2011 Volume 87 Issue 5 Pages 201-206
In recent years, in the night and shiftwork research, the main interest has switched over to the early morning shift from the night shift. The reason is that there is deterioration of “sleep quality” in the nocturnal sleep before the early morning shift. In this study, therefore, our objective is to investigate “sleep quality” before the early morning shift in a commercial air pilot. Then, we will address his cardiovascular load during sleep from the viewpoint of “karoshi”. The sleep stages and the heart rate during consecutive 24 days were measured by means of “Nemuri Monitor” developed by Aisin Seiki Co., Ltd. The roster of this pilot study consisted of 12 domestic flight days, 9 days off, two standby days, and one layover of an international flight day. The average wake-up time in days of seven early morning flights was 6 hours 12 ± 43 min. And the sleep duration and sleep stages except S 1 reduced with significant differences (p<0.05) compared to those on days off. This trend was showed in SWS (p=0.088) and REMS (p=0.039) even if sleep before the early morning flights added on daytime naps. Heart rate levels of SWS and REMS in sleep before the four consecutive early morning flights increased until the third night (p<0.05), although it returned at the fouth night.