It's the snoring, gasping, and coughing that can keep you up at night and leave you exhausted during the day. Obstructive sleep apnea, periods during sleep where breathing stops for 10 to 20 seconds, keeps nearly 1 in 5 Americans from sleeping well. However, there is a stereotype, even among doctors, that older, overweight men are the only people who suffer from sleep apnea. Scientists from the University of Wisconsin set out to debunk that myth.

What the researchers wanted to know: Who is at greatest risk for sleep apnea?

What they did: The researchers compiled data from numerous studies that looked at who is at risk for sleep apnea. They examined both the demographic characteristics of people who develop the condition and the factors, such as genetics or smoking, that might put people at higher risk. Finally, the researchers analyzed which diseases are most often associated with sleep apnea.

What they found: Sleep apnea can strike anyone but occurs about twice as often in men, and risk increases with age. However, women with the condition are less often diagnosed than men, especially if they have mild or early stage sleep apnea. People who are overweight are also at greater risk, and though there's been talk about whether obesity causes apnea, the scientific jury is still out on that. Genetics, facial and skull structure, and menopause also seem to put people at higher risk. In addition to making you sleepy on the job, the researchers found strong links between apnea and diabetes, high blood pressure, and heart disease. Separate studies have found that patients with these other conditions often had sleep apnea, and that sleep apnea could make some conditions worse.

What it means to you: Sleep apnea is often first noticed by a family member, spouse, or anyone you regularly share a bed with. The key signs are a loud snort or choke during sleep, which happens after the person starts breathing again. If you are often drowsy during the day, or feel that your sleep is not restful, you might want to talk to your doctor about sleep apnea. The good news is that the condition is not difficult to treat–some people will just need to change some of their habits, such as avoiding alcohol before bed. The more severe cases will require more extensive measures, but surgery is usually not necessary.

Caveats: The authors fault previous studies on sleep apnea for perpetuating the stereotype that the condition affects only older, overweight men. However, they then go on to use some of these same studies to draw their own conclusions about who is at risk.

Find out more: The National Heart, Lung, and Blood Institute has a good explanation of sleep apnea with pages on symptoms and treatments.

Read the article: Young, T., Skatrud, J., and Peppard, P.E. "Risk Factors for Obstructive Sleep Apnea in Adults." Journal of the American Medical Association. April 28, 2004, Vol. 291, No. 16. pp. 2013-2016.

Abstract online: http://jama.ama-assn.org