Few studies have shown the combined impact of sitting time and physical activity on quality of life in older people. This cross-sectional study, using data from the 2016–2018 Korean National Health and Nutrition Examination Survey, examines the association between sitting time and physical activity and health-related quality of life (HRQoL) in Korean adults aged ≥ 65 years. HRQoL was assessed using the EuroQol-5 Dimension (EQ-5D, three-level version). We divided subjects into groups based on sitting time and physical activity and analyzed the combined association of sitting time and physical activity with HRQoL. The association between longer sitting time (≥8 h) and HRQoL was analyzed using multiple logistic regression. In total, 4276 participants were included. Prolonged sitting time was associated with all of the EQ-5D dimensions: mobility (odds ratio [OR]: 1.43, 95% confidence interval [CI]: 1.22–1.68), self-care (OR: 1.65 [95% CI 1.25–2.17]), usual activities (OR: 2.07 [95% CI 1.69–2.52]), pain/discomfort (OR: 1.57 [95% CI 1.34–1.84]), and anxiety/depression (OR: 1.49 [95% CI 1.17–1.91]). The prolonged sitting time/inactive group had higher ORs for all the EQ-5D dimensions than the low sitting time/active group. Prolonged sitting time was associated with low HRQoL in elderly Korean adults; physical activity could weaken the negative influence of prolonged sitting time on HRQoL.

Grip strength is a convenient method to measure muscle strength. Recently, relative handgrip strength (HGS) was recommended as a clinical predictor of metabolic health and disease, such as dyslipidemia, which is considered a risk factor for cardiovascular disease. The purpose of this study was to characterize the association between relative HGS and dyslipidemia. We included 6,027 adults (2,934 men, 3,093 women) aged 30-69 years who participated in the Korea National Health and Nutrition Examination Survey in 2014 and 2015. Relative HGS was obtained by dividing the HGS by body mass index. Complex sampling analysis was conducted to compare the general characteristics of participants according to the quartiles of relative HGS. Logistic regression analysis was used to examine the association between quartiles of relative HGS and dyslipidemia. After adjustment for age, prevalence of diabetes mellitus, prevalence of hypertension, alcohol consumption, smoking status, exercise, income, and education level, relative HGS was inversely associated with dyslipidemia in both men and women. In multivariable logistic regression analysis, the odds ratios (95% confidence intervals) for dyslipidemia in quartiles 1, 2, and 3 relative to quartile 4 were 1.36 (1.00-1.83), 1.29 (0.98-1.70), 1.23 (0.95- 1.60) in men and 1.81 (1.30-2.50), 1.81 (1.32-2.47), 1.39 (1.07-1.81) in women, respectively. Relative HGS was inversely associated with dyslipidemia risk in Korean adults. Muscle-strengthening exercise is recommended to enhance health outcomes.

Insulin resistance contributes to the development of cardiovascular disease and type 2 diabetes mellitus. Smoking leads to an increase in triglyceride levels, which, in turn, increases insulin resistance. Although the number of e-cigarette users has increased in recent years, few studies have investigated the association between ecigarette use and insulin resistance. Therefore, this study aimed to determine the association between e-cigarette use and insulin resistance using the triglyceride-glucose (TyG) index in Korean adults. This study included 4,404 healthy adults aged ≥20 years who participated in the Korea National Health and Nutrition Examination Survey between 2019 and 2020. Participants were categorized as never-smokers or ecigarette users, and the TyG index was categorized into low- and high-TyG index groups according to the median value (9.22). A logistic regression analysis was performed to determine the association between e-cigarette smoking and insulin resistance. E-cigarette users had a higher TyG index than never smokers (e-cigarette: mean=3.95; never: mean=9.18; P<0.001). The e-cigarette users had a higher risk of being in the high TyG index group than never-smokers (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.03-1.84). In the subgroup analysis stratified by sex, age, and body mass index, a higher OR for a high TyG index was observed in men (OR, 1.46; 95% CI, 1.03-2.08) and individuals aged 60 years or older (OR, 3.74; 95% CI, 1.14-12.30). Our findings suggest that e-cigarette use is significantly associated with insulin resistance.

Background: Caffeine, a widely consumed stimulant, affects sleep and mental health. Shift work disrupts the circadian rhythm and has been associated with various mental health issues, such as depression, anxiety, and suicidal ideation. Objective: This study explored the associations between caffeine consumption, sleep duration, and mental health outcomes, particularly suicidal ideation, among shift workers in Korea. Methods: Data from the 6th Korea National Health and Nutrition Examination Survey (2013, 2015), which comprised 4723 adults aged 19 and older, were analyzed. Participants were categorized into groups based on average daily coffee consumption and work patterns. Multiple logistic regression analyses were conducted to determine the impact of caffeine consumption and work patterns on mental health outcomes. Results: Participants worked longer hours, reported higher perceived stress levels, and slightly decreased sleep duration as daily coffee consumption increased. However, no significant differences were observed in depression or suicidal ideation across the coffee consumption groups. Logistic regression analysis indicated a trend towards higher suicidal ideation risk with increased coffee intake, particularly among those who consumed three or more cups per day (OR 5.67, 95% CI 1.82–17.59). Conclusion: This study suggests a complex relationship between caffeine consumption, work patterns, and mental health outcomes. Although caffeine intake is associated with increased work hours and stress, its impact on suicidal ideation is influenced by occupational factors.

As indoor space becomes more important in our daily life, the demand to build digital twins for indoor spaces is increasing accordingly. The properties of indoor spaces, however, differ from those of outdoor spaces, and we need to apply different approaches to build indoor digital twins. In our work, we propose a framework for building an indoor digital twin with a use case for hospitals in general and large hospitals in particular, which may be considered as one of the most complicated types of digital twin. One of our goals is to establish a framework for building indoor digital twins based on standards and our framework starts from OGC IndoorGML, which is a standard for indoor data models and encoding schemes for indoor spatial data. In this paper, each step of the framework is presented for the construction of an indoor hospital digital twin focusing on a use case of epidemic analysis of COVID-19 transmission in a hospital. The use case study covers the entire life cycle of the indoor spatial application from requirement analysis, data modeling, and building indoor spatial data to the development of a COVID-19 transmission analysis. Our work represents a use case for indoor digital twins based on the OGC IndoorGML standard and eventually may serve as a framework and reference for building indoor digital twins. As our work is mainly focused on the construction of hospital digital twins, the study on COVID-19 infection model itself is limited in this paper. Improvement of the infection models and validations will be the next step of our work. As HVAC (heat, ventilation, and air conditioning) was not fully considered in our use case, we also expect that it is possible to strengthen our use case by including HVAC for the analysis of airflow dynamics.

Background: Sarcopenia is defined as the loss of muscle mass and strength and low physical performance, and it is closely related to the risk of cardiovascular disease and mortality. Pulse pressure (PP) is a biomarker of arterial stiffness and compliance. Elevated PP levels increase the risk of cardiovascular diseases and all-cause mortality. Nevertheless, the association between PP and sarcopenia has not yet been clearly established. Methods: Participant data were extracted from the Korea National Health and Nutrition Examination Survey conducted from 2014 to 2020. The study population was classified into three groups (PP < 40 mmHg, 40 mmHg ≤ PP < 60 mmHg, and PP ≥ 60 mmHg). PP was calculated by deducting the diastolic blood pressure from the systolic blood pressure. For handgrip strength, the maximum value measured with a grip dynamometer was adopted (weak handgrip strength: <28 kg for men, <18 kg for woman; normal handgrip strength: ≥28 kg for men, ≥18 kg for women). To determine the relationship between PP and the prevalence of weak handgrip strength, multiple logistic regression analysis was performed after adjusting for possible confounding factors. Results: The higher PP group had a higher age, body mass index; systolic blood pressure, prevalence of hypertension, diabetes, hyperlipidemia, and metabolic syndrome, and maximum handgrip strength. In all models, the prevalence of weak handgrip strength was significantly higher in the group with PP ≥ 60 mmHg compared to the control group (PP < 40 mmHg). Conclusions: Elevated PP was significantly associated with a higher prevalence of weak muscle strength. Thus, PP monitoring may be used to identify individuals at risk of sarcopenia and is helpful in improving health outcomes.