Treat Sleep Apnea, Lower Hard-to-Control BP?
Sleep apnea device allows normal breathing, reduces stress on body, study suggests
By Steven Reinberg
TUESDAY, Dec. 10 (HealthDay News) -- People with sleep apnea and hard-to-control high blood pressure may see their blood pressure drop if they treat the sleep disorder, Spanish researchers report.
Continuous positive airway pressure (CPAP) is the standard treatment for sleep apnea, a condition characterized by disrupted breathing during sleep. The sleep disorder has been linked to high blood pressure.
Patients in this study were taking three or more drugs to lower their blood pressure, in addition to having sleep apnea. Participants who used the CPAP device for 12 weeks reduced their diastolic blood pressure (the bottom number in a blood pressure reading) and improved their overall nighttime blood pressure, the researchers found.
"The prevalence of sleep apnea in patients with resistant [high blood pressure] is very high," said lead researcher Dr. Miguel-Angel Martinez-Garcia, from the Polytechnic University Hospital in Valencia.
"This [sleep apnea] treatment increases the probability of recovering the normal nocturnal blood pressure pattern," he said.
Patients with resistant high blood pressure should undergo a sleep study to rule out obstructive sleep apnea, Martinez-Garcia said. "If the patient has sleep apnea, he should be treated with CPAP and undergo blood pressure monitoring."
The report, published in the Dec. 11 issue of the Journal of the American Medical Association, was partly funded by Philips-Respironics, maker of the CPAP system used in the study.
The CPAP system consists of a motor that pushes air through a tube connected to a mask that fits over the patient's mouth and nose. The device keeps the airway from closing, and thus allows continuous sleep.
Sleep apnea is a common disorder. The pauses in breathing that patients experience can last from a few seconds to minutes and they can occur 30 times or more an hour.
As a result, sleep quality is poor, making sleep apnea a leading cause of excessive daytime sleepiness, according to the U.S. National Heart, Lung, and Blood Institute.
Dr. Gregg Fonarow, a spokesman for the American Heart Association and professor of cardiology at the University of California, Los Angeles, agrees that most patients with hard-to-control high blood pressure also suffer from sleep apnea.
"Close to three out of four patients with resistant [high blood pressure] have been found to have obstructive sleep apnea, and this sleep apnea may contribute to the difficulty to control the blood pressure in these patients," he said.
Although this study showed a benefit from CPAP in controlling blood pressure, questions remain about the treatment's overall effectiveness, Fonarow said.
"Whether these improvements in blood pressure can be sustained in the long term and will translate to improved health outcomes will require additional studies," he said.
According to the chief medical liaison for Philips Respironics, Dr. Teofilo Lee-Chiong, the CPAP device allows the patient to sleep, and thus lets the blood pressure drop normally as it would at night.