In the present study, the influence of the long-term use of air-conditioning in summer on the cortisol rhythm was examined by measuring the rhythm in subjects who had been exposed to air-conditioning for a short [S] or long [L] time. Investigations were conducted twice in July and September. Atmospheric temperature and relative humidity near the subjects were measured for three days in each season. Saliva samples for cortisol analysis were collected every 2 hours during the daytime beginning at 8:00 h with subsequent sampling times at 10:00, 12:00, 14:00, 16:00, 18:00, 20:00 and 22:00 h. A questionnaire on sleep and duration of air-conditioning use was also undertaken. Ambient mean temperature was higher in the S group (mean±SD; 30.8±1.2°C in July, 28.0±0.8°C in September) than in the L group (28.0±1.2°C in July, 27.3±1.0°C in September) (p<0.01), while mean relative humidity did not differ. There were no differences in bedtime, waking time and sleeping hours either between groups or months. Diurnal patterns of salivary cortisol rhythm in July and September were similar in the S group, but the L group had a delayed rise of morning cortisol secretion in September compared with July. These results suggest that long-term exposure to an air-conditioned environment might adversely affect the human cortisol rhythm.

View full abstract

The purpose of this study was to establish an ergonomic basis for the integration of female personnel at military workplaces. The results of anthropometrical and physiological measurements of 1337 male and female subjects (aged 18–25 years) are presented. The empirical design included classical and functional body measures of high ergonomic relevance. Additionally, the isometric forearm-flexor and knee-extensor forces of the subjects were tested as representative variables for their physiological suitability.
With regard to biometric and strength parameters, the present results clearly show only small overlaps between the sexes. Rating the 5th percentile of the male subjects as an exclusion value, the anthropometrical variables (sitting and standing body height measures, shoulder breadth, hand length and breadth etc.) show that 29% up to 72% of the women do not match this criterion. The situation becomes even worse when strength parameters are taken into consideration: Only 26% (knee extensors) respectively 3% (forearm flexors) of the females generate higher forces than the corresponding 5th percentiles of their male counterparts.
The application of the database established in this survey aims at the integration of female personnel at all kinds of military workplaces; our data account for a combination of anthropometrical and physiological variables. In contrast to former systems based on isolated percentile tables, the results of our investigation make multivariate queries possible in optimization processes. This type of combined database is to be considered a useful tool for the evaluation of workplaces and personal equipment, for general ergonomic considerations and for personnel planning purposes to prevent applicants from occupational harm.

View full abstract

Obesity is one of the most common health problems, and is recognized worldwide as an “escalating epidemic.” For the establishment of an obesity-prevention strategy in Japan, it is important to assess the association between obesity and cardiovascular risk factors. Therefore, we conducted anthropometric measures of obesity and investigated the association of obesity with cardiovascular risk factors such as hypertension, diabetes, and dyslipidemia among community-dwelling men (N=85) and women (N=173) aged 40 years and older. Height, weight, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Subjects with a BMI≥25 kg/m² were considered obese (BMI obesity), while men with a WC≥85 cm and women with a WC≥90 cm were classified as obese (WC obesity). In the present study, we defined ‘obesity’ as a BMI≥25 kg/m² or a WC≥85 cm for men, and a BMI≥25 kg/m² or a WC≥90 cm for women. The results of an age- and sex-adjusted logistic regression analysis indicated that BMI obesity was associated with dyslipidemia (p=0.04), WC obesity was associated with dyslipidemia (p=0.07), and ‘obesity’ was associated with diabetes (p=0.06) and dyslipidemia (p=0.01). These results emphasize the importance of preventing obesity in Japan. Therefore, healthcare professionals should measure BMI and WC in order to enhance their assessment of cardiovascular risk.

View full abstract

The number of cellular phone subscribers is increasing every year and there have been reports of health disorders related to the high-frequency radio waves. This paper considers the dependence of Thai university and high school students on cellular phones. A survey form (cellular phone dependence questionnaire: CPDQ) was distributed to 181 female and 177 male Thai university students and to 240 female and 140 male Thai high school students. The surveys were collected, Cronbach α coefficient was calculated, and a factor analysis was performed using the principal factor method and varimax rotation. The total scores were 16.54 to 20.04 and the Cronbach's α coefficients were 0.808 to 0.930. According to a factor analysis of 20 scored items, 4 factors were extracted for both male and female high school students, and the cumulative correlation coefficients of the male and female groups were 64.85% and 62.70%, respectively. Five factors were extracted for male university students and 6 factors were extracted for female university students, and the cumulative correlation coefficients were 58.08% and 57.91%, respectively. The W value results of the Shapiro–Wilk W-test for male university students, female university students, male high school students and female high school students were 0.969, 0.984, 0.964, and 0.913 respectively, thus verifying the normality of the score distributions.
The total scores for the Thai university students were higher than the scores for the Thai high school students. The factor analysis of female high school students confirmed a large difference compared to male university students, male high school students, and Japanese female university students. (The Japanese students were surveyed in an earlier study by Toda et al.). Also, the CPDQ total score was high, which indicated a strong tendency toward dependence.

View full abstract