Age differences in the spontaneous termination of sleep

Abstract

The stage from which the spontaneous ending of sleep occurred was investigated in 138 sleep episodes obtained from 14 younger (19–28 years) and 11 older (60–82 years) individuals. The possible influences of circadian phase and quality of the preceding sleep period, as well as the impact of aging on characteristics of sleep termination were examined. Under experimental conditions in which subjects were isolated from time cues, and behavioral options to sleep were limited, no age‐associated differences in the duration of sleep periods, or in the number or duration of REM episodes were observed. Despite similar percentages of NREM (stages 2–4) and REM sleep across age groups, younger subjects awakened preferentially from REM while older subjects did not. Of the sleep episodes obtained from older subjects, those with sleep efficiencies higher than the median were more likely to terminate from REM than those with lower sleep efficiencies. For all subjects, the REM episodes from which sleep termination occurred were truncated relative to those that did not end the sleep period. In addition, nonterminating REM episodes that were interrupted by a stage shift were most often interrupted by brief arousals to stage 0. Such arousals within nonterminating REM episodes occurred, on average, after a similar duration as the terminating point of sleep‐ending REM episodes. The results from this study demonstrate that there are age‐related differences in the sleep stage from which spontaneous awakenings occur, and that these differences may be due in part to the quality of the sleep period preceding termination. Findings regarding the characteristics of both terminating and nonterminating REM episodes are consistent with the notion that the neural and biochemical context of REM sleep may facilitate a smooth transition to wakefulness. It is speculated that age‐associated changes in sleep continuity may render unnecessary the putative role of REM sleep in providing a ‘gate’ to wakefulness.

The Effects of Pre-Sleep Learning on Sleep Continuity, Stability, and Organization in Elderly Individuals

“…While the latter are characterized by a tendency to spontaneously wake up from REM sleep, therefore with a higher degree of sleep fragmentation in the last part of the sleep episode (Langford et al, 1972; Murphy et al, 2000), and longer wake in late than in early sleep cycles (Merica and Gaillard, 1986), the former seem vulnerable to fragmentation all over the sleep episode. In the present study, this is actually true not only for behavioral awakenings, but also for arousals and state transitions.…”

Changes in REM-Sleep Percentage Over the Adult Lifespan

“…Several researchers have reported that REM% declines as adults age, [5][6][7][8][9][10][11][12][13][14][15][16][17][18] whereas several other researchers have reported no age-related decline in REM%. [19][20][21][22][23][24][25] Collectively, these findings suggest that any decline in REM% with age is either very small, and therefore difficult to detect, or nonexistent. It is also possible that the decline in REM% is nonlinear in nature, in which case the linear component of the decline could be masked in some studies and not others, depending on the age range examined.…”

Rapid eye movement activity before spontaneous awakening in elderly subjects

“…In fact, whereas spontaneous awakenings come mainly from rapid eye movement (REM) sleep in young subjects (Campbell 1975), in the elderly they emerge both from REM sleep and from stage 2 (Dijk et al. 2001; Murphy et al. 2000; Salzarulo et al.…”

“…Not only do they wake up more than subjects at other ages (Bliwise 1993;Webb 1982) but they also show longer durations of the awakenings (Akerstedt et al 2002;Garma et al 1981) and different frequencies of awakening from each sleep state. In fact, whereas spontaneous awakenings come mainly from rapid eye movement (REM) sleep in young subjects (Campbell 1975), in the elderly they emerge both from REM sleep and from stage 2 (Dijk et al 2001;Murphy et al 2000;Salzarulo et al 1999).…”