NEW RESEARCH FOR YOU - Manipulating Body Temperature to Control Narcolepsy Published on December 11, 2014

By Karen Appold

Disturbed nocturnal sleep is a major complaint of patients with narcolepsy. In their research, Eus JW Van Someren, PhD, head of department, Professor of Neurophysiology, Department Sleep and Cognition, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands, and colleagues found that skin temperature affects sleep onset and sleep depth in individuals without sleep complaints and in people suffering from insomnia.

Given that, in a study published in Sleep1 the authors aimed to evaluate whether skin temperature manipulation was also effective in narcolepsy. During two nights, sleep was recorded polysomnographically while proximal and distal skin temperature were manipulated using a comfortable thermosuit that induced skin temperature to cycle slowly with an amplitude of only 0.4˚C within the comfortable range normally observed during sleep.

The study found that proximal skin warming significantly suppressed wakefulness and enhanced slow wave sleep (SWS). In contrast, distal skin warming enhanced wakefulness and stage 1 sleep at the cost of SWS and rapid eye movement (REM) sleep. The optimal combination of proximal skin warming and distal skin cooling led to a 160% increase in SWS, a 50% increase in REM sleep, and a 68% decrease in wakefulness, compared with the least beneficial combination of proximal skin cooling and distal skin warming, Van Someren reports.

Upon reflecting on the results, Van Someren says that the researchers did not expect that distal skin warming would adversely affect sleep; this was not previously reported in people without narcolepsy. “Over all of our studies, proximal skin temperature most robustly affected sleep,” he says.

So what do the findings mean for a clinical setting? “Although we found that controlled mild proximal warming using a thermosuit improved sleep, bed warming by means of a heating blanket is not advised,” Van Someren says. “The body temperature will rise to a level that doesn’t favor sleep.”

Feedback-loop-controlled systems need to be developed to continuously monitor skin temperature and manipulate the bed temperature from moment to moment in the best direction up or down. Such a system does not yet exist. A trick that uses the body’s own thermoregulatory system may help: raising body temperature through exercise or a warm bath, but only between two to three hours prior to bedtime.