Treating Women's Sleep Apnea May Lower Heart Death Risk
Study: Machine That Keeps Airways Open Is Linked to a Lower Risk of Heart Attack and Stroke Death
WebMD News Archive
Studying the Benefits of CPAP Treatment in Women continued...
Women with 10 to 29 breathing interruptions per hour were classified as having mild to moderate sleep apnea. Those with 30 or more interruptions per hour were told they had severe sleep apnea. Women who scored less than 10 were considered not to have sleep apnea and were used for comparison.
Every patient with severe sleep apnea was offered treatment with a CPAP machine that uses a pressurized flow of air to hold breathing passages open during the night. Women with mild to moderate sleep apnea were offered CPAP if they reported being sleepy during the day.
Counters on the machines told the researchers how long the women were using them at night.
During the study, 41 patients died of heart-related causes, including heart attacks and strokes and from heart failure.
Researchers discovered that women with severe, untreated sleep apnea -- meaning they didn’t use their CPAP machines, or used them for less than four hours a night -- had more than three times the risk of dying from a heart problem as women who didn’t have sleep apnea.
That was true even after researchers accounted for other things that influence the risk of heart disease, including age, body weight, high blood pressure, diabetes, and previous heart attacks or strokes.
Women with severe sleep apnea who used a CPAP machine for at least four hours a night saw no increase in their risk of heart or stroke-related death, however. They had the same risk as women who didn’t have sleep apnea.
“For patients with obstructive sleep apnea, adequate CPAP use is as important for their [heart] health as the pills they take for hypertension or diabetes,” researcher Francisco Campos-Rodriguez, MD, from the department of respiratory medicine at Valme University Hospital in Seville, Spain, says in an email to WebMD.
The retail cost of a CPAP machine runs from $400 to $800, but insurance plans may pick up the tab if it’s prescribed by a doctor.
Why Is Sleep Apnea Bad for the Heart?
Experts aren’t entirely sure why sleep apnea is so bad for the heart, but they have some working theories.
“There are two pathways through which it can worsen health. The first is through low oxygen, the second is through the frequent arousals,” says Pavlova.
But studies in animals have shown that interrupted breathing can lead to periods of low blood oxygen.
This low oxygen is thought to trigger the body’s fight-or-flight response, which raises blood pressure in the lungs and makes blood clot more easily, increasing the risk for events like heart attacks and strokes.
A second problem is that the body has to fight to breathe once the airway gets blocked.
“As a result of the strain to breathe, there is a response from the body to wake up, to take a better breath,” Pavlova says.