Sleep in healthy elderly subjects: a 24-hour ambulatory polysomnographic study

It is still debated whether the deterioration of the sleep pattern, frequently reported by elderly subjects, is due only to aging per se. Other factors associated with aging or modifications of biological rhythms could also be involved. Elderly subjects frequently complain of daytime sleepiness, but it is not clear whether this actually represents a return to a polyphasic structure of sleep, or only a consequence of a disturbed night sleep. Ten healthy, independent and active elderly subjects (age > 72 years) were elevated by means of 24-hour ambulatory polysomnography. Findings of nocturnal sleep were compared with sleep of the same group in the 24-hour period and with sleep of young healthy controls. We observed a fragmentation of nocturnal sleep, but a fairly good representation of stages and a preservation of cyclicity. Except for three cases, with early or late times of sleep onset and wake-up, sleep disruption did not seem to be related to modification of circadian rhythms. Only three subjects presented undesired daytime naps, whereas the others either did not show daytime sleep at all, or were used to having their siesta after lunch since their young adulthood. In normal aging, daytime sleep does not constitute a social problem. Ambulatory polysomnography is a valid alternative to laboratory recordings in the identification of daytime sleep.