Obstructive sleep apnea and blood pressure. Interaction between the blood pressure-lowering effects of positive airway pressure therapy and antihypertensive drugs.

Background: There is increasing evidence that obstructive sleep apnea is an independent risk factor for arterial hypertension. Previous studies on the antihypertensive effects of positive airway pressure therapy on daytime blood pressure (BP) revealed inconsistent results.

Methods: The relations between the apnea/hypopnea index (AHI) and BP or heart rate (HR) were investigated in a cohort of 540 consecutive patients (age, 55.