Exploring the Genetic Diversity and Molecular Evolution of Seoul and Hantaan Orthohantaviruses.

Seoul (SEOV) and Hantaan (HTNV) orthohantaviruses are significant zoonotic pathogens responsible for hemorrhagic fever with renal syndrome. Here, we investigated the molecular evolution of SEOV and HTNV through phylogenetic and bioinformatic analyses using complete genome sequences of their large (L), medium (M), and small (S) gene segments. Despite similar epizootic cycles and clinical symptoms, SEOV and HTNV exhibited distinct genetic and evolutionary dynamics. The phylogenetic trees of each segment consistently showed major genetic clades associated with the geographical distribution of both viruses. Remarkably, SEOV M and S segments exhibit higher evolutionary rates, rapidly increasing genetic diversity, and a more recent origin in contrast to HTNV. Reassortment events were infrequent, but both viruses appear to utilize the M gene segment in genetic exchanges. SEOV favors the L or M segment reassortment, while HTNV prefers the M or S segment exchange. Purifying selection dominates in all three gene segments of both viruses, yet SEOV experiences an elevated positive selection in its glycoprotein Gc ectodomain. Key amino acid differences, including a positive 'lysine fence' (through residues K77, K82, K231, K307, and K310) located at the tip of the Gn, alongside the physical stability around an RGD-like motif through M108-F334 interaction, may contribute to the unique antigenic properties of SEOV. With the increasing global dispersion and potential implications of SEOV for the global public health landscape, this study highlights the unique evolutionary dynamics and antigenic properties of SEOV and HTNV in informing vaccine design and public health preparedness.

Physical Activity Pattern of Adults With Metabolic Syndrome Risk Factors: Time-Series Cluster Analysis.

Background: Physical activity plays a crucial role in maintaining a healthy lifestyle, and wrist-worn wearables, such as smartwatches and smart bands, have become popular tools for measuring activity levels in daily life. However, studies on physical activity using wearable devices have limitations; for example, these studies often rely on a single device model or use improper clustering methods to analyze the wearable data that are extracted from wearable devices. Objective: This study aimed to identify methods suitable for analyzing wearable data and determining daily physical activity patterns. This study also explored the association between these physical activity patterns and health risk factors. Methods: People aged >30 years who had metabolic syndrome risk factors and were using their own wrist-worn devices were included in this study. We collected personal health data through a web-based survey and measured physical activity levels using wrist-worn wearables over the course of 1 week. The Time-Series Anytime Density Peak (TADPole) clustering method, which is a novel time-series method proposed recently, was used to identify the physical activity patterns of study participants. Additionally, we defined physical activity pattern groups based on the similarity of physical activity patterns between weekdays and weekends. We used the χ2 or Fisher exact test for categorical variables and the 2-tailed t test for numerical variables to find significant differences between physical activity pattern groups. Logistic regression models were used to analyze the relationship between activity patterns and health risk factors. Results: A total of 47 participants were included in the analysis, generating a total of 329 person-days of data. We identified 2 different types of physical activity patterns (early bird pattern and night owl pattern) for weekdays and weekends. The physical activity levels of early birds were less than that of night owls on both weekdays and weekends. Additionally, participants were categorized into stable and shifting groups based on the similarity of physical activity patterns between weekdays and weekends. The physical activity pattern groups showed significant differences depending on age (P=.004) and daily energy expenditure (P<.001 for weekdays; P=.003 for weekends). Logistic regression analysis revealed a significant association between older age (≥40 y) and shifting physical activity patterns (odds ratio 8.68, 95% CI 1.95-48.85; P=.007). Conclusions: This study overcomes the limitations of previous studies by using various models of wrist-worn wearables and a novel time-series clustering method. Our findings suggested that age significantly influenced physical activity patterns. It also suggests a potential role of the TADPole clustering method in the analysis of large and multidimensional data, such as wearable data.

Predicting Habitual Use of Wearable Health Devices Among Middle-aged Individuals With Metabolic Syndrome Risk Factors in South Korea: Cross-sectional Study.

BACKGROUND: Prevention of the risk factors for metabolic syndrome (MetS) in middle-aged individuals is an important public health issue. Technology-mediated interventions, such as wearable health devices, can aid in lifestyle modification, but they require habitual use to sustain healthy behavior. However, the underlying mechanisms and predictors of habitual use of wearable health devices among middle-aged individuals remain unclear. OBJECTIVE: We investigated the predictors of habitual use of wearable health devices among middle-aged individuals with risk factors for MetS. METHODS: We proposed a combined theoretical model based on the health belief model, the Unified Technology of Acceptance and Use of Technology 2, and perceived risk. We conducted a web-based survey of 300 middle-aged individuals with MetS between September 3 and 7, 2021. We validated the model using structural equation modeling. RESULTS: The model explained 86.6% of the variance in the habitual use of wearable health devices. The goodness-of-fit indices revealed that the proposed model has a desirable fit with the data. Performance expectancy was the core variable explaining the habitual use of wearable devices. The direct effect of the performance expectancy on habitual use of wearable devices was greater (ß=.537, P<.001) than that of intention to continue use (ß=.439, P<.001), and the total effect estimate of the performance expectancy was 0.909 (P<.001), including the indirect effect (ß=.372, P=.03) on habitual use of wearable devices via intention to continue use. Furthermore, performance expectancy was influenced by health motivation (ß=.497, P<.001), effort expectancy (ß=.558, P<.001), and risk perception (ß=.137, P=.02). Perceived vulnerability (ß=.562, P<.001) and perceived severity (ß=.243, P=.008) contributed to health motivation. CONCLUSIONS: The results suggest the importance of the users' performance expectations for wearable health devices for the intention of continued use for self-health management and habituation. Based on our results, developers and health care practitioners should find better ways to meet the performance expectations of middle-aged individuals with MetS risk factors. They also should generate device use easier and find a way to encourage users' health motivation, thereby reducing users' effort expectancy and resulting in a reasonable performance expectancy of the wearable health device, to induce users' habitual use behaviors.

Phylodynamic analysis revealed that human mobility and vaccination were correlated to the local spread of SARS-CoV-2 in Republic of Korea.

Following the global emergence of the SARS-CoV-2 Alpha variant of concern (VOC) in 2020, the Delta variant triggered another wave in 2021. The AY.69 lineage, a Delta VOC, was particularly prevalent in Republic of Korea (South Korea) from May 2021 to January 2022, despite the synchronized implementation of vaccination programmes and non-pharmaceutical interventions (NPIs) such as social distancing. In this study, we used phylogeographic analysis combined with a generalized linear model (GLM) to examine the impact of human movement and vaccination on viral transmission. Our findings indicated that transmission primarily originated in South Korea's metropolitan areas, and a positive correlation was observed between total human mobility (tracked by GPS on mobile phones and estimated through credit card consumption) and viral spread. The phylodynamic analysis further revealed that non-vaccinated individuals were the primary transmitters of the virus during the study period, even though vaccination programmes had commenced three months prior to the AY.69 outbreak. Our study emphasizes the need to focus on controlling SARS-CoV-2 transmission in metropolitan regions and among unvaccinated populations. Furthermore, the positive correlation between mobility data and viral dissemination could contribute to the development of more accurate predictive models for local spread of pandemics.

Trends in pneumonia and influenza-associated hospitalizations in South Korea, 2002-2005.

Pneumonia and influenza are leading causes of morbidity and mortality across the globe. Korea has established the national health-insurance system to cover the entire Korean population since 1989. The aim of this study was to describe the epidemiologic trends in pneumonia and influenza-associated hospitalizations and deaths using the Korean National Health Insurance databases and national vital statistics. During 2002-2005, 989,472 hospitalizations and 10,543 deaths due to pneumonia and influenza were recorded. Eighty-one percent of the hospitalizations were related to diagnoses with unspecified aetiology. The average annual rate of hospitalizations due to pneumonia and influenza was 5.2 per 1,000 people [95% confidence interval (CI) 5.2-5.3], and the hospitalization rate increased by 28% (from 4.5 to 5.8 per 1,000 people) during the four-year study period. In addition, deaths due to pneumonia and influenza increased by 48% (2,829 during 2003, 3,522 during 2004, and 4,192 during 2005). Overall, the national burden of hospitalizations and deaths due to pneumonia and influenza in Korea was high, and it increased for all age-groups during the study period. A comprehensive review of potential interventions by the government authorities should aim to reduce the burden of pneumonia and influenza.

Inequalities in medical care utilization by South Korean cancer patients according to income: a retrospective cohort study.

This study explores income inequalities in the utilization of medical care by cancer patients in South Korea, according to type of medical facilities and survival duration. The five-year retrospective cohort study used data drawn from the Korean Cancer Registry, the National Health Insurance database, and the death database of the Korean National Statistical Office. The sample consisted of 43,433 patients diagnosed with cancer in 1999. The authors found significant quantitative inequalities as a function of income in the patients' utilization of medical care. Cancer patients from the highest income class used inpatient and outpatient care more frequently than did patients from the lowest income class. Those with higher incomes tended to use more inpatient and outpatient services at major tertiary hospitals, which were known as providing better medical care than other types of hospitals and clinics. Moreover, horizontal inequality in cancer-care expenditures favoring those with higher incomes was observed during earlier periods of treatment. In conclusion, income substantially affects the utilization of inpatient and outpatient services, amount of medical expenditures, and type of medical facilities.

Body-mass index and mortality in Korean men and women.

BACKGROUND: Obesity is associated with diverse health risks, but the role of body weight as a risk factor for death remains controversial. METHODS: We examined the association between body weight and the risk of death in a 12-year prospective cohort study of 1,213,829 Koreans between the ages of 30 and 95 years. We examined 82,372 deaths from any cause and 48,731 deaths from specific diseases (including 29,123 from cancer, 16,426 from atherosclerotic cardiovascular disease, and 3362 from respiratory disease) in relation to the body-mass index (BMI) (the weight in kilograms divided by the square of the height in meters). RESULTS: In both sexes, the average baseline BMI was 23.2, and the rate of death from any cause had a J-shaped association with the BMI, regardless of cigarette-smoking history. The risk of death from any cause was lowest among patients with a BMI of 23.0 to 24.9. In all groups, the risk of death from respiratory causes was higher among subjects with a lower BMI, and the risk of death from atherosclerotic cardiovascular disease or cancer was higher among subjects with a higher BMI. The relative risk of death associated with BMI declined with increasing age. CONCLUSIONS: Underweight, overweight, and obese men and women had higher rates of death than men and women of normal weight. The association of BMI with death varied according to the cause of death and was modified by age, sex, and smoking history.

Body mass index and serum aminotransferase levels in Korean men and women.

BACKGROUND AND AIMS: Obesity has been postulated as contributing to the risk of nonalcoholic steatohepatitis. With the surging obesity epidemic, an ensuing epidemic of nonalcoholic steatohepatitis and its sequelae is of concern. The objectives of this clinical research study were to examine the association between body mass index (BMI) and serum aminotransferase levels. METHOD: A study was carried out on 1,166,847 Koreans (731,560 men and 435,287 women), 30 to 95 years of age, who received health insurance from the National Health Insurance Corp and had a biennial medical evaluation from 1992 to 1995. RESULTS: Across the range of BMI values (<18.5 to >or=32 kg/m) in men, alanine aminotransferase (ALT) was estimated to increase by 18.8 U/L and aspartate aminotransferase (AST) increased by 7.1 U/L. In women, ALT increased by 9.9 U/L, whereas AST increased by 4.5 U/L. In men, interactions between BMI and alcohol consumption were significant (P<0.001) for ALT and AST, but the degree of effect modification was quantitatively minor. However, ALT and AST levels were somewhat higher in heavy alcohol drinkers than in nondrinkers. For women, the relationship of aminotransferase levels with BMI did not vary by alcohol consumption. The relationship of BMI with aminotransferase weakened with increasing age. CONCLUSIONS: In Korea, ALT and AST are strongly associated with BMI and increased progressively from the lowest to the highest strata of BMI. The association of BMI with aminotransferase levels was modified by age and sex.

Caregiver burden among caregivers of Koreans with dementia.

BACKGROUND: Most studies on caregiver burden have been conducted in Western countries, while few studies on the correlates of caregiver burden have been performed in Korea. OBJECTIVE: To suggest better policies for the care of dementia patients by using a nationwide database to identify factors that affect caregiver burden in Korea. METHODS: The database of the Korean National Health Insurance (KNHI) and National Medical Aid (NMA) programs, which covers all Koreans, was used. A sample of 609 dementia patients and their caregivers was selected from a total of 85,281 dementia patients in 2004 and interviewed to evaluate the total cost of care and caregiver burden. Stepwise multiple linear regression analysis was then performed to identify significant independent predictors of caregiver burden. RESULTS: Among caregiver-related factors, caregiver burden was higher in those who were female, had a history of home care during the previous year, and had less education. Among patient-related factors, poor ADL/IADL function was significant. The most interesting result was that subjective sense of socioeconomic status (good/fair/poor) was a stronger predictor of caregiver outcome than actual economic costs. CONCLUSION: The results of this study suggest that interventions to assist patients with dementia should focus on female caregivers, especially those considered likely to be suffering from an economic burden. Interventions should also aim to improve the ADL and IADL capacities of patients.

Pancreatic cancer and factors associated with the insulin resistance syndrome in the Korean cancer prevention study.

There is increasing evidence that type 2 diabetes mellitus and glucose intolerance are a cause, not just a consequence, of pancreatic cancer. We examined whether other factors that characterize the insulin resistance syndrome are also risk factors for pancreatic cancer in a prospective cohort study of 631,172 men and women (ages 45+ years) who received health insurance from the Korean Medical Insurance Corporation. The biennial medical evaluations from 1992 to 1995 provided the baseline information for this study. Relative risks (RR) were estimated using proportional hazards models adjusted for age, sex, smoking, and fasting serum glucose (after excluding the first 2 years of follow-up). There were 2,194 incident cases of pancreatic cancer diagnosed in the cohort over a median follow-up of 12 years. There was no evidence that pancreatic cancer risk was associated with total cholesterol, systolic blood pressure, WBC count, or body mass index. Abnormal levels of aspartate aminotransferase and alanine aminotransferase were both associated with a moderately increased risk of developing the disease (40+ versus <20; RR, 1.33; 95% CI, 1.14-1.55; P(trend) = 0.05 and RR, 1.34; 95% CI, 1.16-1.56; P(trend) = 0.02, respectively). Excluding 6 years of follow-up reduced this RR (95% CI) for aspartate aminotransferase to 1.22 (1.01-1.49), but even after excluding 10 years follow-up the RR (95% CI) for alanine aminotransferase was unchanged [1.36 (1.01-1.83)]. Although fasting serum glucose has been found previously to be associated with pancreatic cancer risk in this cohort, most other factors that characterize insulin resistance syndrome were not associated with pancreatic cancer risk. The association with elevated liver enzyme levels is a novel finding that warrants further investigation.