Resistant Hypertension Responds to Apnea Treatment
Twelve weeks of continuous positive airway pressure decreased 24-hour mean and diastolic BP.
Individuals who suffer from obstructive sleep apnea and have high blood pressure (BP) that cannot be controlled with fewer than three medications may be able to address both conditions with continuous positive airway pressure (CPAP) therapy.
More than 70% of people with resistant hypertension have obstructive sleep apnea, and CPAP treatment may reduce blood pressure, but the effect of CPAP therapy on BP in patients with resistant hypertension has not been well-studied. CPAP treatment, which is commonly administered to manage obstructive sleep apnea, a machine delivers mild air pressure through a mask worn during sleep to help keep the person's airways open.
Now, Miguel-Angel Martinez-Garcia, MD, PhD, of the Hospital Universitario y Politecnico La Fe, in Valencia, Spain, and colleagues have found that 12 weeks of CPAP treatment reduced 24-hour mean and diastolic BP and improved the nocturnal BP pattern in patients with resistant hypertension and an apnea-hypopnea index of 15 or higher.
In the clinical trial, reported online ahead of print in Journal of the American Medical Association, Martinez-Garcia's team randomized 194 patients throughout 24 teaching hospitals in Spain to CPAP or no therapy. All patients continued using their usual antihypertensive medications (mean 3.8 medications). Approximately three-fourths (72.4%) of the patients assigned to CPAP underwent the treatment for at least four hours per day.
Baseline 24-hour mean BP was 103.4 mm Hg; systolic BP, 144.2 mm Hg; and diastolic BP, 83 mm Hg. Nearly 26% of patients displayed a dipper pattern (a decrease of at least 10% in average nighttime BP compared with the average daytime BP at baseline. The mean apnea-hypopnea index was 40.4.
Data were collected from June 2009 to October 2011. After 12 weeks of treatment, the 98 patients in the CPAP group achieved a greater decrease in 24-hour mean BP (3.1 mm Hg) and in 24-hour diastolic BP (3.2 mm Hg), but not in systolic BP compared with the 96 patients in the control group. In addition, 35.9% of the CPAP users exhibited a nocturnal BP dipper pattern at the 12-week mark compared with just 21.6% of the control group.
The investigators noted significant positive correlation between hours of CPAP use and the decrease in 24-hour mean BP and systolic and diastolic BP.