Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sleeping in on the weekends doesn't fix all the deficits caused by workweek sleep loss

10.10.2013
Article published in the American Journal of Physiology-Endocrinology and Metabolism

In many modern societies, adults often sacrifice sleep during the workweek to make time for other demands, then snooze longer on the weekends to recoup that lost sleep.

Research has shown that even a few days of lost sleep can have adverse effects, including increased daytime sleepiness, worsened daytime performance, an increase in molecules that are a sign of inflammation in the body, and impaired blood sugar regulation. These last two could be partially responsible for why sleeping less negatively affects health in other ways and shortens the lifespan.

Though many people believe they can make up sleep lost during the workweek by sleeping more on the weekend, it's unknown whether this "recovery" sleep can adequately reverse these adverse effects.

To help answer this question, researchers led by Alexandros N. Vgontzas of the Penn State University College of Medicine, placed 30 volunteers on a sleep schedule that mimicked a sleep-restricted workweek followed by a weekend with extra recovery sleep. At various points along this schedule, the researchers assessed the volunteers' health and performance using a variety of different tests.

The researchers found that the volunteers' sleepiness increased significantly after sleep restriction, but returned to baseline after recovery sleep. Levels of a molecule in blood that's a marker for the amount of inflammation present in the body increased significantly during sleep restriction, but returned to normal after recovery. Levels of a hormone that's a marker of stress didn't change during sleep restriction, but were significantly lower after recovery. However, the volunteers' measures on a performance test that assessed their ability to pay attention deteriorated significantly after sleep restriction and did not improve after recovery. This last result suggests that recovery sleep over just a single weekend may not reverse all the effects of sleep lost during the workweek.

The study is entitled "The Effects of Recovery Sleep After One Workweek of Mild Sleep Restriction on Interleukin-6 and Cortisol Secretion and Daytime Sleepiness and Performance." It appears in the American Journal of Physiology-Endocrinology and Metabolism, published by the American Physiological Society. The article is available online at http://bit.ly/17TeQgg.

Methodology

The researchers recruited 30 healthy adults who were normal sleepers and put them on a 13-day schedule that involved spending nights in a sleep lab. For the first four nights, the subjects were allowed to sleep for 8 hours, setting a baseline for a healthy, normal amount of sleep. For the next six nights, the researchers woke the subjects up 2 hours earlier. For the following three nights, the subjects were allowed to sleep for 10 hours. The researchers monitored the volunteers' brain waves during these sleep sessions. At three points during the 13-day schedule, the volunteers spent whole days at the lab taking part in various tests: after the 4 days of baseline sleep, after 5 days of restricted sleep, and after 2 days of recovery sleep. On these days, the subjects had catheters inserted into their arms, and the researchers sampled blood every hour, testing it for levels of interleukin-6 (a marker of inflammation) and cortisol (a hormone secreted during stress). They also participated in a test of how quickly they fell asleep when allowed to nap several times during those days (an objective measure of sleepiness) and filled out questionnaires to assess how sleepy they felt (a subjective measure of sleepiness). To assess their performance, they participated in a test in which they were asked to press a button whenever a dot appeared on a screen, which measured how well they were able to pay attention.

Results

Not surprisingly, the researchers found that after 5 days of restricted sleep, the subjects were significantly sleepier on both objective and subjective tests compared to baseline levels. Their interleukin-6 levels increased sharply during restricted sleep, though their cortisol levels remained the same. Their performance on the attention test deteriorated. After 2 days of recovery sleep, both objective and subjective tests showed that the volunteers were less sleepy. Their interleukin-6 levels reduced, and their cortisol levels decreased significantly compared to baseline, possibly suggesting that the volunteers were sleep deprived before the study started. Notably, their performance on the attention test didn't improve after recovery sleep.

Importance of the Findings

Though many indicators of health and well being improved after recovery sleep, these findings suggest that extra sleep may not fix all the deficits caused by lost sleep during the workweek.

"Two nights of extended recovery sleep may not be sufficient to overcome behavioral alertness deficits resulting from mild sleep restriction," the authors write. "This may have important implications for people with safety-critical professions, such as health-care workers, as well as transportation system employees (drivers, pilots, etc.)."

The authors also suggest that even though these results provide some insight on the health effects of a single week of sleep loss and recovery, reliving the cycle over and over again may have more significant health effects that this study wouldn't show.

"The long-term effects of a repeated sleep restriction/sleep recovery weekly cycle in human remains unknown," they write.

Study Team

In addition to Dr. Vgontzas, the study was conducted by Slobodanka Pejovic, Ilia Kritikou, Michele L. Shaffer, and Edward O. Bixler of Pennsylvania State University, Maria Basta of Pennsylvania State University and the University of Crete, Marina Tsaoussooglou and George P. Chrousos of National and Kapodistrian University of Athens, David Stiffler of Pennsylvania State University and the New York School of Medicine, and Zacharias Stefanakis of the University of Crete.

Physiology is the study of how molecules, cells, tissues, and organs function in health and disease. Established in 1887, the American Physiological Society (APS) was the first US society in the biomedical sciences field. The Society represents more than 11,000 members and publishes 14 peer-reviewed journals with a worldwide readership.

NOTE TO EDITORS: To schedule an interview with a member of the research team, please contact Donna Krupa at dkrupa@the-aps.org, @Phyziochick, or 301.634.7209. The article is available online at http://bit.ly/17TeQgg.

Donna Krupa | EurekAlert!
Further information:
http://www.the-aps.org

More articles from Studies and Analyses:

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

nachricht Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>