National Sample Cohort Database Research Articles

Burden of Herpes Zoster in Individuals With Chronic Conditions in the Republic of Korea: A Nationwide Population-Based Database Study

Abstract Background Chronic conditions (CCs) may increase the risk of herpes zoster (HZ) infection, leading to a greater healthcare burden in these individuals compared to those without CCs. It is therefore clinically important to quantify HZ disease burden in individuals with and without CCs, given the rapidly aging population in the Republic of Korea (ROK). Methods This retrospective cohort study examines the trends in incidence rates (IRs) and incidence rate ratios (IRRs) in individuals aged ≥18 years with CCs, using the National Health Insurance Service National Sample Cohort (NHIS-NSC) database from 2010 to 2019. These patients were stratified by age group, sex, HZ complications, and CCs. The annual average number of HZ patients, IRs, and IRRs were calculated for individuals with and without CCs. Results In total, 729 347 patients with HZ were eligible for the study. HZ IRs were highest in patients with diabetes, followed by chronic obstructive pulmonary disease, chronic kidney disease, asthma, and chronic liver disease, with HZ IRRs following a similar trend. Overall, HZ IRs generally increased with age, typically peaking at 60–64 or 65–69 years, and were similar for females and males. HZ IRs were highest among patients without complications, followed by HZ with other, cutaneous, ocular, and neurologic complications across all CCs. For each of the CCs, HZ IRs were consistently higher than those of the non-CC population regardless of sex. Conclusions The findings of this study reiterate the importance of HZ prevention for healthy aging, especially for CC populations at increased risk of HZ in the ROK.

Cranial Nerve Palsy and Risk of Kidney Cancer: A Nationwide Population-Based Study.

Background and Objective: Understanding whether cranial nerve palsy (CNP) acts as an independent risk factor for kidney cancer could have important implications for patient care, early detection, and potentially the development of preventive strategies for this type of cancer in individuals with CNP. This study aimed to examine the risk of kidney cancer following the onset of ocular motor CNP and assess whether CNP could be considered an independent risk factor for kidney cancer. Materials and Methods: A population-based cohort study was conducted using data from the National Sample Cohort (NSC) database of Korea's National Health Insurance Service which was collected from 2010 to 2017. Follow-up was until kidney cancer development, death, or 31 December 2018. Cox proportional hazard regression analysis was performed to determine hazard ratios (HRs) for kidney cancer according to CNP status. Participants aged 20 years or more diagnosed with CNP from 2010 to 2017 were included. Exclusions comprised individuals with specific pre-existing conditions, inability to match a control group, and missing data, among others. CNP patients were age-sex matched in a 1:5 ratio with control cases. The primary outcome was incidence of kidney cancer during the follow-up period. Results: This study comprised 118,686 participants: 19,781 in the CNP group, and 98,905 in the control group. Compared to the control group, participants with CNP had a higher risk of kidney cancer (adjusted HR in model 4, 1.599 [95% CI, 1.116-2.29]). After a 3-year lag period, the CNP group had a significantly higher risk (adjusted HR in model 4, 1.987 [95% CI, 1.252-3.154]). Conclusions: Ocular motor CNP may be an independent risk factor for kidney cancer, as indicated by a higher incidence of kidney cancer in CNP patients. Further research is needed to elucidate the underlying mechanisms and explore potential preventive measures for kidney cancer in patients with ocular motor CNP.

Proteinuria and risk of ocular motor cranial nerve palsy: a nationwide population-based study

Understanding the association between dipstick-detected proteinuria and oculomotor cranial nerve palsy (CNP) could have significant implications for understanding the mechanism of CNP development and for developing preventive strategies against CNP development in patients with proteinuria. This study aimed to determine the relationship between dipstick-determined proteinuria and ocular motor CNP using National Sample Cohort (NSC) database from Korea’s National Health Insurance Service (NHIS). A nationwide population-based cohort study was conducted using data from the NSC database of Korea’s NHIS. These data were collected from 2009 to 2018. A one-year time lag was established to prevent a situation in which the causal link was inverted. Participants aged 20 years or more who were diagnosed with proteinuria in 2009 were included. Individuals with specific pre-existing CNP, missing data, and those who were newly diagnosed with CNP or who died within one year of being tested were excluded. The study population was classified into six groups according to the degree of proteinuria (negative, trace, or between 1 + and 4 +) based on the urine dipstick test. A Cox proportional hazard regression analysis was performed to determine the linkage between the degree of proteinuria and ocular motor CNP. A total of 5,807 (0.14% of subjects) with ocular motor CNP were assigned to the ocular motor CNP group and 4,047,205 subjects were assigned to the control group. After full adjustment of comorbidities, hazard ratios (HRs) for 1 + , 2 + , 3 + and 4 + proteinuria groups were 1.449 (95% confidence interval [CI] 1.244–1.687), 2.081 (1.707–2.538), 1.96 (1.322–2.904), and 3.011 (1.507–6.014), respectively, for developing ocular motor CNP compared to the proteinuria-negative group. In subgroup analysis, the HR of patients with proteinuria for the development of ocular motor CNP was higher in the younger age group (less than 40 years) (P = 0.0242) and the group with DM (P = 0.04). Our population-based cohort study demonstrated a significant association between proteinuria and the incidence of CNP, suggesting that urine protein level could be a new clinical marker for predicting the development of CNP.

Association between proton pump inhibitors use and risk of asthma in Korea: A prevalent new-user cohort study.

There have been conflicting mechanisms that proton pump inhibitors (PPIs) may promote or prevent asthma development. However, the evidence on the association of PPI use with the risk of asthma and its exposure-response relationship has been limited. We aim to identify the association between the use of PPIs and the incidence of asthma, compared with use of histamine 2 receptor antagonists (H2RAs). A nationwide, prevalent new-user cohort study was conducted using Korea's National Sample Cohort database. Patients were defined as PPI or H2RA users between 2003 and 2019. PPI users matched to H2RA users based on time-conditional propensity score. Cox proportional hazards model was used to estimate adjusted hazard ratios with 95% confidence intervals of incident asthma associated with PPI use by duration of use, cumulative dose, and average dose per duration. Among the 250,041 pairs, PPI users (51.3% male; mean [SD] age, 42.6 [16.5]; mean follow-up, 6.7 years) showed a higher incidence rate of asthma (7.94 events per 1000 person-year) compared to H2RA users (3.70 events per 1000 person-year) with adjusted hazard ratio of 2.15 (95% confidence interval = 2.08-2.21). The risk of asthma was significantly increased across all observed groups of duration of use, cumulative dose, and average dose per duration. This study suggested that PPI use is associated with an increased risk of developing asthma compared to H2RA use.

Trend of incidence rate of age-related diseases: results from the National Health Insurance Service–National Sample Cohort (NHIS-NSC) database in Korea: a cross- sectional study

BackgroundThis study aimed to identify and select age-related diseases (ARDs) in Korea, which is about to have a super-aged society, and to elucidate patterns in their incidence rates.MethodsThe National Health Insurance Service–National Sample Cohort, comprising 1 million health insurance and medical benefit beneficiaries in Korea from 2002 to 2019, was utilized. We selected 14 diseases with high disease burden and prevalence among Koreans from the 92 diseases defined in the Global Burden of Diseases, Injuries, and Risk Factors Study as ARDs. The annual incidence rate represented the number of patients newly diagnosed with an ARD each year from 2006 to 2019, excluding those with a history of ARD diagnosis from 2002 to 2005. The incidence rate by age was categorized into 10-year units based on age as of 2019. The number of patients with ARDs in each age group was used as the numerator, and the incidence rate for each age group was calculated with the age group as the denominator.ResultsRegarding the annual incidence rates of ARDs from 2006 to 2019, chronic obstructive pulmonary disease, congestive heart failure, and ischemic heart disease decreased annually, whereas dyslipidemia, chronic kidney disease, cataracts, hearing loss, and Parkinson's disease showed a significant increase. Hypertension, diabetes, cerebrovascular disease, osteoporosis, osteoarthritis, and age-related macular degeneration initially displayed a gradual decrease in incidence but exhibited a tendency to increase after 2015. Concerning age-specific incidence rates of ARDs, two types of curves emerged. The first type, characterized by an exponential increase with age, was exemplified by congestive heart failure. The second type, marked by an exponential increase peaking between ages 60 and 80, followed by stability or decrease, was observed in 13 ARDs, excluding congestive heart failure. However, hypertension, ischemic heart disease, cerebrovascular disease, chronic obstructive pulmonary disease, and hearing loss in men belonged to the first type.ConclusionsFrom an epidemiological perspective, there are similar characteristics in age-specific ARDs that increase with age, reaching a peak followed by a plateau or decrease in Koreans.

Cancer risks in patients with ankylosing spondylitis and the effects of biologic agents: a population-based study

Abstract Objective The objective of this study was to conduct a population-based analysis of the malignancy risks of patients with AS. Methods A total of 1796 patients with AS and 7184 age- and sex-matched controls (1:4 ratio) were selected from the Korea National Health Insurance Service–National Sample Cohort database. Data of patients diagnosed with AS (code M45) according to the International Classification of Diseases (ICD) 10th edition, between 2002 and 2019, were reviewed. These data were extracted based on the ICD codes assigned to cancer patients. Results Cancer developed in 168/1796 patients (9.3%) after the AS diagnosis. After adjusting for confounders, the cancer risk of patients with AS was not significantly increased compared with that of controls [adjusted hazard ratio (HR): 1.1; 95% CI: 0.93–1.31]. However, the risks for upper gastrointestinal (GI) cancer (adjusted HR: 1.51; 95% CI: 1.07–2.12) and haematologic malignancy (adjusted HR: 2.36; 95% CI: 1.2–4.65) were significantly higher in patients with AS than in controls. There were no significant differences in the risks for other major cancers between patients with AS and controls. Regarding medication for AS, the HR of upper GI cancer was higher in patients with AS compared with controls (adjusted HR: 1.51; 95% CI: 1.00–2.29). Conclusion The overall cancer risk in patients with AS was not significantly different compared with that in the controls. However, while the effect of NSAIDs on upper GI cancer cannot be ruled out, patients with AS exhibited a significant increase in the risk of both upper GI cancer and haematologic malignancy.

Proton Pump Inhibitors and Likelihood of Colorectal Cancer in the Korean Population: Insights from a Nested Case–Control Study Using National Health Insurance Data

The potential connection between proton pump inhibitors (PPIs) and colorectal cancer (CRC) risk remains unclear, with specific ethnic genetic backgrounds playing a role in PPI-induced adverse effects. In this nested case–control study, we investigated the risk of CRC in relation to preceding PPI use and the duration of use using data from the Korean National Health Insurance Service–National Sample Cohort database, including 9374 incident CRC patients and 37,496 controls. To assess the impact of preceding PPI exposure (past vs. current) and use duration (days: <30, 30–90, and ≥90) on incident CRC, we conducted propensity score overlap-weighted multivariate logistic regression analyses, adjusted for confounding factors. Our findings revealed that past and current PPI users had an increased likelihood of developing CRC. Regardless of duration, individuals who used PPIs also had higher odds of developing CRC. Subgroup analyses revealed that CRC occurrence increased independent of history or duration of prior PPI use, consistent across various factors such as age, sex, income level, and residential area. These findings suggest that PPI use, regardless of past or present use and duration of use, may be related to an increased risk of developing CRC in the Korean population.

Treatment Changes and Prognoses in Patients with Incident Drug-Induced Parkinsonism Using a Korean Nationwide Healthcare Claims Database.

This retrospective cohort study assessed treatment changes and prognoses after incident drug-induced parkinsonism (DIP). We used the National Health Insurance Service's National Sample Cohort database in South Korea. We selected patients diagnosed with incident DIP and given prescriptions to take offending drugs (antipsychotics, gastrointestinal (GI) motility drugs, or flunarizine) for a period of time that overlapped with the time of DIP diagnosis during 2004-2013. The proportion of patients experiencing each type of treatment change and prognosis was assessed for 2 years after DIP diagnosis. We identified 272 patients with incident DIP (51.9% of patients were aged ≥ 60 years and 62.5% of them were women). Switching (38.4%) and reinitiation (28.8%) were the most common modifications in GI motility drug users, whereas dose adjustment (39.8%) and switching (23.0%) were common in antipsychotic users. The proportion of persistent users was higher among antipsychotic users (7.1%) than that among GI motility drug users (2.1%). Regarding prognosis, 26.9% of patients experienced DIP recurrence or persistence, the rate being the highest in persistent users and the lowest in patients who discontinued the drug. Among patients with incident DIP diagnoses, the patterns of treatment change and prognosis differed across the types of offending drugs. Over 25% of patients experienced DIP recurrence or persistence, highlighting the need for an effective strategy to prevent DIP.

Comparison of general and regional anesthesia on short-term complications in patients undergoing total knee arthroplasty: A retrospective study using national health insurance service-national sample cohort.

This retrospective study compared the mortality and short-term complications according to the choice of general anesthesia or regional anesthesia in patients who underwent a total knee arthroplasty (TKA). We searched the Korean National Health Insurance Service National Sample Cohort database to analyze data from patients who received a TKA between January 2002 and December 2015. Before comparing the general and the regional anesthesia groups, the bias was reduced by propensity score matching. After matching, the mortality and complications occurring within 30 days after a TKA were compared between the 2 groups. In the database, 6491 primary TKA cases were identified. Nine hundred forty-three patients (14.5%) had a TKA performed under general anesthesia, and 5548 (85.5%) had a TKA performed under regional anesthesia. After propensity score matching, the data of 1886 patients were analyzed, with 943 patients in each group. There was no significant difference in mortality (0.32% vs 0.00%), transfusion rate (84.52% vs 84.73%, P = .8989), and length of hospital stay (50 vs 53, P = .5391) between the general and regional anesthesia groups. Most of the complications were not significantly different, but the major complications, including myocardial infarction (1.70% vs 0.64%, P = .0414) and acute renal failure (0.85% vs 0.11%, P = .0391), were higher in the general anesthesia group than in the regional anesthesia group. Also, admission to the intensive care unit (8.48% vs 2.33%, P < .0001) and total cost (₩8067, 400 vs ₩7487, 940, P = .0002) were higher in the general anesthesia group than in the regional anesthesia group. Our study found that regional anesthesia for TKA is associated with a decrease in major complications, including myocardial infarction and acute renal failure, and medical costs.

Association between WHO First-Step Analgesic Use and Risk of Breast Cancer in Women of Working Age.

We assessed the association between breast cancer and analgesic use in women of a specific working-age group. The Korean National Health Insurance Service-National Sample Cohort database (KNHIS-NSC) data were analyzed. We calculated hazard ratios (HRs) with 95% confidence intervals (CIs) for patients' cancer risk based on whether the women participated in economic activity (PEA or not PEA (NPEA) groups) and analgesic use. Additionally, breast cancer incidence variations by age group, and PEA or NPEAs, health behavior, Charlson Comorbidity Index, and analgesic use were evaluated. The PEA group had a higher cancer risk than the NPEA group (HR = 1.542, 95% CI: 1.345-1.768, p < 0.001). Breast cancer risk was high in the PEA, high income, and no history of exercise groups, but significantly reduced in the regular-use-of-analgesics group. Notably, the working age group of 40~49 years, within the PEA group, had the highest HR of breast cancer development (HR = 1.700, 95% CI = 1.361-2.124, p < 0.001); whereas regular analgesic use in those aged 25~39 years decreased breast cancer risk (HR = 0.611, 95% CI = 0.427-0.875, p < 0.05). In conclusion, our results suggest that individuals at a high-risk of comorbidity may benefit from regular use of analgesics, which may prove to be a useful strategy for breast cancer prevention in the Young-aged group.

Impact of Clinical Association Between Gout and Dementia: A Nationwide Population-Based Cohort Study in Korea.

Hyperuricemia might have neuroprotective or neurodegenerative effects on dementia via oxidative stress or inflammatory response regulation. Few studies have explored the association of hyperuricemia or gout with dementia. This retrospective cohort study aimed to investigate the association between gout and dementia in Korea. Altogether, 5,052 gout patients and 25,260 age- and sex-matched controls were selected from the National Health Insurance Service (NHIS)-National Sample Cohort database. The incidence and risk of dementia were evaluated by reviewing the NHIS record. We also performed a subgroup analysis according to age group (age <65 or ≥65 years) using the standard age of 65 years for elderly and nonelderly groups and sex. During follow-up, 81 and 558 participants in the gout and control cohorts developed dementia, respectively. The mean follow-up duration was 4.38 years in gout patients and 4.94 years in controls. Gout patients had a hazard ratio (HR) of 0.79 for overall dementia (95% confidence interval [95% CI] 0.62-1.00) and significantly lower Alzheimer's disease risk (HR 0.73 [95% CI 0.54-0.98]) after adjusting for age, sex, household income, and comorbidities. In subgroup analysis stratified by age and sex, the inverse association between gout and the risk of overall dementia (HR 0.71 [95% CI 0.52-0.97]) and Alzheimer's disease (HR 0.67 [95% CI 0.46-0.97]) were observed in the elderly male group. On the other hand, age- and sex-adjusted analysis showed that the HR for vascular dementia of gout patients was 2.31 (95% CI 1.02-5.25) in the nonelderly male group. Gout decreased the risk of incident Alzheimer's disease-type dementia, especially in elderly patients. The association between gout and dementia risk may differ according to age and disease duration.

The risk of osteoporotic fractures after gastrectomy: Findings from the Korean national sample cohort database (2002-2019).

This study used a national sample cohort database to investigate the risk of osteoporotic fractures after gastrectomy is performed for gastric cancer. We used data from the Korea National Health Insurance Service-National Sample Cohort between 2002 and 2019. After performing 1:3 propensity score matching, 28,328 individuals were analysed in the final study (7, 082 cases; 21, 246 controls). Gastrectomy data were extracted from the coded claims data, and osteoporotic fractures were defined as the occurrence of fractures in any of the vertebrae, distal radius, humerus, or hip, according to the 10th version of the International Classification of Diseases. A Cox proportional hazards regression model was generated to investigate the association between gastrectomy and risk of osteoporotic fractures. Patients with gastric cancer who underwent a gastrectomy had a higher risk of osteoporotic fractures as compared to the general population (men, hazard ratio [HR]: 1.13, 95% confidence interval [CI]: 1.00-1.27; women, HR: 1.18, 95% CI: 1.06-1.30). A significantly higher risk of osteoporotic fractures was observed with surgical resection than with endoscopic resection (men, surgical, HR: 1.28, 95% CI: 1.08-1.52, endoscopic, HR: 1.04, 95% CI: 0.90-1.21; women, surgical, HR: 1.34, 95% CI: 1.11-1.62, endoscopic, HR: 1.13, 95% CI: 1.01-1.27). In men, the risk of hip fracture was the highest among the four fracture sites (HR: 1.18, 95% CI:0.89-1.56), while in women, the risk of vertebral fracture after gastrectomy was the highest (HR: 1.16, 95% CI: 0.99-1.35). Patients with gastric cancer who underwent gastrectomy had a higher risk of osteoporotic fractures as compared to the general population. This suggests the need for bone metabolism management in patients with gastric cancer to prevent post-gastrectomy complications.

Effect of income level on stroke incidence and the mediated effect of simultaneous diagnosis of metabolic syndrome diseases; a nationwide cohort study in South Korea

BackgroundThis study aimed to determine whether a simultaneous diagnosis of main components of metabolic syndrome (MetS) (hypertension, diabetes mellitus, and dyslipidemia) plays a mediator between income level and stroke.MethodsWe used the National Health Insurance Service National Sample Cohort database from 2006 to 2015. The mediator variables were the number of main MetS components diagnosed simultaneously (two or more/three or more). We used a weighting approach method of causal mediation analysis to apply counterfactual frameworks to the Cox proportional hazards regression model.ResultsA total of 213,526 people were included with 1,690,665.3 person-years of followed up. Compared with the high-income group, the risk of being diagnosed with two or more components of MetS significantly increased in all other income groups [middle-income OR 1.05 (95% CI 1.02–1.08); low-income OR 1.09 (95% CI 1.05–1.12); Medical Aid beneficiaries OR 1.39 (95% CI 1.32–1.47)]. A lower level of income was significantly associated with a higher risk of stroke compared with the high-income group [middle-income HR 1.15 (95% CI 1.07–1.25); low-income HR 1.19 (95% CI 1.10–1.29); Medical Aid beneficiaries HR 1.63 (95% CI 1.48–1.80)]. In the Medical Aid beneficiaries, simultaneous diagnosis of the main metabolic components acted as a significant mediator between income levels and stroke incidence, with 26.6% mediated when diagnosed with two or more diseases and 21.1% when diagnosed with all three.ConclusionsCo-diagnosis of MetS components played a significant mediator role between income level and stroke incidence.

Comorbidities of nontuberculous mycobacteria infection in Korean adults: results from the National Health Insurance Service–National Sample Cohort (NHIS–NSC) database

BackgroundThe global prevalence and incidence of nontuberculous mycobacteria (NTM) infection are increasing. However, the prevalence of NTM infection-associated comorbidities remains understudied. Thus, we investigated the comorbidities associated with NTM infection using the National Health Insurance Service-National Sample Cohort (NHIS–NSC) 2.0 database of the National Health Insurance Service (NHIS).MethodsIn this case–control study, patients with NTM infection and controls aged 20–89 years of age were matched 1:4 by sex, age, region, and income. A total of 26 comorbidities were selected based on previous reports and claims data analysis. The distribution of comorbidities was compared between patients with NTM infection and controls by sex and age using logistic regression analysis.ResultsIn total, 893 patients (379 men and 514 women) with NTM infection (mean age, 56.1 years) and 3,572 controls (mean age, 55.6 years) were included. The odds ratio for prevalence of respiratory diseases, metabolic diseases, musculoskeletal disorders, gastrointestinal diseases, skin diseases, mental diseases, and neoplasms was significantly higher in patients with NTM infection than in the control group. Among comorbid diseases, the odds ratios (ORs) for the prevalence of the respiratory diseases such as bronchiectasis (OR [95% confidence interval (CI)]: 26.79 [19.69–36.45]) and interstitial pneumonitis (OR [95% CI]: 15.10 [7.15–31.89]) were the highest. No significant differences were observed in NTM infection-related comorbidities between men and women. In the younger age group (20–39 years old), the prevalence of respiratory and systemic diseases such as hypertension and diabetes was higher in the patient group than in the control group.ConclusionsNTM infection is associated with several respiratory and systemic diseases that should be considered when providing medical care to patients with NTM infection.

Association between migraine and risk of ocular motor cranial nerve palsy

To assess association between migraines and development of ocular motor cranial nerve palsy (CNP) and finding risk factors using the National Sample Cohort database from the Korea National Health Insurance Service. Data was analyzed from 4,234,341 medical screening examinees aged 20–90 years in 2009. Cox proportional hazard regression analysis was used to the adjusted hazard ratios (HR) for ocular motor CNP according to presence of migraine. Subgroup analysis was performed to evaluate effect of other factors on association of migraine with ocular motor CNP. A total of 5806 participants (0.14% of subjects) developed ocular motor CNP and were assigned to CNP group, 4,048,018 were assigned to control group, with an average of 8.22 ± 0.93 years of follow-up. Incidence of ocular motor CNP increased in migraine group compared to control. After adjusting potential confounding variables, HR for ocular motor CNP was 1.166 (confidence interval [CI] 1.013–1.343) in migraine group. Subgroups of relatively younger age less than 65 years (HR = 1.267, 95% CI 1.067–1.504), male gender (HR = 1.228, 95% CI 1.000–1.122), smokers (HR 1.426, 95% CI 1.127–1.803), and diabetes mellitus patients (HR = 1.378, 95% CI 1.045–1.378) showed a stronger association between migraines and development of ocular motor CNP. Our population-based cohort study demonstrated a significant association between presence of migraines and incidence of ocular motor CNP. Especially, relatively younger age, males, smokers, and diabetes patients with migraines could have a higher risk of developing ocular motor CNP.

Population-based study for the comorbidities and associated factors in Ménière’s disease

To date, no study has reported the objective metabolic laboratory findings worldwide or the comorbidities for Ménière’s disease (MD) using a population-based design in Asian populations. The aim of this study was to investigate the comorbidities and associated factors for MD using the Korean National Health Insurance Service database. This retrospective population-based study was conducted using a data from the National Sample Cohort database from 2009 to 2015. We only enrolled patients whose records showed a prescription for MD medicine and audiometry findings as well as an appropriate diagnostic code. We also included a matched cohort without MD who were enrolled randomly and matched for sex, age, year of diagnosis, income level, and residential area with the MD group with a ratio of 10:1. We evaluated comorbidities including autoimmune, allergic, metabolic diseases and cancer and the health screening data including general characteristics (height, weight, waist circumference, body mass index, and blood pressure), laboratory findings (fasting glucose, cholesterol, triglyceride, high-density lipoproteintryglyceride (HDL) cholesterol, low-density lipoproteintryglyceride cholesterol, hemoglobin, creatinine, aspartate aminotransferase and alanine aminotransferase, and gamma-glutamyltrans- peptidase (rGT)), and general health behaviors (smoking, alcohol, and exercise) of the MD group, and compared these characteristics with those of the MD-free control group. A total of 2,013 and 20,130 participants were included in the MD and MD-free control groups (1,640 and 15,458 for health screening data). We found the increase in incidence of allergic rhinitis and allergic asthma, decrease in systolic blood pressure, HDL cholesterol, and rGT, and less frequent alcohol consumption and less prevalent smoking in the MD group. No significant differences were observed between the groups in the incidence of autoimmune diseases, and cerebro- and cardiovascular disease as well as health screening data and objective laboratory findings. Inconsistence with published studies, the results of this study suggest that the autoimmunity and metabolic disorder, and skeletal growth might not be associated with the onset of MD. Another well-designed study for other races will be needed to the generalization of this study results.

Osteoporosis or fracture risk associated with thiazolidinedione and proton pump inhibitor co-administration in patients with type 2 diabetes mellitus.

Thiazolidinedione (TZD) and proton pump inhibitor (PPI) belong to classes of drugs that affect bone metabolism; however, few studies have investigated the effects of these drugs on bone metabolism. The aim of this study was to assess the risk of osteoporosis or fracture in patients with type 2 diabetes mellitus (T2DM) co-administered TZD and PPIs. This retrospective cohort study was conducted using the National Sample Cohort database from 2003 to 2013. We included adult patients with T2DM who were prescribed TZD and PPIs together for the first time. The Cox proportional hazard model was used to determine the risk ratio of fracture or osteoporosis in the co-administration cohort (TZD+PPI) compared with the TZD-only group (TZD). We adjusted for age, sex, use of other medications and other diseases that affect the bone. Of 9073 patients administered TZD, the number of eligible patients was 7240 (545TZD+PPI, 6695TZD-only). After 1:3 propensity score matching, 545 patients remained in the TZD+PPI group and 1635 in the TZD-only group. The risk of osteoporosis or fracture was significantly higher in the TZD+PPI cohort than in the TZD-only cohort. The adjusted hazard ratio (HR) for fracture or osteoporosis was 1.47 (95% CI 1.05-2.07). TZD and PPI use in women were associated with an increased risk of skeletal outcomes. TZD and PPI use were associated with an increased risk of osteoporosis or fracture in patients with T2DM.

Association between chronic kidney disease and open-angle glaucoma in South Korea: a 12-year nationwide retrospective cohort study

Various non-intraocular pressure factors have been identified as possible risk factors for open-angle glaucoma (OAG). However, there is still controversy around the association between OAG and chronic kidney disease (CKD). In this study, we used a nationwide cohort to investigate the risk of OAG in the 12 years following a diagnosis of CKD. This retrospective cohort study included 1,103,302 subjects from the Korean National Health Insurance Service National Sample Cohort database. The CKD group (n = 1318) included patients who were initially diagnosed with CKD between 2003 and 2008. The subjects in the comparison group were matched at a 1:5 ratio using propensity scores. In multivariate Cox regression analysis, a diagnosis of CKD was significantly associated with an increased incidence of OAG (hazard ratio [HR] = 1.546, 95% confidence interval [CI] 1.363–1.754, p < 0.001). Further analysis revealed that the risk of OAG increased with the severity of CKD (mild to moderate CKD [CKD stage 1–3]: HR = 1.280, 95% CI 1.077–1.521, p = 0.005; advanced CKD [CKD stage 4–5]: HR = 1.861, 95% CI 1.589–2.180, p < 0.001). In subgroup analysis, female CKD patients had a greater risk of developing OAG than males, and subjects with CKD aged ≥ 40 years were more likely to develop OAG compared with those aged < 40 years. Our study demonstrates that CKD is a significant risk factor for OAG and that severe CKD is associated with an increased risk of developing OAG.

Association Between Antihypertensive Use and Hospitalized Pneumonia in Patients With Stroke: A Korean Nationwide Population-Based Cohort Study.

BackgroundWe aimed to examine the association between antihypertensive use and the incidence of hospitalized pneumonia in patients with a history of stroke.MethodsIn this case-crossover study, we obtained data from the Korean National Health Insurance Service–National Sample Cohort database. We included the data of patients with history of stroke who were admitted with a disease code of pneumonia. We analyzed the patients’ exposure to antihypertensives in the 30 (single case period), 90–120, and 150–180 days (2 control periods) before the onset of pneumonia using conditional logistic regression analysis. Additionally, sensitivity analysis and subgroup analysis according to diabetes status, age, and documented disability were performed.ResultsAngiotensin II receptor blocker (ARB) use was associated with a reduced risk of hospitalized pneumonia (adjusted odds ratio [OR] [95% confidence interval; 95% CI]: 0.718 [0.576–0.894]). However, the use of angiotensin converting enzyme inhibitors and other antihypertensives were not associated with a change in hospitalized pneumonia incidence (adjusted OR [95% CI]: 0.902, [0.603–1.350] and 0.788 [0609–1.018], respectively). Subgroup analysis revealed that ARB use was associated with a reduced incidence of hospitalized pneumonia in patients with a history of stroke who were older than 65 years, but not in younger (≤ 65 years) group (adjusted OR [95% CI]: 0.687 [0.536–0.880]).ConclusionARB use is associated with a reduced incidence of hospitalized pneumonia in patients with a history of stroke, especially in older adults.

Prevalence and Current Status of Dental Treatment for Amelogenesis Imperfecta and Dentinogenesis Imperfecta using National Health Insurance Database

The aim of this study was to determine the prevalence and incidence and evaluate the current status of dental treatment of Amelogenesis imperfecta (AI) and Dentinogenesis imperfecta (DI) in South Korea. The data was based on National Health Insurance Service (NHIS)-National Sample Cohort Database (2002 - 2015) and Jeonbuk National University (JBNU) Dental Hospital (2011 - 2020). The NHIS data analysis showed prevalence of AI and DI were 11.6 and 2.4 per 100,000 people, respectively. The annual incidence of AI and DI for 2013 - 2015 were 2.2 and 0.5 per 100,000. There were no statistically significant differences regarding the number of visits, the reimbursable cost among AI, DI patients and others. In the patient analysis of the JBNU dental hospital, proportion of the reimbursable and non-reimbursable cost for AI patients were 12.1% and 87.9%, while DI patients accounted for 18.6% and 81.4%.