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That long winter's 'nap' may be a killer
October 4, 2011
Dr. Shawn Youngstedt has received a grant
from NIH to study the health effects of sleeping
eight hours or more.
With so much hype these days about the dangers of not getting enough sleep, it is less well recognized that long sleep might be just as hazardous. Just as people get too much of other healthy things like sunlight and calories, it seems that people can also get too much sleep.
Dr. Shawn Youngstedt of the Arnold School of Public Health, a sleep researcher, has received a prestigious RO1 grant from the National Institutes of Health to study long sleep and its effects in older adults, 60 – 80 years of age. The five-year, $3.7 million grant also will involve research sites at the University of Arizona, UCLA and the State University of New York-Downstate.
"People are skeptical that long sleep is truly hazardous," said Youngstedt, an associate professor in the Department of Exercise Science and the study's principal investigator. "But, there are now over 100 studies that show that sleeping eight or more hours per night is associated with mortality, heart disease, diabetes, obesity, and inflammation, some of which have controlled for over 30 factors."
The study will examine whether sleep restriction in this group will have any negative effects, he said. "Having a slight decrease in the amount of sleep might actually be helpful over time," he said. "This hasn't been studied before."
The study will assess 200 people, 100 of whom will be people between 60-80 years of age who sleep eight – nine hours per night. The other 100 people will be 60 – 80-year-old people who sleep between 6 and 7¼ hours per night. The researchers will reduce the amount of time the subjects spend in bed by one hour every night for 12 weeks. The impact of reduced sleep will be determined by measures such as a lipid profile, measures of inflammation, glucose tolerance, quality of life, sleepiness, mood, and performance on reaction-time tests. Participants will wear an ActiGraph, which resembles a watch and estimates sleep.
There is a lot of evidence that sleep deprivation can be harmful, but this evidence has been found in studies involving extreme amounts of sleep loss (24-72 hours) over a very short time. Other evidence suggest that people can well-tolerate moderate sleep restriction maintained over a long time. For the study that Youngstedt and colleagues are just starting, it is possible that the one-hour restriction of time in bed might actually be beneficial for the subjects. The subjects will be older adults who often have very fragmented sleep. Spending less time in bed can help consolidate sleep, which could make people sleep more soundly and could have other health benefits. The long sleepers might especially benefit.
The research team expects to start recruiting by October 2011. If interested in performing in the Multi-Site Sleep Study, please contact Dr. Youngstedt at 803-777-9929, syoungstedt@sc.edu.
