March 6, 2014 in Features

Ask Dr. K: Treating sleep apnea could lower blood pressure

Anthony L. Komaroff Universal Uclick

DEAR DOCTOR K: I’m a snorer. I read recently that treating snoring can affect blood pressure. Can you explain the connection?

DEAR READER: Severe snoring can be a sign of obstructive sleep apnea. If you have OSA, then your breathing is blocked temporarily several (sometimes hundreds) of times per night. What happens is that muscles in your upper airway (the back of the throat) relax too much. Normally, these muscles hold your airway open, so that air moves in and out of your lungs without obstruction.

When your breathing is blocked, oxygen levels in your lungs and blood start falling. Your brain sees this happening and causes adrenaline to surge into your bloodstream. This stimulates the breathing center in your brain: It’s a “Breathe now!” signal. You awaken briefly and gasp for air before falling back to sleep.

That’s bad enough. But surges of adrenaline also make your heart beat faster and raise your blood pressure. As a result, your blood pressure swings up and down.

A recent study in the Journal of the American Medical Association reported that treating OSA can help people with high blood pressure that’s difficult to control. In the study, researchers provided 12 weeks of the standard treatment for OSA to nearly 200 men and women with OSA and treatment-resistant hypertension.

The standard treatment was continuous positive airway pressure. With CPAP, you wear a mask that covers your nose. A small machine delivers continuous air pressure that prevents the collapse of your airway during sleep.

After 12 weeks of CPAP, average blood pressures were a few ticks lower. Study participants also had healthier nighttime blood pressure patterns. The improvements, though modest, are still important.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.

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