Journal of Korean Medical Science最新文献

Background: With a rapid decrease in tuberculosis (TB) incidence, the significance of latent tuberculosis infection (LTBI) has been underscored in South Korea. Although South Korea does not have a high proportion of immigrants compared to other countries, there is a growing argument that it should actively embrace immigrants as a solution to address issues of low birth rates and population aging. This study aimed to assess TB incidence among immigrants who participated a pilot LTBI screening program in South Korea.

Methods: Records of immigrants participated in a pilot LTBI screening program in South Korea between 2018 and 2019 were linked with Korean National TB Surveillance System to determine TB development. Participants underwent interferon-gamma release assay (IGRA) and chest X-rays. Standardized incidence ratios (SIRs) stratified by age, country of origin's TB burden was calculated with a reference group of general South Korean population.

Results: Of a total of 9,517 participants, 14 TB cases were identified. Participants with positive IGRA results who did not initiate LTBI treatment showed TB incidence of 312.5 per 100,000 person-years, whereas those with negative results showed TB incidence of 34.4 per 100,000 person-years, resulting in an incidence rate ratio of 9.08 (95% confidence interval [CI], 2.50-32.99). SIR of TB among total participants including those with negative IGRA results was 2.60 (95% CI, 1.54-4.38; P < 0.001), whereas SIR among those with positive IGRA results was 5.86 (95% CI, 3.15-10.89; P < 0.001). In the calculation of SIR among participants with positive IGRA results, those aged under 35 from high TB-burden countries or intermediate TB-burden countries showed a high SIR (18.08; 95% CI, 2.55-128.37; P = 0.004), and 11.30 (95% CI, 2.82-45.16; P < 0.001), respectively). Contrary to previous reports that suggest the majority of elderly population with a positive IGRA result were due to remote infection and had a lower TB risk compared to younger ages, SIR among those aged 65 or over from intermediate TB-burden countries was 6.15 (95% CI, 0.87-43.69; P = 0.069), which was comparable to that in younger participants aged between 35 and 49 (SIR, 4.87; 95% CI, 1.22-19.49; P = 0.025) or those aged between 50 and 64 (SIR, 4.62; 95% CI, 1.73-12.31; P = 0.002).

Conclusion: Young immigrants with positive IGRA results from countries with high or intermediate TB burden showed a relatively high TB risk compared to a general South Korea population. In addition, unexpected high TB risk was observed among elderly immigrants with positive IGRA results. In establishing future policies for LTBI in immigrants in South Korea, screenings should primarily focus on younger age group (who aged under 35). Additionally, further research is needed on the high TB risk observed in elderly immigrants.

Background: Respiratory syncytial virus (RSV), a highly transmissible virus, is the leading cause of lower respiratory tract infections. We examined molecular changes in the RSV genome before and after the coronavirus disease 2019 (COVID-19) pandemic in Korea, and investigated whether drug-resistant mutations were present.

Methods: In this prospective, single-center study, RSV-positive respiratory samples were collected between September 2019 and December 2022. Long-read whole-genome sequencing (WGS) was performed, and the presence of known drug-resistant substitutions for palivizumab, nirsevimab, and suptavumab was investigated.

Results: Overall, 288 respiratory samples were collected from 276 children. WGS data were available for 133 samples (71 and 62 samples from the pre- and post-pandemic periods, respectively). All RSV-A strains (n = 56) belonged to the GA2.3.5 (ON1) genotype, whereas all RSV-B strains (n = 77) belonged to the GB5.0.5a (BA) genotype. No significant differences in genotypes were observed between the pre- and post-pandemic periods. In addition, no notable mutations related to nirsevimab or palivizumab resistance were detected in the F gene. However, the L172Q and S173L substitutions, which are known to confer resistance to suptavumab, were present in all RSV-B samples.

Conclusion: Despite the unprecedented interruption of RSV seasonality, there were no significant molecular changes in circulating RSV strains in Korea related to nirsevimab or palivizumab resistance before and after the COVID-19 pandemic. However, RSV-specific drug-resistance substitutions for suptavumab were identified.

Background: Relatives share more genomic regions than unrelated individuals, with closer relatives sharing more regions. This concept, paired with the increased availability of high-throughput single nucleotide polymorphism (SNP) genotyping technologies, has made it feasible to measure the shared chromosomal regions between individuals to assess their level of relation to each other. However, such techniques have remained in the conceptual rather than practical stages in terms of applying measures or indices. Recently, we developed an index called "genetic distance-based index of chromosomal sharing (GD-ICS)" utilizing large-scale SNP data from Korean family samples and demonstrated its potential for practical applications in kinship determination. In the current study, we present validation results from various real cases demonstrating the utility of this method in resolving complex familial relationships where information obtained from traditional short tandem repeats (STRs) or lineage markers is inconclusive.

Methods: We obtained large-scale SNP data through microarray analysis from Korean individuals involving 13 kinship cases and calculated GD-ICS values using the method described in our previous study. Based on the GD-ICS reference constructed for Korean families, each disputed kinship was evaluated and validated using a combination of traditional STRs and lineage markers.

Results: The cases comprised those A) that were found to be inconclusive using the traditional approach, B) for which it was difficult to apply traditional testing methods, and C) that were more conclusively resolved using the GD-ICS method. This method has overcome the limitations faced by traditional STRs in kinship testing, particularly in a paternity case with STR mutational events and in confirming distant kinship where the individual of interest is unavailable for testing. It has also been demonstrated to be effective in identifying various relationships without specific presumptions and in confirming a lack of genetic relatedness between individuals.

Conclusion: This method has been proven effective in identifying familial relationships across diverse complex and practical scenarios. It is not only useful when traditional testing methods fail to provide conclusive results, but it also enhances the resolution of challenging kinship cases, which suggests its applicability in various types of practical casework.

Background: As one of the most challenging fractures to orthopedic surgeons, acetabular fractures show a wide range of incidence among countries and regions with even more variance in the treatment modalities. In this study, we aimed to investigate the epidemiology of acetabular fractures, and to compare the rate of subsequent total hip arthroplasty (THA) between nonoperative and operative treatments in South Korea using a medical claims database.

Methods: This was a retrospective study using the Korean Health Insurance Review and Assessment database. Patients admitted for acetabular fractures from January 2007 to December 2018 were identified using International Classification of Diseases-10 codes. Kaplan-Meier survival analysis was used to compare the cumulative incidence of THA between two groups. We also evaluated the survivorship of operative group according to the type of institutions.

Results: The incidence rate of acetabular fractures increased by 28% between 2007 and 2018. Acetabular fractures were more common in men (62%) than women (38%), and most common in the patients older than 80 years. The number of acetabular fractures was estimated to increase 1.7-fold in 2030 compared to 2018. Operative treatment accounted for 16% of cases, and nonoperative treatment for 84%. The incidence of subsequent THA was higher in the operative treatment group than in the nonoperative group (P < 0.001). The higher rate in the operative treatment group is probably related with the severity of the fracture type. The rate of subsequent THA was higher in patients who initially treated in general hospitals compared with those who were initially treated in tertiary hospitals.

Conclusion: The incidence of acetabular fractures is increasing in South Korea, in line with global trends. Most acetabular fractures are treated conservatively, and those who receive surgery are more likely to require a subsequent THA. Patients who were operated in general hospitals had highest possibility of subsequent THA after acetabular fractures.

Background: The prevalence of diabetes is increasing globally, highlighting the importance of preventive healthcare. This study aimed to identify the diabetic retinopathy (DR) screening rates and risk factors linked to DR screening nonadherence in the Korean population through a nationally representative sample survey.

Methods: Among the Korea National Health and Nutrition Examination Survey database from 2016 to 2021, participants aged ≥ 40 years with diabetes were included. The weighted estimate for nonadherence to DR screening within a year was calculated. Risk factor analyses were conducted using univariate and multivariate logistic regression.

Results: Among the 3,717 participants, 1,109 (29.5%) underwent DR screening within the past year, and this national estimate exhibited no statistically significant difference from 2016 to 2021 (P = 0.809). Nonadherence to annual DR screening was associated with residing in rural areas, age ≥ 80 years, low educational level, self-reported good health, absence of ocular disease, current smoking, lack of exercise and dietary diabetes treatment, and no activity limitation (all P < 0.05).

Conclusion: The recent DR screening rate in Korea was relatively low. Factors associated with apathy and complacency towards personal health were associated with the nonadherence to DR screening. Educational interventions have the potential to enhance the annual screening rate for diabetic patients.

Background: Sarcopenia, characterized by a progressive decline in muscle mass, strength, and function, is primarily attributable to aging. DNA methylation, influenced by both genetic predispositions and environmental exposures, plays a significant role in sarcopenia occurrence. This study employed machine learning (ML) methods to identify differentially methylated probes (DMPs) capable of diagnosing sarcopenia in middle-aged individuals. We also investigated the relationship between muscle strength, muscle mass, age, and sarcopenia risk as reflected in methylation profiles.

Methods: Data from 509 male participants in the urban cohort of the Korean Genome Epidemiology Study_Health Examinee study were categorized into quartile groups based on the sarcopenia criteria for appendicular skeletal muscle index (ASMI) and handgrip strength (HG). To identify diagnostic biomarkers for sarcopenia, we used recursive feature elimination with cross validation (RFECV), to pinpoint DMPs significantly associated with sarcopenia. An ensemble model, leveraging majority voting, was utilized for evaluation. Furthermore, a methylation risk score (MRS) was calculated, and its correlation with muscle strength, function, and age was assessed using likelihood ratio analysis and multinomial logistic regression.

Results: Participants were classified into two groups based on quartile thresholds: sarcopenia (n = 37) with ASMI and HG in the lowest quartile, and normal ranges (n = 48) in the highest. In total, 238 DMPs were identified and eight probes were selected using RFECV. These DMPs were used to build an ensemble model with robust diagnostic capabilities for sarcopenia, as evidenced by an area under the receiver operating characteristic curve of 0.94. Based on eight probes, the MRS was calculated and then validated by analyzing age, HG, and ASMI among the control group (n = 424). Age was positively correlated with high MRS (coefficient, 1.2494; odds ratio [OR], 3.4882), whereas ASMI and HG were negatively correlated with high MRS (ASMI coefficient, -0.4275; OR, 0.6521; HG coefficient, -0.3116; OR, 0.7323).

Conclusion: Overall, this study identified key epigenetic markers of sarcopenia in Korean males and developed a ML model with high diagnostic accuracy for sarcopenia. The MRS also revealed significant correlations between these markers and age, HG, and ASMI. These findings suggest that both diagnostic models and the MRS can play an important role in managing sarcopenia in middle-aged populations.

During the coronavirus disease 2019 (COVID-19) pandemic, conclusively evaluating possible associations between COVID-19 vaccines and potential adverse events was of critical importance. The National Academy of Medicine of Korea established the COVID-19 Vaccine Safety Research Center (CoVaSC) with support from the Korea Disease Control and Prevention Agency to investigate the scientific relationship between COVID-19 vaccines and suspected adverse events. Although determining whether the COVID-19 vaccine was responsible for any suspected adverse event necessitated a systematic approach, traditional causal inference theories, such as Hill's criteria, encountered certain limitations and criticisms. To facilitate a systematic and evidence-based evaluation, the United States Institute of Medicine, at the request of the Centers for Disease Control and Prevention, offered a detailed causality assessment framework in 2012, which was updated in the recent report by the National Academies of Sciences, Engineering, and Medicine (NASEM) in 2024. This framework, based on a weight-of-evidence approach, allows the independent evaluation of both epidemiological and mechanistic evidence, culminating in a comprehensive conclusion about causality. Epidemiological evidence derived from population studies is categorized into four levels-high, moderate, limited, or insufficient-while mechanistic evidence, primarily from biological and clinical studies in animals and individuals, is classified as strong, intermediate, weak, or lacking. The committee then synthesizes these two types of evidence to draw a conclusion about the causal relationship, which can be described as "convincingly supports" ("evidence established" in the 2024 NASEM report), "favors acceptance," "favors rejection," or "inadequate to accept or reject." The CoVaSC has established an independent committee to conduct causality assessments using the weight-of-evidence framework, specifically for evaluating the causality of adverse events associated with COVID-19 vaccines. The aim of this study is to provide an overview of the weight-of-evidence framework and to detail the considerations involved in its practical application in the CoVaSC.

Background: The relationship between aspirin usage and the risk of colorectal cancer (CRC) among individuals with both hypertension (HTN) and diabetes mellitus (DM) remains unclear. This study aims to explore the impact of aspirin use on the site-specific CRC risk in patients with metabolic comorbidity.

Methods: A case-control study was conducted among 1,331 CRC patients and 2,771 controls recruited from the Nation Cancer Center in Korea. Multinomial logistic regression analyses were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the association between aspirin use, metabolic disease status, and site-specific CRC risk.

Results: Among the 4,102 participants, 1,191 individuals had neither HTN nor DM, 2,044 were diagnosed with HTN, 203 with DM, and 664 presented with HTN and DM comorbidity. An increasing number of HTN and DM was associated with an increased risk of overall CRC (HTN or DM: OR, 1.70; 95% CI, 1.39-2.07; HTN and DM: OR, 8.43; 95% CI, 6.37-11.16), while aspirin use was associated with a decreased risk of overall CRC (OR, 0.31; 95% CI, 0.21-0.46). These results remained consistent across anatomical sites. Among individuals with HTN and DM comorbidity, aspirin use notably associated with lower risk of overall CRC (OR, 0.39; 95% CI, 0.21-0.72), proximal colon (OR, 0.32; 95% CI, 0.13-0.71) and rectal cancer (OR, 0.27; 95% CI, 0.08-0.97), but not distal colon cancer (OR, 0.58; 95% CI, 0.27-1.24).

Conclusion: This study showed that aspirin use is negatively associated with overall and site-specific CRC, even among individuals with HTN and DM comorbidity.