LOS ANGELES – Researchers at the University of California, Los Angeles, found that the body’s autonomic responses that control blood pressure, heart rate, and sweating are weaker in people with obstructive sleep apnea, but even more diminished in women.
As reported in the UCLA Newsroom, the new study from the UCLA School of Nursing includes some stern warnings. “We now know that sleep apnea is a precursor to bigger health issues,” said Paul Macey, lead researcher on the study, which appeared last week in the peer-reviewed journal PLOS ONE. “And for women in particular, the results could be deadly.”
UCLA Newsroom reporter Laura Perry points out that sleep apnea affects more that 20 million adults in the U.S. “and is associated with a number of serious health consequences and early death. Women are much less likely to be diagnosed than men.”
For the study, men and women, both with and without obstructive sleep apnea, had their heart-rate responses measured during three physical tasks:
• The Valsalva maneuver: Subjects breathe out hard while the mouth is closed.
• A hand-grip challenge: Subjects squeeze hard with their hand.
• A cold pressor challenge: A subject’s right foot is put in almost-freezing cold water for a minute.
In all three tests, changes to the normal heart rate were lower and delayed in patients with obstructive sleep apnea, compared with healthy controls. The researchers found that the difference was even more pronounced in women.
“The heart-rate results for these tests show that the impact of sleep apnea, while bad in men, is more severe in women,” Macey said. “This may mean that women are more likely to develop symptoms of heart disease, as well as other consequences of poor adaptation to daily physical tasks. Early detection and treatment may be needed to protect against damage to the brain and other organs.”
The next step in the research is to see if the autonomic responses improve with treatments such as CPAP. Researchers also intend to investigate the affect of other treatments. The study was funded by the National Institutes of Health and the National Institute of Nursing Research.