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.