Circadian rhythm of preoperative period and effects of bright light on physiological activity

对手术患者进行睡眠-觉醒节律测定，12例患者平均睡眠时间(22：00~6：00)；术前第3天(POD3)400min，POD2 400min，术前395min，手术当天367min，术后第1天(POD1)307min，POD2 284min，POD3 290min，POD4 263min，POD5 282min。第1天白天用荧光灯提供强光，第2天用弱光照射。比较白天暴露于强光和暗光后睡眠期间的平均值。在每日强光照射后23：30~02：00 h，HF成分显著增加，并伴有心率减慢。结果表明，白天的强光暴露可以增强午夜前后的副交感神经活动。白天的暗光或强光暴露对人类胃肠活动的影响。我们使用呼气氢(指示碳水化合物吸收不良)和胃电(胃电，指示胃肌电活动)测试来测量胃肠活动。餐后呼气氢排泄量在白天弱光条件下的第二个夜间期间显着高于强光条件下。在昏暗条件下，受试者进餐后所记录的频谱总功率显着低于强光条件下的受试者。这些结果表明，白天的暗光暴露会抑制晚餐的消化，导致膳食中碳水化合物的吸收不良。

Measurement of sleep-wake rhythm was carried out in the surgical patients by actigraphy.Mean sleep time (22:00 to 6:00) of 12 patients was following; 400 min at preoperative day 3(POD 3), 400min at POD 2 and 395 min at preoperative, 367 min at operative day, 307 min at post operative day 1 (POD 1), 284 min at POD2, 290 min at POD 3, 263 min at POD 4, and 282 min at POD 5.Bright light exposure during daytime increases parasympathetic nerve activity during the nighttime.A spectral analysis of heart rate was carried out on 11 young female adults in order to evaluate the effects of bright light exposure on autonomic nervous activity. Bright light was provided by fluorescent lamps during the daytime on day 1. Dim light was given on day 2. The average value during the sleep period was compared following diurnal exposure to bright or dim light. HF component was significantly greater from 23:30 h to 02:00 h after diumal exposure of bright light, being accompanied by lower heart rate during these periods. The results indicate that bright light exposure during the daytime could enhance parasympathetic activity around midnight.Effects of dim or bright-light exposure during the daytime on human gastrointestinal activity.We measured gastrointestinal activity using a breath hydrogen (indicative of carbohydrate malabsorption) and an electrogastrography (EGG, indicative of gastric myoelectric activity) test. Postprandial breath hydrogen excretion during the following nighttime period after daytime exposure to the dim-light condition was significantly higher than under the bright-light condition. The spectrum total power of the EGG recorded after taking the evening meal was significantly lower for the dim than bright-light condition. These results indicate that dim-light exposure during the daytime suppresses the digestion of the evening meal, resulting in malabsorption of dietary carbohydrates in it.