Sleep Apnea: Nighttime Breathing Mask Decreases Blood Pressure In People

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Nighttime Breathing Mask Decreases Blood Pressure In People With

Sleep Apnea

http://www.medicalnewstoday.com/medicalnews.php?newsid=43859

Patients with the nighttime breathing disorder known as obstructive

sleep apnea who receive air through a mask while they sleep can

significantly reduce their blood pressure, according to a study to be

presented at the American Thoracic Society International Conference

on May 22nd.

" Sleep apnea can have significant consequences on a person's physical

health, and this study shows once again that treatment may lessen

those risks, " said lead researcher Norman, M.D., Fellow in

Pulmonary and Critical Care at the University of California San Diego

Medical Center.

In obstructive sleep apnea, the upper airway narrows, or collapses,

during sleep. Periods of apnea end with a brief partial arousal that

may disrupt sleep hundreds of times a night. More than half of those

with sleep apnea also have high blood pressure, and their blood

pressure does not fall during sleep as it does in most people.

The most widely used treatment for sleep apnea is a technique called

nasal CPAP, for continuous positive airway pressure, which delivers

air through a mask while the patient sleeps. It has proved successful

in many cases in providing a good night's sleep and preventing

daytime accidents due to sleepiness. Supplementary oxygen is

sometimes used as a treatment for sleep apnea.

The researchers studied 46 patients with moderate to severe sleep

apnea. They were randomly assigned to receive either CPAP treatment,

fake CPAP or supplemental nighttime oxygen through a face mask. All

patients were hooked up to a 24-hour ambulatory blood pressure

monitor, which consists of a small machine strapped to the patient's

torso that attaches to an arm cuff. The cuff automatically inflates

and deflates to measure patients' blood pressure.

After two weeks, patients who received the real CPAP treatment had

significant reductions in blood pressure during the day and night.

Nighttime oxygen therapy did not affect blood pressure.

" There has been some controversy over how sleep apnea causes elevated

blood pressure, " Dr. Norman said. " Doctors don't know if it is due to

drops in oxygen levels or arousals from sleep. Our study indicated

that correcting drops in oxygen levels alone may not be enough to

reduce blood pressure. "

The National Heart, Lung, and Blood Institute estimates that 18

million Americans have sleep apnea. Men are more susceptible than

women.