June 4 (UPI) -- The way that a person is affected by sleep loss is based on gene expression, according to a new study.
Researchers at the Perelman School of Medicine at the University of Pennsylvania studied the cognitive effects of sleep-deprived people and found differences were reflected in microRNAs. Their findings were presented at the 32nd Annual Meeting of the Associated Professional Sleep Societies LLC in Baltimore.
"These findings show for the first time that miRNAs can track responses to total sleep deprivation and its detrimental combination with psychological stress and predict robust individual differences in various types of cognitive performance," senior author Dr. Namni Goel, an associate professor of psychiatry at Penn, said in a press release.
The study showed that these biomarkers in the blood are changed by total sleep deprivation for 39 hours, as well as by psychological stress.
Goel said miRNAs "can be used to identify individuals ahead of time who are in need of countermeasures or interventions such as caffeine or naps to mitigate or prevent impairments associated with insufficient sleep."
MiRNAs, which are small non-coding RNAs, guide information in a gene to be made into a functional protein. Typically, miRNAs repress expression of their target messenger RNAs, which prevents translation into proteins.
Thirty-two healthy adults between the ages 27 and 53 participated in a five-day experiment of two, 8-hour nights, followed by 39 hours of total sleep deprivation, and then followed by two more 8-to-10-hour recovery nights.
Throughout the experiment, participants underwent testing for attention, memory and cognitive throughput, including the speed and accuracy with which the brain performs in cognitive testing. Blood samples were also taken at six time points during the study, with researchers analyzing plasma for miRNAs.
Compared with the pre-study time point, 10 miRNAs changed in those who were only sleep deprived, compared with 18 miRNAs when they experienced no sleep and psychological stress.
The blood samples taken before the study reflected 14 miRNAs reliably predicted behavioral attention performance during sleep deprivation, seven miRNAs reliably predicted cognitive effects during no sleep and 10 miRNAs reliably predicted memory performance.