Purpose: Isometric handgrip exercise (IHE) has a favorable cardiovascular effect and improves hemodynamic responses. Whether IHE attenuates stress-related hemodynamic reactivity assessed during a sympathetic challenge remains unexplored. We tested the hypothesis that an acute bout of IHE would improve carotid arterial function and attenuate cardiovascular vasoreactivity response to sympathetic stress in healthy adults. Methods: In a randomized cross-over design, sixteen healthy adults (aged 21.8±3.1 years) were enrolled. Participants completed two testing sessions, separated by 1 week. Trials were either a control trial or performed IHE for two sets of 2 minutes at 30% of maximal voluntary contraction for each hand. The participant’s hand was immersed in an ice water bath (4 ℃ ) up to the wrist for 2 minutes. Carotid artery diameter, β-stiffness index, and compliance using ultrasound machine and brachial blood pressure (BP), heart rate (HR) were measured as indices of vasoreactivity at baseline, during, and recovery from cold pressor testing (CPT). Results: The BP, HR, carotid artery diameter, and β-stiffness index increased similarly during CPT in both trials (p＜ 0.001), without any interaction effect. Compared with the IHE trial, arterial compliance decreased in the control groups at 120 seconds during recovery with a significant interaction effect (p=0.02). Conclusion These findings suggest that an acute IHE did not attenuate BP, HR, carotid artery diameter and β-stiffness index vasoreactivity, but improved carotid artery compliance to sympathetic activation in healthy young adults.

We investigated whether endurance exercise training (EXT) ameliorates circadian rhythm (CR)-induced risk factors by improving skeletal muscle (SKM) mitochondrial biogenesis, reducing oxidative stress, and modulating apoptotic protein expression. We distinguished between regular and shift workers using the National Health and Nutrition Examination Survey (NHANES) and investigated the health problems caused by shift work (CR disturbance) and the potential therapeutic effects of exercise. In our animal study, 36 rats underwent 12 weeks of CR disturbance, divided into regular and irregular CR groups. These groups were further split into EXT (n = 12) and sedentary (n = 12) for an additional 8 weeks. We analyzed SKM tissue to understand the molecular changes induced by CR and EXT. NHANES data were analyzed using SAS 9.4 and Prism 8 software, while experimental animal data were analyzed using Prism 8 software. The statistical procedures used in each experiment are indicated in the figure legends. Our studies showed that CR disturbance increases dyslipidemia, alters circadian clock proteins (BMAL1, PER2), raises apoptotic protein levels, and reduces mitochondrial biogenesis in SKM. EXT improved LDL-C and HDLC levels without affecting muscle BMAL1 expression. It also enhanced mitochondrial biogenesis (AMPK, PGC-1α, Tfam, NADH-UO, COX-I), antioxidant levels (Catalase, SOD1, SOD2), and apoptotic protein (p53, Bax/Bcl2) expression or activity in SKM. We demonstrated that shift work-induced CR disturbance leads to dyslipidemia, diminished mitochondrial biogenesis, and reduced antioxidant capacity in SKM. However, EXT can counteract dyslipidemia under CR disturbance, potentially lowering the risk of cardiovascular disorders.

Purpose: This study aimed to determine whether micro-flow imaging (MFI) offers diagnostic performance comparable to that of contrast-enhanced ultrasonography (CEUS) in detecting segmental congestion among patients undergoing living donor liver transplantation (LDLT). Methods: Data from 63 patients who underwent LDLT between May and December 2022 were retrospectively analyzed. MFI and CEUS data collected on the first postoperative day were quantified. Segmental congestion was assessed based on imaging findings and laboratory data, including liver enzymes and total bilirubin levels. The reference standard was a postoperative contrast-enhanced computed tomography scan performed within 2 weeks of surgery. Additionally, a subgroup analysis examined patients who underwent reconstruction of the middle hepatic vein territory. Results: The sensitivity and specificity of MFI were 73.9% and 67.5%, respectively. In comparison, CEUS demonstrated a sensitivity of 78.3% and a specificity of 75.0%. These findings suggest comparable diagnostic performance, with no significant differences in sensitivity (P=0.655) or specificity (P=0.257) between the two modalities. Additionally, early postoperative laboratory values did not show significant differences between patients with and without congestion. The subgroup analysis also indicated similar diagnostic performance between MFI and CEUS. Conclusion MFI without contrast enhancement yielded results comparable to those of CEUS in detecting segmental congestion after LDLT. Therefore, MFI may be considered a viable alternative to CEUS.

Objectives: This study aimed to determine the time-series changes in provincial diabetes management indices using by results of the 2008-2022 Korea Community Health Survey. Methods: We collected diabetes diagnosis experience rate, treatment rate for people diagnosed with diabetes, annual screening rate for diabetic eye disease complications, and annual screening rate for diabetic kidney disease complications with age-standardized rates from the Regional Health Statistics. The unit of analysis was the nation and 17 provinces and the time-series trend analysis was performed by joinpoint regression using the Joinpoint Regression Program, and the annual percent change (APC) and average APC (AAPC) were estimated, and statistical significance was tested using 95% confidence interval (CI). Results: From 2008-2022, the national AAPC (95% CI) for diabetes diagnosis experience rate steadily increased to 2.77 (2.25-3.27), increasing in all regions, excluding Sejong. The national AAPC for treatment rate for people diagnosed with diabetes was 0.75 (0.47-1.04), with a slight but steady trend toward improvement, excluding Daejeon, Sejong, and Jeonbuk, which showed significant improvement. The national AAPCs for annual screening rates for diabetic eye disease and kidney disease complications were 1.82 (0.99-2.66) and 1.95 (0.60-3. 41), respectively, and the area with the largest change was Sejong. Conclusions In Korea, the diabetes management indices tended to increase and improve, but the trends among provinces varied. Therefore, efforts are needed to address regional disparities in diabetes management.

We investigated whether endurance exercise training (EXT) ameliorates circadian rhythm (CR)-induced risk factors by improving skeletal muscle (SKM) mitochondrial biogenesis, reducing oxidative stress, and modulating apoptotic protein expression. We distinguished between regular and shift workers using the National Health and Nutrition Examination Survey (NHANES) and investigated the health problems caused by shift work (CR disturbance) and the potential therapeutic effects of exercise. In our animal study, 36 rats underwent 12 weeks of CR disturbance, divided into regular and irregular CR groups. These groups were further split into EXT (n = 12) and sedentary (n = 12) for an additional 8 weeks. We analyzed SKM tissue to understand the molecular changes induced by CR and EXT. NHANES data were analyzed using SAS 9.4 and Prism 8 software, while experimental animal data were analyzed using Prism 8 software. The statistical procedures used in each experiment are indicated in the figure legends. Our studies showed that CR disturbance increases dyslipidemia, alters circadian clock proteins (BMAL1, PER2), raises apoptotic protein levels, and reduces mitochondrial biogenesis in SKM. EXT improved LDL-C and HDLC levels without affecting muscle BMAL1 expression. It also enhanced mitochondrial biogenesis (AMPK, PGC-1α, Tfam, NADH-UO, COX-I), antioxidant levels (Catalase, SOD1, SOD2), and apoptotic protein (p53, Bax/Bcl2) expression or activity in SKM. We demonstrated that shift work-induced CR disturbance leads to dyslipidemia, diminished mitochondrial biogenesis, and reduced antioxidant capacity in SKM. However, EXT can counteract dyslipidemia under CR disturbance, potentially lowering the risk of cardiovascular disorders.

Purpose: This study aimed to determine whether micro-flow imaging (MFI) offers diagnostic performance comparable to that of contrast-enhanced ultrasonography (CEUS) in detecting segmental congestion among patients undergoing living donor liver transplantation (LDLT). Methods: Data from 63 patients who underwent LDLT between May and December 2022 were retrospectively analyzed. MFI and CEUS data collected on the first postoperative day were quantified. Segmental congestion was assessed based on imaging findings and laboratory data, including liver enzymes and total bilirubin levels. The reference standard was a postoperative contrast-enhanced computed tomography scan performed within 2 weeks of surgery. Additionally, a subgroup analysis examined patients who underwent reconstruction of the middle hepatic vein territory. Results: The sensitivity and specificity of MFI were 73.9% and 67.5%, respectively. In comparison, CEUS demonstrated a sensitivity of 78.3% and a specificity of 75.0%. These findings suggest comparable diagnostic performance, with no significant differences in sensitivity (P=0.655) or specificity (P=0.257) between the two modalities. Additionally, early postoperative laboratory values did not show significant differences between patients with and without congestion. The subgroup analysis also indicated similar diagnostic performance between MFI and CEUS. Conclusion MFI without contrast enhancement yielded results comparable to those of CEUS in detecting segmental congestion after LDLT. Therefore, MFI may be considered a viable alternative to CEUS.

Background: It is well known that a large number of patients with diabetes also have dyslipidemia, which significantly increases the risk of cardiovascular disease (CVD). This study aimed to evaluate the efficacy and safety of combination drugs consisting of metformin and atorvastatin, widely used as therapeutic agents for diabetes and dyslipidemia. Methods: This randomized, double-blind, placebo-controlled, parallel-group and phase III multicenter study included adults with glycosylated hemoglobin (HbA1c) levels >7.0% and <10.0%, low-density lipoprotein cholesterol (LDL-C) >100 and <250 mg/dL. One hundred eighty-five eligible subjects were randomized to the combination group (metformin+atorvastatin), metformin group (metformin+atorvastatin placebo), and atorvastatin group (atorvastatin+metformin placebo). The primary efficacy endpoints were the percent changes in HbA1c and LDL-C levels from baseline at the end of the treatment. Results: After 16 weeks of treatment compared to baseline, HbA1c showed a significant difference of 0.94% compared to the atorvastatin group in the combination group (0.35% vs. −0.58%, respectively; P<0.0001), whereas the proportion of patients with increased HbA1c was also 62% and 15%, respectively, showing a significant difference (P<0.001). The combination group also showed a significant decrease in LDL-C levels compared to the metformin group (−55.20% vs. −7.69%, P<0.001) without previously unknown adverse drug events. Conclusion The addition of atorvastatin to metformin improved HbA1c and LDL-C levels to a significant extent compared to metformin or atorvastatin alone in diabetes and dyslipidemia patients. This study also suggested metformin’s preventive effect on the glucose-elevating potential of atorvastatin in patients with type 2 diabetes mellitus and dyslipidemia, insufficiently controlled with exercise and diet. Metformin and atorvastatin combination might be an effective treatment in reducing the CVD risk in patients with both diabetes and dyslipidemia because of its lowering effect on LDL-C and glucose.

Background and objectives: This study aimed to analyze and present updated trends in atrial fibrillation (AF) epidemiology within the Korean population, providing a foundation for planning and implementing appropriate management and treatment strategies for patients with AF. Patients and methods: We used the Korean National Health Insurance Service database to evaluate the prevalence, incidence, comorbidities, and clinical adverse outcomes of patients with AF in Korea between 2013 and 2022. Results: AF prevalence in Korean adults aged ≥ 20 years doubled (1.1 to 2.2%) between 2013 and 2022, with significant increases observed across various sex and age groups. Similarly, the number of newly diagnosed patients with AF per year increased steadily, with the incidence rising from 184 to 275 per 100,000 person-years, particularly among older populations. Over this period, the mean age of patients with AF increased from 67.7 to 70.3 years, and comorbidities prevalence and CHA2DS2-VASc score rose significantly, indicating a higher stroke risk. Compared with patients without AF, AF was associated with an increased risk of mortality (hazard ratio [HR]: 1.78), ischemic stroke (HR: 2.39), major bleeding (HR: 2.10), myocardial infarction (HR: 1.44), and heart failure admission (HR: 2.42). Conclusion AF prevalence and incidence have steadily increased between 2013 and 2022, with a more pronounced increase in older patients. Patients with AF are increasingly becoming a high-risk population and are at increased risk of clinical adverse outcomes compared to non-AF patients. Therefore, a sustained national effort to improve AF awareness and comprehensive care quality for patients with AF is required.

In the 2023–2024 season, the influenza epidemic in South Korea peaked earlier than in recent years. In this study, we aimed to estimate the interim vaccine effectiveness (VE) of the influenza vaccination to prevent influenza during the early season. From November 1, 2023, to December 31, 2023, we enrolled 2,632 subjects with influenza-like illness from eight hospitals participating in hospital-based influenza morbidity and mortality surveillance. A retrospective test-negative case-control study was conducted to estimate the VE. The results showed an adjusted VE of 22.5% (95% confidence interval [CI], 6.6 to 35.8) for the total population. The adjusted VE was 22.3% (95% CI, 6.1 to 35.7) for influenza A and 9.4% (95% CI, −51.3 to 45.7) for influenza A/H1N1. Full results of the analysis will be reported.

Background: Bivalent booster mRNA vaccines containing the omicron-variant strains have been introduced worldwide in the autumn of 2022. Nevertheless, the omicron subvariants evoked another large coronavirus disease 2019 (COVID-19) pandemic wave in late 2022 and early 2023. Methods: A retrospective, test-negative, case-control study was conducted to estimate the vaccine effectiveness (VE) of bivalent COVID-19 vaccines in 8 university hospitals between January and February 2023. The case and control groups were divided based on nasopharyngeal COVID-19 real-time polymerase chain reaction results and matched based on age, sex, hospital, and date (week) of the test performed. The VE of the BA.1- or BA.4/BA.5-based mRNA vaccines were estimated. VE was calculated using the 1−adjusted odds ratio from multivariable logistic regression. Results: In total, 949 patients and 947 controls were enrolled in this study. VE for the BA.4/ BA.5-based bivalent mRNA vaccine was 43% (95% confidence interval [CI], 17, 61%). In subgroup analysis based on age and underlying medical conditions, BA.4/BA.5-based bivalent mRNA vaccine was effective against old adults aged ≥ 65-years (VE, 55%; 95% CI, 23, 73%) and individuals with comorbidities (VE, 54%; 95% CI, 23, 73%). In comparison, the BA.1-based bivalent mRNA vaccine did not demonstrate statistically significant effectiveness (VE, 25%; 95% CI, −8, 49%). Conclusion The BA.4/BA.5-based bivalent mRNA booster vaccine provided significant protection against COVID-19 in the Korean adults, especially in the older adults aged ≥ 65 years and in individuals with underlying medical conditions.