Sleep-disordered Breathing (sdb) Is a Condition Characterized by Repeated Breathing Pauses and Reduced Airflow during Sleep, Leading To

1309 SLEEP-DISORDERED BREATHING (SDB) IS A CONDITION CHARACTERIZED BY REPEATED BREATHING PAUSES AND REDUCED AIRFLOW DURING SLEEP, LEADING TO nocturnal arousals, unrefreshing sleep, and daytime sleepiness. SDB has been shown to be a contributing factor in diminished neurocognitive functioning.1-4 Specifically, within the spectrum of neurocognitive deficits, vigilance impairment or inability to sustain attention is a frequent complaint of patients with SDB. Vigilance lapses have been shown to be associated with sleepiness—regardless of the cause—as well as with fatigue and alcohol impairment,5-7 and the lapses have been found to be tightly coupled to slow eyelid closures,8 which increase in frequency with drowsy driving 9 and contribute to motor vehicle crashes and occupation-related accidents.10 Significant associations between SDB and impaired vigilance have been shown in patient-based studies.3,11-13 Because these studies were based on patients who may have been more likely to be have been referred to a sleep clinic if they experienced impaired vigilance, the association between SDB and impaired vigilance may be overstated and may not be applicable to SDB in the community-based population. In contrast with the results from patient-based studies, no significant relationships between SDB and vigilance impairment have been reported in samples of older community-dwelling adults selected independently of sleep complaints.14,15 Although the data suggest that SDB in older people may not be associated with impairment, it is possible that methodologic differences, restricted age range, selection bias, or small sample size may explain the discrepancies in the findings between these and the findings from the patient-based studies. SDB is common and the range of SDB severity is wide, but no studies on the association between SDB and vigilance in the community population based on a large sample have been reported that span the full range of SDB severity and age range in adults. In a large community-based sample of middle-aged and older adults, we assessed the independent association between SDB and vigilance impairment as assessed by the psychomotor vigilance task (PVT), an instrument that is widely used in assessing the maintenance of alertness related to sleep deprivation and sleep disorders.7 In addition, data on self-reported and polysomnographically determined sleepiness provided the opportunity to assess whether sleepiness mediates the associations of SDB with vigilance impairments and the impact of sleepiness on vigilance performance in a nonclinical population.