Application of autonomic nervous function evaluation to job stress screening.

The present study focuses on the evaluation of autonomic nervous function, which is increasingly being used as an objective measure of fatigue state. It has recently been reported that autonomic nervous activity, which is expressed as total heart rate variability (HRV) power, is associated with, and can be used as an objective measure of, mental and physical fatigue. Total HRV power (log (LF + HF)) has been shown to decline with ageing, and thus cannot be utilized as a fatigue index in populations with a different age composition. In the present study, we devised standard scores (deviation value) for autonomic nervous activity corrected for individual age calculated from the distribution of such activity in individual age cohorts. This allowed us to accurately evaluate an individual's autonomic nervous activity, even when that individual was part of a group with members of different ages. Standard scores were quantified using autonomic nervous function data gathered from 1,969 healthy individuals (age range 20-77 years). The efficacy of this method in mental health screening was investigated by evaluating both autonomic nervous function and subjective levels of fatigue among corporate workers. Based on results from the Brief Job Stress Questionnaire recommended by the research team of the Ministry of Health, Labour and Welfare, 103 participants were divided into two groups (a high-stress group [n = 17] and a non-high-stress group [n = 86]). Visual analog scale (VAS) scores for all fatigue-related symptoms were significantly higher among the high-stress than among the non-high-stress group (p < 0.01). The mean standard score for autonomic nervous activity was 56.3 for the non-high-stress group. The score for the high-stress group was significantly lower, at 47.9 (p < 0.01), indicating that autonomic nervous function was reduced among participants who experienced high stress. According to an analysis of raw and standard scores in each domain, autonomic nervous activity did not significantly correlate with stress-causing factors (e.g., overwork) or other factors affecting stress responses (e.g., support from supervisors and colleagues), but did exhibit a significant positive correlation with physical and mental responses to stress (r = 0.334, p < 0.01). Lower raw scores for mental and physical responses to stress represent stronger subjective symptoms. Moreover, greater stress responses were found to be associated with lower standard scores for autonomic nervous activity. In terms of fatigue-related symptoms rated using the VAS, autonomic nervous activity negatively correlated with mental stress, physical stress, fatigue/malaise, depressed mood, anxiety/fear, tension, irritation/anger, cognitive decline, and muscle/joint/general pain, and positively correlated with motivation/vitality. Reduced autonomic nervous activity was observed with high stress, confirming that standard scores for autonomic nervous activity are associated with mental and physical responses to stress and subjective fatigue-related symptoms. These results indicate that the evaluation of autonomic nervous activity using standard scores (deviation value) is a useful tool for the objective measurement of fatigue state, even in groups with members of different ages, and can be applied as a useful objective health index to evaluate industrial fatigue.

A potential biomarker for fatigue: Oxidative stress and anti-oxidative activity.

We sought to determine whether oxidative stress and anti-oxidative activity could act as biomarkers that discriminate patients with chronic fatigue syndrome (CFS) from healthy volunteers at acute and sub-acute fatigue and resting conditions. We calculated the oxidative stress index (OSI) from reactive oxygen metabolites-derived compounds (d-ROMs) and the biological antioxidant potential (BAP). We determined changes in d-ROMs, BAP, and OSI in acute and sub-acute fatigue in two healthy groups, and compared their values at rest between patients with CFS (diagnosed by Fukuda 1994 criteria) and another group of healthy controls. Following acute fatigue in healthy controls, d-ROMs and OSI increased, and BAP decreased. Although d-ROMs and OSI were significantly higher after sub-acute fatigue, BAP did not decrease. Resting condition yielded higher d-ROMs, higher OSI, and lower BAP in patients with CFS than in healthy volunteers, but lower d-ROMs and OSI when compared with sub-acute controls. BAP values did not significantly differ between patients with CFS and controls in the sub-acute condition. However, values were significantly higher than in the resting condition for controls. Thus, measured of oxidative stress (d-ROMS) and anti-oxidative activity (BAP) might be useful for discriminating acute, sub-acute, and resting fatigue in healthy people from patients with CFS, or for evaluating fatigue levels in healthy people.

Social development conditions and related factors for children in Japanese kindergarten in Shanghai, China.

OBJECTIVE: The aim of this study is to clarify the social development conditions and related factors for children in Japanese kindergarten in Shanghai, China. METHODS: The target schools were three Japanese kindergartens in Shanghai, three in Wakayama, Japan, and three in Osaka, Japan. The target kindergarten children were all 5- or 6-year-olds. We used an anonymous questionnaire to the guardian of the child. The question items related to social development, lifestyle and daily activities of the child, and rearing awareness and conditions of the guardian. Social development was scored by Strength and Difficulties Questionnaires (SDQ). RESULTS: The number of respondents was 246 (Shanghai group 72, Wakayama group 86, Osaka group 88). The median value of the score of total difficulties and prosocial behavior, SDQ subscale, and the proportion of children judged as low need showed no significant difference. Results of multiple logistic regression analysis showed that the frequency of eating fast-foods and the rearing condition "I become anxious or lose enthusiasm for childrearing when the child is recalcitrant" were the factors relevant to prosocial behavior in the Shanghai group. In the Wakayama group, the hours spent daily watching TV was designated as the relevant factor. In the Osaka group, hours spent daily playing outdoors was found to be the relevant factor. CONCLUSIONS: Social development of children in Japanese kindergarten in Shanghai was the same as that of those living in Japan. The factors relevant to prosocial behavior in the Shanghai group were different from those in the two cities in Japan. This study may show the important points to keep in mind for childrearing abroad.