Background/Aims: Early studies on direct oral anticoagulants (DOACs) reported a higher risk of gastrointestinal bleeding (GIB) compared with warfarin; however, recent studies have reported a reduced risk. Therefore, this study was designed to evaluate the risk of GIB in users of DOAC and warfarin. Methods: Using a common data model, we investigated the comparative risk of GIB in subjects from eight hospitals who were newly prescribed DOACs or warfarin. We excluded subjects who had a prior history of GIB or had been prescribed both medications. After propensity score matching, we analyzed 3,347 matched pairs of new DOAC and new warfarin users. Results: The risk of GIB in new DOAC users was comparable to that in new warfarin users (hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.65 to 1.40; p=0.808). New DOAC users had a similar risk of GIB to new warfarin users among older patients >65 years (HR, 1.00; 95% CI, 0.69 to 1.52; p=0.997) and in older patients >75 years (HR, 1.21; 95% CI, 0.68 to 2.10; p=0.509). In addition, the risk of GIB was not significantly different between two groups according to sex. We also found that the risk of GIB in DOAC users was 26% lower in edoxaban or apixaban subgroups compared to rivaroxaban or dabigatran subgroups (HR, 0.74; 95% CI, 0.69 to 1.00; p=0.049). Conclusions In real-world practice, the risk of GIB in new DOAC users is comparable to that in new warfarin users. In DOAC users, the risk of GIB was lower in edoxaban or apixaban subgroups than rivaroxaban or dabigatran subgroups.

This manuscript represents the official position of the Korean Society of Echocardiography on valvular heart diseases.This position paper focuses on the clinical management of valvular heart diseases with reference to the guidelines recently published by the American College of Cardiology/American Heart Association and the European Society of Cardiology. The committee tried to reflect the recently published results on the topic of valvular heart diseases and Korean data by a systematic literature search based on validity and relevance. In part I of this article, we will review and discuss the current position of aortic valve disease in Korea.

This manuscript represents the official position of the Korean Society of Echocardiography on valvular heart diseases.This position paper focuses on the diagnosis and management of valvular heart diseases with referring to the guide‑ lines recently published by the American College of Cardiology/American Heart Association and the European Society of Cardiology. The committee sought to reflect national data on the topic of valvular heart diseases published to date through a systematic literature search based on validity and relevance. In the part II of this article, we intend to pre‑ sent recommendations for diagnosis and treatment of mitral valve disease and tricuspid valve disease.

Given that tooth loss is a degenerative change, the number of residual teeth may be used to specify a particular age range as a marker for age estimation. This study examined changes in the number of teeth with age using a nationwide oral survey database and derived the age distribution of the Korean population according to the number of teeth. Data on the number of teeth and age were extracted from the oral examination data of the Korean National Health and Nutrition Examination Survey (KNHANES) from 2016 to 2018. Statistical analyses of a complex sample survey were performed using weighted values. The distribution range of the number of teeth by age was broad. The proportion of young people decreased progressively as the number of remaining teeth decreased. In contrast, the proportion of those from the older age group decreased slightly as the number of teeth increased. The number of teeth was subdivided into groups of four, age was categorized into 5-year intervals, and the distribution of age groups by the number of teeth was analyzed. We attempted to determine the age group threshold at approximately 95th percentile for age. In summary, we found that if there were ≤4, 5-12, and 13-20 residual teeth, the estimated age was ≥60, ≥55, and ≥50 years, respectively, with an approximately 95% probability. When many teeth are lost and it is difficult to apply conventional dental age estimation methods, our method may assist in narrowing the age range, although it is not an accurate age determination method.

Background/Aims: Nutritional status influences quality of life among patients with inflammatory bowel disease (IBD), although there is no clear method to evaluate nutritional status in this setting. Therefore, this study examined whether bioelectrical impedance analysis (BIA) could be used to evaluate the nutritional status of patients with IBD. Methods: We retrospectively analyzed data from 139 Korean patients with IBD who were treated between November 2018 and November 2019. Patients were categorized as having active or inactive IBD based on the Harvey-Bradshaw index (a score of ≥5 indicates active Crohn’s disease) and the partial Mayo scoring index (a score of ≥2 indicates active ulcerative colitis). BIA results and serum nutritional markers were analyzed according to disease activity. Results: The mean patient age was 45.11±17.71 years. The study included 47 patients with ulcerative colitis and 92 patients with Crohn’s disease. Relative to the group with active disease (n=72), the group with inactive disease (n=67) had significantly higher values for hemoglobin (P<0.001), total protein (P<0.001), and albumin (P<0.001). Furthermore, the group with inactive disease had higher BIA values for body moisture (P=0.047), muscle mass (P=0.046), skeletal muscle mass (P=0.042), body mass index (P=0.027), and mineral content (P=0.034). Moreover, the serum nutritional markers were positively correlated with the BIA results. Conclusions Nutritional markers evaluated using BIA were correlated with serum nutritional markers and inversely correlated with disease activity. Therefore, we suggest that BIA may be a useful tool that can help existing nutritional tests monitor the nutritional status of IBD patients.

Background: and Purpose: Medication adherence is essential for effective medical treatment.However, it is challenging for cognitively impaired patients. We investigated whether an automated telephone reminder service improves medication adherence and reduces the decline of cognitive function in isolated patients with cognitive impairment. Methods: This was a single-center, randomized clinical trial. We enrolled mild cognitive impairment (MCI) or Alzheimer’s disease (AD) patients who lived alone or with a cognitively impaired spouse. We provided an automated telephone reminder service for taking medication to the intervention group for 6 months. The control group was provided with general guidelines for taking the medication every month. The participants underwent neuropsychological assessment at the beginning and end of the study. Statistical significance was tested using nonparametric Wilcoxon rank sum and Wilcoxon matched-pairs signed-rank tests. Results: Thirty participants were allocated randomly to groups, and data for 29 participants were analyzed. The mean age was 79.6 (standard deviation, 6.0) years and 79.3% of the participants were female. There was no significant difference in medication adherence between the 2 groups. However, a subgroup analysis among participants with more than 70% response rates showed better medication adherence compared to the control group (intervention: 94.6%; control: 90.2%, p=0.0478). There was no significant difference in the change in cognitive function between the 2 groups. Conclusions If a patient’s compliance is good, telephone reminders might be effective in improving medication adherence. It is necessary to develop reminder tools that can improve compliance for cognitively impaired patients.

The 26S proteasome irreversibly hydrolyzes polyubiquitylated substrates to maintain protein homeostasis; it also regulates immune responses by generating antigenic peptides. An alternative form of the 26S proteasome is the immunoproteasome, which contains substituted catalytic subunits (β1i/PSMB9, β2i/PSMB10, and β5i/PSMB8) instead of constitutively expressed counterparts (β1/PSMB6, β2/PSMB7, and β5/PSMB5). The immunoproteasome expands the peptide repertoire presented on MHC class I molecules. However, how its activity changes in this context is largely elusive, possibly due to the lack of a standardized methodology to evaluate its specific activity. Here, we describe an assay protocol that measures the immunoproteasome activity of whole-cell lysates using commercially available fluorogenic peptide substrates. Our results showed that the most accurate assessment of immunoproteasome activity could be achieved by combining β5itargeting substrate Ac-ANW-AMC and immunoproteasome inhibitor ONX-0914. This simple and reliable protocol may contribute to future studies of immunoproteasomes and their pathophysiological roles during viral infection, inflammation, and tumorigenesis.