Although WHO declared the end of the public health emergency for coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV-2), XBB lineages continue to evolve and emerge globally. In particular, XBB.1.5 and XBB.1.16 are raising concerns because of their high immune evasion, leading to apprehensions regarding vaccine efficacy reduction and potential reinfection. We aimed to investigate the COVID-19 outbreak in Korea and predict the likelihood of reinfection by testing neutralizing activity against live viruses from the S clade and 19 Omicron sublineages.We found a significant risk of infection with the currently prevalent XBB lineage for individuals who were either vaccinated early or infected during the initial Omicron outbreak. Vaccinated individuals were better equipped than unvaccinated individuals to produce neutralizing antibodies for other SARS-CoV-2 variants upon infection. Therefore, unvaccinated individuals do not easily develop neutralizing activity against other variants and face the highest risk of reinfection by the XBB lineage. Our study provides important information to facilitate the development of strategies for monitoring populations that would be the most susceptible to new COVID-19 outbreaks.

Background: Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data. Methods: The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180–210 days (referent), within 30–90 days of delayed dosing (DD90), within 90–180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures. Results: A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures. Conclusion Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Background: Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data. Methods: The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180–210 days (referent), within 30–90 days of delayed dosing (DD90), within 90–180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures. Results: A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures. Conclusion Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Background: Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data. Methods: The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180–210 days (referent), within 30–90 days of delayed dosing (DD90), within 90–180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures. Results: A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures. Conclusion Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Background: Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data. Methods: The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180–210 days (referent), within 30–90 days of delayed dosing (DD90), within 90–180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures. Results: A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures. Conclusion Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Background: The coronavirus disease 2019 (COVID-19) pandemic led to a decrease in the seasonal incidence of many respiratory viruses worldwide due to the impact of nonpharmaceutical interventions (NPIs). However, as NPI measures were relaxed, respiratory viral infections re-emerged. We aimed to characterize the epidemiology of respiratory viruses in Korean children during post-COVID-19 pandemic years compared to that before the pandemic. Methods: A nationwide prospective ongoing surveillance study has been conducted for detection of respiratory viruses between January 2017 and June 2023. We included data on adenovirus (AdV), human bocavirus (HBoV), human coronavirus (HCoV), human metapneumovirus (HMPV), human rhinovirus (HRV), influenza virus (IFV), parainfluenza virus (PIV), and respiratory syncytial virus (RSV), which were detected in children and adolescents younger than 20 years. We analyzed the weekly detection frequency of individual viruses and the age distribution of the affected children. The study period was divided into prepandemic (2017–2019) and postpandemic (2021–2023) periods. Results: A total of 19,589 and 14,068 samples were collected in the pre- and postpandemic periods, respectively. The overall detection rate of any virus throughout the study period was 63.1%, with the lowest occurring in the 2nd half of 2020 (50.6%) and the highest occurring in the 2nd half of 2021 (72.3%). Enveloped viruses (HCoV, HMPV, IFV, PIV, and RSV) almost disappeared, but nonenveloped viruses (AdV, HBoV, and HRV) were detected even during the peak of the COVID-19 pandemic. The codetection rate increased from 15.0% prepandemic to 19.1% postpandemic (P < 0.001). During the postpandemic period, a large out-of-season PIV and HMPV epidemic occurred, but the usual seasonality began to be restored in 2023.The mean age of children with each virus detected in 2023 was significantly greater than that in prepandemic years (P = 0.003 and 0.007 for AdV and HCoV, respectively; P < 0.001 for others). The mean age of children with IFV increased in 2022 (11.1 ± 5.2 years) from prepandemic years (7.9 ± 4.6 years) but decreased to 8.7 ± 4.1 years in 2023. Conclusion With the relaxation of NPI measures, several seasonal respiratory viruses cocirculated with unusual seasonal epidemic patterns and were associated with increasing age of infected children.

Background: Coronary artery calcium score (CACS) has become an important tool for evaluating cardiovascular disease (CVD). This study evaluated the significance of CACS for future CVD through more than 10 years of follow-up in asymptomatic Korean populations with type 2 diabetes mellitus (T2DM) known to have a relatively low CACS burden. Methods: We enrolled 981 asymptomatic T2DM patients without CVD at baseline who underwent CACS evaluation using multidetector computed tomography between January 2008 and December 2014. They were grouped into five predefined CACS categories based on Agatston scores and followed up by August 2020. The primary endpoint was incident CVD events, including coronary, cerebrovascular, and peripheral arterial disease. Results: The relative risk of CVD was significantly higher in patients with CACS ≥10, and the significance persisted after adjustment for known confounders. A higher CACS category indicated a higher incidence of future CVD: hazard ratio (95% confidence interval) 4.09 (1.79 to 9.36), 12.00 (5.61 to 25.69), and 38.79 (16.43 to 91.59) for 10≤ CACS <100, 100≤ CACS <400, and CACS ≥400, respectively. During the 12-year follow-up period, the difference in event-free survival more than doubled as the category increased. Patients with CACS below 10 had very low CVD incidence throughout the follow-up. The receiver operating characteristic analysis showed better area under curve when the CACS cutoff was 10 than 100. Conclusion CACS can be a sensitive marker of CVD risk. Specifically, CACS above 10 is an indicator of CVD high-risk requiring more intensive medical treatment in Koreans with T2DM.

Humanity is in the midst of the coronavirus disease 2019 (COVID-19) pandemic, and vaccines—including mRNA vaccines—have been developed at an unprecedented speed. It is necessary to develop guidelines for vaccination for people undergoing treatment with assisted reproductive technology (ART) and for pregnancy-related situations based on the extant laboratory and clinical data. COVID-19 vaccines do not appear to adversely affect gametes, embryos, or implantation; therefore, active vaccination is recommended for women or men who are preparing for ART. The use of intravenous immunoglobulin G (IVIG) for the treatment of immune-related infertility is unlikely to impact the effectiveness of the vaccines, so COVID-19 vaccines can be administered around ART cycles in which IVIG is scheduled. Pregnant women have been proven to be at risk of severe maternal and neonatal complications from COVID-19. It does not appear that COVID-19 vaccines harm pregnant women or fetuses; instead, they have been observed to deliver antibodies against severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) to the fetus. Accordingly, it is recommended that pregnant women receive COVID-19 vaccination. There is no rationale for adverse effects, or clinical cases of adverse reactions, in mothers or neonates after COVID-19 vaccination in lactating women. Instead, antibodies to SARS-CoV-2 can be delivered through breast milk. Therefore, breastfeeding mothers should consider vaccination. In summary, active administration of COVID-19 vaccines will help ensure the safe implementation of ART, pregnancy, and breastfeeding.

Background: It is well known that high serum ferritin, a marker of iron storage, predicts incident type 2 diabetes. Limited information is available on the association between transferrin, another marker of iron metabolism, and type 2 diabetes. Thus, we investigated the association between transferrin and incident type 2 diabetes. Methods: Total 31,717 participants (mean age, 40.4±7.2 years) in a health screening program in 2005 were assessed via cross-sectional analysis. We included 30,699 subjects who underwent medical check-up in 2005 and 2009 and did not have type 2 diabetes at baseline in this retrospective longitudinal analysis. Results: The serum transferrin level was higher in the type 2 diabetes group than in the non-type 2 diabetes group (58.32±7.74 μmol/L vs. 56.17±7.96 μmol/L, P<0.001). Transferrin correlated with fasting serum glucose and glycosylated hemoglobin in the correlational analysis (r=0.062, P<0.001 and r=0.077, P<0.001, respectively) after full adjustment for covariates. Transferrin was more closely related to homeostasis model assessment of insulin resistance than to homeostasis model assessment of β cell function (r=0.042, P<0.001 and r=–0.019, P=0.004, respectively) after full adjustment. Transferrin predicted incident type 2 diabetes in non-type 2 diabetic subjects in a multivariate linear regression analysis; the odds ratio (95% confidence interval [CI]) of the 3rd tertile compared to that in the 1st tertile of transferrin for incident diabetes was 1.319 (95% CI, 1.082 to 1.607) after full adjustment (P=0.006). Conclusion Transferrin is positively associated with incident type 2 diabetes in Koreans.

The guidelines for chronic obstructive pulmonary disease (COPD) treatment are important for the management of the disease. However, studies regarding the treatment adherence to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines have been scarce in Korea. Therefore, to examine the adherence to the GOLD guidelines, we examined the patterns of prescribed medication in COPD patients from 2011 to 2018. Patients were classified as having been appropriately and inappropriately treated (overtreatment or undertreatment) for the GOLD group. Appropriate medical therapy was defined as using the first choice or alternative choice drug recommended in the GOLD guidelines. Inappropriate therapy was classified as overtreatment or undertreatment in accordance with the categorization in the GOLD guidelines. According to treatment of 2011 GOLD guidelines, there was inappropriate treatment in 52.3% in group A, 47.3% in group B, 56.3% in group C, and 17.8% in group D. According to treatment of 2017 GOLD guidelines, there was inappropriate treatment in 66.7% in group A, 45.3% in group B, 14.3% in group C, and 24.0% in group D. The common type of inappropriate COPD treatment is overtreatment, with inhaled corticosteroid (ICS) containing regimens. In conclusions, adherence to the GOLD guideline by the pulmonologist in clinical practice is still low in Korea. Therefore, we need better strategies to both optimize the use of the guidelines and adhere to the guidelines as well.
Humans ; Korea* ; Lung Diseases ; Medical Overuse ; Pulmonary Disease, Chronic Obstructive*