Background: Asthma is a common respiratory disease worldwide. However, few reports are available on the prevalences of asthma and asthma symptoms among Asian subjects. Methods: To determine the prevalences of asthma and asthma symptoms among Japanese subjects, we performed a nationwide cross-sectional, population-based study on Japanese adults aged 20–79 years. Ten areas spread throughout the country were randomly selected. Door-to-door or postal surveys were performed using a translated version of the European Community Respiratory Health Survey questionnaire. Results: The survey was completed by 23,483 participants. The overall response rate was 70.6%. The prevalences of wheeze and current asthma among all participants aged 20–79 years were 10.1% (95% CI: 9.7–10.5%) and 4.2% (95% CI: 4.0–4.5%), respectively. The prevalences among young adults aged 20–44 years were 9.3% (95% CI: 8.7–9.9%) and 5.3% (95% CI: 4.8–5.8%), respectively. The prevalence of current asthma was highest in females aged 30–39 years in comparison with the other gender and age groups. Conclusions: This nationwide study determined the prevalences of asthma and asthma symptoms among Japanese adults. The results provide fundamental information on the respiratory health of Japanese adults.

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To clarify the effects of changing shift schedules from a full-day to a half-day before a night shift, 12 single nurses and 18 married nurses with children that engaged in night shift work in a Japanese hospital were investigated. Subjects worked 2 different shift patterns consisting of a night shift after a half-day shift (HF-N) and a night shift after a day shift (D-N). Physical activity levels were recorded with a physical activity volume meter to measure sleep/wake time more precisely without restricting subjects' activities. The duration of sleep before a night shift of married nurses was significantly shorter than that of single nurses for both shift schedules. Changing shift from the D-N to the HF-N increased the duration of sleep before a night shift for both groups, and made wake-up time earlier for single nurses only. Repeated ANCOVA of the series of physical activities showed significant differences with shift (p<0.01) and marriage (p<0.01) for variances, and age (p<0.05) for a covariance. The paired t-test to compare the effects of changing shift patterns in each subject group and ANCOVA for examining the hourly activity differences between single and married nurses showed that the effects of a change in shift schedules seemed to have less effect on married nurses than single nurses. These differences might due to the differences of their family/home responsibilities.

The correlation was investigated between the frequency of attacks of vibration-induced white finger (VWF) and numbness or coldness of the fingers and legs in patients with vibration syndrome. Some 1687 patients with vibration syndrome were examined and of these 342 chain-saw operators and 277 rock-drill operators had no disease other than vibration syndrome. Then subjects were matched by age and period of treatment within three years. In the last analysis, 20 in the VWF "almost everyday" group or in the "never" group, and 40 in the "occasionally" group were selected from the chain-saw operators, and from the rock-drill operators 32 in the VWF "everyday" or the "never" group and 64 in the "occasionally" group. The present study showed that, with the frequency of VWF attacks, patients had a higher prevalence of coldness not only in the fingers but also in the legs. These findings suggest a correlation between the severity of circulatory disturbances of the upper extremities and that of the lower ones in patients with vibration syndrome. Further studies on circulatory disturbances in the leg are required.

Blood Pressure and Heart Rate Variability in Taxi Drivers on Long Duty Schedules: Fumio KObayashi, et al. Department of Health and Psychosocial Medicine, Aichi Medical University School of Medicine Objective To clarify the mechanisms of excessive risk of cardiovascular disease among taxi drivers, the effects of taxi driving with long work hours on taxi drivers' blood pressure and heart rate variability were examined. Methods We measured the physical activity level, ambulatory blood pressure, and Holter ECG in 34 healthy middleaged male taxi drivers over one work day and the two following non‐work days. The subjects worked for a 24‐h period starting at 07:00, then rested from work for 48 h. Ambulatory blood pressure was recorded automatically at 30‐min intervals over the 72‐h period. Holter ECG records were also kept for the 72 h, and temporal changes in the R‐R interval were analyzed by the complex demodulation method (COM). The amplitude of the high frequency (HF) components (central frequency 0.30 Hz), and the ratio of lowfrequency components (central frequency 0.09 Hz) to high‐frequency components (LlH) was calculated. Results Blood pressure during the work day was significantly higher than that during the non‐work days, with a stronger effect in the hypertensive subjects. There were no significant overall differences in heart rate variability between the work day and the non‐work days, but the temporal patterns of HF and UH on the work day revealed a potent effect of reversed‐phased circadian rhythm for work at night. Conclusions Long duty taxi driving raises blood pressure and may increase cardiovascular risk as a result. The conflict between the circadian rhythms of autonomic nervous activity and work activity at night may also result in increased risk.