About 18 million Americans lose sleep every night because of sleep apnea, in which breathing sporadically stops during sleep. The disease has been linked to cardiovascular problems, and some studies have shown that people with sleep apnea are at higher risk of developing cardiovascular disease. Researchers in Ireland wondered whether the most common and effective treatment for sleep apnea, called continuous positive airway pressure therapy, which delivers air through a mask or pillow during sleep, affected the development of cardiovascular problems.

What the researchers wanted to know: Does a common therapy for sleep apnea also help treat cardiovascular disease?

What they did: The researchers followed 168 sleep apnea patients for about 7.5 years. Most of the patients, 107, were using continuous positive airway pressure therapy, though 61 patients had not used it for at least five years. The researchers looked at hospital records and sent the patients questionnaires to determine if they had either been diagnosed with or died from cardiovascular problems.

What they found: The group of patients treated with continuous positive airway pressure therapy had fewer instances of cardiovascular disease or death than the patients in the untreated group. Fewer patients getting treatment–31 percent versus 18 percent–were diagnosed with cardiovascular disease. Two people (1.9 percent) in the treated group versus nine (14.8 percent) in the untreated group died from cardiovascular problems.

What it means to you: Continuous positive airway pressure therapy could have benefits beyond just treating sleep apnea. Because there is some evidence that sleep apnea could increase a person's risk for heart problems, treatments that help the cardiovascular system as well as treat the apnea could be very beneficial.

Caveats: Patients were not randomly assigned in this study as they are in most clinical trials. However, their characteristics (gender, age, body-mass index etc) were generally the same. The researchers say they did not randomly assign people to treatment versus no treatment because, given the evidence that continuous positive airway pressure therapy is very effective, they felt it would have been unethical.

Find out more: The National Heart, Lung, and Blood Institute has a page describing sleep apnea and how it is treated.

The Mayo Clinic has a similar page.

Read the article: Doherty, L.S. et al. "Long-term Effects of Nasal Continuous Positive Airway Pressure Therapy on Cardiovascular Outcomes in Sleep Apnea Syndrome." Chest. June 2005, Vol. 127, No. 6, pp. 2076-2084.

Abstract online: http://www.chestjournal.org