Sleeping with light turned out to increase the risk of diabetes. The study was found at Northwestern University, USA.
In this study, researchers recruited 20 healthy adult volunteers in the age range 18-40 years. The volunteers spent two nights of their three days in the laboratory.
Launched Reader's Digest, Tuesday (06/19/2010), on the first night, they sleep in a dark darkness. The second night, half of them slept in the dark, while the rest slept with bright lights.
Researchers then saw the vital signs of volunteers, brainwave activity, and movement of the feet and eyes. They also take blood samples per hour to measure melatonin, a vital hormone that helps circadian rhythms normally increase during sleep.
Meanwhile, in the morning the researchers conducted a glucose tolerance test on volunteers.
In a study published in the journal Sleep, sleeping under the light was found to encourage insulin resistance, a risk factor for diabetes.
"Our preliminary findings suggest that one night of light exposure during sleep affects the measurement of insulin resistance," said lead author Ivy Cheung Mason, PhD, a colleague at Northwestern's Feinberg School of Medicine in a press release.
Previous studies linked poor sleep to higher risk of depression, breast cancer, and prostate.
Currently, metabolic diseases such as diabetes seem to have been added to the list.
"Sleep disturbance affects more than 25 percent of the general population and up to 50 percent in older adults," says Mason.
Although this is a preliminary study, it supports the idea that you should avoid sleeping on the couch, or letting the television and lights go on during sleep.