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Background: Hyperthyroidism is associated with an increased glomerular filtration rate (GFR) in the hyperdynamic state, which is reversible after restoring euthyroidism. However, long-term follow-up of renal dysfunction in patients with hyperthyroidism has not been performed.Methods: This was a retrospective cohort study using the Korean National Health Insurance database and biannual health checkup data. We included 41,778 Graves’ disease (GD) patients and 41,778 healthy controls, matched by age and sex. The incidences of end-stage renal disease (ESRD) were calculated in GD patients and controls. The cumulative dose and duration of antithyroid drugs (ATDs) were calculated for each patient and categorized into the highest, middle, and lowest tertiles.Results: Among 41,778 GD patients, 55 ESRD cases occurred during 268,552 person-years of follow-up. Relative to the controls, regardless of smoking, drinking, or comorbidities, including chronic kidney disease, GD patients had a 47% lower risk of developing ESRD (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.37 to 0.76). In particular, GD patients with a higher baseline GFR (≥90 mL/min/1.73 m2; HR, 0.33; 95% CI, 0.11 to 0.99), longer treatment duration (>33 months; HR, 0.31; 95% CI, 0.17 to 0.58) or higher cumulative dose (>16,463 mg; HR, 0.29; 95% CI, 0.15 to 0.57) of ATDs had a significantly reduced risk of ESRD.Conclusion: This was the first epidemiological study on the effect of GD on ESRD, and we demonstrated that GD population had a reduced risk for developing ESRD.

To report 20-year trends in incidence and survival of vulvar cancer in Korea.Using data from the Korean Central Cancer Registry, age-standardized incidence rates (ASRs) and annual percentage changes (APCs) were calculated. Net survival (NS) was estimated by the Pohar-Perme method, and conditional net survival (CNS) was calculated.A total of 2221 patients was diagnosed with vulvar cancer during the 1999-2018 period, with an ASR of 0.32 per 100,000 person-years. Among the cases, 51.4% were squamous cell carcinoma (SqCC), 21.3% were Paget disease, and 8.6% were basal cell carcinoma (BCC). There was an increase in incidence for all vulvar cancer (APC 2.4%, 95% CI 1.8-3.0). However, although BCC (APC 7.0%, 95% CI 3.3-10.8) and Paget disease (APC 5.9%, 95% CI 4.2-7.6) increased, SqCC did not (APC 0.2%, 95% CI -0.8-1.2). There was an increase in incidence in all age groups. The 5Y NS was 74.0% overall, and it did not improve significantly during the study period. The 5Y CNS of vulvar cancer increased continuously with time survived: from 74.0% (71.4-76.4) at baseline to 98.1% (95% CI, 85.4-99.8) at 5 years after diagnosis.The incidence of vulvar cancer in Korea showed a different pattern from those in the US and Europe: SqCC incidence was relatively low and remained stable, but the incidence of BCC and Paget's disease increased. Survival did not improve in the past two decades. Patients can be considered cured after surviving for 5 years.

Summary Objectives Previous studies of the relationships between female reproductive factors and osteoarthritis (OA) have shown conflicting results. In this study, we aimed to explore the relationships between reproductive factors and joint replacement arthroplasty of the knee (TKRA) and hip (THRA) in a large nationwide population-based cohort of postmenopausal Korean women. Methods We included 1,134,680 subjects who participated in national health examinations in 2009 in the study. The study outcomes were incident THRA or TKRA due to severe hip or knee OA. The relationships between reproductive factors and THRA or TKRA were evaluated using a multivariable-adjusted proportional hazards model. Results During a mean follow-up duration of 8.2 years, 1,610 incident THRA cases and 60,670 incident TKRA cases were observed. Later age at menarche, longer breastfeeding, HRT and OC use were associated with increased risk of TKRA for severe knee OA, while later age at menopause and longer reproductive span were associated with decreased risk. With regard to THRA for severe hip OA, later menarche, longer breastfeeding, HRT more than 5 years, and OC use more than 1 year were associated with higher risk. The associations between reproductive factors and severe OA were more pronounced in underweight and younger subjects. Conclusion We found that shorter estrogen exposure was associated with higher risk of TKRA due to severe knee OA, and such associations were more pronounced in underweight and younger subjects. The association between shorter estrogen exposure and THRA was not robust.

This nationwide population-based cohort study searched for demographic, comorbid, behavioral, and reproductive risk factors for idiopathic macular hole (MH) development using data provided by the Korean National Health Insurance Service. A total of 4,496,867 individuals aged 50–79 years who participated in the Korean National Health Screening Program in 2013 or 2014 were included. Participants were followed up until December 2018, and incident cases of idiopathic MH were identified. Prospective associations between incident idiopathic MH and various covariates were investigated using multivariable-adjusted Cox proportional hazard models. During an average follow-up period of 4.91 years, 3054 patients were newly diagnosed with idiopathic MHs. Women showed greater risk (hazard ratio of 1.71) and earlier presentation of idiopathic MH than men. Compared to the normal body mass index group, the obese group (≥ 25 kg/m2) showed a significantly lower risk of idiopathic MH. Among postmenopausal women, those with two or more children showed a greater risk of idiopathic MH than those who had not been pregnant, with a hazard ratio of 1.80. In conclusion, idiopathic MH occurred earlier and greater in women. Childbirth were associated with an increased risk of MH development, and obesity was associated with a lower risk of MH.

To evaluate the association between female reproductive factors and the incidence of exudative age-related macular degeneration (AMD).A total of 1,297,388 postmenopausal women over 50 years of age who participated in both national health screening and cancer screening in 2009 were identified using the Korea National Health Insurance System database. Data on female reproductive factors were collected using a self-administered questionnaire. Patients were followed up until 2018, and the incident cases of exudative AMD were identified. The hazard ratios and 95% confidence intervals for exudative AMD were estimated using the multivariable-adjusted Cox proportional hazard model.During a mean follow-up of 7.27 years, 4,086 patients were newly diagnosed with exudative AMD. The hazard ratio (95% confidence intervals) for exudative AMD was 1.14 (1.01-1.31) for a reproductive period ≥40 years compared with a reproductive period30 years, 1.72 (1.48-2.00) for patients with ≥5 years of hormone replacement therapy, and 1.29 (1.09-1.52) for those with 2 to 5 years of hormone replacement therapy compared with those who never underwent hormone replacement therapy.Female reproductive factors were associated with the risk of exudative AMD. Greater lifetime exposure to endogenous and exogenous estrogen was associated with a higher incidence of exudative AMD.

We aimed to evaluate the impacts of disability on the diagnosis, treatment, and prognosis of bile duct cancer (BDC) according to the severity and type of disability. Patients diagnosed with BDC were selected from an age- and sex-matched population (1:3 ratio) with or without disabilities from the National Disability Database, the Korean Central Cancer Registry, and the Korean National Health Insurance claims database. The cohort included 15,065 patients with BDC, with a significantly lower rate in those with severe disabilities than in people without or with mild disabilities (110.6 vs. 136.5 vs. 147.6 per 105 persons, respectively). People with severe disabilities were diagnosed with BDC at an earlier age but were less likely to undergo surgery (adjusted odds ratio (aOR) = 0.52, 95% confidence interval (CI): 0.45–0.61) or chemotherapy (aOR = 0.76, 95% CI: 0.61–0.95) compared to those without disabilities. This trend was more evident in patients with mental disabilities. The overall and cancer-specific mortality rates were higher in patients (especially women) with disabilities than in those without. There needs systemic approach to ensure equal access to quality cancer care for people with disabilities.

Although numerous studies have shown an association between alcohol consumption and cancer, how changes in drinking behavior increase or decrease the incidence of cancer is not well understood.To investigate the association between the reduction, cessation, or increase of alcohol consumption and the development of alcohol-related cancers and all cancers.This population-based cohort study analyzed adult beneficiaries in the Korean National Health Insurance Service. Participants (aged ≥40 years) included those who underwent a national health screening in both 2009 and 2011 and had available data on their drinking status. Data were analyzed from April 16 to July 6, 2020.Alcohol consumption level, which was self-reported by participants in health screening questionnaires, was categorized into none (0 g/d), mild (15 g/d), moderate (15-29.9 g/d), and heavy (≥30 g/d) drinking. Based on changes in alcohol consumption level from 2009 to 2011, participants were categorized into the following groups: nondrinker, sustainer, increaser, quitter, and reducer.The primary outcome was newly diagnosed alcohol-related cancers (including cancers of the head and neck, esophagus, colorectum, liver, larynx, and female breast), and the secondary outcome was all newly diagnosed cancers (except for thyroid cancer).Among the 4 513 746 participants (mean [SD] age, 53.6 [9.6] years; 2 324 172 [51.5%] men), the incidence rate of cancer was 7.7 per 1000 person-years during a median (IQR) follow-up of 6.4 (6.1-6.6) years. Compared with the sustainer groups at each drinking level, the increaser groups had a higher risk of alcohol-related cancers and all cancers. The increased alcohol-related cancer incidence was associated with dose; those who changed from nondrinking to mild (adjusted hazard ratio [aHR], 1.03; 95% CI, 1.00-1.06), moderate (aHR, 1.10; 95% CI, 1.02-1.18), or heavy (aHR, 1.34; 95% CI, 1.23-1.45) drinking levels had an associated higher risk than those who did not drink. Those with mild drinking levels who quit drinking had a lower risk of alcohol-related cancer (aHR, 0.96; 95% CI, 0.92-0.99) than those who sustained their drinking levels. Those with moderate (aHR, 1.07; 95% CI, 1.03-1.12) or heavy (aHR, 1.07; 95% CI, 1.02-1.12) drinking levels who quit drinking had a higher all cancer incidence than those who sustained their levels, but when quitting was sustained, this increase in risk disappeared. Compared with sustained heavy drinking, reduced heavy drinking levels to moderate levels (alcohol-related cancer: aHR, 0.91 [95% CI, 0.86-0.97]; all cancers: aHR, 0.96 [95% CI, 0.92-0.99]) or mild levels (alcohol-related cancer: aHR, 0.92 [95% CI, 0.86-0.98]; all cancers: aHR, 0.92 [95% CI, 0.89-0.96]) were associated with decreased cancer risk.Results of this study showed that increased alcohol consumption was associated with higher risks for alcohol-related and all cancers, whereas sustained quitting and reduced drinking were associated with lower risks of alcohol-related and all cancers. Alcohol cessation and reduction should be reinforced for the prevention of cancer.

This study aimed to determine the dose–response relationship between the levels of statin exposure and the incidence of Alzheimer’s disease (AD). We included 119,013 Korean adults (≥ 60 years old) using a database from the Korean National Health Insurance Service (2002–2013). Statin exposure was treated as a time-varying variable. Incidence of AD was defined by the first claim code for AD with anti-Alzheimer drugs. AD occurred in 9467 cases during a median 7.2 years of follow-up. Overall, statin use was not associated with an increased risk of AD incidence [adjusted hazard ratio (aHR) = 1.04; 95% confidence interval (CI) = 0.99–1.10]. When examined by level of statin exposure, statin prescription

BACKGROUND AND AIM Obesity was suggested to increase the incidence of gastric cancer (GC) in women, but results from previous studies were inconsistent. We investigated the relationship between obesity and the risk of GC according to menopausal status. METHODS We enrolled 1 418 180 premenopausal and 4 854 187 postmenopausal women aged ≥ 40 years using the Korean National Health Insurance System Cohort (2009-2014). We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for GC incidence according to body mass index (BMI) and waist circumference (WC) using the Cox proportional hazards models. RESULTS During the mean follow-up period of 7.2 years, 42 441 women were newly diagnosed with GC. Compared with the group with BMI 18.5-22.9 kg/m2 , the adjusted HRs (95% CIs) for GC in the groups with BMI

Background: Although diabetes is a well-known risk factor for hepatocellular carcinoma, exactly which metabolic parameters of diabetes are associated with hepatocellular carcinoma remain unexplored. In this study, we investigated the relationship between glucose variability (GV) and hepatocellular carcinoma in patients with diabetes through a nationwide population-based study. Methods: A population-based cohort study including 674,178 diabetic subjects participating in more than three health examinations within 5 years from the index year (2009 and 2010) were followed until the end of 2017. The coefficient of variation, SD, variability independent of the mean, and average real variability were calculated as GV indices. Results: During a median follow-up of 6.7 years, there were 5,494 cases of hepatocellular carcinoma. When groups were classified according to glucose level, the highest risk for hepatocellular carcinoma was observed when the basal blood glucose level was 180 mg/dL or greater [adjusted HR (aHR), 1.19; 95% confidence interval (CI), 1.08–1.31]. We observed increasing trends for the relationship between GV and hepatocellular carcinoma in multivariable Cox proportional analyses. The risk of hepatocellular carcinoma increased by 27% (aHR, 1.27; 95% CI, 1.17–1.38) for the highest quartile of GV relative to the lowest quartile. These findings were consistent regardless of the presence of chronic viral hepatitis or cirrhosis, alcohol consumption, or body mass index. Conclusions: GV was an independent predictor of hepatocellular carcinoma, even after adjusting for confounding factors. There was a linear relationship between increase in GV and prevalence of hepatocellular carcinoma. Impact: Visit-to-visit GV might be helpful for identifying patients with diabetes at high risk of hepatocellular carcinoma.

Background Physical frailty has previously been associated with adverse clinical outcomes in patients with end-stage renal disease (ESRD). This study aimed to determine whether impaired physical performance at baseline is associated with the incidence of ESRD, using a nationwide database. Methods The timed up-and-go (TUG) test was used to assess physical frailty in 1,552,781 66-year-old individuals, using health examination database records from the Korean National Health Insurance Service. As a primary endpoint, incident ESRD was defined operationally using healthcare claims data from the Korean Health Insurance Review and Assessment Service. Results Our results showed that baseline kidney function was significantly worse in individuals with TUG results of > 10 s compared to individuals with an intact TUG performance (≤10 s). Kaplan-Meier analysis showed a stepwise dose-response relationship between baseline physical performance and the incidence rate of ESRD (log-rank test P-value of Conclusion Poor baseline physical performance was associated with an increased risk of ESRD, suggesting possible interactions between systemic frailty and vascular aging processes.

PurposeSurvival probability changes over time in cancer survivors. This study examined conditional survival in patients undergoing curative resection for non-small cell lung cancer (NSCLC).Materials and MethodsFive-year conditional recurrence-free survival (CRFS), conditional overall survival (COS), and conditional relative survival (CRS) up to 10 years after surgery were calculated in patients who underwent NSCLC resection from 1994 to 2016. These rates were stratified according to age, sex, year of diagnosis, pathological stage, tumor histology, smoking status, comorbidity, and lung function.ResultsFive-year CRFS increased from 65.6% at baseline to 90.9% at 10 years after surgery. Early differences in 5-year CRFS according to stratified patient characteristics disappeared, except for age: older patients exhibited persistently lower 5-year CRFS. Five-year COS increased from 72.7% to 78.3% at 8 years and then decreased to 75.4% at 10 years. Five-year CRS increased from 79.0% at baseline to 86.8% at 10 years. Older age and higher pathologic stage were associated with lower 5-year COS and CRS up to 10 years after surgery. Female patients, those with adenocarcinoma histology, non-smokers, patient without comorbidities and had good lung function showed higher COS and CRS.ConclusionCRFS improved over time, but significant risk remained after 5 years. CRS slightly improved over time but did not reach 90%, suggesting significant excess mortality compared to the general population. Age and stage remained significant predictors of conditional survival several years after surgery. Our conditional survival estimates should help clinicians and patients make informed treatment and personal life decisions based on survivorship status.

Background: To examine the relationship between obesity measured by waist circumference (WC) and body mass index (BMI) and the incidence of colorectal cancer in premenopausal and postmenopausal women. Methods: A total of 1,418,180 premenopausal and 4,854,187 postmenopausal women without cancer at baseline and ages over 40 were identified using the Korean National Health Insurance System Cohort during 2009 to 2014. The hazard ratio (HR) for colorectal cancer incidence was assessed according to menopausal state using Cox proportional hazards models. Results: During a mean follow-up period of 7.2 years, 7,094 and 57,449 colorectal cancer cases occurred in premenopausal and postmenopausal women, respectively. Compared with the reference group (WC 65–75), the HRs [95% confidence interval (CI)] of colorectal cancer in WC 95 groups were 1.01 (0.91–1.11), 1.02 (0.97–1.07), 1.09 (1.00–1.18), and 1.31 (1.12–1.52), respectively, in premenopausal women and 1.01 (0.95–1.17), 1.09 (1.07–1.12), 1.19 (1.00–1.18), and 1.30 (1.25–1.35), respectively, in postmenopausal women. Compared with the reference group (BMI 18.5–22.9), HRs (95% CI) for colorectal cancer in BMI 30 groups were 0.99 (0.87–1.14), 0.99 (0.94–1.06), 0.98 (0.92–1.04), and 1.06 (0.92–1.20), respectively, in premenopausal women. In postmenopausal women, those values were 0.99 (0.93–1.05), 1.05 (1.03–1.08), 1.11 (1.09–1.13), and 1.20 (1.16–1.25), respectively. Conclusions: WC is associated with the risk of colorectal cancer in both groups of women, but this association was stronger in postmenopausal women than in premenopausal women. BMI increased the incidence of colorectal cancer only in postmenopausal women Impact: Obesity has a stronger relationship with colorectal cancer in postmenopausal women than in premenopausal women.

Background The number of patients with operable lung cancer with a history of percutaneous coronary intervention (PCI) has increased. However, cardiovascular outcomes and mortality, according to the time from PCI to surgery, and the follow‐up time after surgery are largely unknown. Here, we aimed to compare the cardiovascular outcomes and mortality of these patients with a history of PCI to those of patients without a history of PCI. Methods Using the Korean National Health Insurance Service Database, we selected 30 750 patients who underwent surgery for lung cancer between 2006 and 2014. Study outcome variables were all‐cause mortality, revascularization, intensive care unit (ICU) readmission, and stroke incidence. Patients were followed‐up until 2016. Results Of the 30 750 patients, 513 (1.7%) underwent PCI before surgery. The PCI group did not show an increased risk of death, ICU readmission, or stroke within one year of surgery, despite an increased risk of revascularization. However, one year after surgery, they showed a higher risk of death and revascularization than the non‐PCI group. The risk of revascularization was highest when the interval between PCI and surgery was 3 years. Conclusions Patients who underwent PCI before surgery for lung cancer were at a higher risk of death than those in the non‐PCI group at one year after surgery. In addition, they showed higher short‐ and long‐term risks of revascularization than patients in the non‐PCI group. Careful long‐term management of cardiovascular risk is necessary for this population., The PCI group had higher short‐ and long‐term risks of revascularization. Careful long‐term management of cardiovascular risk is required for the PCI group.

There are conflicting finds in the literature regarding the association of female estrogen status and the incidence of Parkinson’s disease (PD). We aimed to investigate whether female reproductive factors are associated with PD. Using the Korean National Health Insurance System database, 4,729,546 postmenopausal women without PD were identified. The new incidence of PD was defined as subjects with an ICD-10 code for PD (G20) and with a rare intractable disease registration code for PD (V124). The Cox proportional hazard models were used to evaluate the associations of various reproductive factors with incidence of PD. During the median follow-up of 5.84 years, 20,816 individuals were diagnosed with PD. An increased risk of PD was observed in subjects with a later age at menarche (≥ 17 years) compared with reference subjects (13 years ≤ age at menarche ≤ 14 years) (adjusted hazard ratio, aHR 1.10, 95% confidence interval, CI 1.05–1.16). As age at menopause increased, risk of PD decreased (P for trend 0.019). Consistently, decreased risk of PD was observed (aHR 0.91, 95% CI 0.85–0.96) in subjects with longer duration of fertility (≥ 40 years of age) compared with shorter duration of fertility (

We analyzed the patterns of diagnosis, treatment, and prognoses of acute myeloid leukemia (AML) patients with and without disabilities. The data were collected from the National Disability Database, the Korean Central Cancer Registry, and the Korean National Health Insurance claim database. We built a cohort of 2 776 450 people with disabilities and a nondisabled cohort of 8 329 350 people who were selected at a ratio of 1:3 by matching age and sex. From this population, adult patients who were diagnosed with AML were analyzed. The number of patients with AML were 26.74 per 100 000 in people without disabilities and 20.39 per 100 000 in those with disabilities (P, We report herein that individuals with disabilities have a relatively low diagnosis rate of acute myeloid leukemia (AML), undergo less active treatment, and have significantly lower survival rates than those without a disability.

BACKGROUND AND PURPOSE The aim was to investigate whether female reproductive factors are associated with dementia. METHODS In all, 4 696 633 post-menopausal women without dementia were identified using the Korean National Health Insurance System database. Data on reproductive factors were collected using a self-administered questionnaire. Dementia was determined using dementia diagnosis codes and anti-dementia drug prescription. Cox proportional hazards regression was conducted to assess the hazard ratio (HR) for dementia according to reproductive factors. RESULTS During a median follow-up of 5.74 years, there were 212 227 new cases of all-cause dementia (4.5%), 162 901 cases of Alzheimer's disease (3.5%) and 24 029 cases of vascular dementia (0.5%). The HR of dementia was 1.15 [95% confidence interval (CI) 1.03-1.16] for menarcheal age ≥17 years compared with menarcheal age 13-14 years, 0.79 (0.77-0.81) for menopausal age ≥55 years compared with menopausal age

Background Caregiving for childhood cancer survivors may be burdensome for caregivers and affect their physical health and health behaviors. However, studies examining health behaviors in caregivers of childhood cancer survivors are scarce. This study aimed to examine health behaviors of caregivers of childhood cancer survivors by comparing them with those of the general population, and analyze associated factors. Methods This study included 326 caregivers of childhood cancer survivors recruited from 3 major hospitals in South Korea and 1304 controls from the Korean National Health and Nutritional Examination Survey matched for age, sex, and education level. We compared health behaviors between the two groups by using conditional logistic regression analyses, and investigated factors associated with unhealthy behaviors in caregivers by using multiple logistic regression analyses. Results Caregivers were less likely to be physically inactive (aOR: 0.69, 95% CI: 0.51, 0.92) compared to controls, and this was more evident in women (aOR: 0.65, 95% CI: 0.45, 0.94). However, caregivers were more likely to be binge drinkers (aOR: 2.26, 95% CI: 1.73, 2.97), especially if they were men (aOR: 13.59, 95% CI: 8.09, 22.82). Factors associated with unhealthy behaviors in caregivers differed by the type of behavior. Current smoking risk was lower in female caregivers and in those with more comorbidities. Increasing age, female sex, higher education level, and lower household income were associated with lower risk of binge drinking. Higher household income and anxiety were associated with lower risk of physical inactivity, while depression was associated with higher risk of physical inactivity. Conclusions Caregivers of childhood cancer survivors were more likely to engage in binge drinking, but less likely to be physically inactive. Strategies to promote adherence to desirable health behaviors in caregivers are needed with consideration of their socioeconomic and clinical factors, such as number of comorbidities.

Background Reproductive factors and hormone use in postmenopausal women have been hypothesised to affect the risk of developing lung cancer, but the epidemiological evidence is inconsistent. Methods Using the Korean National Health Insurance System database, we identified 4,775,398 postmenopausal women older than 40 years who had undergone both cardiovascular health- and cancer screening between 1 January 2009 and 31 December 2014. Information about reproductive factors was obtained from a self-administered questionnaire. The risk of lung cancer was estimated using Cox proportional hazard regression models. Results During a median follow-up of 4.4 years, 16,556 women (15,223 non-smokers) were diagnosed with lung cancer. The risk of lung cancer was not significantly influenced by early menarche age (adjusted hazard ratio [aHR] 1.03 for menarche ≥18 vs. ≤14; 95% confidence interval [CI], 0.98–1.09) or late age at menopause (aHR 1.02 for menopause ≥55 vs. Conclusions No statistically significant association was found between reproductive factors and the risk of lung cancer in postmenopausal Korean women.

Background The timed up and go test (TUG) is one of the most widely used tests of mobility. We aimed to examine whether the TUG is associated with cardiovascular (CV) events, CV mortality, and all-cause mortality. Methods Subjects in the senior cohort database of the Korean National Health Insurance Service (2002–2013) who completed the TUG as part of the National Screening Program for Transitional Ages (NSPTA) during 2007–2008 were identified. An abnormal TUG result was defined as a time ≥ 10 s. Cox proportional hazard models were used to assess the associations between TUG results and CV events, CV mortality, and all-cause mortality. Results The mean follow-up period was 5.7 years. Incidence rates of CV events in the normal and abnormal TUG groups were 7.93 and 8.98 per 1000 person-years, while CV mortality rates were 0.96 and 1.51 per 1000 person-years, respectively. In a fully adjusted model, we found that abnormal TUG results were not associated with the incidences of CV events and CV mortality. However, abnormal TUG results (≥10 s) resulted in a 2.9-fold increase in CV mortality in women (adjusted hazard ratio 2.90, 95% confidence interval 1.15–7.30). Further, participants lacking certain CV risk factors, such as current cigarette smoking, obesity, or diabetes, had a higher CV mortality rate when TUG results were abnormal. Conclusions Abnormal TUG results in subjects aged 66 years were associated with future CV mortality in women and in subjects without obesity, diabetes, or cigarette smoking. In patient with mobility impairment, physicians should consider CV disease risk, especially in women.

Evidence of the association between anemia and risk of PD (Parkinson’s disease) have been accumulating. This study aimed to examine the relationship between anemia and risk of PD in Korean older adults. Korean adults aged 50 years or older who participated in the Korean National Screening Program (n = 12,342,278) between 2009 and 2013 were followed until 2015. Cox proportional hazards regression models were used to calculate the hazard ratio (HR) of PD, and participants were followed for a mean period of 5.0 years. At the end of follow-up, 3,844 adults were diagnosed with PD. After adjusting for potential confounders, participants with anemia had decreased risk of PD compared to adults without anemia (adjusted HR (aHR) 0.894, 95% CI: 0.809–0.989). Furthermore, aHR of PD was 0.698 (95% CI: 0.546–0.891) in moderate to severe anemia and 0.938 (95% CI: 0.843–1.044) in mild anemia. The protective effect of anemia was also more profound in men (aHR 0.888, 95% CI: 0.774–1.02) than in women (aHR 0.905, 95% CI: 0.782–1.048). In conclusion, anemia was associated with lower risk of PD, particularly for patients with moderate to severe anemia. Our study suggests that further studies may be needed to clarify the relationship between anemia and PD.

The purpose of this study was to evaluate the nationwide benefit and cost of the national cancer screening program (NCSP) for gastric cancer treatment.For this nationwide, population-based study, the Korean National Health Insurance Big Data Base, which included gastric cancer-related treatment information and the costs for all patients with gastric cancer who were 40 years old or older between 2004 and 2013, was restructured. Patients with gastric cancer who participated in the NCSP at least once (the screening group) were compared with those who did not participate in the NCSP (the nonscreening group).The screening group (n = 116,775) spent significantly less on medical care expenses than the nonscreening group (n = 74,927) during the 5 years since the initial treatment (P .0001). The screening group presented a significantly better prognosis for 5 and 9 years than the nonscreening group (P .0001). The screening group revealed a 41% decreased hazard ratio (P .0001) for death in comparison with the nonscreening group; the prognostic benefit became more obvious when treatment was started within the first 4 months after screening. The age-standardized mortality rate ratio of the screening group versus the nonscreening group was 0.62 (P .0001). The NCSP for gastric cancer required an average of 22,169,769 Korean Republic won (US $20,309) for 1 life-year saved, which was less than the average gross domestic product (GDP) per capita in Korea.The screening group had significantly lower medical care expenses and showed a significantly better prognosis than the nonscreening group. On the basis of the GDP per capita, the NCSP for gastric cancer was cost-effective for treatment prognosis.

This nationwide population-based cohort study evaluated the association between female reproductive factors and the incidence of retinal vein occlusion (RVO) and retinal artery occlusion (RAO) using data provided by the Korea National Health Insurance Service. A total of 2,289,347 postmenopausal women over 50 years of age who participated in both national health screening and cancer screening in 2013 or 2014 were included. Data on female reproductive factors, including age at menarche, age at menopause, parity, history of hormone replacement therapy, and oral contraceptive pill usage, were collected. Patients were followed up until December 2018, and incident cases of RVO and RAO were identified using registered diagnostic codes from claim data. During an average follow-up period of 4.90 years, 7461 and 1603 patients were newly diagnosed with RVO and RAO, respectively. In the multivariable-adjusted Cox proportional hazard model, patients who experienced menopause after 55 years of age had a lower risk of RVO and RAO development compared to those who had menopause before 45 years of age, with a hazard ratio (95% confidence interval) of 0.83 (0.76–0.95) for RVO and 0.80 (0.66‒0.98) for RAO. In conclusion, early menopause was an independent risk factor for future development of RVO and RAO.

Background There are conflicting results regarding endogenous estrogen exposure and risk of incident nontuberculous mycobacterial pulmonary disease (NTM-PD). In addition, evidence on impact of hormone replacement therapy (HRT) on risk of NTM-PD is lacking. This study aimed to evaluate the impacts of endogenous estrogen exposure and HRT on risk of NTM-PD in postmenopausal women. Methods This population-based cohort study comprised 1 400 095 postmenopausal women without previous NTM-PD who participated in the 2009 national health screening exam in South Korea. The cohort was followed until the date of incident NTM-PD, death, or December 2018. We evaluated whether lifetime endogenous estrogen exposure and HRT were associated with incident NTM-PD. Endogenous estrogen exposure was evaluated using age at menarche and menopause and reproductive period (duration between age at menarche and age at menopause). Results During a median of 8.4 (interquartile range, 8.2–8.7) years of follow-up, 0.1% of participants (1818/1 400 095) developed NTM-PD, with an incidence rate of 0.15/1000 person-years. Multivariable Cox regression analyses showed no significant relationship between endogenous estrogen exposure (age at menarche, age at menopause, and reproductive period) and risk of NTM-PD. In contrast, duration of HRT showed a significant dose–response relationship with incident NTM-PD even after adjustment for demographics and reproductive factors (adjusted hazard ratio [95% CI]: 1.30 [1.12–1.51] in HRT for Conclusions While there was no significant association with endogenous estrogen exposure, HRT was monotonically associated with increased risk of NTM-PD in postmenopausal women.

Although the oestrogen level is thought to be involved in the occurrence of bronchiectasis, limited data are available on the relationship between female reproductive factors and the risk of bronchiectasis. We performed a population-based retrospective cohort study of 959,523 premenopausal women and 1,362,401 postmenopausal women without a previous history of bronchiectasis who participated in a health screening exam in 2009 in South Korea. In premenopausal women, compared with a later age at menarche (≥16 years), an earlier menarche (

Introduction Not much is known regarding the disparities in cancer care between women with and without disabilities. Objectives The aim of this study was to investigate the potential disparities in the diagnosis, treatment, and survival of women with cervical cancer with and without disabilities. Methods We performed a retrospective cohort study and linked the National Disability Database, Korean Central Cancer Registry, and Korean National Health Insurance claims database. Charlson comorbidity index was used for adjusting the comorbidity. The study population comprised 3 185 women with disabilities (physical/brain, communication, mental, cardiopulmonary, and other impairment) who were diagnosed with cervical cancer and 13 582 age- and sex-matched women without disability who were diagnosed with cervical cancer for comparison. Results Distant metastatic stage (7.7% vs 3.7%) and unknown stage (16.1% vs 7.0%) were more common in cervical cancer women with grade 1 disabilities, compared with women without disabilities. Women with cervical cancer with disabilities were less likely to undergo surgery (adjusted odds ratio (aOR) 0.81, 95% confidence interval (CI) 0.73–0.90) or chemotherapy (aOR 0.86, 95% CI 0.77–0.97). Lower rate of surgery was more evident in patients with physical/brain impairment (aOR 0.46, 95% CI 0.37–0.58) and severe mental impairment (aOR 0.57, 95% CI 0.41–0.81). The overall mortality risk was also higher in patients with disabilities (adjusted hazard ratio (aHR) 1.36, 95% CI 1.25–1.48). Conclusion Women with cervical cancer with disabilities, especially with severe disabilities, were diagnosed at later stages, received less treatment, and had higher mortality rates, compared with patients who lacked disabilities. Social support and policies, along with education for women with disabilities, their families, and healthcare professionals, are needed to improve these disparities.

The purpose of this study was to estimate 5-year conditional relative survival (5Y CRS) rates of endometrial cancer (EC) in Korea accounting for time already survived. Subgroup-specific estimates stratified by various patient characteristics were also presented.Using the data from the Korean Central Cancer Registry, 5Y CRS rates were calculated in patients who were diagnosed with EC between 1998 and 2017. The CRS rates were presented by year of diagnosis, age at diagnosis, histology, cancer stage, and treatment received.The 5-year relative survival rate at the time of diagnosis was 89.0% for all cases. The probability of surviving an additional 5 years (i.e., 5Y CRS), if the patient survived 1, 2, 3, 4, and 5 years after diagnosis was 91.8%, 94.1%, 95.6%, 96.5%, and 97.3%, respectively. Patients with poor initial prognoses, i.e., those who were older, had non-endometrioid histology, and high stage, showed the largest improvements in 5Y CRS, reaching90% for most subgroups, except those with serous histology (88.4%) and distant stage (77.7%). Patients aged ≥70 years had the highest probability of death in the 1st and 2nd years after diagnosis (13.8 and 11.0%), but the conditional probability of death in the 3rd, 4th, and 5th years declined rapidly to 7.3%, 4.5%, and 3.7%, respectively.The CRS rates for patients with EC improved with increased time elapsed from diagnosis. The greatest improvements in 5Y CRS were observed among patients who were older, those with non-endometrioid histology, and those with more advanced disease.

Alcohol consumption has complex effects on myocardial infarction (MI) and ischemic stroke. We investigated the difference in associations according to drinking patterns (drinking frequency vs. amount per occasion) and sex.This population-based retrospective study included 11,595,191 subjects participating in national health examinations between 2009 and 2010. Using Cox regression analyses, we calculated MI and ischemic stroke risk according to weekly alcohol consumption, drinking frequency, and amount per occasion.For MI, all weekly alcohol consumption amounts showed lower risk compared to non-drinkers: mild (adjusted hazard ratio [aHR], 0.78; 95% confidence intervals [CI], 0.77-0.79), moderate (aHR, 0.71; 95% CI, 0.70-0.73), and heavy (aHR, 0.74; 95% CI, 0.72-0.76). Drinking frequency and amount per occasion did not differ in MI risk. However, women showed increased risk with heavy drinking and ≥8 drinks per occasion. For ischemic stroke, a J-shaped association was observed for weekly alcohol consumption: mild (aHR, 0.91; 95% CI, 0.90-0.92), moderate (aHR, 0.94; 95% CI, 0.93-0.96), and heavy (aHR, 1.04; 95% CI, 1.02-1.06). Among women, ischemic stroke risk began to increase with moderate drinking. Given similar weekly alcohol consumption levels, ischemic stroke risk increased with higher frequency of drinking, not with amount per occasion.Drinking frequency may be a more important risk factor for ischemic stroke than amount per occasion. Among women, the protective effect of alcohol against MI was not evident in heavy amounts, and the risk of ischemic stroke began to increase at lower levels compared to men.

Background The association between nonalcoholic fatty liver disease (NAFLD) and Parkinson's disease (PD) remains uncertain. This study sought to assess the sex-specific association between NAFLD and PD risk considering that sex is an important factor in both conditions. Methods We included 2,651,169 men and 2,998,904 women (≥40 years of age) who underwent health examinations in 2009 using database of the Korean National Health Insurance Service. To define NAFLD, the Fatty Liver Index (FLI) was used and a score of at least 60 points was regarded as suggesting the presence of NAFLD. Cox proportional hazards analyses were performed to evaluate the association between the presence of NAFLD/each component of FLI and the risk of PD. All analyses were stratified by sex. Results The median follow-up duration was 7.3 years in both men and women. Of the total study population, 23,233 patients with PD (10,578 men and 12,655 women) were identified. Among men, a decreased risk of PD was observed in those with NAFLD [adjusted hazard ratio (aHR): 0.86, 95% confidence interval (CI): 0.82–0.91]. In contrast, among women, an increased risk of PD was observed in those with NAFLD (aHR: 1.09, 95% CI: 1.02–1.16). This different association according to sex was more prominent among younger participants but was not significant in the old age group. Conclusions NAFLD defined by FLI is differently associated with the risk of PD by sex (i.e., low risk of PD in men with NAFLD vs. high risk of PD in women with NAFLD).

Purpose Implementation of screening program may lead to increased health disparity within the population if participation differs by socioeconomic status. In Korea, colorectal cancer screening is provided at no or minimal cost to all people over 50 by National Cancer Screening Program. We investigated colorectal cancer screening participation rate and its trend over the last 10 years in relation to disabilities. Materials and methods We linked national disability registration data with National Cancer Screening Program data. Age, sex-standardized participation rates were analyzed by type and severity of disability for each year, and factors associated with colorectal cancer screening participation were examined by multivariate logistic regression. Results Age, sex-standardized participation rate in people without disability increased from 16.2 to 33.9% (change, +17.7), but it increased from 12.7% to 27.2% (change, +14.5) among people with severe disability. People with severe disabilities showed a markedly lower colorectal cancer screening participation rate than people without disability (adjusted odds ratio [aOR], 0.714; 95% confidence interval, 0.713 to 0.720). People with autism (aOR, 0.468), renal failure (aOR, 0.498), brain injury (aOR, 0.581), ostomy (aOR, 0.602), and intellectual disability (aOR, 0.610) showed the lowest participation rates. Conclusion Despite the availability of a National Cancer Screening Program and overall increase of its usage in the Korean population, a significant disparity was found in colorectal cancer screening participation, especially in people with severe disabilities and or several specific types of disabilities. Greater effort is needed to identify the barriers faced by these particularly vulnerable groups and develop targeted interventions to reduce inequality.

An increased risk of influenza-related morbidity and mortality in childhood cancer survivors could be significantly reduced through vaccinations. This study aimed to examine influenza vaccination practices by caregivers of childhood cancer survivors. Study subjects were 364 caregivers, recruited at three major hospitals in South Korea. We collected demographic and medical information through self-administered questionnaires, along with clinical information of childhood cancer survivors by reviewing medical records. Multiple logistic regression analysis was performed to analyze factors associated with influenza vaccination of caregivers. A total of 55.2% of caregivers had received influenza vaccination at least once and 24.2% had received yearly influenza vaccinations during the last 3 years. Caregivers with highest education level were more likely to receive influenza vaccination than caregivers with lowest education level: aOR (95% CI) was 3.42 (1.17, 9.99) for ever-receipt of vaccination and 3.33 (1.15, 9.58) for yearly vaccination. One-year increase in caregiver age was inversely associated with ever-receipt of vaccination (aOR (95% CI), 0.94 (0.90, 0.98)) as well as yearly vaccination (aOR (95% CI), 0.92 (0.88, 0.97)). Increasing time lapse since the end of treatment was also associated with lower vaccinations. Influenza vaccination rates of childhood cancer survivor caregivers were suboptimal. Time lapse after completing cancer treatment, caregiver age, and educational level were independently associated with receipt of influenza vaccination by caregivers. To promote influenza vaccination in caregivers of childhood cancer survivors to prevent influenza-related morbidity and mortality in childhood cancer survivors is necessary.

Using the national disability registration linked to the cancer screening database in Korea, we examined (1) trends in the gastric cancer screening rate among people with disabilities over time, and (2) whether gastric cancer screening participation and modalities differed according to presence, severity, and type of disability. We examined gastric cancer screening participation rates among individuals with registered disability, from 2006 to 2015. The age- and sex-adjusted rate for gastric cancer screening in people with disabilities increased from 25.9% in 2006 to 51.9% in 2015 (change: + 26.0%). During the same period, screening rates among people without disability improved from 24.7 to 56.5% (change: + 31.8%). Disability was associated with a screening rate [adjusted odds ratio (aOR) 0.89, 95% confidence interval (CI), 0.88–0.89]. Screening rates were markedly lower among people with severe disabilities (aOR 0.58, 95% CI 0.57–0.58) and people with autism (aOR 0.36, 95% CI 0.25–0.52), renal failure (aOR 0.39, 95% CI 0.38–0.39), brain injury (aOR 0.41, 95% CI 0.40–0.41), ostomy problems (aOR 0.53, 95% CI 0.51–0.55), intellectual disabilities (aOR 0.54, 95% CI 0.53–0.54), or mental disorders (aOR 0.55, 95% CI 0.54–0.56). The use of gastroscopy as the initial screening modality in people with disabilities was lower than in people without a disability. In spite of the availability of national gastric cancer screening program, we found significant disparities in gastric cancer screening participation, especially among people with severe disabilities and those with renal failure or brain-related/mental disabilities.

This study was designed to compare the risk of dementia, including Alzheimer’s disease (AD) and vascular dementia (VaD), between gastric cancer patients who underwent gastrectomy and the general population. All patients (n = 63,998) aged ≥ 50 years who received a diagnosis of gastric cancer and underwent curative gastrectomy between 2007 and 2012 and a noncancer control population (n = 203,276), matched by age and sex, were identified from the Korean National Health Insurance Services and traced until 2017. Hazard ratios and 95% confidence intervals for dementia were calculated with a Cox regression analysis. Gastric cancer patients who received a gastrectomy showed an increased risk of AD [adjusted hazard ration (aHR) 1.08, 95% confidence interval (CI) 1.03–1.14], and the risk was especially marked for those who received a total gastrectomy (aHR 1.39, 95% CI 1.25–1.54). Gastric cancer survivors showed a decreased risk for VaD (aHR 0.85; 95% CI 0.73–0.98) regardless of operation type. Those who received continual vitamin B12 supplementation after a total gastrectomy were less likely than controls to develop AD (aHR 0.71; 95% CI 0.54–0.92). Compared with controls, gastric cancer patients who received a total gastrectomy had an increased incidence of AD and a decreased risk of VaD. Our results suggest that vitamin B12 deficiency might play a role in the development of AD and highlight the need for vitamin B12 supplementation after total gastrectomy.

Objectives With advances in lung cancer treatments, the number of lung cancer survivors has increased. As cardiovascular diseases (CVD) are some of the major causes of non-cancer deaths, CVD management is an integral part of cancer survivorship care. However, there is sparsity of data on cardiovascular risk in lung cancer survivors who underwent lung cancer surgery. We aimed to compare the incidence of CVD between lung cancer survivors and the general non-cancer population. Materials and methods Using the Korean National Health Insurance Service Database, we selected 20,458 patients who underwent surgery for lung cancer between 2007 and 2013. Study outcome variables were coronary heart disease (CHD), myocardial infarction (MI), ischemic stroke (IS), and death. Patients were followed until 2016. Results A total of 20,458 lung cancer patients undergoing lung cancer surgery were compared to 27,321 non-cancer control subjects. Lung cancer survivors showed a greater risk for all cardiovascular (CV) events (adjusted hazard ratio [aHR] = 1.27, 95% confidence interval [CI]: 1.19–1.36), CHD (aHR = 1.26, 95% CI: 1.16–1.36), and IS (aHR = 1.22, 95% CI: 1.07–1.39). Chemotherapy and radiotherapy were associated with an increased risk of CV events, CHD, and MI. Lung cancer survivors who were CV event-free for one year, and up to three years, were still at a higher risk for all CV events compared to the non-cancer control population. Conclusions Lung cancer survivors showed an increased risk of CHD and IS compared with the general non-cancer population. Therefore, paying careful attention to cardiovascular risk in lung cancer survivors is suggested, especially for those who receive chemotherapy and/or radiotherapy, in order to ensure both early and long-term survivorship.

BACKGROUND There have been conflicting results on the association between statin use and Parkinson's disease (PD) incidence. OBJECTIVES This study investigated the association between time-varying status of statin use and incidence of PD while considering the dose-response relationship and total cholesterol level. METHODS Using the database of the Korean National Health Insurance Service from 2002 to 2015, we examined 76,043 subjects (≥60 years old) free of PD, dementia, and stroke at baseline. The dose of statin use was classified into the following four 6-month categories (

PURPOSE This study aimed to determine whether the diagnosis, treatment approach, and prognosis of multiple myeloma (MM) vary according to the presence and type of disability. Materials and Methods Demographic, socioeconomic, and medical data were obtained from the National Disability Database, the Korean Central Cancer Registry, and the Korean National Health Insurance claims database. An age- and sex-matched cohort was established using a 1:3 ratio constituted with 2,776,450 people with disabilities and 8,329,350 people without disabilities. Adult patients diagnosed with MM were subsequently selected from this cohort. Disabilities were categorized as physical, communication, intellectual or psychological, and affecting the major internal organs. RESULTS The cohort included 4,090 patients with MM, with a significantly lower rate per 100,000 persons among people with disabilities than among people without disabilities (29.1 vs. 39.4, p < 0.001). People with disabilities were more likely to undergo dialysis treatment at the time of diagnosis (16.3% vs. 10.0%, p < 0.001), but were less likely to undergo autologous stem cell transplantation (37.5% vs. 43.7%, p=0.072). This trend was more evident among patients with intellectual or psychological disabilities. The median overall survival among patients with disabilities was significantly shorter than that among patients without disabilities (36.8 months vs. 51.2 months, p < 0.001). CONCLUSION In Korea, people with disabilities generally have a lower rate of MM diagnosis, receive less intensive treatment, and have a lower survival rate than people without disabilities.

Anemia is a common health problem in older adults and is associated with risk factors for fracture such as low physical function and low bone mass. The aim of this study was to examine the relationship between anemia and fracture risk in older adults. We conducted a retrospective cohort study from 2003 to 2013. The participants were community-dwelling Korean adults aged 65 years and older who participated in the National Health Screening Program (n = 72,131) between 2003 and 2008. Anemia (

Background: Among the potential modifiable risk factors, the association between alcohol consumption and the risk of multiple myeloma remains controversial. We investigated the effects of weekly average alcohol consumption and drinking pattern on the risk of multiple myeloma using a nationwide representative database. Methods: We identified 11,737,467 subjects who participated in the Korean National Health Screening Program in 2009 and 2010. Cox regression analyses were performed to calculate the risk of multiple myeloma according to weekly alcohol consumption, drinking frequency, and amount per session. Results: During a mean follow-up period of 6.8 years after a one-year time lag, 6,981 subjects (3,921 men and 3,060 women) were diagnosed with multiple myeloma. Compared with nondrinkers, all drinkers were at a significantly lower risk for multiple myeloma. The risk of multiple myeloma was reduced in a dose-dependent manner: mild drinkers [adjusted HR (aHR), 0.89; 95% confidence interval (CI), 0.84–0.95], moderate drinkers (aHR, 0.83; 95% CI, 0.76–0.91), and heavy drinkers (aHR, 0.76; 95% CI, 0.69–0.85). Furthermore, both drinking frequency and amount per drinking session showed inverse association with the risk of multiple myeloma. Conclusions: Our large population-based study suggested an inverse dose-dependent association between total average alcohol consumption and the risk of multiple myeloma, and drinking frequency and amount per drinking session seemed to not differ in their relative contribution to the risk of multiple myeloma. Impact: On the basis of the unprecedentedly large number of study population analyzed in this study, our study provides solid epidemiologic evidence of alcohol consumption on multiple myeloma risk.

This study is to elucidate the associations between female reproductive factors and pterygium. A total of 1,339,969 postmenopausal women in a retrospective cohort of Korean National Health Insurance Service data on ages 40 and above in 2009 was included. Cox proportional hazards regression was conducted to assess the hazard ratio (HR) for pterygium according to reproductive factors. Late menarche, early menopause, short reproductive period, increasing parity (≥ 2 children), breastfeeding (≥ 6 months), and no use of hormone replacement therapy (HRT) or oral contraceptive (OC) were significantly associated with risk of pterygium. In multivariate analysis, the HR for pterygium was 1.764 (95% confidence interval [CI], 1.529–2.035) for menarche age ≥ 17 years (reference: menarche age

Increasing evidence suggests that obstructive sleep apnea (OSA) is a metabolic syndrome-related disease; however, the association between nonalcoholic fatty liver disease (NAFLD) and OSA is not firmly established. In this study, we investigated the relationship between NAFLD and OSA in a general population drawn from a nationwide population-based cohort. Data from the Korean National Health Insurance System between January 2009 and December 2009 were analyzed using Cox proportional hazards model. NAFLD was defined as a fatty liver index (FLI) ≥ 60 in patients without excessive alcohol consumption (who were excluded from the study). Newly diagnosed OSA during follow-up was identified using claims data. Among the 8,116,524 participants, 22.6% had an FLI score of 30–60 and 11.5% had an FLI ≥ 60. During median follow-up of 6.3 years, 45,143 cases of incident OSA occurred. In multivariable analysis, the risk of OSA was significantly higher in the higher FLI groups (adjusted hazard ratio [aHR] 1.15, 95% confidence interval [CI] 1.12–1.18 for FLI 30–60 and aHR 1.21, 95% CI 1.17–1.26 for FLI ≥ 60). These findings were consistent regardless of body mass index and presence of abdominal obesity. In conclusion, a high FLI score may help identify individuals with a high risk of OSA. Understanding the association between NAFLD and OSA may have clinical implications for risk-stratification of individuals with NAFLD.

Background Nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of diabetes but has been rarely investigated in young adults. In this study, we investigated the relationship between NAFLD and incident diabetes risk in young adults using nationwide Korean population data. Methods This population-based cohort study from the Korean National Health Insurance Service included adults aged 20 through 39 years who underwent a health examination from 2009 to 2012. NAFLD was defined as a fatty liver index (FLI) ≥60 in the absence of alcohol consumption of ≥30 g/day. Newly diagnosed diabetes during follow-up was identified using claims data. Cox regression was used to calculate the hazard ratio for incident diabetes after adjusting for classical confounders. Findings Among the 5,254,786 participants, 9.3% had an FLI ≥60. During the median follow-up of 8.6 years, 91,885 cases of incident diabetes occurred. In multivariable analysis, the risk of incident diabetes was significantly higher in the NAFLD group than the control group (adjusted hazard ratio = 4.97, 95% confidence interval, 4.90–5.05). Stratified analyses showed higher associations in those who were ≥30 years, male, obese, smokers, alcohol consumers, and did not regularly exercise (all P Conclusions NAFLD is associated with a five-fold increased risk of incident diabetes in young adults. These results suggest an independent high risk for incident diabetes in young adults and underscore the importance of paying early attention to patients who develop NAFLD before middle age.

We aimed to examine whether metabolic syndrome (MetS) is associated with mobility in the older adults, using the timed up and go (TUG) test which is one of the most widely used tests for evaluating mobility. This is population-based study with the National Health Insurance Service–National Health Screening Cohort database of National Health Information Database. Participants included were those who completed the TUG as part of the National Screening Program for Transitional Ages. An abnormal TUG result was defined as a time ≥ 10 s. Multiple logistic regression models were used to assess the associations between MetS and TUG results. We constructed three models with different levels of adjustment. Furthermore, we conducted a stratified analysis according to the risk. Among the 40,767 participants included, 19,831 (48.6%) were women. Mean TUG value was 8.34 ± 3.07 s, and abnormal TUG test results were observed in 4,391 (10.8%) participants; 6,888 (16.9%) participants were categorised to have MetS. The worst TUG test results were obtained in participants with three or four MetS features, and a J-shaped relationship of each MetS feature, except triglyceride (TG) and high-density lipoprotein-cholesterol (HDL-C), with TUG test was found. Participants with MetS had 18% higher likelihood of showing abnormal TUG test results in a fully adjusted model (adjusted odds ratio 1.183, 95% confidence interval 1.115–1.254). The stratified analysis revealed that participants with central obesity, high blood pressure, and normal HDL-C and TG were more likely to have abnormal TUG times. Participants with MetS had a higher risk of exhibiting abnormal TUG results, and except for HDL-C and TG, all other MetS features had a J-shaped relationship with TUG. Preventive lifestyle such as lower carbohydrate and higher protein intake, and endurance exercise is needed.

Objective Conditional relative survival (CRS) considers changes in prognosis over time and may offer more useful estimates for survivors. We aimed to investigate CRS among patients with cervical cancer stratified by various factors that influence survival probability. Methods This nationwide retrospective study used data from the Korean Central Cancer Registry. We included 78,606 patients diagnosed with cervical cancer as their first cancer between January 1, 1996 and December 31, 2015, and who were followed until December 31, 2016. CRS and the conditional probabilities of death for the following 1 year were stratified by age at diagnosis, histology, cancer stage, treatment, year of diagnosis, and social deprivation index. Results The 5-year relative survival rate at the time of diagnosis was 80.6% for all cases. The probability of surviving an additional 5 years conditioned on having already survived 1, 2, 3, 4, and 5 years after diagnosis was 85.7%, 90.6%, 93.5%, 95.3%, and 94.3%, respectively. Patients with poorer initial survival estimates (older, advanced stage, non-squamous cell histology) generally showed the largest increases in CRS over time. Patients aged ≥70 years had the highest probability of death in the first year after diagnosis (24.5%), but the conditional probability of death in the 2nd, 3rd, 4th, and 5th years declined abruptly to 13.1%, 7.5%, 5.4%, and 3.9%, respectively. Conclusions The CRS rates for patients with cervical cancer improved over time, particularly among patients with poorer initial prognoses. Our estimates enable patients to make better informed decisions regarding follow-up care and their personal life.

Key Points Question Are female reproductive factors associated with bone health in postmenopausal women? Findings In this population-based cohort study of 1 272 115 postmenopausal Korean women, later menarche, earlier menopause, and shorter reproductive span were each independently associated with increased risk of fracture. Meaning This study’s findings suggest that female reproductive factors are independent risk factors for fracture incidence, with a higher risk associated with shorter lifetime endogenous estrogen exposure., Importance Although estrogen level is positively associated with bone mineral density, there are limited data on the risk of fractures after menopause. Objective To investigate whether female reproductive factors are associated with fractures among postmenopausal women. Design, Setting, and Participants This population-based retrospective cohort study used data from the Korean National Health Insurance Service database on 1 272 115 postmenopausal women without previous fracture who underwent both cardiovascular and breast and/or cervical cancer screening from January 1 to December 31, 2009. Outcome data were obtained through December 31, 2018. Exposures Information was obtained about reproductive factors (age at menarche, age at menopause, parity, breastfeeding, and exogenous hormone use) by self-administered questionnaire. Main Outcomes and Measures Incidence of any fractures and site-specific fractures (vertebral, hip, and others). Results Among the 1 272 115 participants, mean (SD) age was 61.0 (8.1) years. Compared with earlier age at menarche (≤12 years), later age at menarche (≥17 years) was associated with a higher risk of any fracture (adjusted hazard ratio [aHR], 1.24; 95% CI, 1.17-1.31) and vertebral fracture (aHR, 1.42; 95% CI, 1.28-1.58). Compared with earlier age at menopause (, This cohort study uses data from the Korean National Health Insurance System database to investigate whether female reproductive factors are associated with fractures among postmenopausal women in Korea.

In previous literature regarding development of rheumatoid arthritis (RA), female reproductive factors have been described as protective factors, risk factors, or irrelevant, leading to inconsistent results. The aim of this study was to investigate the effect of female reproductive factors on the incidence of seropositive RA. A large population-based retrospective cohort of the National Health Insurance Service data in South Korea was used. Postmenopausal women who participated in both cardiovascular and breast cancer screening in 2009 were included and followed until date of seropositive RA diagnosis, death, or December 31, 2018. Multivariable-adjusted Cox proportional hazards model was used to assess the association between reproductive factors and incident seropositive RA. Of 1,357,736 postmenopausal women, 6056 women were diagnosed with seropositive RA, and the incidence rate was 54.16 cases/100,000 person-years. Reproductive factors other than hormone replacement therapy (HRT) were not significantly associated with seropositive RA incidence. Postmenopausal women who used HRT ≥ 5 years were associated with a higher aHR of incident seropositive RA than never-users (aHR 1.25; 95% CI 1.09–1.44). Alcohol consumption less than 30 g per day (aHR 0.80; 95% CI 0.74–0.87), regular physical activity (aHR 0.90; 95% CI 0.84–0.97), diabetes mellitus (aHR 0.85; 95% CI 0.78–0.93), and cancer (aHR 0.77; 95% CI 0.64–0.92) were associated with lower risk of seropositive RA. Most female reproductive factors did not significantly affect the development of seropositive RA in postmenopausal women. Only HRT is associated with a small but significant increase in risk of seropositive RA.

Background Over 10% of adults aged ≥65 years have anemia, as defined by the World Health Organization (WHO). As the timed up and go (TUG) test is one of the most widely used tests of mobility, this study investigated whether anemia was associated with mobility capacity assessed using the TUG test in older adults. Methods Subjects belonging to the Korean National Health Insurance Service-National Health Screening Cohort of the National Health Information Database were reviewed. Subjects were included if they had completed the TUG test as part of the National Screening Program for Transitional Ages in Korea. An abnormal TUG test result was defined as a time of ≥10 s and anemia was defined according to the WHO criteria as a hemoglobin (Hb) concentration of Results The 81,473 subjects included 41,063 (50.4%) women and 40,410 (49.6%) men. Mean TUG time was 8.44 ± 3.08 s, and abnormal TUG test results were observed in 22,138 (27.2%) subjects. Mean Hb concentration was 13.72 ± 1.41 g/dL, and 10,237 (12.6%) subjects had anemia. U-shaped associations between Hb concentration and TUG test results were observed in both sexes. Subjects with anemia were 19% more likely to have abnormal TUG test results, according to the fully adjusted model (adjusted odds ratio: 1.192, 95% confidence interval: 1.137–1.247). Similar results were observed for both sexes. Stratified analysis showed that subjects with anemia were more likely to have abnormal TUG test results regardless of risk factors. Conclusions Individuals with anemia are more likely to have abnormal TUG test results, regardless of risk factors, than individuals without anemia. U-shaped relationships between Hb concentrations and TUG test results were observed in both sexes, although the optimal Hb concentration differed between men and women.

To examine the association between obesity measured by body mass index (BMI) and waist circumference (WC) according to menopausal status in Korean women.We identified 6,467,388 women, using the Korean National Health Insurance System Cohort. Cox-proportional hazard models were used to generate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for breast cancer risk in relation to BMI and WC.In postmenopausal women, the risk of breast cancer increased with BMI. Compared to women with a BMI of 18.5-23 kg/m two, the risk of invasive breast cancer was lower in patients with BMI 18.5 (aHR 0.82, 95% CI 0.75-0.89), while it increased linearly in those with BMI 23-25 (1.11, 1.08-1.14), BMI 25-30 (1.28, 1.25-1.32), and BMI ≥ 30 (1.54,1.47-1.62). In contrast, the risk of breast cancer decreased with BMI in premenopausal women. Compared to women with a BMI of 18.5-23, the risk of IBC was similar in those with a BMI 18.5 (1.02, 0.94-1.11) and BMI 23-25 (1.01, 0.97-1.05), but was significantly lower in those with a BMI 25-30 (0.95, 0.91-0.98) and BMI ≥ 30 (0.90, 0.82-0.98). A relative increase with BMI was less profound for carcinoma in situ in postmenopausal women, and a relative decrease was more profound in premenopausal women. An analysis using WC showed almost identical results.There was a positive relationship between obesity and breast cancer in postmenopausal women, and an inverse association in premenopausal women.

Introduction Previous evidence has suggested roles for α-synuclein propagation and vitamin B12 (VitB12) deficiency in the pathogenesis of Parkinson's disease (PD). We investigated whether gastric cancer (GC) patients who underwent gastrectomy had a lower risk of PD and whether VitB12 supplementation modified the risk. Methods GC patients aged ≥50 years who underwent curative gastrectomy between 2007 and 2012 (n = 72,216) and matched comparison groups (n = 211,389) were identified from the Korean National Health Insurance database. The risks of PD were analyzed by Cox regression. Results Compared to their matched comparison groups, GC patients who underwent gastrectomy showed a decreased risk of PD (adjusted HR [aHR] 0.86; 95% confidence interval [CI] 0.75–0.98), but the significance disappeared after further adjustment with smoking and body mass index (BMI). To elaborate, subtotal gastrectomy (STG) was associated with decreased risk of PD (aHR 0.85; 95% CI 0.74–0.99) while total gastrectomy (TG) was not (aHR 0.89; 95% CI 0.66–1.19), although the risk reduction was not significant when further adjusted for smoking and BMI. Among the patients who underwent TG, their risk of PD was markedly lower when they had VitB12 supplementation after surgery (aHR 0.36; 95% CI 0.17–0.76), while the risk was higher when they did not have any (aHR 1.55; 95% CI 1.03–2.32). Conclusions GC patients who underwent gastrectomy and received uninterrupted VitB12 supplementation had a decreased incidence of PD. This study provides indirect epidemiological evidence for the potential roles of gastrectomy and VitB12 in the pathogenesis of PD.

Chronic kidney disease in its later stages is associated with increased risk of kidney cancer. We investigated whether chronic kidney disease at milder stages is associated with increased kidney cancer risk, using a retrospectively selected cohort of 9,809,317 adults in the Republic of Korea who participated in a nationwide health screening (2009–2016). We examined the impact of estimated glomerular filtration rate (eGFR), dipstick proteinuria, and interactive associations between the 2 factors on the risk of incident kidney cancer. During a median follow-up period of 7.3 years, 10,634 kidney cancers were identified. After adjustment for multiple confounders, participants with a reduced eGFR had an increased risk of kidney cancer (for eGFR

Purpose The purpose of this study was to compare health-related quality of life (HRQoL) of disease-free prostate (PC), kidney (KC), and bladder cancer (BC) survivors with that of the general population. Materials and Methods Our study included 331 urological cancer (UC) survivors (114 PC, 108 KC, and 109 BC) aged ≥ 50 years disease-free for at least 1 year after surgery. The control group included 1,177 subjects without a history of cancer. The HRQoL was assessed using the European Organization for Research and Treatment of Cancer QLQ-C30, the Duke-UNC Functional Social Support Questionnaire, and the Patient Health Questionnaire-9. Results There was no significant difference between the groups in terms of any of the functioning sub-scales and symptoms, except significantly lower social functioning observed in BC survivors than that observed in KC survivors. Although the three groups of UC survivors showed essentially similar functioning sub-scales and symptoms when compared to the general population, PC and BC survivors showed significantly lower social functioning and a lower appetite than that observed in controls. KC survivors showed lower physical functioning, as well as higher pain and dyspnea. Although all three groups of UC survivors reported higher financial difficulties, they also reported higher perceived social support than that reported by the non-cancer control group. No statistically significant difference was observed in terms of depressive symptoms between each group of UC survivors and the general population. Conclusion Disease-free survivors of the three major types of UCs showed generally similar HRQoL compared to the general population, as well as compared to each other.