Vascular markers in patients diagnosed with mild to moderate obstructive sleep apnea: a cohort study

Abstract

Background Obstructive sleep apnea (OSA) is a widespread and prevalent disorder that affects from 24 to 28% of the population. It is associated to decreased quality of life, increased road traffic accidents and increased cardiovascular (CV) risk. Currently OSA is diagnosed with an overnight polysomnography (PSG) and its 1st line treatment is a continuous positive airway pressure device (CPAP). Current guidelines only recommend CPAP treatment to reduce the CV risk of the severe patients (Apnea/Hypopnea Index≥30) and not the mild to moderate patients (Apnea/Hypopnea Index 5-29.9) even though some of these patients may have an increased CV risk. To identify these patients with an increased CV risk, we propose the use of 3 vascular markers: Ankle-Brachial Index (ABI), Carotid ultrasound and Carotid-Femoral Pulse Wave Velocity. Objectives To evaluate the utility of ABI and other vascular markers at identifying high CV risk in patients with mild to moderate minimally symptomatic OSA and no CV disease Design The study is a multicentre prospective cohort study performed in the Joan Trueta Hospital of Girona and the Sant Pau Hospital of Barcelona from 2018 to 2030. Population The study population will be mild to moderate minimally symptomatic OSA patients, diagnosed with an overnight PSG, with no CV disease diagnosed at baseline. A consecutive non-probabilistic method will be used to recruit the 1080 patients needed. These patients will be divided into 2 groups, patients with an ABI≤0.9 will be considered as “exposed” and patients with an ABI>0.9 will be considered as “not exposed”. Methods Patients included into the study will be studied to control for confounding factors and to assure they fulfil all inclusion criteria and no exclusion criteria. After this they will receive a yearly follow-up for 10 years to observe incident CV disease or death