Insurance Service-National Health Screening Cohort Research Articles

Association between antibiotics use and osteoporotic fracture risk: a nationally representative retrospective cohort study

SummaryThis population-based retrospective cohort study aimed to estimate the association between antibiotic exposure and osteoporotic fracture risk. Long-term antibiotic use was associated with the risk of osteoporotic fracture. An increase in the number of antibiotic classes prescribed may also be associated with an increased osteoporotic fracture risk.PurposeThis study aims to examine the association between antibiotic usage and osteoporotic fractures in a large cohort of Korean adults, with a specific focus on the duration of antibiotic exposure and the number of antibiotic classes used.MethodsThis retrospective cohort study from the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) database from January 1, 2002, to December 31, 2019, included 167,370 Korean adults aged 50 years or older (mean [SD] age, 59.3 [7.82] years; 65,425 [39.09%] women). The cumulative antibiotic prescription days and the classes of antibiotics prescribed between 2004 and 2008 were exposure variables, respectively. The main outcome was a newly diagnosed osteoporotic fracture during follow-up. Cox proportional hazard regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the incident osteoporotic fractures associated with antibiotic exposure.ResultsThe antibiotic user group with 91 days had a higher risk of osteoporotic fracture in comparison to the antibiotic non-user group (aHR, 1.12; 95% CI, 1.03–1.21). Additionally, those who used more than four different antibiotic classes had an elevated risk of osteoporotic fracture compared to the non-user group (aHR, 1.10; 95% CI, 1.02–1.18).ConclusionThis extensive population-based cohort study conducted on a large population has identified an association between the utilization of antibiotics and an elevated risk of osteoporotic fractures. The cumulative days exposed to antibiotics and osteoporotic fractures may be positively associated.

Insulin Resistance and Impaired Insulin Secretion Predict Incident Diabetes: A Statistical Matching Application to the Two Korean Nationwide, Population-Representative Cohorts.

To evaluate whether insulin resistance and impaired insulin secretion are useful predictors of incident diabetes in Koreans using nationwide population-representative data to enhance data privacy. This study analyzed the data of individuals without diabetes aged >40 years from the Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2010 and 2015 and the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS). Owing to privacy concerns, these databases cannot be linked using direct identifiers. Therefore, we generated 10 synthetic datasets, followed by statistical matching with the NHIS-HEALS. Homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of β-cell function (HOMA-β) were used as indicators of insulin resistance and insulin secretory function, respectively, and diabetes onset was captured in NHIS-HEALS. A median of 4,580 (range, 4,463 to 4,761) adults were included in the analyses after statistical matching of 10 synthetic KNHANES and NHIS-HEALS datasets. During a mean follow-up duration of 5.8 years, a median of 4.7% (range, 4.3% to 5.0%) of the participants developed diabetes. Compared to the reference low-HOMA-IR/high-HOMA-β group, the high-HOMA-IR/low- HOMA-β group had the highest risk of diabetes, followed by high-HOMA-IR/high-HOMA-β group and low-HOMA-IR/low- HOMA-β group (median adjusted hazard ratio [ranges]: 3.36 [1.86 to 6.05], 1.81 [1.01 to 3.22], and 1.68 [0.93 to 3.04], respectively). Insulin resistance and impaired insulin secretion are robust predictors of diabetes in the Korean population. A retrospective cohort constructed by combining cross-sectional synthetic and longitudinal claims-based cohort data through statistical matching may be a reliable resource for studying the natural history of diabetes.

Higher high-density lipoprotein cholesterol levels increased vertebral osteoporotic fracture, but reduced hip fracture in men based on the National Health Insurance Service-National Health Screening Cohort

BACKGROUND CONTEXTLipids are currently known to play an important role in bone metabolism. PURPOSEThis study aimed to investigate the effect of high-density lipoprotein cholesterol (HDL-C) on osteoporotic fractures beyond its beneficial effects on the cardiovascular system. STUDY DESIGN/SETTINGThis was a retrospective, observational study that used data from the National Health Insurance Service-Health Screening cohort database. PATIENT SAMPLEThis study included 318,237 participants who were 50 years or older and with HDL-C levels of 10 to 200 mg/dL. OUTCOMES MEASURESPhysiologic measure—Diagnosis of osteoporotic fracture during the follow-up period. METHODSThe study participants were categorized into four quartiles according to baseline HDL-C levels. The Cox proportional hazards model was used to assess osteoporotic fracture risk according to HDL-C levels. RESULTSAfter full adjustment and with the Q1 group as the reference group, estimates of hazard ratios (HRs; 95% confidence intervals [CIs]) for any osteoporotic fracture in men were 1.03 (0.94–1.12), 1.02 (0.93–1.11), and 1.07 (0.98–1.18) for the Q2, Q3, and Q4 groups, respectively. After classifying osteoporotic fractures according to the body location, the fully adjusted HRs for vertebral and hip fractures in the men's Q4 groups were 1.16 (1.02–1.31) and 0.74 (0.57–0.96), respectively. In women, fully adjusted HRs (95% CIs) of the female Q4 group for any osteoporotic, vertebral, and hip fractures were 1.03 (0.95–1.11), 0.96 (0.86–1.07), and 1.06 (0.80–1.41), respectively. CONCLUSIONIn this study, HDL-C levels were positively associated with vertebral fractures in both men and women but inversely related to hip fractures in men. Therefore, monitoring the lipid profiles of patients with osteoporosis may be beneficial for the prevention of osteoporotic fractures.

Improved Oral Health Is Associated with a Lower Risk of Late Onset Ankylosing Spondylitis: A Nationwide Cohort Study.

Background: The aim of this study was to evaluate the association of oral health status and habits with the occurrence of ankylosing spondylitis (AS) in a nationwide population-based cohort in a longitudinal setting. Methods: A total of 2,415,963 individuals aged 40-79 years who underwent oral health examinations were included from the National Health Insurance Service-National Health Screening (NHIS-HEALS) cohort of Korea between 2003 and 2004. The occurrence of AS was analyzed according to the oral health status and oral hygiene habits. Results: Among 2,271,221 of the participants, AS occurred in 6366 (0.3%) participants over 16.7 years. The likelihood of AS was higher in participants who had periodontitis (hazard ratio [HR]: 1.33, 95% confidence interval [CI]: 1.20-1.46, p < 0.0001) and more missing teeth (HR: 1.68, 95% CI: 1.42-1.99, p < 0.0001). However, better oral hygiene habits such as frequent tooth brushing (HR: 0.77, 95% CI: 0.71-0.83, p < 0.0001) and a history of dental scaling within the last year (HR 0.88, 95% CI 0.82-0.95, p = 0.001) were associated with a lower occurrence of AS. Conclusions: Periodontitis and an increased number of missing teeth could be related to the occurrence of late-onset AS. Improved oral hygiene care may attenuate the likelihood of late-onset AS.

Cancer risk according to fasting blood glucose trajectories: a population-based cohort study

IntroductionDiabetes mellitus is known to increase the risk of cancer. Fasting blood glucose (FBG) levels can be changed over time. However, the association between FBG trajectory and cancer risk has...

Visit-to-visit variability in blood pressure and the risk of open-angle glaucoma in individuals without systemic hypertension: a nationwide population-based cohort study.

We aimed to evaluate the effect of visit-to-visit variability in blood pressure (BP) on the risk of open-angle glaucoma (OAG) in individuals without systemic hypertension using a population-based retrospective cohort study design. The Korean National Health Insurance Service-National Health Screening Cohort database, which collected data of 209,226 individuals between 2002 and 2015, was used to analyze the data of 140,910 eligible participants. The mean follow-up duration was 8.3 years. Visit-to-visit BP variability was assessed using standard deviation (SD), coefficient of variation (CV), and variability independent of the mean (VIM). Participants were categorized into four groups according to BP variability quartiles. We verified the effect of BP variability by comparing participants of the first to third quartiles of BP variability groups with those belonging to the fourth quartile group. A Cox proportional hazards model was used to determine the hazard ratio (HR) of BP variability in cases of newly diagnosed OAG. Moreover, we conducted subgroup analyses using baseline characteristics. In the multivariable analyses, BP variability did not significantly increase the risk of OAG development. However, subgroup analyses revealed significant interactions between age and systolic BP variability in the development of OAG (CV: p = 0.008; SD: p = 0.007). For participants aged <60 years, the risk of OAG development significantly increased with high systolic BP variability (CV: HR, 1.18; 95% confidence interval [CI], 1.00-1.39; p = 0.049). We observed a similar trend using the SD and VIM as the parameters for systolic BP variability. Higher visit-to-visit systolic BP variability was associated with an increased risk of OAG development in participants younger than 60 years of age without systemic hypertension. These results suggest that BP variability can be the considerable factor when assessing the risk of OAG, especially in relatively young people without systemic hypertension.

Weight maintenance and gain were significantly associated with lower risk of all-cause and cancer-related mortality in Korean adults who were newly diagnosed with cancer based on the Korean NHIS-HEALS cohort.

The burden of malignant neoplasms is increasing worldwide. Healthy lifestyles such as maintaining a healthy body weight are important to improve survival rate in cancer patients. This study was aimed to test the hypothesis that weight change affects mortality in patients newly diagnosed with cancer. This study was retrospectively designed based on the National Health Insurance Service-National Health Screening Cohort. A total of 1856 subjects aged at least 40 years who received a national health checkup within 6 months before cancer diagnosis was included. Study subjects were classified into 3 categories based on weight change before and after cancer diagnosis: weight loss, maintenance, and gain. Cox proportional hazards regression models were adopted to examine the association between weight change and mortality after adjusting for confounders. Compared to those experiencing weight loss, the adjusted hazards ratios (HRs) (95% confidence intervals [CIs]) for those experiencing weight maintenance were 0.327 (0.189-0.568) for all-cause mortality and 0.431 (0.215-0.867) for cancer-related mortality. The adjusted HRs (95% CIs) for those experiencing weight gain were 0.149 (0.044-0.505) for all-cause mortality and 0.289 (0.080-1.045) for cancer-related mortality. After stratifying according to baseline body mass index (BMI), weight maintenance and gain were negatively associated with all-cause mortality (0.286 [0.138-0.592] for weight maintenance and 0.119 [0.027-0.533] for weight gain) among those with a BMI < 25 kg/m2. Weight maintenance and gain reduced the risk of all-cause mortality in patients newly diagnosed with any cancer. In addition, weight maintenance was significantly related to cancer-related mortality.

Abstract 15002: Cardiovascular Disease Risk Prediction by Random Survival Forest: The Korean National Health Insurance Service-National Health Screening Cohort

Introduction: Risk prediction is critical for cardiovascular disease (CVD) prevention and management. Existing CVD risk prediction models including the Framingham Risk Score (FRS) are based on the Cox proportional hazard ratio regression. Adaptation of a data mining approach could improve the accuracy of CVD risk prediction by being free from the linearity assumption. The aim of study was to construct Korean population-based CVD risk prediction models using random survival forest and to compare their predictive accuracy to the FRS in a 14-year Korean cohort. Methods: This was a secondary data analysis using a Korean population-based cohort. Out of 463,783 eligible participants, 70% were selected for training dataset using stratified random sampling, and the remaining 30% served as test dataset. Random survival forest was adopted to build risk prediction models using the training dataset. The test dataset was used to test the validity of the new models and the FRS. Results: Three random forest-based models were developed, and they were good in discrimination in both men and women with the c-statistics ranging from 0.698 to 0.747 while the c-statistics for the FRS were 0.692 and 0.733 in men and women, respectively. All random forest-based models showed good calibration, whereas the FRS tended to overestimate the CVD risk for men. Conclusions: The random survival forest-based models showed comparable performance with the FRS in a Korean population-based cohort. Continuous efforts are needed to improve the accuracy of CVD risk prediction for the Korean population and to utilize CVD risk prediction in clinical practice.

Effect of Smoking Cessation on the Risk of Subarachnoid Hemorrhage: A Nested Case-Control Study in Korean Men.

Smoking is a well-established risk factor for subarachnoid hemorrhage (SAH), and current smokers have an increased risk of SAH. However, there are insufficient data on whether smoking cessation in current smokers reduces the risk of SAH. A nested case-control study was conducted based on the National Health Insurance Service-National Health Screening Cohort, which comprises nationwide health claims data and a national health screening program in Korea (2002-2019). We constructed a cohort of current male smokers without a history of stroke at the baseline health screening (2002-2003). From this cohort, cases were defined as individuals who experienced a nontraumatic SAH during the follow-up period up to 2019. Five controls were matched to each case using incidence density sampling. Smoking status (continuation or cessation) before the occurrence of SAH was evaluated using the repeated national health screening program. We conducted a multivariable conditional logistic regression analysis, adjusting for alcohol consumption, physical activity, body mass index, systolic blood pressure, and fasting blood glucose levels, to evaluate the association between SAH risk and smoking cessation. At baseline, there were 112 142 current male smokers. After excluding individuals with prior stroke or insufficient data, the cohort consisted of 105 223 eligible participants (mean age, 50.3±8.5 years). Among them, we identified 318 cases of SAH and 1590 matched controls. Those who quit smoking had a significantly lower risk of SAH compared with current smokers (adjusted odds ratio, 0.55 [95% CI, 0.41-0.73]). The risk of SAH decreased with a longer period of smoking cessation. The risk reduction with smoking cessation was consistent even among prior heavy smokers. Smoking cessation in current male smokers reduced the risk of SAH, and the risk reduction was greater as the cessation period increased. These findings warrant intensive efforts to encourage smokers, even heavy smokers, to quit.

Cancer risk according to fasting blood glucose trajectories: a population-based cohort study

Abstract Background Diabetes mellitus is known to increase the risk of cancer. Fasting blood glucose (FBG) levels can be changed over time. However, the association between FBG trajectory and cancer risk has been insufficiently studied. This research aims to examine the relationship between FBG trajectories and cancer risk in the Korean population. Methods We analyzed data from National Health Insurance Service-National Health Screening Cohort collected between 2002 and 2015. Group-based trajectory modeling was performed on 256,271 Koreans aged 40 to 79 who had participated in national health examinations at least three times from 2002 to 2007. After excluding patients with cancer history before 2008, we constructed a cancer-free cohort. The Cox proportional hazards model was applied to examine the association between FBG trajectories and cancer incidence, after adjusting covariates. Cancer case was defined as a person who was an outpatient thrice or was hospitalized once or more with a cancer diagnosis code within the first year of the claim. Results During the follow-up time (2008-2015), 18,991 cancer cases were identified. Four glucose trajectories were found: low-stable (mean of FBG at each wave &amp;lt;100 mg/dL), elevated-stable (113-124mg/dL), elevated-high (104-166mg/dL), and high-stable (&amp;gt;177mg/dL). The high-stable group had elevated risks in multiple myeloma, liver and gastrointestinal cancer, with hazard ratio (HR): 4.09 (95% confidence interval (CI): 1.40-11.95), HR: 1.68 (95%CI: 1.25-2.26) and HR: 1.27 (95%CI: 1.11-1.45) respectively. In elevated-stable group, the risk increased for all cancer (HR: 1.08, 95%CI: 1.02-1.16) and stomach cancer (HR: 1.24, 95%CI: 1.07-1.43). Significant associations were also found in the elevated-high group with oral (HR: 2.13, 95%CI: 1.01-4.47), liver (HR:1.50, 95%CI: 1.08-2.08) and pancreatic cancer (HR:1.99, 95%CI: 1.20-3.30). Conclusions Our study highlights that the uncontrolled high glucose level for many years may increase cancer risk. Key messages • Individuals in the prediabetes stage may be at an increased risk of developing cancer. • Fasting blood glucose trajectories may be a predictive factor for the development of digestive cancer.

Risk factors for colorectal cancer in a fecal immunochemical test-positive group: The National Health Insurance Service-National Health Screening Cohort.

Colorectal cancer (CRC) was the fourth most common cancer in Republic of Korea in 2019. It has a gradually increasing mortality rate, indicating the importance of screening for CRC. Among the various CRC screening test, fecal immunochemical test (FIT) is a simple yet most commonly used. Neverthelss, there have been only few long-term studies on subjects with FIT-positive. Therefore, in this study, we aimed to investigate the risk factors for CRC in FIT-positive patients using the National Health Insurance Service Bigdata database. Among 1737633 individuals with a FIT screening result for CRC in 2009, 101143 (5.82%) were confirmed to be FIT positive. The CRC incidence over 10years (up to 2018) of these participants was investigated using the National Cancer Registry. Out of the 101143 FIT-positive participants, 4395 (4.35%) were diagnosed with CRC. The FIT-positive patients who underwent a second round of screening showed a 5-year cumulative CRC incidence of approximately 1.25%, whereas those who did not showed an incidence of approximately 3.75%. Among the FIT-positive patients, the CRC incidence in the non-compliance group for the second round of screening was 2.8 times higher than that in the compliance group. In FIT-positive participants, non-compliance with the second round of screening was identified as a major risk factor for CRC development. It is necessary to establish appropriate strategies for managing risk factors for CRC in FIT-positive patients to increase the rate of compliance with the second round of CRC screening.

Predictive value of the Framingham steatosis index for cardiovascular risk: a nationwide population-based cohort study.

Non-alcoholic fatty liver disease (NAFLD) is common and is associated with cardiovascular (CV) disease and mortality. The Framingham steatosis index (FSI) was recently proposed as a diagnostic marker of NAFLD and was calculated from age, body mass index, triglyceride, aspartate aminotransferase, alanine aminotransferase, diabetes history, and hypertension status. We aimed to evaluate the predictive ability of FSI for CV risk using a large-scale population dataset from the Korean National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS). Among 514,866 individuals in the NHIS-HEALS, we excluded those who died, had a history of admission due to a CV event, and were heavy drinkers. The final study cohort comprised 283,427 participants. We employed both unadjusted and covariate-adjusted models in Cox proportional hazards regression analyses to determine the association between FSI and major adverse cardiovascular events (MACEs), CV events, and CV mortality. During a median follow-up of 5.9 years, we documented 9,674, 8,798, and 1,602 cases of MACEs, CV events, and CV mortality, respectively. The incidence of MACEs was 1.28%, 2.99%, 3.94%, and 4.82% in the first to fourth quartiles of FSI, respectively. The adjusted hazard ratios (95% confidence interval) for MACEs gradually and significantly increased with the FSI quartiles [1.302 (1.215-1.395) in Q2, 1.487 (1.390-1.590) in Q3, and 1.792 (1.680-1.911) in Q4], following an adjustment for conventional CV risk factors, including age, sex, smoking, drinking, physical activities, low-density lipoprotein cholesterol, estimated glomerular filtration rate, and waist circumference. Participants in the higher quartiles of FSI exhibited a noteworthy increase in the occurrence of CV event. However, upon adjusting for relevant risk factors, the association between FSI and CV mortality did not reach statistical significance. Our study suggests that the FSI, which is a surrogate marker of NAFLD, has a prognostic value for detecting individuals at higher risk of CV events.

Association between serum lipid levels and lower-extremity functions in older adults with and without Alzheimer's dementia in South Korea: A cross-sectional analysis

PurposeOlder adults with Alzheimer's dementia (AD) experience lower-extremity dysfunction. High serum lipid levels are a risk factor for AD. We investigated the association between serum lipid levels and lower-extremity function in older individuals with and without AD. MethodsIn this cross-sectional study, we enrolled 33,185 senior citizens (aged 66 years) who participated in the National Geriatric Screening Program, sampled from the Korean National Health Insurance Service-National Health Screening Cohort Database, between 2009 and 2015. Participants were dichotomized into 1) an AD group comprising individuals with the International Classification of Diseases, Tenth Revision, diagnostic codes F00, F00.0–F00.9, and G30, G30.0–G30.9; and 2) a control group comprising individuals without AD.Differences in the Timed Up and Go and One-Leg Standing results among the three levels (low, moderate, and high) of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol were evaluated between the groups. Logistic regression analysis was performed to estimate the odds of gait disorder considering clinical and lifestyle variables. ResultsIn participants with low LDL-C levels, increased LDL-C levels correlated with higher gait speed. In the AD group, balancing time with eyes open (BT-EO) was inversely correlated with TG levels in participants with low TG levels. In the control group, BT-EO was negatively correlated with TC levels in participants with low TC levels. ConclusionSerum lipid levels were significantly correlated with lower-extremity function in participants with and without AD but not with gait disorder in participants with AD.

Sex-specific Associations between Body Mass Index and Thyroid Cancer Incidence among Korean Adults.

The potential differences by sex in the association between body mass index (BMI) and thyroid cancer risk remain unconfirmed. Data from the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS; 2002-2015; population size = 510,619) and the Korean Multi-center Cancer Cohort (KMCC) data (1993-2015; population size = 19,026) were used. We constructed Cox regression models, adjusted for potential confounders, to evaluate the association between BMI and thyroid cancer incidence in each cohort, and assessed the consistency of the results. In the NHIS-HEALS, 1,351 and 4,609 incident thyroid cancer cases occurred during the follow-up among men and women, respectively. Compared with BMI of 18.5-22.9 kg/m2, BMI of 23.0-24.9 [no. of cases = 410; HR, 1.25; 95% confidence interval (CI), 1.08-1.44], 25.0-29.9 (no. of cases = 522; HR, 1.32; 95% CI, 1.15-1.51), and ≥30.0 kg/m2 (no. of cases = 48; HR, 1.93; 95% CI, 1.42-2.61) were associated with an increased risk of incident thyroid cancer among males. Among females, BMI of 23.0-24.9 (no. of cases = 1,300; HR, 1.17; 95% CI, 1.09-1.26) and 25.0-29.9 (no. of cases = 1,406; HR, 1.20; 95% CI, 1.11-1.29) were associated with incident thyroid cancer. The analyses using the KMCC demonstrated results consistent with wider CIs. Sex differences in the associations between BMI and thyroid cancer incidence were observed in Korean cohorts. BMI <23 kg/m2 may help prevent incident thyroid cancer, especially among men.

The Impact of BMI Changes on the Incidence of Glomerular Hematuria in Korean Adults: A Retrospective Study Based on the NHIS-HEALS Cohort

Obesity and recurrent hematuria are known risk factors for chronic kidney disease. However, there has been controversy on the association between obesity and glomerular hematuria. This study aimed to investigate the association between body mass index (BMI) and weight change and recurrent and persistent hematuria in glomerular disease using a large-scale, population-based Korean cohort. Data were collected from the National Health Insurance Service-National Health Screening Cohort. Cox proportional hazards regression analysis was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrent and persistent hematuria in glomerular disease according to the BMI group. Compared with the BMI 23-25 kg/m2 group, the HR (95% CI) for incident recurrent and persistent hematuria in glomerular disease was 0.921 (0.831-1.021) in the BMI <23 kg/m2 group, 0.915 (0.823-1.018) in the BMI 25-30 kg/m2 group, and 1.151 (0.907-1.462) in the BMI ≥30 kg/m2 group. Compared with the stable weight group, the HRs (95% CIs) for incident recurrent and persistent hematuria in glomerular disease were 1.364 (1.029-1.808) and 0.985 (0.733-1.325) in the significant weight loss and gain groups, respectively. Despite adjusting for confounders, this result remained significant. Baseline BMI was not associated with the risk of incident recurrent and persistent hematuria in glomerular disease. Weight loss greater than 10% was associated with the incidence of recurrent and persistent hematuria in glomerular disease. Therefore, maintaining an individual's weight could help prevent recurrent and persistent hematuria in glomerular disease in middle-aged and older Korean adults.

Association of Uncontrolled Hypertension or Diabetes Mellitus With Major Adverse Cardiovascular Events and Mortality in South Korea: Population-Based Cohort Study

Managing hypertension (HT) and diabetes mellitus (DM) is crucial to preventing cardiovascular diseases. Few studies have investigated the incidence and risk of cardiovascular diseases or mortality in uncontrolled HT or DM in the Asian population. Epidemiological studies of cardiovascular disease should be conducted with continuous consideration of the changing disease risk profiles, lifestyles, and socioeconomic status over time. We aimed to examine the association of uncontrolled HT or DM with the incidence of cardiovascular events or deaths from any cause. This population-based retrospective study was conducted using data from the Korean National Health Insurance Service-National Health Screening Cohort, including patients aged 40-79 years who participated in national screening from 2002 to 2003 and were followed up until 2015. The health screening period from 2002 to 2013 was stratified into 6 index periods in 2-year cycles, and the follow-up period from 2004 to 2015 was stratified accordingly into 6 subsequent 2-year periods. The incidence rates and hazard ratio (HR) for major adverse cardiovascular events (MACE) and death from any cause were estimated according to HT or DM control status. Extended Cox models with time-dependent variables updated every 2 years, including sociodemographic characteristics, blood pressure (BP), fasting blood glucose (FBG), medication prescription, and adherence, were used. Among the total cohort of 440,249 patients, 155,765 (35.38%) were in the uncontrolled HT or DM group. More than 60% of the patients with HT or DM who were prescribed medications did not achieve the target BP or FBG. The incidence of MACE was 10.8-15.5 and 9.6-13.3 per 1000 person-years in the uncontrolled DM and uncontrolled HT groups, respectively, and increased with age. In the uncontrolled HT and DM group, the incidence of MACE was high (15.2-17.5 per 1000 person-years) at a relatively young age and showed no age-related trend. Adjusted HR for MACE were 1.28 (95% CI 1.23-1.32) for the uncontrolled DM group, 1.32 (95% CI 1.29-1.35) for the uncontrolled HT group, and 1.54 (95% CI 1.47-1.60) for the uncontrolled HT and DM group. Adjusted HR for death from any cause were 1.05 (95% CI 1.01-1.10) for the uncontrolled DM group, 1.13 (95% CI 1.10-1.16) for the uncontrolled HT group, and 1.17 (95% CI 1.12-1.23) for the uncontrolled HT and DM group. This up-to-date evidence of cardiovascular epidemiology in South Korea serves as the basis for planning public health policies to prevent cardiovascular diseases. The high uncontrolled rates of HT or DM, regardless of medication prescription, have led us to suggest the need for a novel system for effective BP or glycemic control, such as a community-wide management program using mobile health technology.

Effect of metabolic health and obesity on all-cause death and CVD incidence in Korean adults: a retrospective cohort study

This study aimed to investigate the risk of all-cause mortality and incidence of CVD according to metabolic health and body mass index (BMI) in Korean adults. This study was retrospectively designed using the National Health Insurance Service-National Health Screening Cohort data. Participants were divided into six groups according to two category of metabolic syndrome and three categories of BMI. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the composite outcome (all-cause mortality and incidence of CVDs) were estimated using multivariable Cox proportional hazards regression models. 151,706 participants aged ≥ 40 years were enrolled; median follow-up period was 9.7 years in the study. Compared to metabolically healthy normal weight, the fully adjusted HRs (95% CIs) of metabolically healthy overweight, metabolically healthy obese, metabolically unhealthy normal weight, metabolically unhealthy overweight, and metabolically unhealthy obese for composite outcome were 1.07 (1.03–1.12), 1.12 (1.07–1.17), 1.33 (1.25–1.41), 1.28 (1.22–1.34), and 1.31 (1.26–1.37), respectively, in men, and 1.10 (1.05–1.16), 1.22 (1.16–1.29), 1.34 (1.26–1.43), 1.27 (1.19–1.34), and, 1.40 (1.34–1.47), respectively, in women. High BMI and metabolic unhealthiness were associated with an increased risk on the composite of all-cause mortality and incidence of CVD in both sexes.

Oral Health and Risk of Retinal Vascular Occlusions: A Nationwide Cohort Study.

Retinal vascular occlusions are a common cause of visual loss. The association between oral health and the risk of retinal vascular occlusions remains unknown. We investigated whether oral health was associated with the risk of retinal vascular occlusions. We conducted a retrospective cohort study including 138,484 participants who completed a national health screening program with an oral health examination from the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) 2002-2015. Oral health markers, such as the presence of periodontitis, tooth loss, and dental caries, and the frequency of daily tooth brushing, were evaluated. The primary outcome was the occurrence of retinal vascular occlusions up to December 2015. In total, 2533 participants developed retinal vascular occlusions (215 with retinal artery occlusion, 1686 with retinal vein occlusion, 632 with unspecified retinal vascular occlusion). In the multivariable Cox regression analysis, periodontitis was an independent risk factor for retinal vascular occlusions (adjusted hazard ratio: 1.18; 95% confidence interval: 1.02-1.36; p = 0.024). Frequent tooth brushing was negatively associated with the risk of retinal vascular occlusions (adjusted hazard ratio: 0.89; 95% confidence interval: 0.80-0.98; p = 0.022). Improving oral hygiene may contribute to the attenuation of the risk of retinal vascular occlusions.

Association between visit-to-visit fasting glycemic variability and depression: a retrospective cohort study in a representative Korean population without diabetes

Glycemic variability (GV) is a risk factor for depression in patients with diabetes. However, whether it is also a predictor of incident depression in people without diabetes remains unclear. We aimed to investigate the association between visit-to-visit variability in fasting serum glucose (FSG) levels and the incidence of depression among Koreans without diabetes. This retrospective cohort study included data of people without diabetes who did not have depression at baseline and had at least three FSG measurements (n = 264,480) extracted from the 2002–2007 Korean National Health Insurance Service–National Health Screening Cohort. GV was calculated as the average successive variability of FSG. Among 264,480 participants, 198,267 were observed during 2008–2013 and their hazard ratios (HR) of incident depression were calculated. Participants with the highest GV showed a higher risk of depression in fully adjusted models than those with the lowest GV (HR, 1.09; 95% CI, 1.02–1.16). The risk of incident depression heightened with increasing GV (p for trend < 0.001). Greater visit-to-visit GV may be associated with the risk of developing depression in people without diabetes. Conversely, maintaining steady FSG levels may reduce the risk of incident depression in people without diabetes.

Implications of metabolic health status and obesity on the risk of kidney cancer: A nationwide population-based cohort study.

This study evaluated the association between metabolic health status and incident kidney cancer among obese participants. A total of 514,866 individuals were included from the Korean National Health Insurance Service-National Health Screening Cohort. Changes in metabolic health status and obesity from the baseline examination in 2009-2010 to the next biannual examination in 2011-2012 were determined. Based on the status change, obese participants were divided into four groups: stable metabolically healthy obesity, metabolically healthy obesity to metabolically unhealthy obesity, metabolically unhealthy obesity to metabolically healthy obesity, and stable metabolically unhealthy obesity. The stable metabolically healthy obesity phenotype did not confer an increased risk of incident kidney cancer, compared to the stable metabolically healthy non-obese group. In contrast, the metabolically healthy obesity to metabolically unhealthy obesity group had a significantly higher risk of incident kidney cancer than the stable metabolically healthy non-obese group. Among patients with metabolically unhealthy obesity at baseline, those who transitioned to the metabolically healthy obese group had no increased risk of kidney cancer, whereas those who remained in metabolically unhealthy obesity status had a higher risk of incident kidney cancer than the stable metabolically healthy non-obese group. The transition or maintenance of metabolic health was a decisive factor for kidney cancer in obese patients. Maintaining or restoring metabolic health should be stressed upon in obese patients to reduce the risk of kidney cancer.