The impact of the expanded health insurance coverage policy on healthcare spending: evidence from Korea.

BACKGROUND: South Korea's National Health Insurance (NHI) system pursues universal health coverage, but it has not been able to alleviate patients' financial burden owing to limited coverage and a high proportion of out-of-pocket expenses. In 2017, the government announced a plan to strengthen universality by providing coverage for all unincluded services, expanding coverage, and alleviating household financial burden. We aimed to evaluate the effect of "Moon Care" with a focus on changes in health expenditures following policy implementation, and to provide empirical evidence for future policies to strengthen the NHI system's universality. METHODS: Using data from the 2016 and 2018 Korea Health Panel (KHP), we established a treatment group affected by the policy and an unaffected control group; we ensured homogeneity between the groups using propensity score matching (PSM). Subsequently, we examined changes in NHI payments, non-payments, and out-of-pocket payments (OOP); we performed difference-in-differences (DID) analysis to evaluate the policy's effect. RESULTS: Following policy implementation, the control group had a higher increase than the treatment group in all categories of health expenditures, including NHI payments, non-payments, and OOP. We noted significant decreases in all three categories of health expenditures when comparing the differences before and after policy implementation, as well as between the treatment and control groups. However, we witnessed a significant decrease in the interaction term, which confirms the policy's effect, but only for non-payments. CONCLUSIONS: We observed the policy's intervention effect over time as a decrease in non-payments, on the effectivity of remunerating covered medical services. However, the policy did not work for NHI payments and OOP, suggesting that it failed to control the creation of new non-covered services as noncovered services were converted into covered ones. Thus, it is crucial to discuss the financial spending of health insurance regarding the inclusion of non-covered services in the NHI benefits package.

Medical expenses and its determinants in female patients with urological disorder.

BACKGROUND: The rising older adult population has led to an increase in the prevalence of chronic diseases and medical expenses. Women tend to have a longer healthy life expectancy than men and are more likely to be exposed to urological disorders around the age of 50, resulting in substantial healthcare expenses throughout their lifetime. Urological disorders often require continuous treatment owing to their high risk of recurrence, contributing to an increased financial burden from medical costs. This study aimed to identify factors influencing medical expense in female patients with urological disorders and propose strategies to alleviate the associated financial burden. METHODS: We used data from the Korea Health Panel Survey conducted from 2011 to 2016. The final sample comprised 2,932 patients who visited hospitals for urological disorders. To identify the factors influencing medical expense among female patients with urological disorders, we employed a generalized estimating equation model. RESULTS: The results indicated that younger people and patients with middle-income levels tended to incur higher medical expenses. Furthermore, patients receiving treatment at tertiary hospitals and those enrolled in National Health Insurance also incurred higher health expenses. CONCLUSIONS: This study suggests that effective management of medical expenses related to urological disorders in women requires improvements in healthcare accessibility to facilitate early detection and continuous disease management. In addition, the findings highlight the potential benefits of digital health and non-face-to-face treatments in addressing these needs.

Combining 2'-fucosyllactose and galactooligosaccharides exerts anti-inflammatory effects and promotes gut health.

This study investigated the potential of 2'-Fucosyllactose (2'-FL) and galactooligosaccharides (GOS) combinations as a novel and cost-effective substitute for human milk oligosaccharides (HMOs) in promoting gut health and reducing inflammation. In vitro studies using Caco-2 cells showed that 2'-FL and GOS combinations (H1: GOS:2'-FL ratio of 1.8:1; H2: ratio of 3.6:1) reduced lipopolysaccharide-induced inflammation by decreasing pro-inflammatory markers, while individual treatments had no significant effects. In a mouse model of dextran sulfate sodium (DSS)-induced colitis, combined 2'-FL and GOS supplementation alleviated symptoms, improved gut permeability, and enhanced intestinal structure, with the GH1 group (H1 combo with DSS) being the most effective. 2'-FL and GOS combinations also enhanced short-chain fatty acid production in infant fecal batch fermentation and mouse fecal analysis, with GH1 showing the most promising results. GH1 supplementation altered gut microbiota in mice with DSS-induced colitis, promoting microbial diversity and a more balanced Firmicutes to Bacteroidota ratio. Infant formula products (IFPs) containing 2'-FL and GOS combinations (IFP2: 174 mg GOS and 95 mg 2'-FL per 14 g serving, 1.8:1 ratio; IFP3: 174 mg GOS and 48 mg 2'-FL per 14 g serving, 3.6:1 ratio) demonstrated gastrointestinal protective and anti-inflammatory properties in a coculture model of Caco-2 and THP-1 cells. These findings suggest that 2'-FL and GOS combinations have potential applications in advanced infant formulas and supplements to promote gut health and reduce inflammation.

Risk of cardiovascular events according to the tricyclic antidepressant dosage in patients with chronic pain: a retrospective cohort study.

PURPOSE: We aimed to examine the risk of cardiovascular adverse events by tricyclic antidepressant (TCA) dosage among patients with chronic pain. METHODS: A retrospective cohort study was conducted using a nationwide sample cohort. Among patients aged ≥ 18 years with a chronic pain diagnosis and no history of cardiovascular events, we extracted users and non-users of TCAs through 1:1 propensity score matching. TCA users were categorized into three groups according to the mean defined daily dose (DDD): very low doses (< 0.15 DDD), low doses (0.15-0.34 DDD), and traditional doses (≥ 0.34 DDD). A 6-month follow-up was conducted with an intention-to-treat approach. We examined the hazard ratio of cardiovascular adverse events using Cox proportional hazards analysis. RESULTS: In total, 16,660 matched patients were followed up (8330 TCA users and 8330 non-users). TCA use did not significantly increase cardiovascular adverse events (hazard ratio [HR] 1.12, 95% confidence interval [CI] 0.94-1.33). Low-dose (0.15-0.34 DDD) TCAs (HR 1.37, 95% CI 1.08-1.74), particularly low-dose (0.15-0.34 DDD) nortriptyline (HR 2.11, 95% CI 1.44-3.08), was associated with an increased risk of cardiovascular adverse events. Administration of TCAs at the traditional dose (≥ 0.34 DDD) increased the risk of ischemic stroke (HR 2.08, 95% CI 1.11-3.88). CONCLUSION: Close monitoring of patients on long-term, low-dose use of TCAs should be conducted to avoid an increase in the cumulative dose, which increases the risk of cardiovascular adverse events.

Hutchinson Sign: Biopsy May Assist in Diagnosis of Subungual Melanoma in Situ.

BACKGROUND: Early and accurate diagnosis of subungual melanoma (SUM) through histopathologic examination is critical, but lack of clinical suspicion leads to delays in diagnosis. Hutchinson sign (HS) can be one of the important clinical indicators for diagnosing SUM. OBJECTIVE: To evaluate the diagnostic value of small biopsies of HS for detecting SUM in situ. METHODS: We retrospectively evaluated 12 patients who were diagnosed as SUM in situ and underwent punch biopsy at HS areas. Clinical features, dermoscopic findings, and histopathologic findings in HS regions were analyzed. RESULTS: In most cases, HS was seen in hyponychium (11/12, 91.7%) with 1 case found in proximal nail fold, and 1 case in both the hyponychium and proximal nail fold. Dermoscopic features of HS showed irregular diffuse pigmentation (12/12, 100%) and parallel ridge pattern (7/12, 58.3%). Histopathologically, all cases showed irregularly scattered atypical melanocytes with hyperchromatic nuclei. Two cases showed subtle changes in melanocytes with little nuclear atypia, but additional section specimen showed more definitive findings of SUM in situ. CONCLUSION: We present a supplementary biopsy technique for diagnosing SUM. Biopsy of HS may help in the diagnosis of SUM.

Digital Health Care Industry Ecosystem: Network Analysis.

BACKGROUND: As the need for digital health care based on mobile devices is increasing, with the rapid development of digital technologies, especially in the face of the COVID-19 pandemic, gaining a better understanding of the industrial structure is needed to activate the use of digital health care. OBJECTIVE: The aim of this study was to suggest measures to revitalize the digital health care industry by deriving the stakeholders and major issues with respect to the ecosystem of the industry. METHODS: A total of 1822 newspaper articles were collected using Big Kings, a big data system for news, for a limited period from 2016 to August 2021, when the mobile health care project was promoted in Korea centered on public health centers. The R and NetMiner programs were used for network analysis. RESULTS: The Korean government and the Ministry of Health and Welfare showed the highest centrality and appeared as major stakeholders, and their common major issues were "reviewing the introduction of telemedicine," "concerns about bankruptcy of local clinics," and "building an integrated platform for precision medicine." In addition, the major stakeholders of medical institutions and companies were Seoul National University Hospital, Kangbuk Samsung Hospital, Ajou University Hospital, Samsung, and Vuno Inc. CONCLUSIONS: This analysis confirmed that the issues related to digital health care are largely composed of telemedicine, data, and health care business. For digital health care to develop as a national innovative growth engine and to be institutionalized, the development of a digital health care fee model that can improve the regulatory system and the cost-effectiveness of patient care, centering on the Ministry of Health and Welfare as a key stakeholder, is essential.

Anti-pollution skincare: Research on effective ways to protect skin from particulate matter.

While there is increasing interest in anti-pollution care to particulate matter (PM), there has been no research evaluating the efficacy of skin care products in a real-world setting. Our objective was to find effective ways to protect skin from PM. In total, 64 volunteers whose skin was classified as reactive to PM concentration in the previous study were enrolled. Through split-face study, different combinations of skin care products (barrier cream, barrier cream/micellar water, antioxidant, and antioxidant/micellar water) were applied for 4 weeks during the high-PM period. The biophysical properties were measured, and a facial analysis system was used to evaluate skin condition at days 0, 14, and 28. The concentrations of PM and daily events that may affect skin conditions were also recorded. The mean concentration levels of PM10 and PM2.5 from days 0 to 14 were higher in the barrier cream group than in the antioxidant group. For each group, aside from skin tone in the antioxidant/micellar water group, there were no statistically significant differences in skin measurements before and after the application, which reflects no aggravation in skin condition during high-PM periods. Intergroup analysis showed no differences in skin measurements among the four groups from day 0 to day 14, from day 14 to day 28, and from day 0 to 28. For anti-pollution care, maintaining skin barrier function using barrier cream seems to be sufficient in individuals sensitive to PM.

Initial conditioning and re-conditioning recruit different populations of 'fear neurons' in the basal amygdala of rats.

'Fear neurons' in the basal amygdala (Ba) acquire excitatory responsiveness to conditioned stimuli (CS) after fear conditioning and are believed to encode aversive valence of conditioned fear. However, it is unclear whether identical fear conditioning sessions given at different times engage the same population of 'fear neurons'. Here, we recorded electrical activity from single neurons in the Ba while the same fear conditioning paradigm was performed at two different times. Conditioned fear was monitored during CS presentation after each conditioning session in order to identify 'fear neurons'. Surprisingly, we found that initial conditioning and re-conditioning recruited different populations of 'fear neurons' in the Ba. We performed a control experiment in which conditioned fear was monitored twice after a single fear conditioning session. The majority of the 'fear neurons', which were activated during the first retrieval, were re-activated during the second retrieval, suggesting that conditioning-induced 'fear neurons' are stable. Our findings, therefore, suggest that 'fear neurons' in the Ba encode specific learned events as well as their aversive valence.

Fear renewal requires nitric oxide signaling in the lateral amygdala.

Fear renewal is defined as return of the conditioned fear responses after extinction when a conditioned stimulus (CS) is given outside of the extinction context. Previously, we have suggested that extinction induces S-nitrosylation of GluA1 in the lateral amygdala (LA), and that the extinction-induced S-nitrosylation of GluA1 lowers the threshold of GluA1 phosphorylation (at Ser 831) which is required for fear renewal. This fits nicely with the fact that fear renewal is induced by weak stimuli. However, it has not been tested whether S-nitrosylation of GluA1 in the LA is indeed required for fear renewal. In the present study, we used three different chemicals to impede protein S-nitrosylation via distinct mechanisms. Fear renewal was inhibited by microinjection of 7-Nitroindazole (nNOS inhibitor), and ZL006 (a blocker of PSD-95-nNOS interaction) before fear renewal. Furthermore, fear renewal was also attenuated by microinjection of a strong antioxidant (N-acetyl cysteine), which scavenges reactive oxygen including nitric oxide, into the LA before each extinction training. These findings suggest that protein S-nitrosylation is required for fear renewal.

Sex differences in the association between self-rated health and high-sensitivity C-reactive protein levels in Koreans: a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey.

BACKGROUND: No studies have investigated the association between self-rated health (SRH) and high-sensitivity C-reactive protein (hs-CRP) levels in South Koreans. We explored this association and analyzed differences between sexes. METHODS: Using cross-sectional data from the 2015-2017 Korea National Health and Nutrition Examination Survey, we analyzed the association between SRH and high hs-CRP levels (> 1.0 mg/L) in 14,544 Koreans aged ≥ 19 years who responded to the SRH survey and had available hs-CRP test results. Differences in sociodemographic factors were analyzed using the Pearson's chi-square test for categorical variables or the Mann-Whitney U test for continuous variables. Multiple logistic regression analysis was used to measure the association between hs-CRP levels and SRH according to sex while adjusting for other possible confounders. RESULTS: The percentage of very poor to poor SRH was higher in the high hs-CRP group (22.4%) than in the low hs-CRP group (17.66%). Among men, the risk of a high hs-CRP level increased with worse SRH (adjusted for confounders; P for trend < 0.001). After adjusting for all confounders, including chronic diseases, men with very poor SRH showed a higher odds ratio (OR) for high hs-CRP levels than those with very good SRH (fully adjusted OR, 1.74; 95% CI, 1.04-2.90). Significant correlations were absent among women. CONCLUSIONS: Poor SRH was correlated with low-grade inflammation (high hs-CRP levels) among Korean male adults. These findings could be useful for developing health improvement programs and in goal setting at a national scale.

Applicability assessment of empty fruit bunches from palm oil mills for use as bio-solid refuse fuels.

Palm kernel shells (PKS), empty fruit bunches (EFB), and trunks are by-products of the palm oil industry and form approximately 50 wt % of fresh fruit bunch (FFB). In particular, EFB accounts for approximately 20 wt % of FFB. Although large amounts of EFB are generated from palm oil mills every year in Indonesia and Malaysia, EFB is treated as waste because commercial technologies for thermo-chemical conversion of EFB into renewable energy are still under development. A robust conversion method can transform EFB into an appealing renewable energy source. In order to secure this renewable energy source, Korea can import EFB as biomass. This paper investigates literature on the status of utilization of EFB, by-products from palm oil mills in order to identify the best available technological process to use EFB as bio-solid refuse fuels (SRF). Meanwhile, physico-chemical analyses (proximate, elemental, and calorific value analyses), biomass and heavy metal content were measured in order to assess whether EFB would be suitable for use as a bio-SRF, in accordance with the Korean quality standard for SRF. According to the analysis results, EFB showed applicability to use as bio-SRF; main analysis results - moisture (9.63 wt %), ash (5.94 wt %), biomass content (97.82 wt %) and calorific value (3668 kcal kg).

Postoperative Delirium in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting According to the Anesthetic Agent: A Retrospective Study.

OBJECTIVE: To evaluate the effect of two anesthetic agents (sevoflurane or propofol) on postoperative delirium (POD) in patients undergoing off-pump coronary artery bypass grafting (CABG). DESIGN: Retrospective observational design. SETTING: University hospital. PARTICIPANTS: Two hundred ninety-two patients undergoing off-pump CABG who were anesthetized with sevoflurane or propofol. METHODS: Incidence of POD, laboratory data, and pre-, intra-, and 24-hour postoperative clinical variables were reviewed retrospectively. The independent predictors of POD were evaluated. MEASUREMENTS AND MAIN RESULTS: The cumulative incidence of POD after off-pump CABG was 10.6% (31 of 292 patients) and the incidence rates of POD were not statistically significant in the sevoflurane and propofol groups (13% [20 of 156 patients] and 8% [11 of 136 patients], respectively; p = 0.137). Other variables, including the laboratory and clinical data also did not differ significantly between the anesthetic groups. Age ≥75 years (odds ratio [OR], 4.84; 95% confidence interval [CI], 1.44-16.27; p = 0.011), postoperative pneumonia (OR, 10.84; 95% CI, 3.32-35.34; p < 0.001), 6 or more packed red blood cell units transfusion in the first 24 hours postoperatively (OR, 5.30; 95% CI, 1.32-21.27; p = 0.019), and 24-hour postoperative albumin <3.0 g/dL (OR, 3.38; 95% CI, 1.20-9.31; p = 0.021) were independent predictors of POD after off-pump CABG. CONCLUSIONS: The incidence of POD in patients undergoing off pump-CABG did not differ between those receiving sevoflurane versus propofol-based anesthesia.

Scattered atypical melanocytes with hyperchromatic nuclei in the nail matrix: diagnostic clue for early subungual melanoma in situ.

BACKGROUND: The lack of highly specific clinical and histopathological criteria has contributed to the delay in diagnosis of subungual melanoma in situ in its early stages. METHODS: Eighteen cases of subungual melanoma in situ, the largest series reported to date, were analyzed to characterize the clinical and histopathological findings of early stages of subungual melanoma in situ along with five cases of nail matrix nevus and five cases of subungual lentigo serving as histologic control. RESULTS: Clinically, longitudinal melanonychia was present in all 18 cases of subungual melanoma in situ, consisting of irregular dark brown to black streaks within a brown background with (11 cases) or without Hutchinson's sign. Histopathologically, variable shaped and sized, hyperchromatic nuclei surrounded by retraction artifact were present in all cases. Nine cases showed a significant increase in the number of atypical melanocytes with marked nuclear atypia, while the rest of the cases showed less noticeable changes in nail matrix including lower density of melanocytes and/or mild nuclear atypia. In 15 cases, the nuclear enlargement in some of the melanocytes was greater than two times that of the neighboring matrix cells. In the remaining three cases, the nuclei were enlarged to a much lesser degree. All cases displayed areas of haphazard and uneven distribution of solitary melanocytes and, although not observed in all cases, some degree of pagetoid spread was present in majority of the cases. In contrast, nail matrix nevi showed well-formed nests consisting of relatively monomorphous melanocytes with abundant cytoplasm and subungual lentigos consisted of subtle increase in the number of dendritic melanocytes in solitary units within the lower layers of the nail matrix. CONCLUSION: Increase in the number of scattered atypical melanocytes with large hyperchromatic nuclei in a partial nail matrix may provide a diagnostic clue to subungual melanoma in situ in concert with its clinical suspicion.

Bioengineering toolkits for potentiating organoid therapeutics.

Organoids are three-dimensional, multicellular constructs that recapitulate the structural and functional features of specific organs. Because of these characteristics, organoids have been widely applied in biomedical research in recent decades. Remarkable advancements in organoid technology have positioned them as promising candidates for regenerative medicine. However, current organoids still have limitations, such as the absence of internal vasculature, limited functionality, and a small size that is not commensurate with that of actual organs. These limitations hinder their survival and regenerative effects after transplantation. Another significant concern is the reliance on mouse tumor-derived matrix in organoid culture, which is unsuitable for clinical translation due to its tumor origin and safety issues. Therefore, our aim is to describe engineering strategies and alternative biocompatible materials that can facilitate the practical applications of organoids in regenerative medicine. Furthermore, we highlight meaningful progress in organoid transplantation, with a particular emphasis on the functional restoration of various organs.

Effectiveness of artificial intelligence in detecting and managing depressive disorders: Systematic review.

OBJECTIVES: This study underscores the importance of exploring AI's creative applications in treating depressive disorders to revolutionize mental health care. Through innovative integration of AI technologies, the research confirms their positive effects on preventing, diagnosing, and treating depression. The systematic review establishes an evidence base for AI in depression management, offering directions for effective interventions. METHODS: This systematic literature review investigates the effectiveness of AI in depression management by analyzing studies from January 1, 2017, to May 31, 2022. Utilizing search engines like IEEE Xplore, PubMed, and Web of Science, the review focused on keywords such as Depression/Mental Health, Machine Learning/Artificial Intelligence, and Prediction/Diagnosis. The analysis of 95 documents involved classification based on use, data type, and algorithm type. RESULTS: The study revealed that AI in depression management excelled in accuracy, particularly in monitoring and prediction. Biomarker-derived data demonstrated the highest accuracy, with the CNN algorithm proving most effective. The findings affirm the therapeutic benefits of AI, including treatment, detection, and disease prediction, highlighting its potential in analyzing monitored data for depression management. LIMITATIONS: This study exclusively examined the application of AI in individuals with depressive disorders. Interpretation should be cautious due to the limited scope of subjects to this specific population. CONCLUSIONS: To introduce digital healthcare and therapies for ongoing depression management, it's crucial to present empirical evidence on the medical fee payment system, safety, and efficacy. These findings support enhanced medical accessibility through digital healthcare, offering personalized disease management for patients seeking non-face-to-face treatment.

Exploring the Relationship between Fundamental Movement Skills and Health-Related Fitness among First and Second Graders in Korea: Implications for Healthy Childhood Development.

This study investigated the relationship between fundamental movement skills (FMSs) and health-related fitness (HRF) among first and second graders in South Korean elementary schools. It aimed to provide foundational data for developing physical education programs tailored to the motor development stages and fitness levels of younger elementary school students. This study utilized secondary data from the physical activity competence evaluation conducted by the Health Physical Activity Institute (HPAI). In October 2023, the HPAI evaluated the fundamental movement skills (jumping, running, hopping, static balance, dynamic balance, overhand throwing, and kicking) and health-related fitness (muscular strength, cardiorespiratory endurance, and flexibility) of 291 first and second-grade students. The collected data were analyzed through frequency and multiple regression analyses performed using SPSS software. The results revealed that higher scores in jumping and hopping are associated with greater muscular strength, cardiorespiratory endurance, and flexibility. Running had no significant effect on HRF elements. Higher scores in static balance (i.e., that used in single-leg stance) were associated with increased muscular strength, cardiorespiratory endurance, and flexibility, but dynamic balance (balance beam walking) did not have a significant effect. Higher scores in overhand throwing were associated with greater muscular strength and cardiorespiratory endurance, but kicking did not show a significant association. Overall, these findings emphasize the importance of prioritizing jumping and static balance in physical education for the well-rounded health development of first and second graders. Based on the results derived from this study, it is expected to serve as a theoretical basis for including "jumping" and "static balance" in the first and second grade curriculum of elementary schools, thereby providing essential guidance.

Exploring signals of myopathy associated with statin and contraindicated comedications in the realworld.

BACKGROUND: Using statins in combination with other drugs was reported to increase the risk of myopathy. However, there was a sparse number of studies on the incidence of adverse events (AEs) associated with the concomitant use of statin and contraindicated drugs in the real world. OBJECTIVES: This study aimed to identify the risk of concomitant use of statins with contraindicated drugs by exploring signals related to statin-drug interactions. METHODS: We performed a disproportionality analysis for drugs and AEs by applying the case/non-case study using the KIDS-KAERS database (KIDS-KD), 2016-2020. A case was defined as an individual case safety reports (ICSRs) including "rhabdomyolysis/myopathy." A non-case was defined as an ICSR, including all other AEs. We applied Ω shrinkage measure model, chi-square statics model, additive model, multiplicative model, and combination risk ratio model to detect signals of myopathy due to statin with concomitant drugs including antiviral agents, immunosuppressants, and antifungals. RESULTS: Among 1 011 234 ICSRs, 2708 were cases, with 861 cases of statin monotherapy and 1248 of concomitant uses of statin. The adjusted reporting odds ratios were 3.27 (95% confidence interval [CI]: 3.11-3.43), 8.70 (95% CI: 8.04-9.40), and 1.83 (95% CI: 1.73-1.94), respectively. Several combinations of signals were detected through an additive model or multiplicative model. CONCLUSION: Signals of an increased risk of myopathy associated with the use of statins with concomitant drugs, including contraindicated drugs, were confirmed in a real-world setting.

Changes in the Average Body Mass Index of Fifth- and Sixth-Grade Korean Elementary School Students: The Role of Physical Education in Student Health.

This study aimed to emphasize the importance of physical education in maintaining sufficient physical activity by examining the average BMI of fifth- and sixth-grade elementary school students in Korea over multiple years. This study investigated changes in the average BMI of fifth- and sixth-grade elementary school students in Korea. It provided foundational data to suggest the role of physical education in student health and set future directions. The 2019-2021 Physical Activity Promotion System (PAPS) of the Korean Ministry of Education was used. Data corresponding to fifth- and sixth-grade students (124,693 from 2019, 126,226 from 2020, and 117,809 from 2021) in 1208 elementary schools in Korea were collected. Repeated measures ANOVA was conducted for the data analysis. The study findings are as follows: First, the average BMI of fifth- and sixth-grade elementary school students in Korea increased significantly in 2021 compared with 2019 and 2020. Second, changes in the yearly average BMI showed a significant difference depending on gender and grade. Obesity among fifth- and sixth-grade elementary school students in Korea increased steadily during 2019-2021, which may be due to a decrease in students' physical activity. Male students showed a steeper increase regardless of grade. During the study period, limited physical activity at school increased obesity rates. Physical education must play a role in students' health in preparation for future changes.