Sleep Away the Pain

Pain sensitivity reduced when sleep time is increased in healthy individuals

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Wouldn't it be nice to spend an extra few hours in bed each morning? Chances are, you would get all the sleep you need - and you may feel less pain during the day.

That's what a recent small study found during an experiment on pain and extra sleep. When healthy volunteers were given more time in bed, they felt less sensitivity to pain.

"Get at least 8 hours of sleep nightly."

The study, led by Timothy A. Roehrs, PhD, from the Sleep Disorders and Research Center of Henry Ford Hospital in Detroit, aimed to find out whether extra time in bed might decrease a person's sensitivity to pain. The study was very small, with just 18 healthy individuals who took an average of less than 8 minutes to fall asleep on a typical day. The volunteers were randomly assigned to one of two groups.

One group was given four nights of extra bedtime in which they remained in bed for 10 hours. The other group spent four nights with the same sleep and bedtime schedule they normally kept.

On the first and fourth nights of the study, all the participants were tested to see how long it took them to fall asleep at four different times during the day (10 am, 12 pm, 2 pm and 4 pm). This is a common assessment used to determine a person's level of sleepiness. The participants were also given a pain sensitivity test twice during the day in which a laser focused on their finger increases in heat intensity until they pull away their finger.

The group that was given extra time in bed slept an average of 1.8 hours more each night than those following their regular schedule. They also took longer to fall asleep during the four assessments, which means they were less sleepy than the individuals following their normal schedule.

The group who received extra bedtime also took longer to pull their fingers away during the pain sensitivity test. This means they had a higher threshold for the pain than those following their regular sleep and bedtime schedule.

When the researchers analyzed the results of the various assessments, they found that the amount of extra time individuals got to sleep corresponded to their reduced level of sleepiness and to their reduced sensitivity to pain.

The researchers concluded that mildly sleepy but otherwise healthy adults appear to feel less pain when they are given extra time in bed. More time in bed also leads them to get more sleep and to be less sleepy during the day.

William Kohler, MD, the director of the Florida Sleep Institute in Spring Hill Florida and a dailyRx contributing expert, said this article confirms the findings of past studies that sleepiness and pain sensitivity are correlated.

"Even though this study is relatively small, it showed that the reversal of the mild sleep loss improved pain sensitivity," Dr. Kohler said. "They showed that reducing the poor sleep time increased benefit by reducing the pain sensitivity."

The study was published in the December issue of the journal Sleep. The research was funded by the Fund for Henry Ford Health System. One author is an employee at Harvard Medical School's Department of Health Care Policy, which has received research funds from four pharmaceutical companies. Another author served as a consultant for two pharmaceutical companies, and a third has consulted for over two dozen pharmaceutical companies. The other authors declared no conflicts of interest.

Reviewed by: 
Review Date: 
December 4, 2012
Last Updated:
December 14, 2012