Härmä M I, Hakola T, Akerstedt T, Laitinen J T
Institute of Occupational Health, Department of Physiology, Helsinki, Finland.
Occup Environ Med. 1994 Aug;51(8):568-73. doi: 10.1136/oem.51.8.568.
The study was designed to examine the effects of age on sleep and the circadian rhythms during consecutive night shifts.
Two groups of letter sorters (19-29 (n = 7) and 53-59 (n = 7) years of age were studied in a sleep laboratory under closely controlled conditions. After two baseline days, circadian adjustment to three night shifts was monitored by continuous measurement of rectal temperature, salivary melatonin, and sleep-wakefulness during the night shifts.
Age was significantly related to the adjustment to night work of rectal temperature minimum and of self rated sleepiness. Young subjects delayed their temperature phase and decreased sleepiness more than the older subjects. Age was also significantly related to an increase of alertness and to the feeling of being refreshed after the day sleep. Although there were basic differences in sleep duration and structure between the age groups, the latter did not change across the night shifts.
Aging decreases the ability to recover after several, but not after the first night shift.
本研究旨在探讨年龄对连续夜班期间睡眠及昼夜节律的影响。
两组信件分拣员（年龄分别为19 - 29岁（n = 7）和53 - 59岁（n = 7））在睡眠实验室的严格控制条件下进行研究。经过两天的基线期后，通过连续测量直肠温度、唾液褪黑素以及夜班期间的睡眠 - 觉醒情况，监测对三个夜班的昼夜节律调整。
年龄与直肠温度最低点的夜班调整以及自我评定的嗜睡程度显著相关。年轻受试者比年长受试者延迟了体温相位且嗜睡程度降低更多。年龄还与警觉性增加以及日间睡眠后恢复精神的感觉显著相关。尽管不同年龄组在睡眠时间和结构上存在基本差异，但这些差异在夜班期间并未改变。
衰老会降低在连续多个夜班后（而非第一个夜班后）的恢复能力。
