Moo-Sik Lee

Postprandial hypertriglyceridemia impairs endothelial function by enhanced oxidant stress

AIMS it appears that hypertriglyceridemia (HTG) is a risk factor of atherosclerosis as demonstrated by recent studies. In this study, we analyzed the effects of acute HTG on endothelial function and oxidative stress, which are important mechanisms in the pathogenesis of atherosclerosis. METHODS AND RESULTS in a high fat meal group (n = 11), serum triglycerides and PMA-activated leukocyte O(2)(-)* production were significantly (P < 0.005) increased from 146 +/- 69 mg/dl and 4.09 +/- 0.93 nmol/10(6) cells/min preprandially to 198 +/- 88 mg/dl and 5.49 +/- 1.19 nmol/10(6) cells/min, respectively, 2 h after eating a high-fat meal. The flow-mediated endothelium-dependent brachial artery dilation (FMD; high-resolution ultrasound) was decreased from 13.7 +/- 3.3% preprandially to 8.2 +/- 3.7%, 2 h after eating a high-fat meal (P < 0.005). However, following a low-fat meal (n = 9), there were no significant changes in triglycerides, leukocyte O(2)(-)* production and FMD. Changes of serum triglycerides were correlated negatively (r = -0.650, P < 0.005) with changes of FMD, but were correlated positively (r = 0.798, P < 0.001) with changes of leukocyte O(2)(-)* production, which - in turn - were correlated negatively (r = -0.784, P < 0.001) with changes of FMD in all study subjects (mean age: 56 years, n = 20). CONCLUSIONS this study suggests that acute HTG causes endothelial dysfunction via enhanced oxidant stress and this may pave the way for the development of atherosclerosis under chronic conditions.

Impact of postprandial hypertriglyceridemia on vascular responses in patients with coronary artery disease: effects of ACE inhibitors and fibrates

We analyzed vascular responses (endothelial function, oxidant stress) to postprandial hypertriglyceridemia (PHTG) in patients with coronary artery disease (CAD) to reveal potential therapeutical effects of angiotensin converting enzyme inhibition (ACE-I) and of lipid lowering (fibrate). The study population (n=39, mean age: 60 years) consisted of four groups, all of which had angiographically documented CAD. A high fat group (n=9) consumed a high fat meal, a low fat group (n=9) a low fat meal, and ACE-I (n=10) or fibrate (n=11) groups consumed a high fat meal plus lisinopril or fenofibrate. Serum triglycerides (TG) increased significantly 2 h after eating a test meal in all groups with the exception of the low fat group. In the high and low fat groups changes of serum TG were positively correlated (r=0.664, P<0.005) with changes of phorbol ester-activated leukocyte superoxide anion radical (O(2-.)) formation and were negatively correlated (r=-0.488, P<0.05) with flow-mediated brachial artery dilation (FMD). There was a negative correlation (r=-0.419, P=0.094) between FMD and changes of O(2-.) formation in the high and low fat groups. In the ACE-I and fibrate groups, O(2-.) formation decreased 2 h after eating a test meal (from 5.34+/-1.01 to 3.81+/-1.15 nmol/10(6)cells per min, P<0.01, and from 4.66+/-0.91 to 4.26+/-0.97 nmol/10(6)cells per min, P=0.374, respectively). However, endothelial function did not show any significant changes 2 h after eating a test meal in all groups. PHTG increases oxidant stress and further deteriorates endothelial function, even in patients with CAD. Both ACE-I and fibrates have an antioxidant effect but no acute beneficial effects in terms of endothelial function under conditions of PHTG in CAD patients.

Estimation of Nationwide Vaccination Coverage and Comparison of Interview and Telephone Survey Methodology for Estimating Vaccination Status

This study compared interview and telephone surveys to select the better method for regularly estimating nationwide vaccination coverage rates in Korea. Interview surveys using multi-stage cluster sampling and telephone surveys using stratified random sampling were conducted. Nationwide coverage rates were estimated in subjects with vaccination cards in the interview survey. The interview survey relative to the telephone survey showed a higher response rate, lower missing rate, higher validity and a less difference in vaccination coverage rates between card owners and non-owners. Primary vaccination coverage rate was greater than 90% except for the fourth dose of DTaP (diphtheria/tetanus/pertussis), the third dose of polio, and the third dose of Japanese B encephalitis (JBE). The DTaP4: Polio3: MMR1 fully vaccination rate was 62.0% and BCG1:HepB3:DTaP4:Polio3:MMR1 was 59.5%. For age-appropriate vaccination, the coverage rate was 50%-80%. We concluded that the interview survey was better than the telephone survey. These results can be applied to countries with incomplete registry and decreasing rates of landline telephone coverage due to increased cell phone usage and countries. Among mandatory vaccines, efforts to increase vaccination rate for the fourth dose of DTaP, the third dose of polio, JBE and regular vaccinations at recommended periods should be conducted in Korea.

The Stages of Physical Activity and Exercise Behavior: An Integrated Approach to the Theory of Planned Behavior

This research aims to verify whether it is possible to explain the health-promoting behaviors based on sociodemographic characteristics by integrating the theory of planned behavior (TPB) proposed by Ajzen in 1988 and the transtheoretical model (TTM) proposed by Prochaska and DiClemente in 1983. In particular, the aim was to verify whether the variables of the TPB can properly distinguish the stages of change in exercise in the proposed integrated model and to figure out how attitude, subjective norm, perceived behavior control, influence, and intention-can explain the stages of change in exercise. Investigators who have taken previous training for the survey visited and interviewed 3658 people older than 30 years in the chosen town by multistage sampling method from July 27 to July 31, 2003. After the exclusion of inappropriate data out of 760 participants, only data from 584 participants were used for this research. χ2 test, t test, and 1-way analysis of variance were used to identify the difference between the distribution of the stages of change in exercise and the variables of the means. A discriminant analysis to verify the accuracy of the stages of change in exercise by means of the variables of the TPB and a path analysis to verify the fit of the integrated model were also used. The variables of the TPB were useful to satisfactorily distinguish and predict the stages of change in exercise. But to clarify the validity of this model, more diversified research should be conducted in the future, and the results must be accumulated.

The immunogenicity of a single dose of hepatitis A virus vaccines (Havrix® and Epaxal®) in Korean young adults.

Purpose Assessing the immunogenicity of a single dose of hepatitis A virus (HAV) vaccines is important because some people receive only a single dose. However, previous studies have shown variable results and have not examined the effects of demographic characteristics other than gender. This study was performed to examine the immunogenicity of a single dose of HAV vaccine according to the vaccine type and demographic characteristics in young adults. Materials and Methods Seronegative medical school students were randomly allocated to receive either Havrix or Epaxal. Results After approximately 11 months, the seroconversion rate in 451 participants was 80.7%. In men, the Havrix group showed a significantly higher seroconversion rate (81.9%) than the Epaxal group (69.2%), whereas both vaccine groups showed similarly high immunogenicity in women (Havrix: 90.1%, Epaxal: 92.9%; P for interaction=0.062). According to the results of a multivariate analysis, Epaxal showed significantly lower immunogenicity than Havrix only in men. Age, obesity, drinking, smoking, and follow-up time did not significantly affect seroconversion in either gender. Conclusion The seroconversion rate of single-dose HAV vaccines was low in men, particularly in those who received Epaxal. Our results suggest that gender effects should be considered when comparing the immunogenicity of different HAV vaccines.

Handwashing with soap and national handwashing projects in Korea: focus on the National Handwashing Survey, 2006-2014.

OBJECTIVES: Handwashing is the most fundamental way to prevent the spread of infectious diseases. Correct handwashing can prevent 50 to 70% of water-infections and foodborne-infections. We report the results of a fact-finding study on general handwashing attitude and practice in the Republic of Korea by analyzing habits and awareness among adults and students (grades 4 to 12) based on the 2006 to 2014 National Handwashing Surveys and observational surveys. METHODS: The awareness survey was performed by telephone interviews with adults and students in 16 municipalities and provinces sampled by quota for region, sex and age. The observational survey was performed in subway, railway, and other public restrooms in seven municipalities selected through systematic sampling. RESULTS: Adults and students washed their hands with soap/sanitizer an average of 6.6 and 5.2 times daily, respectively, in 2014, an increase and decrease compared to 2006 (4.8) and 2013 (6.8). Their average daily handwashing frequency in 2014, 9.8 and 8.3, was higher than in 2006 (7.6), but lower than in 2013 (10.3).The percentage of participants handwashing with soap after using the restroom (29.5%) has been increasing since 2009, but remain slower than in other countries (42% to 49%). The percentages of participants handwashing with water in 2014, 2013, and 2011 were 57.5%, 72.6%, and 71.4%, respectively. CONCLUSIONS: Handwashing with soap is an important national public health issue, and national projects promoting it should be given high priority. Research support is necessary to provide scientific evidence of the importance of handwashing with soap and to develop and implement evidence-based policies.

The Level of Emotional Labor among Workers in One University Hospital

Purpose : The purpose of this study was to investigate the level of emotional labor and to identify affecting factors on emotional labor among one university hospital employees. Material and Method : This study was based on cross-sectional, self-administered, and Internet-based survey. The survey was conducted from Mar. 2 to Mar. 28. 2011. Total subjects were 812 employees working in one university hospital. Total response rate was 61.5%. Modified evaluation tool was used, which was originally developed by Morris and Feldman, to measure the level of emotional labor among hospital personnel. In order to identify the affecting factors on high level of emotional labor, we conducted logistic regression. The SPSS statistical software package was used to perform the statistical analysis. All statistical tests were 2-sided and a p-value

Positive Vascular Remodeling in Culprit Coronary Lesion is Associated With Plaque Composition: An Intravascular Ultrasound-Virtual Histology Study

Background and Objectives The relationship between the positive remodeling (PR) of a coronary artery and plaque composition has been studied only in a relatively small number of study population or non-culprit lesion. We evaluated the association between coronary plaque composition and coronary artery remodeling in a relatively large number of culprit lesions. Subjects and Methods The study population consisted of 325 consecutive patients with coronary artery disease that underwent intravascular ultrasound-virtual histology examination in a culprit lesion. The remodeling index (RI) was calculated as the lesion external elastic membrane (EEM) area divided by the average reference EEM area. Results The lesions with PR (RI>1.05, n=97, mean RI=1.19±0.12) had a higher fibrous volume/lesion length (3.85±2.12 mm3/mm vs. 3.04±1.79 mm3/mm, p=0.003) and necrotic core volume/lesion length (1.26±0.89 mm3/mm vs. 0.90±0.66 mm3/mm, p=0.001) than those with negative remodeling (NR) (RI<0.95, n=132, mean RI=0.82±0.09). At the minimal luminal area site, the lesions with PR had a higher fibrous area (5.81±3.17 mm2 vs. 3.61±2.30 mm2, p<0.001), dense calcified area (0.73±0.69 mm2 vs. 0.46±0.43 mm2, p=0.001), and necrotic core area (1.93±1.33 mm2 vs. 1.06±0.91 mm2, p<0.001) than those with NR. RI showed significant positive correlation with fibrous volume/lesion length (r=0.173, p=0.002), necrotic core volume/lesion length (r=0.188, p=0.001), fibrous area (r=0.347, p<0.001), fibrofatty area (r=0.111, p=0.036), dense calcified area (r=0.239, p<0.001), and necrotic core area (r=0.334, p<0.001). Multivariate analysis showed that the independent factor for PR was the necrotic core volume/lesion length (beta=0.130, 95% confidence interval; 0.002-0.056, p=0.037) over the entire lesion. Conclusion This study suggests that PR in a culprit lesion is associated with the necrotic core volume in the entire lesion, which is a characteristic of vulnerable plaque.

The Effect of Re-building of Public Health Facilities on the Hypertension Control in the Rural Area

Objectives: The purpose of this study was to determine the effect of public health facilities rebuilding on the hypertension control in the rural area. Method: 6 health centers and 59 health subcenters in some Chung-chung province was surveyed. And 29,503 patients were finally selected who had records of prescription about hypertension at list once in those health facilities from July 1th, 2005 to June 30th, 2006. Demographic variable of patients and whether medical doctor was a medical specialist or not, and whether the facilities were recently rebuilded or not was measured. Results: The Overall control rate was 53.9%. Women had higher hypertension control rate than men. And 60s and 70s years old are had higher hypertension control rate than 40s and 80s years old. Patients who had been treated from medical specialist had higher hypertension control rate than general doctor. And patient who treated in rebuilded public health facilities had higher hypertension control rate. Conclusions: Rebuilding of public health facilities were related to increasing control rate of hypertensive patients.

Seropositivity among Korean Young Adults Approximately 2 Years after a Single-Dose Vaccination against Hepatitis A Virus.

We previously observed 80.7% seropositivity and a significant interaction between gender and hepatitis A virus (HAV) vaccine type (Havrix vs. Epaxal) on the seropositivity approximately 11 months after single-dose HAV vaccinations in Korean young adults. Our objective was to evaluate seropositivity approximately 2 years after a single-dose HAV vaccination and the influence of demographic characteristics on seropositivity, including the interaction between gender and vaccine type. Seronegative medical school students were randomly vaccinated with Havrix or Epaxal. Based on a total serum anti-HAV antibody titer cutoff of 20 IU/mL, 338 participants (76.0%) of the 445 vaccinees were seropositive 20–25 months after a single-dose HAV vaccination. The seropositive rates were similar after vaccination with Havrix (77.0%) and Epaxal (74.9%). Univariate analysis indicated that female (p = 0.052) and less obese (p < 0.001) participants had a higher seropositive rate, whereas other characteristics such as age, alcohol use, smoking history, vaccine type, and follow-up duration were not associated with seropositivity. Multivariate analysis indicated that women (p = 0.026) and participants with moderate alcohol use (p < 0.001) showed significantly higher seropositive rates than men and participants with no or low alcohol use, respectively. The seropositive rates after vaccination with Havrix and Epaxal were 70.9% and 67.5% in men and 87.7% and 91.3% in women, respectively (p for interaction = 0.304). Compared with the seropositive rate approximately 11 months after vaccination, the seropositive rate decreased substantially only in men in the Havrix group (11.0% points), and consequently, the interaction between gender and vaccine type disappeared while seropositivity remained high (87.7% and 91.3% in Havrix and Epaxal groups, respectively) among women approximately 2 years after vaccination. Further studies are needed to assess whether the seropositive rate would be maintained in all groups more than 2 years after a single-dose HAV vaccination.