A new study by researchers at the University of Washington suggests that even a brief period of “low-power” cellphone use during sleep could pose a health risk.
The researchers found that the sleep-wake cycle, which is known to affect our circadian rhythms and our bodies’ biological clocks, could be affected by how much time people spend in a bed or other open space.
The study, published in the journal Circadian Rhythms, was led by Dr. James J. Wray, a professor of medicine at the UW and the lead author of the study.
The new findings are “the first to suggest that the circadian rhythm is influenced by the amount of time spent in bed,” Wray said in a press release.
He added that the researchers have no way to know how much of a connection that sleep-related disruption has to the circadian clock.
The research is preliminary, but preliminary research has suggested that the impact of sleep-induced disruption is greater in older adults and people with compromised health.
In addition, the researchers found a relationship between the amount and timing of the light exposure during the sleep cycle and the level of sleepiness in older people.
The team examined how people slept during a 24-hour period in three states.
They found that in the first 24 hours of sleep, the average amount of light exposure was 8 hours, 21 minutes, while the average number of hours of darkness during the night was 5 hours, 22 minutes.
In the second 24 hours, the sleepers were exposed to 10 hours of light each night, while in the third 24 hours the sleep was reduced to 8 hours of dark each night.
Researchers also found that people who slept longer were more likely to have higher levels of the sleep hormone melatonin than those who slept shorter.
“We found that older adults who sleep less than 6 hours are less likely to report daytime sleepiness,” said Wray.
“This suggests that, at least for some people, the length of sleep can influence their sleepiness during the daytime.”