Abstract：
OBJECTIVE: Permanent night workers conceivably show better adaptation of circadian rhythms to night work than shift workers and therefore better possibilities of obtaining sufficient sleep of good quality after night shifts. We investigated the effect of night shifts including number of consecutive shifts on sleep among self-selected permanent night workers, and studied if the effect of night shifts differed between morning and evening types and compared with 3-shift workers.
METHODS: The study population included 90 permanent night workers followed for 14 days (warehouse workers, 1228 observation days, 80% males). For comparison, we included 70 3-shift workers followed for 26 days (police officers, 1774 observation days, 100% men). Total sleep time (TST), primary sleep duration (PSD), and sleep efficiency were assessed by actigraphy. Measures of sleep quality and diurnal type were self-reported.
RESULTS: Among permanent night workers, TST, PSD, difficulties falling asleep, disturbed sleep, and the number of awakenings decreased after night shifts compared with days without night work. Sleep efficiency, difficulties awakening, and non-refreshing sleep increased. More consecutive night shifts were associated with shorter TST and PSD. Sleep outcomes did not differ by diurnal type. Permanent night workers had fewer awakenings after night shifts than 3-shift workers, but no other differences were observed.
CONCLUSIONS: This study does not provide evidence that supports recommendation of permanent night work to reduce adverse effects of night shifts on sleep. A limited number of consecutive night shifts is recommended to reduce accumulation of sleep debt.
METHODS: The study population included 90 permanent night workers followed for 14 days (warehouse workers, 1228 observation days, 80% males). For comparison, we included 70 3-shift workers followed for 26 days (police officers, 1774 observation days, 100% men). Total sleep time (TST), primary sleep duration (PSD), and sleep efficiency were assessed by actigraphy. Measures of sleep quality and diurnal type were self-reported.
RESULTS: Among permanent night workers, TST, PSD, difficulties falling asleep, disturbed sleep, and the number of awakenings decreased after night shifts compared with days without night work. Sleep efficiency, difficulties awakening, and non-refreshing sleep increased. More consecutive night shifts were associated with shorter TST and PSD. Sleep outcomes did not differ by diurnal type. Permanent night workers had fewer awakenings after night shifts than 3-shift workers, but no other differences were observed.
CONCLUSIONS: This study does not provide evidence that supports recommendation of permanent night work to reduce adverse effects of night shifts on sleep. A limited number of consecutive night shifts is recommended to reduce accumulation of sleep debt.
摘要：
目标：可以想象，与轮班工人相比，永久性夜班工人对夜班工作的昼夜节律适应性更好，因此有更好的可能性在夜班后获得充足的优质睡眠。我们调查了夜班的影响，包括自选的永久性夜班工人的连续轮班次数对睡眠的影响，并研究了夜班的影响是否在早晨和晚上类型之间有所不同，并与三班工人进行了比较。
方法：研究人群包括90名长期夜班工人，随访14天（仓库工人，1228个观察日,80%男性）。为了比较，我们包括70名三班倒工人，他们被跟踪了26天(警察，1774个观察日,100%男性）。总睡眠时间(TST)主要睡眠持续时间（PSD），和睡眠效率通过肌动描记术进行评估。睡眠质量和昼夜类型的测量是自我报告的。
结果：在永久夜班工人中，TST,PSD,入睡困难,睡眠不安,与没有夜班的日子相比，夜班后醒来的次数减少了。睡眠效率,觉醒的困难，和非清爽睡眠增加。更多的连续夜班与更短的TST和PSD相关。睡眠结果因昼夜类型而异。永久夜班工人夜班后的觉醒少于三班工人，但没有观察到其他差异。
结论：本研究未提供支持建议永久性夜班以减少夜班对睡眠的不利影响的证据。建议进行有限数量的连续夜班，以减少睡眠债务的积累。
方法：研究人群包括90名长期夜班工人，随访14天（仓库工人，1228个观察日,80%男性）。为了比较，我们包括70名三班倒工人，他们被跟踪了26天(警察，1774个观察日,100%男性）。总睡眠时间(TST)主要睡眠持续时间（PSD），和睡眠效率通过肌动描记术进行评估。睡眠质量和昼夜类型的测量是自我报告的。
结果：在永久夜班工人中，TST,PSD,入睡困难,睡眠不安,与没有夜班的日子相比，夜班后醒来的次数减少了。睡眠效率,觉醒的困难，和非清爽睡眠增加。更多的连续夜班与更短的TST和PSD相关。睡眠结果因昼夜类型而异。永久夜班工人夜班后的觉醒少于三班工人，但没有观察到其他差异。
结论：本研究未提供支持建议永久性夜班以减少夜班对睡眠的不利影响的证据。建议进行有限数量的连续夜班，以减少睡眠债务的积累。
