The Effects of Job Stress on the Autonomic Nerve Activity of Workers in Manufacturing Industry / 대한산업의학회지

OBJECTIVE: A cross-sectional study was conducted to evaluate the relationships between autonomic nerve activity (i.e., heart rate variability and urinary catecholamines) and job stress. METHODS: The study was conducted on 134 workers from a company producing consumer goods (i.e., diaper, paper towel) located in Cheonan, Korea. Job stress was assessed by Karasek's Job Content Questionnaire (JCQ). Autonomic function was assessed by heart rate variability (HRV) and urinary catecholamines (epinephrine, norepinephrine, and dopamine). Urine samplings, and measurings of HRV, were repeated three times for each shift. Information on demographic characteristics, previous job histories, past medical history, smoking and drinking were also collected. RESULTS: No statistically significant differences were observed in any HRV and urinary catecholamines among the four groups, which were categorized by the Job Strain Model. When data were stratified by work duration, low field HRV was borderline significantly higher in the high strain group in individuals with a shorter work duration (<48.5 months, N=28, p-value of 0.92 by analysis of variance). CONCLUSIONS: Neither HRV nor urinary catecholamines are significantly associated with job stress, as assessed by the Karasek's JCQ. However, HRV seems to be a potential physiological indicator of job stress only in the workers with a shorter work duration.

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