Estimating that people sleep on average up to two hours less over the last decades, sleepiness and fatigue need to be considered as significant societal problems of the modern world. Jurisdiction is precise on how to deal with overtired offenders since they were not allowed to use machines or vehicles in the first place, similar to drunk individuals or consumers of illicit drugs. In contrast to alcohol or illicit drug use, however, there are no quick roadside or workplace tests as objective (analytical) biomarkers for sleepiness.

Investigators hypothesize that increasing sleep drive or impaired wakefulness can be assessed by qualitative or quantitative fluctuations of certain metabolites in biological specimens, e.g., accumulation or decrease of endogenous substances related to sleep debt. Thus, this sleep study provides the necessary biological samples of either sleep-deprived, sleep-restricted, or control subjects, which are then analysed for appropriate metabolite biomarkers utilizing an untargeted metabolomics approach. In addition to established impairment tests, a state of the art driving simulator will be employed to objectively measure driving performance under all study conditions. Participants will also rate their subjective sleepiness using validated questionnaires.

Inclusion Criteria:

• understanding and spoken command of German language
• good health condition
• Body Mass Index between 18.5-24.9 kg/m2
• habitual average sleep duration between 7-9 hours / night
• habitual consumption of 3 or fewer caffeinated beverages / day
• habitual consumption of 5 or fewer alcoholic beverages / week
• good sleep quality: Pittsburgh Sleep Quality Index score ≤ 5
• reasonable oral hygiene (≥1 tooth brushing / day)
• normal or corrected-to-normal vision
• car driving license holder since at least 2 years (obtained in a country with right hand traffic) and regular driver (≥ 1 per week)

Exclusion Criteria:

• two or more time zone crossings in the last 3 months
• habitual napper
• history or presence of neurological disorder, psychiatric disorder, cardiovascular disorder, dental disorder or any disorder that could pose a risk in participating or that could possibly influence study measurements
• history or presence of a sleep disorder (screening night)
• use of illicit drugs (urinary drug screening)
• use of current medication (urinary drug screening) known to influence study measurements
• extreme chronotype (reduced Morningness-Eveningness-Questionnaire score ≤7 or ≥22)
• current smoker
• habitual use of energy drinks (>1 / week)
• severe skin allergies or hypersensitivities
• food allergies
• hospital stay in past 6 months
• shift worker, night worker
• recent past (last 3 months) or present Covid-19 infection
• fainting at the sight of blood or needles
• participation in a clinical study less than 30 days ago or is currently participating in other clinical studies
• simulator sickness syndrome
• refusal to sign informed consent

Results will be published in peer-reviewed journals. Anonymized raw data will be made available upon request.

starting after publication

upon request via e-mail