Abstract

"Introduction: Obstructive sleep apnea syndrome (OSA) is the result of repetitive collapse of the upper airway during the sleep. There is a group of patients with a positional component; which is defined as a reduction of at least 50% in the apnea hypopnea index (AHI) from the supine to a lateral position. Objective: The purpose of this study is to determine positional OSA prevalence and compare clinical characteristics and polygraph recordings among this group of patients. Methods: Prospective study of polygraph recording of patients with suspect of OSA between 2009-2014. Demographic, anthropometric, comorbidities and polygraph recording data was collected. OSA was defined as AHI > 5 events per hour Results: From a total of 457 patients with OSA diagnose, 243 had a positional component (53%). Positional Sleep Apnea patients had mild AHI (p < 0.001), a lower neck circumference (p = 0.001), lower Body Mass Index (p = 0.003) and a lower presence of arterial hypertension (p = 0.001). The multivariable analysis confirmed that there is a lower probability in Positional OSA in patients with Severe AHI (OR 0,96: IC 0,94-0,97), with hypertension (0,54: IC 0,33-0,88) and males (OR 0,41: IC 0,21-0,81). Conclusions: Positional obstructive sleep apnea is a very frequent condition presented in 53% of OSA patients; these patients have often mild AHI, lower BMI, lower neck circumference, less hypertensive, and are usually females."