Are you one of those people who can pull an all-nighter and give the best presentation of your life at work the next day?
Or does missing just a few hours of sleep turn you into an incoherent zombie with a super-craving for triple shots of espresso?
It’s not a myth that some people “have it” when it comes to functioning on low sleep. Research shows that lack of sleep affects people differently — both mentally and at the molecular level.
Researchers are using this natural variation to find biomarkers that can help identify people most at risk of the negative effects of not getting enough sleep.
Lack of sleep affects mental abilities
One of these biomarker studies was presented earlier this month at the SLEEP 2018 meeting in Baltimore.
Researchers found that people who went without sleep for 39 hours showed altered levels of certain microRNAs (miRNAs) in the blood. These molecular changes also predicted how much sleep loss negatively affected cognitive performance.
MiRNAs molecules are small bits of genetic material that regulate gene expression. They typically work by preventing messenger RNAs from turning the information stored in genes into functional proteins.
The study included 32 healthy adults who were monitored for five days — two nights of 8 hours of sleep followed by 39 hours of no sleep at all. This is known as total sleep deprivation, or the more popular “all-nighter.”
Afterwards, people had two nights of recovery, with 8 to 10 hours of sleep each night.
Researchers measured miRNA levels using blood samples. They also tested several types of cognitive abilities, including attention, memory, and cognitive throughput performance (how fast and accurately people completed the tests).
Study author Namni Goel, PhD, an associate professor of psychology in the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, said these findings could help predict who’d be most affected by sleep deprivation.
“If you wanted to know how you’d respond [to sleep deprivation] and we were able to tell you that ahead of time, then you could employ countermeasures,” said Goel.
This might mean having an extra cup of coffee or taking a nap if you know you’re not going to get enough sleep.
This is especially important if your job or lifestyle depends on thinking clearly — such as pilots, truck drivers, first responders, healthcare professionals, and other people who work long shifts or at night.
Cat naps and caffeine, though, are only temporary fixes. “There’s no substitute for sleep,” said Goel.
The current study followed people who stayed up for 39 hours. But similar effects would happen if you were chronically sleep-deprived for enough nights.
Goel said that pulling an all-nighter and sleeping only four hours a night for five days in a row are “comparable” in terms of the cognitive deficits that you see.
Identifying people who are sleep-deprived
Dr. Brandon Peters, a neurologist and sleep medicine specialist at Virginia Mason Medical Center in Seattle, said this line of research also “gives us a new way to objectively measure the effects of either sleep deprivation or poor-quality sleep.”
One way to assess how much lack of sleep affects someone is to ask them.
But Peters, who wasn’t involved in the study, said it’s “extremely difficult” for people to know how much they’re affected by sleep deprivation. They’ll often say they’re doing well when they really aren’t.
Experts can also test their cognitive abilities, like the researchers did in the current study. This type of testing, though, is time-intensive.
That’s what makes biomarkers so attractive.
“Blood tests would be something rather simple to do,” said Peters. “You could have some blood drawn to get a better sense of how impaired you might be.”
Biomarker testing could also help doctors identify people who aren’t getting enough sleep.
“It would be helpful to have something that could provide guidance in whether or not an individual is meeting their own sleep needs at that point in their life,” said Peters.
He added that having an objective measure of sleep deprivation might also encourage people to make sure they’re getting enough sleep each night.
In case you’re wondering how much that is, the National Sleep Foundation recommends seven to nine hours for most adults.
More research is needed before this can be used in the clinic. Goel said her team wants to look at how different types of sleep loss affect miRNA levels and cognitive abilities.
Peters said that there’s a lot of interest in developing new technologies that “better measure the effects of sleep deprivation,” especially ones that motivate us to get enough sleep.
Who knows, maybe someday there will be a wearable device connected to your smartphone that alerts you when the miRNAs in your blood indicate that you need more sleep.