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Introduction: There are several methods that are used to predict emergency room visits or rehospitalization for the elderly. However, existing risk assessment models of mortality in elderly people are limited. The purpose of this study was to ascertain the factors that affect all-cause mortality and to show the risk assessment model of mortality in elderly Koreans.Methods: This was a cohort study conducted using the health checkup data of 246,422 individuals aged ≥60 years, which was provided by the National Health Insurance Service of South Korea between January 1, 2009, and December 31, 2012. The hazard ratios and 95% confidence intervals (CIs) of several conditions and all-cause deaths were estimated using a multivariable Cox proportional hazards model. A nomogram was constructed to visualize the risk factors of mortality; a calibration plot and area under the curve (AUC) were also used to verify the nomogram.Results: Being 85 years or older (100 points) had the greatest influence on all-cause mortality, followed by being underweight (57 points), having more than five chronic diseases (49 points), and ages 78-84 years (45 points); smoking and lack of regular exercise affected mortality to a similar degree. The calibration curves showed good agreement between predictions and observations. The AUC of our nomogram was 0.73 (95% CI: 0.72-0.73).Conclusions: Our results showed the relationship between each condition and mortality rate among elderly individuals in Korea. Our nomogram showed a satisfactory performance in the assessment of the risk of all-cause mortality in elderly Korean people. [ABSTRACT FROM AUTHOR]

2‐Pyrones with a chiral branched allylic silyl ether substituent underwent intramolecular Diels–Alder reactions with remarkably high π‐facial‐ and endo‐selectivities. The resulting diastereomerically and enantiomerically pure cycloadducts were transformed into the natural products (+)‐lycopladine A and (−)‐lycoposerramine R. [ABSTRACT FROM AUTHOR]

2‐Pyrones with a chiral branched allylic silyl ether substituent underwent intramolecular Diels–Alder reactions with remarkably high π‐facial‐ and endo‐selectivities. The resulting diastereomerically and enantiomerically pure cycloadducts were transformed into the natural products (+)‐lycopladine A and (−)‐lycoposerramine R. [ABSTRACT FROM AUTHOR]

Behçet's disease (BD) is a chronic inflammatory disease. Low levels of plasma high-density lipoprotein cholesterol (HDL-C) are associated with Crohn's disease, another chronic inflammatory disease. However, the effects of low HDL-C levels on BD are unclear. We investigated the effects of HDL-C levels, and variability therein, on the risk for BD. We used the Korean National Health Insurance System database to identify 5,587,754 adults without a history of BD who underwent ≥ 3 medical examinations between 2010 and 2013. Mean HDL-C levels at each visit were used to calculate variability independent of the mean (VIM) and the coefficient of variation (CV). There were 676 new cases of BD (0.012%). The risk for BD was increased in participants with highly variable and low mean HDL-C levels. In a multivariate-adjusted model, the hazard ratios (95% confidence intervals) for BD incidence were 1.335 (1.058–1.684) in a high mean/high VIM group, 1.527 (1.211–1.925) in a low mean/low VIM group, and 2.096 (1.67–2.63) in a low mean/high VIM group compared to a high mean/low VIM group. Low mean HDL-C levels, and high variability therein, are independent risk factors for BD. [ABSTRACT FROM AUTHOR]

The impact of obesity could differ according to menopausal status since women undergo significant physiologic and metabolic changes due to menopause. We investigated the association between various major obesity indicators and the risk of impaired fasting glucose (IFG) according to menopausal status using nationally representative data. A total of 571,286 premenopausal and 519,561 postmenopausal women who underwent both Korean National Health Insurance Service (NHIS) cancer screening in 2009 and health check-ups in 2017 were analyzed. Multivariate logistic regression analyses were used to assess the effect of independent variables of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) in 2009, on dependent variable IFG in 2017. After adjusting for potential confounders, the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of developing IFG were analyzed. In the premenopausal group, the OR of obese BMI (≥25 kg/m2, <30 kg/m2) women was increased to 2.228 (95% CI: 2.139–2.321) compared to the normal BMI (≥18.5, <23 kg/m2) women as a reference. In the postmenopausal group, there was also a higher OR of 1.778 (95% CI: 1.715–1.843) in the obese BMI women compared to the normal group. A similar association of increasing ORs for IFG was shown in both groups when stratified by WC and WHtR. This nationwide study revealed that obesity and abdominal obesity, defined by various obesity indicators, consistently increased odds of acquiring IFG after 8 years in both pre- and postmenopausal groups, with the association being more robust in the premenopausal group. Our findings suggest that weight management and lifestyle modification may require more attention in premenopausal women. [ABSTRACT FROM AUTHOR]

Fatty liver index (FLI) is a simple and useful index that evaluates non-alcoholic fatty liver disease (NAFLD), particularly in large epidemiologic studies. Heart failure (HF) is becoming a burden to public health as the global trend toward an aging society continues. Thus, we investigated the effect of FLI on the incidence of HF using large cohort data from the Korean National Health Insurance health database. Methods and Results: A total of 7,958,538 subjects aged over 19 years without baseline HF (men = 4,142,264 and women = 3,816,274) were included. Anthropometric and biochemical measurements were evaluated. FLI scores were calculated and FLI ≥ 60 was considered as having NAFLD. Hazard ratios (HRs) and 95% confidence intervals (CIs) for HF incidence were analysed using multivariable time-dependent Cox proportional hazard models. During a mean follow up of 8.26 years, 17,104 participants developed HF. The FLI components associated with the incidence of HF and FLI showed a causal relationship with HF; the FLI ≥ 60 group had a higher HR for HF (HR 1.493; 95% CIs 1.41–1.581) than the FLI < 30 group. Subgroup analysis showed that fatty liver (FLI ≥ 60) with age ≥ 65 years or women displayed higher HR for HF than fatty liver with age < 65 or men, respectively. An increase in FLI score significantly increased the HR for HF except for those with a FLI score change from <30 to 30–60. Conclusion: NAFLD defined by FLI and increase in FLI score were associated with the incidence of HF. Further detailed prospective studies are needed. [ABSTRACT FROM AUTHOR]

Background: No epidemiologic study has previously reported on the associations among Behçet's disease (BD) and autoimmune disorders. Objectives: To investigate the association between BD and the autoimmune disorders multiple sclerosis and rheumatoid arthritis. Methods: Medical records of patients newly diagnosed with BD (n = 6,214) in 2012–2017 were analyzed using data entered into a large, nationwide database from 2007 to 2017. An age- and sex-matched control population of individuals without BD was sampled at a ratio of controls:BD cases of 3:1 (n = 18,642). Both cohorts were analyzed for the presence of multiple sclerosis or rheumatoid arthritis within a minimum of 5 years prior to their BD diagnosis. Results: Patients with BD had significantly higher odds ratios (ORs) for multiple sclerosis (8.85 [95% CI 2.36–33.17]) and rheumatoid arthritis (4.62 [95% CI 3.35–6.35]) than the control group after adjustment for diabetes mellitus, hypertension, and dyslipidemia. BD patients aged <40 years had a higher proportion of rheumatoid arthritis (OR 23.91, 95% CI 5.50–103.9) than older patients (OR 3.96, 95% CI 2.83–5.54). Conclusion: Our results suggest that BD is associated with multiple sclerosis and rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

Background and purpose: Although body weight variability has been associated with mortality, cardiovascular disease, and dementia, the relationship between body weight variability and Parkinson disease (PD) has rarely been studied. We aimed to investigate the longitudinal association between body weight variability and PD incidence. Methods: A nationwide population‐based, cohort study was conducted using the database from the Health Insurance Review and Assessment Service of the whole Korean population. We analyzed 2,815,135 participants (≥40 years old, mean age = 51.7 ± 8.6 years, 66.8% men) without a previous PD diagnosis. We determined individual body weight variability from baseline weight and follow‐up visits. We used Cox proportional hazards regression models. Results: The highest quartile group was associated with increased PD incidence compared with the lowest quartile group after adjustment for confounding factors (hazard ratio [HR] = 1.18, 95% confidence interval [CI] = 1.08–1.29). In contrast, baseline body mass index, baseline waist circumference, and waist circumference variability were not associated with increased PD incidence. In the body weight loss group, individuals within the quartile of the highest variation in body weight showed a higher HR of PD risk than those within other quartiles (HR = 1.41, 95% CI = 1.18–1.68). Conclusions: Body weight variability, especially weight loss, was associated with higher PD incidence. This finding has important implications for clinicians and supports the need for preventative measures and surveillance for PD in individuals with fluctuating body weight. [ABSTRACT FROM AUTHOR]

Little is known about the comorbidities in actinic keratosis patients. To evaluate the association of actinic keratosis with certain malignancies. All patients with actinic keratosis (n = 61,438) and age- and sex-matched control subjects (n = 307,190) at a 5:1 ratio were enrolled using data from the Korean National Health Insurance Service between the years 2007 and 2014. In subjects with actinic keratosis, overall cancer incidence was higher than that for controls after income level, habitat, diabetes, hypertension, and dyslipidemia were adjusted (Hazard Ratio [HR] = 1.43 [95% confidence interval 1.38–1.47]). The positive association of specific cancers were observed in the following order: skin cancer (HR = 3.43 [2.47–4.75]), oral cavity and pharyngeal cancer (HR = 1.99 [1.57–2.52]), lymphoma (HR = 1.59 [1.28–1.96]), leukemia (HR = 1.35 [1.03–1.77]), prostate cancer (HR = 1.35 [1.21–1.51]), renal cancer (HR = 1.29 [1.02–1.63]), liver cancer (HR = 1.21 [1.09–1.35]), thyroid cancer (HR = 1.20 [1.05–1.38]), and gastric cancer (HR = 1.13 [1.03–1.23]). Although further research on pathologic mechanism is needed, the implications of a positive correlation between actinic keratosis and internal organ malignancies has great significance. [ABSTRACT FROM AUTHOR]

Background: The longitudinal association between dynamic changes in the metabolic syndrome (MS) status and Parkinson's disease (PD) has been poorly studied. Objective: We examined whether dynamic changes in MS status are associated with altered risk for PD. Methods: This study was a nationwide retrospective cohort study. We enrolled 5,522,813 individuals aged≥40 years who had undergone health examinations under the National Health Insurance Service between 2009 and 2010 (two health examinations with a 2-year interval). Participants were followed up until the end of 2017. The participants were categorized into four groups according to MS status changes over 2 years: non-MS, improved MS, incident MS, and persistent MS groups. Multivariable Cox hazard regression was performed. Results: During the 7-year median follow-up, there were 20,524 cases of newly developed PD. Compared with non-MS group, improved, incident, and persistent MS groups for 2 years were significantly associated with higher risks of PD (model 3; hazard ratio: 1.12, 95%confidence interval: 1.06–1.19 [improved MS]; 1.15, 1.09–1.22 [incident MS]; and 1.25, 1.20–1.30 [persistent MS]). Individuals with incident and persistent abdominal obesity, low levels of high-density lipoprotein cholesterol, hypertriglyceridemia, and hyperglycemia had a significantly increased risks of PD compared with those without either condition over 2 years. Conclusion: Persistent and incident MS and its components may be risk factors for incident PD. Ever exposure to MS may also be associated with PD risk. Appropriate intervention for preventing and improving MS may be crucial in decreasing the PD incidence. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the association between periodontitis and risk of incident Parkinson's disease using large-scale cohort data on the entire population of South Korea. Health checkup data from 6,856,180 participants aged 40 and older were provided by the National Health Insurance Service of South Korea between January 1, 2009, and December 31, 2009, and the data were followed until December 31, 2017. The hazard ratio (HR) of Parkinson's disease and 95% confidence interval (CI) were estimated using a Cox proportional hazards model adjusted for potential confounders. The incidence probability of Parkinson's disease was positively correlated with the presence of periodontitis. The HR of Parkinson's disease for the participants without the need of further dentist visits was 0.96 (95% CI 0.921–1.002); the HR of Parkinson's disease increased to 1.142 (95% CI 1.094–1.193) for the individuals who needed further dentist visits. Compared to individuals without periodontitis and without metabolic syndrome, the HR of incident Parkinson's disease gradually increased for individuals with periodontitis, with metabolic syndrome, and with both periodontitis and metabolic syndrome. People with periodontitis and metabolic syndrome had the highest HR of incident Parkinson's disease, at 1.167 (95% CI 1.118–1.219). In conclusion, a weak association between periodontitis and Parkinson's disease was suggested after adjusting for confounding factors from the population-based large-scale cohort of the entire South Korean population. [ABSTRACT FROM AUTHOR]

To examine the effect of socioeconomic status (SES) as measured by three components of education level, income level, and occupation on prevalence and symptom severity of knee osteoarthritis (OA) and to determine which of these factors has the strongest association. We conducted a cross-sectional study using data from the Fifth Korean National Health and Nutrition Examination Survey that were collected between 2010 and 2012. Male and female participants 50 years or older were included. Analyses to examine the associations of the three SES components with prevalence and symptom severity of knee OA were performed. A total 9,071 participants was included in the study. As expected, lower education, lower income level, and non-managerial or no job were associated with higher prevalence of knee OA and knee symptoms. Among the three SES components, lower education was most strongly associated with knee pain and radiographic knee OA after adjusting for the other two. Lower education level is the component of SES that most strongly relates to higher prevalence of knee OA and knee symptoms. Improving societal education level might decrease the socioeconomic burden of knee OA. [ABSTRACT FROM AUTHOR]

Metabolic syndrome (MetS) is characterized by insulin resistance, high blood pressure/sugar, dyslipidemia, and obesity. Whether MetS and its components affect the development of Behçet's disease (BD) remains unclear. This study was performed to investigate the associations between metabolic syndrome and risk of BD using nationwide population data. We conducted a retrospective cohort study of 10 505 818 Korean subjects who received health checkups in 2009–2012. Patients were classified into a MetS and its components group and were followed‐up until 2016 for new‐onset BD. A Cox proportional hazards model was used to assess the independent or synergistic effects of MetS and its components on the risk of incident BD. Compared to subjects without MetS components, the hazard ratio (HR) for development of BD in patients with MetS was 0.874 (95% confidence interval [CI]: 0.819–0.933) and this association was more prominent when all components of MetS were present (HR = 0.675, 95% CI = 0.571–0.798). Subjects with low high density lipoprotein (HDL) has a significantly increased risk of the development of BD (HR = 1.51, 95% CI = 1.4–1.594) compared to controls. This study showed that the incidence of Behçet's disease was reduced in subjects with MetS. Moreover, the presence of MetS components, with the exception of HDL, was negatively related to the development of BD. [ABSTRACT FROM AUTHOR]

We studied the association between living alone and the risk of incident type 2 diabetes in middle-aged individuals using nationwide cohort data from the Korean population. 11,686, 677 middle-aged individuals aged 40–64 years who underwent health examinations by the Korean National Health Insurance System between 2009 and 2012 were followed up until December 31, 2015. The hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox proportional hazards regression analysis. During the median follow-up duration of 5.6 years, 393,438 individuals developed type 2 diabetes. Living alone was significantly associated with incident type 2 diabetes in all adjusted models (HR 1.08; 95% CI 1.07–1.09 in model 4). Individuals who lived alone for < 1 year and 1–7 years were associated with increased HRs of 1.07 (1.04–1.09) and 1.08 (1.07–1.09). Living alone was associated with incident type 2 diabetes in all subgroups. The association was stronger in men than in women and younger individuals than in older individuals. Living alone, even for a short duration, may be an important factor in type 2 diabetes development. Better household conditions and appropriate support to one-person households may be needed to prevent type 2 diabetes. [ABSTRACT FROM AUTHOR]

Background and Aim: We investigated the relationship of BMI and waist circumference with the risk of colorectal cancer (CRC) using a population‐based cohort database and to explore the relationship of CRC with diabetes status. Methods: Retrospective data (age >20 years) on anthropometric variables, blood parameters of fasting sugar, lipid levels, and blood pressure were collected from the National Health Insurance Corporation database between 2009 and 2012. Cox regression models were used to estimate hazard ratio (HR) and corresponding 95% confidence intervals (95% CI). Results: Of the 23 121 360 people studied, 120 579 were diagnosed with CRC after a median follow‐up period of 5.4 years. Both waist circumference and body mass index were positively associated with increased risk of CRC, regardless of age or sex. After mutual adjustment, only waist circumference was significantly associated with increased risk of CRC (HR = 1.275, 95% CI: 1.205–1.349). When the risk of CRC was compared according to diabetes status among people with the same waist circumference range, risk of CRC was higher for those with worse diabetes status. Conclusion: When waist circumference and body mass index were mutually adjusted, only waist circumference was associated with CRC risk. In addition, the risk of CRC is gradually higher in those with worsening diabetes, even if their waist circumferences are within the same range. [ABSTRACT FROM AUTHOR]

In a previous study, we found that higher waist circumference (WC) and higher body mass index (BMI) both increase the risk of chronic spontaneous urticaria (CSU). The aim of this study was to determine whether WC and BMI also increase the duration of CSU. We used multivariable Cox proportional hazards models to determine the hazard ratio (HR) for longer disease duration (longer than 3 years) according to WC and BMI. A total of 52,667 subjects were enrolled and their mean age was 54.5. After adjustments for other confounding variables the high WC/high BMI group had 1.062 times higher HR (95% CI, 1.028–1.098) than the normal WC/normal BMI group. Interestingly, the high WC/normal BMI group showed a significantly higher HR (1.053; 95% CI, 1.008–1.101) than the normal WC/normal BMI group, but not the normal WC/high BMI group (0.998; 95% CI, 0.951–1.046). Taken together, our results suggest that high WC rather than high BMI is a predictive risk factor for the longer disease duration of CSU. [ABSTRACT FROM AUTHOR]

Aims/Introduction: We investigated the risk of incident type 2 diabetes according to the cumulative exposure to obesity or metabolic syndrome (MetS) during annual or biennial health examinations. Materials and Methods: The Korean National Health Insurance Service datasets from 2002 to 2017 were used for this retrospective longitudinal study. The risk for type 2 diabetes was analyzed according to the cumulative exposure to obesity and MetS among individuals who underwent four health examinations from 2009 to 2012 or 2013 (n = 2,851,745). Results: During examinations, 28.56 and 17.86% of the total participants showed fluctuations in metabolic health state and obesity, respectively. During a mean 5.01 years of follow up, 98,950 new type 2 diabetes cases developed. The risk for type 2 diabetes increased with the increase in exposure to MetS (hazard ratio [HR] 2.92, 95% confidence interval [CI] 2.86–2.99; HR 4.96, 95% CI 4.85–5.08; HR 7.46, 95% CI 7.30–7.63; HR 12.24, 95% CI 12.00–12.49 in groups with number of exposures one to four, respectively) and obesity (HR 1.60, 95% CI 1.56–1.65; HR 1.87, 95% CI 1.81–1.92; HR 2.25, 95% CI 2.19–2.31; HR 3.46, 95% CI 3.41–3.51 in groups with number of exposures one to four, respectively), showing a more detrimental effect of cumulative exposure to MetS, when compared with the exposure to obesity. Conclusions: Metabolic health and obesity fluctuated within a relatively short period of 4–5 years. Although the impact was much greater for MetS than for obesity, the cumulative duration of both obesity and MetS was associated with an increased risk of type 2 diabetes in a dose‐response manner. Therefore, continuously maintaining metabolic health and normal weight is crucial to prevent incident type 2 diabetes. [ABSTRACT FROM AUTHOR]

Background. Little information is available on the association between parents' metabolic syndrome (MetS) and adolescent offspring's obesity in Korea. The aim of our study is to determine the association between parent's metabolic syndrome and offspring's obesity. Methods. The study data were obtained from the Korean National Health and Nutrition Examination Survey conducted during 2009–2016. In the present study, 3140 adolescents aged 12 to 18 years, their paternal pairs (PP, fathers = 2244), and maternal pairs (MP, mothers = 3022) were analyzed. Of these 3140 adolescents, 2637 had normal weight {age- and sex-specific body mass index (BMI) under the 85th percentile}, whereas 467 were overweight (age- and sex-specific BMI over the 85th percentile). Results. Offspring's overweight and central obesity were associated with all components of the PP's metabolic risk factors, including central obesity (p < 0.001), systolic (p < 0.001) and diastolic blood pressure (p < 0.001), glucose intolerance (p < 0.001), and triglyceride (p < 0.002) and high-density lipoprotein levels (p = 0.049). In addition, offspring's overweight and central obesity were also associated with the metabolic risk factors of MP, including central obesity (p < 0.001), systolic (p < 0.001) and diastolic blood pressure (p < 0.001), glucose intolerance (p < 0.001), and triglyceride levels (p < 0.001). In multivariate logistic regression analysis, offspring's overweight was significantly and positively associated with parental central obesity (PP, adjusted odds ratio (OR) = 1.593; 95% confidence interval (CI): 1.192–2.128; MP, adjusted OR = 2.221, 95% CI: 1.755–2.812) and parental metabolic syndrome (PP, adjusted OR = 2.032; 95% CI: 1.451–2.846; MP, adjusted OR = 2.972, 95% CI: 2.239–3.964). As the number of parental metabolic risk factors increased, offspring's risk for overweight and central obesity increased (p for trends < 0.001). Conclusion. Parental metabolic syndrome was associated with obesity in 12- to 18-year-old offspring in Korea. [ABSTRACT FROM AUTHOR]

Objectives: Variability in various biomarkers has emerged as a new clinical indicator for diseases including neurodegenerative disorders. Gamma-glutamyl transferase (GGT) has a potential to be involved in the pathogenesis of dementia due to its function as a marker of oxidative stress and atherosclerosis. We investigated the association between baseline GGT, GGT variability, and dementia risk for the first time in a large population.Methods: The Korean National Health Insurance Service datasets of claims and preventive health check-ups from 2004 to 2016 were used for this retrospective longitudinal study. The risk of incident dementia (all-cause dementia, Alzheimer's disease, and vascular dementia) was analyzed according to sex-specific quartiles of baseline GGT and GGT variability, and groups categorized by baseline GGT and GGT variability in ≥40-year-old individuals without baseline dementia (N = 6 046 442; mean follow-up 6.32 years).Results: During follow-up, 166 851 cases of new dementia developed. The fully adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia increased in the higher quartiles of baseline GGT and GGT variability (HR [95% CI]: Q2, 1.034 [1.019-1.049]; Q3, 1.090 [1.075-1.105]; Q4, 1.212 [1.196-1.229]). The association between GGT variability quartiles and dementia risk remained significant even after adjusting for log-transformed baseline GGT level. The fully adjusted HRs for dementia was highest in the group with high baseline GGT concentration and the highest GGT variability quartile [HR (95% CI): 1.273 (1.250-1.296)].Conclusions: Not only baseline GGT level, but also GGT variability may be an independent predictor of dementia, and might be used for risk stratification for future dementia. [ABSTRACT FROM AUTHOR]

Background: The association of metabolic syndrome and its components with the risk of thyroid cancer is unclear. Thus, we conducted a large-scale, nationwide, population-based, cohort study to investigate this relationship. Methods: We studied 9,890,917 adults without thyroid cancer from the Korean National Health Insurance health checkup database from January 1 to December 31, 2009. Individuals with at least three of the following five components were diagnosed with metabolic syndrome: abdominal obesity, hypertriglyceridemia, low high-density lipoprotein-cholesterol levels, elevated blood pressure, and hyperglycemia. Multivariate Cox proportional hazards models were used to estimate thyroid cancer risk. Results: During the average 7.2 years of follow-up, 77,133 thyroid cancer cases were newly identified. The thyroid cancer risk was higher in the metabolic syndrome group than in the nonmetabolic syndrome group (hazard ratio [HR] 1.15 [95% confidence interval, CI 1.13–1.17]). The association between metabolic syndrome and thyroid cancer risk was significant in the obese group (HR 1.10 [CI 1.07–1.13]) and not in the nonobese group (HR 1.002 [CI 0.98–1.03]). The effect of metabolic syndrome on the risk of thyroid cancer differs according to obesity (p for interaction = 0.017). People with all five components of metabolic syndrome had a 39% higher risk than those without any components (HR 1.39 [CI 1.33–1.44]). The higher risk of thyroid cancer in people with all five components was significant in the obese group (HR 1.29 [CI 1.21–1.38]), but not in the nonobese group (HR 1.06 [CI 0.98–1.14]). There was a significant interaction between the number of metabolic syndrome components and obesity (p for interaction <0.0001). For the combined effect of obesity and metabolic syndrome on the risk of thyroid cancer, obese men with metabolic syndrome had the highest risk of thyroid cancer compared with those without (HR 1.58 [CI 1.52–1.64]), but obese women with metabolic syndrome did not. Conclusions: Metabolic syndrome was associated with an increased risk of thyroid cancer in the Korean general population. Metabolic syndrome had a more significant risk of thyroid cancer in the obese group. Metabolic syndrome and obesity were associated with a higher risk of thyroid cancer in men but not in women. [ABSTRACT FROM AUTHOR]

Objective: Obesity and type 2 diabetes are risk factors for cardiovascular diseases and mortality, and they commonly result in weight variabilities. We aimed to investigate the association between body weight variability and risk of major cardiovascular outcomes and mortality in individuals with type 2 diabetes using large-scale, nationwide cohort data on the Korean population.Research Design and Methods: We enrolled 624,237 individuals with type 2 diabetes who underwent health examinations provided by the Korean National Health Insurance System between 2009 and 2010, with three or more body weight measurements within 5 years since enrollment and followed up until the end of 2017. We assessed body weight variability using four indices, including variability independent of the mean (VIM). A multivariate-adjusted Cox proportional hazards regression analysis was performed.Results: During the follow-up, 15,832, 25,038, and 44,716 cases of myocardial infarction (MI), stroke, and all-cause mortality, respectively, were recorded. Body weight variability was associated with increased risks of major cardiovascular outcomes after adjusting for confounding variables. Compared with the hazard ratios (HRs) of the lowest quartile group, the HRs (95% CIs) of the highest quartile group of VIM for body weight were 1.15 (1.10-1.20), 1.22 (1.18-1.26), and 1.58 (1.53-1.62) for MI, stroke, and all-cause mortality, respectively.Conclusions: Body weight variability was associated with increased risks of MI, stroke, and all-cause mortality in patients with type 2 diabetes and may be a predictor of cardiovascular outcomes in such patients. Appropriate interventions to maintain stable weight could positively influence health outcomes in patients with type 2 diabetes. [ABSTRACT FROM AUTHOR]

Objective: Previous studies have suggested that diabetes increases the risk of Parkinson disease (PD); however, this has not been conclusively established. We analyzed the risk of PD based on baseline glucose tolerance status in a large-scale cohort representative of the general Korean population.Research Design and Methods: This analysis was performed in a cohort of 15,168,021 adults aged ≥40 years who underwent health checkups under the National Health Insurance Service between January 2009 and December 2010. The clinical course of subjects was monitored until December 2016. Subjects were classified into the following groups: no diabetes, impaired fasting glucose (IFG), diabetes duration <5 years, and diabetes duration ≥5 years. We analyzed the adjusted hazard ratio of PD for each group.Results: During the observation period of 49,076,148.74 person-years, PD occurred in 31,577 patients. Compared with the nondiabetes group, the adjusted hazard ratio was 1.038 (95% CI, 1.009-1.067) in the IFG group, 1.185 (95% CI, 1.143-1.229) in the diabetes duration <5 years group, and 1.618 (95% CI, 1.566-1.672) in the diabetes duration ≥5 years group. These results were consistent with those of the subgroup analysis, and the presence of diabetes further increased the risk of PD regardless of comorbidities such as cardiovascular, cerebrovascular, and chronic kidney diseases.Conclusions: This population-based cohort study suggests that diabetes is an independent risk factor for PD. [ABSTRACT FROM AUTHOR]

Smoking cessation reduces the cardiovascular risk but increases body weight. We investigated the risk of subsequent myocardial infarction and ischemic stroke according to weight gain after smoking cessation, using a nationwide population based cohort. We enrolled 3,797,572 Korean adults aged over 40 years who participated in national health screenings between 2009 and 2010. Subjects who quit smoking were classified into three subgroups according to the weight change between baseline and 4 years prior. Myocardial infarctions and ischemic strokes were followed until the end of 2015. We compared the hazard ratios among smoking cessation subgroups, non-smokers, and current smokers. The mean changes in weight (1.5 ± 3.9 kg) of the smoking cessation group were higher than those of the other groups (p < 0.0001). A total of 31,277 and 46,811 subjects were newly diagnosed with myocardial infarction and ischemic stroke, respectively. Regardless of weight change, all subgroups of smoking cessation had significantly less risk than current smokers. The subgroup of smoking cessation with weight gain over 4kg showed the lowest risk for myocardial infarctions (hazard ratio 0.646, 95% confidence interval 0.583–0.714, p < 0.0001) and ischemic strokes (hazard ratio 0.648, 95% confidence interval 0.591–0.71, p < 0.0001) after multivariable adjustment. In conclusion, weight gain after smoking cessation did not adversely affect the cardiovascular protective effect. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate whether GGT variability is able to predict the risk of end-stage renal disease (ESRD). The study subjects were Koreans who conducted health exams supported by the Korean National Health Insurance Corporation during 2009–2012 (baseline). After excluding individuals aged < 40 years, heavy alcoholics, or those with histories of chronic liver disease or ESRD, we followed 6,058,995 individuals. We calculated the average successive variability (ASV) of GGT values during the 5 years before the baseline as a parameter of variability. Using Cox proportional analyses, we evaluated the risk of ESRD according to GGT ASV quartiles, defined as the initiation of renal replacement therapy or kidney transplantation, or December 31, 2016. During 38,663,279.3 person-years of follow-up, 12,057 cases of ESRD were identified. Compared with GGT ASV quartile 1, the risk of ESRD was higher in ASV quartiles 3–4 and increased serially, even after adjustment for several metabolic parameters, baseline renal function, presence of comorbidities, low income, and baseline GGT and hemoglobin level. The fully adjusted hazard ratios (95% confidence intervals) of GGT ASV quartiles 3 and 4 were 1.06 (1.01–1.12) and 1.12 (1.06–1.18), respectively. In conclusion, GGT variability is a putative risk factor for ESRD in Koreans. [ABSTRACT FROM AUTHOR]

Background: We aimed to investigate the hazard of hospitalization for heart failure (hHF) according to the transitions in metabolic health and obesity status. Methods: The Korean National Health Insurance Service datasets from 2002 to 2017 were used for this nationwide, longitudinal, population-based study. The hazard of hHF was analyzed according to the eight groups stratified by stability in metabolic health and transition in obesity status among initially metabolically healthy adults who underwent two cycles of health examinations in 2009–2010 and 2013–2014 (N = 7,148,763). Results: During two examinations, 48.43% of the initially metabolically healthy obese (MHO) individuals and 20.94% of the initially metabolically healthy non-obese (MHNO) individuals showed changes in their metabolic health and obesity status. During a mean follow-up of 3.70 years, 3151 individuals were hospitalized for HF. When stable MHNO individuals were set as the reference, transition to metabolically unhealthy phenotype was associated with an increased hazard of hHF; the hazard ratio (HR) and 95% confidence interval (CI) in the individuals who transformed from MHO to metabolically unhealthy non-obese was 2.033 (1.579–2.616). The constant MHO group had a 17.3% increased hazard of hHF compared with the stable MHNO group [HR (95% CI) 1.173 (1.039–1.325)]. Individuals who shifted from MHO to MHNO showed a 34.3% lower hazard of hHF compared with those who maintained the MHO category [HR (95% CI) 0.657 (0.508–0.849)]. Conclusion: Dynamic changes in metabolic health and obesity status were observed during a relatively short interval of 3–5 years. Loss of metabolic health was significantly associated with an increased hazard of hHF. Even if metabolic health was maintained, persistent obesity remained as a risk factor for hHF, and transition from MHO to MHNO had a protective effect against hHF. Therefore, the prevention and control of obesity while maintaining metabolic health would be crucial in preventing hHF. [ABSTRACT FROM AUTHOR]

Objective: Behçet disease (BD) is a chronic inflammatory multiorgan disease. An increased risk of cardiovascular disease (CVD) and heightened death rate with BD have been suggested, but to our knowledge, a nationwide large-scale study has not been conducted to date. This study aimed to determine the overall CV risk and death rate in patients with BD versus controls using the Korean National Health Insurance Service claim database.Methods: Patients with BD (n = 5576) with no previous history of CVD were selected from 2010 to 2014. An age- and sex-matched control population of individuals without BD (n = 27,880) was randomly sampled at a ratio of 5:1. Both cohorts were followed for incident CVD or all-cause death until 2015.Results: The risks of myocardial infarction (HR 1.72, 95% CI 1.01-2.73) and stroke (HR 1.65, 95% CI 1.09-2.50) were significantly higher in patients with BD than in controls. Patients with BD also had a significantly higher risk of all-cause death (HR 1.82, 95% CI 1.40-2.37) compared to controls.Conclusion: Korean patients with BD had a higher overall risk of CVD than did those without BD. Therefore, patients with BD must be carefully monitored for the potential development of CVD to ensure that appropriate early treatments are delivered. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to evaluate the association between weight change and mortality in Korean older adults. Methods: We collected data pertaining to National Screening Program participants aged ≥65 years from the Korean National Health Insurance Corporation records during 2005–2011. To this data, we included mortality data, such as the date of death, of these patients (up to and including 2017) from Statistics Korea. We defined weight change as a difference in bodyweight measured in the National Screening Program over a period of 4 years. Cox proportional hazards models were used to evaluate the association between weight change and mortality. Results: The study population consisted of 1 100 256 participants, and a total of 46 415 deaths were observed during a mean follow‐up period of 3.2 ± 0.8 years (maximum 5.0 years). For 3 531 585 person‐year follow up, the mortality rate for stable weight was 10.79 per 1000 person‐years (PY). Weight loss increased the mortality rate by 68%, whereas weight gain increased the rate by 10% compared with stable weight (weight loss: mortality rate 20.28 per 1000 PY, adjusted hazard ratio 1.68, 95% confidence interval 1.65–1.72; weight gain: mortality rate 12.86 per 1000 PY, adjusted hazard ratio 1.10, 95% confidence interval 1.07–1.13). However, in subgroup analysis, for participants who were underweight at baseline, current cigarette smokers or heavy alcohol drinkers, weight gain did not increase the mortality rate. Conclusions: In Korean older adults, regardless of the risk factors, both weight loss and weight gain increased the mortality rate compared with stable weight. Geriatr Gerontol Int 2020; 20: 474–481. [ABSTRACT FROM AUTHOR]

Background: Exercise is known to be associated with health-related quality of life (HRQoL), however, evidence on the association between type of exercise and HRQoL in the general population is limited. We performed this study to investigate the association of exercise types and their combinations with HRQoL in Korean adults.Methods: We analyzed data from 13,437 adults aged ≥19 years without activity limitations who had participated in the 5th Korea National Health and Nutrition Examination Survey 2010-2012. As per the American College of Sports Medicine guideline, exercise types were categorized into eight groups: walking (W), flexibility (F), resistance (R), W + F, W + R, F + R, and W + F + R exercise groups and a non-exercise group. The European Quality of Life-5 Dimension (EQ-5D) index and the European Quality of Life Visual Analogue Scale (EQ-VAS) were used to assess HRQoL.Results: The mean age of participants was 42.8 ± 0.2 years. The proportion of participants in the non-exercise group was the highest (34.7%); among the exercise groups, the walking group was the most prevalent (16.9%) and the W + R group was the least (1.2%). In analysis of covariance, the mean EQ-5D index in W (0.875), W + F (0.878), F + R (0.877), and W + F + R (0.876) groups was significantly higher compared with that in non-exerciser group (0.869) (p < 0.05). The mean EQ-VAS score in the W (64.064), F (64.427), W + F (65.676), F + R (65.811), and W + F + R (67.110) groups was higher than that in the non-exercise group (62.396) (p < 0.05). No difference was observed between R and W + R groups and non-exercise group with regard to the EQ-5D index and EQ-VAS score.Conclusions: The W (for 30 min at least five times a week), W + F, F + R (at least two days a week), and W + F + R groups showed higher HRQoL than the non-exercise group. This study may be helpful in the development of public exercise interventions, which could help enhance HRQoL in adults. [ABSTRACT FROM AUTHOR]

Objective: There is a controversy over the association between obesity and end-stage renal disease (ESRD) in people with or without type 2 diabetes; therefore, we examined the effect of BMI on the risk of ESRD according to glycemic status in the Korean population.Research Design and Methods: The study monitored 9,969,848 participants who underwent a National Health Insurance Service health checkup in 2009 from baseline to the date of diagnosis of ESRD during a follow-up period of ∼8.2 years. Obesity was categorized by World Health Organization recommendations for Asian populations, and glycemic status was categorized into the following five groups: normal, impaired fasting glucose (IFG), newly diagnosed diabetes, diabetes <5 years, and diabetes ≥5 years.Results: Underweight was associated with a higher risk of ESRD in all participants after adjustment for all covariates. In the groups with IFG, newly diagnosed type 2 diabetes, diabetes duration <5 years, and diabetes ≥5 years, the hazard ratio (HR) of the underweight group increased with worsening glycemic status (HR 1.431 for IFG, 2.114 for newly diagnosed diabetes, 4.351 for diabetes <5 years, and 6.397 for diabetes ≥5 years), using normal weight with normal fasting glucose as a reference. The adjusted HRs for ESRD were also the highest in the sustained underweight group regardless of the presence of type 2 diabetes (HR 1.606 for nondiabetes and 2.14 for diabetes).Conclusions: Underweight showed more increased HR of ESRD according to glycemic status and diabetes duration in the Korean population. These associations also persisted in the group with sustained BMI during the study period. [ABSTRACT FROM AUTHOR]

Background: In the present study, we estimated the population prevalence, associations of congenital heart defect (CHD) and mortality risk for DS using data from National Health Insurance Service (NHIS) and Rare Diseases Registry (RDR). Methods: We collected data on subjects with DS who were registered in the RDR between 2010 and 2015. To estimate associations of CHD and mortality risk of DS, the data of DS subjects were compared with 1:5 age- and sex-matched controls. Results: In 2015, 2077 individuals with DS were identified out of the total population of 51,574,044 South Koreans and the prevalence was 4.03 per 100,000 persons. The trend of DS population prevalence across 10-year-old intervals showed a peak in the group under the age of 10 years (26.0 per 100,000 persons) and then declined sharply after the age of 20 years (0.98 per 100,000 persons at 30– 39 years of age). In subjects with DS, the frequencies of atrial septal defect [odds ratios (OR) =65.9; 95% CI, 84.1– 99.1], ventricular septal defect (OR = 88.1, 95% CI, 57.9– 134.1), patent ductus arteriosus (OR = 56.9, 95% CI, 40.1– 80.8), tetralogy of fallot (OR = 42.1, 95% CI, 19.3– 92.3), or atrioventricular septal defect (OR = 510.0, 95% CI, 126.7– 999.0) were higher than those of age- and sex-matched controls. The risk of death in patients with DS was significantly higher than that of age- and sex-matched controls [hazard ratio (HR) =41.7, 95% CI 20.0– 87.0]. Conclusion: In South Korea, the DS population prevalence was 4.03 per 100,000 persons in 2015. The subjects with DS were more likely to accompany CHD and have higher mortality risk than healthy controls. [ABSTRACT FROM AUTHOR]

No study has examined the associations between vitiligo and smoking. The purpose of this study was to investigate the incidence of vitiligo according to smoking status. We used clinical data from individuals aged over 20 years who received a health examination in the National Insurance Program between 2009 and 2012 (n = 23,503,807). We excluded individuals with pre-existing vitiligo who had ever been diagnosed with vitiligo before the index year (n = 35,710) or who were diagnosed with vitiligo within a year of the index year (n = 46,476). Newly diagnosed vitiligo was identified using claims data from baseline to date of diagnosis or December 31, 2016 (n = 22,811). The development of vitiligo was compared according to self-reported smoking status by a health examination survey. The hazard ratio of vitiligo in current smokers was 0.69 (95% confidence interval; 0.65–0.72) with a reference of never-smokers after adjustment for age, sex, regular exercise, drinking status, body mass index, diabetes mellitus, hypertension, dyslipidemia, history of stroke, and history of ischemic heart diseases. The decreased risk of vitiligo in current smokers persisted after subgroup analysis of sex and age groups. The results suggested there are suppressive effects of smoking on the development of vitiligo. Further studies are needed to evaluate the mechanism of smoking on the development of vitiligo. [ABSTRACT FROM AUTHOR]

Purpose: 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. Methods: 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. Results: 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). Conclusions: 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. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to evaluate the relationship of leg muscle symmetry to the prevalence, radiographic grade, and symptoms of knee osteoarthritis (OA). Method: We conducted a cross-sectional study using data from the Korean National Health and Nutrition Examination Survey (KNHANES), collected in 2010 and 2011. Men and women aged 60 years or older were included. Leg muscle mass was measured using dual-energy X-ray absorptiometry, and the muscle asymmetry index was defined as ∣(left leg muscle mass)/(left and right leg muscle mass) × 100 − 50∣. Statistical analyses were performed to examine the relationships between the muscle asymmetry index and the radiographic grade and knee symptoms. Results: A total of 2548 subjects were included in the analysis. The muscle asymmetry index was positively associated with radiographic knee OA grade and knee pain, especially in men. Men with knee OA and the highest quartile of muscle asymmetry index were 3.3 times more likely to have knee pain compared with those in the lowest quartile. When subjects were divided into four groups by body mass index (BMI) and muscle asymmetry index, subjects with asymmetric obese and men with asymmetric normal BMI had worse grade of radiographic knee OA. Conclusions: Leg muscle asymmetry in men, irrespective of obesity, was associated with significantly higher grade of radiographic knee OA and prevalent knee pain. Longitudinal studies will be needed to determine the cause-and-effect relationship and to determine whether the higher or lower mass, beyond the asymmetry, is associated with radiographic severity or symptomatic knee OA. Key Points •Leg muscle asymmetry was related to prevalence and radiographic severity of knee OA, especially in men. •Leg muscle asymmetry was associated with knee pain. •Those with both leg muscle asymmetry and obesity showed higher prevalence of knee pain and worse radiographic knee OA. [ABSTRACT FROM AUTHOR]

Background: Previous studies reported that stature is inversely related to the risk of cardiovascular disease. However, there is limited evidence on the association between height and lipid profiles. We aimed to examine the association of height with total cholesterol and hypercholesterolemia based on the nationally representative dataset of Korean adults. Methods: The data of 13,701 adults aged ≥19 years who participated in the Korea National Health and Nutrition Examination Survey (2013–2015) were used in this nationwide population-based cross-sectional study. Hypercholesterolemia was defined as a serum total cholesterol level ≥ 240 mg/dL or use of lipid-lowering medications. Multivariable linear regression and logistic regression analyses were used to examine the association of height with mean total cholesterol level and odds ratios (ORs) of hypercholesterolemia. Results: Approximately 17% of participants had hypercholesterolemia. Mean total cholesterol levels decreased in the higher quartile (Q) groups of height after adjusting for confounding variables including age, sex, body mass index, smoking status, alcohol consumption, physical activity, income, educational level, hypertension, and diabetes mellitus (P for trend = 0.035). After adjusting for these potential confounding variables, the adjusted ORs of hypercholesterolemia were significantly lower in the Q3 and Q4 groups than in the Q1 group; ORs decreased in the higher quartile groups of height (OR: 0.83, 95% confidence interval: 0.71–0.99 in Q3; 0.81, 0.69–0.95 in Q4, P for trend = 0.007). The association between height (Q4 vs. Q1–Q3) and hypercholesterolemia was stronger in men or individuals without hypertension or diabetes than in women or individuals with such diseases. Conclusions: Height is inversely associated with total cholesterol level and odds of hypercholesterolemia among Korean adults. Childhood environment related to short stature may be associated with hypercholesterolemia and cardiovascular health in adulthood. [ABSTRACT FROM AUTHOR]

The presence of abdominal obesity and lack of physical activity are both risk factors for the development of hypertension. The aim of this study was to analyze the risk of developing hypertension according to baseline waist circumference (WC). In total, 16 312 476 non-hypertensive participants who were covered by the National Health Insurance Service (NHIS) from 2009 to 2012 in Korea were included in the study. The participants were divided into six groups according to the level of baseline WC with a 5-cm interval starting from 80 cm in men and 75 cm in women. The risk for the future development of hypertension was assessed in 2015 using the claims data on the diagnosis of hypertension and prescription of anti-hypertensive medications. Approximately 7.8% of the participants developed hypertension over a median follow-up of 5.48 years. The proportion of participants who developed hypertension significantly increased from 4.2% in the WC level 1% to 17.5% in the WC level 6. After adjusting for confounding factors, level 6 of the baseline WC had a higher hazard ratio (HR) for the development of hypertension among the 6 levels of baseline with level 3 as the reference (1736; 95% confidence interval [95% CI]: 1.72-1.753). The participants with abdominal obesity had a significantly higher HR than those without abdominal obesity regardless of whether they engage in high- or moderate-intensity physical intensity (1.741; 95% CI: 1.718-1.764). WC had a linear association with the development of hypertension based on this large nationwide population-based cohort study, which was not influenced by physical activity. [ABSTRACT FROM AUTHOR]

Early detection of cancer provides effective treatment and saves lives. The objective of this study was to determine whether serum gastrokine 1 (GKN1) protein is a gastric cancer‐specific diagnostic biomarker. The serum concentration of GKN1 in healthy individuals (median: 6.34 ng/μL, interquartile range (IQR): 5.66‐7.54 ng/μL) was significantly higher compared with the levels in gastric cancer patients (median: 3.48 ng/μL, IQR: 2.90‐4.11 ng/μL; P < .0001). At the optimum cutoff (4.94 ng/μL) of serum GKN1 protein, the sensitivity and specificity were 91.2% and 96.0%, respectively, for gastric cancer. Using serum GKN1 protein as the diagnostic reference, the ROC curve showed a satisfactory diagnostic efficacy with an AUC value of 0.9954 (95% CI 0.9919‐0.9988) and Youden index of 0.8740. In addition, the diagnostic accuracy of the serum GKN1 protein at the optimum cutoff was 0.9675. Interestingly, serum GKN1 concentrations in patients with advanced gastric cancer (AGC; median: 3.11 ng/μL, IQR: 2.72‐3.72 ng/μL) were lower than in patients with early gastric cancer (EGC; median: 4.31 ng/μL, IQR: 3.88‐4.88 ng/μL). The diagnostic accuracies at the optimum serum GKN1 cutoff were 0.8912 and 0.9589 for EGC and AGC, respectively. Furthermore, the serum GKN1 concentrations robustly discriminated the patients with gastric cancer from the patients with colorectal, liver, lung, breast, pancreatic, ovary, and prostatic cancers with AUC values greater than 0.94. These data suggest that serum GKN1 is a promising and highly specific diagnostic biomarker for the prompt detection of early and advanced gastric cancers. [ABSTRACT FROM AUTHOR]

Background: The roles of chronic kidney disease and proteinuria in the development of Parkinson's disease have not been widely studied. The objective of this study was to examine the associations of chronic renal dysfunction and proteinuria with the risk of PD in older adults using cohort data of the whole South Korean population.Methods: We included 3,580,435 individuals aged ≥65 years who had undergone health checkups provided by the National Health Insurance Service of South Korea between 2009 and 2012 and were followed until 2015. Multivariable Cox proportional hazards regression models were performed.Results: During a mean follow-up of 5.2 ± 1.3 years, 30,813 individuals (0.86% of the total population) developed PD. Lower estimated glomerular filtration rate and a higher degree of proteinuria on a dipstick test were associated with higher incidence probability of PD (log-rank P < 0.001). In Cox regression models, chronic renal dysfunction graded by estimated glomerular filtration rate (mL/min/1.73 m2 ) was associated with increased risk of PD after adjusting for potential confounding variables; hazard ratio (95% confidence interval) was 1.13 (1.10-1.17) for estimated glomerular filtration rate 60-90, 1.36 (1.31-1.42) for estimated glomerular filtration rate 30-60, and 1.47 (1.32-1.63) for estimated glomerular filtration rate <30 (P for trend <0.001). Proteinuria ≥1+ was also associated with increased risk of PD development (hazard ratio, 1.12; 95% confidence interval, 1.06-1.18). Coexistence of chronic kidney disease and proteinuria showed an increased hazard ratio of 1.33 (95% confidence interval, 1.23-1.45) for PD occurrence.Conclusions: Our findings suggest that chronic renal dysfunction and dipstick-positive proteinuria may be independent risk factors for the development of PD in older adults. © 2019 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: Limited evidence exists regarding associations between obesity and kidney cancer among Asians. We examined the associations between obesity measures and risk of kidney cancer.Methods: We included 23,313,046 adults who underwent health examinations provided by the Korean National Health Insurance Service 2009-2012 and performed multivariable Cox proportional hazards regression analyses.Results: During 5.4 years of follow-up, 18,036 cases of kidney cancer were recorded, and cumulative incidence was 0.12%. General and abdominal obesity were associated with 1.32-fold increased risk of kidney cancer compared with groups without either obesity status. Underweight individuals showed decreased adjusted hazard ratio (HR) for kidney cancer (0.76, 95% confidence interval: 0.68-0.85) compared to those with normal body mass index (BMI), while the HRs increased among individuals with BMI 23-24.9 kg/m2 (1.23, 1.18-1.28), 25-29.9 kg/m2 (1.41, 1.36-1.46) and ≥30 kg/m2 (1.77, 1.65-1.90) (P for trend < 0.001). HRs of kidney cancer increased with increasing waist circumference (WC) (P for trend < 0.001). Compared to non-obese condition, the coexistence of general and abdominal obesity increased the HR (1.45, 1.40-1.50).Conclusions: This study demonstrated positive associations of BMI and WC with kidney cancer risk. General and abdominal obesity may be risk factors of kidney cancer. [ABSTRACT FROM AUTHOR]

Background: Depression, one of the most costly and common mental disorders, is reported to be associated with lower quality of life (QoL) in several studies. Improved understanding of the associated factors with QoL is necessary to optimize long-term outcomes and reduce disability in patients with depression. Therefore, the aim of this study was to identify factors that are associated with lower QoL among patients with depression. Methods: The study was based on the Korea National Health and Nutrition Examination Survey, a cross-sectional health examination, years 2008 to 2014. The final analyzed sample consisted of a total of 1,502 study subjects who had been diagnosed by clinicians as having depression. A multivariate logistic regression model was performed to exam the association between the clinical characteristics (age, sex, demographic and health-related characteristics) and QoL. Analysis of covariance was also used to analyze EQ-5D according to mental health. Results: Older age, lower level of education, lower income, worse subjective perception of health, unemployment, obesity and mental health struggles were found to be significantly associated with low QoL in depressive individuals after adjustment for multiple covariates. Conclusions: This study has outlined grounding data in identifying patients who are at risk of QoL impairment. Policy makers should direct their interests to these individuals and provide appropriate management. [ABSTRACT FROM AUTHOR]

Background: Although several studies have reported a correlation between Behçet's disease (BD) and Parkinson's disease, this association has not yet been clarified. Objective: To determine the risk of Parkinson's disease in patients with BD. Methods: BD patients (n = 17,179; mean age, 51.12±8.09 years; male, 34.95%) without known previous diagnosis of Parkinson's disease were selected from the Korean National Health Insurance Database between 2010 and 2013. An age- and gender-matched control population of individuals without BD was randomly sampled at a ratio of 3:1 (n = 34,575). Both cohorts were followed for development of Parkinson's disease until 2015. Results: Among a total of 11,525 BD patients, 50 (0.43%) developed Parkinson's disease, whereas only 51 among the 34,575 individuals in the non-BD group developed Parkinson's (0.15%, P < 0.0001). The incidence of Parkinson's disease was significantly higher in BD patients than in controls. In addition, during the follow-up period, patients with BD were more likely to be diagnosed with Parkinson's disease than those in the non-BD group. Conclusions: BD patients had a higher risk of Parkinson's disease compared to non-BD controls. Physicians should carefully monitor patients with BD for potential development of Parkinson's disease. [ABSTRACT FROM AUTHOR]

Objective: This study examined the association between baseline BMI, percentage weight change, and the risk of dementia in patients newly diagnosed with type 2 diabetes.Research Design and Methods: Using the South Korean National Health Insurance Service-National Health Screening Cohort database, we identified 167,876 subjects aged ≥40 years diagnosed with new-onset type 2 diabetes between 2007 and 2012. Their weight changes were monitored for ∼2 years after diagnosis, with follow-up assessments occurring for an average of 3.5 years. The hazard ratios (HRs) and Bonferroni-adjusted 95% CIs of all-cause dementia, Alzheimer disease (AD), and vascular dementia were estimated using multivariable Cox proportional hazards regression models.Results: We identified 2,563 incident dementia cases during follow-up. Baseline BMI among patients with new-onset type 2 diabetes was inversely associated with the risk of all-cause dementia and AD, independent of confounding variables (P for trend <0.001). The percentage weight change during the 2 years after a diagnosis of type 2 diabetes showed significant U-shaped associations with the risk of all-cause dementia development (P < 0.001); the HRs of the disease increased significantly when weight loss or gain was >10% (1.34 [95% CI 1.11-1.63] and 1.38 [1.08-1.76], respectively). Additionally, weight loss >10% was associated with an increased risk of AD (HR 1.26 [95% CI 1.01-1.59]).Conclusions: A lower baseline BMI was associated with increased risks of all-cause dementia and AD in patients with new-onset type 2 diabetes. Weight loss or weight gain after the diagnosis of diabetes was associated with an increased risk of all-cause dementia. Weight loss was associated with an increased risk of AD. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the gestational age-specific risk of stillbirth according to the maternal age group particularly regarding stillbirth risk at the end of pregnancy.Methods: This study was a retrospective national cohort study of all singleton term pregnancy using the Korean Vital Statistics database (n = 2,798,542). We evaluated the risk of stillbirth by gestational week in mothers aged 20-49 years according to maternal age group and neonatal birth weight.Results: The risk of stillbirth in women aged 41 years and older was significantly higher than in women aged 20-29 years between 37 and 40 weeks' gestation. The stillbirth rate per 10,000 ongoing pregnancy in women aged 37-38 years at 39 weeks' gestation (4.22, 95% confidence intervals [CI] 3.01-5.90) and that in women aged 39-40 years at 40 weeks' gestation (8.15, 95% CI 4.83-13.77) were significantly higher in comparison with in those aged 20-29 years at 39 weeks' gestation (1.95, 95% CI 1.64-2.33) and at 40 weeks' gestation (2.59, 95% CI 2.1-3,18). The risk of stillbirth showed an increasing pattern at 40 gestational weeks, in women aged 39 years and older.Conclusions: Delivery plan need to be set up and supported to decrease rates of stillbirth at term in women aged 35 years and older with other risk factors and in women aged 37 years and older regardless of risk factors, and especially in women older than 40 years of age. [ABSTRACT FROM AUTHOR]

The relationship between psoriasis and cancer has not yet been established. The aim of this study was to evaluate the association of psoriasis with certain cancers using national statistics. All patients with psoriasis (n = 892 089; 51.7% male) and age‐ and sex‐matched control subjects (n = 4 460 445) at a 5:1 ratio were enrolled using data from the National Health Insurance Service between 2007 and 2014 in Korea. In psoriatic subjects, overall cancer risk was higher than for subjects without psoriasis after adjusting for income level, diabetes, hypertension, dyslipidemia and place of residence (hazard ratio, 1.065; 95% CI, 1.049–1.081). The risk of cancer increased in the following order: prostate, thyroid, liver, ovarian, lung, leukemia, skin, multiple myeloma, lymphoma and testicular. The severity and sex of psoriatic patients also had different cancer risks. In psoriatic patients, a slightly increased risk for specific malignant neoplasms was shown. Therefore, periodic screening for cancer risk is recommended in patients with psoriasis. [ABSTRACT FROM AUTHOR]

Background: Overweight is known as a risk factor for ischemic stroke. However, the effect of weight change on the development of ischemic stroke remains controversial. We investigated the relationship between weight change and the risk of ischemic stroke using a nationwide population-based cohort. Methods: Our study enrolled 11,084,683 participants (Mean age 49.7±13.5 years, range 20–114 years) in the Korean National Health Screening Program from 2009 to 2012. Weight change was calculated using the difference between the baseline weight and the weight at health screening four years prior to the baseline. The occurrence of newly-diagnosed ischemic stroke was observed until the end of 2015. We categorized the study population according to weight change and performed multivariable analysis to compare the risk. Results: Ischemic stroke was newly diagnosed in 113,591 subjects. The crude incidence rates of ischemic stroke per 1000 person-years according to the change in body weight were 3.059, 1.906, and 1.491 in the <-5%, ±5%, and ≥+5% groups, respectively. After adjusting all variables, the hazard ratio (HR) of ischemic stroke was higher in subjects who underwent weight loss (HR 1.152) or weight gain (HR 1.087) than in those who maintained their weight. When analyzed by eight groups of 5% intervals, the risk showed a U-shaped curve with those who maintained their weight showing the lowest risk. Conclusions: The risk of ischemic stroke was gradually increased in those who lost or gained more than 5% of their weight over four years, after adjusting for confounders. We should be aware of the increased risk of ischemic stroke in people who undergo weight change and should identify and manage the cause of weight change. [ABSTRACT FROM AUTHOR]

Purpose: To examine the competing risks of stillbirth versus infant death and to evaluate the optimal time of delivery in the population of small for gestational age (SGA) and non-SGA late preterm and term fetuses. Methods: This was a retrospective national cohort study of all singleton births between 34 0/7 and 42 6/7 weeks of gestation using the Korean vital statistics (n = 2,106,159). We compared the risk of infant mortality with a composite of fetal–infant mortality risk that would occur after expectant management for one additional week and evaluated the optimal time of delivery, in SGA and non-SGA pregnancies. Results: In the total population, the risk of expectant management became significantly higher than the risk of delivery, at 39 weeks and beyond, similar with non-SGA group. In the SGA group, the risk of stillbirth was significantly greater at all GAs than for non-SGA pregnancies, and the risk of infant death was significantly increased until 38 weeks (25.8 per 10,000 live births, 95% CI 20.11–32.47), and the risk of stillbirth was significantly increased at 41 weeks (11.65 per 10,000 ongoing pregnancies, 95% CI 6.95–18.09), compared to 39 weeks (12 per 10,000 live births, 95% CI 8.98–15.64 and 5.12 per 10,000 ongoing pregnancies, 95% CI 3.84–6.66, respectively). Conclusion: In Korean women, delivery between 39 and 41 weeks minimizes fetal/infant mortality, in non-SGA pregnancies. In uncomplicated SGA pregnancies, delivery between 39 and 40 weeks can be considered to decrease risk of infant death and stillbirths. [ABSTRACT FROM AUTHOR]

The epidemiology of pemphigus varies among racial populations worldwide. Trends in the incidence of pemphigus have not been investigated based on the Korean National Health Insurance database. This study investigated the incidence and death rate of pemphigus with age using nationwide population data in South Korea. A nationwide population‐based cohort study was performed using the Korean National Health Insurance Claims Database from 2006 to 2015. The incidence of pemphigus vulgaris (PV) per 1 000 000 person‐years was 2.059 (1.885 for males and 2.234 for females), and for pemphigus foliaceus (PF) 1.138 (1.205 males and 1.07 for females). The incidence of PV and PF increased with age. The incidence was not different between the habitat and household income. These incidence of PV and PF was significantly higher in subjects with comorbid metabolic conditions, such as diabetes mellitus, hypertension and dyslipidemia. The death rate per 1000 person‐years in PV and PF patients increased with age after adjustment for the presence of comorbidities compared with standard death rate. This study showed that age is an important factor in PV and PF patients in Korea. [ABSTRACT FROM AUTHOR]

This study aimed to examine whether the characteristics of mental health and sleep duration, alone or in combination, are associated with menstrual cycle irregularity. This population-based, cross-sectional study analyzed the data from 4445 women aged 19-49 years, who participated in the Korea National Health and Nutrition Examination Survey 2010-2012. A structured questionnaire was used to assess mental health characteristics, sleep duration, and menstrual cycle irregularity. A multivariable logistic regression analysis was performed. High stress, depressive mood, and suicidal ideation were associated with increased risk of menstrual cycle irregularity after adjusting for confounding variables (odds ratio [95% confidence interval] = 1.33 [1.07-1.65], 1.56 [1.17-2.07], and 1.37 [1.01-1.87], respectively). Short sleep duration (≤ 5 h a day) was significantly associated with higher odds of severe menstrual cycle irregularity with menstrual interval of greater than 3 months (2.67 [1.35-5.27]). Participants with sleep duration of ≤ 5 h a day with psychological stress, depressive mood, or suicidal ideation had higher odds of menstrual cycle irregularity (1.96 [1.26-3.05], 2.86 [1.50-5.44], and 2.25 [1.18-4.29]). This study suggests positive associations of mental health problems and short sleep duration with menstrual cycle irregularity among Korean female adults. Therefore, strategies to deal with psychological stress, depressive mood, and sleep duration are needed for improving the reproductive health of women suffering from menstrual disturbances. [ABSTRACT FROM AUTHOR]