Background: Preclinical studies have reported anticancer properties of sodium-glucose cotransporter 2 inhibitors (SGLT2is). We aimed to elucidate the association between the use of SGLT2is and the risk of prostate cancer among male patients with type 2 diabetes mellitus (T2DM). Methods: An active-comparator, new-user cohort design using a nationwide database between September 2014 and June 2020 was conducted on 45,601 new SGLT2i users and 205,395 new users of other glucose-lowering medications (oGLMs). In the following 1:1 propensity score matched (PSM) analysis, 35,371 SGLT2i users matched with an equivalent number of oGLM users were assessed. The hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer were calculated. Results: Among the cohort, prostate cancer was diagnosed in 210 out of 45,601 SGLT2i users, corresponding to a cumulative incidence of 1.0%, in contrast to 1,880 cases among 205,395 users of oGLMs, with a cumulative incidence of 1.5%. The use of SGLT2is was significantly correlated with a reduced risk of prostate cancer based on a multivariable-adjusted HR of 0.83 (95% CI, 0.71 to 0.98). PSM analysis affirmed 18% reduction in prostate cancer risk associated with SGLT2i use (HR, 0.82; 95% CI, 0.67 to 0.99). Subgroup analyses revealed that body mass index (BMI) significantly influenced the effect of SGLT2i on prostate cancer risk, with a more pronounced reduction in the subgroup with a BMI <25 kg/m2 (P=0.037). Conclusion The use of SGLT2is in Korean male patients with T2DM is associated with a lower risk of prostate cancer.

Background: and Purpose To compare the epidemiological and clinical features of the rare patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) with age- and sex-matched controls in a nationwide cohort from South Korea. Methods: This observational cohort study analyzed newly diagnosed CADASIL patients aged at least 20 years and matched controls using data from the National Health Information Database for 2004–2022. The cumulative incidence of CADASIL was assessed by age and sex, and compared between regions. Neurologic and systemic diseases were compared between the CADASIL and control groups. Results: The study analyzed 816 CADASIL patients and 816 age- and sex-matched controls aged 56.8±15.2 years (mean±standard deviation), among whom 48.3% were male. The cumulative incidence of CADASIL was 1.86 per 100,000 people (95% confidence interval [CI]=1.85– 1.87 per 100,000), and peaked at 60–69 years of age. In terms of regional distribution, the incidence was highest for Jeju, at 39.67 per 100,000 (95% CI 37.84–41.49 per 100,000). Neurologic diseases were more frequent in CADASIL patients, including Alzheimer’s disease (33.1% vs.20.0%), vascular dementia (84.9% vs. 5.0%), epilepsy (34.6% vs. 15.9%), stroke (70.7% vs. 27.6%), parkinsonism (18.9% vs. 11.0%), and depression (60.8% vs. 44.9%). Systemic diseases such as diabetes mellitus (78.9% vs. 68.9%) were also more common in CADASIL patients, while cancer (27.9% vs. 38.7%) and myocardial infarction (10.0% vs. 13.6%) were less common than in controls. The onset ages of all diseases were lower in CADASIL patients. Conclusions This study has provided a precise nationwide estimate of the CADASIL incidence and its regional distribution in South Korea. CADASIL patients showed higher incidence rates and earlier onsets of diverse clinical manifestations.

Although aspartate aminotransferase (AST) is a serum marker of hepatocellular damage in chronic hepatitis, it is difficult to interpret very high AST levels with concurrent low alanine aminotransferase (ALT) levels. Macro-AST is an immunoglobulin-AST complex that can present as aberrant high enzymatic activity without significant inflammation in the liver. Two patients with chronic hepatitis B presented with disproportionate AST elevations. Their plasma samples were precipitated with polyethylene glycol (PEG) and stored at 4°C for macro-AST determinations. In Case 1, PEG precipitation showed 100% removal of AST activity, and refrigerated storage resulted in a ~70% decline over seven days, confirming macro-AST. In Case 2, both tests showed minimal changes, suggesting that macro-AST was unlikely. The AST levels normalized after antiviral therapy, suggesting immune-active hepatitis as the probable cause, but the other contributing factors could not be completely excluded. The abrupt decrease in AST activity after PEG precipitation and during refrigeration storage suggests that relatively high AST values compared to ALT might be attributed to the presence of macro-AST.These non-invasive methods for detecting macroenzymes might help the patient avoid unnecessary further work-ups.

The rapid evolution of obesity therapeutics, led by glucagon-like peptide-1 receptor agonists (GLP-1RAs) and metabolic surgery, has achieved unprecedented weight loss. However, the skeletal consequences of such substantial weight reduction are of increasing clinical concern. This review explores the relationship between obesity, weight-loss modalities, and bone health. While obesity was historically viewed as bone-protective due to mechanical loading, recent evidence highlights qualitative bone deterioration and sitespecific fracture risks. Intentional weight loss through caloric restriction or bariatric surgery consistently accelerates bone turnover and reduces bone mineral density (BMD), with surgical interventions showing the most significant impact. Emerging data on GLP-1RAs suggest modest BMD declines, largely proportional to weight loss and likely driven by mechanical unloading. Conversely, preclinical studies indicate that GLP-1 signaling may exert direct osteoanabolic and anti-resorptive effects. To preserve skeletal integrity, obesity management must shift toward a holistic body composition framework. Integrating structured resistance exercise, optimizing nutrition (calcium, vitamin D, and protein), and implementing skeletal monitoring in high-risk individuals are essential. Future obesity care should prioritize the maintenance of bone quality and lean mass alongside fat reduction to ensure long-term skeletal resilience and prevent fragility fractures.

Background and Objectives: Graves’ ophthalmopathy (GO) is an autoimmune inflammatory disorder that can adversely affect quality of life in patients with Graves’ disease (GD). The objective of this study was to characterize the clinical features of patients with GO and to identify risk factors associated with its development and the need for anti-inflammatory treatment. Materials and Methods: In this multicenter, retrospective observational study, 818 patients with GD were identified via electronic medical record review. Clinical characteristics were assessed, and logistic regression analyses were performed to identify risk factors for GO development and the need for anti-inflammatory treatment. Results: Among the 818 patients with GD, 135 (16.5%) developed GO, and 60 (7.3%) of these patients received anti-inflammatory treatment. GO was diagnosed at the time of GD diagnosis in 54.8% of cases, and proptosis and eyelid/orbital swelling were the common presenting features. In multivariable analysis, female sex (odds ratio [OR]: 1.75, confidence interval [CI]: 1.02-3.03), goiter (OR: 1.71, CI: 1.08-2.71), and smoking (ex-smokers: OR, 2.18; 95% CI: 1.02-4.65; current smokers: OR, 3.11; CI, 1.78-5.44) were independently associated with GO development, whereas diabetes (OR: 0.35, CI: 0.14-0.89) was inversely associated. Higher total cholesterol (OR: 1.31, CI: 1.01-1.04) and elevated thyrotropin-binding inhibitory immunoglobulin levels (OR: 1.07, CI: 1.02-1.11) were also significantly associated with the need for anti-inflammatory treatment. Conclusion This study delineated the clinical features of GO and identified risk factors for its development and the need for anti-inflammatory treatment in patients with GD, providing valuable information for the management of GO in Korean patients.

Vaccines are highly effective, but rare or delayed adverse events following immunization (AEFIs) require post-licensure surveillance beyond clinical trials. Korea lacks a comprehensive, active, database-based framework, yet key assets exist: nationwide claims databases (National Health Insurance Service/Health Insurance Review and Assessment Service), the national immunization registry (Korea Disease Control and Prevention Agency’s Immunization Registry Information System) for National Immunization Program (NIP) and non-NIP vaccines, and increasingly standardized hospital electronic health records.We propose a federated, code to data architecture with data linkages between these data.Implementation should adopt a common data model (CDM), standardized case definitions, latency accounting, and transparent public reporting under strong privacy governance. Major challenges include multi step administrative approvals for data linkage, incomplete capture of adult non-NIP vaccinations, heterogeneous hospital data structures, and strict data protection constraints. Strategic priorities are to streamline statutory and administrative processes for public health use, mandate or enable claims-based capture of adult vaccinations, enhance CDM based interoperability, and develop secure hubs for aggregated outputs. With these measures, Korea will be well positioned to establish a scalable active surveillance system capable of detecting rare AEFIs, supporting transparent and evidence-based communication, and ensuring equitable injury compensation grounded in domestic data.

Neuropathic pain markedly impairs quality of life and imposes a substantial socioeconomic burden, while available treatments often provide only partial relief and are limited by safety concerns. The Neuropathic Pain Special Interest Group of the International Association for the Study of Pain (NeuPSIG-IASP) first published pharmacologic recommendations in 2007, followed by a major update in 2015 and a new guideline in 2025. This narrative review specifically compares the 2015 and 2025 NeuPSIG-IASP guidelines, outlining key methodological changes and therapeutic shifts. The 2025 guideline is based on a larger, more rigorous meta-analysis, maintains α2δ-ligands (adds mirogabalin), serotonin-noradrenaline reuptake inhibitors, and tricyclic antidepressants as first-line drugs, downgrades tramadol into the opioid third-line group. It also introduces high-frequency motor-cortex repetitive transcranial magnetic stimulation as a weakly recommended third-line option and discusses implications for Korean clinical practice.

Background: Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP. Methods: From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days). Results: Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days. Conclusions The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.

This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

Myopia, particularly high myopia, is a significant risk factor for several ocular pathologies including cataract, glaucoma, and retinal detachment. Excessive axial elongation associated with high myopia can induce biomechanical stretching, increasing the risk of serious complications like posterior staphyloma and myopic maculopathy. Global meta-analyses estimate that approximately 10 million people were visually impaired due to myopic maculopathy in 2015, with 3 million being blind. Recent nationwide surveys in South Korea revealed a prevalence of 65.4% for myopia and 6.9% for high myopia in children and adolescents, highlighting the urgent need for effective management. Delaying the onset and slowing the progression of myopia during childhood and adolescence is crucial for reducing the potential lifetime risk of these complications. This consensus statement, prepared by the Korean Myopia Society for the Korean Association for Pediatric Ophthalmology and Strabismus (KAPOS), reviews the current evidence for myopia control interventions and provides management strategies applicable to the South Korean clinical setting. Key interventions covered include lifestyle modifications (outdoor time, near work adjustment), optical methods (myopia-control spectacle lenses, dual-focus soft contact lenses, orthokeratology), and pharmacologic treatment (low-concentration atropine), as well as combination therapies. The statement also addresses patient selection, treatment outcome evaluation using spherical equivalent and axial length changes, and the crucial aspects related to treatment cessation and the rebound effect.