Kathy

Source: University Of Pittsburgh Medical Center

ScienceDaily: Posted 6/25/98

Deterioration Of Sleep During Middle Age Related To Changes In The Biological Clock, Say Pitt Researchers

In one of the first studies of its kind, sleep researchers at the University of Pittsburgh have learned that quality of sleep begins to
deteriorate during what many consider the most productive years -- middle age -- much earlier than previously thought, said
Julie Carrier, Ph.D., who present her findings at the 12th Annual Meeting of the Associated Professional Sleep Societies in
New Orleans, Tuesday, June 23.

This finding is important because it affects a significant number of middle-aged people, who comprise the majority of the work
force, said Dr. Carrier.

"Middle age is a turning point for sleep. Some sleep patterns have already changed significantly by the time an average adult
reaches age 30. Though these changes may go unnoticed at first, they may over time become a problem," said Dr. Carrier,
post-doctoral fellow, department of psychiatry, University of Pittsburgh School of Medicine.

Dr. Carrier and her colleagues tracked sleep patterns in 110 healthy study volunteers 20 to 59 years of age, and found that
sleep changed dramatically between the 20s and the 50s. They found that, with age, people go to bed and get up earlier, sleep
less, wake up more during the night, have more light stages of sleep and fewer deep stages.

Many of these gradual changes in sleep are most likely tied to age-related changes in features of the biological clock, a system
that regulates the sleep/wake cycle, alertness and body temperature, said Dr. Carrier. The biological clock regulates the timing
of our psychological and physiological functions so that they are in tune within the individual and with the environment. For
example, it will tell your body when it is time to go to bed and when it is time to be awake. In order to work well, the biological
clock should send a strong signal at the right time. This mechanism is so important that disruptions, such as those caused by
cross-time zone travel or shift work, can cause sleep problems that can lead to poor performance at work and even a higher
risk of accidents.

"We need to learn where the system breaks down," explained Dr. Carrier. "Middle-aged people are a significant segment of the
population who need to be alert and productive, so good sleep is essential. Now we are learning that as we age, we become
less able to work shifts or handle jet lag, a big problem for industrial workers or those who must travel frequently for their jobs.
If we are able to find out what is causing the biological clock to change with age, we may be able to discover ways to
overcome these changes and help get these people back on track."

Dr. Carrier will receive the Young Investigator Award from the Sleep Research Society at this week's 12th Annual Meeting of
the Associated Professional Sleep Societies for her work on this study. Co-authors from the Sleep and Chronobiology Center,
Western Psychiatric Institute and Clinic, are Timothy H. Monk, Ph.D.; Daniel J. Buysse, M.D.; and David J. Kupfer, M.D.