MADISON, Wis. -- When women complain of daytime sleepiness and snoring, doctors may not automatically think of sleep apnea, as they ordinarily do with men, suggests a University of Wisconsin Medical School study. Published in the current issue of Archives of Internal Medicine, the study showed that women with sleep apnea have the same standard symptoms as men do. The finding hints at another explanation for why many more men are diagnosed with the disorder than women.

"Health care providers may not be asking the right follow-up questions or prescribing additional tests when women come to them with these symptoms, which are automatically associated with sleep apnea in men," said UW Medical School professor of preventive medicine Terry Young, Ph.D. "This may explain why sleep disorder clinics are filled predominantly with men, even though we have found that at least a quarter of the people with sleep apnea are women."

Sleep apnea consists of episodes of breathing pauses during sleep that may lead to other health problems, including hypertension.

In 1993, Young reported in the New England Journal of Medicine that many more women than previously expected experience breathing disorders related to sleep apnea. She and her colleagues noted a male-to-female ratio of 3 to 1, much different than the 10 to 1 ratio usually seen in sleep clinics.

The observation came from the Sleep Cohort Study, an on-going population-based investigation of cardiopulmonary problems linked to sleep disorders. Approximately 1,200 randomly selected Wisconsin state employees have been studied so far in an overnight stay at the General Clinical Research Center of the University of Wisconsin Hospital and Clinics.

In the current study, the UW researchers sought to learn if fewer women were diagnosed with sleep apnea because they had different symptoms than men. Participants consisted of 551 men and 388 women between the ages of 30 and 60 randomly selected for an overnight study.

"We hypothesized three possible explanations for the gender disparity in sleep apnea diagnosis," said Young. "Women could be embarrassed to report they snore, they might have different symptoms than men, or doctors might not link sleep apnea in women to snoring and daytime sleepiness, as they do with men."

The study revealed that women with various levels of sleep apnea did not experience symptoms that differed significantly from those in men with the same apnea levels. What's more, women showed no reluctance to admit they snored.

"The most viable explanation for the disparity is that health care providers are not taking women seriously when they complain of these symptoms," said Young. "This may be true particularly when women report psychological problems such as depression at the same time as they describe sleepiness and snoring."

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