[Modifications in sleep with aging]

Literature reviewed shows that aging sleep is characterized by a decrease in the ability to stay asleep, resulting in a more fragmented sleep and a decrease in daytime alertness. It exists also an advance of phase, a shortening of wake-sleep period and a desincronitation of circadian rhythms.

Changes in circadian rhythms are associated with a decrease of sleep quality. There are a marked reduction of deep slow wave sleep, sleep spindles are less frequent, less ample and shorter. REM sleep appearance is almost uniform during night and REMs density does not increase toward the end of the sleep period. The sleep-wake circadian rhythm is advanced, the temperature rhythm is advanced and the rhythm of cortisol secretion is also advanced. The GH and melatonin peaks of secretion are decreased in elderly.