• Journal of Preventive Medicine and Public Health
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• v.33 no.2
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• pp.199-207
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• 2000

Objectives : This study was peformed to identify the risk factors related to the development of hypertension in a rural area. Method : Total of 3,573 subjects in Chung-Song County were interviewed and examined in 1996. The study cohort comprised 2,580 hypertension-free subjects aged above 20. One-year follow up was completed for 1,781 subjects(69.0%) in 1997. General characteristics(age, gender, education level, economic status, marital status), the family history of hypertension, diet, alcohol, smoking, coffee, stress, past history of oral contraceptive and menopausal status in female, height, weight, waist and hip circumference, baseline blood pressure, and serum total cholesterol were considered as risk factors. Results : Multivariate analysis using logistic regression model indicated that age(RH=1.50, 95% CI; 1.15-1.96), the family history of hypertension(RR=2.11, 95% CI; 1.04-4.26), waist-hip ratio(WHR) (RR=2.09, 95%, CI; 1.15-3.79), and baseline systolic blood pressure(130-139/<120mmHg)(RR=3.34, 95% CI; 1.47-7.60) were significant risk factors associated with the development of hypertension above the borderline level in male. In female, age(RR=1.06, 95% CI; 1.03-1.09), change in menopausal status$(no{\rightarrow}yes/no{\rightarrow}no)$ (RR=3.32, 95% CI; 1.01-10.87), baseline systolic blood pressure(120-129/<120mmHg: RR=2.00, 95% CI; 1.02-3.90)(130-139/<120mmHg: RR=2.64, 95% CI; 1.34-5.20) and baseline diastolic blood pressure(85-89/<80mmHg)(RR=4.09, 95% CI; 1.86-8.96) were identified as risk factors. Conclusions : Age and high normal blood pressure were significant risk factors for the development of hypertension above the borderline level. In addition, the family history of hypertension and WHR in men, and the change of menopausal status in women might be significant risk factors in Korea.

• Journal of Preventive Medicine and Public Health
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• v.33 no.2
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• pp.208-214
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• 2000

Objectives : Face-to-face interviews were conducted to investigate the relationship between blood pressure and the impairment of cognitive function in rural elderly (N=932) aged 60-64 in Dalsung County, April to September in 1996 Methods : Impairment of cognitive function was defined as a score of less than 23 by the Korean version of the Mini-Mental State Examination (MMSEK). Blood pressure was measured once in each subject using a portable automatic sphygmomanometer. Results : By univariate logistic regression on males, no category of systolic blood pressure bore statistical significance. Groups with diastolic blood pressures of, less than 80 mmHg, 90-94 mmHg, and more than 95mmHg had odds ratios of more than one compared with the reference group (80-89 mmHg). This was most significant in the group with blood pressures lower than 80 mmHg, which had a statistically significant odds ratio of 1.68 (95% confidence interval CI; 1.02-2.75). No category of blood pressure was statistically significant in females. Multivariate logistic regression for males, with adjustment for age, educational attainment, smoking, alcoholic drinking, body mass index, atherosclerotic disease, and antihypertensive medication use, did not alter the odds ratios significantly in terms of systolic blood pressure. However, the group with diastolic blood pressure of less than 80 mmHg had an increased odds ratio of 2.01 (95% CI; 1.15-3.52) compared with the reference group. In females, systolic blood pressure did not alter the odds ratio, but the group with a diastolic blood pressure of less than 80 mmHg had a statistically significant odds ratio of 0.57 (95% CI; 0.37-0.89). Conclusions : These results suggest that the relationship between blood pressure and cognitive function status is stronger diastolic than systolic blood pressure and that there is a complex relationship between blood pressure and cognitive function by sex.

• Journal of Preventive Medicine and Public Health
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• v.36 no.2
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• pp.137-146
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• 2003

Objectives : Impaired hearing is a prevalent occupational hazard, not only in industry, but also in the armed forces. In military life, noise has unusual characteristics, and constitutes a serious hazard to hearing. The aim of this study was to analyze the hearing threshold data in order to compare the hearing loss among shipyard workers, representing different workers, and a military service background. Methods : A cross-sectional audiological survey, combined with a questionnaire study, was conducted on a stratified random sample of 440 shipyard workers, with long-term exposure to noise. The employees were divided into four groups, according to their working and military service backgrounds, in relation to their exposure to noise. Results : As expected, the working and military noise exposure group (Group I) had significantly poorer hearing than the other groups. The high frequencies (2-8 kHz) showed the greatest difference in terms of poorer fearing in both ears. The prevalence of noise-induced hearing loss (NIHL) was highest in Group I. A logistic regression analysis was applied to determine the dependence of the NIHL in relation to age, smoking, drinking, working duration, ear protection, past history of ear diseases, and working and military sonics backgrounds, on the noise exposure The important factors found to be related to the NIHL, in relation to noise exposure were: age, work duration, and working and military service backgrounds. The adjusted odds ratio estimates for NIML in the right ear were 4.5 times greater (95% CI 1.7-11.6) for the military noise exposed group, and 7.9 times greater (95% CI 2.0-31.3) for the working noise exposed group than in the controls. The hearing thresholds at the pure-tone average and 4 kHz were significantly increased with age and work duration with both the working and military service backgrounds. Conclusions : From these results, specific preventive programs were planned, which should be assessed by epidemiological surveillance of the military noise exposed population.

• Journal of Preventive Medicine and Public Health
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• v.37 no.4
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• pp.329-336
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• 2004

Objectives : Iron (Fe) is an essential element in biological processes; however excessive Fe is harmful to human health. Some air pollutants contain a high level of Fe, and the human lung could therefore be over-exposed to Fe through inhaled air pollutants. This study was performed to investigate the role of metal transporters (divalent metal transporter 1, DMT1, and metal transporter protein 1, MTP1) in the lung under the environments of Fe deficiency in the body and Fe over-exposure in the lung. Methods : Rats were fed Fe deficient (FeD, 2-6 mg Fe/kg) or Fe supplemented (FeS, 120 mg Fe/kg) diet for 4 weeks, followed by a single intratracheal instillation of ferrous sulfate at low (10 mg/kg) or high (20 mg/kg) dose. Fe concentration was analyzed in the serum, lung and liver, and histopathological findings were observed in the lung at 24 hours after Fe administration. The level of DMT1 and MTP1 expression in the lung was analyzed by RT-PCR. Also, the effect of Fe deficiency in the body was evaluated on the level of Fe concentration and metal transporters compared to FeS-diet fed rats at the end of 4-week FeD or FeS diet. Results : The 4-week FeD diet in rats induced an Fe deficiency anemia with decreased serum total Fe, increased unsaturated Fe binding capacity and hypochromic microcytic red blood cells. The concentration of Fe in the lung and liver was lower in the FeD-diet fed rats than in the FeS-diet fed rats. The level of metal transporters mRNA expression was higher in the FeD-diet fed rats than in the FeS-diet. The concentration of Fe in the lung was increased in a dose-dependent pattern after intratracheal instillation of Fe into the rats, while the level of Fe in the serum and liver was not increased in the low-dose Fe administered rats. Therefore, DMT1 and MTP1 mRNA was highly expressed in both FeD-diet and FeS-diet fed rats, after intratracheal instillation of Fe. Conclusions : DMT1 and MTP1 mRNA were more highly expressed in FeD-diet fed rats than in FeS-diet fed rats. The over-exposure of Fe intratracheally induced high expression of metal transporters and increased Fe deposition in the lung in both FeD-diet and FeS-diet fed rats, but did not increase the Fe level of the serum and liver in low-dose Fe administered rats. These results suggest that the role of metal transporters in the lung might be different in a part from the duodenum under the environment of over-exposure to Fe.

• Journal of Preventive Medicine and Public Health
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• v.36 no.2
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• pp.93-100
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• 2003

Objectives : Because shipyard workers are involved with various manufacturing process, they are exposed to many kinds of hazardous materials. Welders especially, are exposed to bisphenol-A (BPA) during the welding and flame cutting of coated steel, This study was conducted to assess the exposure status of the endocrine disrupter based on the job-exposure matrix. The effects of the genetic polymorphism of xenobiotic enzyme metabolisms involved in the metabolism of BPA on the levels of urinary metabolite were investigated. Methods : The study population was recruited from a shipyard company in the f province. A total of 84 shipbuilding workers 47 and 37 in the exposed and control groups, respectively, were recruited for this study. The questionnaire variables included, age, sex, use of personal protective equipment, smoking, drinking and work duration. The urinary metabolite was collected in the afternoon and correction made for the urinary creatinine concentration. The of the CYP1A1, CYP2E1 and UGT1A6 genotypes were investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods with the DNA extracted from venous blood. Results : The urinary BPA level in the welders group was significantly higher than in the control group (p<0.05). The urinary BPA concentration with the wild type UGT1A6 was higher than the other UGT1A6 genotypes, but with no statistical significant. From themultiple regression analysis of the urinary BPA, the regression coefficient for job grade was statistically significant (p<0.05). Conclusions : The grade of exposure to BPA affected the urinary BPA concentration was statistically significant. However, the genetic polymorphisms of xenobiotics enzyme metabolism were not statistically significant. Further investigation of the genetic polymorphisms with a larger sample size is needed.

• Journal of Preventive Medicine and Public Health
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• v.40 no.5
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• pp.363-370
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• 2007

Objectives: The principal objective of this study was to determine the relationship between maternal exposure to air pollution and low birth weight and to propose a possible environmental health surveillance system for low birth weight. Methods: We acquired air monitoring data for Seoul from the Ministry of Environment, the meteorological data from the Korean Meteorological Administration, the exposure assessments from the National Institute of Environmental Research, and the birth data from the Korean National Statistical Office between January 1, 2002 and December 31, 2003. The final birth data were limited to singletons within $37{\sim}44$ weeks of gestational age. We defined the Low Birth Weight (LBW) group as infants with birth weights of less than 2500g and calculated the annual LBW rate by district. The air monitoring data were measured for $CO,\;SO_2,\;NO_2,\;and\;PM_{10}$ concentrations at 27 monitoring stations in Seoul. We utilized two models to evaluate the effects of air pollution on low birth weight: the first was the relationship between the annual concentration of air pollution and low birth weight (LBW) by individual and district, and the second involved a GIS exposure model constructed by Arc View 3.1. Results: LBW risk (by Gu, or district) was significantly increased to $1.113(95%\;CI=1.111{\sim}1.116)\;for\;CO,\;1.004(95%\;CI=1.003{\sim}1.005)\;for\;NO_2,\;1.202(95%\;CI=1.199{\sim}1.206\;for\;SO_2,\;and\;1.077(95%\;CI=1.075{\sim}1.078)\;\;for\;PM_{10}$ with each interquartile range change. Personal LBW risk was significantly increased to $1.081(95%\;CI=1.002{\sim}1.166)\;for\;CO,\;1.145(95%\;CI=1.036{\sim}1.267)\;for\;SO_2,\;and\;1.053(95%\;CI=1.002{\sim}1.108)\;for\;PM_{10}$ with each interquartile range change. Personal LBW risk was increased to $1.003(95%\;CI=0.954{\sim}1.055)\;for\;NO_2$, but this was not statistically significant. The air pollution concentrations predicted by GIS positively correlated with the numbers of low birth weights, particularly in highly polluted regions. Conclusions: Environmental health surveillance is a systemic, ongoing collection effort including the analysis of data correlated with environmentally-associated diseases and exposures. In addition. environmental health surveillance allows for a timely dissemination of information to those who require that information in order to take effective action. GIS modeling is crucially important for this purpose, and thus we attempted to develop a GIS-based environmental surveillance system for low birth weight.

• Childhood Kidney Diseases
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• v.16 no.2
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• pp.73-79
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• 2012

Purpose: The association of mitochondrial DNA (mtDNA) mutations, deletions and copy number with progressive changes in patients with some glomerular disease and end-stage renal disease have been reported. In this study, we performed mtDNA mutation analysis in children with IgA nephropathy to investigate its role in progressive clinical course. Methods: Seven children with IgA nephropathy were involved in this study. MtDNA isolated from platelet was amplified by PCR and sequenced entirely. Results: The mean age at renal biopsy was $11.5{\pm}2.2$ year and the mean age at latest evaluation was $17.9{\pm}3.2$ year. The mean follow-up period were $7.8{\pm}3.1$ years. Patients was divided into 2 groups according to the amount of proteinuria at presenting manifestation. Group 2 patients were nephrotic syndrome. Renal function reveals within normal range in all patients. In group 2 patients, the mean serum albumin level was significantly lower than those of group 1 ($3.7{\pm}0.6g/dL$ vs. $4.7{\pm}0.2g/dL$, P=0.0241) and the mean total cholesterol level was significantly higher than those of group 1 ($222.7{\pm}35.7mg/dL$ vs. $148.3{\pm}29.1mg/dL$, P=0.0283). In Group 2 patients, total amount of protein of 24 hour collected urine also significantly higher than those of group 1 ($1,466.0{\pm}742.5mg$ vs. $122.5{\pm}48.1mg$, P=0.0135). Pr/Cr ratio in random urine sample was also higher in group 2 than those of group 1 but the statistical significance was not noted ($1.8{\pm}1.6$ vs. $0.2{\pm}0.2$, P=0.0961). Deletion of mtDNA nt 8272-8281 were observed in two patients, one patient in each groups, respectively. This is noncoding lesion. No patients demonstrated the mtDNA mutations. Conclusions: We have identified a deletion of mtDNA nt 8272-8281 in two children with IgA nephropathy. Further studies are needed to clarify the role of mitochondrial function in the progressive change of IgA nephropathy.

• Childhood Kidney Diseases
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• v.16 no.2
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• pp.80-88
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• 2012

Purpose: The aim of our study was to investigate the characteristics of the peritoneal dialysis (PD) - related peritonitis and to evaluate the effectiveness of the empirical antibiotics recommended by the International Society for Peritoneal Dialysis in Korean children. Methods: We retrospectively reviewed the medical records of 72 children on peritoneal dialysis at the Department of Pediatrics, Asan Medical Center over the period from March 2000 to February 2012. Results: Seventy-nine episodes of peritonitis occurred in 32 patients. The incidence of peritonitis was 0.43 episodes/patient year. There were no significant differences in the incidence of peritonitis in terms of dialysis modality (P=0.459). Twenty-one patients experienced 51 catheter exit-site infections (0.28 episode/patient year). There were no significant differences in the incidence of peritonitis between those with and without history of exit-site infections (P=0.721). Specific pathogens were isolated from 68.4% (54/79) of the patient with peritonitis episodes, including Gram-positive bacteria (n=34), Gram-negative bacteria (n=25) and fungus (n=1). Among Gram-positive bacteria, 85.3% of the isolates were susceptible to ${\beta}$-lactam antibiotics, among Gram-negative rods, 94.7% of the isolates were susceptible to ceftazidime. Among 25 cases with unknown etiologies, 92.0% of cases demonstrated satisfactory responses to cefazolin and ceftazidime. Conclusions: The incidence of peritonitis was 0.43 episodes/patient year. Initial empirical therapy consisting of cefazolin and ceftazidime was appropriate for 91.1% of the PD-related peritonitis treatment. Continuous monitoring for the emergence of the resistant organisms is an important part of the appropriate managements of PD-related peritonitis.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.143-149
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• 2008

Purpose : Urinary N-acetyl-beta-D-glucosaminidase(NAG) and beta 2-microglobulin(B2M) is considered to be a marker of tubulointerstitial injury. The aim of this study was to examine the urinary levels of NAG and B2M in children with various renal diseases. Methods : We studied 21 children(8.9$\pm$4.5 years, Male:Female=14:7) and they were divided into three groups: group I(steroid-sensitive nephrotic syndrome-4 patients), group II(various kinds of glomerulonephritis-4 patients), and group III(normal urinalysis or non-glomerular renal diseases-13 patients). Results : Urinary NAG levels in groups I and II were significantly higher than those in group III(19.4$\pm$11.5 and 30.0$\pm$30.1 vs. 4.7$\pm$3.9, P=0.01), while urinary B2M levels did not differ among the 3 groups, although urinary NAG levels were positively correlated with urinary B2M levels(r=0.49, P=0.03). Urinary NAG and B2M levels were all correlated with proteinuria(r=0.79, P<0.001 and r=0.68, respectively, P=0.001) serum albumin(r=-0.72, P<0.001 and r=-0.57, respectively, P=0.01) and cholesterol(r=0.58, P=0.006 and r=0.56, respectively, P=0.013) levels. Conclusions : Urinary excretions of NAG and B2M are increased in children with steroidsensitive nephrotic syndrome and various kinds of glomerulonephritis, suggesting tubular dysfunction might be present in these diseases.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.164-169
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• 2008

Purpose : There have been some reports on the prevalence of positive antineutrophil cytoplasmic antibody(ANCA) in Henoch-$Sch{\ddot{o}}nlein$ purpura(HSP), but the results were conflicting. We performed this study to evaluate the clinical significance of ANCA(c-ANCA and p-ANCA) in Korean children with HSP. Methods : The medical records of 30 patients(13 boys and 17 girls) aged 6.0$\pm$1.9(5-12) years with a clinical diagnosis of HSP based on the EULAR/PReS criteria were reviewed retrospectively. From the years 2007 to 2008, the sera from children with acute HSP were tested for antineutrophil cytoplasmic antibodies(ANCA). The target antigens of these autoantibodies are proteinase 3(c-ANCA) or myeloperoxidase(p-ANCA). Results : Palpable purpura was seen in all 30 patients(100%), abdominal pain in 20(67%), arthralgia in 17(57%), and renal involvement in 11(37%). Laboratory findings showed leukocytosis in 4 patients(13%), thrombocytosis 18 in(60%), and elevated erythrocyte sedimentation rate in 18(60%). Anti-streptolysin O titers were elevated in 7% of the patients and no patient showed elevation of serum IgA level. The sera from 29 patients were negative for c-ANCA and p-ANCA by indirect immunofluorescence, but only one patient had weakly positive results, which became negative at follow-up. Conclusions : We conclude that c-ANCA or p-ANCA is not an important serologic marker in children with HSP, because it was neither diagnostically nor immunologically specific in children with HSP. These results suggest that ANCA are not involved in the pathogenesis of HSP in children.