How sleep apnea increases the risk of stroke-related death

Washington, January 7 (ANI): Scientists at the Yale University School of Medicine in New Haven, Connecticut, say that obstructive sleep apnea decreases blood flow to the brain, elevates blood pressure within the brain, and eventually harms the brain's ability to modulate such changes and prevent damage to itself.

Reporting their observations in the Journal of Applied Physiology, they said that their findings might prove helpful in understanding why people with sleep apnea are more likely to suffer strokes and to die in their sleep.

Sleep apnea is the most commonly diagnosed condition amongst sleep-related breathing disorders, which can lead to debilitating, and sometimes fatal, consequences.

Researchers Fred Urbano, Francoise Roux, Joseph Schindler, and Vahid Mohsenin say that their current study identifies a mechanism behind stroke in patients diagnosed with sleep apnea.

During sleep apnea episodes, the upper airway becomes blocked, hindering or stopping breathing and causing blood oxygen levels to drop and blood pressure to rise.

People suffering this eventually awaken, and begin breathing so as to restore normal blood oxygen and blood flow to their brains.

Generally, the brain regulates its blood flow to meet its own metabolic needs, even in the face of changes in blood pressure -- a process known as cerebral autoregulation.

The researchers say that their study has shown that the repeated surges and drops in blood pressure and blood flow during numerous apnea episodes each night reduces the brain's ability to regulate such functions.

Dr. Mohsenin and his colleagues have already shown in a previous study that sleep apnea patients are three times more likely to suffer a stroke or die, compared to people in a similar state of health but without this condition.

"After we found that sleep apnea is a risk factor for stroke and death, independent of other risk factors, we hypothesized that there must be something wrong with the regulation of blood flow to the brain," he said.

His team has now found that repeated surges and drops in blood pressure and low oxygen levels eventually impair the body's ability to regulate blood flow to the brain.

Dr. Mohsenin also warns that sleep apnea may occur over a long period of time before the person becomes aware of it and seeks medical treatment. Here are the symptoms Dr. Mohsenin says to watch out for:

He suggests that those being treated for sleep apnea remain compliant with treatments. (ANI)