Positive airway pressure therapy reduces arterial tone, improves endothelial function

CHICAGO — Young and middle-aged patients with obstructive sleep apnea who are treated with positive airway pressure therapy may also see reduction in arterial tone and improvement in endothelial and diastolic function, according to data presented at the American College of Cardiology Scientific Session.

The researchers conducted a prospective, interventional study on the CV effects of positive airway pressure therapy and withdrawal in patients with normal BP. Eighty-four patients (77% men; mean age, 41 years) received overnight polysomnography or home sleep testing to determine their apnea-hypopnea index. At baseline, patients had a central aortic systolic BP of 115 mm Hg, a diastolic BP of 76.6 mm Hg and moderate to severe obstructive sleep apnea with a mean apnea-hypopnea index of 39.8 events/hour.

The results were simultaneously published in the Journal of the American Heart Association.

According to the researchers, central systolic BP was 2.6 mm Hg lower at 4 weeks (P = .008) and 2.9 mm Hg lower after 12 weeks (P = .003). In addition, decreases in diastolic BP and mean BP (P < .001 for both), as well as in augmentation index (P < .001), peripheral pulse wave velocities (P = .003) and brachial artery dilation (P < .001), also were observed. By 12 weeks, there also were improvements in left ventricular diastolic function, systemic and pulmonary vascular resistance (P < .004 for all).

After adjustment for risk factors, positive airway pressure therapy was associated with reductions in diastolic BP (P = .045), augmentation index (P = .049) and peripheral pulse wave velocities (P = .007), as well as improvement in brachial artery flow-mediated dilation - a measure of endothelial function (P = .015).

The researchers examined the effect of positive airway pressure therapy withdrawal in a subgroup of 44 patients. After 1 week without therapy, the patients experienced an increase in brachial diameter, diastolic BP, mean BP, augmented index and heart rate (P < .05 for all).

“Our results highlight the need for future longitudinal studies that assess the effects of early detection and treatment of moderate-to-severe CEK1 obstructive sleep apnea before the development of clinical hypertension to evaluate whether positive airway pressure compliance can prevent the future CV complications associated with the disease,” the researchers wrote. – by Tracey Romero

References:

Korcarz C, et. al. Poster 1190-367. Presented at: American College of Cardiology Scientific Session; April 2-4, 2016; Chicago.

Korcarz C, et al. J Am Heart Assoc. 2016; doi:10.1161/JAHA.115.002930.

Disclosure: The researchers report no relevant financial disclosures.