Diminished capability to recognize the optimal temperature for sleep initiation may contribute to poor sleep in elderly people.
OBJECTIVE
Sleep propensity and skin temperature are functionally related. In young adults, changes of skin temperature within the comfortable thermoneutral zone affect sleep-onset latency and vigilance performance. Aging is associated with both decreased thermosensitivity and poorer sleep. Our goal was to test whether subtle manipulations of core body and skin temperature affect sleep onset in elderly people without sleep complaints and in elderly insomniacs and whether the subjective perception of these mild body temperature manipulations is preserved with aging and insomnia.


METHODS
In a 2-day semiconstant-routine protocol, 288 sleep-onset latencies were polysomnographically determined while manipulating core body and skin temperatures differentially in warm and cold directions within a comfortable thermoneutral range.


METHODS
Sleep laboratory of the Netherlands Institute for Neuroscience.


METHODS
Eight elderly subjects without sleep complaints (65.8 +/- 2.8 years, mean +/- SEM) and 8 elderly insomniacs (59.1 +/- 1.9 years).


RESULTS
Warming the proximal skin by 0.4 degrees C facilitates sleep onset equally effective in healthy elderly (by 18% ie, by 1.84 minutes [95% confidence interval [CI], 0.76-2.92]) and elderly insomniacs (28%, 2.85 minutes [CI: 2.55-3.18]). These effects were comparable to the results in healthy young subjects, in spite of a marked decrease in the subjective perception of temperature changes in elderly subjects, especially in insomniacs.


CONCLUSIONS
The findings show that mild changes in skin temperature have an effect on sleep propensity in elderly and indicate that elderly insomniacs may have a diminished capability to recognize that a slight increase in bed temperature facilitates the initiation or reinitiation of sleep.
Raymann
Roy J E M
RJ
Netherlands Institute for Neuroscience, Amsterdam, The Netherlands.
Van Someren
Eus J W
EJ
D000368:Aged; D001143:Arousal; D001288:Attention; D001364:Awareness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012881:Skin Temperature; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000209:etiology*; D012894:Sleep Stages
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