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December 9, 2010

How to improve your sleep

As many as half of the adults in the United States suffer an occasional bout of insomnia, and for 5-10 percent of Americans it is a serious chronic problem.

Buysse“Insomnia is defined as difficulty with falling or staying asleep,” said Daniel Buysse, professor of psychiatry and clinical and translational science at the School of Medicine. It’s the most common sleep disorder and “it’s more common in women than men and [incidents] tend to increase with age.”

Buysse spoke last month on “Getting Better Sleep: What You Need to Know,” part of the community-based health and wellness lecture series hosted by Carnegie Library.

“Insomnia, however, does not equal sleep deprivation,” said Buysse, who also is director of the Clinical Neuroscience Research Center and medical director of the sleep evaluation center at Western Psychiatric Institute and Clinic. The difference, he said, is that with insomnia there is adequate opportunity to sleep, but reduced ability to sleep or poor quality sleep; with sleep deprivation, whether done by choice or due to shift work or other time commitments, there is reduced opportunity to sleep but adequate sleeping ability.

The ramifications of both insomnia and sleep deprivation include impaired concentration, performance and learning functions; daytime fatigue; irritability; mood changes; changes in blood pressure and glucose control and, potentially, long-term health effects, such as obesity, diabetes, depression and shortened life expectancy. All of these outcomes are documented by scientific studies, Buysse said.

In addition, there are potential physical dangers, he said. “Some data suggest that as many as one in seven single-vehicle car crashes involve a driver who fell asleep. Like many other things, car crashes are not randomly distributed between day and night. The peak number of single-vehicle crashes are between 4 a.m. and 8 a.m. — not the time most cars are on the road, but it is the time when people are sleepy.”

Other notable accidents, such as the Chernobyl nuclear accident and the Exxon Valdez accident, have been linked to overly tired personnel, he added.

But the good news is there are medications and psychological-behavioral treatment strategies to combat insomnia, he said.

According to Buysse, those medications include:

So-called sleeping pills, such as Ambien, Lunesta and temazepam, all of which are FDA-approved and have been deemed safe and effective, although there is some question about whether they are safe for long-term use;

Sedating antidepressants, such as trazodone and doxepin, which are effective for many people with insomnia, but may have serious side effects for some;

Melatonin and melatonin-like drugs, such as Rozerem, and

Antihistamines, such as Benadryl, Uni-Som and Tylenol PM, which are over-the-counter and inexpensive, although they have not been demonstrated in clinical trials to be effective against insomnia, and

Natural agents, such as valerian, which are effective for some.

The psychological-behavioral treatments include “sleep hygiene,” that is, practicing habits that help sleep, such as relaxation exercises that calm the mind or reading to increase drowsiness.

To treat insomnia, Buysse said, sufferers actually should reduce their time in bed; try to get up at the same time every day of the week no matter how much sleep they got the night before; only go to bed when they are sleepy, and not stay in bed unless they fall asleep quickly.

“Make the bedroom only for sleep. If you’re in bed and can’t fall asleep, get up and do something until you get sleepy,” Buysse recommended.

He said that scientists believe insomnia results when the brain is in a state of hyper-arousal, which could be due to taking medications, to excess worry or anxiety or to medical conditions, such as depression.

“The brain controls sleep based on two major factors: how long you’ve been awake and your biological clock,” Buysse said. “The brain responds to how long you’ve been awake. It’s like a rubber band: The longer you’re awake, the more the rubber band stretches, tighter and tighter, until eventually there comes a point that sleep becomes involuntary behavior,” he said.

The unofficial world record for staying awake is 11 days, “done by a high school student with a lot of help,” Buysse said. “At the end you couldn’t really tell whether he was asleep on his feet. But that’s really extreme; it’s very difficult for people to extend the time they’re awake.”

Regarding the biological clock, Buysse said, “Our planet has a night environment and a day environment. People and other animals and even plants have to adapt to the fact of an environment characterized by the 24-hour light-dark cycle, or circadian rhythm.”

The term circadian derives from the Latin circa (approximately) and diem (day) — that is, they are rhythms that are about a day in length.

“Why do people have circadian rhythms? That’s not easy to answer. But we do know that for better or worse circadian rhythms are a basic fundamental property of living organisms from plants to humans. Rhythms are just a fact of life,” Buysse said.

The first time such rhythms were observed was in plants, he said, during an experiment involving a plant that flowered regularly at dawn and dusk. “The plant was put it in a darkened environment and still flowered, meaning that there had to be some sort of internal rhythm,” Buysse said. “For humans, in some basic way, we think that circadian rhythms help us to match our rest-activity patterns and our functioning in the light-dark cycle. This is kind of reverse reasoning on evolution, but if you think about it, human beings are very visually driven, so it’s a happy circumstance that we’re most active and alert when we can make most use of our vision during daylight hours,” he said.

“If you were a rat and got around primarily by your whiskers, then dark would be your best time,” he added.

“But somehow these adaptations help match the organisms to their light-dark environment, and to do that, we need a way of ‘predicting’ internally when it’s going to be a light or dark cycle.”

Scientists now have demonstrated that human circadian rhythms are based in the genes. “There are about a dozen genes operating in every cell in your body that have rhythmic discharges typically higher during the daylight hours and lower at night, so even down to the cellular level we have these rhythmic functions that key us to the light-dark cycle,” Buysse explained.

About 99 percent of the brain is more active when a person is awake. “But there are very few small places in the brain that are more active when we’re asleep, and their activity is to switch off all the arousal centers,” he said.

Properties of circadian rhythms

“We know that circadian rhythms follow the light-dark cycle, but they are not caused by the light-dark cycle, they are endogenous, that is, internal to the organism,” Buysse said. “You can eliminate light-dark cues — for example, what happens above the Arctic circle — and people will continue to have 24-hour rhythms, because of the endogenous, internal aspect of our physiology.”

At the same time, he said, these rhythms can be synchronized to the environment. “In normal circumstances, you don’t find part of the population sleeping from 9 a.m. to 3 p.m. and part of the population sleeping from 3 p.m. to 10 p.m. Almost everybody, all things being equal, will sleep at night and be awake by day, because people are synchronized by light. Of the various time cues, light is the strongest one. In other words, your body is very sensitive not only to the fact of light, but to when that light occurs.”

Science has shown that circadian rhythms for humans are not precisely 24 hours long. “They’re actually about 6 minutes longer than 24 hours. So every day we have to reset our internal clocks a little bit earlier, constantly pushing forward a little bit. If you think about weekends, people tend to stay up later, then Monday morning comes and — uh, oh — you have to get up earlier, and that’s the time that lack of sleep can affect you,” Buysse said.

That fact helps explain why people typically find it easier adjusting when they fly westward than eastward, “because our clocks can easily deal with the delay, but not as easily with an advancing or shortening schedule since our internal clocks run a little bit longer than 24 hours,” he said.

“Your biological rhythms in the natural world don’t reset immediately, which explains jet lag. The biological clock takes a few days to recover. The most human beings can adapt is about an hour a day. So, if you go to California, it will take a few days to reset; if you go to Europe it will take close to a week,” Buysse said.

“If you stay up all night and into the next day, the biological clock will offset that within limits, which explains the sense of a ‘second wind,’” he said, adding that that sensation is artificial and temporary.

How much sleep is normal?

“There are, of course, profound differences due to age. An infant can sleep many more hours than an adult. As we get older, we get lighter, more fragmented, shorter hours of sleep,” but that can be made up with napping, Buysse said.

(As an aside, Buysse said some people are natural nappers, while others are not; both habits are seen as normal.)

A self-reporting survey of several thousand adults between ages 18 and 60 determined that a majority of people averaged seven hours of sleep a night. By and large, women sleep a little longer on average than men.

“Obviously, people can choose to sleep less time. But beyond certain limits, you can’t really chose to sleep longer. You can give yourself the opportunity, but normally, you can’t sleep 20 hours a day. You just can’t do it,” Buysse said.

Sleeping 7-8 hours a night also translates into the healthiest amount.

“People who average 7-8 hours of sleep in general had lower body mass than those with 6 hours as well as those with 9 hours,” Buysse said.

Instances of metabolic syndrome — a set of cardiovascular risk factors — also are shown to be higher for those at the high and low ends of average sleep amount, he added.

Perchance to dream

“In a normal person, most of our deepest sleep occurs in the first half of the night. After that, dream sleep, or rapid eye movement sleep, alternates with deep sleep about every 90 to 120 minutes,” Buysse said.

“Also, it’s normal for a person to wake up multiple times per night. Even when you think you’ve slept through the whole night, it’s likely that the periods of waking up were so brief you don’t remember them the next morning. Very few people actually do sleep through the night,” so, if a person is aware of waking up multiple times, that is not a problem, as long as the person is able to go back to sleep quickly, he said.

“Also, when you wake up from dream sleep, you’re much more likely to remember your dreams,” Buysse said. While there is no definitive proof, many scientists believe that dreaming is a way for a person to consolidate memories or emotions, he said. “If people are going through a crisis or stressful situations, the mind is trying to process that,” he said. “People with post-traumatic stress disorder have very disturbed sleep that often includes nightmares.”

Other sleep disorders

In addition to insomnia, less-common sleep disorders include sleep-related breathing disorder (sleep apnea); hypersomnia, that is, conditions that cause severe daytime sleepiness, including narcolepsy; circadian rhythm disorders, which are sleep disturbances caused by conflicts with the biological clock (such as shift-work commitments); parasomnias, that is, unusual behaviors during sleep, such as sleep walking or nightmares, and sleep-related movement disorders, such as periodic leg movements, restless leg syndrome or body-rocking.

Various treatments, as well as research studies and clinical trials, are available at Pitt and UPMC for those with these conditions, Buysse said. He recommended first contacting the UPMC Sleep Medicine Center. Those with insomnia, circadian rhythm disorders and parasomnias should call 412/246-6413; those with sleep apnea and other sleep disorders should call 412/648-6161. The web address for the center is sleepmedicinecenter.upmc.com.

—Peter Hart

Filed under: Feature,Volume 43 Issue 8

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