Pituitary News, Issue 18 - Winter 2001.

Sleep takes up about a third of our lives, and if we are not sleeping properly this seems to cause a big impact on our daily lives and our overall quality of life. Sleep problems in people with pituitary disorders are fairly common, and range from insomnia (difficulty initiating or maintaining sleep) to hypersomnia, or excessive sleepiness during the day.

Dr Sue Wilson
Psychopharmacology Unit, School of Medical Sciences, University of Bristol

What is normal sleep?

Normal sleep varies in amount from person to person, and there is no set length of sleep which is normal for everyone. However, most adults between the ages of 20 and 65 sleep for about 7-8 hours. If a recording of brainwaves is made we can see that sleep consists of several stages, ranging from very light 'dozing' to very deep sleep, which occur in a cyclical pattern throughout the night. Everyone has several short awakenings during the night, but these are often too short to be remembered, i.e. less than a minute or so. We wake more as we get older, and the awakenings get longer, so sleep becomes less 'efficient', as the amount of time we sleep as a proportion of the time in bed is reduced.

Why do we sleep when we do?

Three conditions need to be met before we can have a good night's sleep:

• it's bedtime on our 'body clock'
• it's an appropriate time since our last sleep (about 16 hours awake)
• our level of alertness, or arousal, is lowered

and of course, their converse should be met during the day when we want to be awake.

How can we help these processes?

If we're satisfied with our sleep we shouldn't need to do anything to change our usual routine, but if there's a problem, then there are some things we can do to optimise the sleep we have.

Our body clock consists of a small number of cells in a part of the brain near the pituitary, called the Hypothalamus, which govern the timing of lots of different body rhythms like rest-activity, hunger, hormones and many others. This clock is reset, or 'wound up' by various stimuli like light and exercise. When we get up in the morning, daylight entering through our eyes causes levels of the hormone melatonin to decrease sharply, and this results in a reflex rise 16 or so hours later which promotes sleep. We can reinforce this process by making sure that we always get up at the same time, about 16 hours before we want to sleep again, and that we get lots of daylight in the morning (not always easy in English winters!)

The second point, time since last sleep, is important because it means that in order to have a good length of time awake, we should not nap during the day. This is quite difficult to enforce, particularly in someone who has had a really bad night's sleep. People who are less mobile because of illness or disability are more likely to have problems keeping awake. We should learn to recognise the onset of sleepiness, and be aware that there are high risk times, such as after lunch. There are various strategies to use when that drowsy feeling comes over us, such as getting up from the chair and walking around, starting a difficult or very interesting task or getting some fresh air.

Devising a plan for combating this feeling will be a challenge and I would like to hear about successful and unusual ones.

The third condition, that of level of arousal or alertness, is one of the most difficult to deal with in people who can't get to sleep at night. Stress of various kinds, general day-to-day anxieties and particularly a 'worrying' nature will all contribute to general tension which manifests itself at bedtime. After a few bad nights, we begin to associate bed and bedroom with not sleeping, and this in turn increases our level of tension. The most successful strategy here is to acknowledge the stresses and anxieties, but to try and deal with them to some extent at a time well away from bedtime, such as just after the evening meal. Problems can be gone over, plans and lists can be made and then put away, so that if worrying thoughts come when it's time to sleep, we can say to ourselves that we've dealt with all that for today and nothing more can be done until the morning. Anxiety about sleep itself is very alerting, and the less we care about not sleeping the more likely we are to fall asleep. Clock-watching too is a very alerting activity, so put away that clock and do some relaxation exercises - there are some very good relaxation tapes on the market.

A summary of these 'sleep hygiene' tips is given at the end of this article. The best way of improving sleep is to follow all these tips and keep a diary of your sleep times - it makes it easier to see small improvements.

It may be that even after carefully doing all these things there are still problems with sleeping or problems staying awake in the daytime. This may be particularly so in some people with pituitary disorders, both before and after surgery. One of the reasons for this could be that there is changed function of the part of the hypothalamus which is intimately concerned with circadian (daily) rhythms, which is close to the pituitary. A more likely explanation is that the disruption in production and regulation of hormones is causing changes in alertness or biorhythms; thyroid hormones, Cortisol and Growth hormone all play a part in sleep-wake regulation. Some manipulation in the dose of hormone replacement may therefore be necessary or it may be that these people require drug treatment, either to get off to sleep or to remain awake, and specialist centres will recommend what sort of drug this might be.

Finally, there's nothing so reassuring as knowing that you're not the only one with a sleep problem, especially when you're lying awake in the small hours, or sleeping the day away. It is common, even more so in pituitary disorders, and in a high number of cases it can be fixed, so take heart and talk it over with your doctor.