Sleep disordered breathing in the elderly

Sleep disordered breathing (SDB), i.e., obstructive, central or mixed sleep apneas, has been recognized as a common occurrence in the elderly. Aging i s per se associated with a decrease in the quality of sleep; SDB may furthe r disrupt the sleep architecture in older subjects. The prevalence of obstr uctive sleep apnea (OSA) increases with aging; available studies report pre valence rates of 11-62%. Furthermore, OSA has been associated with increase d mortality in older adults. Central apneas and periodic breathing occur wi th increased frequency either in subjects with neurological disorders such as infarction, tumor, sequelae of infection, diffuse encephalopathies, or i n chronic heart failure. Patients with cerebrovascular disease (stroke, or transient ischemic attacks) have a markedly high prevalence of SDB, mainly OSA. In these patients, SDB is associated with a poorer functional prognosi s at 3 and 12 months after the acute event, and a higher mortality. The cli nical impact of SDB on cognitive function appears to be modest in patients without dementia, although there is a moderate increase in daytime sleepine ss. In Alzheimer's disease (AD) however, SDB occurs more frequently than in non-demented older subjects, and its severity is correlated with the degre e of cognitive impairment. The hypothesis of a causal relationship between AD and SDB remains a subject of controversy. The possibility of SDB should be considered in the elderly in the differential diagnosis of "reversible d ementias", increased daytime sleepiness, or unexplained right-sided heart f ailure.