这项实验表明，正常睡眠周期与身体对能量的利用有关。研究结果发表在最新一期《生理学杂志》（The Journal of Physiology）上。
研究人员提醒说，虽然缺少睡眠额外消耗的能量看上去不多，但人的身体可能利用睡眠时节约的能量来支持其他一些重要生理过程，比如巩固学习及记忆能力、加强免疫功能、生成和释放激素等。睡眠不足导致的能量损失，可能会使这些生理过程能量供应不足，对健康产生不利影响。 Metabolic Cost of Human Sleep Deprivation Quantified by University of Colorado Team
January 3, 2011
In the first-ever quantification of energy expended by humans during sleep, a University of Colorado team has found that the metabolic cost of an adult missing one night of sleep is the equivalent of walking slightly less than two miles.
The new findings will help researchers further understand one of the important functions of sleep in humans, said CU-Boulder Associate Professor Kenneth Wright. Wright, who led the study, said the goal was to measure and quantify energy expenditure during both sleep and wakeful periods.
"We found that people do expend more energy when they are awake in bed than when they are asleep," he said. The findings showed the eight hours of sleep saved roughly 135 calories over eight hours of wakefulness.
"While the amount of energy savings for humans during sleep may seem relatively small, it actually was a little more than we expected," said Wright, a faculty member in CU-Boulder's integrative physiology department and director of CU-Boulder's Sleep and Chronobiology Laboratory.
A paper on the subject was published in the January issue of the Journal of Physiology. Co-authors included CU-Boulder's Christopher Jung and Emily Frydenall, as well as Assistant Professor Edward Melanson, Dr. Leigh Perreault and Dr. Robert Eckel of the University of Colorado School of Medicine. Jung, first author on the paper, got his doctorate from CU-Boulder in 2009 and is now at the University of Alaska.
The study showed that compared to a typical night of sleep, the amount of energy expended by study subjects during 24 hours of sleep deprivation was up about 7 percent. In contrast, energy expenditure decreased by about 5 percent during the recovery episode, which included 16 hours of wakefulness following the sleep deprivation night, then eight hours of recovery sleep, Wright said.
"Understanding the function of sleep, especially in humans, is considered one of the most important scientific enigmas," said Wright, who also is an adjunct faculty member at the University of Colorado School of Medicine.
The study, which included seven young adult subjects, was tightly controlled. All participants were required to stay in bed for the entire three-day study. Their diets met individual daily energy requirements, and the content and timing of each meal was exactly at the same time each day during the lab study. The subjects spent the sleep deprivation night in bed watching movies, reading and talking, said Wright.
The first day of the study consisted of a typical 16 hours of wakefulness followed by eight hours of sleep. Days two and three included 40 hours of total sleep deprivation followed by eight hours of recovery sleep.
As part of the study, the researchers studied the effects of sleep stages ranging from light sleep to rapid-eye movement sleep to deep, "slow wave" sleep and awakenings from sleep on whole body energy expenditure, Wright said. The study indicated the most energy was expended during natural arousals from sleep, which occurred less often during the eight-hour sleep episodes following sleep deprivation.
The amount of energy saved during sleep by the study subjects likely would have been higher if they were allowed to continue sleeping after the eight hours of recovery sleep rather than being awakened, which was the final step in the study, said Wright.
作者:admin@医学,生命科学 2011-01-24 00:02