Sleep-Disordered Breathing and Quality of Life of Railway Drivers in Greece* Evangelia Nena, MD; Venetia Tsara, MD; Paschalis Steiropoulos, MD; Theodoros Constantinidis, MD; Zoe Katsarou, MD; Pandora Christaki, MD, FCCP; and Demosthenes Bouros, MD, FCCP Background: Sleep-disordered breathing (SDB) and especially obstructive sleep apnea (OSA) are associated with daytime sleepiness and an increased risk for motor vehicle crashes. Previous studies have assessed the prevalence of OSA among professional drivers, but no study so far has focused on railway drivers. The aim of this study was to assess the prevalence of SDB among Greek railway drivers, and correlate it with daytime sleepiness, quality of life, and symptoms. Methods: The following three different questionnaires were anonymously answered by 226 train drivers: a general questionnaire on their demographics and sleep habits; the Greek version of the Epworth sleepiness scale (ESS); and the Medical Outcomes Study 36-item short form (SF-36). Of the 226 drivers, 50 underwent a sleep study, a physical examination, and an assessment of their respiratory function. Results: Participants were all men, had a mean ( SD) age of 46.9  3.9 years, were overweight (mean body mass index [BMI], 28.7  3.7 kg/m 2 ), and were smokers (59.7%). Snoring was reported by 69.9% of them, and apneas by 11.5%. The mean ESS score was 5.4  3.2. SF-36 scores were similar to those of the Greek population. The mean apnea-hypopnea index (AHI) was 11  14 events per hour, and the mean pulse oximetric saturation was 93.2  2.5%. According to AHI severity, they were divided into the following three groups: group 1, normal breathing function in sleep (n  19; AHI, < 5 events per hour); group 2, mild OSA (n  20; AHI, 5.1 to 15 events per hour); group 3, moderate/severe OSA (n  11; AHI, > 15 events per hour). The three groups differed in terms of BMI, and neck, waist, and hip circumferences. No difference was detected, though, in ESS and SF-36 scores. Conclusion: The majority of the Greek railway drivers are overweight and smokers. The most common reported symptom in the questionnaires is snoring, without significant daytime impair- ment, while sleep studies show a potentially higher prevalence of OSA. Trial registration: Democritus University of Thrace Identifier: 2979/5–2003. Trial registration: Union of the Greek Railway Drivers Identifier: 536/10 –2003. (CHEST 2008; 134:79 – 86) Key words: obstructive sleep apnea; professional drivers; quality of life; sleep apnea; sleep-disordered breathing; sleepiness; snoring Abbreviations: AHI  apnea-hypopnea index; BMI  body mass index; BPC  bodily pain component; ESS  Epworth sleepiness scale; GHC  general health component; MHC  mental health component; OSA  obstructive sleep apnea; OSAS  obstructive sleep apnea syndrome; PFC  physical function component; PRC  physical role component; REC  role emotional component; SDB  sleep-disordered breathing; SFC  social function component; SF-36  Medical Outcomes Study 36-item short form; VTC  vitality component E pidemiologic studies 1–3 performed during the last 15 years have demonstrated that obstructive sleep apnea (OSA) is a common disorder. Indeed, 16 to 24% of adult men are estimated to have at least mild OSA (defined as an apnea-hypopnea index [AHI] of  5 events per hour), while 9 to 14% of adult men are reported to have at least moderate OSA (defined as an AHI of  15 events per hour). Additionally, the 5-year rates of mild and moderate OSA were estimated by Tishler et al 4 to be 16% and 10%, respectively. As a result of sleep fragmentation and respiratory effort-related arousals, OSA is often accompanied with excessive daytime sleepiness (ie, OSA syndrome [OSAS]). It is estimated that 5% of Original Research SLEEP MEDICINE www.chestjournal.org CHEST / 134 / 1 / JULY, 2008 79