Development of Predictive Model for Assessment of Grip Strength among Koreans: Data from 2014-2015 Korea National Health and Nutrition Examination Survey / 계명의대학술지

Grip strength is used in the various field to assess the disorder of upper limb. Normative data on the grip strength of population is needed to assess decreased grip strength. In this study, we tried to make a estimating model considering age and anthropometry investigation data, by analyzing 2014-2015 Korean National Health and Nutrition Examination Survey data. The subjects of this study were 10,430 participants who measured grip strength of both hands, have no missing data on anthropometry data and survey. Analysis showed that the grip strength had a curve-shaped correlation which could best be explained by the cubic expression of age, and linear correlation between height, weight and waist circumference. After the stratification of the gender, a prediction formula with age, height, and body weight as independent variables for dominant hand and non-dominant hand grip strength was presented. In addition, the distribution of estimated value to measured value ratio among subjects was suggested, which can be used to assess the abnormal value of grip strength. The distribution of non-dominant hand grip strength to dominant hand grip strength was also suggested, which can be used to determine decreased unilateral grip strength. Several studies have suggested normative value for grip strength by gender and age of Koreans, but there are no consideration for adjusting heightand weight. In this study, the model was developed to calculate the predicted grip force considering age, height, and weight. With the distribution data of measured value to predicted value ratio and non-dominant hand grip strength to dominant hand grip strength ratio, the model can be helpful to assess a reduction in grip strength.

Effect of Follow-up Management on Cerebro-cardiovascular Disease Risk for Small Sized Company Workers / 계명의대학술지

To explore the effect of follow-up management after health examination for the cerebro-cardiovascular disease risk, a survey applied with the KOSHA cerebro-cardiovascular disease risk assessment tool was conducted with 500 workers in small scale enterprise less than 50 employees. They were provided two types of health services; post-examination management and health consultation, and finally compared the cerebro-cardiovascular disease risk changes between 2014 and 2015. In normal group in 2014, only 18.7% of workers who received the follow-up management had elevated risks, while 23.8% of workers who received the health consultation had elevated risks in 2015. In risk group in 2014, only 2.8% of workers who got follow-up management had elevated risks, while 7.7% of workers who got only health consultation had elevated risks in 2015. After adjustment for gender, age, exercise, body mass index, nationality and type of industry, negative correlation was found in association to the follow-up management (odds ratio = 0.87). This study shows that workers with cerebro-cardiovascular disease or who are at high cerebro-cardiovascular risk in small scale enterprise should receive early detection and management using counselling and regular follow-up after periodic health examination. Also the health counselling including preventive education for cerebro-cardiovascular disease is needed for all workers to improve their self-management for health.

Factors related to heart rate variability among firefighters

OBJECTIVES: The aim of this study was to investigate factors associated with heart rate variability in firefighters working in a metropolitan city in South Korea. METHODS: Self-administered questionnaires including Korean Occupational Stress Scale (KOSS) as well as surveys collecting socio-demographic characteristics and work-related factors were given to 962 firefighters. After exclusion for missing data, 645 firefighters were included, and analysis of covaiance adjusted for the general risk factors and job characteristics were used to assess the relationship between heart rate variability and associated factors. RESULTS: SDNN and RMSSD and were decreased in the area of occupational climate of the group with high job stress (p = 0.027, p = 0.036). HF(ln) was decreased in the area of organizational system and occupational climate of the group with high stress that statistically significant level (p = 0.034, p = 0.043). CONCLUSIONS: Occupational climate and organizational system are associated with reduction of heart rate variability. Preventive medical care plans for cardiovascular disease of firefighters through the analysis and evaluation of job stress factors are needed.

Apoptosis of Neuronal Cells Induced by Lead / 대한산업의학회지

Lead is a major environmental and occupational neurotoxicant. It has been shown that long-term exposure to a low level of lead impairs the development of brain. For example, it was reported that lead exposure during the childhood causes a learning difficulty and a memory deficit of children. Neurotoxic agents including the lead are believed to cause neuronal death in developing brain by two mechanisms: apoptosis and necrosis. However, the exact mechanism of neuronal death caused by lead exposure is still not known explicitly. In this study, we conducted a study to clarify a mechanism of hippocampal neuronal cell death caused by lead acetate. Hippocampal neurons were cultured for 14-16 days and treated with lead acetate of 1. 10, 100 1 microM concentrations for 12 hours. With the MTT(methyl tetrazolium test) kit, the viability of neuronal cells was measured. Next, in order to examine apoptosis caused by lead acetate, TUNEL (TdT-mediated d-UTP Nick End Labelling) assay was performed. It has been shown that lead acetate reduced the viability of neuronal cells in a dose dependent manner, especially at the concentration of 100 ~M lead acetate. TUNEL immunostain showed brownish signals in the nucleus of apoptotic cells. The proportions of apoptotic cells in the lead?acetate treated group were more higher than those in the controls and increased as lead acetate concentration increased. From above results, it may be concluded that lead in the hippocampal neuronal cells reduced cell viability and one of mechanisms in neuronal cell death by lead appears to be apoptosis.

Neurobehavioral Performance Changes of Chronic Exposure to Organic Solvents among Textile Processing Workers / 대한산업의학회지

The study was conducted to predict the risk of chronic exposure by neurobehavioral test and to use it as a basic source of the management for workers exposed to organic solvents. The exposed group was selected from coating department of textile processing industry. The unexposed group was selected from those who visited the clinic to take an annual check-up. The author administered WHO-NCTB (neurobehavioral core test battery). Also, Scandinavian Questionnaire 16 was tested by self-administration to find the correlation between subjective symptoms and NCTB results, and to assess the availability of the Questionnaire in mass screening test concurrently. The final analysed subjects were 78 (27 in exposed group and 51 in unexposed group) workers except who had a neurologic disease or systemic disease affecting the central nervous system. In Questionnaire study, there was no significant difference in total neurotoxic symptom scores between the exposed and the unexposed group. In NCTB, the exposed group had lower mean scores than the unexposed group for all tests. When the effect by age and education were considered, there was a statistically significant difference only in pursuit timing test. This study suggests the availability of NCTB and the Questionnaire for the assessment of neurobehavioral change in workers exposed to organic solvents.

Effect of Cadmium on Cytokine Gene Expression in a Human Monocytic Cell Line, THP-1 / 대한산업의학회지

Cadmium, a potent toxic metal, poses a serious environmental threat but the mechanism of its toxicity remains unclear. Also, cadmium is a known immunotoxic agent in animal studies and induces pathophysiological effects by modulating components of immune system. Cytokines are being increasingly recognized as essential mediators of normal and pathologic immune response. Cells of mononuclear phagocytic system are strategically located at portals of entry in humans and therefore may be particularly at risk for cadmium exposure through contaminated air, food, and drinking water. In the present study, we investigated the effect of cadmium cytotoxicity for the monocyte and expression of cytokine gene in the control and cadmium treated human monocytic cell lines using RT-PCR method. The results showed that cadmium inhibited cell proliferation at 0.1mM cadmium treated cells for 24 hours. The TNF-alpha mRNA was expressed in both control and cadmium treated cells but not IL-6 and IL-1 beta The mRNA levels of TNF-alpha were examined during 24 hours culture period, at different time points. The expression of TNF-alpha mRNA increased in both 0.01mM and 0.1mM cadmium treated cells, but did not show dose-response relationship. According to cadmium treated duration, expression of TNF-alpha mRNA was more decreases in 24 hours than 6 hours. The decreased levels of mRNA of TNF-alpha that cadmium suppresses iris production at the transcription level.