Sleep Research: New Findings About Diabetes, Loneliness and Apnea

Diabetes Tied to Poor Sleep

Poor sleep has been linked to eating more and moving less. And now a Japanese study indicates that losing just six hours of sleep may affect the liver’s ability to produce glucose and process insulin.

Researchers from Toho University Graduate School of Medicine in Tokyo fed two groups of mice unlimited high-fat food and sugar water, according to a Sept. 5 news release from Science Daily. The mice in the first group were kept awake for six hours, while the control group slept as they pleased.

Researchers explained the reason for the experiment: “It was not clear whether glucose intolerance was due to the changes in food intake or energy expenditure or to the sleep deprivation itself.”

After one six-hour period of wakefulness, the sleep-deprived mice had higher blood glucose levels, as well as higher triglyceride (fat) levels and higher glucose production in the liver. Higher triglycerides are associated with insulin resistance.


Sleeplessness Triggers Loneliness

Just one night of poor sleep can make you feel lonely and less inclined to interact with others. And it makes others less likely to interact with you, as well.

Researchers at the University of California, Berkeley, discovered this two-way relationship between sleep loss and social isolation after conducting a series of experiments on 18 young adults after a full night of rest and one sleepless night, according to an Aug. 15 news release on Science Daily.

The experiments included fMRI brain imaging, standardized loneliness measures, videotaped simulations and surveys. In the videotaped simulations, study participants watched people with neutral expressions walk toward them. They were asked to stop the video when they got too close. When sleep deprived, participants kept the people 18% to 60% farther back than when they had an adequate amount of sleep. Their brains showed high activity in the “near space network” that perceives threats and a shutdown of the “theory of mind” network that encourages social interaction, the release said.

Not only did the sleep-deprived subjects keep others at a distance, but those who watched videotapes of them found them to be lonely and not someone with whom they would want to spend time. Additionally, the loneliness appeared to be viral — others who watched the videos of the sleep-deprived subjects felt alienated after just watching a 60-second clip.

“It is perhaps no coincidence that the past few decades have seen a marked increase in loneliness and an equally dramatic decrease in sleep duration,” said study lead author Eti Ben Simon, a postdoctoral fellow in Walker’s Center for Human Sleep Science at UC Berkeley. “Without sufficient sleep we become a social turn-off, and loneliness soon kicks in.”

But Matthew Walker, study senior author and UC Berkeley professor of psychology and neuroscience, added a positive note. “Just one good night of sleep makes you feel more outgoing and socially confident, and furthermore, will attract others to you,” he said.


Apnea More Likely With PTSD, Mood Disorders

Male military veterans who have a combination of post-traumatic stress disorder and mood disorders also are more likely to have sleep apnea, a study by The University of Texas at Dallas found.

Researchers analyzed the health records of 413 veterans who visited a psychiatry outpatient clinic over a fourth-month period, according to a news release from UT Dallas. The veterans were asked about their sleep and those who thought they might have sleep apnea did a sleep study to confirm it.

The scientists found that 52% of men with PTSD and bipolar disorder had sleep apnea. The percentage rose to 58% when the vets had PTSD and major depressive disorder. Those without PTSD had lower rates of sleep apnea — 17% bipolar and 38% depression.

“It is already known that there is a higher incidence of sleep apnea in patients with major depression or PTSD, but there seems to be an even higher bump in apnea when they go together,” said William Katz, professor of communication disorders in the School of Behavioral and Brain Sciences at the university.

But while sleep apnea is more common in those who have a combination of PTSD and mood disorders, the connection isn’t completely clear.

“Correlation is not causation, so it’s a bit difficult to know which way it goes,” Katz said. “It could be that individuals with PTSD have horrible nightmares, which break up their sleep. It could also go the other way, where having sleep apnea kind of wakes you up and then leads to more PTSD symptoms.”