a personalized solution. A user-friendly monitoring system was developed that leveraged voice recognition technology to determine compliance. It is anticipated that the algorithm will serve several purposes. First, this outcome will allow us to help prevent and delay the onset of frailty by utilizing a mobile app. Second, it will reduce the time and economic costs associated with nutritional management. Finally, it will facilitate future professional counseling and monitoring.
10.Population attributable fraction as a key measure of primary cancer prevention strategy
Sohee PARK ; Yoon-Jung CHOI ; Sue Kyung PARK ; Hong Gwan SEO
Journal of the Korean Medical Association 2025;68(2):82-86
A fundamental objective of public health is to identify the causes of diseases and associated risk factors to develop effective prevention strategies. In this regard, the population attributable fraction (PAF) has become a key epidemiological measure for quantifying the proportion of disease incidence in a population attributable to specific risk factors.Current Concepts: The concept of PAF is widely applied in epidemiological and public health research, playing a crucial role in prioritizing disease prevention and management strategies. Estimating the PAF of cancer risk factors based on national data provides essential evidence for the formulation of government-led cancer control policies and prevention strategies. In particular, these estimates serve as critical indicators for evaluating cancer control programs and informing policy decisions. Given the variations in risk factor prevalence across different populations, it is crucial to estimate PAF using country-specific data to ensure the development of tailored and effective public health interventions.Discussion and Conclusion: This study underscores the importance of PAF as a foundational tool for evidencebased policymaking and highlights the need for periodic reassessment to enhance the effectiveness of cancer prevention and control efforts.

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