Snoozing soundly staves off the big sleep. (Bad Sleepers Hurry Death).

For many people, a good night's sleep is rare. Surveys indicate that around one in three older adults, ages 55 and up, experiences chronic insomnia or other sleep disturbances. The news gets worse.

Among a group of healthy elderly people tracked for an average of 13 years, those who had difficulty falling or staying asleep died from natural causes at a much higher rate than those who slept well, according to a report in January/February Psychosomatic Medicine.

If the results hold up, researchers will need to examine whether medications and behavioral treatments for insomnia boost survival in the elderly, say study leader and psychologist Mary A. Dew of the University of Pittsburgh School of Medicine and her colleagues.

In an investigation going back to 1984, the researchers studied 186 elderly adults, most between 60 and 80 years old, who had never exhibited mental disorders, significant sleep disturbances, or any marked declines in thinking and memory. None took sleep-altering medications. As part of the study, each participant underwent brain wave monitoring during sleep for one or two nights in a sleep laboratory.

Between 4 and 19 years after entering the study, 66 volunteers had died, primarily from cancer, heart disease, and pneumonia. Of that number, 38 percent had taken longer than 80 minutes to fall asleep in the lab and 51 percent had lost substantial sleep due to nighttime awakenings. Among the surviving 120 participants, 19 percent and 31 percent, respectively, had displayed those sleep problems.

A less pronounced, but statistically notable, death-rate increase occurred for participants who had exhibited an unusually high or low percentage of rapid eye movement (REM) sleep.

The disparities in sleep-related problems between the group that died and the surviving group could not be explained by age, sex, or physical condition of volunteers upon entering the study, Dew and her colleagues report.

"[Sleep disturbances] are increasingly being implicated as predictors of mortality, especially in older adults," comments psychiatrist and sleep researcher Michael Irwin of the University of California, Los Angeles.

Sleep problems may hasten death in any of several ways. For instance, Irwin has reported associations between sleep disturbances and immune system impairments. Other data tie sleep disorders to an increased risk of dying from heart disease and to neurotransmitter disturbances that may contribute to brain disease.

It's also possible that sleep apnea, disorganized circadian rhythms, and undetected, early stages of progressive brain diseases contributed to deaths in her team's study, notes Dew.

The new findings shouldn't send people running to their physicians for sleeping-pill prescriptions, Irwin says. To sleep better, he first advises going to bed and waking up at regular times, exercising daily, and limiting alcohol use.