March 23, 1999

Jumping ahead to Daylight Savings Time: Don't Forget National Sleep Debt, Wright State researcher says

DAYTON, OHIO—If you had to pick a poster boy for insomnia, whom would he be? Sleep researcher Michael Bonnet at Wright State University School of Medicine thinks of Don Knotts, the hyperkinetic comedian who played Deputy Barney Fife on television's "Andy Griffith Show." Barney Fife was always in motion. His "arousal controller" was set a little bit higher than normal. Bonnet believes that insomnia involves more complex processes than just the inability to sleep. He theorizes that we all have an "arousal controller" that enables us to maintain wakefulness. For most of us, the wakeful process balances a related process that lets us fall asleep. For chronic insomniacs, the processes are out of whack.

Bonnet's recent research supports his theory. His experiments found that people with chronic insomnia have a higher whole body metabolic rate -- 24 hours a day -- than those who sleep normally. The insomniacs had faster heart rates and higher body temperatures. "They're burning up more calories, using more oxygen, whether they're sleeping or awake," he explains. "Like Don Knotts, they're getting more input from the waking system than the sleeping system."

A professor of neurology at Wright State, Bonnet runs the sleep disorder clinic at the Dayton VA Medical Center. In addition to evaluating VA patients for clinical sleep problems, his research explores the physiological and behavioral mechanisms that put us to sleep and keep us awake. Over the past 20 years, he has been actively involved in the transformation of sleep disorder medicine from basic science research to a fully fledged medical specialty. Today most major hospitals have a sleep disorder clinic. "Everyone can relate to sleep," Bonnet says. "We spend a third of our lives doing it. But we still do not understand fully why we sleep, or what happens when we have problems sleeping. "Most of us can identify with the common problems associated with sleep," he continues. "Once in a while we've all experienced insomnia. Maybe we've had the experience of falling asleep at the wheel while driving, but we haven't had a car accident."

Sleep disorders take the common problems to a chronic level that can have serious consequences for an individual's health and the public's safety. In addition to investigating causes and cures for insomnia, sleep disorder research also involve studies of sleep apnea and the consequences of sleep deprivation. Sleep apnea is a pattern of sleep disturbance resulting from respiratory problems that can occur as frequently as once a minute, all night long, every night. People who experience sleep apnea do not notice that their sleep is disturbed. They say they sleep well at night, yet during the day they feel fatigued.

Bonnet simulated sleep apnea in experiments with college students who had normal sleep patterns. While they slept in laboratory bedrooms, their sleep was disturbed at varying time intervals throughout the night. Disturbance every 20 minutes had little effect on the students' alertness the next day. Disturbance every 10 minutes had a mild effect. Disturbance at 1-5 minute intervals had a significant effect on alertness. "Apparently there is some type of sleep unit. If you do not sleep undisturbed for periods longer than at least one minute, sleep will not do what it's supposed to do. There is some process going on in sleep that restores alertness," Bonnet explains. "Sleep disturbance once a minute would be very severe sleep apnea. It would leave you feeling just as sleepy as if you had not slept at all."

Sleep deprivation may sound like a form of psychological torture, but actually it's something many of us do every day -- voluntarily. As the pace of life accelerates, people do more and sleep less. As a nation we are chronically sleep deprived, according to Bonnet, who says we are racking up a "national sleep debt" that has significant consequences for society. "A hundred years ago there weren't many choices for things to do at night. Once it got dark, people went to bed," Bonnet says. "Today there are more and more choices. Sleep is a priority, but for most of us it's not the top priority. For some it's a very low priority. At some level we choose how much sleepiness we are willing to tolerate."

He cites some sobering facts. His own laboratory studies indicate that cutting normal nighttime sleep periods by 1.5 hours can reduce daytime alertness by one-third. Other studies have shown that up to one-third of normal adults experience sleep loss. Fatigue is a significant factor in 57% of accidents involving truck drivers and 10% of all fatal car crashes. The resulting cost to the economy exceeds $56 billion per year.

Public awareness about the consequences of voluntary sleep deprivation is growing, according to Bonnet. Support groups equivalent to MADD (Mothers Against Drunk Driving) have been organized by people who have lost loved ones to sleep-related accidents. Federal and state transportation departments are beginning to fund more sleep-related research. "We need to pay attention to the alertness function of sleep and the consequences of sleep deprivation with the same vigor that we now pay attention to the social consequences of alcohol abuse," he says.