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Science of snooze

By Alex Piazza
apiazza@umich.edu

Call it a miracle drug.

It has the power to improve your mood. It can increase your concentration at work. And a healthy dose can prevent future trips to the emergency room.

It’s called sleep, and although it comes free of charge, at least 40 million Americans struggle every year to get enough. And the consequences can be dire.

“Sleep is very much a public health issue because it affects everything we do,” said Ronald Chervin, a neurology professor at the University of Michigan. “The problem is many people treat sleep as the last priority. They treat it like a sponge that can be infinitely compressed whenever they need time for something else. That’s a total misconception.”

Cue Chervin who, along with several of his U-M colleagues, studies sleep and the ill effects caused by a lack of shuteye.

“We spend a third of our lives asleep, so to go through an entire lifecycle and never have an issue with sleep is very unusual,” he said.

Chervin leads a group of specialists at the U-M Sleep Disorders Center, where researchers study sleep and its impact on human health, as well as how sleep disorders target vulnerable segments of the population, like people who are young, old, pregnant or depressed.

“We have one of the largest and best-developed academic sleep programs in the United States,” Chervin said. “The University of Michigan has 40-plus faculty who have major research interests in sleep, and those interests span four schools and 15 departments. We see over 8,000 patients a year. We have 28 beds where we’re conducting sleep studies every night, seven days a week. And as our population continues to age, we’re going to be faced with a huge influx of people with sleep disorders. We have a real opportunity here—in terms of faculty number and diversity, the patient population and exceptional resources—to offer international leadership in sleep research.”

The university is well on its way, as a number of researchers across campus have embarked on groundbreaking studies that highlight the impact of sleep on serious medical conditions.

Sounds of sleep

It’s that loud, unpleasant noise that emanates from millions of bedrooms every night.

It’s the reason why many men and women gently nudge their partners in hopes they can fall back asleep.

It’s snoring and about 24 percent of adult men do it every night, according to the American Academy of Sleep Medicine. Nearly 10 percent of adult women do it, too.

Snoring is a sign that your airway is partially blocked during sleep, usually by soft tissue in your throat. The airflow causes the soft tissue to vibrate, generating the noise. 

Frequent or loud snoring can be a hallmark symptom of obstructive sleep apnea, a serious sleep disorder in which breathing repeatedly stops and starts. Sleep apnea, which affects more than 18 million Americans, could have detrimental effects on pregnant women and their unborn children.

Sleep apnea can cause high blood pressure in mothers and possible growth restriction among newborns, said Louise O’Brien, associate professor in the Sleep Disorders Center.

“What we’re learning now is that symptoms of sleep apnea increase significantly during pregnancy, with up to 35 percent of women snoring frequently by late pregnancy,” she said. “And it affects not only the mother, but the baby, too.”

O’Brien and her colleagues recruited pregnant women to participate in sleep studies, and they found that half of the participants with high blood pressure who snore regularly unknowingly had obstructive sleep apnea. They also found that pregnant women who snore are at a higher risk for C-sections.

“Habitual snoring—especially in women with high blood pressure— may be one of the most telling signs to identify the risk of sleep apnea early in order to improve health outcomes,” O’Brien said.

“Habitual snoring—especially in women with high blood pressure— may be one of the most telling signs to identify the risk of sleep apnea early in order to improve health outcomes,” O’Brien said.

Many people turn to continuous positive airway pressure (CPAP) therapy to treat their sleep apnea. They hook up to a small machine that supplies a constant and steady stream of air pressure to keep their airway open overnight.

But many health care providers wait until after the baby is born to administer CPAP therapy, which O’Brien said may be a mistake because early treatment of the mother could improve the baby’s health.

“We had an incident once where a woman couldn’t feel her baby moving, so right away we hooked her up to a CPAP machine,” O’Brien said. “Not only did her oxygen levels increase—she started to feel her baby move again. It turned out she had severe obstructive sleep apnea that no one knew about.”

Foggy headed

Coffee just won’t cut it this morning.

And it doesn’t take long for reminders of that sleepless night to creep into your daily routine.

You’re irritated by traffic during your morning commute. You doze off during an important work meeting. And you can’t think clearly at your desk.

Fatigue and mental fogginess are ugly consequences of sleep deprivation, often caused by a variety of one or more sleep disorders. But for the 2.3 million people with multiple sclerosis (MS), the impact may be much worse.

About 80 percent of people with MS—an unpredictable, often disabling disease of the central nervous system—report symptoms of chronic fatigue, according to the National MS Society. Another 70 percent of MS patients report cognitive dysfunction, which factors into why so many people with the disease prematurely leave the workforce.

But what if their fatigue or cognitive problems were caused or worsened by a common sleep disorder? That is a primary research focus of Tiffany Braley, a U-M assistant professor of neurology.

Braley and her colleagues screened nearly 200 patients from the U-M Multiple Sclerosis Center for a number of sleep disorders, including obstructive sleep apnea. They found that 56 percent of participants were at increased risk of sleep apnea, a significant predictor of fatigue, yet most had never received a formal diagnosis.

“Sleep disorders, such as obstructive sleep apnea, independently contribute to fatigue in people with MS,” she said. “If we can identify and treat their sleep disorder, we might be able to offer substantial improvement in their quality of life and overall health.”

Braley soon plans to launch a new clinical trial, funded by the National MS Society, that will measure the effects of a popular sleep apnea treatment on cognitive function and fatigue in MS patients.

“If patients are fatigued or suffering from a cognitive disorder, you can try to place a Band-Aid on the problem by giving them a pill to keep them alert, or you can actually get to the root cause of the problem and improve their overall health,” she said.

Brighter days ahead

Millions of people stare at the ceiling each night as they struggle to sleep.

Their favorite activities no longer bring them joy.

Minor setbacks spark outbursts of anger or extended periods of sadness.

They’re common symptoms of depression, a condition that affects about 16 percent of Americans.

Standard treatments take a long time to work and are only partially successful, so scientists continue to search for new ways to ease symptoms of depression.

Since sleep problems are inherently common in depression, researchers worldwide have tested whether sleep-focused strategies can have a positive impact on depression.

One paradoxical finding has been that drastic sleep deprivation can immediately improve depression symptoms. But symptoms usually return when sleep is allowed the next day and keeping people awake all night can have dangerous consequences the next day.

So J. Todd Arnedt took a different approach and evaluated whether a more modest form of sleep deprivation would spur similar benefits to drastic sleep deprivation without the side effects.

The U-M associate psychiatry professor recruited about 70 adults diagnosed with depression and provided each with an antidepressant medication for eight weeks. Half of the participants were asked to spend eight hours in bed each night for the first two weeks, while the other half had to spend six hours in bed nightly—a modest cutback compared to previous studies that asked participants to stay up all night, but still less sleep that most people need on a nightly basis.

“It’s well known that it takes an extended period of time before antidepressant medication takes effect—anywhere from six to eight weeks,” Arnedt said. “Anything we can do to reduce that period would be a huge benefit to millions of people who suffer from this debilitating mental illness.”

“A number of previous studies have looked at extreme forms of sleep deprivation for depression, but I wanted to see whether sleep duration during the early stages of treatment had any sort of impact on how people respond to antidepressant medication,” said Arnedt, director of the U-M Sleep and Circadian Research Laboratory, a research facility that studies the role of sleep and circadian rhythms in psychiatric disorders. “What we found is that the amount of sleep obtained during depression treatment matters and critically affects people’s response to their depression medication.”

Contrary to what total sleep deprivation studies in depression have found, his study revealed that participants who were in bed for eight hours each night—an adequate nightly sleep duration—during the first two weeks of antidepressant treatment had greater mood improvements than those who stayed in bed for only six hours nightly. And by the end of eight weeks of treatment, 75 percent of the participants who were in bed for eight hours also experienced remission from their depression symptoms. Depression remission also occurred on average one week earlier for depressed individuals in the 8-hour sleep group

“It’s well known that it takes an extended period of time before antidepressant medication takes effect—anywhere from six to eight weeks,” Arnedt said. “Anything we can do to reduce that period would be a huge benefit to millions of people who suffer from this debilitating mental illness.”

 

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