Background: Although the coronavirus pandemic significantly affected antibiotic use, studies on the long-term effects of the pandemic on antibiotic use are lacking. We aimed to investigate the changes in antibiotic prescriptions during the pandemic and subsequent endemic period in South Korea.
Methods: For this interrupted time-series study, we used claims data from the National Health Insurance System for January 2018 to December 2023.
Background: This study aimed to investigate the modifying effects of rare genetic variants on the risk of type 2 diabetes mellitus (T2DM) in the context of common genetic and lifestyle factors.
Methods: We conducted a comprehensive analysis of genetic and lifestyle factors associated with T2DM in a cohort of 146,284 Korean individuals. Among them, 4,603 individuals developed T2DM during the follow-up period of up to 17 years.
Background: Polygenic risk scores (PRSs) improve type 2 diabetes (T2D) prediction beyond clinical risk factors but perform poorly in non-European populations, where T2D burden is often higher, undermining their global clinical utility.
Methods: We conducted the largest global effort to date to harmonize T2D genome-wide association study (GWAS) meta-analyses across five ancestries-European (EUR), African/African American (AFR), Admixed American (AMR), South Asian (SAS), and East Asian (EAS)-including 360,000 T2D cases and 1·8 million controls (41% non-EUR). We constructed ancestry-specific and multi-ancestry PRSs in training datasets including 11,000 T2D cases and 32,000 controls, and validated their performance in independent datasets including 39,000 T2D cases and 126,000 controls of diverse ancestries.
Polygenic scores (PGSs) for body mass index (BMI) may guide early prevention and targeted treatment of obesity. Using genetic data from up to 5.1 million people (4.
View Article and Find Full Text PDFObjectives: Systemic lupus erythematosus (SLE) is a complex autoimmune disease strongly associated with the major histocompatibility complex (MHC) region, but precisely pinpointing the risk variants remains challenging. This study aimed to comprehensively profile SLE-driving variants using a newly developed East Asian MHC imputation reference panel, capable of simultaneously imputing diverse MHC variants, including multilevel human leukocyte antigen (HLA) variants and copy number variations (CNVs) of C4 elements, such as C4A, C4B, and human endogenous retrovirus (HERV).
Methods: Using the whole-genome-sequencing (WGS) data from ∼2000 Korean samples, we genotyped and phased MHC variants, including HLA variants and C4-related CNVs, to construct an MHC reference panel.
J Alzheimers Dis
July 2025
BackgroundDementia is a major public health challenge, yet existing prediction models often overlook sleep-related symptoms, despite their known links to cognitive decline.ObjectiveTo develop and validate a four-year Dementia Risk Score (DRS) incorporating self-reported sleep-related symptoms with demographic and clinical factors to predict all-cause dementia, including Alzheimer's disease.MethodsData from 3082 Korean adults aged 60-79 years were analyzed.
View Article and Find Full Text PDFAlzheimers Dement
April 2025
Introduction: Numerous studies on Alzheimer's disease polygenic risk scores (PRSs) overlook sample overlap between International Genomics of Alzheimer's Project (IGAP) and target datasets like Alzheimer's Disease Neuroimaging Initiative (ADNI).
Methods: To address this, we developed overlap-adjusted PRS (OA PRS) and tested it on simulated data to assess biases from different scenarios by varying training, testing, and overlap proportions. OA PRS was used to adjust for sample bias in simulations; then, we applied OA PRS to IGAP and ADNI datasets and validated through visual diagnosis.
Background: Residual symptoms experienced by patients with bipolar disorder (BD) is a risk factor for illness relapse/recurrence, and these symptoms are associated with a lower quality of life. Resilience allows patients to cope with stress effectively and acts as a protective factor against relapse. Therefore, this study aimed to determine the relationship between resilience and residual subjective depressive symptoms in euthymic patients with BD.
View Article and Find Full Text PDFBackground & Aims: The impact of vitamin D deficiency (VDD) on cognition remains controversial. Evidences suggest that variability based on apolipoprotein E (APOE) ε4 status and gender, given APOE ε4's influence on vitamin D metabolism and women's heightened vitamin D sensitivity. We investigated the interplay between APOE ε4, gender, and VDD in cognitive decline among older adults.
View Article and Find Full Text PDFJ Korean Med Sci
September 2024
Background: A decline in masticatory function may indicate brain dysfunction related to dementia, but the relationship between masticatory function and dementia risk remains unclear. This study aimed to investigate whether masticatory function is associated with the risk of cognitive decline and dementia.
Methods: Data were obtained from the nationwide prospective cohort study of randomly sampled community-dwelling Koreans aged ≥ 60 years.
BMC Med Genomics
September 2024
Background: Pathogenic variants of MYH7, which encodes the beta-myosin heavy chain protein, are major causes of dilated and hypertrophic cardiomyopathy.
Methods: In this study, we used whole-genome sequencing data to identify MYH7 variants in 397 patients with various cardiomyopathy subtypes who were participating in the National Project of Bio Big Data pilot study in Korea. We also performed in silico analyses to predict the pathogenicity of the novel variants, comparing them to known pathogenic missense variants.
Front Endocrinol (Lausanne)
July 2024
Conflicting findings have been reported regarding the association between Agent Orange (AO) exposure and type 2 diabetes. This study aimed to examine whether AO exposure is associated with the development of type 2 diabetes and to verify the causal relationship between AO exposure and type 2 diabetes by combining DNA methylation with DNA genotype analyses. An epigenome-wide association study and DNA genotype analyses of the blood of AO-exposed and AO-unexposed individuals with type 2 diabetes and that of healthy controls were performed.
View Article and Find Full Text PDFNat Commun
April 2024
Hyperuricemia is an essential causal risk factor for gout and is associated with cardiometabolic diseases. Given the limited contribution of East Asian ancestry to genome-wide association studies of serum urate, the genetic architecture of serum urate requires exploration. A large-scale cross-ancestry genome-wide association meta-analysis of 1,029,323 individuals and ancestry-specific meta-analysis identifies a total of 351 loci, including 17 previously unreported loci.
View Article and Find Full Text PDFAm J Geriatr Psychiatry
August 2024
Background: The relationship between depression and the risk of multimorbidity progression has rarely been studied in older adults. This study was aimed to determine whether depression is associated with progression in the severity and complexity of multimorbidity, considering the influence of depression's severity and subtype.
Methods: As a part of the Korean Longitudinal Study on Cognitive Aging and Dementia, this population-based cohort study followed a random sample of community-dwelling Koreans aged 60 and older for 8 years at 2-year intervals starting in 2010.
Introduction: Tacrine, an FDA-approved acetylcholinesterase inhibitor, has shown efficacy in treating Alzheimer's disease, but its clinical use is limited by hepatotoxicity. This study investigates the protective effects of red ginseng against tacrine-induced hepatotoxicity, focusing on oxidative stress.
Methods: A network depicting the interaction between compounds and targets was constructed for RG.
Epidemiol Health
May 2025
Objectives: The relationship of depressive symptoms to lower extremity function and balance, especially in older adults without a depression diagnosis, remains unclear. Therefore, our study analyzed this relationship using a large sample of Korean older adults.
Methods: We used data from the Korean National Health Insurance Service's Health Screening Program database.
Clin Psychopharmacol Neurosci
November 2023
Objective: : To investigate the relationship between reduced glutathione (GSH), a key molecule of the antioxidant defense system in the blood, and glutathione reductase (GR), which reduces oxidized glutathione (glutathione disulfide [GSSG]) to GSH and maintains the redox balance, with the prevalence of Alzheimer's dementia and cognitive decline.
Methods: : In all, 20 participants with Alzheimer's dementia who completed the third follow-up clinical evaluation over 6 years were selected, and 20 participants with normal cognition were selected after age and sex matching. The GSH and GR concentrations were the independent variables.
J Korean Acad Child Adolesc Psychiatry
October 2023
Objectives: Following the coronavirus disease 2019 (COVID-19) pandemic, adolescents have experienced decreased physical activity and a decline in mental health. This study analyzed the association between changes in depressed mood after the COVID-19 pandemic and physical activity among adolescents.
Methods: The analysis was based on the results of the 17th Youth Health Behavior Online Survey conducted in 2021, which included 54848 middle and high school students in South Korea.
Background: Integrating a joint approach to chronic disease management within the context of a couple has immense potential as a valuable strategy for both prevention and treatment. Although spousal concordance has been reported in specific chronic illnesses, the impact they cumulatively exert on a spouse in a longitudinal setting has not been investigated. We aimed to determine whether one's cumulative illness burden has a longitudinal impact on that of their spouse.
View Article and Find Full Text PDFBackground: There are growing concerns about the impact of the COVID-19 pandemic on the mental health of older adults. We examined the effect of the pandemic on the risk of depression in older adults.
Methods: We analyzed data from the prospective cohort study of Korean older adults, which has been followed every 2 years.
Psychiatry Clin Neurosci
August 2023