EMJ, A Research Platform for “Future Ready, Ewha Medicine” / 이화의대지

In 1978, the foundation year of The Ewha Medical Journal, Dean Kim Gu-ja first published the academic journal entitled ‘The Ewha Medical Journal (EMJ)’, which was our long-cherished wish. She emphasized the journal should be published by our hands and we must develop them by our own strength. For this purpose, she also highlighted that professors should constantly conduct research and provide generous support for the journal. Forty-four years later, we are planning to reorganize the EMJ in 2022. As the Dean of Ewha Womans University College of Medicine (Fig. 1), the first thing I would like to ask is “proactive contribution and participation of all professors and students” to continue the history and tradition of The Ewha Medical Journal. Through reorganization such as opening to other colleges and providing a reader-friendly environment, the EMJ can quickly share the latest knowledge of medicine and health science to the general public, students, and doctors. And our journal will play the role of a forum where ideas and information can be exchanged and academic discussions will be held among researchers in Ewha Womans University. In addition, various changes such as ‘Ewha Medical Education Center (EMEC)’ and ‘Ewha Medical Award’ made under the slogan of “Future Ready, Ewha Medicine” will be significant since they are resulted from medical education research to foster doctors/medical scientists in the era of the 4 th Industrial Revolution. I hope the EMJ will serve as a channel for the professors of our college to present their research results, discuss opinions, and disseminate medical information to the students, scientists and public. I also believe the journal will serve as the foundation for fostering future talents in convergence studies, which is urgently required for medical education. Marking its 45 th anniversary, The Ewha Medical Journal’s reorganization can be completed with proactive research and participation by all professors and students of Ewha Womans University. Thus, I would like to ask for your constant interest and support. Last but not least, I sincerely express my gratitude to all the editorial committee members including the editor-in-chief, Lee Ryung-Ah, for their hard work and efforts.

Cohort profile: the Ewha Birth and Growth Study / 한국역학회지

With the introduction of life-course epidemiology, researchers realized the importance of identifying risk factors in early life to prevent chronic diseases. This led to the establishment of the Ewha Birth and Growth Study in 2001; the study is a prospective birth cohort designed to provide evidence of early life risk factors for a child’s growth and health. Participants were recruited from those who visited Ewha Womans University Mokdong Hospital (a tertiary hospital in southwest Seoul, Korea) for prenatal care at 24-28 weeks of gestation. In total, 891 mothers enrolled in this study between 2001 and 2006 and their offspring (n=940) were followed-up. Regular check-up examinations of offspring were conducted at 3 years, 5 years, and 7 years of age and every year thereafter. To consider age-related health issues, extensive data were collected using questionnaires and measurements. In 2021, the study subjects will reach 19 years of age, and we are planning a check-up examination for early adulthood. About 20 years have passed since the cohort data were collected, and we have published results on childhood health outcomes associated with prenatal and birth characteristics, genetic and epigenetic characteristics related to childhood metabolism, the effects of exposure to endocrine disruptors, and dietary patterns in childhood. Recently, we started reporting on topics related to adolescent health. The findings will facilitate identification of early life risk factors for chronic diseases and the development of interventions for diseases later in life.

The Association of Ovarian Reserve with Exposure to Bisphenol A and Phthalate in Reproductive-aged Women

Background@#Exposure to endocrine disrupting chemicals (EDCs) that influence the hormonal and homeostatic systems is known to be associated with gynecologic health risks in many countries. In this study, we evaluated exposure to EDCs associated with diminished ovarian reserve (DOR) and gynecologic health risks. @*Methods@#This cross-sectional study was performed from September 2014 to November 2014 and included 307 Korean reproductive-aged women. Anthropometric measurements, laboratory tests with urine and blood sampling and pelvic ultrasound examinations were performed. @*Results@#Urinary bisphenol A (BLA) level was significantly higher in the DOR group with antiMüllerian hormone lower than 25 percentile (1.89 ± 2.17 ug/g and 1.58 ± 1.08 ug/g, P < 0.05).Urinary mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate and mono-N-butyl phthalate, and substrates of phthalate were evaluated and no significant difference was observed between the DOR group and non-DOR group. Logistic regression analysis suggested an increase in infertility in high BPA exposure group and the odds ratio (OR, 4.248) was statistically significant after adjustment for age, birth control pills, and the age of menarche, parity, and waist circumference. High phthalate exposure was associated with endometrial polyp after adjustment (OR, 2.742). @*Conclusion@#BPA exposure might be associated with DOR and infertility. Meanwhile, endometrial polyp is increased in women with high phthalate exposure. Therefore, the risk of exposures to EDCs for reproduction should be a matter of concern in reproductive-aged women.

Cohort profile: the Ewha Birth and Growth Study / 한국역학회지

With the introduction of life-course epidemiology, researchers realized the importance of identifying risk factors in early life to prevent chronic diseases. This led to the establishment of the Ewha Birth and Growth Study in 2001; the study is a prospective birth cohort designed to provide evidence of early life risk factors for a child’s growth and health. Participants were recruited from those who visited Ewha Womans University Mokdong Hospital (a tertiary hospital in southwest Seoul, Korea) for prenatal care at 24-28 weeks of gestation. In total, 891 mothers enrolled in this study between 2001 and 2006 and their offspring (n=940) were followed-up. Regular check-up examinations of offspring were conducted at 3 years, 5 years, and 7 years of age and every year thereafter. To consider age-related health issues, extensive data were collected using questionnaires and measurements. In 2021, the study subjects will reach 19 years of age, and we are planning a check-up examination for early adulthood. About 20 years have passed since the cohort data were collected, and we have published results on childhood health outcomes associated with prenatal and birth characteristics, genetic and epigenetic characteristics related to childhood metabolism, the effects of exposure to endocrine disruptors, and dietary patterns in childhood. Recently, we started reporting on topics related to adolescent health. The findings will facilitate identification of early life risk factors for chronic diseases and the development of interventions for diseases later in life.

Introduction of Community-Based Preconception Care for Men and Women of Childbearing Age in Seoul

Community-based preconception care for men and women of childbearing age has been introduced in Seoul. The program aims to focus on problem areas such as low birth rate, fertility issues potentially due to late marriages, preterm or premature births, and low-birthweight in newborn babies. The district administration officials of Seoul, as well as, academics from the Korean Society of Maternal and Child Health, developed a protocol by using a questionnaire and laboratory test for screening risk factors in pregnancy. The protocol was tested on a trial basis in four local districts in Seoul from July 2017 to 2018, extended to 12 local districts in 2019, and all 25 districts in Seoul in 2020. The protocol includes AntiMullerian Hormone tests to assess women’s ovarian reserve and male health checkups that include semen analysis and physical examinations of genitalia. These tests are conducted for early detection and treatment of infertility, especially in cases of late marriages. In order to prevent women being abandoned during pregnancy (leading them to single-parenting), the protocol also emphasizes building a gender-sen sitive environment by encouraging more male participation. A monitoring group comprised of Seoul city district officials and academics from the Korean Society of Maternal and Child Health, regularly visited the local districts to observe improvements and keep the program officials up to date. In addition, the group also conducted a mobile phone survey for feedback on the program. The interest and support of the resi dents in Seoul city, and positive results and development in pregnancy care and childbirth, are needed to stabilize and extend this protocol.

The Association between Land Use Rate and Low Birth Weight Rate in Seoul: Ecological Study

PURPOSE: This paper is based on an ecological study. From 2008 to 2014, we identified the differences in the Low Birth Weight (LBW) rate according to land use rate among the 25 autonomous regions of Seoul. We also demonstrated the effects of ecological environmental differences on maternal outcomes. METHODS: The National Statistical Office obtained data of residential areas and rates, commercial areas and rates, industrial areas and rates, green areas and rates of the 25 autonomous regions from 2008 to 2014. It also obtained data regarding low birth weight rates for the same region and period. The rate of land use is divided into four stages by residential rate, three by commercial rate, three by industrial rate, and four by green area rate The higher the step, the higher the rate is. The method by Baron and Kenny was used to investigate the mediating effects of the concentration of air pollutants (PM10, PM2.5, SO2, NO2, O3, CO) on LBW and its relationship to land use in each district of Seoul. The relationship between the change of land use and LBW rate in each region was analyzed with general regression analysis and cluster analysis. RESULTS: This study shows that as the rate of green area to overall area increases in Seoul's industrial area, a causal effect is observed with low birth weight, mediated by SO2. Regression analysis revealed that LBW rates were significantly higher in heavily industrial areas (beta=1.27, SE=0.27, p<0.05), while LBW rate was significantly lower in considerably greener areas (beta=−2.21, SE=0.39, p<0.05). CONCLUSION: We confirmed differences in the relationship between residential, commercial, industrial, and green areas, air pollutants, and LBW rate. Areas with high industrial rates have a high LBW rate, while areas with high green rates have a low LBW rate. The autonomous land use ratio includes direct environmental factors. Therefore, pregnant women who are living in highly industrial areas should be especially careful to manage their living environment.

Survey on Awareness for Environmental Health Risk of Fetus and Infant in Reproductive-aged Women / 이화의대지

OBJECTIVES: The accumulated evidence shows that adult disease may have origins during the fetal period and maternal environmental exposure may affect fetus and infant health. To assess the environmental health of fetus and infants and examine women's concerns about environmental health, we designed and conducted an environmental health survey in reproductive-aged women in 2011. METHODS: A stratified multi-stage design was adopted for our survey, and 1,000 reproductive-aged women aged 25 to 39 years participated. The participants were asked to complete an electronic questionnaire using the computer-assisted web interviewing method. All the participants were married woman, and 80% had experienced pregnancy before completing the survey. RESULTS: In the study, 86.3% of the participants responded that they are worried about the environmental problems that may affect the fetus and infant. The participants responded that they were most worried about global warming and climate change (36.2%), electromagnetic waves (31.4%), and endocrine disrupting chemicals (25.1%). Moreover, participants responded that environmental problem can cause children's allergic disease, such as atopic dermatitis, metabolic syndrome and growth development. CONCLUSION: We found reproductive-aged women have high awareness of children's environmental health. We also recommended that additional surveys on mother and child environmental health be conducted to make a health policy for women, fetus and infant.

Association between cadmium and anti-Mullerian hormone in premenopausal women at particular ages

BACKGROUND: Anti-Mullerian hormone (AMH) in women is secreted by granulosa cells of antral follicles. AMH appears to be a very stable marker for ovarian function. It may be used to diagnosis cases of premature ovarian failure, polycystic ovary syndrome (PCOS), and ovarian tumors. It has been suggested that cadmium exposure can reduce female fecundity. The purpose of this study was to investigate whether environmental exposure to cadmium was associated with alterations in AMH with regards to age. METHODS: In a cross-sectional study, the data of premenopausal women living in Seoul, ranging from 30 to 45 of age was collected. The study included a total of 283 women who completed serum AMH and whole blood cadmium assessments. Linear regression analyses were used in order to examine the association between cadmium and AMH. Given that age was the strongest confounder in both cadmium and AMH concentrations, we stratified subjects by 5 years old and analyzed their data. RESULTS: Geometric mean concentrations of blood cadmium and AMH were 0.97 μg/L and 3.02 ng/ml, respectively. Total association between cadmium and AMH was statistically significant (adjusted coefficient = − 0.34 (0.15), p = 0.02). After stratification, the only age group with a negative association between cadmium and AMH were the women raging between 30 and 35 years (adjusted coefficient = − 0.43 (0.18), p = 0.01). CONCLUSIONS: The results of this study suggest that environmental exposure to cadmium may alter the AMH level of premenopausal women, depending on their age group.

Gender-based Comparison of Knowledge on Preconception Care

BACKGROUND: There have been many voices highlighting the necessity of preconception care as a preventive approach to achieve better pregnancy outcomes for health promotion of mothers and babies. It is important to get preconception care for both men and women, as they play equally important roles for healthy pregnancy. Also, awareness and knowledge of men and women about their health are important factors for behavioral changes for preconception care. PURPOSE: The purpose of this study is to analyze the level of awareness about men and women's preconception care and knowledge of the determinants of healthy pregnancy by gender. Our second goal was to compare men and women's level of awareness and knowledge on it. METHODS: The participants were 500 males and females (aged over 19 years and under 49 years old) either living or working in Seoul city. The data collection period of the study was from July to December, 2017. An online survey was conducted using a panel of online vendors. Then the collected data were analyzed using SPSS 24.0. RESULTS: Awareness about both men and women's preconception care was significantly higher in women than in men (p=0.004, p=0.002). Furthermore, there was a significant difference between men and women (p=0.00) in the total score of knowledge on the determinants of preconception care, including smoking, alcohol drinking, age, folic acid intake, and check-up for infectious disease (p=0.00; means women 8.20±1.95 and men 7.27±2.38). Significant gender differences were also found on some items, such as men's alcohol drinking, men's age, men's check-up for infectious disease, women's intake of folic acid, women's check-up for infectious disease. The level of knowledge on men's folic acid intake was the lowest in both men and women. CONCLUSION: Based on the results on the analysis of gender differences in the awareness and knowledge about preconception care, it is necessary to develop and implement preconception care programs based on the gender perspective approach to make women and men equally share responsibility of the birth result.

Systematic Review of Heavy Metal Concentrations in Fish and Shellfish in Korea / 이화의대지

OBJECTIVES: Heavy metals ingested through the consumption of aquatic products can accumulate in the human body over the long-term and cause various health problems. This study aims to present comprehensive data on the amount of heavy metals found in fish and shellfish in Korea using a systematic review of studies that report on that issue. METHODS: The study used the following databases: PubMed, Korean Studies Information Service System, and Research Information Sharing Service. The search terms for PubMed included fish OR shellfish OR seafood AND mercury OR cadmium OR lead OR heavy metal AND Korea. The search terms for Korean Studies Information Service System and Research Information Sharing Service included eoryu sueun, eoryu kadeumyum, eoryu nab, eoryu jung-geumsog, paeryu sueun, paeryu kadeumyum, paeryu nab, paeryu jung-geumsog, eopaeryu sueun, eopaeryu kadeumyum, eopaeryu nab, and eopaeryu jung-geumsog. RESULTS: A total of 32 articles were selected for review. The total mercury, lead, and cadmium concentrations in fish and shellfish reported in each of the articles are summarized, as are the species of fish and shellfish with relatively high concentrations of heavy metals. Total mercury concentrations tended to be higher in predatory fish species, such as sharks, billfishes, and tuna, while lead and cadmium concentrations tended to be higher in shellfish. CONCLUSION: This paper is the first to report a comprehensive summary of the concentrations of heavy metals in fish and shellfish. This data could be used as evidence to protect Koreans from exposure to heavy metals due to the consumption of highly polluted aquatic products.

Parkinson's Disease among Firefighters : A Focused Review on the Potential Effects of Exposure to Toxic Chemicals at the Fire Scene

Previous studies have found that firefighters have a tenfold higher prevalence of Parkinson's disease (PD) compare to the general population. Firefighters are constantly exposed to various occupational hazards including toxic chemicals of fire residue and the toxic chemicals can effects development and progression of PD. Nevertheless, there were no studies about the association between exposure to chemical byproducts of combustion and the development of PD among firefighters. Thus the aim of this study is to look into existing researches regarding the effect of chemical byproducts of combustion on the development of PD. An extensive literature search was conducted to identify harmful chemical components of smoke and fire residue, using the PubMed database during November of 2016. We searched for relevant articles by combining several keywords that contained “Parkinson's disease” and each of the different toxic chemicals, yielding a total of 1401 articles. After applying the selection criteria, 12 articles were chosen. Chemical substances reported to have a harmful effect on PD, in at least one article, were carbon monoxide, toluene, manganese and lead. Carbon monoxide and metal substances including manganese and lead were found to be associated with an increased PD risk in more than two articles. There was a heightened risk of PD in firefighters due to exposure of chemical byproducts of combustion including carbon monoxide, toluene, man-ganese and lead. However, to the best of our knowledge, to support this result we need more systematic epidemiological studies about these risk factors of PD among firefighters. In addition, further studies for the effects of prolonged exposure to toxic fire residue on the development and progression of PD in firefighters are needed.

hMSCs suppress neutrophil-dominant airway inflammation in a murine model of asthma

Although chronic eosinophilic inflammation is a common feature in patients with asthma, some patients have neutrophil-dominant inflammation, which is known to be associated with severe asthma.Human mesenchymal stem cells (hMSCs) have shown promise in treating various refractory immunological diseases. Thus, hMSCs may represent an alternative therapeutic option for asthma patients with neutrophil-dominant inflammation, in whom current treatments are ineffective. BALB/c mice exposed to ovalbumin and polyinosinic:polycytidylic acid (Poly I:C) to induce neutrophilic airway inflammation were systemically treated with hMSCs to examine whether the hMSCs can modulate neutrophilic airway inflammation. In addition, cytokine production was evaluated in co-cultures of hMSCs with either anti-CD3/CD28-stimulated peripheral blood mononuclear cells (PBMCs) obtained from asthmatic patients or cells of the human bronchial epithelial cell line BEAS-2B to assess the response to hMSC treatment. The total number of immune cells in bronchoalveolar lavage fluid (BALF) showed a dramatic decrease in hMSC-treated asthmatic mice, and, in particular, neutrophilic infiltration was significantly attenuated. This phenomenon was accompanied by reduced CXCL15 production in the BALF. BEAS-2B cells co-cultured with hMSCs showed reduced secretion of IL-8. Moreover, decreased secretion of IL-4, IL-13 and IFN-γ was observed when human PBMCs were cultured with hMSCs, whereas IL-10 production was greatly enhanced. Our data imply that hMSCs may have a role in reducing neutrophilic airway inflammation by downregulating neutrophil chemokine production and modulating T-cell responses.

Blood cadmium and volume of uterine fibroids in premenopausal women

BACKGROUND: A number of studies have found associations between heavy metals and uterine fibroids, but the results are inconsistent. Here, we conducted this research to demonstrate the relationships between blood heavy metal concentrations and uterine fibroid volume as well as the rate of uterine fibroid presence. METHODS: In a cross-sectional study, we collected data from 308 premenopausal women aged 30–49 years in Seoul; uterine fibroids are ascertained by past history of myomectomy and pelvic ultrasonography. In the analytic phase, we first analyzed the presence of the fibroids and the concentrations of heavy metals via logistic regression. In subgroup analysis, we used simple and multiple linear regression analyses to examine the associations between heavy metals and uterine fibroid volume. RESULTS: There was no connection between the heavy metal concentrations and the presence of uterine fibroids, but the odds of women having fibroids were higher with three particular metals. In subgroup analysis, the association between blood cadmium concentrations and uterine fibroid volume was statistically significant (adjusted beta coefficient = 2.22, 95% confidential interval: 0.06–4.37). In contrast, blood mercury and lead concentrations were not significantly associated with uterine fibroid volume. CONCLUSIONS: Our findings are the first that we know to report the association of blood cadmium concentrations with the volume of uterine fibroids. We expect that our findings will be used as evidence for supporting policies to improve premenopausal Korean women's health.

Combined effect of folate and adiposity on homocysteine in children at three years of age

BACKGROUND/OBJECTIVES: Cardiovascular diseases is a major cause of death and is responsible for 23.8% of deaths in Korea. Clinical symptoms manifest in adulthood, but susceptibility begins in utero. Elevated homocysteine levels and adiposity might be linked to a greater risk in children as well as adults. We hypothesized that those who have simultaneous risk for folate and adiposity would be affected with elevated homocysteine levels at 3 years of age. SUBJECTS/METHODS: From the ongoing birth cohort at Ewha Womans University Mok-Dong Hospital, we compared adiposity parameters, serum homocysteine, and folate levels in 238 children (118 boys and 120 girls) at three years of age. The relationship between birth outcome, current weight and body mass index (BMI), postnatal growth, and homocysteine level were assessed using correlation and general linear model. Additionally, we assessed the combined effect between blood folate status and adiposity on current homocysteine levels. RESULTS: Birth characteristics were not correlated with homocysteine. Current weight, BMI, upper-arm circumference, skinfold thickness, waist circumference, and hip circumference were positively correlated with homocysteine at three years of age (P < 0.05). Folate level was negatively correlated with homocysteine at three years of age (P < 0.0001). A relative high anthropometric measure which is compatible with adiposity and low folate level was associated with high homocysteine levels. CONCLUSION: We found a combined effect of adiposity and folate levels with homocysteine levels at three years of age. This implicates the beneficial role of folate supplementation in the high-risk population at an early age.

Long working hours and overweight and obesity in working adults

BACKGROUND: Previous studies have identified a link between gender and the various risk factors associated with obesity. We examined obesity risk factors in working adults to identify the effects of differences in body mass index (BMI) and percentage body fat (PBF) between women and men. METHODS: A total of 1,120 adults agreed to participate in the study. Data from 711 participants, including 411 women and 300 men, were analyzed. Multiple logistic regression analysis was used to estimate the effects of risk factors on obesity and being overweight. In addition, the least-squares (LS) means of both BMI and PBF were estimated by analysis of covariance (ANCOVA) in a generalized linear model.  RESULTS: Increases in BMI and PBF were significantly related to an age > 50 years and long working hours in women after compensating for confounding factors. Using the PBF criterion, the odds ratio (OR) of being overweight or obese in women > 50 years of age who worked for > 9 h a day was 3.9 (95% confidence interval [CI], 1.05–11.00). For BMI, women who were > 50 years of age and worked for > 9 h a day were 3.82 times (95% CI, 1.31–11.14) more likely to be overweight or obese than those who were 50 years of age and long working hours in women. Further studies are needed to investigate the underlying mechanisms of this relationship and its potential implications for the prevention and management of excess weight and obesity.

Effect of maternal job strain during pregnancy on infant neurodevelopment by gender at 6 and 12 months: Mothers and Children's Environmental Health (MOCEH) study

OBJECTIVES: Limited evidence is available regarding the association between prenatal job strain and infant neurodevelopment. Most studies used stress indicators other than job strain to explain the relationship between prenatal maternal stress and child development. The objective of this study was to investigate the association between maternal job strain during pregnancy and neurodevelopment in infancy. METHODS: Mothers and Children's Environmental Health (MOCEH) study, an on-going prospective birth cohort study, has been conducted in South Korea since 2006. Job strain during pregnancy was measured using Korean version of Job Content Questionnaire (JCQ). Infant neurodevelopment was assessed using Korean Bayley Scale of Infant Development II (K-BSID-II) at 6 and 12 months of age. A total of 343 mother-child pairs that completed JCQ and K-BSID-II more than once were included. Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) defined in the K-BSID-II were used as outcome variables. RESULTS: Compared to infants from mothers with low job strain, significant (p < 0.05) decreases in PDI were found in infants from mothers with active and passive job at 6 months of age. After stratification by infant sex, boys in the high strain group had a lower MDI score than boys in the low job strain group at 12 months. On the other hand, girls in the high strain and active groups had higher MDI scores than girls in the low job strain group at 12 months. PDI at 12 months also showed different results by sex. Boys in the high strain and passive job groups had lower PDI scores than boys in the low job strain group. However, such difference was not observed in girls. CONCLUSIONS: The findings of this study suggest that prenatal job strain affects infant neurodevelopment in a gender-dependent manner.

Urinary nephrin: A new predictive marker for pregnancies with preeclampsia and small-for-gestational age infants

OBJECTIVE: The objective of this study was to determine the differences in urinary nephrin among controls, gravidas with preeclampsia (PE), and small-for-gestational age (SGA) infants. We also determined whether or not maternal urinary concentrations of nephrin are associated with the subsequent development of PE and SGA infants. METHODS: We analyzed maternal urinary levels of nephrin in women who were normal controls (n=50), women who were delivered SGA infants (n=40), and gravidas with PE (n=33) in the first, second and third trimesters. Urinary nephrin concentrations were measured with nephrin enzyme-linked immunosorbent assay kits. RESULTS: The levels of urinary nephrin were higher in gravida developing preeclampsia or SGA than in controls after adjusting serum creatinine (P<0.05 for both). Maternal urine concentrations of nephrin were higher in pregnancies complicated by SGA and PE in the third trimester (P<0.05), and also higher in pregnancies complicated by SGA in the first trimester (P<0.05). The sensitivity and specificity of nephrin in predicting SGA from normal pregnancies were 67% and 89% in the first trimester, 60% and 79% in the second trimester, and 80% and 84% in the third trimester, respectively. The sensitivity and specificity of nephrin in predicting PE from normal pregnancies were 67% and 83% in the first trimester and 73% and 79% in the third trimester, respectively. CONCLUSION: We suggest that urinary nephrin can be used as an early marker in pregnancies at risk for developing PE and SGA infants.

Relationship between Work Hours and Smoking Behaviors in Korean Male Wage Workers

OBJECTIVES: The purposes of this study are 1) to measure the prevalence of smoking according to weekly work hours by using data from the Korean Labor and Income Panel Study (KLIPS), and 2) to explain the cause of high smoking prevalence among those with short or long work hours by relative explanatory fraction. METHODS: Data from a total of 2,044 male subjects who responded to the questionnaire in the 10th year (2007) and 11th year (2008) of the Korean Labor and Income Panel Study were used for analysis. Current smoking, smoking cessation, continuous smoking, start of smoking, weekly work hours, occupational characteristics, sociodemographic and work-related factors, and health behavior-related variables were analyzed. Log-binomial regression analysis was used to study the relationship between weekly work hours and smoking behaviors in terms of the prevalence ratio. RESULTS: The 2008 age-adjusted smoking prevalence was 64.9% in the short work hours group, 54.7% in the reference work hours group, and 60.6% in the long work hours group. The smoking prevalence of the short work hours group was 1.39 times higher than that of the reference work hours group (95% confidence interval of 1.17-1.65), and this was explained by demographic variables and occupational characteristics. The smoking prevalence of the long work hours group was 1.11 times higher than that of the reference work hours group when the age was standardized (95% confidence interval of 1.03-1.19). This was explained by demographic variables. No independent effects of short or long work hours were found when the variables were adjusted. CONCLUSION: Any intervention program to decrease the smoking prevalence in the short work hours group must take into account employment type, job satisfaction, and work-related factors.

Cord Blood Soluble fms-Like Tyrosine Kinase 1 and Placental Growth Factor in Preterm Infants with Maternal Preeclampsia / 이화의대지

OBJECTIVES: The purpose of this study was to investigate the relationship of cord blood levels of soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF), and vascular endothelial growth factor (VEGF) in preterm infants with maternal preeclampsia. METHODS: Thirty six preterm infants born at Ewha Womans University Mokdong Hospital from January 2006 to August 2006 were studied after prior parental consent at mid-pregnancy. sFlt-1, PlGF, and VEGF levels in the cord blood of preterm neonate, with or without maternal preeclampsia, were measured using enzyme-linked immunosorbent assay. RESULTS: There was no difference in sFlt-1 between infants with and without maternal preeclampsia. Infants with maternal preeclampsia had significantly lower PlGF levels (P=0.035) and higher sFlt-1/PlGF ratio (P=0.080) with borderline significance. Cord blood VEGF levels were not related to maternal preeclampsia. Infants with maternal preeclampsia had lower birth weight (P=0.030), lower neonatal platelet count without statistical significance (P=0.064) and more likely to be small for gestational age (P=0.057). Neonatal platelet count was significantly correlated with cord blood PlGF levels (r=0.674, P=0.032). CONCLUSION: Increased sFlt-1/PlGF ratio and decreased PlGF may not only be related to the pathophysiology of maternal preeclampsia but also affect the neonatal platelet count and birth weight.

Association between Prenatal Exposure to Cadmium and Atopic Dermatitis in Infancy

Our objective was to evaluate the relationship between intrauterine exposure to cadmium and the presence of atopic dermatitis in infants 6 months of age, adjusted for covariates including exposure to other heavy metals. The present research is a component of the Mothers' and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project conducted in Korea. Study subjects were restricted to pregnant women in whom cadmium and lead levels were measured at delivery and whose infants were assessed for the presence of atopic disease at 6 months of age. The odds ratio (OR) for the presence of atopic dermatitis in 6-month-old infants whose cord blood had elevated cadmium levels, after adjustment for other covariates, was 2.350 (95% CI, 1.126-4.906). The OR for the presence of atopic dermatitis in infants whose cord blood had elevated lead levels was not significant. In the present study, the cord blood cadmium level was significantly associated with the presence of atopic dermatitis in 6-month-old infants; this was not true of the cord blood lead level. To the best of our knowledge, this is the first prospective study to show a relationship between prenatal exposure to cadmium and atopic dermatitis in infancy.