Sleep Deprivation

There are many reasons for sleep deprivation. Each year, there are about 40 million people in the United States who suffer from sleeping disorders. An additional 20 million have occasional sleeping problems, according to the National Institute of Neurological Disorders and Stroke.

Dr. Jeffrey Hausfeld, M.D., adjusts a Continuous Positive Airway Pressure (CPAP) device for his patient. The CPAP device treats obstructive sleep apnea by delivering continuous air pressure through the nasal passages to keep the upper airway open.People who work nights, for example, probably never completely adapt because our bodies want to be awake during the day and asleep at night. We are governed by the circadian rhythm, an internal clock that regulates sleep and wake cycles. Sleep deprivation can also result when people choose to skimp on sleep in favor of work, parties or late-night television.

Whatever the reason for sleep loss, research has shown that it takes a toll on us both mentally and physically. While we sleep, our bodies secrete hormones that affect our mood, energy, memory, and concentration. Testing has shown that with a driving simulator or a hand-eye coordination task, sleep-deprived people may perform just as badly as intoxicated people.

Sleep deprivation and fatigue have long been issues for professions that have traditionally held long work hours. Pilots have federal regulations that limit their work hours to eight hours of flying time within a 24-hour period. Truck drivers can't drive more than 10 hours without a mandatory eight-hour break. Physician advocacy groups are pushing for the passage of the Patient and Physician Safety Protection Act, currently under consideration in Congress, that would set limits nationwide on the number of hours worked by medical residents.

According to the American Medical Student Association, residents sometimes work 100-120 hours a week in 24- and 36-hour shifts. Some have reported making mistakes with medication, falling asleep while driving home, and experiencing health problems, such as depression. The bill would limit residents to 80 hours per week with at least 10 hours off between shifts, among other provisions.

Recent research suggests that if sleep deprivation is long-term--whether because of lifestyle choices or sleep disorders--it may increase the severity of age-related chronic disorders such as diabetes and high blood pressure. In a study published in the Oct. 23, 1999, issue of The Lancet, Eve Van Cauter, Ph.D., professor of medicine at the University of Chicago, led researchers who restricted 11 young men to four hours of sleep for six nights, and then recorded their bodily functions. The researchers then allowed the same young men to spend 12 hours in bed per night for six nights, and compared their bodily functions to those recorded earlier. The researchers found negative effects on metabolic and endocrine functions when the men were sleep-deprived similar to those seen in older people as a result of normal aging.

In another study, published in the Sept. 25, 2002, issue of the Journal of the American Medical Association, Van Cauter and colleagues found a marked decrease in the response to flu vaccination in young, healthy people who were immunized after four days of sleep restriction, compared with those whose sleep was unrestricted.

"There's a need to look at sleep on the same level of importance as diet and exercise," says Carl Hunt, M.D., director of the National Center on Sleep Disorders Research, part of the National Heart, Lung, and Blood Institute. "All three are equally important for good health."