[Effect of the long distance truck driving in Hokkaido on cardiovascular system]

We took the blood pressure and ECG of 8 male truck drivers who drive long distances in Hokkaido and observed the conditions under which they work. Most of their driving routes included steep passes, and the weather and the road conditions became worse in winter. Their tasks were not only the driving and waiting but also such manual labor as loading, etc. The mean driving distance of one route was 705 km and it ranged from 159 km to 1,210 km. The mean number of working hours was 27.8 h, and it ranged from 9.2 h to 46.9 h. Blood pressure was higher when driving or loading than when resting or on a day off. The mean systolic blood pressure was over 140 mmHg in 6 cases, and arrhythmia occurred frequently in 4 cases during driving or loading. In 2 cases, in which the driver met with accident, the blood pressure was remarkably high and arrhythmia occurred frequently. Most drivers worked for a very long time in poor conditions and environment. The results of our study suggested that such a heavy work load will affect the cardiovascular system.