Stress and Autonomic Nervous Activity among Taxi Drivers

目的研究工作对出租车司机交感神经和副交感神经活动的影响。方法选取23例血压正常的男性出租车司机和12例高血压男性出租车司机。在动态心电图上，采用复解调方法分析R-R间期的变化。以高频分量（0.30 Hz）幅值作为副交感神经活动参数，低频分量（0.09 Hz）与高频分量（L/H）之比作为交感神经活动参数。比较吸烟前后自主神经活动。每隔30分钟自动记录动态血压。作为参照组，检查了未治疗的健康白班男性工人，有（n=6）和没有（n=7）高血压。结果工作日血压总体上明显增高。工作日的交感神经活动不显著高于节假日。在高血压司机中，副交感神经活动在工作日明显低于假期第一天。在高血压驾驶员中，高交感神经活动持续到工作日的夜间，副交感神经活动在白天被抑制。20 ~ 22时吸烟后5分钟内交感神经活动明显增加，14 ~ 19时吸烟后副交感神经活动受到抑制。结论：出租车驾驶工作使血压维持一整天，增加交感神经活动，抑制副交感神经活动。这种倾向在高血压司机中更为明显。吸烟加速了交感神经活动，抑制了副交感神经活动，尤其是在夜间。

Objectives We investigated work-related effects on sympathetic and parasympathetic nervous activity in taxi drivers.Methods The subjects were 23 normotensive and 12 hypertensive male taxi drivers. On Holter ECG, changes in the R-R interval were analyzed by a complex demodulation method. Amplitude of the high frequency components (0.30 Hz) was used as the parameter of parasympathetic activity, and the ratio of low-frequency components (0.09 Hz) to high-frequency components (L/H) was used as the parameter of sympathetic activity. Autonomic nervous activity was compared before and after cigarette smoking. Ambulatory blood pressure was recorded automatically at 30-min intervals. As reference groups, un-treated healthy day shift male workers, with (n=6) and without (n=7) hypertension were examined.Results Blood pressure on the working day was significantly higher as a whole, in blood pressure. Sympathetic activity on the working days was insignificantly higher than that on holidays. In hypertensive drivers, parasympathetic activity on working days was significantly lower than that on the first day of a holiday. In hypertensive drivers, high sympathetic activity persisted until the night on working days, and parasympathetic activity was suppressed during the day time. Sympathetic activity was significantly increased within 5 minutes after smoking between 20 : 00-22 : 00 hours, and parasympathetic activity was suppressed after smoking between 14 : 00-19 : 00 hours.Conclusions Taxi-driving work maintained blood pressure throughout the day, increased sympathetic activity, and suppressed parasympathetic activity. This tendency was more apparent in hypertensive drivers. Smoking accelerated sympathetic and suppressed parasympathetic activity especially at night.