Background: This study aimed to examine trends in the prevalence, incidence, metabolic characteristics, and management of type 2 diabetes mellitus (T2DM) among young adults in South Korea. Methods: Young adults with T2DM were defined as individuals aged 19 to 39 years who met the diagnostic criteria for T2DM. Data from the Korean National Health Insurance Service-Customized Database (2010–2020, n=225,497–372,726) were analyzed to evaluate trends in T2DM prevalence, incidence, metabolic profiles, comorbidities, and antidiabetic drug prescription. Additional analyses were performed using the Korea National Health and Nutrition Examination Survey. Results: The prevalence of T2DM in young adults significantly increased from 1.02% in 2010 to 2.02% in 2020 (P<0.001), corresponding to 372,726 patients in 2020. Over the same period, the incidence rate remained stable within the range of 0.36% to 0.45%. Prediabetes prevalence steadily increased from 15.53% to 20.92%, affecting 3.87 million individuals in 2020. The proportion of young adults with T2DM who were obese also increased, with 67.8% having a body mass index (BMI) ≥25 kg/m² and 31.6% having a BMI ≥30 kg/m² in 2020. The prevalence of hypertension, dyslipidemia, and fatty liver disease also increased, reaching 34.2%, 79.8%, and 78.9%, respectively, in 2020. Although the overall pharmacological treatment rate remained low, the prescription of antidiabetic medications with weight-reducing properties increased over the study period. Conclusion The prevalence of T2DM among young adults in South Korea nearly doubled over the past decade. The strong association with obesity and metabolic comorbidities emphasizes the urgent need for targeted prevention and management strategies tailored to this population.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background and Objectives: Certain medications are associated with ototoxicity. This study assesses drug-induced ototoxicity in South Korea by analyzing the Korean national health data. Subjects and Methods: Hospital records of National Health Insurance members from 2009 to 2016 were reviewed. Data were compared between patients with and without hearing loss (HL). Individuals with HL were identified as having a primary diagnosis code for sensorineural HL or another type of HL in at least one outpatient or inpatient record according to the International Classification of Diseases-10. Results: The members in the HL group increased slightly from 0.8% to 1.0% relative to the total sample, compared with 99.2% to 99.0% among the controls. The proportion of males in the HL group ranged from 45.6% to 47.6%, compared with 48.4% to 48.8% among the controls. The proportion of those aged ≥65 years in the HL group increased from 34.1% to 41.4%, compared with 10.6% to 13.3% among the controls. Hypertension prevalence (24.7%-25.7%) in the HL group was higher than that in the control group (12%-12.6%). Diabetes prevalence in the HL group was 10.6%-12.3%, compared with 4.4%-5.9% among the controls. The use of proton pump inhibitor components increased, particularly esomeprazole magnesium trihydrate and rabeprazole sodium, whereas the usage of pantoprazole sodium sesquihydrate and revaprazan was high initially but declined subsequently. The usage of painkillers such as acetaminophen, loxoprofen sodium, and ibuprofen remained high, and antibiotics such as cephalosporins indicated the highest usage. However, the use of penicillin antibiotics such as amoxicillin decreased significantly. Anticancer agents showed relatively low usage compared with other drug categories, whereas antihistamines showed extremely high usage across all years, with a continual increase. Conclusions These correlations and the underlying mechanisms necessitate further investigation, as several medicines have been linked to an increased risk of HL.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: The novel curability criteria for elderly (EL) patients have been proposed to stratify their risk of lymph node metastasis (LNM), following non-curative endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Hence, this study aimed to evaluate the effectiveness of the EL criteria and compare them with those of the well-known eCura system. Materials and Methods: A retrospective analysis was performed on 143 patients who did not meet the curative ESD criteria at a tertiary hospital in Korea between 2011 and 2022. Of these, 102 underwent additional surgery, while 41 were followed up without further treatment. The LNM rates based on the EL and eCura systems were stratified and compared. Results: In the surgery group, 29.4% (30/102) patients were classified as EL-low (EL-L) and 70.2% (72/102) as EL-high (EL-H). The LNM rates (95% confidence interval) were 0.0% (0.0–11.6) and 9.7% (4.0–19.0) for EL-L and EL-H, respectively (P=0.102). EL-L was closely aligned with the eCura low-risk category, with a similar patient proportion (32.4%) and an LNM rate of 0.0% (0.0–10.6). The eCura system classified 94.1% (48/51) of the EL-L patients as lowrisk, with an 86% concordance rate (123/143). Discordant cases included patients with positive vertical margins, but without other risk factors, who were classified as EL-H without LNM. Conclusions Patients with EL-L showed no LNM, and the EL criteria demonstrated high concordance with the eCura system. The EL criteria may be as effective as the eCura system in identifying low-risk patients after non-curative ESD for EGC.

Background: To assess the quality of life (QoL) and treatment satisfaction with intermittently-scanned continuous glucose monitoring (isCGM) in women with gestational diabetes mellitus (GDM). Methods: This prospective observational study included 189 women with GDM who completed the Korean version of the Audit of Diabetes-Dependent Quality of Life Questionnaire (K-ADDQoL). Among them, 25 women who utilized isCGM between gestational weeks 30 and 34 completed the Korean version of the Diabetes Treatment Satisfaction Questionnaire change version (K-DTSQc) to evaluate their satisfaction with isCGM during pregnancy. Results: GDM had a negative impact on the perceived QoL in 89.4% of the women. All 19 domains of the K-ADDQoL were adversely influenced by GDM, with the most significant impact on the freedom to eat (weighted impact score, −6.98 ± 2.49, P < 0.001) and the least impact on the sex life (−0.25 ± 0.80, P = 0.008). Younger women and those treated with insulin perceived themselves as being more affected in their QoL due to GDM. Women perceived to have less effect on their QoL attributed to GDM exhibited higher ΔHbA1c one year after delivery (ΔHbA1c, 0.3 ± 0.4% vs. 0.0 ± 0.4% in less affected vs. more affected women). The utilization of isCGM improved treatment satisfaction (overall satisfaction score, 10.36 ± 9.21, P < 0.001), independent of glycemic control during pregnancy. Conclusion Although GDM negatively affects the perceived QoL during pregnancy, attentiveness to GDM management may have a positive impact on long-term glycemic control.Moreover, employing isCGM can enhance treatment satisfaction in women with GDM.

South Korea’s current vaccination policies leave a surveillance gap for non-National Immunization Program (NIP) vaccines. In this study, we proposed a sentinel surveillance approach for monitoring the safety of non-NIP vaccines. Vaccination data were collected retrospectively among patients hospitalized with pre-defined adverse events of special interest (AESI) by reviewing electronic medical records in five university hospitals. This approach incorporates expert assessment to determine the causal relationship. We confirmed that 16 patients had received non-NIP vaccines among 860 patients diagnosed with AESI.We concluded one case of preeclampsia was possibly related to tetanus-diphtheria-pertussis vaccination. We propose a multi-hospital-based, retrospective assessment system for predefined AESIs as an alternative to active vaccine safety monitoring method. These efforts are expected to enhance both the accuracy and timeliness of safety monitoring in South Korea.

Background: Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context. Methods: A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7–9) and ≤ 15% disagreement (score of 1–3). Statistical measures such as content validity ratio and Kendall’s coefficient of concordance (W) were calculated to assess agreement levels. Results: Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall’s W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall’s W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities. Conclusion This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.

Background: Tinnitus is a bothersome condition associated with various mechanisms of action. Although treatment methods vary according to these mechanisms, standardized guidelines would benefit both patients and clinicians. We conducted a Delphi study, a method that collects expert opinions through multiple rounds of questionnaires, to reach a consensus on tinnitus treatment with professional experts. Methods: A two-round modified Delphi survey was conducted to develop a clinical consensus on tinnitus treatment. The experts scored each statement on a scale of 1 (highest disagreement) to 9 (highest agreement) for their level of agreement on tinnitus treatment.Consensus was defined when 75% or more of the participants scored 7–9, and 15% or less scored 1–3. To ensure reliability of the responses, the content validity ratio and Kendall’s coefficient of concordance were evaluated. Results: Approximately 19 of 31 statements reached a consensus. All 3 statements reached a consensus regarding the candidates for treatment. Regarding treatment, 3 of 8 statements on medication, 2 of 2 statements on tinnitus retraining therapy/cognitive behavioral therapy, and 5 of 7 statements on auditory rehabilitation reached a positive consensus. Although all 6 statements regarding miscellaneous treatment reached a consensus, most were negatively agreed. For treatment with neuromodulation, none of the 5 statements reached a consensus. Conclusion The experts reached a high level of consensus on treatment candidates, tinnitus retraining therapy/cognitive behavioral therapy, and auditory rehabilitation in this modified Delphi study. The results of this study can provide beneficial and practical information for clinicians regarding the treatment of tinnitus.