Blood-based biomarker can detect sleep deprivation

Lack of sleep is known to increase the risk of serious injury or fatality in safety-critical situations. Now, a research team led by Monash University has developed a metabolomic biomarker that can indicate when someone has not slept for 24 hours.

Described in the journal Science Advances, the biomarker used a combination of markers found in the blood of healthy young volunteers. Together, these markers accurately predicted when the study volunteers had been awake for more than 24 hours under controlled laboratory conditions.

The biomarker detected whether individuals had been awake for 24 hours with a 99.2% probability of being correct, when compared to their own well-rested sample. When a single sample was considered without the well-rested comparison (similar to a diagnostic blood test), it dropped to 89.1%, which was still considered very high.

“This is a really exciting discovery for sleep scientists, and could be transformative to the future management of health and safety relating to insufficient sleep,” said senior author Professor Clare Anderson, who led the research while she was with the Monash University School of Psychological Sciences and Turner Institute for Brain and Mental Health.

“There is strong evidence that less than five hours’ sleep is associated with unsafe driving, but driving after 24 hours awake, which is what we detected here, would be at least comparable to more than double the Australian legal limit of alcohol performance-wise.”

With about 20% of Australia’s road accidents caused by sleep deprivation, the researchers hope their discovery may inform future tests to quickly and simply identify sleep-deprived drivers. Their test may be also useful for future forensic use, though further validation is required.

“Next steps would be to test it in a less controlled environment and maybe under forensic conditions, particularly if it was to be used as evidence for crashes involving drivers falling asleep,” said first author Dr Katy Jeppe, from the Monash Proteomics and Metabolomics Platform (previously from the School of Psychological Sciences).

“Given it’s blood, the test is more limited in a roadside context, but future work could examine whether our metabolites, and therefore the biomarker, are evident in saliva or breath.”

While the sleep deprivation biomarker is based on 24 hours or more awake, it can detect down to 18 hours awake. A biomarker for limited sleep over the previous night could also be developed — with other researchers having made progress in this respect, according to Jeppe — but more research is required to combine the time since sleep with the amount of sleep in the predictions.

The test could also be developed for other situations where sleep deprivation may lead to catastrophic consequences, such as in safety-critical workplaces. The Chernobyl nuclear reactor meltdown and the Challenger space shuttle disaster are both thought to be caused, in part, by human error associated with fatigue.

“Objective tests that identify individuals who present as a risk to themselves or others are urgently needed in situations where the cost of a mistake is fatal,” Anderson said.

“Alcohol testing was a game changer for reducing road crashes and associated serious injuries and fatalities, and it is possible that we can achieve the same with fatigue. But much work is still required to meet this goal.”

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