APPLES - a Ground Breaking Sleep Apnea Study looks at Efficacy of CPAP Treatment

Stanford, CA - July 27, 2005

If asked to name the most common chronic illness in the United States, sleep apnea probably wouldn't be the first thing to pop into your head. Yet according to well-known sleep expert William Dement, MD, PhD, no other chronic disease afflicts more Americans than apnea - a potentially fatal disorder in which people stop breathing sometimes hundreds of times a night for up to a minute each time.

Dement and his colleagues at Stanford University School of Medicine are now recruiting patients for a clinical trial on a treatment for the disease, which affects 4 percent of men and 2 percent of women between the ages of 30 and 60. Known as APPLES - Apnea Positive Pressure Long-Term Efficacy Study - the multi-center study is the largest clinical trial for a sleep disorder ever funded by the National Institutes of Health.

The most common type of sleep apnea is obstructive sleep apnea, in which soft tissue at the back of the throat collapses and obstructs the airway. The lack of oxygen eventually rouses the sleeper slightly, enough to open the airway, but the cycle repeats itself as the patient resumes deeper sleep.

Symptoms of sleep apnea include daytime sleepiness, loud snoring and choking noises during sleep. Untreated sleep apnea has been linked to fatigue, high blood pressure, stroke and a decline in cognitive functions.

Apnea treatment typically involves a special device that gently blows air into a patient's nose through a mask, preventing the airway from closing. Clete Kushida, MD, PhD, associate professor of psychiatry and behavioral sciences, calls the device - known as the nasal continuous positive airway pressure, or CPAP - the most effective, noninvasive method of treating apnea.

Researchers want to learn more about the treatment, and APPLES will investigate the long-term effects of CPAP. Preliminary studies conducted at Stanford have been promising: consistent use of active CPAP caused patients to be more awake during the day, perform better on memory tests and score higher on a questionnaire about their quality of life.

"The data in our pilot study were convincing enough to apply for this special grant," said Kushida, who hopes to see similar results in the new study.

During the study, participants use a CPAP device for six months. Half receive active CPAP and half use a sham system. The researchers assess patients' sleepiness, mood, quality of life and ability to think over the course of the study.

Participation lasts seven months and includes two training session, several overnight sleep studies, three days of testing and two physician appointments. Participants receive $500 upon conclusion of the study.

The five-year study includes a total of 1,100 patients. Other sites include the University of Arizona , Harvard University , St. Luke's Hospital in St. Louis and St. Mary's Medical Center in Walla Walla , Wash. The industry partners are SAM Technology and Respironics, Inc.

APPLES volunteers must be age 18 or older and have no other sleep disorders. Those interested in participating in APPLES should call (650) 736-8871 or e-mail ronelleb@stanford.edu.