Circadian phase response curves to light in older and young women and men.
Circadian phase response curves to light in older and young women and men.
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DOI：
10.1186/1740-3391-5-4
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发表时间：
2007-07-10
影响因子：
--
通讯作者：
Rex KM
中科院分区：
文献类型：
--
作者：
Kripke DF;Elliott JA;Youngstedt SD;Rex KM
昼夜节律的相位反映了峰值和谷值发生的位置，例如，24小时内性能的峰值和谷值。光照可以改变这个阶段。需要更广泛地了解人类对光的昼夜节律相位响应，以指导轮班工作者，航空旅行者和昼夜节律相位紊乱的人的光治疗。这项研究测试了老年人对光（3000勒克斯）没有或较弱的相移反应的假设，女性的反应可能与男性不同。在初步健康筛查和家庭活动记录基线后，50名年轻人（年龄18-31岁）和56名老年人（年龄59-75岁）在光控实验室环境中保持4.7至5.6天，同时经历90分钟的超短睡眠-觉醒周期。在至少30小时的实验室基线后，在接下来的51小时内，参与者接受3次3000勒克斯白色光治疗，每次治疗3小时，以8个时钟时间之一为中心。在基线和治疗后评估尿aMT 6s（褪黑激素代谢物）、游离皮质醇、口腔温度和手腕活动的昼夜节律。光照（3000 lux，持续3小时，持续3天）诱导的最大相移约为3小时。在老年组和青年组之间，或者在女性和男性之间，相移的幅度没有显著差异。在家中和基线时，与年轻人相比，老年人在睡眠、皮质醇和aMT 6s发作方面显著提前，但在aMT 6s峰期或温度节律方面不提前。从延迟到提前的拐点在老年参与者中比年轻参与者早约1.8小时，参考他们的aMT 6s节律峰值，并且在时钟时间上更早。在这些实验条件下，3000勒克斯的光可以改变老年人和年轻人的昼夜节律的相位，但相移的最佳光照时间不同。对于接近下午4点的时间间隔，明亮的光对两个年龄组都只产生了可以忽略的相移。
The phase of a circadian rhythm reflects where the peak and the trough occur, for example, the peak and trough of performance within the 24 h. Light exposure can shift this phase. More extensive knowledge of the human circadian phase response to light is needed to guide light treatment for shiftworkers, air travelers, and people with circadian rhythm phase disorders. This study tested the hypotheses that older adults have absent or weaker phase-shift responses to light (3000 lux), and that women's responses might differ from those of men. After preliminary health screening and home actigraphic recording baselines, 50 young adults (ages 18–31 years) and 56 older adults (ages 59–75 years) remained in light-controlled laboratory surroundings for 4.7 to 5.6 days, while experiencing a 90-min ultra-short sleep-wake cycle. Following at least 30 h in-lab baseline, over the next 51 h, participants were given 3 treatments with 3000 lux white light, each treatment for 3 h, centered at one of 8 clock times. The circadian rhythms of urinary aMT6s (a melatonin metabolite), free cortisol, oral temperature, and wrist activity were assessed at baseline and after treatment. Light (3000 lux for 3 h on 3 days) induced maximal phase shifts of about 3 h. Phase shifts did not differ significantly in amplitude among older and young groups or among women and men. At home and at baseline, compared to the young, the older adults were significantly phase-advanced in sleep, cortisol, and aMT6s onset, but not advanced in aMT6s acrophase or the temperature rhythm. The inflection from delays to advances was approximately 1.8 h earlier among older compared to young participants in reference to their aMT6s rhythm peaks, and it was earlier in clock time. In these experimental conditions, 3000 lux light could shift the phase of circadian rhythms to about the same extent among older and young adults, but the optimal light timing for phase shifting differed. For an interval near 4 PM, bright light produced only negligible phase shifts for either age group.