1.Comorbidity network of post-traumatic stress and depressive symptoms during the COVID-19 pandemic in Korea
Yujin LEE ; Ji Su YANG ; Alexander C. TSAI ; Jee In KANG ; Hearan KOO ; Hyeon Woo YIM ; Hyeon Chang KIM ; Sun Jae JUNG
Epidemiology and Health 2026;48(1):e2026006-
OBJECTIVES:
The coronavirus disease 2019 (COVID-19) pandemic had direct effects on population health through infection and morbidity, as well as indirect effects on population mental health. We estimated the network structure of post-traumatic stress symptoms (PTSS) and depressive symptoms throughout the pandemic in Korea and aimed to identify the most central and bridging symptoms.
METHODS:
Participants aged 30–64 years completed mental health surveys across 3 phases of the COVID-19 pandemic: March 2020 (n=1,925), February–March 2021 (n=1,754), and December 2021–January 2022 (n=1,595). Using PTSS and depressive symptom data, we conducted network analyses, and the primary measures of symptom importance (centrality) were expected influence and bridge expected influence.
RESULTS:
In the comorbidity network, although the most central symptoms fluctuated over the course of the pandemic, sleep problems were consistently identified as the most influential bridge symptoms throughout. The symptom network structure differed between the subacute and chronic phases of the pandemic.
CONCLUSIONS
We found evidence of changes in the network structure of PTSS and depressive symptoms, even as sleep problems retained a consistent role as a bridging symptom. Although overall network structures varied across phases of the pandemic, the bridging role of sleep-related symptoms remained consistently strong, suggesting that sleep problems may represent a general and enduring mechanism underlying PTSS–depression comorbidity. During future pandemics, prompt screening for sleep problems may help prevent the development of comorbidity between PTSS and depressive symptoms.
2.Evaluation of Silicone-Based Gel for the Treatment of Hypertrophic Scarring in Rat Models
So-Jeong YIM ; Da-Ye NAM ; Da-Hye CHOI ; Jin WOO ; Youngtae KIM ; JungHoon CHAE ; Young-Shin LEE ; Ji-Youl JUNG
Journal of Wound Management and Research 2024;20(2):122-127
Background:
Hypertrophic scarring represents an aberrant response to wounds in certain individuals, manifesting with symptoms such as itching, tenderness, pain, and pigmentation. This study aimed to investigate the impact of a silicone-based gel on the healing of hypertrophic scars, particularly those originating from deep tissue wounds.
Methods:
A rat model of wound healing and scarring was established, and 12 rats were randomly assigned to three groups: Dermatix Ultra group, SFG-100 silicone-gel group, and non-treated group. Rats in the treated groups (Dermatix Ultra and SFG-100 silicone-gel) received twice-daily applications for 8 weeks. Histologic analysis, including biopsy, was conducted to evaluate the scar elevation index, epidermis thickness, and the number of granulation veins.
Results:
Overall, both the Dermatix Ultra and SFG-100 silicone-gel groups exhibited improvements in hypertrophic scar healing, accompanied by a significant reduction in skin pigmentation. Histopathologically, scars in both treated groups displayed a notable decrease in scar elevation index, epithelial thickness, and collagen disorganization compared to the non-treated group. However, no significant difference was observed between the Dermatix Ultra and SFG-100 silicone-gel groups.
Conclusion
The results suggest that SFG-100 silicone-gel is an effective therapeutic agent for hypertrophic scars. Further research is warranted to elucidate the mechanisms underlying its efficacy and to optimize its application for clinical use.
3.Impact of the COVID-19 Pandemic on Gender Differences in Depression Based on National Representative Data
Hyunsuk JEONG ; Hyeon Woo YIM ; Seung-Yup LEE ; Da Young JUNG
Journal of Korean Medical Science 2023;38(6):e36-
Background:
Restrictions on daily life and changes in economic structure due to coronavirus disease 2019 (COVID-19) likely would have affected men and women differently. However, there is still a lack of research on the difference between men and women in the amount of change in depression during COVID-19 compared to before COVID-19. Therefore, the researchers investigated gender differences in the magnitude of increase in the prevalence of depression with its severity and individual symptoms during COVID-19 compared with prepandemic levels.
Methods:
The Korea National Health and Nutrition Examination Survey (KNHANES) 2016 and 2018 were used to assess depression levels pre-pandemic and the KNHANES 2020 for pandemic depression levels. Depression was evaluated using the Patient Health Questionnaire-9 (PHQ-9). To analyze the differences between men and women in the magnitude of the mental health impact of COVID-19, the researchers analyzed the weighted differences in depression prevalence, severity, and individual symptoms during the COVID-19 pandemic compared to before COVID-19 stratified by gender.
Results:
In men, there were significant increases in weighted prevalence for depression (1.2% percentage point; 95% confidence interval [CI], 0.0–2.3) and severe symptoms of depression (2.6-fold; 95% CI, 1.2–5.7). Among the individual symptoms of depression, significant increases during the pandemic compared to before were: little interest or pleasure in doing things, 1.26-fold; feeling tired or having little energy, 2.2-fold; and suicidal thoughts, 1.7-fold. However, there was no significant difference in prevalence, symptoms severity, and any symptom before and during COVID-19 in women.
Conclusions
Because the pandemic is likely to increase mental problems of the affected over time due to such problems as financial stress and joblessness or post-infection health issues, the researchers anticipate an increase in the prevalence of some mental illnesses. In particular, since the suicide rate of men is higher than that of women, from a public health perspective, active interventions are needed to prevent an increase in the suicide rate due to COVID-19. It is also necessary to establish national policies to overcome the psychological, social, and economic losses resulting from COVID-19.
4.Long-Term Risk of Cardiovascular Disease Among Type 2 Diabetes Patients According to Average and Visit-to-Visit Variations of HbA1c Levels During the First 3 Years of Diabetes Diagnosis
Hyunah KIM ; Da Young JUNG ; Seung-Hwan LEE ; Jae-Hyoung CHO ; Hyeon Woo YIM ; Hun-Sung KIM
Journal of Korean Medical Science 2023;38(4):e24-
Background:
It remains unclear whether a combination of glycemic variability and glycated hemoglobin (HbA1c) status leads to a higher incidence of cardiovascular disease (CVD).Therefore, to investigate CVD risk according to the glucose control status during early diabetes, we examined visit-to-visit HbA1c variability among patients with type 2 diabetes (T2DM).
Methods:
In this 9-year retrospective study, we measured HbA1c levels at each visit and tracked the change in HbA1c levels for 3 years after the first presentation (observation window) in newly diagnosed T2DM patients. We later assessed the occurrence of CVD in the last 3 years (target outcome window) of the study period after allowing a 3-year buffering window. The HbA1c variability score (HVS; divided into quartiles, HVS_Q1–4) was used to determine visit-to-visit HbA1c variability.
Results:
Among 4,817 enrolled T2DM patients, the mean HbA1c level was < 7% for the first 3 years. The group with the lowest HVS had the lowest rate of CVD (9.4%; 104/1,109 patients).The highest incidence of CVD of 26.7% (8/30 patients) was found in HVS [≥ 9.0%]_Q3, which was significantly higher than that in HVS [6.0–6.9%]_Q1 (P = 0.006), HVS [6.0–6.9%]_Q2 (P = 0.013), HVS [6.0–6.9%]_Q3 (P = 0.018), and HVS [7.0–7.9%]_Q3 (P = 0.040).
Conclusion
To our knowledge, this is the first long-term study to analyze the importance of both HbA1c change and visit-to-visit HbA1c variability during outpatient visits within the first 3 years. Lowering glucose levels during early diabetes may be more critical than reducing visit-to-visit HbA1c variability.
5.Digital Breast Tomosynthesis Plus Ultrasound Versus Digital Mammography Plus Ultrasound for Screening Breast Cancer in Women With Dense Breasts
Su Min HA ; Ann YI ; Dahae YIM ; Myoung-jin JANG ; Bo Ra KWON ; Sung Ui SHIN ; Eun Jae LEE ; Soo Hyun LEE ; Woo Kyung MOON ; Jung Min CHANG
Korean Journal of Radiology 2023;24(4):274-283
Objective:
To compare the outcomes of digital breast tomosynthesis (DBT) screening combined with ultrasound (US) with those of digital mammography (DM) combined with US in women with dense breasts.
Materials and Methods:
A retrospective database search identified consecutive asymptomatic women with dense breasts who underwent breast cancer screening with DBT or DM and whole-breast US simultaneously between June 2016 and July 2019. Women who underwent DBT + US (DBT cohort) and DM + US (DM cohort) were matched using 1:2 ratio according to mammographic density, age, menopausal status, hormone replacement therapy, and a family history of breast cancer. The cancer detection rate (CDR) per 1000 screening examinations, abnormal interpretation rate (AIR), sensitivity, and specificity were compared.
Results:
A total of 863 women in the DBT cohort were matched with 1726 women in the DM cohort (median age, 53 years; interquartile range, 40–78 years) and 26 breast cancers (9 in the DBT cohort and 17 in the DM cohort) were identified. The DBT and DM cohorts showed comparable CDR (10.4 [9 of 863; 95% confidence interval {CI}: 4.8–19.7] vs. 9.8 [17 of 1726;95% CI: 5.7–15.7] per 1000 examinations, respectively; P = 0.889). DBT cohort showed a higher AIR than the DM cohort (31.6% [273 of 863; 95% CI: 28.5%–34.9%] vs. 22.4% [387 of 1726; 95% CI: 20.5%–24.5%]; P < 0.001). The sensitivity for both cohorts was 100%. In women with negative findings on DBT or DM, supplemental US yielded similar CDRs in both DBT and DM cohorts (4.0 vs. 3.3 per 1000 examinations, respectively; P = 0.803) and higher AIR in the DBT cohort (24.8% [188 of 758; 95% CI: 21.8%–28.0%] vs. 16.9% [257 of 1516; 95% CI: 15.1%–18.9%; P < 0.001).
Conclusion
DBT screening combined with US showed comparable CDR but lower specificity than DM screening combined with US in women with dense breasts.
6.The Change of Suicidal Ideation Over a 12-Week Naturalistic Treatment of Depression: Comparison Between Young People and Older Adults
Young-Eun JUNG ; Tae-Youn JUN ; Young Sup WOO ; Hyeon Woo YIM ; Jung-Bum KIM ; Jae-Min KIM ; Ho-Jun SEO
Psychiatry Investigation 2023;20(1):9-17
Objective:
We investigated the differences in suicidality between young people and older adults with depression over the course of 12-week naturalistic treatment with antidepressants.
Methods:
A total of 565 patients who had moderate to severe depression (Hamilton Depression Rating Scale [HAM-D] score ≥14) and significant suicidal ideation (Beck Scale for Suicide Ideation [SSI-B] score ≥6) were recruited from 18 hospitals. Participants were classified into two groups: the younger group (13–24 years of age, n=82) and the older group (≥25 years of age, n=483). Total scores over time on the SSI-B, HAM-D, and Hamilton Anxiety Rating Scale (HAM-A) were assessed and compared between the two groups.
Results:
At baseline, the younger group had lower HAM-D scores (21.0 vs. 22.2; p=0.028) but higher SSI-B scores (19.4 vs. 15.6; p<0.001) compared with the older group. The overall 12-week proportion of patients with resolved suicidality was 44.1% in the younger group and 69.2% in the older group. Although the improvement in the HAM-D and HAM-A scores did not differ between the groups, suicidal ideation in the younger group remained more severe than in the older group throughout the treatment. The ratio of the subjects who achieved HAM-D remission or response but did not achieve SSI-B remission was significantly higher in the younger group than in the older group.
Conclusion
These data suggest that in depressed youths, suicide risk is a serious concern throughout the course of depression even when favorable treatment outcomes are obtained.
7.Korea Seroprevalence Study of Monitoring of SARS-COV-2 Antibody Retention and Transmission (K-SEROSMART): findings from national representative sample
Jina HAN ; Hye Jin BAEK ; Eunbi NOH ; Kyuhyun YOON ; Jung Ae KIM ; Sukhyun RYU ; Kay O LEE ; No Yai PARK ; Eunok JUNG ; Sangil KIM ; Hyukmin LEE ; Yoo-Sung HWANG ; Jaehun JUNG ; Hun Jae LEE ; Sung-il CHO ; Sangcheol OH ; Migyeong KIM ; Chang-Mo OH ; Byengchul YU ; Young-Seoub HONG ; Keonyeop KIM ; Sunjae JUNG ; Mi Ah HAN ; Moo-Sik LEE ; Jung-Jeung LEE ; Young HWANGBO ; Hyeon Woo YIM ; Yu-Mi KIM ; Joongyub LEE ; Weon-Young LEE ; Jae-Hyun PARK ; Sungsoo OH ; Heui Sug JO ; Hyeongsu KIM ; Gilwon KANG ; Hae-Sung NAM ; Ju-Hyung LEE ; Gyung-Jae OH ; Min-Ho SHIN ; Soyeon RYU ; Tae-Yoon HWANG ; Soon-Woo PARK ; Sang Kyu KIM ; Roma SEOL ; Ki-Soo PARK ; Su Young KIM ; Jun-wook KWON ; Sung Soon KIM ; Byoungguk KIM ; June-Woo LEE ; Eun Young JANG ; Ah-Ra KIM ; Jeonghyun NAM ; ; Soon Young LEE ; Dong-Hyun KIM
Epidemiology and Health 2023;45(1):e2023075-
OBJECTIVES:
We estimated the population prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including unreported infections, through a Korea Seroprevalence Study of Monitoring of SARS-CoV-2 Antibody Retention and Transmission (K-SEROSMART) in 258 communities throughout Korea.
METHODS:
In August 2022, a survey was conducted among 10,000 household members aged 5 years and older, in households selected through two stage probability random sampling. During face-to-face household interviews, participants self-reported their health status, COVID-19 diagnosis and vaccination history, and general characteristics. Subsequently, participants visited a community health center or medical clinic for blood sampling. Blood samples were analyzed for the presence of antibodies to spike proteins (anti-S) and antibodies to nucleocapsid proteins (anti-N) SARS-CoV-2 proteins using an electrochemiluminescence immunoassay. To estimate the population prevalence, the PROC SURVEYMEANS statistical procedure was employed, with weighting to reflect demographic data from July 2022.
RESULTS:
In total, 9,945 individuals from 5,041 households were surveyed across 258 communities, representing all basic local governments in Korea. The overall population-adjusted prevalence rates of anti-S and anti-N were 97.6% and 57.1%, respectively. Since the Korea Disease Control and Prevention Agency has reported a cumulative incidence of confirmed cases of 37.8% through July 31, 2022, the proportion of unreported infections among all COVID-19 infection was suggested to be 33.9%.
CONCLUSIONS
The K-SEROSMART represents the first nationwide, community-based seroepidemiologic survey of COVID-19, confirming that most individuals possess antibodies to SARS-CoV-2 and that a significant number of unreported cases existed. Furthermore, this study lays the foundation for a surveillance system to continuously monitor transmission at the community level and the response to COVID-19.
8.Long-Term Changes in HbA1c According to Blood Glucose Control Status During the First 3 Months After Visiting a Tertiary University Hospital
Hyunah KIM ; Da Young JUNG ; Seung-Hwan LEE ; Jae-Hyoung CHO ; Hyeon Woo YIM ; Hun-Sung KIM
Journal of Korean Medical Science 2022;37(38):e281-
Background:
We evaluated patients visiting a tertiary university hospital due to a diagnosis of diabetes with a goal of achieving blood glucose control and evaluated blood glucose persistence over 7 years according to the change in blood glucose evident at 3 months after the first visit.
Methods:
Patients treated from 2009 to 2013 were categorized into four groups according to the change in HbA1c levels during the first 3 months of follow-up (Best_group, ≥ 1.6% decrease; Better_group, 0.5–1.5% decrease; Neutral_group, maintained at −0.4% to +0.4%; Worse_group, ≥ 0.5% increase). Each patient’s blood glucose control status was then monitored for 7 years. The incidence of stroke and acute coronary syndrome during this period was confirmed.
Results:
Overall, 9,776 patients were included. HbA1c values were lower in the Best_group than in the other groups at all time points (all P < 0.001). The rate of reaching targets of < 6.5% or < 7.0% HbA1c decreased over time; the rate at which the estimated glomerular filtration rate decreased to < 30 or < 60 mL/min/1.73m 2 increased over time (all trends, P < 0.01).
Conclusion
Blood glucose control status in the first 3 months after initiating hospital care enabled estimation of the patient’s glycemic control status for the next 7 years. In cases with poor initial blood glucose control, a new or more active method of blood glucose control should be sought.
9.Accuracy of one-step automated orthodontic diagnosis model using a convolutional neural network and lateral cephalogram images with different qualities obtained from nationwide multi-hospitals
Sunjin YIM ; Sungchul KIM ; Inhwan KIM ; Jae-Woo PARK ; Jin-Hyoung CHO ; Mihee HONG ; Kyung-Hwa KANG ; Minji KIM ; Su-Jung KIM ; Yoon-Ji KIM ; Young Ho KIM ; Sung-Hoon LIM ; Sang Jin SUNG ; Namkug KIM ; Seung-Hak BAEK
The Korean Journal of Orthodontics 2022;52(1):3-19
Objective:
The purpose of this study was to investigate the accuracy of one-step automated orthodontic diagnosis of skeletodental discrepancies using a convolutional neural network (CNN) and lateral cephalogram images with different qualities from nationwide multi-hospitals.
Methods:
Among 2,174 lateral cephalograms, 1,993 cephalograms from two hospitals were used for training and internal test sets and 181 cephalograms from eight other hospitals were used for an external test set. They were divided into three classification groups according to anteroposterior skeletal discrepancies (Class I, II, and III), vertical skeletal discrepancies (normodivergent, hypodivergent, and hyperdivergent patterns), and vertical dental discrepancies (normal overbite, deep bite, and open bite) as a gold standard. Pre-trained DenseNet-169 was used as a CNN classifier model. Diagnostic performance was evaluated by receiver operating characteristic (ROC) analysis, t-stochastic neighbor embedding (t-SNE), and gradientweighted class activation mapping (Grad-CAM).
Results:
In the ROC analysis, the mean area under the curve and the mean accuracy of all classifications were high with both internal and external test sets (all, > 0.89 and > 0.80). In the t-SNE analysis, our model succeeded in creating good separation between three classification groups. Grad-CAM figures showed differences in the location and size of the focus areas between three classification groups in each diagnosis.
Conclusions
Since the accuracy of our model was validated with both internal and external test sets, it shows the possible usefulness of a one-step automated orthodontic diagnosis tool using a CNN model. However, it still needs technical improvement in terms of classifying vertical dental discrepancies.
10.Network Analysis of the Symptoms of Depressive Disorders Over the Course of Therapy: Changes in Centrality Measures
Seon-Cheol PARK ; Yaeseul KIM ; Kiwon KIM ; Young Sup WOO ; Jung-Bum KIM ; Eun Young JANG ; Hwa-Young LEE ; Hyeon-Woo YIM ; Byung-Joo HAM ; Jae-Min KIM ; Yong Chon PARK
Psychiatry Investigation 2021;18(1):48-58
Objective:
Network analysis can be used in terms of a novel psychopathological approach for depressive syndrome. We aimed to estimate the successive network structures of depressive symptoms in patients with depressive disorder using data from the Clinical Research Center for Depression study.
Methods:
We enrolled 1,152 South Korean adult patients with depressive disorders who were beginning treatment for first-onset or recurrent depressive episodes. We examined the network structure of the severities of the items on the Hamilton Depression Rating Scale (HAMD) at baseline and at weeks 2, 12, 25, and 52. The node strength centrality of all the HAMD items at baseline and at week 2, 12, 25, and 52 in terms of network analysis.
Results:
In the severity networks, the anxiety (psychic) item was the most centrally situated in the initial period (baseline and week 2), while loss of weight was the most centrally situated item in the later period (weeks 25 and 52). In addition, the number of strong edges (i.e., edges representing strong correlations) increased in the late period compared to the initial period.
Conclusion
Our findings support a period-specific and symptom-focused therapeutic approach that can provide complementary information to the unidimensional total HAMD score.

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