1.Association between relative handgrip strength and glycemic control among male automobile manufacturing workers using vibration tools in South Korea
Dong-Jae SEO ; Hyun Joong KIM ; Yongjin KIM ; Jaewon MUN ; Jong-Han LEEM ; Shin-Goo PARK ; Dong-Wook LEE ; Hwan-Cheol KIM
Annals of Occupational and Environmental Medicine 2026;38(1):e14-
Background:
Although the association between handgrip strength and glycemic control has been reported, studies conducted exclusively within specific occupational groups remain limited. To explore the association between handgrip strength and metabolic health in industrial settings, this study examined the relationship between relative handgrip strength and glycated hemoglobin (HbA1c) among male automobile manufacturing workers using vibration tools in South Korea.
Methods:
Using 66,212 occupational health examination records collected at Inha University Hospital between January 2024 and April 2025, a total of 3,365 workers with HbA1c and handgrip strength measurements were identified. After excluding duplicates (n = 1,536), female workers (n = 2), and records without Hb and estimated glomerular filtration rate, 1,823 male participants were included in the final analysis. Relative handgrip strength was calculated as the maximum value of bilateral grip strength divided by body mass index. Multiple linear regression analyses were conducted to assess the association between relative handgrip strength and HbA1c, adjusting for age, smoking status, alcohol consumption, current hypertension, current dyslipidemia, current hypoglycemic-agents use, family diabetes history, leisure-time physical activity, and resistance exercise.
Results:
Relative handgrip strength was inversely associated with HbA1c levels (B: –0.060; 95% confidence interval [CI]: −0.081 to −0.039; p < 0.001). The association was strongest among normoglycemic participants (B: −0.185; 95% CI: −0.305 to −0.065; p = 0.003). Effect size was reduced but significantly associated among individuals with prediabetes (B: −0.115; 95% CI: −0.180 to −0.050; p < 0.001) and further attenuated to a borderline significance in individuals with diabetes (B: −0.023; 95% CI: −0.050 to 0.003; p = 0.082). These findings indicate that greater muscle strength relative to body size is related to better glycemic control.
Conclusions
Handgrip strength was associated with HbA1c levels in industrial workers. This study suggests that handgrip strength may provide complementary information on metabolic health in occupational settings.
2.3-Dimensional reconstruction reveals frequent intraluminal growth of submucosal veins in surgically resected pT1 colorectal cancers
Jihyun PARK ; Mi-Ju KIM ; Yeon Wook KIM ; Byong-Wook LEE ; Junyoung SHIN ; Jinho SHIN ; Chan-Gi PACK ; Dong-Hoon YANG ; Jihun KIM ; In Ja PARK ; Ralph H. HRUBAN ; Seung-Mo HONG
Journal of Pathology and Translational Medicine 2026;60(2):246-262
Although venous invasion (VI) is associated with distant metastasis and observed in >50% of pT2–4 colorectal cancers (CRCs), the role of VI in pT1 CRCs is not well-defined. Methods: Thirty-four surgically resected pT1 CRCs were reevaluated for 2-dimensional (2D) VI using hematoxylin and eosin (H&E)–stained slides with additional elastic and desmin immunohistochemical staining (cohort A). Additionally, 27 pT1 CRCs without knowing VI status were selected for 3-dimensional (3D) VI evaluation only (cohort B). All 61 cases (cohorts A and B) were studied in 3D using tissue clearing. Results: VI was detected more commonly in 3D (17/34, 50.0%) than in 2D H&E slide evaluation (9/34, 26.5%, p = .047). When VI was identified in 3D (27/61, 44.3%), the most common phase was that of intraluminal growth (22/27, 81.5%), followed by intravasation (7/27, 25.9%) and extravasation (5/27, 18.5%). E-cadherin expression was characterized in 3D in foci of VI and varied in each phase of invasion. Conclusions: All three phases were observed in VI of pT1 CRCs. The extravasation of neoplastic cells from foci of VI in pT1 CRC suggests that VI could be a route of intratumoral spreading in a subset of pT1 CRCs.
3.Association between Obesity and Melanoma Risk in an Asian Population: A Nationwide Cohort Study
Hye Yeon KOO ; Kyungdo HAN ; Jihye PARK ; Jinhyung JUNG ; Seonghye KIM ; Hyeonjin CHO ; In Young CHO ; Dong Wook SHIN
Cancer Research and Treatment 2026;58(2):677-685
Purpose:
Previous studies from mostly Western populations have suggested possible associations between obesity and melanoma risk. This study aimed to investigate associations between obesity status and melanoma using a nationwide cohort of Koreans.
Materials and Methods:
A total of 4,441,403 adults who received a national health examination in 2012 were included from the Korean National Health Insurance Service database, and followed until December 31, 2022. Obesity status was defined based on the body mass index at the baseline health examination. Cox proportional hazards analyses were performed to evaluate associations between obesity status and incident melanoma, with adjustment for confounders. Stratified analyses were performed by sex and menopausal status (in women).
Results:
Overall, melanoma risk increased according to obesity status (p for trend=0.024); adjusted hazard ratios (95% confidence intervals) for melanoma risk were 0.766 (0.438–1.340) in underweight; 1.292 (1.072–1.557) in overweight; 1.202 (1.002–1.442) in obesity; and 1.191 (0.798–1.778) in severe obesity compared to normal weight (reference). In stratified analyses, similar trends to those of the overall study population were observed among men and premenopausal women (p for trend=0.052 in men and 0.036 in premenopausal women). Among premenopausal women, the risk of melanoma increased linearly with obesity status. Meanwhile, among postmenopausal women, melanoma risk showed no significant difference or trend according to obesity status.
Conclusion
Overweight and obesity were associated with increased risk of melanoma in a population-based cohort of Koreans. Obese individuals, especially men and premenopausal women, may require more thorough prevention and screening strategies for melanoma.
4.Survival Rates of Patients with Gastric Cancer According to Age and Sex: A Large-Scale Study Using Data from 14,739 Patients
Yonghoon CHOI ; Nayoung KIM ; Ji Hyun KIM ; Hyeong Ho JO ; Hyeon Jeong OH ; Hye Seung LEE ; Yu Kyung JUN ; Hyuk YOON ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE ; So Hyun KANG ; Young Suk PARK ; Sang-Hoon AHN ; Yun-Suhk SUH ; Do Joong PARK ; Hyung Ho KIM ; Ji-Won KIM ; Jin Won KIM ; Keun-Wook LEE ; Won CHANG ; Yoon Jin LEE ; Kyoung Ho LEE ; Young Hoon KIM
Cancer Research and Treatment 2026;58(1):252-263
Purpose:
The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex.
Materials and Methods:
Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed.
Results:
Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males.
Conclusion
Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.
5.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part II. Follow-up Surveillance after Initial Treatment 2026
Eun Kyung LEE ; Seung Heon KANG ; Bon Seok KOO ; Mijin KIM ; Min Joo KIM ; Bo Hyun KIM ; Ji Won KIM ; Dong Gyu NA ; Sohyun PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Young-Ik SON ; Young Shin SONG ; Dong Yeob SHIN ; Jong-Hyuk AHN ; Hwa Young AHN ; So Won OH ; Ho-Ryun WON ; Won Sang YOO ; Min Kyoung LEE ; Sang-Woo LEE ; Jeongmin LEE ; Ji Ye LEE ; Dong-Jun LIM ; Ki-Wook CHUNG ; Ari CHONG ; Jin Hyang JUNG ; Sun Wook CHO ; Yoon Young CHO ; Chae Moon HONG ; Young Joo PARK ;
International Journal of Thyroidology 2026;19(1):1-40
In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.
6.Association of body image distortion with smartphone dependency and usage time in adolescents: a cross-sectional Korean Youth Study
Haein CHO ; Junhee PARK ; Dagyeong LEE ; Dong Wook SHIN
Korean Journal of Family Medicine 2025;46(2):98-106
Background:
Adolescent dependency on smartphones is the highest among all age groups. Adolescents can be influenced to evaluate their body image by popular ideals about beautiful bodies via smartphone content, which can cause body image distortion. This study aimed to examine the association between body image distortion and smartphone dependency and the duration of smartphone usage among Korean adolescents.
Methods:
This study used data from the 16th Korean Youth Risk Behavior Web-Based Survey (2020), and included 42,981 participants, who were grouped according to self-reported duration of smartphone usage and smartphone dependency, as measured by a questionnaire. Body image distortion is defined as an exaggerated subjective body image compared to the actual body image. Multivariable-adjusted logistic regression was used to determine the odds ratios (ORs) with 95% confidence intervals (CIs) of body image distortion on smartphone dependency and usage time after adjusting for various factors related to body image distortion.
Results:
Among the 42,981 participants, both moderate and high levels of smartphone dependency were associated with body image distortion in boys (moderate: adjusted OR [aOR], 1.11; 95% CI, 1.01–1.22; high: aOR, 1.18; 95% CI, 1.05–1.32) and girls (moderate: aOR, 1.14; 95% CI, 1.05–1.23; high: aOR, 1.30; 95% CI, 1.18–1.42) compared to the low-level dependency group. However, no significant association was found between smartphone usage duration and body image distortion.
Conclusion
Our study demonstrated that moderate to high levels of smartphone dependency are associated with body image distortion in adolescents. Therefore, it is necessary to establish strategies for checking and managing adolescents’ smartphone dependence.
7.Weight Change after Cancer Diagnosis and Risk of Diabetes Mellitus: A Population-Based Nationwide Study
Hye Yeon KOO ; Kyungdo HAN ; Mi Hee CHO ; Wonyoung JUNG ; Jinhyung JUNG ; In Young CHO ; Dong Wook SHIN
Cancer Research and Treatment 2025;57(2):339-349
Purpose:
Cancer survivors are at increased risk of diabetes mellitus (DM). Additionally, the prevalence of obesity, which is also a risk factor for DM, is increasing in cancer survivors. We investigated the associations between weight change after cancer diagnosis and DM risk.
Materials and Methods:
This retrospective cohort study used data from the Korean National Health Insurance Service. Participants who were newly diagnosed with cancer from 2010 to 2016 and received national health screening before and after diagnosis were included and followed until 2019. Weight change status after cancer diagnosis was categorized into four groups: sustained normal weight, obese to normal weight, normal weight to obese, or sustained obese. Cox proportional hazard analyses were performed to examine associations between weight change and DM.
Results:
The study population comprised 264,250 cancer survivors. DM risk was highest in sustained obese (adjusted hazard ratios [aHR], 2.17; 95% confidence interval [CI], 2.08 to 2.26), followed by normal weight to obese (aHR, 1.66; 95% CI, 1.54 to 1.79), obese to normal weight (aHR, 1.29; 95% CI, 1.21 to 1.39), and then sustained normal weight group (reference). In subgroup analyses according to cancer type, most cancers showed the highest risks in sustained obese group.
Conclusion
Obesity at any time point was related to increased DM risk, presenting the highest risk in cancer survivors with sustained obesity. Survivors who changed from obese to normal weight had lower risk than survivors with sustained obesity. Survivors who changed from normal weight to obese showed increased risk compared to those who sustained normal weight. Our finding supports the significance of weight management among cancer survivors.
8.Incidence of complicated appendicitis before and after the COVID-19 pandemic: a comparative analysis
Haksoo KIM ; Dongkil JEONG ; Young Soon CHO ; Geum Jong SONG ; Hyung Jun MOON ; Tae Yong SHIN ; Dong Wook LEE ; Hyun Joon KIM ; Hyun Jung LEE ; Sun In HONG
Journal of the Korean Society of Emergency Medicine 2025;36(1):12-19
Objective:
It has been 1 year since the start of the worldwide coronavirus disease-19 (COVID-19) pandemic. This study analyzed the indirect effects of COVID-19 on treating patients with non-infectious diseases by comparing the incidence of complicated appendicitis before and after the pandemic.
Methods:
The target group included patients aged at least 16 years diagnosed with acute appendicitis between February 23 and July 31, 2020. Patients diagnosed during the same period in 2019 were selected as the control group. The differences in the incidence of complicated appendicitis before and after COVID-19 were investigated, and the association with various variables was analyzed using the odds ratios and 95% confidence intervals (CIs).
Results:
The study included 120 subjects in 2019 (pre-COVID group) and 119 cases in 2020 (post-COVID group). The pre-COVID group included 25 cases (20.8%) of complicated appendicitis, while the post-COVID group included 48 cases (40.3%). The median time from symptom onset to visit (pre-hospital time) increased from 15 to 22 hours, and the median time from the visit to surgery (in-hospital time) increased from 7 to 11 hours. Multivariate regression analysis of the three variables revealed odds ratios (95% CIs) of pre-hospital time, erythrocyte sedimentation rate, and inclusion in the post-COVID group of 1.02 (1.01-1.02), 2.07 (1.11-3.86), and 2.15 (1.12-4.11), respectively.
Conclusion
The incidence of complicated appendicitis increased after the COVID-19 pandemic. Therefore, a healthcare system that can minimize the delay in treating non-infectious emergency patients is needed.
9.Association of body image distortion with smartphone dependency and usage time in adolescents: a cross-sectional Korean Youth Study
Haein CHO ; Junhee PARK ; Dagyeong LEE ; Dong Wook SHIN
Korean Journal of Family Medicine 2025;46(2):98-106
Background:
Adolescent dependency on smartphones is the highest among all age groups. Adolescents can be influenced to evaluate their body image by popular ideals about beautiful bodies via smartphone content, which can cause body image distortion. This study aimed to examine the association between body image distortion and smartphone dependency and the duration of smartphone usage among Korean adolescents.
Methods:
This study used data from the 16th Korean Youth Risk Behavior Web-Based Survey (2020), and included 42,981 participants, who were grouped according to self-reported duration of smartphone usage and smartphone dependency, as measured by a questionnaire. Body image distortion is defined as an exaggerated subjective body image compared to the actual body image. Multivariable-adjusted logistic regression was used to determine the odds ratios (ORs) with 95% confidence intervals (CIs) of body image distortion on smartphone dependency and usage time after adjusting for various factors related to body image distortion.
Results:
Among the 42,981 participants, both moderate and high levels of smartphone dependency were associated with body image distortion in boys (moderate: adjusted OR [aOR], 1.11; 95% CI, 1.01–1.22; high: aOR, 1.18; 95% CI, 1.05–1.32) and girls (moderate: aOR, 1.14; 95% CI, 1.05–1.23; high: aOR, 1.30; 95% CI, 1.18–1.42) compared to the low-level dependency group. However, no significant association was found between smartphone usage duration and body image distortion.
Conclusion
Our study demonstrated that moderate to high levels of smartphone dependency are associated with body image distortion in adolescents. Therefore, it is necessary to establish strategies for checking and managing adolescents’ smartphone dependence.
10.Association of body image distortion with smartphone dependency and usage time in adolescents: a cross-sectional Korean Youth Study
Haein CHO ; Junhee PARK ; Dagyeong LEE ; Dong Wook SHIN
Korean Journal of Family Medicine 2025;46(2):98-106
Background:
Adolescent dependency on smartphones is the highest among all age groups. Adolescents can be influenced to evaluate their body image by popular ideals about beautiful bodies via smartphone content, which can cause body image distortion. This study aimed to examine the association between body image distortion and smartphone dependency and the duration of smartphone usage among Korean adolescents.
Methods:
This study used data from the 16th Korean Youth Risk Behavior Web-Based Survey (2020), and included 42,981 participants, who were grouped according to self-reported duration of smartphone usage and smartphone dependency, as measured by a questionnaire. Body image distortion is defined as an exaggerated subjective body image compared to the actual body image. Multivariable-adjusted logistic regression was used to determine the odds ratios (ORs) with 95% confidence intervals (CIs) of body image distortion on smartphone dependency and usage time after adjusting for various factors related to body image distortion.
Results:
Among the 42,981 participants, both moderate and high levels of smartphone dependency were associated with body image distortion in boys (moderate: adjusted OR [aOR], 1.11; 95% CI, 1.01–1.22; high: aOR, 1.18; 95% CI, 1.05–1.32) and girls (moderate: aOR, 1.14; 95% CI, 1.05–1.23; high: aOR, 1.30; 95% CI, 1.18–1.42) compared to the low-level dependency group. However, no significant association was found between smartphone usage duration and body image distortion.
Conclusion
Our study demonstrated that moderate to high levels of smartphone dependency are associated with body image distortion in adolescents. Therefore, it is necessary to establish strategies for checking and managing adolescents’ smartphone dependence.

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