A cross-sectional study on the associations of sleep-disordered breathing with subjective and objective sleepiness among local police officers

Abstract

Introduction It is indicated that Sleep-Disordered Breathing (SDB) increase the risk of motor vehicle crashes and injuries because of their daytime sleepiness. However, to date the potential SDB without daytime sleepiness also increase the risk of accidents. Therefore, not only the subjective sleepiness but also the objective sleepiness are needed to measure for the detection of SDB. The aim of this study was to examine the associations of severity of SDB with subjective sleepiness by Epworth Sleepiness Scale (ESS) and objective sleepiness by Psychomotor Vigilance Test (PVT). Materials and methods Among police officers who usually drive by their work, 928 men aged 22–59 years [mean age was 41.4 years] were tested by ESS questionnaire and 10 min PVT and were measured blood oxygen saturation level using pulse-oximeters during night. In PVT, participants were compelled to push buttons right after increasing number was displayed, and they were estimated objective sleepiness by reaction time. We selected three indicators in this study; Fastest 10% RT, Mean 1/RT and Slowest 10% 1/RT. Data was divided into three groups by 3% oxygen desaturation index (3%ODI)[ Results We calculated age-adjusted mean values of subjective and objective sleepiness indicators for each 3% ODI groups [ p for trend = 0.02)], Fastest 10% RT[195.3, 196.2, 198.5 ( p for trend = 0.05)], Mean 1/RT[4.28, 4.22, 4.18 ( p for trend = 0.02)], Slowest 10% 1/RT [3.01, 2.93, 2.87 ( p for trend = 0.01)]. Additionally we also compared the Receiver Operating Characteristic Curves of ESS with those of each PVT indicator for severe or moderate SDB (3%ODI ⩾15), and then each PVT indicator were more evident but non-significant difference from ESS ( p Conclusion Our study showed that the severity of SDB is positively associated with subjective and objective sleepiness indicators, but relationship of SDB with objective sleepiness is tend to be more evident than with subjective sleepiness. Acknowledgement We are grateful to Dr. Yasuhiko Tanno for his technical assistance.