A Response Pattern of Mailing Questionnaires / 예방의학회지

No abstract available.

Genetic Susceptibility of Breast Cancer in Korea: Molecular Epidemiological Approaches / 한국유방암학회지

No abstract available.

Sick Building Syndrome and the Related Factors in Office Workers / 예방의학회지

A cross-sectional study was conducted to investigate the prevalence and risk factors for symptoms associated with sick building syndrome in four office buildings located in Seoul. Information on personal factors, job-related factors, and medical history were collected using self-administered questionnaires modified from the National Institute for Occupational Safety and Health Indoor Air Quality questionnaire in 321 office workers in these buildings. The prevalence of general and irritant symptom groups was higher than the prevalence of dermatologic and respiratory symptom groups. Daily total work time, work time in the office, and work time with video display terminals(VDT) were identified as the risk factors for symptom groups associated with sick building syndrome by multiple linear logistic regression analysis. In conclusion, these results indicated that the symptom prevalence in this study is similar with the results reported from previous studies conducted in other countries and work time and work with VDT are related to sick building syndrome in Korea.

Lung cancer, chronic obstructive pulmonary disease and air pollution / 예방의학회지

BACKGROUND: Although there are growing concerns about the adverse health effect of air pollution, not much evidence on health effect of current air pollution level had been accumulated yet in Korea. This study was designed to evaluate the chronic health effect of air pollution using Korean Medical Insurance Corporation (KMIC) data and air quality data. Medical insurance data in Korea have some drawback in accuracy, but they do have some strength especially in their national coverage, in having unified ID system and individual information which enables various data linkage and chronic health effect study. METHOD: This study utilized the data of Korean Environmental Surveillance System Study (Surveillance Study), which consist of asthma, acute bronchitis, chronic obstructive pulmonary diseases (COPD), cardiovascular diseases (congestive heart failure and ischemic heart disease), all cancers, accidents and congenital anomaly, i.e., mainly potential environmental diseases. We reconstructed a nested case-control study with Surveillance Study data and air pollution data in Korea. Among 1,037,210 insured who completed questionnaire and physical examination in 1992, disease free (for chronic respiratory disease and cancer) persons, between the age of 35-64 with smoking status information were selected to reconstruct cohort of 564,991 persons. The cohort was followed-up to 1995 (1992-5) and the subjects who had the diseases in Surveillance Study were selected. Finally, the patients, with address information and available air pollution data, left to be 'final subjects'. Cases were defined to all lung cancer cases (424) and COPD admission cases (89), while control groups are determined to all other patients than two case groups among 'final subjects'. That is, cases are probable chronic environmental diseases, while controls are mainly acute environmental diseases. For exposure, Air quality data in 73 monitoring sites between 1991 - 1993 were analyzed to surrogate air pollution exposure level of located areas (58 areas). Five major air pollutants data, TSP, O3, SO2, CO, NOx was available and the area means were applied to the residents of the local area. 3-year arithmetic mean value, the counts of days violating both long-term and shot-term standards during the period were used as indices of exposure. Multiple logistic regression model was applied. All analyses were performed adjusting for current and past smoking history, age, gender. Results: Plain arithmetic means of pollutants level did not succeed in revealing any relation to the risk of lung cancer or COPD, while the cumulative counts of non-attainment days did. All pollutants indices failed to show significant positive findings with COPD excess. Lung cancer risks were significantly and consistently associated with the increase of O3and CO exceedance counts(to corrected error level - 0.017) and less strongly and consistently with SO2 and TSP. SO2and TSP showed weaker and less consistent relationship. O3and CO were estimated to increase the risks of lung cancer by 2.04 and 1.46 respectively, the maximal probable risks, derived from comparing more polluted area (95%) with cleaner area (5%). CONCLUSIONS: Although not decisive due to potential misclassication of exposure, these results were drawn by relatively conservative interpretation, and could be used as an evidence of chronic health effect especially for lung cancer. O3might be a candidate for promoter of lung cancer, while CO should be considered as surrogated measure of motor vehicle emissions. The control selection in this study could have been less appropriate for COPD, and further evaluation with another setting might be necessary.

Biomarkers of Susceptibility in Bladder Carcinogenesis / 대한산업의학회지

Owing to the development of molecular biological techniques to identify new biomarkers of bladder cancer, the information obtained from the studios in which newly developed biomarkers are applied potentially useful in screening of general population, diagnosis of patients, predicting biological behavior and prognosis, and exposure assessments. Despite of rapid development there are a few review about the biomarkers in bladder cancer from which grogs summary of results as well as their optimal function can be considered. This study was carried out in biomarkers of bladder cancer by reviewing the literature to assess the usefulness and stapes of researches for biomarkers of bladder cancer on high risk groups, general population and patients. The biomarkers of bladder cancer were classified by Weinstein's model of carcinogenesis, simple classification of exposure-discase in classical epidemiology, classification by conception of exposure-disease continuum on molecular epidemiology, and application of biomarkers. Two biomarkers, N-acetylation enzyme and Glutathion S-transferase, which had been studied extensively in molecular epidemiology were selected and reviewed. Although the generalization, prediction and diagnosis of bladder cancer based on a single biomarker give rise to trouble due to intravariation of bladder tumor and heterogeneity of biomarkers variation, searching for more specific tumor markers may accurately lead better prediction of prognosis and better estimation of treatment response. The usefulness of both N-acetylation enzyme and glutathion 5-transferase in high-risk groups who have exposes to carcinogen may be more valuable. However more informations are neede in order to apply these biomarkers in clinical practices in further studies.

A case-crossover study between air pollution and hospital emergency room visits by asthma attack / 대한산업의학회지

OBJECTIVES: This study, using case-crossover design, search a relationship between changing levels of air pollutants and asthma attack in asthma patients. METHODS: We searched the daily total number of asthmatic patients at hospital' s emergency room in Seoul, Korea by investigating total 49 general hospitals emergency room records. Otherwise, We investigated medical records of asthmatic patients at one of the 49 hospitals we have searched. We investigated addresses that they are living, diagnosis, smoking history, whether respiratory infection or not, medications. We analyzed the data by 1:m conditional logistic regression used when matched case-control study is analyzed. Control periods were chosen by bidirectional paired matching technique 7, 14 days before and after case periods. RESULTS: the relative risk of asthmatic attack by 100 ppm ozone increase between June and September were 1.348(95 % CI = 1.010~1.619). Between November and February, the relative risk by 100 /m TSP increase, 100ppb sulfur dioxide and nitrogen dioxide were respectively 1.278(1.010~1.619), 1.237(1.019~1.502), 1.285(1.006~1.640). In stratified analysis, the relative risk were significant when the asthmatic patients were children aged 15 years or below, when there were respiratory infection, and when the patients took medications irregularly CONCLUSIONS: There was statistically significant association between ambient levels of air pollutants and asthmatic attack. So, we have to exert our efforts to minimize the air pollution effectively, to protect public health from air pollution.

Association Study of Functional Catechol-O-Methyltransferase Gene Polymorphism in Korean Schizophrenia / 신경정신의학

OBJECTIVES: Catechol-O-methyltransferase(COMT) is involved in the degradation of catecholamine neurotransmitters and has been investigated as a candidate gene in schizophrenia. Recently, possible relationship between functional COMT gene polymorphism and schizophrenia has been suggested. To address the possible role of functional COMT gene polymorphism in the predisposition to schizophrenia, we carried out an association study in Korean schizophrenic patients and controls. METHODS: One hundred and three Korean inpatients diagnosed as schizophrenia and 103 age and sex matched controls were selected as study subjects. Patients were subgrouped into two groups on the basis of history of aggressive behavior, family history of schizophrenia and related disorders, and age at onset. We determined COMT genotypes using PCR of the relevant region followed by digestion with NlaIII and electrophoresis. RESULTS: No significant differences of allele and genotype frequencies were noted between patients and controls. However, when patients were categorized by the presence of family history of schizophrenia and related disorders, patients with family history showed almost 4-fold higher frequency of having COMT L allele containing genotype compared to controls(p=0.02, OR=3.9, 95% CI=1.10-14.33). CONCLUSION: Although our results do not support an association between functional polymorphism of COMT gene and schizophrenia overall, the findings suggest an association between functional COMT gene polymorphism and familial schizophrenia. Further studies with large samples are needed to confirm this association.

Reliability and Validity of the Korean Version of ISAAC Questionnaire / 예방의학회지

Recent increases of asthma and allergies in childhood made the need for a standardized approach to international and regional comparisons of their prevalence and severity. To address these issues, "International Study of Asthma and Allergies in Childhood (ISAAC)" is currently underway. In Korea, "Nationwide Study of Asthma and Allergies in Korean Children" began in 1995 according to ISAAC protocol. ISAAC written and video questionnaires were used in this survey, but their reliability and validity were not evaluated properly yet. In this study, our aim was to evaluate the reliability and validity of two kinds of questionnaires and their usefulness in international and regional comparisons. The test and retest of two questionnaires were completed by male(n=110) and female(n=111) middle school students with two and three weeks interval each. Kappa(or weighted kappa) were calculated from each questions and validity coefficients were estimated from those statistics. In Korean version of written questionnaire, the questions for allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and food allergy proved to have high kappa values(or weighted kappa values) and validity coefficients and they can be used in further studies without any correction. But some questions about asthma(especially nocturnal cough, wheezing in exercise, and severe asthma) and drug allergy need to be revised for better understanding to study subjects. Video questionnaire has the same degree of reliability and validity when compared to written questionnaire and this is the unexpected result. Accordingly, it also need to be revised to overcome the racial and cultural differences of the study subjects. In conclusion, the Korean version of written and video questionnaires may be considered to be useful methods in international and regional comparisons of asthma and allergic diseases in childhood after correction of some questions.

Incidence rate of hepatitis B: results of a record linkage study among healthy Korean males

A stable, liver disease-free cohort of 369,725 was reconstructed as of 1984 for the study of hepatitis B virus seromarkers and liver diseases. The cohort consisted of male beneficiaries of the Korea Medical Insurance Corporation (KMIC) over 30 years of age and living nationwide. Subjects who were both negatives for HBsAg and anti-HBs (N = 274,037) were selected for incidence of hepatitis B. Data on test results of HBsAg and anti-HBs in 1984 and on hepatitis B occurrence during 1985-1986 were collected from the files of the KMIC. Linkage was done between these two data sets to measure the incidence rate through a longitudinal observation of the male population. Correction against misclassification error and duplicate claims was done by a sample survey and verification procedures. The incidence rate of hepatitis B was 17.13 per 100,000 person-years for acute viral hepatitis B and 15.74 for chronic hepatitis B, respectively. An increasing age-dependent pattern for acute hepatitis B was not so prominent in this population. However, the incidence rate of chronic hepatitis B steadily increased with age. The relative risk, estimated by a log-linear model for rate and constant hazard, was significantly higher in the over-60 age group than in the others. The incidence rate in the lower socioeconomic class was higher than in the others, although statistically not significant.

Association of Genetic Polymorphism of Glutathions S-transferase M1 and T1 and Bladder Cancer / 대한암학회지

PURPOSE: Smoking and high-risk occupation are known to be the risk factors of bladder cancer. The carcinogen-metabolizing enzymes in human body such as GSTM1 and GSTT1 have also been regarded as risk factors in many cancers because the activities of those enzymes play a role in metabolizing the carcinogen. A case control study was conducted to evaluate the role of known risk factors (smoking and high-risk occupational history) and the genetic polymorphism of GSTM1 and GSIT1 in blader carcinogenesis in Korean men. MATERIALS AND METHODS: The pathologically proven bladder cancer cases were selected from three hospitals in Seoul (Seoul National University Hospital, Boramae Hospital, and Sam-Sung Medical Center) and the patients older than 40 years of age with the nonmalig nant urinary tract diseases were selected as the controls from the same hospitals. The informations of demographical characteristics, smoking, and occupational history was obtained by the trained interviewer and the genetic polymorphisms of GSTM1 and GSTT1 were assayed by multiplex PCR. The statistical analysis was performed by multiple logistic regression. RESULTS: Neither smoking nor high-risk occupational history was statistically significant risk factor of the bladder cancer. However, the GSTM1 null-type showed borderline significance (OR 1.49; 95% CI 0.92-2.41) and both GSTM1 and GSlT1 null-type was statistically significant risk factor of bladder cancer when compared with both normal genotype (OR-2.43; 95% CI 1.13-5.24) after age and smoking history were adjusted. CONCLUSION: The concurrent null-type of GSTM1 and GSTT1 increases the risk of bladder cancer in Korean men.

The Association of Workplace Cumulative Noise Exposure and Blood Pressure / 대한산업의학회지

OBJECTIVES: The association of workplace cumulative noise exposure and blood pressure was investigated in this study using cross-sectional design. METHODS: The study population comprised 852 manufacturing male workers of whom occupational health examination data, questionnaire and personnel records were available. Workplace ambient noise monitoring data was used for calculating individual cumulative noise exposure level. Mean of each systolic and diastolic blood pressure of occupational health examination data was used for individual systolic and diastolic blood pressure level. Possible confounding variables including family history of hypertension, smoking habit, alcohol drinking habit were collected by questionnaire. On the basis of job location and duration of work at the location, a cumulative time-weighted average noise level was calculated for each workers. According to this cumulative noise exposure level, each study subject was categorized as low noise exposure group, moderate noise exposure group, high noise exposure group, very high noise exposure group. Among noise exposure groups, mean of systolic and diastolic blood pressure was compared after adjusting possible confounding variables such as age, body mass index, serum cholesterol level, family history of hypertension, smoking history, alcohol drinking habit. RESULTS: After adjusting possible confounding variables, noise exposure group was significant explanatory variables for both systolic and diastolic blood pressure, and mean of both systolic and diastolic blood pressure of very high exposure group was higher than that of low exposure group. CONCLUSIONS: These findings suggested that the high cumulative noise exposure might elevate the blood pressure.

Development of Questionnaire for Evaluating Health Effect Associated with Air Pollution / 예방의학회지

This study was conducted to develope and evaluate the reliability and the validity of a questionnaire in order to determine the applicability as a screening tool for estimating environmental exposure and health effects related to air pollution. The questionnaire was developed with adopting some items of others such as ISAAC or ATS-DLD. And then we performed test-retest to 89 middle school students and their mothers at interval of three months. Cohen's Kappa values, weighted Kappa values, Spearman's correlation coefficients, and Pearson's correlation coefficients for each item were computed as reliability coefficients. The validity coefficients and validity coefficient bounds were also obtained by simply using these reliability coefficients. As results, Kappa ranged broadly from 0.10 to 0.61 of the items 'diet', 0.52~0.79 of the environmental tobacco smoke, 0.39~0.44 of the functional categories of surrounding environment, and 0.54~0.63 of the using transportation systems; these items were regarded as confounding factors. For items related to health outcomes, Kappa ranged from -0.02 to 0.37 in the respiratory system of past medical history, and from 0.11 to 0.55 in the current health status. But Kappa of the others were over 0.60. In conclusion, if some items can be corrected or modified, the questionnaire developed in this study can be used as a tool for evaluating environmental exposure and health effects associated with air pollution.

Prevalence and Epidemiological Characteristics of Urolithiasis for Adults Aged 40-79 in Seoul, Korea / 대한비뇨기과학회지

No abstract available.

Is Breast Cancer Incidence Rate Further Increasing in Korea? / 한국역학회지

Breast cancer ranks second to stomach cancer as a primary cancer site. An increasing trend in mortality and morbidity of breast cancet has been shown since 1980s. Studies on migrant populations, in which higher incidences were shown than population in their motherlands, indicated the importance of environmental factors on breast cancer development. Older age, family history of breast cancer, early menarche, late menopause, late full-term pregnancy, never-having had a breast-fed child, and postmenopausal obesity were idenrified as risk factors in Korea. These are not different from risk factors detected in western countries. Nevertheless, a

Cigarette Smoking, Alcohol Consumption, and Breast Cancer in Korea / 한국역학회지

A hospital-based case-control study was conducted to assess the relationship between cigarette smoking, alcohol consumption, and the risk of bgreast cancer in Korea. Histologically confirmed incident cases of breast cancer(n=146) were selected from the inpatients at the Department of Surgery, Seoul National University Hospital and Borame Hospital during 1994 to 1997. Women ithout self-reported past history of any malignandies were regarded as controls and selected at the same hospitals during the same period(n-153). Information on life-styles including cigarette smoking, alcohol drinking, and reproductive history were obtained by direct interview using standardixed questionnaire. Each case was matched with one control by 5-year age category(n=146). Adjusted odds ratios and 90% confidence intervals were estimated by unconditional linear logistic regression model. For smokers, age at first smoking was significantly associated with the breat cancer risk(adjusted OR=14.1, 90% CI=1.24-364.2). Particularly noteworthy was an increasing tendency of the breast cancer risk with the duration of alcohol consumtion in years aong alcohol drinkers(ptrend<0.1). These findings suggest that cigarette smoking at an earlier age and alcohol intake might contribute to the risk factor of breast cancer in Korean women. Further investigation on the association between genetic polymorphism of xenobiotic metabolism enxymes of environmental carcinogens and breast cancer should be needed.

The Estimation of Breast Cancer Disease-Probability by Difference of Individual Susceptibility / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The aims were to evaluate the main risk factors (RFs) of breast cancer and to estimate the individual disease-probability from combinations of RFs in Korean female. MATERIALS AND METHODS: We conducted case-control study of 1, 687 incident cases of invasive carcinoma and 1, 238 controls during 1996~2000. A breast cancer disease-probability model was established by a general modeling process using a multivariate logistic regression model, which included the main Korean RFs and synergistic interaction-terms. RESULTS: The main Korean RFs selected were age, family history of second relatives, BMI, age at first full term pregnancy, breast-feeding, and a special test on the breasts. Two synergisms were observed between age and breast-feeding, and between special test and age at first fullterm pregnancy. The disease-probability and model are shown in Table 4, and Appendix 1. CONCLUSION: The availability of previous Western models was limited for Korean female due to the differences inhazard-rates and the characteristics of breast cancer between Asian and Western females. Due to limited basic data, i.e. incidence, hazard-rate and cancer-cohorts, the developing-probability of breast cancer for Korean females was not calculated. Therefore, the disease-probability was calculated instead. This approach might be more beneficial for Koreans, and help in the decision- making for regular screening or hospital visit-interval, counseling in breast-cancer clinics, prescribing high-risk population, and in educating for primary prevention, although it over-estimates the relative probability compared to the developing-probability and the 65% predictive validity.

Incidence estimation of thyroid cancer among Koreans

The medical records of inpatients with diagnoses of either ICD-9 193(malignant neoplasm of the thyroid gland) or 226(benign neoplasm of the thyroid gland) in the claims sent in by medical care institutions throughout the country, to the Korea Medical Insurance Corporation (KMIC) during the period from January 1, 1986 to December 31, 1987 were abstracted. These records were abstracted in order to identify and confirm new cases of thyroid cancer among the beneficiaries of the KMIC. Using these data, the incidence rate of thyroid cancer among Koreans was estimated as of July 1, 1986 through June 30, 1987. The crude rates were estimated to be 0.76(95% Cl: 0.63-0.87) and 3.87(95% Cl: 3.60-4.14) per 100,000 in males and females, respectively, and the cumulative rates for the age spans 0-64 and 0-74 in males were 0.06% and 1.10%, respectively. In females, those were equally 0.35%. The age-adjusted rate for the world population was 0.93 per 100,000 in males, which is one of the lowest levels in the world. However, the adjusted rate in females was 3.96 per 100,000, which is an average level and very similar to that of the Chinese in Singapore and Shanghai. A similar tendency was shown in the case of the truncated rates for the age group of 35-64, which was 1.91 per 100,000 in males and 8.82 per 100,000 in females.

Incidence estimation of stomach cancer among Koreans

A series of incidence estimation studies of cancers among Koreans through a nationwide survey has been undertaken by authors since 1988. The medical records were studied of inpatients with diagnoses of either ICD-9 151 (malignant neoplasm of the stomach), or 197 (secondary malignant neoplasm of the respiratory and digestive systems), or 211 (benign neoplasm of other parts of the digestive system) in claims sent in by medical care institutions throughout the country to the Korea Medical Insurance Corporation (KMIC) during the period from January 1, 1986 to December 31, 1987. These records were abstracted in order to identify and confirm the new cases of stomach cancer among the beneficiaries of the KMIC, which covers about 10% of whole Korean population. Using these data from the KMIC, the incidence patterns of stomach cancer among Koreans were estimated as of July 1, 1986 to June 30, 1987. The crude incidence rates of stomach cancer among Koreans are estimated to be 36.2 (95% tonfidence interval; 35.3-36.9) and 21.0 (95% CI; 20.3-21.6) per 100,000 in males and females, respectively. The cumulative rates for age spans 0-64 and 0-74 are 3.8% and 7.3% in males, respectively. In females they are 1.8% and 3.0%. The adjusted rates for the world population are 57.9 in males and 25.1 in females, which are similar to those of Shanghai, China '78-'82 but lower than those of Osaka, Japan. The truncated rates for ages 35-64 years, however, are 108.3 in males and 49.1 in females, which may be the highest in the world. Among Koreans in Korea, an increased risk of stomach cancer in this age group is the notable finding. Incidence patterns of stomach cancer by age, sex, and area, which are the first report in Korea, are analyzed and presented.

The Present Status and Perspective of Nationwide Occupational Diseases Surveillance System / 대한산업의학회지

No abstract available.

A Case-Control Study of the Association between Glutathione S-transferase (GST) M1 and T1 Genetic Polymorphism and Breast Cancer in Korean Women: Preliminary report / 대한암학회지

PURPOSE: A hospital-based case-control study was conducted to evaluate the role of glutathione-S-transferase (GST) Ml and Tl genetic polymorphism for developing breast cancer in Korea. MATERIALS AND METHODS: Histologically confirmed incident cases of breast cancer (n=176) were selected from inpatients at the Department of General Surgery, Seoul National University Hospital (SNUH), Borame hospital, and Asan Medical Center from 1994 to 1998. Women with no self-reporting past history of any malignancies who were selected from the inpatients at the same department at three hospitals during the same period served as controls (n 118). Information on the life-styles including reproductive factors were obtained by interview using questionnaire. Age and education adjusted odds ratio and 95% confidence interval were estimated by unconditional linear logistic regression. RESULTS: These subjects had similar risk factors for developing breast cancer to general Korean population based on other epidetniologic studies previously performed in Korea. GSTI1 null type showed a borderline significance relation in the breast cancer risk (adjusted OR=1.6, 95% CI=0.96-2.62), however, GSTM1 null type was not significant (adjusted OR=1.1, 95% CI=0.67-1.80). Particularly noteworthy was an borderline increasing tendency (p<0.1) of the breast cancer risk with the risk null genotypes assessed by multivariate logistic regression model after adjusting age and education: the putative low-risk genotype with both GSTM1 & GSTT1 wild type, OR=1.0; one putative high risk genotype with GSTM1 null or GSTMl null type, OR=1.9 (95% CI=0.92-3.74); all two putative high risk genotype with both GSTM1 & GSTT1 null type, OR=2.0 (95% CI=0.89-4.68). CONCLUSIONS: These findings suggest that both GSTMl and GSTT1 null type might be the risk factor of developing breast cancer in Korean women. Further investigation with larger sample size should be needed to provide more concrete information on the role of GST genetic polymorphism in breast cancer.