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Sleep Disturbance Common With Anorexia or Bulimia

Women with eating disorders such as anorexia or bulimia may also experience significant trouble sleeping, suggests a small study in Egypt.

In a comparison of women with and without eating disorders, those with anorexia or bulimia reported insomnia, excessive daytime sleepiness and other sleep disorders like sleepwalking or sleep paralysis much more frequently. Sleep monitoring confirmed their altered sleep patterns, researchers found.

When the study team accounted for depression symptoms - which are also tied to sleep disturbance - most of the links between eating disorders and sleep troubles remained, according to the report in the journal Sleep Medicine, May 7.

"This provides preliminary steps toward understanding sleep problems in eating disorder patients," said one of the study's authors, Dr. Sherien Ahmed Khalil of Ain Shams University in Cairo, in an email.

Eating disorders have been associated with sleep complaints for years, the study team notes. To see how the two problems may be related, the researchers analyzed data on 23 women between 18 and 45 years old who sought help for anorexia nervosa or bulimia at Ain Shams University's Institute of Psychiatry between 2012 and 2014. The researchers also recruited 20 similar women without eating disorders to act as a comparison group.

None of the participants were currently taking medications and none had other physical or neurological illnesses that would affect sleep. Among the women with eating disorders, 35 percent also had mild depression symptoms and another 30 percent had moderate depression.

All of the women completed a sleep disorder questionnaire to describe any sleep complaints, and each underwent an all-night polysomnography test in the institute's sleep lab so the researchers could profile their brain activity during different stages of sleep and waking.

Based on the questionnaires, the women with anorexia or bulimia were more likely to have insomnia of all types, with 6 in 10 reporting difficulty falling asleep and nearly half reporting interrupted sleep. They also were more likely to complain of sleep disturbances including nightmares, sleep-related panic and bruxism, or involuntary teeth grinding during sleep.

"What was really surprising is that nearly all sleep problems were found in anorexia and bulimia patients, and sleep complaints were left uninvestigated and untreated," Khalil said.

The sleep monitoring showed that the women with eating disorders tended to take longer to fall asleep, were less likely to sleep efficiently and were more likely to wake up easily during sleep, compared with the control group. There were no significant differences between anorexia and bulimia patients.

Although difficulty falling asleep and some of the sleep monitoring measurements were associated with the severity of an individual's depression symptoms, most of the sleep disturbances were not, the researchers found.

Now Khalil and colleagues would like to study this question on a larger scale and work on developing ways to improve sleep for anorexia and bulimia patients.

"Everyone having eating or sleep problems should seek help as soon as possible because they interact deeply and can lead to disturbed mood, lower quality of life and affect general functioning," Khalil said in an email.

Future research should also distinguish between the subtypes of anorexia - those who restrict food intake but don't purge, as compared to those who binge-eat and purge food, said Dr. Tokusei Tanahashi of Saiseikai Fukuoka General Hospital in Fukuoka, Japan, who wasn't involved in the study.

"Patients with purging behaviors tend to have worse sleep quality," he told Reuters Health by email. "They're also more likely to have disrupted sleep patterns, including circadian rhythm disruption and abnormal sleep duration."

Researchers are beginning to study bright light therapy as a way to treat circadian sleep-wake disorders, which could help those with binging and purging behaviors to sleep better, Tanahashi added. They also want to better understand orexin, a neuropeptide in the brain's hypothalamus that has been associated with eating behaviors, as well as sleep.

Merck's Belsomra (suvorexant) is the first in a new class of orexin-receptor blocking drugs to have been approved in the U.S. as a sleep aid.

"The relationship between eating and sleep is important, however, it's an undeveloped field," Tanahashi said. "Orexin receptor antagonists may have the potential to treat eating disorders."