2.Non-Linear Association Between Physical Activities and Type 2Diabetes in 2.4 Million Korean Population, 2009–2022: A Nationwide Representative Study
Wonwoo JANG ; Seokjun KIM ; Yejun SON ; Soeun KIM ; Hayeon LEE ; Jaeyu PARK ; Kyeongmin LEE ; Jiseung KANG ; Damiano PIZZOL ; Jiyoung HWANG ; Sang Youl RHEE ; Dong Keon YON
Journal of Korean Medical Science 2025;40(12):e42-
Background:
Although excessive physical activity (PA) does not always confer additional health benefits, there is a paucity of studies that have quantitatively examined the doseresponse relationship between PA and type 2 diabetes. Therefore, this study investigated the relationship between the type 2 diabetes prevalence and intensity, frequency, and metabolic equivalent of task (MET) score of PA in a large population sample.
Methods:
We conducted a nationwide cross-sectional analysis examining sociodemographic variables, PA habits, and type 2 diabetes prevalence in 2,428,448 participants included in the Korea Community Health Survey. The non-linear association between MET score and odds ratios (ORs) for type 2 diabetes prevalence was plotted using a weighted generalized additive model. Categorical analysis was used to examine the joint association of moderate-intensity PA (MPA) and vigorous-intensity PA (VPA), and the influence of PA frequency.
Results:
MET score and diabetes prevalence revealed a non-linear association with the nadir at 1,028 MET-min/week, beyond which ORs increased with additional PA. Joint analysis of MPA and VPA showed the lowest OR of 0.79 (95% confidence interval, 0.75–0.84) for those engaging in 300–600 MET-min/week of MPA and > 600 MET-min/week of VPA concurrently, corresponding with World Health Organization recommendations. Additionally, both “weekend warriors” and “regularly active” individuals showed lower ORs compared to the inactive, although no significant difference was noted between the active groups.
Conclusion
In a large South Korean sample, higher PA is not always associated with a lower prevalence of type 2 diabetes, as the association follows a non-linear pattern; differences existed across sociodemographic variables. Considering the joint association, an adequate combination of MPA and VPA is recommended. The frequency of PA does not significantly influence the type 2 diabetes prevalence.
3.Non-Linear Association Between Physical Activities and Type 2Diabetes in 2.4 Million Korean Population, 2009–2022: A Nationwide Representative Study
Wonwoo JANG ; Seokjun KIM ; Yejun SON ; Soeun KIM ; Hayeon LEE ; Jaeyu PARK ; Kyeongmin LEE ; Jiseung KANG ; Damiano PIZZOL ; Jiyoung HWANG ; Sang Youl RHEE ; Dong Keon YON
Journal of Korean Medical Science 2025;40(12):e42-
Background:
Although excessive physical activity (PA) does not always confer additional health benefits, there is a paucity of studies that have quantitatively examined the doseresponse relationship between PA and type 2 diabetes. Therefore, this study investigated the relationship between the type 2 diabetes prevalence and intensity, frequency, and metabolic equivalent of task (MET) score of PA in a large population sample.
Methods:
We conducted a nationwide cross-sectional analysis examining sociodemographic variables, PA habits, and type 2 diabetes prevalence in 2,428,448 participants included in the Korea Community Health Survey. The non-linear association between MET score and odds ratios (ORs) for type 2 diabetes prevalence was plotted using a weighted generalized additive model. Categorical analysis was used to examine the joint association of moderate-intensity PA (MPA) and vigorous-intensity PA (VPA), and the influence of PA frequency.
Results:
MET score and diabetes prevalence revealed a non-linear association with the nadir at 1,028 MET-min/week, beyond which ORs increased with additional PA. Joint analysis of MPA and VPA showed the lowest OR of 0.79 (95% confidence interval, 0.75–0.84) for those engaging in 300–600 MET-min/week of MPA and > 600 MET-min/week of VPA concurrently, corresponding with World Health Organization recommendations. Additionally, both “weekend warriors” and “regularly active” individuals showed lower ORs compared to the inactive, although no significant difference was noted between the active groups.
Conclusion
In a large South Korean sample, higher PA is not always associated with a lower prevalence of type 2 diabetes, as the association follows a non-linear pattern; differences existed across sociodemographic variables. Considering the joint association, an adequate combination of MPA and VPA is recommended. The frequency of PA does not significantly influence the type 2 diabetes prevalence.
4.Non-Linear Association Between Physical Activities and Type 2Diabetes in 2.4 Million Korean Population, 2009–2022: A Nationwide Representative Study
Wonwoo JANG ; Seokjun KIM ; Yejun SON ; Soeun KIM ; Hayeon LEE ; Jaeyu PARK ; Kyeongmin LEE ; Jiseung KANG ; Damiano PIZZOL ; Jiyoung HWANG ; Sang Youl RHEE ; Dong Keon YON
Journal of Korean Medical Science 2025;40(12):e42-
Background:
Although excessive physical activity (PA) does not always confer additional health benefits, there is a paucity of studies that have quantitatively examined the doseresponse relationship between PA and type 2 diabetes. Therefore, this study investigated the relationship between the type 2 diabetes prevalence and intensity, frequency, and metabolic equivalent of task (MET) score of PA in a large population sample.
Methods:
We conducted a nationwide cross-sectional analysis examining sociodemographic variables, PA habits, and type 2 diabetes prevalence in 2,428,448 participants included in the Korea Community Health Survey. The non-linear association between MET score and odds ratios (ORs) for type 2 diabetes prevalence was plotted using a weighted generalized additive model. Categorical analysis was used to examine the joint association of moderate-intensity PA (MPA) and vigorous-intensity PA (VPA), and the influence of PA frequency.
Results:
MET score and diabetes prevalence revealed a non-linear association with the nadir at 1,028 MET-min/week, beyond which ORs increased with additional PA. Joint analysis of MPA and VPA showed the lowest OR of 0.79 (95% confidence interval, 0.75–0.84) for those engaging in 300–600 MET-min/week of MPA and > 600 MET-min/week of VPA concurrently, corresponding with World Health Organization recommendations. Additionally, both “weekend warriors” and “regularly active” individuals showed lower ORs compared to the inactive, although no significant difference was noted between the active groups.
Conclusion
In a large South Korean sample, higher PA is not always associated with a lower prevalence of type 2 diabetes, as the association follows a non-linear pattern; differences existed across sociodemographic variables. Considering the joint association, an adequate combination of MPA and VPA is recommended. The frequency of PA does not significantly influence the type 2 diabetes prevalence.
5.Non-Linear Association Between Physical Activities and Type 2Diabetes in 2.4 Million Korean Population, 2009–2022: A Nationwide Representative Study
Wonwoo JANG ; Seokjun KIM ; Yejun SON ; Soeun KIM ; Hayeon LEE ; Jaeyu PARK ; Kyeongmin LEE ; Jiseung KANG ; Damiano PIZZOL ; Jiyoung HWANG ; Sang Youl RHEE ; Dong Keon YON
Journal of Korean Medical Science 2025;40(12):e42-
Background:
Although excessive physical activity (PA) does not always confer additional health benefits, there is a paucity of studies that have quantitatively examined the doseresponse relationship between PA and type 2 diabetes. Therefore, this study investigated the relationship between the type 2 diabetes prevalence and intensity, frequency, and metabolic equivalent of task (MET) score of PA in a large population sample.
Methods:
We conducted a nationwide cross-sectional analysis examining sociodemographic variables, PA habits, and type 2 diabetes prevalence in 2,428,448 participants included in the Korea Community Health Survey. The non-linear association between MET score and odds ratios (ORs) for type 2 diabetes prevalence was plotted using a weighted generalized additive model. Categorical analysis was used to examine the joint association of moderate-intensity PA (MPA) and vigorous-intensity PA (VPA), and the influence of PA frequency.
Results:
MET score and diabetes prevalence revealed a non-linear association with the nadir at 1,028 MET-min/week, beyond which ORs increased with additional PA. Joint analysis of MPA and VPA showed the lowest OR of 0.79 (95% confidence interval, 0.75–0.84) for those engaging in 300–600 MET-min/week of MPA and > 600 MET-min/week of VPA concurrently, corresponding with World Health Organization recommendations. Additionally, both “weekend warriors” and “regularly active” individuals showed lower ORs compared to the inactive, although no significant difference was noted between the active groups.
Conclusion
In a large South Korean sample, higher PA is not always associated with a lower prevalence of type 2 diabetes, as the association follows a non-linear pattern; differences existed across sociodemographic variables. Considering the joint association, an adequate combination of MPA and VPA is recommended. The frequency of PA does not significantly influence the type 2 diabetes prevalence.
6.National Trends in Influenza Vaccination Rates in South Korea Before and During the COVID-19 Pandemic, 2011-2022.
Kyeongeun KIM ; Kyeongmin LEE ; Yejun SON ; Seoyoung PARK ; Raphael UDEH ; Jiseung KANG ; Hayeon LEE ; Soeun KIM ; Jaeyu PARK ; Hyeon Jin KIM ; Damiano PIZZOL ; Lee SMITH ; Jiyoung HWANG ; Dong Keon YON
Biomedical and Environmental Sciences 2025;38(9):1044-1057
OBJECTIVE:
Despite the global decrease in influenza infections during the coronavirus disease 2019 (COVID-19) pandemic, seasonal influenza remains a significant health issue. South Korea, known for its robust pandemic response and high influenza vaccination rates, offers a unique context for examining changes in vaccination trends during the pandemic. Using nationally representative data, we aimed to understand the impact of the pandemic on influenza vaccination behavior over a 12-year period and to identify vulnerable groups.
METHODS:
We analyzed influenza vaccination rates in South Korea between 2011-2022, focusing on pandemic-related impacts. The data of 2,426,139 adults (≥ 19 years) from the Korea Community Health Survey were used to assess demographic and sociological factors influencing vaccination behaviors.
RESULTS:
We observed an increase in influenza vaccination rates during the pre-COVID-19 period from 2011-2013 (weighted prevalence: 46.68% [95% confidence interval ( CI): 46.55-46.82]) to 2017-2019 (weighted prevalence: 52.50% [95% CI: 52.38-52.63]). However, a significant decline was observed in 2022, the late-COVID-19 pandemic period (weighted prevalence: 55.78% [95% CI: 55.56-56.01]), compared with the mid-pandemic period in 2021 (weighted prevalence: 59.12% [95% CI: 58.91-59.32]), particularly among populations traditionally prioritized for influenza vaccination, including older adults (≥ 65 years) and patients with chronic diseases and low educational and income levels.
CONCLUSION
The influenza vaccination rate in South Korea was significantly affected by the COVID-19 pandemic, showing a notable decrease among vulnerable demographic groups. This suggests the need for targeted public health strategies to address vaccine hesitancy and improve vaccination rates, particularly among high-risk populations.
Humans
;
Republic of Korea/epidemiology*
;
COVID-19/epidemiology*
;
Adult
;
Middle Aged
;
Influenza Vaccines/administration & dosage*
;
Male
;
Female
;
Influenza, Human/epidemiology*
;
Aged
;
Vaccination/statistics & numerical data*
;
Young Adult
;
Pandemics
;
SARS-CoV-2
7.Advanced Hepatocellular Carcinoma Missed on Ultrasonography: A Case Report
Tom RYU ; Jae Young JANG ; Yon Hee KIM ; Young CHANG ; Soung Won JEONG
Clinical Ultrasound 2025;10(2):114-118
We report the case of a 59-year-old man with chronic hepatitis B–related liver cirrhosis who developed diffuse hepatocellular carcinoma (HCC) with portal vein thrombosis (PVT) within only six months despite ongoing antiviral therapy. Importantly, initial surveillance ultrasonography failed to detect any definite malignant lesions, and serum alpha-fetoprotein remained within normal range, suggesting potential limitations for ultrasound in identifying early or infiltrative forms of HCC. At the 6-month follow-up, new-onset PVT was found incidentally on ultrasound, which became the key diagnostic clue leading to the detection of infiltrative HCC. Transarterial chemoembolization and radiation therapy, followed by splenic artery embolization for thrombocytopenia management were performed. Subsequently, a multidisciplinary approach enabled curative left hemihepatectomy with portal thrombectomy, which was successful. This case highlights that even in regular surveillance programs, HCC may be missed on initial ultrasonography, emphasizing the need for careful assessment of subtle vascular or parenchymal changes and the importance of integrating complementary imaging modalities.
8.Genetic Landscape and Clinical Manifestations of Multiple Endocrine Neoplasia Type 1 in a Korean Cohort: A Multicenter Retrospective Analysis
Boram KIM ; Seung Hun LEE ; Chang Ho AHN ; Han Na JANG ; Sung Im CHO ; Jee-Soo LEE ; Yu-Mi LEE ; Su-Jin KIM ; Tae-Yon SUNG ; Kyu Eun LEE ; Woochang LEE ; Jung-Min KOH ; Moon-Woo SEONG ; Jung Hee KIM
Endocrinology and Metabolism 2024;39(6):956-964
Background:
Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by tumors in multiple endocrine organs, caused by variants in the MEN1 gene. This study analyzed the clinical and genetic features of MEN1 in a Korean cohort, identifying prevalent manifestations and genetic variants, including novel variants.
Methods:
This multicenter retrospective study reviewed the medical records of 117 MEN1 patients treated at three tertiary centers in Korea between January 2012 and September 2022. Patient demographics, tumor manifestations, outcomes, and MEN1 genetic testing results were collected. Variants were classified using American College of Medical Genetics and Genomics (ACMG) and French Oncogenetics Network of Neuroendocrine Tumors propositions (TENGEN) guidelines.
Results:
A total of 117 patients were enrolled, including 55 familial cases, with a mean age at diagnosis of 37.4±15.3 years. Primary hyperparathyroidism was identified as the most common presentation (84.6%). The prevalence of gastroenteropancreatic neuroendocrine tumor and pituitary neuroendocrine tumor (PitNET) was 77.8% (n=91) and 56.4% (n=66), respectively. Genetic testing revealed 61 distinct MEN1 variants in 101 patients, with 18 being novel. Four variants were reclassified according to the TENGEN guidelines. Patients with truncating variants (n=72) exhibited a higher prevalence of PitNETs compared to those with non-truncating variants (n=25) (59.7% vs. 36.0%, P=0.040).
Conclusion
The association between truncating variants and an increased prevalence of PitNETs in MEN1 underscores the importance of genetic characterization in guiding the clinical management of this disease. Our study sheds light on the clinical and genetic characteristics of MEN1 among the Korean population.
9.Characteristics of Pediatric Ulcerative Colitis at Diagnosis in Korea: Results From a Multicenter, Registry-Based, Inception Cohort Study
Jin Gyu LIM ; Ben KANG ; Seak Hee OH ; Eell RYOO ; Yu Bin KIM ; Yon Ho CHOE ; Yeoun Joo LEE ; Minsoo SHIN ; Hye Ran YANG ; Soon Chul KIM ; Yoo Min LEE ; Hong KOH ; Ji Sook PARK ; So Yoon CHOI ; Su Jin JEONG ; Yoon LEE ; Ju Young CHANG ; Tae Hyeong KIM ; Jung Ok SHIM ; Jin Soo MOON
Journal of Korean Medical Science 2024;39(49):e303-
Background:
We aimed to investigate the characteristics of pediatric ulcerative colitis (UC) at diagnosis in Korea.
Methods:
This was a multicenter, registry-based, inception cohort study conducted in Korea between 2021 and 2023. Children and adolescents newly diagnosed with UC < 18 years were included. Baseline clinicodemographics, results from laboratory, endoscopic exams, and Paris classification factors were collected, and associations between factors at diagnosis were investigated.
Results:
A total 205 patients with UC were included. Male-to-female ratio was 1.59:1, and the median age at diagnosis was 14.7 years (interquartile range 11.9–16.2). Disease extent of E1 comprised 12.2% (25/205), E2 24.9% (51/205), E3 11.2% (23/205), and E4 51.7% (106/205) of the patients. S1 comprised 13.7% (28/205) of the patients. The proportion of patients with a disease severity of S1 was significantly higher in patients with E4 compared to the other groups (E1: 0% vs. E2: 2% vs. E3: 0% vs. E4: 24.5%, P < 0.001). Significant differences between disease extent groups were also observed in Pediatric Ulcerative Colitis Activity Index (median 25 vs. 35 vs. 40 vs. 45, respectively, P < 0.001), hemoglobin (median 13.5 vs.13.2 vs. 11.6 vs. 11.4 g/dL, respectively, P < 0.001), platelet count (median 301 vs. 324 vs. 372 vs. 377 × 103 /μL, respectively, P = 0.001), C-reactive protein (median 0.05 vs. 0.10 vs. 0.17 vs. 0.38 mg/dL, respectively, P < 0.001), and Ulcerative Colitis Endoscopic Index of Severity (median 4 vs. 4 vs. 4 vs. 5, respectively, P = 0.006). No significant differences were observed in factors between groups divided according to sex and diagnosis age.
Conclusion
This study represents the largest multicenter pediatric inflammatory bowel disease cohort in Korea. Disease severity was associated with disease extent in pediatric patients with UC at diagnosis.
10.Characteristics of Pediatric Ulcerative Colitis at Diagnosis in Korea: Results From a Multicenter, Registry-Based, Inception Cohort Study
Jin Gyu LIM ; Ben KANG ; Seak Hee OH ; Eell RYOO ; Yu Bin KIM ; Yon Ho CHOE ; Yeoun Joo LEE ; Minsoo SHIN ; Hye Ran YANG ; Soon Chul KIM ; Yoo Min LEE ; Hong KOH ; Ji Sook PARK ; So Yoon CHOI ; Su Jin JEONG ; Yoon LEE ; Ju Young CHANG ; Tae Hyeong KIM ; Jung Ok SHIM ; Jin Soo MOON
Journal of Korean Medical Science 2024;39(49):e303-
Background:
We aimed to investigate the characteristics of pediatric ulcerative colitis (UC) at diagnosis in Korea.
Methods:
This was a multicenter, registry-based, inception cohort study conducted in Korea between 2021 and 2023. Children and adolescents newly diagnosed with UC < 18 years were included. Baseline clinicodemographics, results from laboratory, endoscopic exams, and Paris classification factors were collected, and associations between factors at diagnosis were investigated.
Results:
A total 205 patients with UC were included. Male-to-female ratio was 1.59:1, and the median age at diagnosis was 14.7 years (interquartile range 11.9–16.2). Disease extent of E1 comprised 12.2% (25/205), E2 24.9% (51/205), E3 11.2% (23/205), and E4 51.7% (106/205) of the patients. S1 comprised 13.7% (28/205) of the patients. The proportion of patients with a disease severity of S1 was significantly higher in patients with E4 compared to the other groups (E1: 0% vs. E2: 2% vs. E3: 0% vs. E4: 24.5%, P < 0.001). Significant differences between disease extent groups were also observed in Pediatric Ulcerative Colitis Activity Index (median 25 vs. 35 vs. 40 vs. 45, respectively, P < 0.001), hemoglobin (median 13.5 vs.13.2 vs. 11.6 vs. 11.4 g/dL, respectively, P < 0.001), platelet count (median 301 vs. 324 vs. 372 vs. 377 × 103 /μL, respectively, P = 0.001), C-reactive protein (median 0.05 vs. 0.10 vs. 0.17 vs. 0.38 mg/dL, respectively, P < 0.001), and Ulcerative Colitis Endoscopic Index of Severity (median 4 vs. 4 vs. 4 vs. 5, respectively, P = 0.006). No significant differences were observed in factors between groups divided according to sex and diagnosis age.
Conclusion
This study represents the largest multicenter pediatric inflammatory bowel disease cohort in Korea. Disease severity was associated with disease extent in pediatric patients with UC at diagnosis.

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