People with sleep apnoea and hard-to-control high blood pressure may see their blood pressure drop if they treat the sleep disorder, Spanish researchers report.
Patients in this study were taking three or more drugs to lower their blood pressure, in addition to having sleep apnoea. 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 night-time blood pressure, the researchers found.
“The prevalence of sleep apnoea 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 apnoea] 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 apnoea, Martinez-Garcia said. “If the patient has sleep apnoea, he should be treated with CPAP and undergo blood pressure monitoring.”
The report, published in the 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.
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 apnoea.
“Close to three out of four patients with resistant [high blood pressure] have been found to have obstructive sleep apnoea, and this sleep apnoea 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.