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A heterocycle-to-heterocycle strategy is presented for the preparation of highly fluorescent and solvatochromic dibenzonaphthyridinones (DBNs) via methodology that leads to the formation of a tertiary, spiro-fused carbon center. A linear correlation between the results of photophysical experiments and time dependent density functional theory calculations was observed for the λ(max) of excitation for DBNs with varying electronic character.

The article focuses on assessing the performance of ChatGPT when responding to dermatology specialty certification examination-style questions in both English and Korean. Topics include the methodology used to evaluate ChatGPT's responses, the analysis of its correct response rates across different cognitive functions and evaluation categories, and the implications of language variations on its performance in a medical context.

This study investigates the influence of extrusion and deformation temperatures on the mechanical properties of the AZ61 Mg alloy. Increasing the extrusion temperature from 300 to 400 °C led to larger grain size and higher basal texture intensity. At 400 °C, the AZ61 alloy exhibited more Al–Mn phases and fewer Mg17Al12 phases, indicating enhanced dissolution of Mg17Al12 in the α-Mg matrix. Uniaxial tensile tests were conducted at room temperature (RT) and cryogenic temperature (CT, −150 °C). Despite grain growth, a higher yield strength (YS) was achieved at higher extrusion temperatures due to the texture-strengthening mechanism. However, during deformation at CT, the higher YS was primarily attributed to the formation of multiple twinning within individual grains, causing twinning interactions. These twin-interacting boundaries create additional barriers to dislocation movement. Notably, the AZ61 sample extruded at 400 °C demonstrated the formation of stacking faults during deformation at CT, with dislocations accumulating around the faults. This contributed to the best strength without compromising ductility in this sample.

Abstract Objective The effect of body composition change on the risk of dementia is not clear. This study analyzed the associations of changes in predicted lean body mass index (pLBMI), predicted appendicular skeletal muscle mass index (pASMI), and predicted body fat mass index (pBFMI) with the risk of dementia. Methods In this nationwide cohort study, data were obtained from the Korean National Health Insurance Service database. The exposure was defined as changes in pLBMI, pASMI, and pBFMI derived from validated prediction equations. The outcome was dementia, defined based on the dementia diagnosis with prescription of anti‐dementia medication. Cox proportional hazards regression analyses were performed to obtain the hazard ratio with a 95% confidence interval for risk of dementia according to changes in predicted body composition. Results A total of 13,215,208 individuals with no prior record of dementia who underwent health screenings twice between 2009–2010 and 2011–2012 were included. A 1‐kg/m2 increase in pLBMI and pASMI had an association with reduced risk of dementia (aHR: 0.85, 95% CI 0.84–0.87; aHR: 0.70, 95% CI 0.69–0.72, respectively for men, and aHR: 0.69, 95% CI 0.67–0.71; aHR: 0.59, 95% CI 0.57–0.61, respectively for women). A 1‐kg/m2 increase in pBFMI had an association with a raised risk of dementia (aHR: 1.19, 95% CI 1.17–1.21 for men and aHR: 1.53, 95% CI 1.48–1.57 for women). These results remained consistent regardless of sex or weight change. Interpretation Increase in pLBMI or pASMI, or reduction in pBFMI was linked to lower risk of dementia.

Background/Aims To determine the association between evolutionary changes in metabolic dysfunction-associated steatotic liver disease (MASLD) status and the risk of hepatocellular carcinoma (HCC) in a nationwide population-based cohort. Methods Information on study participants was derived from the Korea National Health Insurance Service database. The study population consisted of 5,080,410 participants who underwent two consecutive biennial health screenings between 2009 and 2012. All participants were followed up until HCC, death, or 31 December 2020. The association of evolutionary changes in MASLD status, as assessed by the fatty liver index and cardiometabolic risk factors, including persistent non-MASLD, resolved MASLD, incident MASLD, and persistent MASLD, with HCC risk was evaluated using multivariable-adjusted Cox proportional hazards regression. Results Among the 5,080,410 participants with 39,910,331 person-years of follow-up, 4,801 participants developed HCC. The incidence of HCC in participants with resolved, incident, and persistent MASLD was approximately 2.2-, 2.3-, and 4.7-fold higher, respectively, than that in those with persistent non-MASLD among the Korean adult population. When stratifying the participants according to the evolutionary change in MASLD status, persistent (adjusted hazard ratio [aHR], 2.94; 95% confidence interval [CI], 2.68–3.21; P

In this study, a numerical analysis was conducted on the ductile fracture of a 2-mm diameter Mg-1Zn-0.5Mn-0.5Sr-0.1Ca alloy wire during drawing. The hexagonally close-packed crystal structure of Mg alloys causes asymmetric fracture behavior, especially in the compression region. The aim of this study is to develop a comprehensive damage model for Mg alloy wire that accurately predicts ductile fracture, with a focus on the compression region. A novel experimental method was introduced to measure the ductile fracture of Mg alloy wires under different stress states. The wire drawing process was simulated using the Generalized Incremental Stress-State dependent damage (GISSMO) Model and the Semi-Analytical Model for Polymers (SAMP) model. The damage model's prediction and the experimental results were found to be in excellent agreement, especially in determining crack initiation. Computational analysis established a safe zone diagram for die angle and reduction ratio, and experimental validation confirmed the feasibility of this approach. The proposed damage model can provide a practical and reliable analysis for optimizing the drawing process of Mg alloy wire.

Abstract Although some studies conducted about the risk of cholecystectomy and cardiovascular disease, there was a limit to explaining the relationship. We investigated the short-term and long-term relationship between cholecystectomy and cardiovascular disease, and evidence using the elements of the metabolic index as an intermediate step. It was a retrospective cohort study and we used the National Health Insurance Service database of South Korea between 2002 and 2015. Finally, 5,210 patients who underwent cholecystectomy and 49,457 at 1:10 age and gender-matched controls of subjects were collected. The main results was estimated by Multivariate Cox proportional hazard regression to calculate the hazard ratio (HR) with 95% confidence interval (CI) for risk of cardiovascular disease after cholecystectomy. Regarding short-term effects of cholecystectomy, increased risk of cardiovascular disease (aHR 1.35, 95% CI 1.15–1.58) and coronary heart disease (aHR 1.77, 95% CI 1.44–2.16) were similarly seen within 2 years of surgery. When analyzing the change in metabolic risk factors, cholecystectomy was associated with a change in systolic blood pressure (adjusted mean [aMean]: 1.51, 95% CI: [− 1.50 to − 4.51]), total cholesterol (aMean − 14.14, [− 20.33 to 7.95]) and body mass index (aMean − 0.13, [− 0.37 to 0.11]). Cholecystectomy patients had elevated risk of cardiovascular disease in the short-term, possibly due to the characteristics of the patient before surgery. The association of cholecystectomy and cardiovascular disease has decreased after 2 years in patients who underwent cholecystectomy, suggesting that because of improvement of metabolic health, cholecystectomy-associated elevation of cardiovascular disease risk may be ameliorated 2 years after cholecystectomy.

Background: Although recent studies indicated that antibiotics may be a risk factor for lung cancer, further understanding is needed. We investigated the association of long-term antibiotic exposure with lung cancer risk. Methods: This population-based retrospective cohort study investigated 6,214,926 participants aged ≥ 40 years who underwent health screening examinations (2005–2006) from the Korean National Health Insurance Service database. The date of the final follow-up was December 31, 2019. Exposures were the cumulative days of antibiotics prescription and the number of antibiotics classes. The adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for lung cancer risk according to antibiotic use were assessed using multivariable Cox proportional hazards regression. Results: Compared with the antibiotic non-user group, participants with ≥ 365 days of antibiotics prescribed had a significantly increased risk of lung cancer (aHR, 1.21; 95% CI, 1.16–1.26). Participants with ≥ 365 days of antibiotics prescribed also had a significantly increased risk of lung cancer (aHR, 1.21; 95% CI, 1.17–1.24) than 1–14 days of the antibiotic user group. The results were also consistent in competing risk analyses and adjusted Cox regression models that fitted restricted cubic spline. Compared with the antibiotic non-user group, ≥ 5 antibiotic classes prescribed group had a higher lung cancer risk (aHR, 1.15; 95% CI, 1.10–1.21). Conclusion: The long-term cumulative days of antibiotic use and the increasing number of antibiotics classes were associated with an increased risk of lung cancer in a clear duration-dependent manner after adjusting for various risk factors.

Abstract Major post-cessation metabolic changes include weight gain and hyperglycemia. However, the association of post-cessation change in fasting serum glucose (FSG) with risk of fatty liver remains unclear. A total of 111,106 participants aged 40 and above who underwent health screening at least once in two examination periods were extracted from the Korean National Health Insurance Service-National Sample Cohort. Fatty liver status was evaluated using the Korean National Health and Nutrition Examination Survey nonalcoholic fatty liver disease (K-NAFLD) score. Linear and logistic regression were used to calculate the adjusted mean (aMean) and adjusted odds ratio (aOR) with 95% confidence intervals. Compared to stable (aMean 0.10; 95% CI 0.03–0.18) and decline (aMean − 0.60; 95% CI − 0.71 to 0.49) groups, FSG elevation (aMean 1.28; 95% CI 1.16–1.39) was associated with higher K-NAFLD score even within different body mass index change groups. Risk of fatty liver was significantly reduced among participants with stable (aOR 0.38; 95% CI 0.31–0.45) and declined (aOR 0.17; 95% CI 0.13–0.22) FSG levels after smoking cessation compared to FSG elevation group. This study suggests that quitters with elevated FSG are associated with higher NAFLD risk and may benefit from careful monitoring of FSG levels and management of other cardiovascular risk factors.

Abstract Despite many diabetic patients having hypercholesterolemia, the association of total cholesterol (TC) levels with CVD risk in type 2 diabetes (T2D) patients is unclear. Diagnosis of type 2 diabetes often leads to changes in total cholesterol (TC) levels. Thus, we examined whether changes in TC levels from pre- to post-diagnosis of T2D were associated with CVD risk. From the National Health Insurance Service Cohort, 23,821 individuals diagnosed with T2D from 2003 to 2012 were followed-up for non-fatal CVD incidence through 2015. Two measurements of TC, 2 years before and after T2D diagnosis, were classified into 3 levels (low, middle, high) to define changes in cholesterol levels. Cox proportional hazards regression was performed to estimate adjusted hazards ratios (aHRs) and 95% confidence intervals (CIs) for the associations between changes in cholesterol levels and CVD risk. Subgroup analyses were performed by use of lipid-lowering drugs. Compared with low–low, aHR of CVD was 1.31 [1.10–1.56] for low–middle and 1.80 [1.15–2.83] for low–high. Compared with middle–middle, aHR of CVD was 1.10 [0.92–1.31] for middle–high but 0.83 [0.73–0.94] for middle–low. Compared with high–high, aHR of CVD was 0.68 [0.56–0.83] for high–middle and 0.65 [0.49–0.86] for high–low. The associations were observed regardless of use of lipid-lowering drugs. For diabetic patients, management of TC levels may be important to lower CVD risk.

Abstract Hemoglobin variability is known to increase cardiovascular mortality in chronic kidney disease, but the association of hemoglobin variability with the risk of cardiovascular disease (CVD) in the general population is yet unclear. This retrospective cohort study based on ‘the South Korean National Health Insurance Service database’ consisted of 198,347 adults who went through all three health examinations. Hemoglobin variability is defined as the average successive variability of three separate hemoglobin values from each health screening period. Participants were followed up for 6 years to determine the risk of coronary heart disease and stroke. We used multivariate Cox proportional hazards regression to examine the adjusted hazard ratios for CVD according to hemoglobin variability. Per 1 unit increase of hemoglobin variability, the risk for CVD (aHR 1.06, 95% CI 1.02–1.09) and stroke (aHR 1.08, 95% CI 1.03–1.13) increased significantly. The risk-increasing trend was preserved in the low-to-moderate risk group of CVDs (aHR 1.07, 95% CI 1.02–1.11). This result suggests that subjects with high hemoglobin variability who would otherwise be categorized as having low-to-moderate CVD risk may have higher risk of CVD than those with low hemoglobin variability.

Background/Aims: Smoking is considered a risk factor for the development of nonalcoholic fatty liver disease (NAFLD). However, the association of a weight change after a change in smoking status and the risk of NAFLD remains undetermined. Methods: This study used the Korean National Health Insurance Service-National Sample Cohort. Based on the first (2009 to 2010) and second (2011 to 2012) health examination periods, 139,180 adults aged at least 40 years were divided into nonsmoking, smoking cessation, smoking relapse, and sustained smoking groups. NAFLD was operationally defined using the fatty liver index. The adjusted odds ratio (aOR) and 95% confidence interval (CI) were calculated using multivariable-adjusted logistic regression. Results: Compared to nonsmoking with no body mass index (BMI) change, the risk of NAFLD was significantly increased among subjects with BMI gain and nonsmoking (aOR, 4.07; 95% CI, 3.77 to 4.39), smoking cessation (aOR, 5.52; 95% CI, 4.12 to 7.40), smoking relapse (aOR, 7.51; 95% CI, 4.81 to 11.72), and sustained smoking (aOR, 6.65; 95% CI, 5.33 to 8.29), whereas the risk of NAFLD was reduced among participants with BMI loss in all smoking status groups. In addition, smoking cessation (aOR, 1.76; 95% CI, 1.35 to 2.29) and sustained smoking (aOR, 1.64; 95% CI, 1.39 to 1.94) were associated with higher risk of NAFLD among participants with no BMI change. The liver enzyme levels were higher among participants with smoking cessation and BMI gain. Conclusions: Monitoring and management of weight change after a change in smoking status may be a promising approach to reducing NAFLD.

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

Background/Aims Accumulating evidence suggests a link between non-alcoholic fatty liver disease (NAFLD) and brain health. However, population-based evidence on the association between NAFLD and dementia remains unclear. This study was conducted to determine the association between NAFLD and incident dementia. Methods The study population included 608,994 adults aged ≥60 years who underwent health examinations between 2009 and 2010. Data were collected from the Korean National Health Insurance Service database. NAFLD was assessed using the fatty liver index (FLI). A Cox proportional hazards regression model was used to determine the association between NAFLD and dementia. Results During the 6,495,352 person-years of follow-up, 48,538 participants (8.0%) developed incident dementia. The participants were classified into low (FLI

Background/Aims: Metabolic dysfunction (MD)-associated fatty liver disease is a new positive diagnostic criterion based on hepatic steatosis and MD. However, a comprehensive evaluation on the association of MD and hepatic steatosis with incident cardiovascular disease (CVD) has yet to be performed. Methods: This retrospective cohort study included 333,389 participants from the Korean National Health Insurance Service database who received a health examination between 2009 and 2010. Hepatic steatosis was defined using the Korean National Health and Nutrition Examination Survey-derived nonalcoholic fatty liver disease scoring system. Cox proportional hazards regression was adopted to determine the adjusted hazard ratio (aHR) with 95% confidence interval (CI) for CVD according to the presence of hepatic steatosis and MD, as well as the composite term. Results: This study included 179,437 men and 153,952 women with a median age of 57 years. Hepatic steatosis with MD (aHR, 2.00; 95% CI, 1.89 to 2.13) and without MD (aHR, 1.30; 95% CI, 1.10 to 1.54) significantly increased the risk of CVD compared to no steatosis without MD (reference). However, steatosis revealed no significant difference in the risk of CVD compared to no steatosis among participants with one MD (aHR, 1.09; 95% CI, 0.91 to 1.30). In participants with steatosis, the presence of one and ≥2 MDs had aHR values of 1.25 (95% CI, 0.87 to 1.79) and 1.71 (95% CI, 1.22 to 2.41), respectively, compared to no MD. Conclusions: Combined consideration of hepatic steatosis and MD was significantly associated with increased CVD risk and showed better predictive performance for CVD than hepatic steatosis or MD alone.

Abstract A number of studies have proposed an inverse association between allergic diseases and risk of cancer, but only a few studies have specifically investigated the risk of primary liver cancer, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). The aim of this study was to evaluate the association of allergic diseases with risk of primary liver cancer. We conducted a retrospective cohort study of the Korean National Health Insurance Service database consisted of 405,512 Korean adults ages 40 and above who underwent health screening before January 1st, 2005. All participants were followed up until the date of liver cancer, death, or December 31st, 2013, whichever happened earliest. Those who died before the index date or had pre-diagnosed cancer were excluded from the analyses. Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for risk of primary liver cancer according to the presence of allergic diseases, including atopic dermatitis, asthma, and allergic rhinitis. The aHR (95% CI) for overall liver cancer among allergic patients was 0.77 (0.68–0.87) compared to those without allergic disease. Allergic patients had significantly reduced risk of HCC (aHR, 0.72; 95% CI 0.62–0.85) but not ICC (aHR, 0.95; 95% CI 0.73–1.22). The presence of allergies was associated with significantly lower risk of liver cancer among patients whose systolic blood pressure is lower than 140 mmHg (aHR, 0.64; 95% CI 0.62–0.78 for overall liver cancer; aHR, 0.64; 95% CI 0.52–0.78 for HCC) but this effect was not observed among patients whose systolic blood pressure is higher than 140 mmHg (aHR, 0.91; 95% CI 0.71–1.18 for overall liver cancer; aHR, 0.91; 95% CI 0.71–1.18 for HCC) The aHR (95% CI) for overall liver cancer of allergic patients with and without chronic hepatitis virus infection were 0.60 (95% CI 0.44–0.81) and 0.77 (95% CI 0.64–0.93), respectively. In addition, allergic patients without cirrhosis showed significantly lower risk of overall liver cancer (aHR, 0.73; 95% CI 0.63–0.83). Patients with allergic diseases have significantly lower risk of primary liver cancer compared to those without allergic diseases, which supports the rationale for immunotherapy as an effective treatment for liver cancer.

Abstract There is growing evidence that suggests a potential association between particulate matter (PM) and suicide. However, it is unclear that PM exposure and suicide death among major depressive disorder (MDD) patients, a high-risk group for suicide. We aimed to assess the effect of short-term exposure to PM on the risk of suicide in MDD patients who are at high risk for suicide. We investigated the risk of suicide among 922,062 newly-diagnosed MDD patients from 2004 to 2017 within the Korean National Health Insurance Service (NHIS) database. We identified 3,051 suicide cases from January 1, 2015, to December 31, 2017, within the death statistics database of the Korean National Statistical Office. PMs with aerodynamic diameter less than 2.5 μm (PM2.5), less than 10 μm (PM10), and 2.5–10 μm (PM2.5–10) were considered, which were provided from the National Ambient Air Monitoring System in South Korea. Time-stratified case-crossover analysis was performed to investigate the association of particulate matter exposure to suicide events. The risk of suicide was significantly high upon the high level of exposure to PM2.5, PM2.5–10 (coarse particle) and PM10 on lag 1 (p for trend

Abstract Background Little is known about the association of changes in two body components, muscle and fat mass, with the risk of cardiovascular disease (CVD) among young adults. We investigated the association of changes in predicted lean body mass index (LBMI), appendicular skeletal muscle mass index (ASMI), and body fat mass index (BFMI) with the development of CVD among young adults. Methods This nationwide, population‐based cohort study included 3 727 738 young adults [2 406 046 (64.5%) men and 1 321 692 (35.5%) women] aged 20–39 years without a previous history of CVD who underwent two health screening examinations during 2009–2010 and 2011–2012. Using validated and robust prediction equations, we calculated the changes in predicted LBMI, ASMI, and BFMI from the first to the second examinations. Results The mean (SD) age was 32.2 (4.9) years, and 2 406 046 (64.5%) of the participants were men. A total of 23 344 CVD events were detected during 22 257 632 person‐years of follow‐up. Each 1 kg/m2 increase in predicted LBMI and ASMI change was associated with a reduced risk of CVD among men [adjusted hazard ratio (aHR): 0.86, 95% confidence interval (CI) 0.82–0.91; aHR: 0.76, 95% CI 0.69–0.82, respectively] and women (aHR: 0.77, 95% CI 0.63–0.95; aHR: 0.75, 95% CI 0.59–0.96). Each 1 kg/m2 increase in predicted BFMI change was associated with an increased risk of CVD among men (aHR: 1.16, 95% CI 1.10–1.22) and women (aHR: 1.32, 95% CI 1.06–1.65). In both sexes, decreases in predicted LBMI and ASMI were associated with greater CVD risk, and decreased predicted BFMI was associated with a reduced CVD risk. Those who maintained their BMI between −1 and +1 kg/m2 also had a decreased risk of CVD per 1 kg/m2 increase in predicted LBMI and ASMI change among men (aHR: 0.86, 95% CI 0.80–0.92; aHR: 0.85, 95% CI 0.76–0.95) and women (aHR: 0.62, 95% CI 0.47–0.83; aHR: 0.59, 95% CI 0.44–0.80) and had a greater risk of CVD per 1 kg/m2 increase in predicted BFMI change among men (aHR: 1.17, 95% CI 1.10–1.25) and women (aHR: 1.64, 95% CI 1.20–2.23). Regardless of changes in weight, such as from normal to obese or vice versa, these results were consistent. Conclusions Among young adults, increased predicted muscle mass or decreased predicted fat mass were associated with a reduced risk of development of CVD. Decreased predicted muscle mass or increased predicted fat mass were associated with an elevated risk of development of CVD.

Abstract Numerous studies have reported that antibiotics could lead to diabetes, even after adjusting for confounding variables. This study aimed to determine the causal relationship between antibiotics use and diabetes in a nationally representative cohort. This retrospective cohort study included adults aged 40 years or older who were enrolled in the Korean National Health Insurance Service-Health Screening Cohort. Antibiotic exposure was assessed from 2002 to 2005 and newly diagnosed diabetes mellitus was determined based on diagnostic codes and history of antidiabetic medication use from 2006 to 2015. Multivariate Cox proportional hazards model was used to assess the association between antibiotic use and diabetes incidence. The mean age of the 201,459 study subjects was 53.2 years. People who used antibiotics for 90 or more days had a higher risk of diabetes (adjusted hazard ratio [aHR] 1.16, 95% confidence interval [CI] 1.07–1.26) compared to non-users. Those who used five or more classes of antibiotics had a higher risk of diabetes than those who used one antibiotic class (aHR 1.14; 95% CI 1.06–1.23). The clear dose-dependent association between antibiotics and diabetes incidence supports the judicious use of antibiotics in the future.

For load-bearing applications, biodegradable Mg alloys require high strength and slow degradation rates to support bone regeneration. This study proposes a design guide of Mg-Zn-Mn-Sr-Ca (ZMJX) alloys for load-bearing Mg implants using machine learning. To this end, it quantitatively investigates the correlation between 4 alloying elements with content of 0–3 wt%, ultimate compressive strength (UCS) and in vitro corrosion rate (CR) in ZMJX alloys. Cascade-forward neural networks predict UCS and CR with high accuracy of over 0.95 for a total of 840 data points. Random forest regression identifies Zn as a major determinant of UCS and CR. Based on this, three chemical compositions are recommended with improved compressive strength and in vitro corrosion resistance by well-verified neural network models. The proposed Mg alloys have UCS of 244–305 MPa and CR of 0.31–0.83 mm/y according to the change of the Zn content. These results can not only provide deep insights into ZMJX alloys, but also recommend a compositional window for load-bearing Mg implants.

IntroductionIt is known that biological risk factors and lifestyle behaviors are important determinants of dementia. However, there has been yet to be sufficient evidence to prove that community-level social capital is one of the determinants of dementia. This retrospective cohort study is a large, long-term, population-based study that investigated the association between community-level social trust and the risk of dementia in the Republic of Korea.MethodsData came from the Korean National Health Insurance Service database. The community-level social trust values were determined by the Korean Community Health Survey. The study population consisted of 1,974,944 participants over 50 years of age and was followed up from 1 January 2012 to 31 December 2019 with a latent period of 5 years from 1 January 2012 to 31 December 2016. Cox proportional hazards regression was utilized to obtain the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the risk of dementia according to social trust quintiles.ResultsParticipants within the highest quintile of community-level social trust had a lower risk for overall dementia (aHR, 0.90; 95% CI, 0.86–0.94) and Alzheimer's disease (aHR, 0.90; 95% CI, 0.85–0.94) compared to those within the lowest quintile of community-level social trust. The alleviating trend association of high community-level social trust on dementia risk was maintained regardless of whether the participants had health examinations.ConclusionsOur findings suggest that higher community-level social trust is associated with a reduced risk of dementia. Community-level social trust is a crucial indicator of dementia and improving community-level social trust may lead to a lower risk of dementia.

Background: The possible relation between antibiotic exposure and the alteration of gut microbiota, which may affect dementia risk, has been revealed. However, the association between antibiotics and dementia incidence has rarely been studied. We aimed to determine the association between antibiotic exposure and the risk of dementia.Methods: This population-based retrospective cohort study used data from the National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) in South Korea. Exposure was the cumulative days of antibiotic prescription from 2002 to 2005. Newly diagnosed overall dementia, Alzheimer’s disease (AD), and vascular dementia (VD) were identified based on diagnostic codes and prescriptions for dementia-related drugs. The follow-up investigation was carried out from 1 January 2006 to 31 December 2013. The Cox proportional hazards regression was used to assess the association between cumulative antibiotic prescription days and dementia incidence.Results: A total of 313,161 participants were analyzed in this study. Compared to antibiotic non-users, the participants who used antibiotics for 91 or more days had an increased risk of overall dementia [adjusted hazard ratio (aHR), 1.44; 95% confidence interval (CI), 1.19–1.74], AD (aHR, 1.46; 95% CI, 1.17–1.81), and VD (aHR, 1.38; 95% CI, 0.83–2.30). Those who used five or more antibiotic classes had higher risks of overall dementia (aHR, 1.28; 95% CI, 1.00–1.66) and AD (aHR, 1.34; 95% CI, 1.00–1.78) than antibiotic non-users.Conclusion: Antibiotic exposure may increase the risk of dementia in a cumulative duration-dependent manner among adult participants. Future studies are needed to assess the causality between the long-term prescription of antibiotics and dementia risk.

Abstract Background There is no evidence whether it is best to stop drinking alcohol at all or whether it is okay to drink a little in that light-to-moderate alcohol use was associated with low cardiovascular disease (CVD) compared to non-drinker among colorectal cancer (CRC) survivors, who are regarded as vulnerable to CVD. Therefore, we evaluated the association between alcohol consumption and incident CVD among long-term survivors of CRC. Methods This population-based, retrospective cohort study utilized data from the Korean National Insurance Service of 20,653 long-term survivors of CRC diagnosed between 2006 and 2012. Participants were followed up to the date of CVD, death, or December 31, 2018. All patients were categorized according to their daily alcohol consumption (g/day). The outcomes were incident CVD, including ischemic heart disease (IHD) and ischemic and hemorrhagic stroke, analyzed using the Cox proportional hazards regression after adjusting for cardiovascular risk factors and history of chemotherapy and radiotherapy. Results There was no association between alcohol consumption and incident CVD among long-term survivors of CRC. Additionally, hazardous alcohol consumption (≥ 40 g/day in male patients and ≥ 20 g/day in female patients) was associated with increased CVD, ischemic stroke, and hemorrhagic stroke (adjusted hazard ratio [95% confidence interval]: 1.51 [1.15–1.97], 1.60 [1.03–2.48], and 2.65 [1.25–5.62], respectively) compared with non-drinkers. Conclusion No discernable protective association was found between alcohol consumption and incident CVD for even light-to-moderate drinking among long-term survivors of CRC. Alcohol consumption ≥40 g/day in male patients and ≥ 20 g/day in female patients was associated with an increased risk of stroke compared with non-drinkers. These novel results provide useful evidence when advising survivors of CRC regarding alcohol use.

Abstract The association of fluctuations in body mass index with cardiovascular risk in long-term is not well understood. This study aimed to investigate cardiovascular outcomes of weight fluctuation. Total of 67,101 obese adults from the Korean National Health Insurance Service who received health examinations in three separate biennial periods were included. Participants were followed up from January 1, 2008 to the date of cardiovascular disease, death, or December 31, 2015, and categorized into 9 distinctive groups according to the BMI. Continuous weight gain showed an increased risk of overall cardiovascular disease (hazard ratio [HR], 2.36; P = 0.007), whereas weight loss after weight maintenance (HR, 0.91; P = 0.016) and weight maintenance after weight loss (HR, 0.91; P = 0.004) were ameliorative compared to the no weight change group. As for coronary heart disease, weight maintenance after weight gain was unfavorable (HR, 1.25; P = 0.004) while weight loss after weight maintenance (HR, 0.82; P

Background The combined associations of physical activity and particulate matter (PM) with subsequent cardiovascular disease (CVD) risk is yet unclear. Methods and Results The study population consisted of 18 846 cancer survivors who survived for at least 5 years after initial cancer diagnosis from the Korean National Health Insurance Service database. Average PM levels for 4 years were determined in administrative district areas, and moderate‐to‐vigorous physical activity (MVPA) information was acquired from health examination questionnaires. A multivariable Cox proportional hazards model was used to evaluate the risk for CVD. Among patients with low PM with particles ≤2.5 µm (PM2.5; (19.8–25.6 μg/m3) exposure, ≥5 times per week of MVPA was associated with lower CVD risk (adjusted hazard ratio [aHR], 0.77; 95% CI, 0.60–0.99) compared with 0 times per week of MVPA. Also, a higher level of MVPA frequency was associated with lower CVD risk (P for trend=0.028) among cancer survivors who were exposed to low PM2.5 levels. In contrast, ≥5 times per week of MVPA among patients with high PM2.5 (25.8–33.8 μg/m3) exposure was not associated with lower CVD risk (aHR, 0.98; 95% CI, 0.79–1.21). Compared with patients with low PM2.5 and MVPA ≥3 times per week, low PM2.5 and MVPA ≤2 times per week (aHR, 1.26; 95% CI, 1.03–1.55), high PM2.5 and MVPA ≥3 times per week (aHR, 1.34; 95% CI, 1.07–1.67), and high PM2.5 and MVPA ≤2 times per week (aHR, 1.38; 95% CI, 1.12–1.70) was associated with higher CVD risk. Conclusions Cancer survivors who engaged in MVPA ≥5 times per week benefited from lower CVD risk upon low PM2.5 exposure. High levels of PM2.5 exposure may attenuate the risk‐reducing effects of MVPA on the risk of CVD.

Abstract Association between body mass index (BMI) and coronary heart disease (CHD) in cancer survivors is not clearly established. This study analyzed the prediagnosis BMI-CHD association by examining 13,500 cancer survivors identified from the National Health Insurance Service-Health Screening Cohort from January 1, 2004 to December 31, 2009 including the patients who were free of cardiovascular disease at enrollment. The Cox proportional hazards model (adjusted for socioeconomic, health behavior, health status, and medical characteristics) was used for calculating hazard ratios (HR) and 95% confidence intervals (95% CI) for CHD in each prediagnosis BMI category among cancer survivors. Compared to cancer survivors with a prediagnosis BMI between 18.5 and 22.9 kg/m2, those with a prediagnosis BMI of 23.0–24.9 kg/m2 and ≥ 25.0 kg/m2 had significantly higher CHD risk (HR = 1.51; 95% CI: 1.13–2.01 and HR = 1.38; 95% CI: 1.04–1.84, respectively). Cancer survivors with a low prediagnosis BMI (

Abstract Background While smoking elevates the risk for cardiovascular disease (CVD) among atrial fibrillation (AF) patients, whether smoking cessation after AF diagnosis actually leads to reduced CVD risk is unclear. We aimed to determine the association of smoking cessation after AF diagnosis with subsequent CVD Risk among South Korean men. Methods This retrospective cohort study included 2372 newly diagnosed AF male patients during 2003–2012 from the Korean National Health Insurance Service database. Self-reported smoking status within 2 years before and after diagnosis date were determined, after which the participants were divided into continual smokers, quitters (smokers who quit after AF diagnosis), sustained-ex smokers (those who quit prior to AF diagnosis), and never smokers. Participants were followed up from 2 years after AF diagnosis until 31 December 2015 for CVD. Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence interval (CIs) for CVD according to the change in smoking habits before and after AF diagnosis. Results The mean (standard deviation, minimum-maximum) age of the study subjects was 62.5 (8.6, 41–89) years. Among AF patients, quitters had 35% reduced risk (aHR 0.65, 95% CI 0.44–0.97) and never smokers had 32% reduced risk (aHR 0.68, 95% CI 0.52–0.90) for CVD compared to continual smokers (p for trend 0.020). Similarly, compared to continual smokers, quitters had 41% risk-reduction (aHR 0.59, 95% CI 0.35–0.99) and never smokers 34% risk-reduction (aHR 0.66, 95% CI 0.46–0.93) for total stroke (p for trend 0.047). Quitters had 50% reduction (aHR 0.50, 95% CI 0.27–0.94), sustained ex-smokers had 36% reduction (aHR 0.64, 95% CI 0.42–0.99), and never smokers had 39% reduction (aHR 0.61, 95% CI 0.41–0.91) in ischemic stroke risk (p for trend 0.047). The risk-reducing effect of quitting on CVD risk tended to be preserved regardless of aspirin or warfarin use. Conclusions Smoking cessation after AF diagnosis was associated with reduced CVD, total stroke, and ischemic stroke risk.