(RxWiki News) High blood pressure affects millions of Americans, and having obstructive sleep apnea can make the condition worse. But treatment can make a difference.
A recent study found that using the most commonly prescribed treatment for obstructive sleep apnea improved patients' blood pressures over three months.
The treatment was CPAP, which stands for continuous positive airway pressure. CPAP treats sleep apnea, a condition in which a person frequently stops breathing or gets insufficient oxygen from breathing while asleep.
According to this study, participants who used CPAP experienced a lower average daily blood pressure and improved nighttime blood pressure.
"Treat your obstructive sleep apnea."
This study, led by Miguel-Angel Martinez-Garcia, MD, PhD, of the Respiratory Department at Hospital Universitario y Politécnico La Fe in Spain, looked at whether the use of CPAP affected blood pressure in patients with sleep apnea.
The researchers compared two groups of patients who had ongoing high blood pressure and had been diagnosed with obstructive sleep apnea.
The 194 patients who participated all had an apnea-hypopnea index (AHI) of at least 15. The average AHI among the group was 40.
The AHI score a person receives represents the number of times that they stop breathing for at least 10 seconds or that they breathe so shallowly that they arouse or experience a drop in blood oxygen saturation levels.
An AHI score between 5 and 15 means the adult has mild obstructive sleep apnea, a score of 15 to 30 is moderate, and more than 30 is severe.
One group of 98 patients was randomly assigned to use CPAP, which involves wearing a mask that delivers pressurized air to a person's airways while they are asleep.
The other group of 96 patients did not use CPAP and served as a comparison group.
Participants in both groups continued taking their blood pressure medications. The average participant in the study was taking 3.8 medications to control blood pressure.
After three months, the researchers compared the average daily blood pressure of individuals in both groups.
At the start of the study, the average blood pressure of the group had been a systolic (top number) of 144 mm Hg and a diastolic (bottom number) of 83 mm Hg.
A typical normal blood pressure is a systolic reading of 120 mm Hg or lower and a diastolic reading of 80 mm Hg or lower.
Among the CPAP group, 72 percent of the patients used CPAP for at least four hours or more per day. CPAP is recommended to be used any time a person with obstructive sleep apnea is asleep.
The researchers found that the patients using CPAP had a greater decrease in their diastolic blood pressure than those not using CPAP.
The average daily blood pressure for those using CPAP was an average 3.2 mm Hg lower than that of participants not using CPAP.
The researchers did not observe any significant differences in the average daily systolic blood pressure between the groups.
However, the researchers did observe another pattern among those using CPAP related to their nighttime blood pressure.
At the start of the study, 26 percent of the overall patients experienced at least a 10 percent decrease in their blood pressure at night, compared to their daytime blood pressure.
After the three months of the study, those experiencing this nighttime decrease included 36 percent of the CPAP participants but only 22 percent of the non-CPAP participants.
The researchers calculated that the participants using CPAP had twice the odds of experiencing a nighttime decrease in blood pressure of at least 10 percent, compared to those not using CPAP.
In addition, the more hours the participants used CPAP, the greater their decrease in daily average blood pressure was.
The researchers concluded that using CPAP consistently over three months resulted in a decrease in daily average blood pressure, as well as improvements in individuals' nighttime blood pressure.
This finding matches up with clinical experience, according to William Kohler, MD, the medical director of the Florida Sleep Institute in Spring Hill, Florida.
"I've had patients with difficult-to-treat hypertension who have sleep apnea and are treated effectively with their CPAP who will have improvement in their blood pressure," Dr. Kohler said.
"There are numerous causes for elevated blood pressure," he said. "If the sleep apnea is one of the primary causes, the patient often can have a decrease in their medications or actually get off their medications completely, as I've found in a number of cases in my patients."
He said it's important to explore sleep apnea as a possible condition in those with high blood pressure.
"The bottom line is if you have difficult-to-control hypertension, you need to evaluate for the possibility of sleep apnea and then treat it effectively," Dr. Kohler said.
This study was published December 10 in the journal JAMA. The authors declared no conflicts of interest.
The research was funded by Philips-Respironics, Sociedad Española de Neumología, Instituto de Salud Carlos III and Sociedad Valenciana de Neumología.