Women Differ From Men; Sleep Disorder Breathing Noted

Northbrook, IL - November 13, 2001

Women have lower incidence of sleep apnea than men due to their physical make-up. A study published in the November edition of CHEST, the peer-reviewed journal of the American College of Chest Physicians, found that even though women had higher body mass indexes and smaller throat size than men, they had less severe obstructive sleep apnea (OSA). The gender differences in the expression of sleep-disordered breathing (SDB) were found to be due in large part to upper airway tissue characteristics rather than control of airway muscles.

Compared with men, women have greater total body fat and are more obese, however, despite similar clinical presentation of snoring and excessive daytime sleepiness, women had milder OSA. We have known for some time that women have far less apnea during sleep than men, said study author Vahid Mohsenin, MD, associate professor of medicine at Yale University School of Medicine and associate fellow at The John B. Pierce Laboratory. But the expression of SDB in this study suggests inherent structural and functional differences between men and women, underscoring the role that gender plays in the physical manifestation of sleeping difficulties.

The study, conducted on 78 male patients and 52 female patients, found that airflow limitation in men is due to more compliant upper airways, more pronounced reduction in the pharyngeal caliber in supine position, and greater inspiratory pressure during sleep. Upper airway resistance in female patients changes little during sleep with no significant decrease in inspiratory intraluminal pressure, suggesting a more unobstructed airflow.

The study also found that the pharyngeal size is an important determinant of OSA in men but not in women.

CHEST is a peer-reviewed journal published by the American College of Chest Physicians (ACCP). 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.