Obstructive sleep apnea syndrome, sleepiness, and quality of life

Objective: To evaluate the addition of short arousals of > 3 s on indexes of sleep-disordered breathing (SDB) and subjective sleepiness in patients with obstructive sleep apnea (OSA), and to evaluate the quality of life and reported difficulty driving with arousal index and indexes of SDB. Method: Data was collected from a general clinical evaluation, and evaluations using the Epworth sleepiness scale (ESS), the sleep disorders questionnaire, the Beck depression inventory (BDI), the Medical Outcomes Study 36-item short form health survey (SF-36), a questionnaire on driving difficulties and accidents, and polysomnography. Results: A total of 135 male subjects (mean [+/- SD] age, 52 +/- 12.1 years; mean body mass index [BMI], 27.8 +/- 5.6 kg/m(2); mean apnea-hypopnea index [AHI], 48.7 +/- 26.8 events per hour) were studied. Of these subjects, 70.4% acknowledged having driven while sleepy. ESS scores correlated significantly with the arousal index and AHI, and negatively with the lowest arterial oxygen saturation. The "physical functioning," "general health," and "role physical" subscales of the SF-36 correlated with the arousal index. No significant correlation was seen in multiple regression analyses after adjusting for age and BMI, using "reports of sleepiness while driving" as the dependent variable. Conclusion: Several subjective complaints and subscales of the SF-36 correlated significantly with a frequency of SDB-related arousal of > 3 s. Patients perceived that an organic health problem had been impairing their quality of life more than an emotional problem, despite elevated scores on the BDI. However, if sleepiness while driving was common in OSA patients, it was not significant. Many clinical and polysomnographic variables may be considered as possible independent variables in the regression analysis. Other unrelated factors have a greater impact. To relate sleepiness while driving only to the usually studied variables in OSA patients is an oversimplification.