July 11, 2011 -- A common sleep disorder may affect the blood vessels responsible for supplying blood to the heart, raising the risk of heart disease in otherwise healthy people.
A new study is the first to show blood vessel abnormalities in otherwise healthy people with obstructive sleep apnea, a condition that causes periodic interruptions in breathing during sleep. Previous studies have linked sleep apnea to high blood pressure (hypertension) and other risk factors for heart disease.
Researchers found that treating obstructive sleep apnea with continuous positive airway pressure (CPAP) to reduce breathing interruptions during sleep reversed the blood vessel abnormalities. CPAP provides a consistent airflow that holds the airway open to prevent breathing interruptions during sleep.
“The findings should change how doctors treat patients with obstructive sleep apnea,” researcher Gregory Y.H. Lip, MD, professor of cardiovascular medicine at the University of Birmingham in the United Kingdom, says in a news release. “Even apparently healthy patients with sleep apnea show abnormalities of small and large blood vessels, as well as impaired blood supply to the heart muscle, and these can improve with CPAP therapy.”
In the study, published in Hypertension: Journal of the American Heart Association, researchers examined blood vessel function in three different groups of 36 people for a total of 108 participants.
The first group had moderate or severe obstructive sleep apnea without hypertension, the second group had hypertension without obstructive sleep apnea, and the third comparison group had neither hypertension nor obstructive sleep apnea.
Researchers assessed blood vessel function at the start of the study and again after the sleep apnea group received 26 weeks of CPAP therapy.
The results showed the hypertension and sleep apnea groups both had blood vessel abnormalities that impaired blood supply to the heart at the start of the study. They also found blood vessel abnormalities in larger blood vessels of the body.
Researchers found CPAP therapy improved blood vessel function tests and blood supply to the heart in the sleep apnea group.
The findings suggest treatment with CPAP may help prevent otherwise healthy people with obstructive sleep apnea from developing and dying from heart disease and related disorders.