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Abstract We aimed to assess the association of tramadol use with the risk of dementia. This population-based retrospective cohort study using the Korean National Health Insurance Service database included a total of 1,865,827 older adult patients aged 60 years or older with common musculoskeletal pain between January 1, 2003, and December 31, 2007. Individuals who were newly dispensed tramadol (N = 41,963) were identified and propensity score–matched with those who were not (N = 41,963). Over a maximum of 14-year follow-up, the incidence rates (events per 1000 person-years) of all-cause dementia were 6.1 for nonusers, 6.2 for those with cumulative tramadol use of 1–14 days, 7.7 for those with 15–90 days of use, and 8.0 for those with > 90 days of use. Longer cumulative duration of tramadol use was associated with an increased risk of all-cause dementia compared with nonuse (1 to 14 days: aHR 1.06, 95% CI 0.96–1.17; 15 to 90 days: aHR 1.14, 95% CI 1.10–1.35; and more than 90 days: aHR 1.18, 95% CI 1.00–1.39; test for trend: P

Background Sedentary behavior elevates cardiovascular disease (CVD) risk in patients with dyslipidemia. Increasing physical activity (PA) is recommended alongside pharmacological therapy to prevent CVD, though benefits across environmental conditions are unclear. Methods and Results We analyzed data from 113 918 newly diagnosed patients with dyslipidemia (2009–2012) without prior CVD, sourced from the Korea National Health Insurance Service. Ambient particulate matter (PM) 2.5 and PM10 levels were collected from the National Ambient Air Monitoring System in South Korea. Changes in PA, measured in metabolic equivalents of task–min/wk before and after dyslipidemia diagnosis, were evaluated for associations with air pollution levels and CVD risk using Cox proportional hazards regression. Patients were followed from January 1, 2013, until CVD onset, death, or December 31, 2021. Among patients exposed to low to moderate PM2.5 levels (≤25 μg/m3), increasing PA from inactive to ≥1000 metabolic equivalents of tasks–min/wk was associated with a lower risk of CVD (adjusted hazard ratio, 0.82 [95% CI, 0.70–0.97]; P for trend=0.022). In high PM2.5 (>25 μg/m3) conditions, increasing PA from inactive and decreasing PA from ≥1000 metabolic equivalents of task–min/wk was associated with reduced (P for trend=0.010) and elevated (P for trend=0.028) CVD risks, respectively. For PM10, increased PA was linked to reduced CVD risk (P for trend=0.002) and decreased PA to elevated risk (P for trend=0.042) in low to moderate PM10 (≤50 μg/m3) conditions, though benefits diminished at high PM10 (>50 μg/m3) exposures. Conclusions Promoting PA, while considering the high potential cardiovascular risk associated with air pollution, may be an effective intervention against CVD in patients with dyslipidemia.

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

Abstract Background Parental depression is a significant problem that negatively affects parents’ welfare and influences family dynamics, children’s academic and health behaviors, and mental health. However, there is limited evidence regarding the impact of the parental depression into the children’s’ psychological and physical wellbeing on Asian cultures. This study examined the psychological burdens and health behaviors of adolescent children with parents with depression in the Republic of Korea. Methods We conducted a cross-sectional study using data from the Korean National Health and Nutrition Examination Survey (KNHANES) spanning 2013 to 2021 to compare health behaviors and mental health outcomes between 203 adolescent children with parents diagnosed with depression and 3,856 control adolescents aged 12–19 years. Results Following multivariate adjustments, the risk of depressive mood for more than two weeks was significantly increased in boys with parental depression (adjusted Odds Ratio [aOR] = 2.05, 95% Confidence Interval [CI] = 1.91–3.52) and adolescents with parents with moderate-to-severe depression (aOR = 2.60, 95% CI = 1.17–5.77). Adolescents with parental depression reported significantly worse subjective health status (aOR = 1.88, 95% CI = 1.05–3.36) and higher stress levels (aOR = 1.91, 95% CI = 1.33–2.76). Additionally, when parental depression was present and the time since depression diagnosis was more than five years, adolescents with parental depression exhibited even poorer subjective health status and higher stress levels. Conclusions The study found that adolescents whose parents experienced depression had poorer mental health than those whose parents did not have mental health issues. These findings emphasize the importance of providing support for the mental health of adolescents in families affected by parental depression.

Background: Although one of the characteristics of COVID-19 is accompanied by acute pneumonia immediately after infection, large-scale cohort studies focused on this issue are lacking. In addition, there is interest in how COVID-19 vaccinations reduce the incidence of acute pneumonia for people infected with different strains of SARS-CoV-2. Thus, we assess the short-term incidence of pneumonia after COVID-19 with the vaccination and SARS-CoV-2 variants. Methods: As data for 2136,751 COVID-19 patients between January 01, 2020 and February 28, 2022 was collected, they were observed for one month from the day of infection. Patients in retrospective cohort study were classified according to doses of the received vaccine and the epidemic phase when SARS-CoV-2 variants prevailed. Multivariable logistic regression analysis calculated adjusted odds ratios (aOR) and 95% confidence intervals (CIs) for the pneumonia risk. Results: In B.1.1.7-B.1.351, B.1.617.2, and B.1.617.2 variants, the aORs (95% CIs; p-value) for incidence of pneumonia were 0.93 (0.89–0.98;

Abstract Recent studies elucidate that coronavirus disease 2019 (COVID‐19) patients may face a higher risk of cardiovascular complications. This study aimed to evaluate association of COVID‐19 with the risk of pulmonary embolism (PE) or deep vein thrombosis (DVT). This nationwide population‐based retrospective cohort study included Korean adult citizens between January 2021 and March 2022 from the Korea Disease Control and Prevention Agency COVID‐19 National Health Insurance Service cohort. The Fine and Gray's regression with all‐cause death as a competing event was adopted to evaluate PE and DVT risks after COVID‐19. This study included a total of 1,601,835 COVID‐19 patients and 14,011,285 matched individuals without COVID‐19. The risk of PE (adjusted hazard ratio [aHR], 6.25; 95% confidence interval [CI], 3.67–10.66; p

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: The association of allergic diseases such as allergic rhinitis, asthma, and atopic dermatitis with Parkinson's disease (PD) risk is yet unclear. In the few preceding studies, a short follow-up duration was followed for a relatively small study population, and lifestyle behaviors were not adjusted for. Therefore, there is a need for large-scale observation studies on the association of allergic disease with PD risk after considering lifestyle behaviors. Methods: The study population consisted of 398,936 participants aged 40 years or older who underwent health screening before 1 January 2005 from the Korean National Health Insurance Service database. Starting from 1 January 2005, all participants were followed up until the date of PD event, death, or 31 December 2019. The adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the risk of PD were calculated using multivariable Cox proportional hazards regression. Results: Compared to non-allergic disease participants, allergic disease patients had a higher risk for PD (aHR 1.18, 95% CI 1.07–1.30) and especially, allergic rhinitis patients had a higher risk for PD (aHR 1.14, 95% CI 1.00–1.29). Allergic disease was associated with a higher risk for PD (aHR 1.24, 95% CI 1.01–1.52) among participants who were never smokers, did not consume alcohol, and exercised regularly. Conclusions: Allergic rhinitis was associated with a higher risk for PD compared to participants without allergic rhinitis. This risk-increasing association of allergic rhinitis with PD was preserved even among people with healthy lifestyle behaviors.

Abstract Background An association between sleep behaviors and muscle-fat mass is continuously interesting topic. Methods Based on the survey on sleep behaviors (quality and duration), the poor quality of sleep was evaluated when the subject did not feel satisfied after sleep, while the good quality was evaluated as they feel refreshed. A total of 19,770 participants were divided into the four groups according to changes in sleep quality: Good-to-Good (those who continuously maintained good quality), Good-to-Poor (those who reported initial good quality but subsequently reported a poor quality), Poor-to-Poor (those who continuously maintained poor quality), and Poor-to-Good (those who reported improved quality of sleep). As changes in skeletal muscle and fat mass index [kg/m2] were estimated by a validated prediction equation, multiple linear regression was used to calculate adjusted mean (adMean) of muscle and fat mass according to changes in sleep behavior. Results When sleep duration decreased and quality of sleep deteriorated (from good to poor), fat mass index significantly increased (adMean: 0.087 for the Good-to-Good group and 0.210 for the Good-to-Poor group; p-value = 0.006). On the other hand, as the quality of sleep deteriorated, skeletal muscle mass more decreased despite the maintained sleep duration (adMean: -0.024 for the Good-to-Good group and − 0.049 for the Good-to-Poor group; p-value = 0.009). Conclusion Our results showed that changes in sleep quality and duration affect changes in muscle and fat mass. Thus, we suggest maintaining a good quality of sleep, even if sleep duration is reduced, to preserve muscle mass and inhibit the accumulation of fat.

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 Background High-density lipoprotein cholesterol’s (HDL-C) long-held status as a cardiovascular disease (CVD) preventative has been called into question. Most of the evidence, however, focused on either the risk of death from CVD, or on single time point level of HDL-C. This study aimed to determine the association between changes in HDL-C levels and incident CVD in individuals with high baseline HDL-C levels (≥ 60 mg/dL). Methods 77,134 people from the Korea National Health Insurance Service-Health Screening Cohort were followed for 517,515 person-years. Cox proportional hazards regression was used to evaluate the association between change in HDL-C levels and the risk of incident CVD. All participants were followed up until 31 December 2019, CVD, or death. Results Participants with the greatest increase in their HDL-C levels had higher risks of CVD (adjusted hazard ratio [aHR], 1.15; 95% confidence interval [CI], 1.05–1.25) and CHD (aHR 1.27, CI 1.11–1.46) after adjusting for age, sex, household income, body mass index, hypertension, diabetes mellitus, dyslipidemia, smoking, alcohol consumption, moderate-to-vigorous physical activity, Charlson comorbidity index, and total cholesterol than those with the lowest increase in HDL-C levels. Such association remained significant even among participants with decreased low-density lipoprotein cholesterol (LDL-C) levels for CHD (aHR 1.26, CI 1.03–1.53). Conclusions In people with already high HDL-C levels, additional increases in HDL-C levels may be associated with an increased risk of CVD. This finding held true irrespective of the change in their LDL-C levels. Increasing HDL-C levels may lead to unintentionally elevated risk of CVD.

Introduction This study investigated the association between smoking types, including dual use (usage of both combustible cigarettes and e-cigarettes), and non-alcoholic fatty liver disease (NAFLD) status in Korean men. Methods Data from the 7th and 8th Korea National Health and Nutrition Examination Survey (KNHANES) 2016–2020 were used. The presence of NAFLD was defined by the respective cut-off values for the Hepatic Steatosis Index (HSI), NAFLD Ridge Score (NRS), and Korea National Health and Nutrition Examination Survey NAFLD score (KNS). Multivariate logistic regression analyses were used to determine the associations between smoking types and NAFLD as determined by HSI, NRS, and KNS. Results After adjustment for confounders, an independent association was observed between dual use and NAFLD (HSI: AOR=1.47; 95% CI: 1.08–1.99, p=0.014; NRS: AOR=2.21; 95% CI: 1.70–2.86, p=0.000; KNS: AOR=1.35; 95% CI: 1.01– 1.81, p=0.045). Cigarette only smokers also had significantly higher odds of NAFLD compared to never smokers for all of the NAFLD indices (HSI: AOR=1.22; 95% CI: 1.05–1.42, p=0.008; NRS: AOR=2.13; 95% CI: 1.87–2.42, p=0.000; KNS: AOR=1.33; 95% CI: 1.14–1.55, p=0.000). In subgroup analyses, no significant interaction effects were found for age, BMI, alcohol consumption, income, physical activity, and the diagnosis of T2DM. Moreover, cigarette only smokers and dual users differed significantly in terms of log-transformed urine cotinine and packyears. The relationship between smoking type and pack-years was attenuated after stratification by age. Conclusions This study shows that the dual use of e-cigarettes and combustible cigarettes is associated with NAFLD. Age differences may explain why dual users, with a greater proportion of young people, appear to have fewer pack-years than cigarette only smokers. Further research should be conducted to investigate the adverse effects of dual use on hepatic steatosis.

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.

Introduction Several studies have reported that exposure to antibiotics can lead to asthma during early childhood. However, the association between antibiotic use and risk of asthma in the adult population remains unclear. This study aimed to investigate the association between antibiotic use and asthma in adults.Methods We used data from the National Health Insurance Service (NHIS)-Health Screening Cohort, which included participants aged ≥40 years who had health screening examination data in 2005–2006. A total of 248 961 participants with a mean age of 55.43 years were enrolled in this retrospective cohort study. To evaluate antibiotic exposure from the NHIS database for 5 years (2002–2006), cumulative usage and multiclass prescriptions were identified, respectively. During the follow-up period (2007–2019), 42 452 patients were diagnosed with asthma. A multivariate Cox proportional hazard regression model was used to assess the association between antibiotic use and newly diagnosed asthma.Results Participants with antibiotic use for ≥91 days showed a higher risk of asthma (adjusted HR (aHR) 1.84, 95% CI 1.72 to 1.96) compared with participants who did not use antibiotics (n=38 450), with a duration-dependent association (ptrend

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 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.

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.

We evaluated the diagnostic and clinical usefulness of blood specimens to detect Middle East respiratory syndrome coronavirus infection in 21 patients from the 2015 outbreak in South Korea. Viral RNA was detected in blood from 33% of patients at initial diagnosis, and the detection preceded a worse clinical course.

As the main symptom of Alzheimer’s disease-related dementia is memory loss, patient compliance for donepezil hydrochloride (donepezil), administered as once-daily oral formulations, is poor. Thus, we aimed to design poly(lactic-co-glycolic acid) (PLGA) microspheres (MS) with alginate-coated large pores as an injectable depot of donepezil exhibiting sustained release over 2–3 weeks. The PLGA MS with large pores could provide large space for loading drugs with high loading capacity, and thereby sufficient amounts of drugs were considered to be delivered with minimal use of PLGA MS being injected. However, initial burst release of donepezil from the porous PLGA MS was observed. To reduce this initial burst release, the surface pores were closed with calcium alginate coating using a spray-ionotropic gelation method. The final pore-closed PLGA MS showed in vitro sustained release for approximately 3 weeks, and the initial burst release was remarkably decreased by the calcium alginate coating. In the prediction of plasma drug concentration profiles using convolution method, the mean residence time of the pore-closed PLGA MS was 2.7-fold longer than that of the porous PLGA MS. Therefore, our results reveal that our pore-closed PLGA MS formulation is a promising candidate for the treatment of dementia with high patient compliance.

Phasmatodea, commonly known as stick insects, are recognized as noteworthy pests globally, impacting agriculture and forest ecosystems. Among them, the outbreak of Ramulus mikado has emerged as a notable concern in East Asian forests. Recently, Metarhizium phasmatodeae has been identified as utilizing stick insects as hosts. We have observed evidence of this entomopathogenic fungus infecting stick insects. Given the increase in these occurrences during the rainy period, this study investigated the relationship between the survival of R. mikado and the M. phasmatodeae infection during the rainy seasons of 2022 and 2023. We collected stick insects in two representative forests of the Republic of Korea and examined insect survival, fungal infection, and various environmental factors. No infections were detected in specimens collected in June before the rainy season, but from July onwards, both the mortality of R. mikado and the fungal infection substantially increased. By the last sampling date of each year, 75% (2022), 71.4% (2023) of the specimens were infected, and over 90% of the total individuals succumbed as a result. Fungi isolated from deceased R. mikado were successfully identified as M. phasmatodeae using morphological and taxonomic approaches. Various statistical analyses, including principal component analysis and modeling, revealed a robust association between fungal infection and the survival of stick insects. The results highlight the correlation between mass deaths of stick insects and fungal infection, particularly during the summer rainy season. These findings offer valuable insights for forecasting R. mikado population in the upcoming year and developing effective pest control strategies. [ABSTRACT FROM AUTHOR]

The genus Bryaxis Kugelann (Goniaceritae: Bythinini) is the most species-rich genus of the subfamily Pselaphinae and is mainly distributed in the Palearctic region. Although previous studies have documented 14 species in the Korean Peninsula, the true diversity, ecology, and immature stages of the genus are still inadequately known. In this study, five new Korean species are described: B. grandinodus sp. nov., B. uljinensis sp. nov., B. fabaiformis sp. nov., B. girinensis sp. nov., and B. nemorosus sp. nov. Illustrations of the habitus and other morphological details, and a distribution map are provided. In addition, Bryaxis leechanyoungi Nomura & Lee, 1993 is proposed as a new synonym of B. mahunkai Löbl, 1975 based on the original description and illustrations of diagnostic characters. [ABSTRACT FROM AUTHOR]

The article introduces a novel direct photocatalytic patterning method that maintains the optical properties of perovskite nanocrystals (PeNCs) and other emissive nanomaterials. This technique uses a photoinduced thiol-ene click reaction involving specially designed surface ligands and a dual-role photocatalytic reagent, resulting in high-resolution patterns of PeNCs while also enhancing their photoluminescence quantum yield and photostability.