Facilitated by the SciLifeLab National Genomics Infrastructure (NGI), researchers have discovered that the blood levels of tau – a biomarker for Alzheimer’s disease – increases when the test subjects were deprived of just one night of sleep.
Tau is a protein found in neurons that can form tangles and accumulate in the brains of people with Alzheimer’s disease. The accumulation can begin decades before symptoms appear. Previous studies have suggested that sleep deprivation can increase the levels of tau in the cerebral spinal fluid while head trauma can increase the tau concentration in the blood.
“Many of us experience sleep deprivation at some point in our lives due to jet lag, pulling an all-nighter to complete a project, or because of shift work, working overnights or inconsistent hours,” says last author Jonathan Cedernaes (UU) in a press release from Uppsala University. “Our exploratory study shows that even in young, healthy individuals, missing one night of sleep results in a slight increase in the level of tau in blood. This suggests that over time, similar types of sleep disruption could potentially have detrimental effects.”
The study, published in the medical journal Neurology, showed that the test subjects, who consisted of young men, had an average 17-percent increase in tau levels in their blood after sleep deprivation compared to the 2-percent increase found after a good night of sleep.
The researchers also investigated the levels of four other biomarkers associated with Alzheimer’s but could not find any increase of those after sleep deprivation.
“It’s important to note that while accumulation of tau in the brain is not good, in the context of sleep loss, we do not know what higher levels of tau in blood represent” said Cedernaes. “When neurons are active, release of tau in the brain is increased. Higher levels in the blood may reflect that these tau proteins are being cleared from the brain or they may reflect an overall elevation of the concentration of tau levels in the brain. Future studies are needed to investigate this further, as well as to determine how long these changes in tau last, and to determine whether changes in tau in blood reflects a mechanism by which recurrent exposure to restricted, disrupted or irregular sleep may increase the risk of dementia. Such studies could provide key insight into whether interventions targeting sleep should begin at an early age to reduce a person’s risk of developing dementia or Alzheimer’s disease.”
Read the full press release here.