Effects and safety of transcranial direct current stimulation on multiple health outcomes: an umbrella review of randomized clinical trials.

Transcranial direct current stimulation (tDCS), which delivers a direct current to the brain, emerged as a non-invasive potential therapeutic in treating a range of neurological and neuropsychiatric disorders. However, a comprehensive quantitative evidence synthesis on the effects of tDCS on a broad range of mental illnesses is lacking. Here, we systematically assess the certainty of the effects and safety of tDCS on several health outcomes using an umbrella review of randomized controlled trials (RCTs). The methodological quality of each included original meta-analysis was assessed by the A Measurement Tool for Assessing Systematic Reviews 2 (AMSTAR2), and the certainty of the evidence for each effect was evaluated with Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). We followed an a priori protocol (PROSPERO CRD42023458700). We identified 15 meta-analyses of RCTs (AMSTAR 2; high 3, moderate 3, and low 9) that included 282 original articles, covering 22 unique health endpoints across 22 countries and six continents. From meta-analyses of RCTs supported by very low to high certainty of evidence, it was found that tDCS improved symptoms related to post-stroke, including post-stroke depression scale score (equivalent standardized mean difference [eSMD], 1.61 [95% confidence level, 0.72-2.50]; GRADE=moderate), activities of daily living independence (7.04 [3.41-10.67]; GRADE=high), motor recovery of upper and lower extremity (upper extremity: 0.15 [0.06-0.24], GRADE=high; lower extremity: 0.10 [0.03-0.16], GRADE=high), swallowing performance (GRADE=low), and spasticity (GRADE=moderate). In addition, tDCS had treatment effects on symptoms of several neurological and neuropsychiatric disorders, including obsessive-compulsive disorder (0.81 [0.44-1.18]; GRADE=high), pain in fibromyalgia (GRADE=low), disease of consciousness (GRADE=low), insight score (GRADE=moderate) and working memory (0.34 [0.01-0.67]; GRADE=high) in schizophrenia, migraine-related pain (-1.52 [-2.91 to -0.13]; GRADE=high), attention-deficit/hyperactivity disorder (reduction in overall symptom severity: 0.24 [0.04-0.45], GRADE=low; reduction in inattention: 0.56 [0.02-1.11], GRADE=low; reduction in impulsivity: 0.28 [0.04-0.51], GRADE=low), depression (GRADE=low), cerebellar ataxia (GRADE=low), and pain (GRADE=very low). Importantly, tDCS induced an increased number of reported cases of treatment-emergent mania or hypomania (0.88 [0.62-1.13]; GRADE=moderate). We found varied levels of evidence for the effects of tDCS with multiple neurological and neuropsychiatric conditions, from very low to high certainty of evidence. tDCS was effective for people with stroke, obsessive-compulsive disorder, fibromyalgia, disease of consciousness, schizophrenia, migraine, attention-deficit/hyperactivity disorder, depression, cerebellar ataxia, and pain. Therefore, these findings suggest the benefit of tDCS for several neurological and neuropsychiatric disorders; however, further studies are needed to understand the underlying mechanism and optimize its therapeutic potential.

Clinical characteristics and outcomes of patients with mpox during the 2022 mpox outbreak compared with those before the outbreak: A systematic review and meta-analysis.

On 23 July 2022, the World Health Organization declared the global mpox outbreak as a public health emergency of international significance. The mpox virus (MPXV) that caused the outbreak was classified as clade IIb, which belongs to the West African clade. However, the relationship between MPXV clades and symptoms, as well as the severity of mpox outcomes, is not fully understood. Thus, we aimed to investigate the global mpox prevalence and the differences in clinical manifestations and outcomes among patients with mpox between pre-outbreak (2003-2021) and the current mpox outbreak. In this systematic review and meta-analysis, PubMed/MEDLINE, Web of Science, Embase, Cumulative Index to Nursing and Allied Health Literature, and Google Scholar were searched using the keyword "monkeypox" and "mpox" up to 13 October 2022. A random effects model was used to obtain the pooled prevalence and 95% confidence intervals. This study included 27 articles, and 5698 patients with mpox with 19 distinctive features from 19 countries across five continents were assessed. Patients with mpox during the 2022 mpox outbreak showed mild clinical manifestations and outcomes compared with those before the 2022 mpox outbreak: mild rash (relative ratio [RR]: 5.09, 95% confidence interval [CI]: 1.52-17.08), fever (0.68, 0.49-0.94), pruritus (0.25, 0.19-0.32), myalgia (0.50, 0.31-0.81), headache (0.56, 0.35-0.88), skin ulcer (0.32, 0.17-0.59), abdominal symptom (0.29, 0.20-0.42), pharyngitis (0.32, 0.18-0.58), nausea or vomiting (0.15, 0.02-0.93), conjunctivitis (0.11, 0.03-0.38), concomitant infection with HIV (1.70, 0.95-3 0.04), and death (0.02, 0.001-0.31). MPXV clade IIb exhibited higher infectivity but may cause mild disease symptoms and low mortality rate. It is important to consider MPXV infection in patients with mpox-related features and/or a history of sexual transmission to prevent the spread of the disease and recognise the current pandemic threat.

Risks of cutaneous immune-related adverse events in long COVID: Multinational cohort studies in South Korea, Japan, and the UK.

Previous research has not investigated the persistent cutaneous immune-related adverse events (cirAEs) related to long COVID to investigate the long-term sequelae. This multinational study, using a propensity-matched overlap weighting method, utilizes large national claims-based cohorts, using ICD-10 code diagnosis, focusing on patients aged ≥20 years from three countries: South Korean, Japanese, and the British cohorts. To estimate the risk of cirAEs in long COVID, the persistence or emergence of cirAEs occurring 4 weeks after the initial SARS-CoV-2 infection, we employed a Cox proportional hazard regression model. The Korean cohort (n = 5,937,373; mean age 49.2 years [SD: 13.2]), the Japanese cohort (n = 4,307,587; 42.5 years [13.6]), and the UK cohort (n = 395,435; 71.0 years [8.07]) were presented. An increased risk of cirAEs in long COVID was observed (HR, 1.10; 95% CI, 1.06-1.14) in Korean cohort, while a similar association was observed in Japanese and UK cohorts. The long-term risk of cirAEs in long COVID was higher in more severe COVID-19 cases (1.31; 1.22-1.39). Unlike the increased risk of cirAEs in long COVID, COVID-19 vaccination attenuated the risk, especially with two or more doses (1.03; 0.95-1.11) or heterologous regimens (0.98; 0.76-1.27). The time attenuation effect indicated a sustained risk for up to 6 months postinfection (<3 months: 1.13 [1.07-1.19]; 3-6 months: 1.14 [1.06-1.22]). SARS-CoV-2 infection is associated with an increased risk of cirAEs in the aspect of long COVID. Vaccination might reduce this risk, highlighting the need for preventive strategies in long COVID management.

National Trends in Allergic Rhinitis and Chronic Rhinosinusitis and COVID-19 Pandemic-Related Factors in South Korea, from 1998 to 2021.

INTRODUCTION: Existing studies provide insights into the prevalence and environmental factors associated with allergic rhinitis (AR) and chronic rhinosinusitis (CRS) globally. However, limitations still persist in these studies, particularly regarding cohort sizes and the duration of follow-up periods, indicating a need for more comprehensive and long-term research in these fields. Our study aimed to investigate the prevalence, long-term trends, and underlying factors of these conditions in the general population of adult participants (≥19 years) in Korea. METHOD: We analyzed data from adult participants (≥19 years) from the Korea National Health and Nutrition Examination Survey (KNHANES) study to determine the prevalence of AR and CRS from 1998 to 2021. To analyze prevalence trends before and during the COVID-19 pandemic, we employed a weighted linear regression model and obtained ß-coefficients with 95% confidence intervals (CI). RESULTS: Between 1998 and 2021, over a span of 24 years, the comprehensive KNHANES study included 146,264 adult participants (mean age: 47.80 years, standard deviation: 16.49 years; 66,177, 49.3% men). The prevalence of AR and CRS increased from 1998 to 2021, with AR prevalence rising from 5.84% (95% CI, 5.57-6.10) in 1998-2005 to 8.99% (8.09-9.91) in 2021 and CRS from 1.84% (1.70-1.97) in 1998-2005 to 3.70% (3.18-4.23) in 2021. However, the increasing trend has slowed down during the COVID-19 pandemic era. CONCLUSIONS: The significance of continuous monitoring and focused interventions for AR and CRS is underscored by this study. The observed deceleration in the rising prevalence of AR and CRS during the pandemic indicates the possibility of beneficial impacts from lifestyle modifications triggered by the pandemic. These findings call for additional research to explore potential protective effects in greater depth.

National Trends and Prevalence of Atopic Dermatitis and Pandemic-Related Factors among Korean Adults, 2007-2021.

INTRODUCTION: Previous studies have variably reported inconclusive trends in the prevalence of atopic dermatitis (AD) among adults, and there are limited data on the impact of the COVID-19 pandemic. We aimed to investigate the national trends and age-stratified prevalence of AD among adults from 2007 to 2021 in South Korea, focusing mainly on the impact of the COVID-19 pandemic-related factors. METHODS: A nationwide cross-sectional study was conducted using the Korea National Health and Nutrition Examination Survey data from 2007 to 2021. Overall and age-stratified prevalence for AD were assessed using weighted beta coefficients or odds ratios. RESULTS: A total of 83,566 adults over 20 years (male, 49.40%) were included. During the observation period, the prevalence of AD was stable in the overall population from 2.61% (95% CI, 2.29-2.93) in 2007-2009 to 2.15% (1.68-2.63) in 2020 and 2.38% (1.81-2.95) in 2021. However, the weighted prevalence of AD in adults aged 40-59 years old decreased during the pre-pandemic era, and the prevalence of AD in adults aged above 60 years significantly decreased during the pandemic, with a significant decline observed after the initial outbreak. From age-stratification analysis, the adults aged 40-59 years showed a significant increase after the pandemic outbreak which was evident in specific variables: individuals with rural residence, lower education, and lower household income quartiles. Adults aged above 60 years showed a significant decrease in the slope after the outbreak, evident in specific variables: individuals of female, rural residence, lower education, and lower household income quartiles. CONCLUSION: We observed a stable overall prevalence of AD throughout the 15-year observation period. However, the age-stratified analysis suggested significantly different trends according to age-stratified groups and the impact of the COVID-19 pandemic on the prevalence of AD.

Prenatal and postnatal exposure to antibiotics and risk of food allergy in the offspring: A nationwide birth cohort study in South Korea.

BACKGROUND: There are only preliminary studies examining the associations of postnatal antibiotic exposure with food allergy in childhood, and the effect of antibiotic exposure in utero has not been resolved. Thus, we aimed to investigate the effect of prenatal and postnatal antibiotic exposure on the risk of food allergy in childhood. METHODS: Using the nationwide birth cohort in South Korea, all 3,163,206 infants (pairing mother; n = 2,322,735) born in South Korea between 2010 and 2017 were included in the analysis. The primary outcome was the diagnosis of food allergy, and the observation period was between January 1, 2009, and December 31, 2020. We implemented four different designs for the study, which consisted of a full unmatched cohort, 1:1 propensity-matched cohort, sibling comparison cohort, and health screening cohort along with multiple subgroup analyses. RESULTS: During the follow-up period (median 6.92 years [IQR, 4.72-9.00]) of the 3,161,858 infants (52.6% male) in the birth cohort, 29,973 (1.9%) were diagnosed with food allergies. After a 1:1 propensity score matching, the use of antibiotics increased the risk of overall food allergy (prenatal [HR, 1.05; 95% CI, 1.04-1.09] and postnatal [HR, 1.05; 95% CI, 1.01-1.10] periods). The association was more significantly accentuated when antibiotic exposure was used in the short term, and the children were born preterm or with low birthweight; however, a trimester-specific effect was not observed. We observed more pronounced risks of food allergy in the health screening cohort (prenatal, 17%; postnatal, 15%), thus addressing the adverse effects of critical factors including maternal BMI, smoking status, and type of infant feeding. Similar trends were observed across all four differnt cohorts. CONCLUSION: This study reported a moderate association between early-life antibiotic use and subsequent food allergy during childhood throughout four different designs of analyses. This study suggests that clinicians need to consider the risks and benefits of antibiotics when administering antibiotics to individuals in the prenatal and postnatal periods.

Incident allergic diseases in post-COVID-19 condition: multinational cohort studies from South Korea, Japan and the UK.

As mounting evidence suggests a higher incidence of adverse consequences, such as disruption of the immune system, among patients with a history of COVID-19, we aimed to investigate post-COVID-19 conditions on a comprehensive set of allergic diseases including asthma, allergic rhinitis, atopic dermatitis, and food allergy. We used nationwide claims-based cohorts in South Korea (K-CoV-N; n = 836,164; main cohort) and Japan (JMDC; n = 2,541,021; replication cohort A) and the UK Biobank cohort (UKB; n = 325,843; replication cohort B) after 1:5 propensity score matching. Among the 836,164 individuals in the main cohort (mean age, 50.25 years [SD, 13.86]; 372,914 [44.6%] women), 147,824 were infected with SARS-CoV-2 during the follow-up period (2020-2021). The risk of developing allergic diseases, beyond the first 30 days of diagnosis of COVID-19, significantly increased (HR, 1.20; 95% CI, 1.13-1.27), notably in asthma (HR, 2.25; 95% CI, 1.80-2.83) and allergic rhinitis (HR, 1.23; 95% CI, 1.15-1.32). This risk gradually decreased over time, but it persisted throughout the follow-up period (≥6 months). In addition, the risk increased with increasing severity of COVID-19. Notably, COVID-19 vaccination of at least two doses had a protective effect against subsequent allergic diseases (HR, 0.81; 95% CI, 0.68-0.96). Similar findings were reported in the replication cohorts A and B. Although the potential for misclassification of pre-existing allergic conditions as incident diseases remains a limitation, ethnic diversity for evidence of incident allergic diseases in post-COVID-19 condition has been validated by utilizing multinational and independent population-based cohorts.

National prevalence of smoking among adolescents at tobacco tax increase and COVID-19 pandemic in South Korea, 2005-2022.

Prior research has predominantly focused on the overall effects of the tobacco tax increase and the COVID-19 pandemic on adolescent smoking behavior. However, there is a need to examine both the immediate and sustained associations of these two factors on subgroups of adolescents, employing an interrupted time-series model. We aimed to investigate the immediate and sustained association of tobacco tax increase and the COVID-19 pandemic on adolescent smoking prevalence. This study utilized data from the Korea Youth Risk Behavior Web-Based Survey to analyze the prevalence of current smoking among all participants (CSP) and the prevalence of daily smoking among current smokers (DSP) of Korean adolescents (n = 1,159,995; mean, age 14.99; male 51.5%) over 18 years from 2005 to 2022. The study examined 18-year trends in CSP and DSP among Korean adolescents, emphasizing the influences of the 2015 tobacco tax increase and the COVID-19 pandemic, using ß coefficients and their differences (ßdiff) from an interrupted time-series ARIMA model. While CSP exhibited a decreasing trend, DSP exhibited an increasing trend. Tobacco tax increase was associated with both the short and long terms in smoking prevalence, however, the short-term association on prevalence (CSP, - 3.076 [95% CI, - 3.707 to - 2.445]; DSP, - 4.112 [95% CI, - 6.488 to - 1.735]) was stronger. The pandemic was associated with an immediate increase in DSP (9.345 [95% CI, 5.285-13.406]). These effects were strongest among adolescents from low economic status and those exposed to familial secondhand smoking. Supportive programs for adolescents in low-income families will help overcome the effects associated with the pandemic. As a tobacco tax increase was associated with a reduction in smoking prevalence, this could be one method to overcome the effects of the pandemic.

Acute and post-acute respiratory complications of SARS-CoV-2 infection: population-based cohort study in South Korea and Japan.

Considering the significant burden of post-acute COVID-19 conditions among patients infected with SARS-CoV-2, we aimed to identify the risk of acute respiratory complications or post-acute respiratory sequelae. A binational population-based cohort study was conducted to analyze the risk of acute respiratory complications or post-acute respiratory sequelae after SARS-CoV-2 infection. We used a Korean nationwide claim-based cohort (K-COV-N; n = 2,312,748; main cohort) and a Japanese claim-based cohort (JMDC; n = 3,115,606; replication cohort) after multi-to-one propensity score matching. Among 2,312,748 Korean participants (mean age, 47.2 years [SD, 15.6]; 1,109,708 [48.0%] female), 17.1% (394,598/2,312,748) were infected with SARS-CoV-2. The risk of acute respiratory complications or post-acute respiratory sequelae is significantly increased in people with SARS-CoV-2 infection compared to the general population (acute respiratory complications: HR, 8.06 [95% CI, 6.92-9.38]; post-acute respiratory sequelae: 1.68 [1.62-1.75]), and the risk increased with increasing COVID-19 severity. We identified COVID-19 vaccination as an attenuating factor, showing a protective association against acute or post-acute respiratory conditions. Furthermore, while the excess post-acute risk diminished with time following SARS-CoV-2 infection, it persisted beyond 6 months post-infection. The replication cohort showed a similar pattern in the association. Our study comprehensively evaluates respiratory complications in post-COVID-19 conditions, considering attenuating factors such as vaccination status, post-infection duration, COVID-19 severity, and specific respiratory conditions.

Prenatal and infant exposure to antibiotics and subsequent risk of neuropsychiatric disorders in children: A nationwide birth cohort study in South Korea.

We aimed to assess the association between antibiotic exposure in fetal and postnatal life (within six months after birth) and the risk of neuropsychiatric disorders in childhood. A nationwide, population-based birth cohort study(infants, n = 3,163,206; paired mothers, n = 2,322,735) was conducted in South Korea, with a mean follow-up duration of 6.8 years, using estimates of hazard ratio [HR] and 95 % confidence intervals (CIs). Following propensity score matching including the baseline variables, antibiotic exposure in both fetal (HR,1.07 [95 % CI, 1.05-1.08]) and postnatal life (1.05 [1.03-1.07]) was associated with an increased risk of overall childhood neuropsychiatric disorders. A synergistic effect was observed with prenatal and postnatal exposures (1.12 [1.09-1.15]). The risk increases with the increasing number and duration of prescriptions. Significant associations were found for both common (1.06 [1.05-1.08]) and severe outcomes (1.17 [1.09-1.26]), especially for intellectual disability (1.12 [1.07-1.17]), ADHD (1.10 [1.07-1.13]), anxiety (1.06 [1.02-1.11]), mood (1.06 [1.00-1.12]), and autism (1.03 [1.01-1.07]). When comparing siblings with different exposure statuses to consider familial factors, prenatal and postnatal exposure risk increased to 10 % (95 % CI, 6-12) and 12 % (7-17), respectively. Similar results were observed in the unmatched and health screening cohort, which considers maternal obesity, smoking, and breastfeeding. Based on these findings, clinicians may consider potential long-term risks when assessing the risk-benefit of early-life antibiotic prescription.

Global trends in incidence and prevalence of achalasia, 1925-2021: A systematic review and meta-analysis.

BACKGROUND: Achalasia poses a significant socioeconomic burden, yet global trends remain undocumented. This study aims to describe the worldwide trends in the incidence and prevalence of achalasia from 1925 to 2021 and explore their correlation with various factors through a comprehensive systematic review. METHODS: We searched the PubMed/MEDLINE, Embase, and Cochrane databases from inception to 30 June 2023, to identify studies reporting the incidence or prevalence of achalasia in the general population. This study utilized pooled estimates with 95% confidence intervals (CI) to estimate the incidence and prevalence of achalasia, and conducted various subgroup analyses. RESULTS: A total of 26 eligible studies covering approximately 269 million participants and 20,873 patients from 14 countries across five continents were included. Global pooled incidence and prevalence of achalasia were estimated to be 0.78 cases per 100,000 person-years (95% CI, 0.64-0.93; number of studies, 26; sample population, 269,315,171) and 10.82 cases per 100,000 person-years (95% CI, 8.15-13.48; number of studies, 14; sample population, 192,176,076), respectively. The incidence of achalasia was higher in Oceania (than Asia and Africa) and in adults (than children) after the introduction of the Chicago classification. Prevalence followed a similar pattern. The pooled incidence of achalasia showed an overall upward trend from 1925 to 2021 (1925-1999; 0.40 [0.32-0.49] vs. 2018-2021; 1.64 [1.33-1.95] cases per 100,000 person-years). CONCLUSIONS: The incidence and prevalence of achalasia have notably increased, particularly with advancements in diagnosis, and show significant variation worldwide, despite the large heterogeneity within the sample population. Further studies are necessary to accurately assess the global incidence and prevalence of achalasia.

Prediction model for cardiovascular disease in patients with diabetes using machine learning derived and validated in two independent Korean cohorts.

This study aimed to develop and validate a machine learning (ML) model tailored to the Korean population with type 2 diabetes mellitus (T2DM) to provide a superior method for predicting the development of cardiovascular disease (CVD), a major chronic complication in these patients. We used data from two cohorts, namely the discovery (one hospital; n = 12,809) and validation (two hospitals; n = 2019) cohorts, recruited between 2008 and 2022. The outcome of interest was the presence or absence of CVD at 3 years. We selected various ML-based models with hyperparameter tuning in the discovery cohort and performed area under the receiver operating characteristic curve (AUROC) analysis in the validation cohort. CVD was observed in 1238 (10.2%) patients in the discovery cohort. The random forest (RF) model exhibited the best overall performance among the models, with an AUROC of 0.830 (95% confidence interval [CI] 0.818-0.842) in the discovery dataset and 0.722 (95% CI 0.660-0.783) in the validation dataset. Creatinine and glycated hemoglobin levels were the most influential factors in the RF model. This study introduces a pioneering ML-based model for predicting CVD in Korean patients with T2DM, outperforming existing prediction tools and providing a groundbreaking approach for early personalized preventive medicine.

National trends in sexual intercourse and usage of contraception among Korean adolescents.

BACKGROUND: The exact influence of the COVID-19 pandemic on sexual intercourse and usage of contraception remains largely uncharted territory. To bridge this gap in knowledge, we conducted a comprehensive, cross-sectional examination of long-term trends in the prevalence of sexual intercourse and usage of contraception among South Korean adolescents from 2006 to 2022. METHODS: In our research, we drew upon data encompassing 1,138,799 South Korean adolescents aged 12 to 18 years, derived from the Korean Youth Risk Behavior Web-based Survey (KYRBS) over a period spanning from 2006 to 2022. We focused on the prevalence of sexual intercourse, contraception utilization, and the underlying associated factors among this demographic. The KYRBS data was collected using a complex sampling strategy to determine the national prevalence estimates and shifts in prevalence before (2006-2019) and during (2020-2022) the COVID-19 pandemic era. RESULTS: During the pre-pandemic period, a decrease in adolescent sexual intercourse was observed (6.34% in 2006, 5.53% in 2012, and 5.87% in 2019). However, in the post-pandemic period (2020-2022), there was a surge in sexual intercourse (4.55% in 2020 and 6.20% in 2022). This evident alteration in sexual intercourse trajectory between pre- and post-pandemic periods was statistically significant [ßdiff, 0.950; 95% confidence interval (CI), 0.756-1.144]. Regarding contraceptive use among South Korean adolescents, there was an increase in the pre-COVID-19 pandemic phase across all demographic segments (14.61% in 2006, 22.30% in 2012, and 47.69% in 2022) but a notable decline when compared with the pre- and post-pandemic periods (ßdiff, - 0.319; 95% CI, - 0.454 to - 0.184). Additionally, during the study period, a decrease in sexual intercourse was observed in the pre-pandemic period (ß, - 0.129; 95% CI, - 0.148 to - 0.110), followed by an increase in the post-pandemic period (ß, 0.821; 95% CI, 0.627 to 1.014). This shift is highlighted by an effect size of 0.96 [weighted odds ratio (wOR); 95% CI, 0.92 to 1.00], indicating a substantial change in adolescent sexual behaviors across study periods. CONCLUSIONS: The increase in sexual intercourse and decrease in usage of contraception observed in our study between the pre- and post-COVID-19 periods suggests a potential threat to sexual health among South Korean adolescents. This trend emphasizes the ongoing necessity of raising awareness about adolescent sexual behavior in South Korea.

Long-term gastrointestinal and hepatobiliary outcomes of COVID-19: a multi-nationwide cohort study from South Korea, Japan, and the UK.

Background/Aims: Considering emerging evidence on long COVID, comprehensive analyses of the post-acute complications of long COVID in the gastrointestinal and hepatobiliary systems are needed. We aimed to investigate the impact of COVID-19 on the long-term risk of gastrointestinal and hepatobiliary outcomes and other digestive abnormalities in various follow-up periods. Methods: We used three large-scale population-based cohorts: the Korean cohort (discovery cohort), the Japanese cohort (validation cohort-A), and the UK Biobank (validation cohort-B). 10,027,506 Korean, 12,218,680 Japanese, and 468,617 UK patients aged ≥20 years, including those with SARS-CoV-2 infection between 2020 and 2021 matched to non-infected control patients. Seventeen gastrointestinal and eight hepatobiliary outcomes as well as nine other digestive abnormalities following SARS-CoV-2 infection were identified and compared with contemporary controls. Results: The discovery cohort, consisting of 10,027,506 individuals (mean age 48.4 years; 49.9% female), revealed heightened risks of gastrointestinal diseases (HR: 1.15; 95% CI: 1.08-1.22), hepatobiliary diseases (1.30; 1.09-1.55), and other digestive abnormalities (1.05; 1.01-1.10) beyond the first 30 days after infection, following exposure-driven propensity score-matching. These results indicate a pronounced association as the severity of COVID-19 increases. The SARS-CoV-2 vaccination was found to lower the risk of gastrointestinal diseases but did not affect hepatobiliary diseases and other digestive disorders. The results derived from validation cohorts were consistent. Over time, the risk profile was most pronounced during the initial 3 months; however, it persisted for >6 months in validation cohorts, but not in the discovery cohort. Conclusions: The incidences of gastrointestinal disease, hepatobiliary disease, and other digestive abnormalities increased in patients with SARS-CoV-2 infection during the post-acute phase.

National prevalence of atopic dermatitis in Korean adolescents from 2009 to 2022.

Previous studies have examined the prevalence of allergic diseases in adolescents 1-2 years after the emergence of the COVID-19 pandemic. However, more data is needed to understand the long-term impact of COVID-19 on allergic diseases. Thus, we aimed to examine the trend of the atopic dermatitis prevalence in Korean adolescents before and during the COVID-19 pandemic across 14 years. Additionally, we analyze the risk factors of atopic dermatitis (AD) based on the results. The Korean Disease Control and Prevention Agency conducted the Korea Youth Risk Behavior Web-based Survey from 2009 to 2022, from which the data for this study were obtained. Prevalence trends were compared across subgroups, and the ß difference (ßdiff) was calculated. We computed odds ratios to examine changes in the disease prevalence before and during the pandemic. This study included a total of 917,461 participants from 2009 to 2022. The prevalence of atopic dermatitis increased from 6.79% (95% CI 6.66-6.91) in 2009-2011 to 6.89% (95% CI 6.72-7.05) in 2018-2019, then decreased slightly to 5.82% (95% CI 5.60-6.04) in 2022. Across the 14 years, middle school student status, low parent's highest education level, low household income, non-alcohol consumption, non-smoker smoking status, no suicidal thoughts, and no suicide attempts were associated with increased risk of atopic dermatitis, while female sex, rural residence, high BMI, low school performance, low household income, and no feelings of sadness and despair was associated with a small increase. This study examined the prevalence of atopic dermatitis across an 18-year, and found that the prevalence increased in the pre-pandemic then decreased during the start of the pandemic and remained constant throughout the pandemic. This trend could be explained mainly by the large scale social and political changes that occurred during the COVID-19 pandemic.

Slow gut transit increases the risk of Alzheimer's disease: An integrated study of the bi-national cohort in South Korea and Japan and Alzheimer's disease model mice.

INTRODUCTION: Although the association between Alzheimer's disease (AD) and constipation is controversial, its causality and underlying mechanisms remain unknown. OBJECTIVES: To investigate the potential association between slow gut transit and AD using epidemiological data and a murine model. METHODS: We conducted a bi-national cohort study in South Korea (discovery cohort, N=3,130,193) and Japan (validation cohort, N=4,379,285) during the pre-observation period to determine the previous diagnostic history (2009-2010) and the follow-up period (2011-2021). To evaluate the causality, we induced slow gut transit using loperamide in 5xFAD transgenic mice. Changes in amyloid-beta (Aß) and other markers were examined using ELISA, qRT-PCR, RNA-seq, and behavioral tests. RESULTS: Constipation was associated with an increased risk of AD in the discovery cohort (hazard ratio, 2.04; 95% confidence interval [CI], 2.01-2.07) and the validation cohort (hazard ratio; 2.82; 95% CI, 2.61-3.05). We found that loperamide induced slower gut transit in 5xFAD mice, increased Aß and microglia levels in the brain, increased transcription of genes related to norepinephrine secretion and immune responses, and decreased the transcription of defense against bacteria in the colonic tissue. CONCLUSION: Impaired gut transit may contribute to AD pathogenesis via the gut-brain axis, thus suggesting a cyclical relationship between intestinal barrier disruption and Aß accumulation in the brain. We propose that gut transit or motility may be a modifiable lifestyle factor in the prevention of AD, and further clinical investigations are warranted.

National trends in depression and suicide attempts and COVID-19 pandemic-related factors, 1998-2021: A nationwide study in South Korea.

BACKGROUND: Despite the significant psychiatric effects of the COVID-19 pandemic, there's limited data on the prevalence and risk factors of depression and suicide attempts among South Korean adults. METHODS: A nationwide cross-sectional study using the Korea National Health and Nutrition Examination Survey (KNHANES) data from 1998 to 2021 was conducted. Changes in prevalence and risk factors for depression and suicide attempts were assessed using weighted odds ratios or weighted beta coefficients. RESULTS: During the observation period (1998-2021), the prevalence of depression increased in the overall population; however, no significant surge was found regarding the COVID-19 pandemic, from 2.78% (95% CI, 2.41-3.15) in 1998-2005-4.96% (4.32-5.61) in 2020 and 5.06% (4.43-5.69) in 2021. However, immediately after the onset of the pandemic, younger ages, male sex, urban residence, higher education, and high economic status became significant vulnerable factors compared to pre-pandemic periods. The prevalence of suicide attempts remained stable, and there was no notable surge specifically related to the COVID-19 pandemic, from 0.23% (95% CI, 0.18-0.28) in 1998-2005-0.45% (0.25-0.66) in 2020 and 0.42% (0.24-0.60) in 2021. Furthermore, no distinct vulnerable factors associated with suicide attempts have been identified. CONCLUSION: Through this nationwide serial cross-sectional survey study, we emphasized the need for understanding the differential impacts of global crises, such as COVID-19, across varied population subgroups, thereby highlighting the importance of specific and targeted mental health support strategies.

National and regional trends in the prevalence of type 2 diabetes and associated risk factors among Korean adults, 2009-2021.

Disproportionate impact of COVID-19 on socioeconomic and behavioral variables may have impacted the prevalence of diabetes. We utilized nationwide long-term serial study from the 2009 to 2021 Korea Community Health Survey (KCHS). We explored national and regional prevalence and trends of diabetes according to the socioeconomic and behavioral factors before and during the pandemic. Also, we interpreted which groups became more vulnerable to the prevalence of diagnosed diabetes during the pandemic. A total of 2,971,349 adults aged (19 to 39, 40 to 59, and ≥ 60 years) were included in the analysis. The prevalence of diagnosed diabetes increased slowly during the pandemic (11.6% [95% CI 11.5-11.7] in 2020 and 12.4% [95% CI 12.3-12.6] in 2021), compared to the pre-pandemic era (7.9% [95% CI 7.8-7.9] in 2009-2011 and 11.3% [95% CI 11.3-11.4] in 2018-2019). Also, women, low-income group, low-educational group, and infrequent walking group showed less prevalence of diagnosed diabetes than the others. The diabetic population increased slowly than expected during the pandemic. The pandemic seems to contribute to an unanticipated increase in under-diagnosis of diabetes among the already minority. This study may suggest reinforcing access to healthcare services among the minority during the pandemic.