People who don’t get enough sleep tend to experience a wide variety of health problems, but scientists haven’t known why at a molecular level. Now, Derk-Jan Dijk and colleagues at the University of Surrey in England report changes in gene activity in 26 people who had built up a sleep deficit.
For one week the volunteers slept at least eight hours per night. Then, participants were allowed just under six hours of sleep each night for another week. People were sleepy and sluggish after that week, and blood tests showed that the activity of 711 of their genes had changed, the researchers report online February 25 in the Proceedings of the National Academy of Sciences.
Among the genes affected by the shift were those that govern the immune system. Some of those genes stopped cycling in a daily, or circadian, pattern. Activity of other genes that don’t usually follow the clock fell into a daily rhythm. The researchers conclude that skimping on sleep can drastically change the body’s daily rhythms and may lead to health problems.