Associations between indoor volatile organic compounds and nocturnal heart rate variability of young female adults: A panel study / 北京大学学报(医学版)

OBJECTIVE@#To investigate the association between short-term exposure to indoor total volatile organic compounds (TVOC) and nocturnal heart rate variability (HRV) among young female adults.@*METHODS@#This panel study recruited 50 young females from one university in Beijing, China from December 2021 to April 2022. All the participants underwent two sequential visits. During each visit, real time indoor TVOC concentration was monitored using an indoor air quality detector. The real time levels of indoor temperature, relative humidity, noise, carbon dioxide and fine particulate matter were monitored using a temperature and humidity meter, a noise meter, a carbon dioxide meter and a particulate counter, respectively. HRV parameters were measured using a 12-lead Holter. Mixed-effects models were used to evaluate the association between the TVOC and HRV parameters and establish the exposure-response relationships, and two-pollutant models were applied to examine the robustness of the results.@*RESULTS@#The mean age of the 50 female subjects was (22.5±2.3) years, and the mean body mass index was (20.4±1.9) kg/m2. During this study, the median (interquartile range) of indoor TVOC concentrations was 0.069 (0.046) mg/m3, the median (interquartile range) of indoor temperature, relative humidity, carbon dioxide concentration, noise level and fine particulate matter concentration were 24.3 (2.7) ℃, 38.5% (15.0%), 0.1% (0.1%), 52.7 (5.8) dB(A) and 10.3 (21.5) μg/m3, respectively. Short-term exposure to indoor TVOC was associated with significant changes in time-domain and frequency-domain HRV parameters, and the exposure metric for most HRV parameters with the most significant changes was 1 h-moving average. Along with a 0.01 mg/m3 increment in 1 h-moving average concentration of indoor TVOC, this study observed decreases of 1.89% (95%CI: -2.28%, -1.50%) in standard deviation of all normal to normal intervals (SDNN), 1.92% (95%CI: -2.32%, -1.51%) in standard deviation of average normal to normal intervals (SDANN), 0.64% (95%CI: -1.13%, -0.14%) in percentage of adjacent NN intervals differing by more than 50 ms (pNN50), 3.52% (95%CI: -4.30%, -2.74%) in total power (TP), 5.01% (95%CI: -6.21%, -3.79%) in very low frequency (VLF) power, and 4.36% (95%CI: -5.16%, -3.55%) in low frequency (LF) power. The exposure-response curves showed that indoor TVOC was negatively correlated with SDNN, SDANN, TP, and VLF when the concentration exceeded 0.1 mg/m3. The two-pollutant models indicated that the results were generally robust after controlling indoor noise and fine particulate matter.@*CONCLUSION@#Short-term exposure to indoor TVOC was associated with significant negative changes in nocturnal HRV of young women. This study provides an important scientific basis for relevant prevention and control measures.

Acute effect of ambient fine particulate matter on heart rate variability: an updated systematic review and meta-analysis of panel studies

BACKGROUND@#Decreased heart rate variability (HRV) is a predictor of autonomic system dysfunction, and is considered as a potential mechanism of increased risk of cardiovascular disease (CVD) induced by exposure to particulate matter less than 2.5 μm in diameter (PM@*METHODS@#An updated systematic review and meta-analysis of panel studies till November 1, 2019 was conducted to evaluate the acute effect of exposure to ambient PM@*RESULTS@#A total of 33 panel studies were included in our meta-analysis, with 16 studies conducted in North America, 12 studies in Asia, and 5 studies in Europe. The pooled results showed a 10 μg/m@*CONCLUSION@#Short-term exposure to PM

Longitudinal Panel Study of Sports Injuries in University Elite Athletes / 대한스포츠의학회지

PURPOSE: The first aim of this study was to retrospectively survey sports injuries among 608 athletes participating in 26 sport events. The second aim was to compare the characteristics of sports injuries depending on the occurrences during the high school and university periods.METHODS: The data were collected based on the daily injury report form proposed by the International Olympic Committee from March to June 2019.RESULTS: Four hundred and thirty-nine athletes (313 men) of 608 participated athletes experienced a total of 747 sports injuries, indicating 0.7 injuries per 1,000 athlete exposures (AEs). The incidence rate during the university period was 6.1 injuries/1,000 AEs, which was approximately two-fold higher than that during the high school period (2.8 injuries/1,000 AEs). The reported frequency of injuries was the highest among long distance athletics (n=60, 8.0%), and in each subgroup as well.CONCLUSION: Many more injuries were incurred during practice wherein injuries in long-distance athletics were the most common than in competition athletics; handball injuries and taekwondo injuries were the most common during high school and university, respectively. The most contact injuries occurred in taekwondo and most noncontact injuries occurred in gymnastics during high school and in badminton during university. The most commonly affected body parts were the knee, shoulder, and ankle. Severe injuries were the most frequent in long distance athletics, and emergent situations were the most common in taekwondo.

Joint Association of Screen Time and Physical Activity with Obesity: Findings from the Korea Media Panel Study

OBJECTIVES: There is evidence to suggest that sedentary behavior is associated with a higher risk of metabolic disease. The aim of this study was to investigate cross-sectional joint associations of physical activity (PA) and screen time (ST), with the risk of obesity in Korean adults. METHODS: The Korea Media Panel Study consisted of a household interview and a self-administered diary survey on media usage over 3 days. ST (hours/day) was defined as the reported daily average hours spent watching television, computing (i.e., desktop, notebook, netbook, tablets), smartphone and video game console use. Cross-sectional associations of obesity (BMI ≥ 25 kg/m2) and the amount of daily ST and PA were examined by logistic regression models adjusting for other possible confounders including alcohol consumption, smoking, depressive symptoms and demographic information. There were 7,808 participants included in the analyses. RESULTS: Increased ST was significantly associated with the risk of obesity (controlling for other possible confounders), but PA level was not found to be significantly linked. Participants who engaged in screen time > 6 hours per day had a higher incidence of obesity. CONCLUSION: This study provides evidence of the association between ST and the increased incidence of obesity measured by BMI, independent of PA amongst Korean adults.

A Panel Study on the Determinants of the Regional Variation in the Rate of Certification in Long-Term Care Insurance / 보건행정학회지

BACKGROUND: There have been deviations in the regional rate of certification in Korean long-term care insurance (LTCI). This study aimed to explore the determinants of the rate of certification in LTCI. METHODS: The panel data of the year 2010–2014 of the 227 National Health Insurance Service (NHIS) regional office were used. Making use of 26 explanatory variables (socio-demographic factors, access to the long-term care services, etc.), we estimated the random effects model using STATA SE ver. 13.0 program (Stata Corp., College Station, TX, USA) and tried to find out the determinants of the regional rate of certification. RESULTS: Estimation results showed that the most important determinants of the regional rate of certification in LTCI are the long-term care infrastructure such as capacity or number of the homecare service institution, sanatorium, or convalescent hospital. The number of the elderly who lives alone and the dimentia patients were positively related to the regional rate of certification in LTCI. CONCLUSION: The estimation results implied that the regional variation in the rate of certification in LTCI has nothing to do with the NHIS regional offices or their employees. To alleviate the deviation in the regional rate of certification in LTCI, we suggested the analysis of the deviation in the survey checklist. We also proposed to found the regional comprehensive support center to prevent the geriatric illness and to improve the residents' health, etc.

An Analysis on the Determinants of Efficiency of the Pharmaceutical Firms using Stochastic Frontier Analysis / 보건행정학회지

BACKGROUND & METHODS: The purpose of this research is to estimate the efficiency of the pharmaceutical firms and the determinants of their efficiency. Stochastic frontier analysis(SFA) and panel study are applied to the data of 60 domestic pharmaceutical firms from 2006 to 2012. RESULTS & CONCLUSION: First, the result of the stochastic frontier analysis shows that overall efficiency of the pharmaceutical firms is increasing as time goes by. However, if firms are classified by the scale, the larger firms show more efficiency and if classified by the degree of innovativeness, the innovative firms show more efficiency compared to the non-innovative firms. This evidences show that the scale and R&D investment have significant relationships with the efficiency of the pharmaceutical firms. Therefore, it is necessary to increase the national level of investment for the fundamental researches to vitalize R&D of the new drugs. Second, the result of estimation of the determinants of efficiency shows that the firms with larger sales promotion expenses and entertainment expenses have less efficiency compared to the other firms. This can be explained by the structural characteristics of the small generic pharmaceutical firms. Therefore, the government had better make the pharmaceutical firms to reduce sales promotion and entertainment expenses and increase R&D expenses by introducing systems such as global budgeting system on medicine or reference pricing system.

The effects of individual, occupational, and supportive factors on successful return to work using a structural equation model

OBJECTIVES: We aimed to ascertain the relationship between several factors and successful return to work using a structural equation model. METHODS: We used original data from the Panel Study of Worker's Compensation Insurance, and defined four latent variables as occupational, individual, supportive, and successful return to work. Each latent variable was defined by its observed variables, including age, workplace size, and quality of the medical services. A theoretical model in which all latent variables had a relationship was suggested. After examining the model, we modified some pathways that were not significant or did not fit, and selected a final structural equation model that had the highest goodness of fit. RESULTS: All three latent variables (occupational, individual, and supportive) showed statistically significant relationships with successful return to work. The occupational and supportive factors had relationships with each other, but there was no relationship between individual and the other factors. Nearly all observed variables had significance with their latent variables. The correlation coefficients from the latent variables to successful return to work were statistically significant and the indices for goodness of fit were satisfactory. In particular, four observed variables-handicap level, duration of convalescence, working duration, and support from the company-showed construct validities with high correlation coefficients. CONCLUSIONS: All factors that we examined are related to successful return to work. We should focus on the supportive factor the most because its variables are modifiable to promote a return to work by those injured in their workplace.

A Panel Study on the Effect of Obesity and the Chronic Diseases on the Health Care Expenditures / 보건행정학회지

We analyze the determinants of obesity and the chronic diseases using the Korea Health Panel data. Also we analyze the effect of obesity and the chronic diseases on the health care expenditures. Through this study, to reduce the health care expenditures, we suggest the policy implication that might curb the obesity and the chronic diseases. We estimate the determinants of obesity, the chronic diseases, and the health care expenditures using 2SLS (two stage least squares) estimation method under the simultaneous equations framework. Result says that obesity and chronic diseases significantly have positive effects on the health care expenditures. Also the determinants of the health care expenditures that have positive effects are age, income and health care utilization variables.

Relationship between ambient fine particles and ventricular repolarization changes and heart rate variability of elderly people with heart disease in Beijing, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To explore the effects of particulate matters less than 2.5 μm in aerodynamic diameter (PM2.5) on heart repolarization/depolarization and heart rate variability (HRV).</p><p><b>METHODS</b>We conducted a panel study for elderly subjects with heart disease in Beijing from 2007 to 2008. PM2.5 was measured at a fixed station for 20 h continuously each day while electrocardiogram (ECG) indexes of 42 subjects were also recorded repeatedly. Meteorological data was obtained from the China Meteorological Data Sharing Service System. A mixed linear regression model was used to estimate the associations between PM2.5 and the ECG indexes. The model was adjusted for age, body mass index, sex, day of the week and meteorology.</p><p><b>RESULTS</b>Significant adverse effects of PM2.5 on ECG indexes reflecting HRV were observed statistically and the strongest effect of PM2.5 on HRV was on lag 1 day in our study. However, there were no associations between PM2.5 and ECG indexes reflecting heart repolarization/depolarization. Additionally, the effects of PM2.5 on subjects with hypertension were larger than on the subjects without hypertension.</p><p><b>CONCLUSION</b>This study showed ambient PM2.5 could affect cardiac autonomic function of the elderly people with heart disease, and subjects with hypertension appeared to be more susceptive to the autonomic dysfunction induced by PM2.5.</p>

Effect of Vehicle Exhaust Pollution on Lung Function and Inflammatory Factors Level in Pupils / 环境与健康杂志

Objective To explore whether pollutants exposure has a measurable impact on lung function and inflammatory factors level of healthy pupils in vehicle exhaust polluted region. Methods Primary school near the trunk road with a distance no more than 30 meters was selected,and 50 qualified pupils were chosen. A time-series panel study was conducted with these pupils,and the following consecutive five days'study of vehicle exhaust pollution level,3-days’personal exposure measurement and its health effects were carried out in May and November in 2008. Results The main pollutant in this region was motor vehicle exhaust. Compared to May,the value of FVC% declined significantly in November(P=0.02) . And the reduction of the value of FVC% was negatively associated with an increase in NO2 concentrations(P=0.04) . The levels of IL-2,IL-6,IL-8 became lower in November compared with May,and were negatively associated with personal exposure with IL-6 with statistically significant difference(?PM10=-0.62,?NO2=-0.62,?O3=-0.64,?SO2=-0.63) . The levels of TNF-? and IL-4 were positively associated with personal exposure,in which PM10 has the largest regression coefficient with TNF-?(?=0.65,P