Insomnia and Sleep-Disordered Breathing Link Raises Red Flag

Northbrook, IL - December 11, 2001

Can't sleep? Those long hours waiting for the sandman could mean something more than restlessness or difficulty winding down. In a new study published in CHEST, the peer-reviewed journal of the American College of Chest Physicians, sleep specialists found that one-half (50 percent) of patients being studied for sleep-disordered breathing (SDB) also had clinically meaningful insomnia complaints.

The study, conducted at the Sleep and Human Health Institute in collaboration with the University Hospital Sleep Disorders Center at the University of New Mexico, suggests that insomnia may very well indicate a more serious condition. "We usually picture insomnia and sleep-disordered breathing as distinct processes, but evidence indicates that in many cases both disorders are really two sides of the same coin," said study author Barry Krakow, MD, medical director at the sleep research institute in Albuquerque, NM. "This overlap seems to occur in many sleep disorders patients, which may need to prompt a shift in our thinking on how to evaluate and treat these patients."

According to a recent National Sleep Foundation survey, one-half of adults (51 percent) reported one or more symptoms of insomnia at least a few nights a week in the past year and about three in ten (29 percent) say they have experienced insomnia every night or almost every night. While the precise relationship between insomnia and SDB remains unclear, each of these sleep disorders may worsen the other disorder and thereby make treatment of both conditions more difficult and more complicated.

The study investigated 231 representative cases of SDB from a pool of 2,000, and surprisingly one-half were found to suffer also from insomnia. Each of the two groups -- SDB cases with or without insomnia -- showed no differences in age, sex or weight, and most patients were referred to treat sleep apnea or loud snoring.

However, nearly 20 percent of those with insomnia had not complained of snoring or apnea, yet still were diagnosed with SDB. Those with both SDB and insomnia reported significantly worse sleep: averaging more than one hour to fall asleep, sleeping less than six hours, and lying awake in bed for nearly an hour-and-a-half each night. They also reported more psychiatric disorders, cognitive-emotional symptoms, and physical and mental health symptoms that disrupted or prevented sleep, all of which are not generally expected in someone with SDB.

"Sleep studies looking for SDB are not routinely conducted on insomniacs," said Krakow, but in an accompanying editorial, Nancy Collop, MD, FCCP, a pulmonologist at the University of Mississippi Medical Center commented, "The findings from (this study) suggest this position may need review." Krakow speculates that, "this may be another example of the medical adage, 'you don't find what you don't look for.'"

The study also raises questions about the impact of insomnia on the treatment of SDB. "This study demonstrates the importance of physicians having proper training in sleep hygiene," said Sidney S. Braman, MD, FCCP, president of the American College of Chest Physicians. "Pulmonologists, primary care physicians, and mental health professionals, in addition to sleep medicine practitioners, must be able to distinguish insomnia patients with SDB from those without it. We need to be even more vigilant given today's managed care environment."

CHEST is a peer-reviewed journal published by the American College of Chest Physicians (ACCP). It is available online each month at www.chestjournal.org . ACCP represents more than 15,000 members who provide clinical, respiratory, and cardiothoracic patient care in the U.S. and throughout the world. ACCP's mission is to promote the prevention and treatment of diseases of the chest through leadership, education, research, and communication.