Population-based Study In Korea Research Articles

Long-term toxicities after allogeneic hematopoietic stem cell transplantation with or without total body irradiation: a population-based study in Korea.

To compare long-term toxicity incidences, including secondary cancer (SC) with or without total body irradiation (TBI), in Asian patients receiving allogeneic hematopoietic stem cell transplantation (HSCT) using a nationwide database. We identified 4,554 patients receiving HSCT for leukemic disease from 2009 to 2016 using the healthcare bigdata system of Korea. Incidence rate ratios (IRRs) for SC, cataracts, hypothyroidism, chronic kidney disease (CKD), myocardial infarction, or strokes were compared, and standardized incidence ratios (SIR) of SC was also estimated. TBI was conducted on 1,409 patients (30.9%). No overall survival differences based on TBI were observed. With a median follow-up duration of 58.2 months, 143 patients were diagnosed with subsequent SC (3.4%). Incidence rates per 1,000 person-year were 6.56 (95% confidence interval [CI], 4.8-8.8) and 7.23 (95% CI, 5.9-8.8) in the TBI and no-TBI groups, respectively (p = 0.594). Also, the SIR (95% CI) was not significantly increased by TBI (1.32 [0.86-1.94] vs. 1.39 [1.08-1.77] in the no-TBI group). In the young age group (0-19 years), SIRs were increased in both groups regardless of TBI (8.60 vs. 11.96). The IRRs of cataracts (1.60; 95% CI, 1.3-2.0), CKD (1.85; 95% CI, 1.3-2.6), and hypothyroidism (1.50; 95% CI, 1.1-2.1) were significantly increased after TBI. However, there were no significant differences in the occurrence of myocardial infarction and stroke according to TBI. Our results suggest that modern TBI may not additionally increase the risk of SC after allogeneic HSCT, although increased risks of other diseases were noted. Physicians should carefully consider individualized risks and benefits of TBI, with a particular focus by age group.

Is arthritis an associated risk factor for trigger finger occurrence after carpal tunnel release? A nationwide, population-based study in Korea.

We hypothesized that increased friction between the flexor tendon and surrounding structures due to hand arthritis is an important risk factor for trigger finger (TF) after carpal tunnel release (CTR). Therefore, we compared TF development according to the presence or absence of arthritis in carpal tunnel syndrome (CTS) patients treated with CTR. This retrospective study was based on data collected from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) in the Republic of Korea between January 1, 2002, and December 31, 2015. Patients diagnosed with TF between one month and one year after the CTR date or with a history of surgery were included in the study. During subsequent follow-up, the patients were divided into subgroups of those (1) with TF and (2) without TF. Sex, age, arthritis, and TF-related comorbidities were compared between the subgroups. The subgroup with TF had a higher proportion of women (9.43% vs 90.57%), the highest age range between 50 and 59 years, more cases of arthritis (32.55% vs 16.79%), and a higher proportion of patients with hypothyroidism (10.85% vs 4.60%) than the group without TF. The association between arthritis and TF after CTR was examined using a multivariate logistic regression model, showing arthritis to be a significant risk factor for TF after CTR (odds ratio, 1.35; P = 0.049). We identified arthritis as an important risk factor for the development of TF after CTR.

Association between cardiac arrhythmia before pregnancy and gestational diabetes: a nationwide population-based study in Korea.

Given the higher prevalence of cardiac arrhythmias in individuals with diabetes, we investigated the relationship between cardiac arrhythmias and the incidence of gestational diabetes (GDM). This retrospective cohort study utilized data from the Korean Health Insurance Service database, encompassing 1,113,729 women who gave birth between January 2007 and December 2015. After excluding those who did not undergo National Health Screening tests within 1 year prior to pregnancy, those with multifetal pregnancies, and those diagnosed with diabetes, we analyzed 365,880 singleton pregnancies without a history of diabetes. Of these, 3,253 (0.9%) had cardiac arrhythmias, including premature extra beats, supraventricular tachyarrhythmias, and/or atrial flutter/fibrillation. GDM occurred in 31,938 (8.7%) subjects during pregnancy, and was more prevalent in women with cardiac arrhythmia than in those without (14.9% vs. 8.7%, p<0.001). In the multivariate analysis, the association between cardiac arrhythmia and GDM remained statistically significant (adjusted odds ratio, 1.78; 95% CI, 1.615-1.970; p<0.001). Subgroup analysis revealed that the risk of GDM was consistently statistically significant in subjects with cardiac arrhythmia, regardless of age, body mass index, and the presence or absence of chronic hypertension. Therefore, cardiac arrhythmias before and during pregnancy appear to be associated with an increased risk of developing GDM.

Association between cardiac arrhythmia before pregnancy and gestational diabetes: a nationwide population-based study in Korea

Abstract Background Premature extra betas and supraventricular tachyarrhythmias are prevalent in the gestational period. Gestational diabetes mellitus (GDM) complicated a significant proportion of pregnancies worldwide. Purpose Given the high prevalence of cardiac arrhythmia (CA) among patients with diabetes, we aimed to investigate the association of CA with GDM. Methods This is a nationwide cohort study using the Korean Health Insurance database. We identified 1,113,729 women who gave birth between 2007 and 2015. After excluding subjects who did not undergo the national health screening test within a year before pregnancy, multi-pregnancy, and those with fasting blood glucose ≥126 mg/mL and/or diagnosed with diabetes before pregnancy CA was defined as atrial and ventricular premature beats, paroxysmal tachycardia, and atrial fibrillation. The primary outcome was the incidence of GDM. Subgroup analysis stratified by age and body mass index at pregnancy onset, and a history of hypertension before pregnancy were conducted. Results A total of 365,880 women were included in the final analysis. Of them, 3,253 (0.9%) had a diagnosis of CA. Subjects with CA were older at pregnancy onset (mean age 33.3±4.1 vs. 33.0±3.9 years, P&amp;lt;0.001), and had a higher proportion of hypertension (5.2% vs. 1.0%, P &amp;lt;0.001) than in subjects without CA. GDM was detected in 31,938 (8.7%) subjects and more commonly occurred in subjects with CA than those without (14.9% vs. 8.7%, P&amp;lt;0.001). After adjusting for confounding factors, the incidence of GMD was statistically significantly higher in those with CA (adjusted OR 1.78, 95% CI 1.615–1.970, P&amp;lt;0.001). Moreover, the relationship between CA with GDM was statistically significant regardless of age and body mass index (Figure 1). Meanwhile, despite a higher incidence of GDM, the association between CA and GDM was insignificant in subjects with a history of hypertension. Conclusion The risk of gestational diabetes was higher in subjects diagnosed with CA before or during pregnancy compared with those without CA.

The Risk of Venous Thrombosis for Erythropoiesis Stimulating Agents and Blood Transfusions in Cancer Patients: A Nationwide Population-Based Study in Korea

Introduction: Several previous studies have indicated that both erythropoiesis-stimulating agents (ESAs) and blood transfusions elevate the risk of venous thrombosis in cancer patients. Nevertheless, there has been inconsistency in the evidence regarding whether ESAs or blood transfusions are more closely linked to thrombotic complications. To address this, nationwide population data was analyzed to explore the association between the use of ESAs, blood transfusions, and the risk of venous thrombosis in cancer patients. Methods: This study utilized a case-crossover design and analyzed the National Health Insurance Database of Korea. A total of 710,910 patients diagnosed cancer (ICD-10 code: C00.x-C26.x, C30.x-C34.x, C37.x-C41.x, C45.x-C58.x, C60.x-C76.x, C81.x-C85.x, C88.3, C88.7, C88.9, C90.0, C90.1, C91.x-C93.x, C94.0-C94.3, C94.5, C94.7, C95.x, C96.x) between January 1, 2011, and December 31, 2020 were included. Of these, 57,256 (8.03%) identified with venous thrombosis (ICD-10 code: I80.x). The hazard period, starting from the week of thrombosis and going back 12 weeks, was compared to an earlier 12-week control period separated by a 24-week gap. Secondary analyses were conducted with different durations for the hazard/control periods (8 and 4 weeks) to assess the robustness of the results. Patients served as their own controls, and time-dependent covariates such as granulocyte colony-stimulating factor and chemotherapy were evaluated for their association with thrombotic risk. Patients were categorized based on occurrences of inpatient hospitalization, red blood cell transfusion, platelet transfusion, central venous catheter placement, and major surgery during hazard and control periods, and these variables were compared using χ2 tests. Finally, conditional logistical regression was employed to compare the odds of exposure to ESAs, blood transfusions, and other thrombosis risk factors during the hazard period to the exposure odds during the control period. Results: There were similar rates of ESA use during the hazard period and the control period (0.88% vs. 0.28%; P = 0.477). However, red blood cell transfusions (6.85% vs. 1.79%; P &amp;lt;0.001), platelet transfusions (1.92% vs. 0.48%; P = 0.003), insertion of a central venous catheter (3.34% vs. 0.74%; P &amp;lt;0.001), hospitalizations (11.79% vs. 2.77%; P &amp;lt;0.001), and major surgery (5.70% vs. 2.00%; P &amp;lt;0.001) differed significantly between the two exposure periods. All of these factors were more frequent during the hazard period compared to the control period. In the crude conditional logistical regression model, the odds ratio (OR) for ESA use was significantly increased (OR = 3.14; 95% CI: 2.63, 7.75). However, after controlling for other covariates including red blood cell transfusions, platelet transfusions, central venous catheter insertion, hospitalization, and major surgery in an adjusted model, ESA use was found to be non-significant (OR = 1.12; 95% CI: 0.93, 1.36). In contrast to ESA use, red blood cell transfusion was associated with an increased risk of thrombosis in both the crude model (OR = 3.83; 95% CI: 3.58, 4.11) and the adjusted model (OR = 1.44; 95% CI: 1.32, 1.58). This study also investigated whether varying the lengths of the hazard and control periods (8 and 4 weeks) would affect the association between ESA use, red blood cell transfusions, and thrombotic events. The results showed that the association remained consistent regardless of the duration of the periods. Overall, these findings suggest that while there was an increased risk of thrombosis associated with red blood cell transfusions, the use of ESAs did not show a significant association with thrombotic events after adjusting for other relevant factors. Conclusions: This study revealed a stronger association between red blood cell transfusions and thrombotic complications in cancer patients. These findings suggest that red blood cell transfusions may have a higher thrombotic risk compared to ESAs in this particular patient population. Furthermore, the results indicate that the use of ESAs in cancer patients might not increase the risk of thrombotic complications depending on the exposure duration. Further studies are needed to assess the impact of ESAs and blood transfusions on thrombotic risk in different populations.

332MO Long-term toxicities after allogeneic HSCT with or without total body irradiation: A population-based study in Korea

332MO Long-term toxicities after allogeneic HSCT with or without total body irradiation: A population-based study in Korea

Increased risk of venous and arterial thromboembolism in patients with colorectal cancer receiving cetuximab-based combination chemotherapy: A population-based study in Korea

IntroductionLimited data exist on the risk of venous and arterial thromboembolisms (VTE and ATE) in patients receiving cetuximab plus chemotherapy. We aimed to determine the thromboembolic risk of patients with recurrent/metastatic colorectal cancer (CRC) treated with cetuximab plus chemotherapy compared to chemotherapy alone. MethodsThis population-based study used nationwide claims data from the Health Insurance Review and Assessment Service of South Korea from 2013 to 2020. Patients with recurrent/metastatic CRC treated with first-line oxaliplatin- or irinotecan-based doublets with or without cetuximab and no secondary prevention for VTE and ATE were included. Primary outcomes were the occurrence of any thromboembolic events, VTE, and ATE, which were determined using the cumulative incidence method incorporating death as a competing event. ResultsWe identified 19,723 patients (cetuximab plus chemotherapy, N = 7630; chemotherapy alone, N = 12,093). The cumulative incidence of any thromboembolic events in patients with cetuximab plus chemotherapy was significantly higher than in those receiving chemotherapy alone (6-month, 5.62 % vs. 3.58 %, P < 0.0001). The rates of VTE (6-month, 5.11 % vs. 3.28 %, P < 0.0001) and ATE (6-month, 0.53 % vs. 0.32 %, P = 0.0218) were also higher in patients receiving cetuximab plus chemotherapy. In multivariable analysis, cetuximab plus chemotherapy was independently associated with developing any thromboembolic events (hazard ratio [HR], 1.63; 95 % confidence interval [CI], 1.42–1.87), VTE (HR, 1.62; 95 % CI, 1.40–1.87), and ATE (HR, 1.77; 95 % CI, 1.16–2.71). ConclusionsCetuximab with irinotecan- or oxaliplatin-based doublet chemotherapy was associated with an increased risk of any thromboembolic events, VTE, and ATE; further studies are warranted to examine the underlying mechanisms.

Serum levels of perfluoroalkyl substances (PFAS) and exposure determinants in adolescents: A population-based study in Korea

Serum levels of perfluoroalkyl substances (PFAS) and exposure determinants in adolescents: A population-based study in Korea

JAAD Game Changer: “Vitiligo and overt thyroid diseases: A nationwide population-based study in Korea”

JAAD Game Changer: “Vitiligo and overt thyroid diseases: A nationwide population-based study in Korea”

Bidirectional associations between periodontal disease and systemic diseases: a nationwide population-based study in Korea

To evaluate the associations of periodontal disease (PD) with systemic diseases, including diabetes mellitus (DM) and cardiovascular disease (CVD), as well as the reciprocal association. The CVD included the cases of coronary heart disease and heart failure. A prospective study was conducted from 2007 to 2019 using linked data from three databases in Korea. Three separate study groups were formed to individually determine the risks of PD (n = 10,533), DM (n = 14,523) and CVD (n = 14,315). All diseases were confirmed based on physicians’ diagnoses using medical records and self-reports. Cox proportional hazard regression was applied with 95% confidence intervals (CIs) to obtain hazard ratios (HRs). PD was significantly associated with an elevated risk of DM (HR [95% CI]: 1.22 [1.07–1.39]) after full adjustment for age, sex, lifestyle factors, body mass index, dental behaviour and CVD. PD was also found to increase the risk of CVD (1.27 [1.03–1.57]), whereas CVD increased the risk of PD (1.20 [1.09–1.32]) after full adjustment for other covariates including DM. This study found a bidirectional association between PD and CVD, as well as a positive association of PD with DM.

Gender Inequalities in Mental Health During the COVID-19 Pandemic: A Population-based Study in Korea.

This study explored the effect of the coronavirus disease 2019 (COVID-19) pandemic on psychosocial stress in prime working-age individuals in Korea, focusing on gender inequalities. We hypothesized that the impact of COVID-19 on mental health would differ by age and gender, with younger women potentially demonstrating heightened vulnerability relative to men. The study involved data from the Korea Community Health Survey and included 319 592 adults aged 30 years to 49 years. We employed log-binomial regression analysis, controlling for variables including age, education, employment status, marital status, and the presence of children. The study period included 3 phases: the period prior to the COVID-19 outbreak (pre-COVID-19), the early pandemic, and the period following the introduction of vaccinations (post-vaccination). The findings indicated that women were at a heightened risk of psychosocial stress during the early pandemic (relative risk [RR], 1.01; 95% confidence interval [CI], 0.98 to 1.05) and post-vaccination period (RR, 1.07; 95% CI, 1.04 to 1.10) compared to men. This pattern was prominent in urban women aged 30-34 years (pre-COVID-19: RR, 1.06; 95% CI, 1.02 to 1.10; early pandemic: RR, 1.16; 95% CI, 1.08 to 1.25; post-vaccination period, RR, 1.22; 95% CI, 1.14 to 1.31). The COVID-19 pandemic has exerted unequal impacts on psychosocial stress among prime working-age individuals in Korea, with women, particularly those in urban areas, experiencing a heightened risk. The findings highlight the importance of addressing gender-specific needs and implementing appropriate interventions to mitigate the psychosocial consequences of the pandemic.

All-Cause and Cause-Specific Mortality among Patients with Vitiligo: A Nationwide Population-Based Study in Korea

Vitiligo is a common autoimmune skin disorder; however, there is limited information about risks of mortality among patients with vitiligo. Therefore, we aimed to investigate the mortality in patients with vitiligo. A population-based cohort study was conducted using the data linkage of the National Health Insurance Service database and the National Death Registry. Patients with incident vitiligo were matched with sociodemographic factors-matched controls without vitiligo in a 1:5 ratio. All-cause and cause-specific mortalities were compared between patients with vitiligo and controls. In total, 107,424 patients with incident vitiligo and 537,120 matched controls were included. The mortality rates were 34.8 and 45.3 per 10,000 person-years in patients and controls, respectively. Patients with vitiligo showed a significantly lower risk of mortality (adjusted hazard ratio= 0.75, 95% confidence interval= 0.72-0.78). The cause-specific mortality from infectious diseases, oncologic diseases, hematologic diseases, endocrine diseases, neurologic diseases, cardiovascular diseases, respiratory diseases, and renal/urogenital disease was significantly lower in patients with vitiligo. Patients with vitiligo were associated with a lower risk of mortality, suggesting that vitiligo-associated autoimmunity might contribute to reduced morbidity and mortality.

Rapid weight gain in early life is associated with central precocious puberty in girls, not in boys - a nationwide population-based study in Korea.

This study aimed to investigate the effect of rapid weight gain (RWG) on the incidence of central precocious puberty (CPP) using nationwide population-based data. A total of 253,967 children (101,841 boys and 152,126 girls) who underwent regular health consultations under the National Health Insurance Service from 2007 to 2010 were followed up until the age of 10 years for boys and 9 years for girls. We calculated differences in the weight Z-scores from 4-6 months to 9-12 months (infancy) and from 9-12 months to 18-24 months or 30-36 months (toddlerhood) using the lambda-mu-sigma method. The population was subdivided into four groups: RWGinf/tod (infancy > + 0.67 standard deviation score [SDS], toddlerhood > 0 SDS), RWGinf (infancy > + 0.67 SDS, toddlerhood < 0 SDS), RWGtod (toddlerhood > + 0.67 SDS), and control (no RWG). The diagnosis of CPP was based on the diagnostic codes of the International Classification of Diseases 10th revision and the prescription of gonadotropin-releasing hormone agonists. The cumulative risk of CPP based on age was analyzed using Kaplan-Meier survival curves, and the association between the RWG groups and CPP was assessed using multivariate logistic regression analysis. CPP was diagnosed in 268 boys and 9,225 girls. For the girls, the CPP-free probability was the highest in the control group, followed by the RWGtod, RWGinf, and RWGinf/tod groups (log-rank p < 0.001). However, the incidence of CPP did not vary significantly for the boys. Compared to the control group, the other groups had a higher risk of CPP in girls (RWGinf/tod: adjusted odds ratio [aOR] 1.35, 95%, confidence interval [95% CI] 1.13-1.62; RWGinf: aOR 1.25, 95% CI 1.13-1.38; and RWGtod: aOR 1.18, 95% CI 1.09-1.28). This nationwide population-based study demonstrated that any RWG from birth to 3 years of age contributed to an increased risk of CPP in girls but not in boys. Girls who experienced RWG during both infancy and toddlerhood had the highest risk of developing CPP. These findings suggest that early detection and appropriate management of excessive weight gain in early life may be important for preventing CPP in girls.

Trends in treatment patterns and survival outcomes in pancreatic cancer: A nationwide population-based study in Korea

BackgroundThe treatment of pancreatic cancer has evolved; however, real-world data on treatment trends remain scarce. This study investigated treatment patterns for pancreatic cancer and patient survival using a nationwide population-based study in Korea. MethodsUsing the National Health Insurance database, data from 78,920 patients diagnosed with pancreatic cancer in Korea between 2006 and 2019 were extracted. Treatment patterns and survival by age group and year of diagnosis were examined. ResultsPrimary treatment was delivered as follows: 16,562 patients (21.0%) underwent surgery, 20,998 patients (26.6%) received chemotherapy, 1332 patients (1.7%) received chemoradiotherapy, and 40,040 patients (50.7%) received supportive care only. The proportion of patients undergoing surgery or chemotherapy increased gradually in all age groups over time. The commonly used anti-cancer drugs have changed from gemcitabine±erlotinib to gemcitabine+nab-paclitaxel and FOLFIRINOX. Survival improved mainly in patients who underwent surgery or chemotherapy. Median overall survival for all patients improved from 5.5 months in 2006–2008 to 9.8 months in 2018–2019, with greater improvement observed in younger age groups: 8.8–18.8 months, age ≤59 years, 6.8–14.6 months, age 60–69 years, 4.2–8.3 months, age 70–79 years and 2.4–3.4 months, age ≥80 years (all p < 0.0001). ConclusionsAn increase in the rates of surgery and chemotherapy for pancreatic cancer was observed. Survival rates for pancreatic cancer have generally improved over the past decade and are greater in patients undergoing surgery or chemotherapy and in younger age groups.

Two-Year Changes in Diabetic Kidney Disease Phenotype and the Risk of Heart Failure: A Nationwide Population-Based Study in Korea.

Diabetic kidney disease (DKD) is a risk factor for hospitalization for heart failure (HHF). DKD could be classified into four phenotypes by estimated glomerular filtration rate (eGFR, normal vs. low) and proteinuria (PU, negative vs. positive). Also, the phenotype often changes dynamically. This study examined HHF risk according to the DKD phenotype changes across 2-year assessments. The study included 1,343,116 patients with type 2 diabetes mellitus (T2DM) from the Korean National Health Insurance Service database after excluding a very high-risk phenotype (eGFR <30 mL/min/1.73 m2) at baseline, who underwent two cycles of medical checkups between 2009 and 2014. From the baseline and 2-year eGFR and PU results, participants were divided into 10 DKD phenotypic change categories. During an average of 6.5 years of follow-up, 7,874 subjects developed HHF. The cumulative incidence of HHF from index date was highest in the eGFRlowPU- phenotype, followed by eGFRnorPU+ and eGFRnorPU-. Changes in DKD phenotype differently affect HHF risk. When the persistent eGFRnorPU- category was the reference, hazard ratios for HHF were 3.10 (95% confidence interval [CI], 2.73 to 3.52) in persistent eGFRnorPU+ and 1.86 (95% CI, 1.73 to 1.99) in persistent eGFRlowPU-. Among altered phenotypes, the category converted to eGFRlowPU+ showed the highest risk. In the normal eGFR category at the second examination, those who converted from PU- to PU+ showed a higher risk of HHF than those who converted from PU+ to PU-. Changes in DKD phenotype, particularly with the presence of PU, are more likely to reflect the risk of HHF, compared with DKD phenotype based on a single time point in patients with T2DM.

Metformin and Cervical Cancer Risk in Patients with Newly Diagnosed Type 2 Diabetes: A Population-Based Study in Korea.

Metformin and Cervical Cancer Risk in Patients with Newly Diagnosed Type 2 Diabetes: A Population-Based Study in Korea.

Prevalence and incidence of vitiligo and associated comorbidities: a nationwide population-based study in Korea.

The prevalence of vitiligo shows regional variance. Recently, an association between vitiligo and extracutaneous conditions including other autoimmune, metabolic and dermatological disorders has been suggested. Despite its increasing incidence, the epidemiological trends and comorbidities in people with vitiligo have rarely been quantified in Asia. To determine the prevalence and incidence of vitiligo and the disorders associated with vitiligo using the National Health Insurance Service database. We included all patients with vitiligo, classified by the International Classification of Disease, 10th revision (ICD-10) code of L80, with ≥ 3 documented visits from 2003 to 2019. The incidence and prevalence of vitiligo were estimated for the study period. Age-, sex-, insurance type- and income level-matched controls (ratio 1 : 5) were selected to compare comorbidities. The odds ratios between comorbidities and vitiligo were calculated through conditional logistic regression. The incidence and annual prevalence of vitiligo in Korea increased from 2003 to 2019, with incidence peaking in summer. Age-specific incidence showed a bimodal distribution, with the steepest increase in the group aged < 20 years. Many comorbidities, including alopecia areata, psoriasis, rheumatoid arthritis, systemic lupus erythematosus, Crohn disease, ulcerative colitis, Sjögren syndrome, diabetes mellitus, dyslipidaemia, chronic hepatitis, anxiety disorder and mood disorder showed higher odds ratios in patients with vitiligo than controls. The incidence and prevalence of vitiligo are increasing, particularly among younger patients in Korea. In addition, various comorbidities are associated with vitiligo, therefore, if patients with vitiligo present with extracutaneous symptoms, physicians should consider the possibility of other comorbid diseases.

Metformin and Cervical Cancer Risk in Patients with Newly Diagnosed Type 2 Diabetes: A Population-Based Study in Korea.

Cervical cancer is a prevalent malignancy that is a major health problem for women worldwide. The cancer-preventive properties of metformin are well-known, but insufficient data have been reported regarding its relationship to cervical cancer. Therefore, in a nationwide population-based study, we investigated the association between metformin use and cervical cancer incidence in patients with newly diagnosed type 2 diabetes. This retrospective cohort study used the Korean National Health Insurance claims database. Individuals newly diagnosed with type 2 diabetes between January 2005 and December 2009 were included. The occurrence of cervical cancer was explored by matching for age, economic status, region of residence, and use of anti-diabetic medication. In total, 66,013 metformin users and 64,756 non-users were analyzed. Cervical cancer occurred in 219 metformin users (0.33%) and 274 metformin non-users (0.42%) (hazard ratio [HR], 0.783; 95% confidence interval [CI], 0.655 to 0.036; P=0.007). Moreover, cervical cancer risk was considerably reduced in those treated with a high dose (>1,200,000 mg) or for an extended period (≥2,000 days) compared to non-users (HR, 0.151; 95% CI, 0.093 to 0.243; P<0.001; and HR, 0.141; 95% CI, 0.077 to 0.258; P<0.001). The incidence was also significantly lower in metformin users among those over 50 years old (HR, 0.791; 95% CI, 0.650 to 0.961; P<0.001). Metformin use in patients with newly diagnosed diabetes was associated with a lower risk of cervical cancer in Korea. Furthermore, a significant association was found between the use of metformin and cervical cancer in a dose- and duration-dependent manner and among those over 50 years old.

1173. Increased risk of dementia in patients after Scrub typhus: a nationwide, population-based study in Korea

Abstract Background Scrub typhus causes systemic vasculitis and can lead to complications ranging from pneumonia and acute renal injury to meningitis or encephalitis. In South Korea, it occurs not only in rural areas but also in urban areas, and especially high in older people. We hypothesized that patients with scrub typhus are predisposed to increased risks for developing dementia. Methods We performed a population-based cohort study, in which persons aged between 60∼89 years, used the Health Insurance Review and Assessment database of South Korea between 2009 and 2018. The case definition of scrub typhus was based on the ICD-10 diagnostic code and prescription of doxycycline more than three days. Dementia was defined as patients with the code in expending benefit coverage or patients with the ICD-10 codes, examination codes and drug codes. The control group was selected as stratifying by age and gender at a ratio of 1:5 to the number of the case group in study population. Results During the observational periods, Of 76,073 patients had diagnosed with scrub typhus, 5,026 excluded due to diagnosed with scrub typhus during window period, with dementia or died before index date, 71,047 patients were included as case group. 355,235 patients were included as controls. During a mean follow-up of 5.6±2.9 years, 14,089 (19.8%) patients with previous scrub typhus and 61,807 (15.2%) controls had been developed dementia. Scrub typhus was significantly associated with dementia (adjusted hazard ratio [aHR], 1.12; 95% confidential interval [CI], 1.10-1.15, P&amp;lt; 0.001). Of dementia classification, the risk of Alzheimer dementia was significantly higher in the case group (17.8% vs 15.2%; aHR, 1.15; 95%CI, 1.13-1.18, p&amp;lt; 0.001), however, there was no significant difference in the risk of vascular dementia (2.1% vs 2.2%; aHR, 0.98; 95%CI, 0.83-1.16, p=0.82). Cumulative incidence of dementia during the follow-up period by the history of scrub typhus It shows in both groups dementia incidence increased over time and the case group had higher incident dementia compared with control group. Conclusion History of scrub typhus infection in elderly was associated with increased risk for dementia, especially Alzheimer’s dementia. Our results suggest that prevent measures of dementia could be improved by preventing and treating scrub typhus. Disclosures All Authors: No reported disclosures.

2149. Risk of dental abnormalities after tetracycline exposure in children: A retrospective, population-based study in Korea, 2003-2015

Abstract Background Despite its clinical usefulness, the use of tetracycline antibiotics (TCs) in children has historically been limited because of the risk of permanent tooth discoloration and enamel deformity, although age restrictions have varied across countries (e.g., contraindicated under 8 years of age in Taiwan, USA, and Canada, and under 12 years of age in Korea and UK). We explored whether the incidence of dental abnormalities in Korean children with a history of TCs use differed by age. Furthermore, the relative risk compared to the TCs non-exposed group was calculated. Methods From 2002 to 2015, 1 million standard sample subjects data was provided from National Health Insurance Service in Korea. Children younger than 18 years were included and divided into groups A (0-7 years), B (8-12 years), and C (13-17 years). Subjects in 2002 were excluded for wash-out, as were those diagnosed with dental abnormalities within 6 months after TCs prescription. For comparison, 1:4 matching between the TCs exposure and non-exposure groups was performed according to age and gender. Results Among 14,831 individuals included as study subjects (487 (3%) in group A; 1,695 (11%) in group B; and 12,649 (85%) in group C), 201 (1.4%) were diagnosed with dental abnormalities. The 5-year cumulative incidence of dental abnormalities after exposure to TCs in the group A was 4.7%, which was significantly higher than that of the control group C (0.9%; p&amp;lt; 0.0001), but that of group B was 1.3% and not significantly different from that of group C. In the risk analysis of dental abnormalities according to exposure of TCs, there was no significant difference (adjusted RR=1.03, 95%CI=0.71 to 1.50 in group A; adjusted RR=1.13, 95%CI=0.76 to 1.69 in group B; adjusted RR=1.18, 95%CI=0.97 to 1.43 in group C). Fig 1.Cumulative incidence rate and relative risk analysis.A. Cumulative incidence rate of dental abnormalities after TCs exposure by age group (p = &amp;lt;.00001). B. Relative risk analysis by TCs exposure and age group.Abbreviation; TCs: tetracycline and its derivatives. Conclusion Korean children aged 0-7 years who were exposed to TCs had a higher cumulative incidence and relative risk of dental deformities compared to the 13-17-year-old group but not the 8-12-year-old group. No significant increase in dental abnormalities was observed with TCs exposure among pediatric age groups. Disclosures All Authors: No reported disclosures.