Objectives: Incresed gamma-glutamyltransferase (GGT) concentration has mainly been used as a biologic marker of alcohol drinking and liver diseases. However, some recent reports have suggested that serum GGT concentration may be an early biomarker of oxidative stress and associated with chronic diseases like hypertension, DM, hyperlipidemia, CHD, stroke etc. In this study, we analysed the factors associated with increased serum GGT level and evaluated the clinical application of serum GGT in predicting the risk of chronic diseases. Methods: The data were collected from 15,546 periodic health examinations, 9,660 males and 5,886 females, done at one university hospital from 2001 to 2003. We analysed self-questionnaire, physical examination and laboratory data. Statistical analyses(t-test, ANOVA, Pearson's correlation analysis, multiple regression analysis and logistic regression analysis) were done by SPSS for windows 10.0. Results: Mean serum GGT levels were quite different according to age, sex, BMI, smoking and alcohol drinking (all P-value <0.001), but were not different by regular vitamin intake or not (P-value = 0.117). There was significant correlation between serum GGT level and the variables (of age, BMI, blood pressure, Hb, fasting blood sugar, total cholesterol, AST and ALT) (all P-value <0.001). In sex-specific multiple regression analysis, increased serum GGT level was significantly associated with age, alcohol drinking, smoking, blood pressure, fasting blood sugar and ALT in males (all P-value <0.001), and with age, alcohol drinking, smoking, Hb, blood pressure, total cholesterol and ALT in females (all P-value <0.05). In sex-specific logistic regression analysis, increased serum GGT level was significantly associated with risk of 'clinical abnormalities'. This risk increased about 13-fold in males and 4.6-fold in females for serum GGT level over the third quatile, compared with under the first quartile. Conclusions: Serum GGT level is increased not only by alcohol drinking or liver diseases, but also by many other factors associated with chronic diseases and behavioral factors. Thus many factors should be considered in evaluating an increase in GGT level, even when within the upper normal range. Serum GGT level may be a predictor for the early development of chronic diseases.

Objectives: This cross-sectional study investigated the relationship between job stress and psychosocial stress among nurses at a university hospital in Incheon, Korea. M e t h o d s: A questionnaire survey was administered to 476 nurses, of which 320 (67.2%) questionnaires were returned and 299 (62.8%) were regarded as containing reliable data for analyses. A structured self-reported questionnaire was used to assess each respondent's sociodemographics, sleep quality, physical burden, job stress and psychosocial stress. Seven domains of occupational stress (e.g., Job demand, Insufficient job control, Interpersonal conflict, Job insecurity, Lack of reward, Organizational system and Occupational climates) according to the Korean Occupational Stress Scale (KOSS) were used and psychosocial stress was measured using Dr. Chang’s PWI-SF (Psychosocial Well-being Index-Short Form). We estimated the relation of job stress to psychosocial stress using univariate and logistic regression analyses. Results: The logistic regression analyses indicated that the groups with high stress in 'Insufficient job control’ (OR=2.67, 95% C.I.=1.37-5.23), ‘Interpersonal conflict’ (OR=2.32, 95% C.I.=1.19-4.51), ‘Job insecurity’ (OR=2.51, 95% C.I.=1.17-5.36), ‘Organizational system’ (OR=2.80, 95% C.I.=1.39-5.63), and ‘Lack of reward’ (OR=2.98, 95% C.I.=1.55-5.74) were more likely to experience high psychosocial stress. C o n c l u s i o n s: Our results tend to suggest that job stress is associated with psychosocial stress. The importance of job stress should be acknowledged and stress management programs need to be instigated to minimize the psychosocial stress caused by job stress.

OBJECTIVES:This study was performed to examine the influence of smoking on the blood cadmium concentration in university students.METHODS:The study included 300 university students. A questionnaire interview was used to collect data. The urine cotinine and blood cadmium levels were measured as biological exposure indices. The data were analyzed using t-tests ANOVA and ANCOVA.RESULTS:The median value of blood cadmium concentration was equal in both males and females (0.8microgram/liter). This level was relatively low in comparison with the reference value suggested by WHO (2001). ANCOVA showed that smoking related variables, urine cotinine and smoking amount, were significantly associated with the blood cadmium level (P=0.004, 0.015). However, the values with regard to traffic related air pollution were not significantly associated with the blood cadmium level.CONCLUSIONS:Smoking is an important source of nonoccupational cadmium exposure in young people. The Blood cadmium level is at least 10% higher in active smokers than in passive or nonsmokers. The level of urine cotinine can be used as an indicator of non-occupational exposure of respirable cadmium due to smoking, as there is a good correlation bestween smoking amount and the urine cotinine level.

Objectives: Alcohol drinking, obesity, and reduced physical activity are commonly related to oxidative stress, which induces plasma membrane-bound protein damage in hepatic cells and elevates serum γ-GTP. We have a hypothesis that a long commuting time may induce oxidative stress. This study was undertaken to investigate the relationship between commuting time and serum γ-GTP level. Methods: Questionnaires were administered to 717 male workers who had worked at Kimpo airport until the year 2000, and had then moved to Incheon airport and were working there in 2002. The questionnaire included items concerning commuting time, sleeping time and alcohol consumption. Physical examination and laboratory data were also collected. Results: Serum γ-GTP level was significantly and positively correlated with commuting time, body mass index, systolic blood pressure, diastolic blood pressure, hemoglobin, glucose, total cholesterol, AST, ALT and alcohol consumption. Multivariate regression analysis demonstrated that serum γ-GTP level is significantly associated with commuting time, after considering the other covariates. Conclusions: Commuting time is one of the factors that affects serum γ-GTP level in male workers.

Objectives: The occupational & environmental medicine clinic plays an important role in the growth and advance of occupational & environmental medicine. This study analyzes the disease distribution and referral routes of patients in an occupational & environmental medicine clinic of a university hospital. Methods: 843 Agent Orange cases and 839 other cases were treated in the clinic over a period of 4 years. The Agent Orange cases were excluded from this study. Distributions of age, sex, disease and referral route were examined according to the medical records of the hospital. Results: 654 of the patients in the study population were male(77.9 %) and 185 were female(22.1 %). The most common age group consisted of patients in their forties. The number of cases has been increasing annually(1998, 146 cases; 1999, 174 cases; 2000, 247 cases; 2001, 272 cases). The source of the cases were as follows: health examination, 548(65.4 %); health management service, 132(15.7 %); self-referral, 125(14.9 %); physicians in other hospitals, clinics, 18(2.1 %); and physicians in other clinic in the hospital, 16(1.9 %). The most commonly occurring disease was liver disease(28.6 %), followed by respiratory disease(12.8 %), gastroenteric disease(10.3 %) and musculoskeletal disease(8.7 %). When the clinic was first opened, most cases came through ‘health examination’. Subsequently the number of cases arising from ‘self-refferal’and ‘health management services’were increased. The disease distribution has also changed as the referral route distribution evolved. Conclusions: In order to expand the work of the clinic, primary cares for patients who came from ‘health examination’will be needed to settle down the clinic at the beginning. Thereafter, specialized services need to be developed for cases originating from ‘self-referral’and from referral by other organizations. Increasing the number of cases needs to go hand in hand with the development of good management skills.