Researchers from the Institute of Forensic Medicine and the Institute of Pharmacology and Toxicology at the University of Zurich searched for direct metabolic markers of sleep deprivation in saliva. Until now, sleep loss could not be measured objectively in bodily fluids. The team tested whether a single saliva sample can reveal acute sleep deprivation under realistic conditions.
Twenty healthy young men who normally sleep seven to nine hours completed three experimental conditions in random order: one night without sleep, four consecutive nights of six hours' sleep, and a control condition with eight hours. The researchers analysed saliva using high-resolution mass spectrometry and applied machine-learning methods to screen tens of thousands of molecules for patterns linked to acute sleep loss.
They report that acute sleep deprivation affects about 10% of all biomolecules in saliva and identified ten biomarkers that reliably indicate fatigue. The patented biomarker set will be validated in a large international field study under realistic conditions. The field tests will include common real-life factors such as shift work, alcohol and medications. In the long term, the work could lead to a rapid on-site test to detect fatigue and so improve road and workplace safety. The study appears in the Journal of Proteome Research.
Difficult words
- metabolic marker — substance that shows changes in body chemistrymetabolic markers
- saliva — clear liquid produced in the mouth
- acute — sudden and short in time or intensity
- biomolecule — molecule that is part of living organismsbiomolecules
- biomarker — measurable biological sign of a conditionbiomarkers
- high-resolution mass spectrometry — laboratory technique that measures molecules precisely
- machine-learning — computer methods that find patterns in data
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- How could an on-site saliva test for fatigue improve road and workplace safety? Give specific examples.
- Which real-life factors should be included when validating the biomarker set, and why are they important?
- What ethical or practical challenges might arise if employers used saliva fatigue tests at work?
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