Medicine For People!

March 2011

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The Secret of Sleep

We all love waking up after a great night's sleep, feeling rested, calm and alert. Shakespeare said it best.

Sleep that knits up the ravelled sleeve of care
The death of each day's life, sore labour's bath
Balm of hurt minds, great nature's second course,
Chief nourisher in life's feast.

It's true that a good night's sleep results in higher mental acuity while sleep deprivation not only makes you grumpy but lowers your immune system. Still, a surprising number of people worry needlessly about sleep. Jakdej Nikomborirak MD, Jefferson Healthcare's sleep medicine specialist, gets many complaints from new retirees, wishing they could sleep better. He asks when they go to bed; they say 10 p.m. When do they get up? 7 a.m. He responds that, no matter how hard they try, most people just cannot stay asleep nine hours a day. His advice is to get up when they are awake and get on with their day.

Sleep Myths

The modern myth that we all need eight hours sleep each night is just wrong. In fact, when researchers surveyed over one million adults, those who reported sleeping around seven hours a night lived longest, and those who slept more than eight or less than six hours fared less well. Those individuals who complained of "insomnia" but reported a total of over six hours sleep had no loss of longevity. They were concerned that they took twenty minutes to fall asleep, or they woke up in the night, or they awakened at 6:00 when they wanted to sleep until 7:00. Alertness is the major measure of adequate sleep. Most people average less than eight hours sleep yet spend the next day alert and awake.

I suspect we worry about sleep because we remember our youth, when our head would hit the pillow and the lights would go out and not come on again 'til morning. Even then, though, we had sleep cycles. These cycles average 90 minutes, start with deep levels of sleep followed by dreaming and then a short time of very light sleep or awakening, and then start again. As we age, we may become more aware of the brief wakefulness. But at all ages this cycle repeats throughout the night.

Sleep Perception Disorder

Today people often feel that they don't get enough sleep when they actually do. This could be thought of as a sleep perception disorder.

Sleep doctors in Hershey, Pennsylvania studied this phenomenon. They recruited, at random, 1400 people out of the telephone book and selected 560 normal sleepers and 115 who felt they had insomnia but tested negative for sleep apnea. They tested everyone's mental capacities and then ran them through a comprehensive sleep assessment in the lab.

The first big surprise occurred when over half of the insomniacs, wired up, tubed up, and put to bed in a sleep lab, put in over 6 hours of shut-eye. The second occurred when 40 percent of the happy sleepers clocked less than six hours.

Message clear? Your perception of how long you sleep could well be wrong. If you are awake and alert during the day, you're very likely sleeping normally and well. If you doubt that, and you don't want to spend $1500 to $2000 for the sleep experts to see how long you really sleep, try out a less expensive home test called actigraphy, which simply measures time asleep.

Fatigue differs from Sleep

Be careful not to confuse fatigue with sleepiness. They are not the same thing, though often confused. Medically speaking, fatigue is a lack of energy for daily activity, which may result from a host of different physical or mental conditions. You can be fatigued but not sleepy. The Epworth Sleepiness Scale can help you figure which problem you have.

Seducing the Sandman

So what if you still are not satisfied with the quality of your sleep? Here are some suggestions.

  • Several studies have shown that people who exercise fall asleep faster. If you can arrange to exercise five or six hours before bedtime, that may provide extra help. But as long as you don't exercise just before bed, the sandman will be happy.
  • No caffeine or other stimulants after lunch. Take your vitamins in the morning, not the evening.
  • Avoid stimulation before bedtime, such as focused work or television news or talk shows. Computer screens are bright, not what we experienced when evolution shaped our sleep-wake rhythms. If you enjoy music near bedtime, choose soothing music.
  • Make sure you are warm and your bed is warm. Massage yourself a little. Fix yourself a cup of hot milk with nutmeg in it.
  • Lights that dim gradually at night or brighten slowly in the morning help many people sleep better. Someone I know uses a book light to read in bed before sleep, the dark room getting her in the mood to doze off. White noise helps some folks fall asleep.

Sleep Restriction Therapy

For people who have trouble getting uninterrupted sleep, sleep restriction therapy often helps. They choose a period they will allot to sleep, perhaps five hours a night. They arise five hours after going to bed for about a week, even though they may be tired and sleepy the first few days. Usually after a few days they start sleeping soundly through those five hours. A week after they've started, they add half an hour to their sleep time, and so on each week until they get to seven or so hours of uninterrupted sleep.

Poor or Insufficient Sleep: The dangers

Many commuters live in a constant state of sleep deprivation, arising at 5:00 am to drive to work and collapsing at midnight after arriving home at 8:00 pm. That lifestyle leads to increased hunger and more risk of high blood pressure and diabetes. Sleep-deprived people run higher levels of grehlin, driving their appetite higher. Those who sleep longer end up with less fat than those who are short-changed on the pajama time.

Our immune system takes a hit, too. Contrary to their name, natural killer lymphocytes, also known as NK lymphocytes, are the good guys. At least they wear white hats from our point of view, though that flu virus trying to establish a beachhead in your respiratory tract would not agree. Staying up until 3:00 am causes a 30 percent reduction in NK cells, with reduced function of those still present, resulting in increased susceptibility to colds, flu, and other infections.

Sleep and Mental Function

Remember the Pennsylvania researchers and their 1400 people from the phone book? Recall they gave these folks mental tests as well as sleep tests? When they ran the numbers on brain power, the results again surprised. People's perception of how they slept did not matter. What mattered was those six hours. Those who slept more, no matter how good or bad they were at judging their sleep quality, scored significantly higher on mental processing speed and short term visual memory. Further, a psychological test called "set-switching attention," a measure of executive function of the mind, improved. This suggests that those who sleep over six hours a night enjoyed greater over-all cognitive ability compared to a global slowing in those getting less sleep.

Sleep Tight

When you go to bed tonight, find a comfortable position and don't worry about sleeping. Unplug your reading lamp. Turn your clock to the wall and don't be concerned about the time. Just enjoy resting comfortably. You will be better prepared for the morrow with rest in bed rather than reading or getting up. Be lazy and let your mind wander freely. Take the attitude that you will naturally get as much rest as you need, even if you are not actually sleeping. You are in Nature's hands.

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Medicine for People! is published by Douwe Rienstra, MD at Port Townsend, Washington.