Korean National Health Insurance Service Research Articles

In February 2024, South Korea experienced a major healthcare disruption following the mass resignation of approximately 86% of resident physicians in protest of a government-led medical reform. In response, the government introduced a policy that centralized high-complexity operations in tertiary hospitals and redirected low-complexity procedures to general hospitals and clinics. However, the nationwide impact of this policy on surgical distribution and volume remains unclear. A retrospective analysis was performed using nationwide claims data from the Korean National Health Insurance Service, accessed via the Health Insurance Review and Assessment Service (HIRA). General thoracic surgery volumes from February to July 2023 (pre-crisis) were compared to the same period in 2024 (post-crisis) across tertiary hospitals (n=47), general hospitals (n=331), and smaller hospitals/clinics (n=37,888). Surgical complexity was categorized using relative value units (RVUs), which reflect procedural intensity and resource requirements. Overall thoracic surgery volume declined by 15% during the crisis. Tertiary hospitals reported a 22% reduction in procedures, while general hospitals and clinics recorded increases of 9% and 92%, respectively. High-complexity operations (≥30,000 RVUs) at tertiary hospitals fell by 22%, with only partial compensation by general hospitals. Low-complexity procedures (<30,000 RVUs) also decreased at tertiary hospitals but were not adequately redistributed. The 2024 healthcare crisis caused significant disruption to surgical capacity in South Korea. Although some redistribution occurred, the government's reallocation strategy did not fully achieve its intended goals. Recovery of pre-crisis surgical capacity, especially for high-complexity procedures, remains incomplete.

Background: While early surgical repair in tetralogy of Fallot (TOF) is increasingly favored, the long-term impact of surgical strategy—particularly on extracardiac organs—remains unclear. This study aimed to compare neurologic, pulmonary, renal, hepatic, and developmental outcomes between initial total correction and staged repair in neonates with TOF. Methods: We analyzed data from the Korean National Health Insurance Service database (2005–2021), including all infants diagnosed with TOF within the first year of life. Patients were grouped by surgical strategy: (1) initial total correction within 30 days of diagnosis and (2) staged repair, defined as PDA stent or shunt followed by total correction. Primary outcomes were extracardiac complications identified by ICD-10 codes. Multivariable Cox regression models were used to estimate adjusted hazard ratios (HRs), with subgroup analyses for patients undergoing intervention within 1 and 3 months of diagnosis. Results: Among 2,496 patients who underwent total correction, the staged repair group had significantly higher risks of neurologic (HR 6.08; 95% CI, 3.43–10.78), renal (HR 9.95; 95% CI, 4.79–20.66), and developmental (HR 1.70; 95% CI, 1.42–2.03) complications compared to the initial correction group. These associations persisted across early intervention subgroups. Pulmonary and hepatic complications showed no significant difference. Independent predictors of adverse outcomes included low birth weight and presence of genetic disorders. Conclusions: In this nationwide study, staged repair in TOF was associated with substantially greater long-term risk of renal, neurologic, and developmental complications, even in infants requiring early intervention. These findings support consideration of extracardiac morbidity—not just cardiac survival—when selecting surgical timing in TOF.

BACKGROUND: The association between breast cancer diagnosis, treatment, and the risk of incident ischemic stroke remains unclear. We aimed to investigate ischemic stroke risk among breast cancer survivors and evaluate the association by age, follow-up duration, and cancer treatments. METHODS: Using the Korean National Health Insurance Service database, we studied 113,232 women newly diagnosed with breast cancer (aged ≥18 years) without prior stroke history who underwent breast cancer surgery between January 2010 and December 2016. Each was matched 1:3 by birth year to a cancer-free female population (n=322,818). Subdistribution hazard ratios (sHRs) and 95% confidence intervals (CIs) were estimated, accounting for death as a competing risk and adjusting for sociodemographic factors and cardiovascular and noncardiovascular comorbidities. RESULTS: Over a mean follow-up of 7.2 years, ischemic stroke occurred in 1,155 (1.0%) breast cancer surgery survivors. Overall, breast cancer survivors had a slightly lower risk of stroke than cancer-free women (sHR 0.94; 95% CI 0.88–1.00). However, stroke risk was elevated in the short term following diagnosis (sHR 1.59, 95% CI 1.34–1.89 at 1 year; sHR 1.17, 95% CI 1.05–1.30 at 3 years) across all age groups, with stronger associations observed at 3 and 6 months post-diagnosis. A reduced risk was observed after 1 year in a landmark analysis that included only individuals event-free at the 1-year follow-up (sHR 0.87, 95% CI 0.81–0.93). Among breast cancer survivors, treatment with anthracycline (sHR 1.25) and the combination of tamoxifen and aromatase inhibitors (sHR 1.49) were associated with increased stroke risk, whereas radiation therapy was associated with decreased risk (sHR 0.84). These associations weakened and became nonsignificant after 1 year. Stroke risk was also higher in breast cancer survivors with low income, hypertension, diabetes, or current smoking. CONCLUSION: The association between breast cancer and ischemic stroke risk is time-dependent, with increased short-term risk post-diagnosis and treatment, followed by a decline over time. These findings highlight the importance of proactive stroke risk management, including baseline cardiovascular assessments and ongoing monitoring for thromboembolic events.

Background: Obstructive sleep apnea (OSA) is increasingly recognized as a risk factor for cardiovascular diseases. However, long-term population-based data evaluating its association with a spectrum of cardiovascular outcomes, particularly conduction system disorders, remain limited. Objective: We investigated the 15-year cardiovascular outcomes in patients with OSA using a large-scale nationwide cohort. Methods: We conducted a retrospective cohort study using the Korean National Health Insurance Service database, including 547,749 patients diagnosed with OSA and 2,282,415 matched controls between 2002 and 2020. Following exclusion criteria and 1:1 propensity score matching, 541,812 individuals were included in each group. The primary outcomes were incidence of atrial fibrillation (AF), premature beats, ventricular arrhythmias, atrioventricular block, sinus node dysfunction, heart failure, ischemic heart disease (IHD), and stroke. Cumulative incidence was assessed using Kaplan–Meier survival curves. Hazard ratios (HR) were estimated using Cox proportional hazards models adjusted for relevant covariates. Results: Over a 15-year follow-up period, the OSA group exhibited significantly higher incidence rates of all cardiovascular outcomes than the control group. In the matched cohort, adjusted HR were elevated for AF (1.82 [1.77–1.87]), premature beats (2.25 [2.17–2.34]), ventricular arrhythmias (1.81 [1.64–1.99]), AV block (1.81 [1.64–1.99]), sinus node dysfunction (2.22 [1.96–2.50]), heart failure (1.43 [1.39–1.48]), IHD (1.54 [1.52–1.56]), and stroke (1.20 [1.18–1.22]) (all p &lt; 0.0001). The incidence of conduction disorders, AV block, and sinus node dysfunction nearly doubled in the OSA group. Conclusion: OSA was independently associated with an increased long-term risk of various cardiovascular outcomes, including arrhythmias, ischemic events, and conduction system disorders. This supports the importance of early identification and longitudinal management of cardiovascular risk in this population.

Introduction: Data are scarce regarding the long-term impact of physical activity (PA) change on new and recurrent ischemic events following myocardial infarction (MI). We hypothesized that increased PA was associated with a lower risk of major adverse cardiovascular events (MACE) after MI. Methods: From the Korean National Health Insurance Service database, we identified all incident cases of acute MI in 2009–2019 and included adults aged ≥19 years at first MI who underwent health examinations during a pre-MI look-back and a 2-year post-MI landmark period (Figure A). PA was self-reported at each examination using a modified International PA Questionnaire and was categorized as 0 metabolic equivalent of task (MET)-min/week (inactive), 1–599 MET-min/week (active but not meeting guideline), or ≥600 MET-min/week (active, meeting guideline), or modeled continuously using restricted cubic splines. Primary outcome was the first occurrence of MACE (composite of all-cause death, stroke, or recurrent MI) after the landmark. Secondary outcomes included cardiovascular death, first occurrence of each component of MACE, and total (first and subsequent) occurrence (ie, recurrent event analysis) of MACE. Results: Over a median follow-up of 6.1 years after the 2-year landmark among 62,322 adults who had first MI (median age at landmark, 64 years; 20.3% women), 10,693 primary outcome events occurred. After multivariable adjustment, higher PA levels (1–599 or ≥600 MET-min/week) after first MI were associated with a lower risk of MACE (HR [95% CI]: 0.85 [0.81–0.89] and 0.76 [0.72–0.80], respectively) compared with 0 MET-min/week (Figure B). Participants who increased PA from 0 MET-min/week to 1–599 or ≥600 MET-min/week had a lower risk of MACE than those who remained inactive (HR [95% CI]: 0.85 [0.80–0.91] and 0.81 [0.75–0.87], respectively; Figure C). Conversely, participants who decreased PA from ≥600 MET-min/week to 1–599 or 0 MET-min/week had a higher risk of MACE than those who maintained PA (HR [95% CI]: 1.15 [1.02–1.30] and 1.29 [1.16–1.42], respectively). An inverse dose-response association was observed between PA change and the risk of MACE (Figure D). Findings were consistent for first and total occurrence of secondary outcomes. Conclusions: Increases in PA after MI were associated with a lower risk of MACE, whereas decreases in PA were associated with a higher risk. These findings highlight the importance of promoting PA for long-term secondary prevention after MI.

Background/Objectives: Over the past two decades, the incidence of breast cancer has been increasing in Korea, which is potentially attributable to longer life expectancies, Westernized lifestyles, and declining fertility rates. However, the contributions of modifiable metabolic and behavioral risk factors in Asian populations remain underexplored. This study aimed to assess the associations between health-related factors and incidence of breast cancer in a large Korean cohort. Methods: We analyzed data from the Korean National Health Insurance Service and included women who underwent health screening in 2009. Cases of breast cancer diagnosed between 2010 and 2021 were identified using medical claims and registration codes. The breast cancer cases were matched to controls in a 1:4 ratio based on age, income, and region of residence. Conditional logistic regression was used to calculate the adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for key exposures. Results: In total, 52,869 breast cancer cases and 211,476 matched controls were included. The peak age group at diagnosis was 50–54 years. Dyslipidemia was associated with a 12% increase in the risk of breast cancer across all age groups (95% CI, 1.10–1.14). In women ≥ 50 years of age, a dose–response relationship was observed between body mass index (BMI) and breast cancer risk: aORs were 1.04 (95% CI, 1.01–1.08) for overweight, 1.14 (95% CI, 1.11–1.17) for obesity class I (BMI ≥ 25 to &lt; 30 kg/m2), and 1.33 (95% CI, 1.26–1.41) for obesity class II (BMI ≥ 30 kg/m2). Conversely, being underweight was associated with a decreased risk (aOR, 0.81; 95% CI, 0.74–0.89). No consistent associations were observed with alcohol consumption, cigarette smoking, or the presence of diabetes mellitus. Conclusions: Postmenopausal obesity and dyslipidemia contribute to the risk of breast cancer among Korean women. Promoting healthy behaviors throughout life may support long-term risk reduction.

Parkinson's disease (PD) and breast cancer are both significant public health concerns, but limited studies have explored a potential link between them. This study aims to investigate the risk of PD among breast cancer survivors in South Korea. Data from the Korean National Health Insurance Service (2010-2016) were used to identify 71,924 breast cancer survivors, matched 1:3 to 122,331 women without cancer. Subdistribution HRs (sHR) for PD were calculated using competing risk models adjusted for sociodemographic factors and comorbidities. Lag analysis at 1, 3, and 5 years after diagnosis assessed PD risk beyond these time points. Over a mean follow-up of 7.1 years, 179 breast cancer survivors developed PD. Overall, there was no significant increase in PD risk compared with the general population [sHR, 0.91; 95% confidence interval (CI), 0.76-1.10]. However, younger survivors (age ≤ 50) showed a trend toward increased PD risk over time (sHR, 1.09; 95% CI, 0.58-2.05 at the 1-year lag period; sHR, 1.28; 95% CI, 0.64-2.58 at the 3-year lag period; and sHR, 1.49; 95% CI, 0.63-3.51 at the 5-year lag period). Treatment with chemotherapy, endocrine therapy, or radiotherapy was not associated with increased PD risk. Breast cancer survivors did not exhibit a significantly increased risk of PD overall. However, younger survivors showed a possible age-related elevation in risk over time. This is the first nationwide study to evaluate PD risk among breast cancer survivors. Findings suggest the need for further investigation into age-specific neurodegenerative risks in breast cancer survivorship.

Association between smoking status and suicide mortality in patients with type 2 diabetes: A nationwide population-based cohort study.

The risk of suicide mortality according to income dynamics assessed using health insurance premium data: A nationwide cohort study in Korea.

Background/Objectives: Pacemaker-associated heart failure (PaHF) is a recognized complication of chronic ventricular pacing, yet its long-term incidence and prognostic impact remain incompletely defined. Previous studies on PaHF have been largely limited by small sample sizes, single-center designs, and insufficient long-term or time-dependent analyses. We aimed to evaluate the incidence, clinical predictors, and mortality risk of PaHF in a nationwide real-world cohort. Methods: Using the Korean National Health Insurance Service database, we identified 32,216 patients who underwent de novo pacemaker implantation between 2008 and 2019 without prior heart failure. Results: During a median follow-up of 3.8 years, 4170 patients (12.9%) developed new-onset PaHF and 6184 (19.2%) died. PaHF was independently associated with increased all-cause mortality (adjusted hazard ratio [HR]: 3.11, 95% confidence interval [CI]: 2.93–3.32, p &lt; 0.001), even after accounting for immortal-time bias and relevant covariates. The incidence of PaHF and its associated mortality risk both peaked within the first six months post implantation and remained persistently elevated throughout follow-up; notably, PaHF-associated mortality showed a late resurgence. Sensitivity and subgroup analyses consistently demonstrated higher mortality among patients with PaHF across a wide range of clinical characteristics. Conclusions: In this large, nationwide cohort, the development of PaHF was associated with a substantial and sustained increase in mortality risk following pacemaker implantation. Given the persistent and dynamic nature of this risk, longitudinal monitoring of cardiac function and individualized pacing strategies may be warranted to mitigate long-term adverse outcomes. Additionally, these findings provide real-world benchmarks to guide future pacing strategies and surveillance efforts.

We evaluated the impact of diabetic retinopathy (DMR) on dementia using clinical data from the Korean National Health Insurance Service. A nationwide, population-based retrospective cohort of 784,205 individuals over the age of 45 was analyzed. DMR diagnoses were confirmed using diagnostic and procedure codes. Covariate data, such as age, sex, income level, visual acuity, systemic and ophthalmic comorbidities, and behavioral factors, were collected from health screenings and claims data. Participants were followed until December 2017, and dementia cases were identified through registered diagnostic codes and medication prescriptions. The association between DMR and dementia was assessed using a multivariable-adjusted Cox proportional hazards model. Over an average follow-up of 10.9 ± 2.7 years, 53,934 patients were newly diagnosed with dementia. Those with DMR had a significantly higher risk of developing dementia (HR = 2.74; 95% CI = 2.44–3.08) compared to those without DMR. The risk was notably higher in patients younger than 65 years (HR = 4.07; 95% CI = 3.35–4.94) than in those aged 65 and older (HR = 2.71; 95% CI = 2.37–3.11). These findings suggest that DMR significantly increases the risk of dementia, particularly in younger patients.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-21868-9.

Co-prescription of selective serotonin reuptake inhibitors (SSRIs) and second-generation antipsychotics is common in the management of schizophrenia. However, the real-world clinical impact of cytochrome P450 (CYP)-mediated drug-drug interactions (DDIs) remains unclear. We investigated whether the co-prescription of risperidone or aripiprazole with SSRIs that differ in their CYP2D6 inhibition potential is associated with an increased burden of extrapyramidal symptoms (EPS). Using the Korean National Health Insurance Service database (2002-2022), we identified 4100 patients with schizophrenia who were treated with one of four medication combinations: risperidone plus escitalopram (Risp+Esc; n = 1611), risperidone plus fluoxetine/paroxetine (Risp+CYP2D6i; n = 1051), aripiprazole plus escitalopram (Arip+Esc; n = 1025), or aripiprazole plus fluoxetine/paroxetine (Arip+CYP2D6i; n = 413). The primary outcome was the mean proportion of days covered (PDC) by anticholinergic agents, used as a proxy for EPS burden. Groups were compared using multivariate analysis of covariance, adjusting for confounders. The Risp+CYP2D6i group had a significantly higher mean PDC for anticholinergics compared with the Risp+Esc group (56.4% vs. 47.3%; F = 23.98, P<.0001). Conversely, no significant difference was observed between the Arip+CYP2D6i and Arip+Esc groups (26.1% vs. 28.6%; F = 1.47, P= .225). The use of zolpidem and mood stabilizers was also significantly higher in both CYP2D6i groups. Co-prescription of strong CYP2D6-inhibiting SSRIs with risperidone, but not aripiprazole, is associated with a significant increase in anticholinergic use, providing large-scale, real-world evidence of a clinically meaningful DDI. These findings underscore the importance of considering SSRI metabolic profiles to mitigate EPS risk in patients treated with risperidone.

Assessing the risk of colorectal cancer (CRC) after kidney transplantation (KT) in patients with endstage renal disease (ESRD) receiving dialysis is crucial to determine KT's risks and benefits. In Korea, the study results remain unclear. Therefore, using a nationwide health screening and claims database, this longitudinal study aimed to investigate CRC risk in KT recipients versus patients with ESRD receiving hemodialysis. This research recruited 65,154 participants (60,202 on dialysis vs. 4,955 with KT) from the database of the Korean National Health Insurance Service, which provides mandatory health insurance to all Korean citizens. These participants were followed up from the baseline to CRC development, loss of follow-up, or study completion. The landmark method was used to effectively control the immortal time bias. During the follow-up period, the incidence of CRC was 2.9 per 1,000 person-years in the dialysis group and 1.2 per 1,000 person-years in the KT group (p < 0.001). The mean time for CRC development in the dialysis and KT groups was 4.5 and 4.8 years, respectively. Compared with dialysis patients, the KT group obtained an adjusted hazard ratio of 0.54 for CRC (95% confidence interval, 0.42-0.71; p < 0.001). Landmark analysis showed that the 15-year cumulative CRC incidence was significantly higher in the dialysis group than in the KT group after landmark time points of 3 and 5 years (p < 0.0001). The risk of CRC after KT remained significantly lower than that of patients undergoing dialysis, even after landmark analysis.

Background Various comorbidities contribute to mortality in patients with Parkinson’s disease (PD). Although growing evidence demonstrates that chronic kidney disease (CKD) increases the risk of developing PD, the effect of CKD on all-cause mortality remains unclear. Methods We enrolled 59,293 patients aged ≥40 years with de novo PD between 2009 and 2015, using de-identified data from the Korean National Health Insurance Service. Cox proportional hazards regression analysis using the presence of CKD or proteinuria as a predictor was performed to investigate the association between CKD, proteinuria, and mortality. For sensitivity analysis, the degree of eGFR or proteinuria were used as predictors in place of CKD/proteinuria. Results Parkinson’s disease patients with CKD (hazard ratio [HR] = 1.240, 95% confidence interval [CI] 1.190–1.283) and proteinuria (HR = 1.543, 95% CI 1.457–1.634) had a higher risk of mortality, even after controlling for confounding factors. The degree of kidney dysfunction ( p &amp;lt; 0.001) and proteinuria ( p &amp;lt; 0.001) were associated with an increased HR for mortality. Furthermore, female patients with CKD were more vulnerable to mortality than male patients ( p for sex × CKD &amp;lt; 0.001); however, there was no sex-specific vulnerability of proteinuria to mortality ( p for sex × proteinuria = 0.603). Conclusion Chronic kidney disease and proteinuria were associated with a higher all-cause mortality in patients with PD in a dose-dependent manner. Furthermore, these results highlight that strategies for controlling kidney function are necessary to reduce mortality in patients with PD.

Objective The prevalence of depression is high among patients with end stage kidney disease (ESKD). To date, there has been limited investigation into the comparative effects of antidepressant in patients with ESKD. This study aims to explore the association between type of antidepressant, incidence of all-cause death, and hospitalization for major bleeding in patients with ESKD and depression.Methods This study utilized data obtained from the Korean National Health Insurance Service Database. Patients with ESKD were divided into two groups: those prescribed strong serotonin reuptake inhibitors (SRIs) and those prescribed weak or intermediate SRIs.Results Over a mean follow-up of 2.46 years, the strong SRI group had a lower risk of all-cause death (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.81–0.93) and hospitalization for major bleeding (HR 0.84, 95% CI 0.79–0.90) with no increased risk of bleeding-related death (HR 1.05, 95% CI 0.80–1.37) compared to the weak or intermediate SRI group. The protective effects of strong SRI use for all-cause death and hospitalization for major bleeding remained consistent in those prescribed SSRIs for less than 120 days (death: HR 0.85, 95% CI 0.80–0.92; hospitalization for major bleeding: HR 0.84, 95% CI 0.78–0.90), and in patients aged below 75 years (death: HR 0.83, 95% CI 0.76–0.90; hospitalization for major bleeding: HR 0.81, 95% CI 0.75–0.87).Conclusion In patients with ESKD and depression, the use of strong SRIs was associated with a reduced risk of all-cause death and major bleeding hospitalization compared to the use of weak or intermediate SRIs.

We investigated the relationship between incidence of gastrointestinal tract cancers, metabolic dysfunction-associated steatotic liver disease (MASLD), and alcohol-related steatotic liver disease in diabetic population. A nationwide cohort of 2,616,828 individuals with diabetes under Korean National Health Insurance Service from 2015 to 2016 was divided into four subgroups: no steatosis (group 1), MASLD alone (group 2), MASLD with heavy alcohol intake (group 3), and alcoholic liver disease (group 4). We used fatty liver index to assess the probability of hepatic steatosis using cutoff scores of 30 and 60. We analyzed incidences of esophageal, stomach, colorectal, biliary, and pancreatic cancers until 2022. Compared with group 1 (reference), group 2 showed increased hazard ratios for stomach, colorectal, and biliary cancers, with a decreased hazard ratio for esophageal cancer (adjusted hazard ratio [95% confidence interval]: 1.10 [1.06–1.13], 1.13 [1.10–1.16], 1.10 [1.05–1.16], 0.88 [0.79–0.97], respectively). Probability of hepatic steatosis was positively correlated with all gastrointestinal tract cancers except esophageal cancer in non-drinkers, but only with stomach, colorectal, and biliary cancers in mild drinkers (ptrend < 0.001). In conclusion, MASLD increases gastrointestinal tract cancer risk, except esophageal cancer, in diabetic population. For non or mild drinkers, probability of hepatic steatosis serves as a predictor of gastrointestinal tract cancer risk.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-21005-6.

Immunoglobulin G4–related disease (IgG4-RD) is a chronic inflammatory condition that has been suggested to increase cancer risk, but the incidence and types of associated malignancies remain unclear. This study aimed to evaluate the cancer risk in patients with IgG4-RD using a nationwide population-based cohort. We identified 2,150 patients newly diagnosed with IgG4-RD between January 2012 and December 2020 from the Korean National Health Insurance Service database. Patients were followed until the occurrence of cancer, death, or December 31, 2021. Standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated to compare cancer incidence in IgG4-RD patients with that in the general population. Subgroup analyses were conducted based on sex, age at diagnosis, follow-up duration, and use of immunosuppressive agents. Patients with IgG4-RD had a significantly increased risk of overall cancer (SIR 4.12, 95% CI 3.48–4.85), including solid tumors (SIR 3.33, 95% CI 2.74–4.02) and hematologic malignancies (SIR 15.31, 95% CI 10.17–22.13). Among solid tumors, the highest risks were observed for pancreatic cancer (SIR 14.54, 95% CI 8.31–23.62), central nervous system cancer, and biliary tract cancer. Myelodysplastic syndrome and non-Hodgkin lymphoma were the most frequent hematologic cancers. Cancer risk was higher in female patients. The risk peaked within the first year after IgG4-RD diagnosis (SIR 7.13, 95% CI 5.65–8.89). Patients with IgG4-RD have a significantly elevated risk of developing cancer, particularly myelodysplastic syndrome, non-Hodgkin lymphoma, pancreatic cancer, and biliary tract cancer. Close surveillance for malignancy is warranted, especially during the first year after diagnosis. Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-21176-2.

ABSTRACTBackgroundLongitudinal evidence of the relationship between blood pressure (BP) variability and end‐stage kidney disease (ESKD) among individuals with type 2 diabetes is limited. Therefore, we evaluated the association between BP variability and ESKD in Korean adults with type 2 diabetes.MethodsThe study utilized data from the Korean National Health Insurance Service database, comprising health checkups conducted between 2004 and 2015. We enrolled 36 421 adults aged ≥ 19 years with type 2 diabetes who underwent at least two health checkups and were followed up until the end of 2017. BP variability was measured using the coefficient of variation, standard deviation, and variability independent of the mean. Hazard ratios (HRs) and 95% confidence intervals (CIs) for ESKD were determined using multivariate Cox proportional hazards regression analysis.ResultsDuring a median follow‐up of 8.05 years, 290 patients with ESKD were identified. The highest quartile of systolic or diastolic BP variability presented a higher risk of ESKD than did the lowest quartile of systolic or diastolic BP variability. The group with the highest systolic and diastolic BP variability had a 77% higher risk of ESKD than did those in the lowest three quartiles of both systolic and diastolic BP variability. These associations were present in younger individuals without comorbidities.ConclusionsAmong individuals with type 2 diabetes, increased BP variability was associated with an increased risk of ESKD. These associations were similarly observed in younger individuals without comorbidities. Maintaining a consistent BP seems to be important to prevent progression to ESKD in individuals with type 2 diabetes.

Disclosure: C. won-kyoung: None. B. Eunha: None. S. Sim: None. S. Park: None. S. Kim: None. S. Kim: None. M. Ahn: None. S. Kim: None. K. Cho: None. K. Han: None. M. Jung: None. B. Suh: None.OBJECTIVE To explore the incidence of emergency hospitalization among young-onset diabetes using a nationwide registry database. RESEARCH DESIGN AND METHODS Based on the Korean National Health Insurance Service-National Sample Cohort database from 2006 to 2019, data were collected for patients aged ≤30 years with type 1 (T1D) and type 2 diabetes (T2D). The risks of emergency hospitalization were compared with those in the general population. Results: The study consisted of 512,756 participants. T1D and T2D were detected in 428 and 1,298 participants, respectively. After adjusting for sex, age and family income, the hazard ratios (HRs) of any emergency hospitalization were 4.70 (95% confidence interval [CI], 4.07–5.44) and 3.43 (95% CI, 3.07–3.83) for T1D and T2D, respectively. The HRs of emergency hospitalization due to endocrine problems were 439.53 (95% CI, 341.32–566.00) and 57.06 (95% CI, 36.97–88.06) for T1D and T2D, respectively. The HRs of emergency hospitalization due to cardiovascular problems were 3.67 (95% CI, 1.38–9.80) and 6.02 (95% CI, 3.86–9.38) for T1D and T2D, respectively. The HRs of emergency hospitalization due to infective disorders were 3.48 (95% CI, 2.06–5.87) and 4.72 (95% CI, 3.41–6.53) for T1D and T2D, respectively. The HRs of emergency hospitalization due to cancer were 2.57 (95% CI, 0.36–18.26) and 5.57 (95% CI, 2.63–11.81) for T1D and T2D, respectively. Conclusions: In South Korea, patients with young-onset diabetes are at high risk of emergencyhospitalization for various reasons.Presentation: Saturday, July 12, 2025

Disclosure: K. Kim: None. M. Yu: None. Y. Hwang: None. Y. Rhee: None.Multiple Endocrine Neoplasia Type 1-associated Primary Hyperparathyroidism (MEN1-PHPT) is a rare but significant endocrine disorder with high recurrence rates and increased systemic complications. Despite its distinct pathophysiology from sporadic PHPT, large-scale studies on MEN1-PHPT are limited. This study evaluates clinical patterns and complication risks in MEN1-PHPT using nationwide cohort data from the Korean National Health Insurance Service (2002–2020). MEN1-PHPT cases were identified using two operational definitions based on ICD-10 codes and procedures. Definition 1 included patients with at least one D44.8 diagnosis, excluding medullary thyroid carcinoma. Definition 2 included patients meeting at least two criteria: management for primary hyperparathyroidism, pituitary adenomas, or neuroendocrine tumors. A total of 241 MEN1-PHPT patients were matched 1:10 by age, sex, and index year with controls (n = 2,410). Clinical characteristics, comorbidities, and treatment patterns, including parathyroidectomy trends, were analyzed. Adjusted odds ratios (ORs) assessed complication risks. The mean PHPT diagnosis age was 43.6 years (SD 14.2), with 62.2% females, matching control demographics. MEN1-PHPT patients had a higher Charlson Comorbidity Index (2.42 vs. 0.53, p < 0.001) and greater prevalence of diabetes (24.5% vs. 5.1%), hypertension (39.8% vs. 16.2%), dyslipidemia (19.1% vs. 10.9%), osteoporosis (11.2% vs. 0.6%), cardiovascular disease (10.4% vs. 3.6%), and cancer (30.7% vs. 1.3%). Parathyroidectomy (PTX) rates increased over time, with multi-gland surgeries surpassing single-gland procedures by 2016. Repeat surgeries rose, reflecting MEN1-PHPT's recurrent nature. Complication risks were significantly higher in MEN1-PHPT patients. Renal complications had an OR of 11.03 (95% CI: 7.59–16.03), with elevated risks for kidney stones (OR 9.71) and ESRD (OR 12.27). Skeletal complications included non-vertebral fractures (OR 2.17, p = 0.004) and osteoporotic fractures (OR 1.76, p = 0.021). Cardiovascular risks were markedly elevated (OR 32.75, p < 0.001), with cerebrovascular disease showing the highest risk (OR 54.80, p < 0.001). Atrial fibrillation was also significant (OR 2.45, p = 0.010), while myocardial infarction and heart failure risks were elevated but not statistically significant. In summary, MEN1-PHPT patients have a significantly higher burden of comorbidities and complications, requiring more extensive and recurrent surgeries. The trend toward multi-gland and repeat surgeries reflects the disease's complexity. These findings emphasize the need for tailored treatments and long-term monitoring to mitigate complications and improve outcomes.Presentation: Saturday, July 12, 2025