In a nutshell
This study examined the effects of continuous positive airway pressure (CPAP) treatment and supplemental oxygen on blood pressure in patients with obstructive sleep apnea. The authors concluded that treatment with CPAP but not supplemental oxygen was associated with a significant reduction in blood pressure.
Obstructive sleep apnea (OSA) is when the airways become completely or partially blocked during sleep. The symptoms of OSA include snoring, night sweats, and waking up with a dry mouth or sore throat. This condition can reduce the flow of oxygen to the organs and may lead to an irregular heartbeat, which can result in elevated blood pressure.
OSA is an established cause of hypertension. Patients with hypertension have a higher resting blood pressure than the body needs. The blood pressure needs to be lowered to avoid cardiovascular complications such as heart attacks, strokes, and heart failure. Continuous positive airway pressure (CPAP) is a common treatment for OSA. This treatment involves the patient receiving mild air pressure continuously from a ventilator to keep the airways open. Supplemental oxygen can be given at night from a tube into the nose as a less intrusive treatment for sleep apnea. It is not clear if this can effectively reduce blood pressure in OSA patients.
Methods & findings
281 patients with moderate to severe OSA were included in this study. Patients were randomly assigned into one of 3 groups. The control group were educated on sleep hygiene and healthy lifestyles. The second group also received the same education and received CPAP treatment during night time. The third group were given the same education and received supplemental oxygen at night. Blood pressure was measured before and 12 weeks after treatment.
After 12 weeks, the average 24-hour blood pressure of the CPAP group was 2.4 mm Hg lower compared to the control group, and 2.8 mm Hg lower compared to the supplemental oxygen group. No significant differences in average blood pressure were observed between patients receiving supplemental oxygen and patients in the control group.
Age, gender, ethnicity, body fat measures, severity of sleep apnea, and use of blood pressure treatments had no effect on these results. The number of hours of CPAP use also did not affect the results. CPAP treatment was associated with significantly lower levels of proteins involved in inflammation than the control group.
There were no significant differences between groups for the number of side effects experienced.
The bottom line
The authors concluded that treatment with CPAP but not supplemental oxygen was associated with a significant reduction in blood pressure in patients with moderate to severe OSA.
Published By :
The New England Journal of Medicine
Jun 12, 2014