0168 Subjective and Objective Markers of Sleepiness in Drivers

Abstract Introduction Sleepiness is associated with a decrease in cognitive abilities with effects comparable to those of alcohol. It remains one of the main causes of fatal road accidents. Various tools are available to assess sleepiness subjectively and objectively, such as questionnaires and multiple sleep latency test. However, the former are subject to intra- and inter-individual variability, and the latter is only feasible in a sleep laboratory. The main objective of this study was to explore new potential markers (biological, neurocognitive) to assess sleepiness in drivers. In this perspective, the easy-to-use BLAST attention test allows the evaluation of micro-fluctuations in vigilance. In addition, salivary markers are good physiological markers, easily accessible and non-invasive to collect. Recent studies have suggested that salivary a-amylase and oxalate may be biomarkers of sleep pressure. Methods 185 drivers (median age 44 years, 72% male, 15% obese) were included during a break at a highway service area, in the morning, while on the road for vacation. Questionnaires on sleepiness, sleep the day before departure, an attention test and two salivary samples (alpha-amylase and oxalate) were taken. Associations between subjective and objective measures of sleepiness, sleep characteristics and salivary concentrations were tested using regression models adjusted for confounding factors. Results The night before departure, 57% of drivers reduced their sleep time and more than ¼ slept 5 hours or less. The higher the number of miles to drive, the shorter the sleep time. 16% of the drivers complained of poor sleep quality and difficulty falling asleep. At the time of the test, 46% of the drivers felt drowsy. Poor sleep quality or difficulty falling asleep the night before departure was associated with increased sleepiness as assessed by the Stanford Sleepiness Scale and decreased attentional ability as assessed by the BLAST. No association between salivary samples and sleepiness was observed. Conclusion Sleep characteristics on the day before departure were associated with sleepiness and attentional performance. The Stanford Sleepiness Scale and the BLAST could be used by individual drivers in a self-evaluation context. Support (If Any) This study was funded by the Vinci Foundation.