There are an increasing number of reports that job related factors are associated with hypertension, sleep deprivation, obesity and diabetes. This study analyzed the relationship of working type, working hours and the prevalence of metabolic syndrome. The study’s subjects were 2,777 employees (1,446 males and 1,331 females) over 19 years old and their data was from the Korea National Health and Nutrition Survey (2015). The type of work was divided into day work and shift work. The working hours were divided into less than 40 hours, 40 to 49 hours, 50 to 59 hours and 60 hours or more per week. As a result of this study, the prevalence of metabolic syndrome was 26.4% of the males and 19.1% of the females. Generally there was no relationship between metabolic syndrome and type of work (day work and shift work). As a result of analysis of working hours and metabolic syndrome, the workers who worked 40-49 hr were associated with a decreased prevalence of metabolic syndrome as compared to that of workers who worked less than 40 hr (odds ratio: 0.47, 95% confidence interval: 0.24-0.95, p<0.05). Further, positive relationships were found between the number of work hours and the prevalence metabolic syndrome for specific females who worked over 40 hr/wk. It can be concluded from the results that it is important to help workers avoid metabolic syndrome through setting appropriate work hours.

This studies were measure the cortisol from salivary and serum of fire-fighters, who are relatively always exposed to highly dangerous and unsafe working conditions in which they should bring a fire under control or rescue people in danger situations et cetera, therefore both physically and mentally stressed-out, and comparatively analyzed the correlation between the two cortisol levels. The salivary and serum samples of 133 active fire fighters. These were collected at 8:30am, when leaving for work. The salivary cortisol analysis was carried out with enzyme immunoassay, and the serum cortisol analysis utilized chemiluminescence immunoassay. On the morning of testing, the salivary cortisol concentration was 1.92±0.73(0.51~5.85)㎍/㎗, while the cortisol concentration of serum was 14.93±4.23(4.45~25.85)㎍/㎗. Results were grouped according to ages, smoking, drinking habit, and duty type. Higher smoking and drinking produced a statistically significant increase in salivary and serum cortisol concentration. Cortisol concentrations according to type or duty followed by emergency rescue, fire suppression, rescue, miscellaneous. There is a statistically significant correlation between salivary and serum cortisol concentrations. The results show that a significant correlation between salivary and serum cortisol concentrations exists in fire fighters. It is judged that noninvasive methods salivary cortisol could be used in place of serum cortisol to measure cortisol levels when considering factors such as convenience of sample collection and cost.