Lack of sleep is just as dangerous as excessive drinking when it comes to activities such as driving. The breathalyzer can reliably measure a person's state of intoxication, but there's currently no way of assessing someone's tiredness. New research may soon change that, however.
"[S]tarving the body of sleep also robs neurons of the ability to function properly," the study's senior author noted.
Lack of sleep can be dangerous when it comes to driving — as well as a huge obstacle in the way of productivity — but we don't have an objective way of assessing it.
Recently, however, scientists at the Sleep Research Centre at the University of Surrey in the United Kingdom have been developing a blood test that would enable them to evaluate biomarkers of sleep deprivation.
"We all know," says study co-author Dr. Emma Laing, "that insufficient sleep poses a significant risk to our physical and mental health, particularly over a period of time."
"However," she adds, "it is difficult to independently assess how much sleep a person has had, making it difficult for the police to know if drivers were fit to drive, or for employers to know if staff are fit for work."
This prototypical test, the researchers report in the study paper published in the journal Sleep, could eventually be built upon and developed into an assessment of chronic sleep loss.
'First step' to chronic sleeplessness test
The scientists, led by Prof. Derk-Jan Dijk, worked with 36 participants, all of whom skipped 1 night's sleep. Thus, the volunteers stayed awake for 40 hours straight, during which time they also provided blood samples for the scientists.
Prof. Dijk and his colleagues analyzed changes in the expression levels of many sets of genes in these blood samples by applying a machine learning algorithm.
This way, they identified 68 genes whose expression was affected by lack of sleep. They were able to find out with 92 percent accuracy whether the blood samples came from a person who was sleep deprived or who, to the contrary, had had enough rest.
"Identifying these biomarkers is the first step to developing a test which can accurately calculate how much sleep an individual has had."
Study co-author Prof. Simon Archer
"The very existence of such biomarkers in the blood after only a period of 24-hour wakefulness," he adds, "shows the physiological impact a lack of sleep can have on our body."
In the United States, drowsy driving is "responsible for 72,000 crashes, 44,000 injuries, and 800 deaths in 2013" alone, the Centers for Disease Control and Prevention (CDC) report.
Furthermore, the National Safety Council have found that about 43 percent of people in the U.S. do not get enough sleep, and that 76 percent have declared that they feel tired at work.
In the future, the researchers hope that they will be able to develop a further blood test that would facilitate the assessment of chronic sleep deprivation — that is, insufficient sleep over a longer period of time.
"This is a test for acute [1 night's] total sleep loss; the next step is to identify biomarkers for chronic insufficient sleep, which we know to be associated with adverse health outcomes," says Prof. Dijk.