Evaluation of Obstructive Sleep Apnea and Endothelial Function in Resistant Hypertension Patients

Obstructive sleep apnea (OSA) is considered an independent risk factor for cardiovascular disease. There is evidence that individuals with OSA may have increased inflammatory mediators, changes in the metabolic profile, increased sympathetic activity with consequent elevation of blood pressure (BP) and endothelial dysfunction. Resistant hypertension (RH) is defined as uncontrolled blood pressure (BP ≥ 140/90mmHg) despite the current use of three hypotensive drugs at full doses, including a diuretic, or the need for >3 medications to control BP. OSA has been reported as the most common secondary cause of high blood pressure maintenance.

To determine the prevalence of OSA and associate it with the endothelial function behavior in patients with resistant hypertension comparing to those with BP controlled by medication.

Methods: A cross-sectional study involving 40 hypertensive patients (20 with resistant hypertension and 20 with controlled BP), irrespective of race or gender, with ages between 18 and 75 years. BP was measured by oscillometric method on automatic device. Endothelial function was assessed by peripheral arterial tonometry (PAT) by EndoPAT2000® and the OSA diagnosis also through PAT, using the portable device WatchPAT200®. Anthropometric evaluation was performed through measurements of waist, hip and neck circumference, body mass index, waist to height ratio (WHtR), and body composition assessed by bioelectrical impedance. Statistical analyzes were performed by GraphPad Prism software.