Association between Respiratory Sleep Indices and Cardiovascular Disease in Sleep Apnea-A Community-Based Study in Cyprus

Frangiskos Frangopoulos; Ivi Nicolaou; Savvas Zannetos; Nicholas-Tiberio Economou; Tonia Adamide; Georgia Trakada

doi:10.3390/jcm9082475

Association between Respiratory Sleep Indices and Cardiovascular Disease in Sleep Apnea-A Community-Based Study in Cyprus

J Clin Med. 2020 Aug 1;9(8):2475. doi: 10.3390/jcm9082475.

Authors

Frangiskos Frangopoulos¹, Ivi Nicolaou¹, Savvas Zannetos², Nicholas-Tiberio Economou³, Tonia Adamide¹, Georgia Trakada³

Affiliations

¹ Respiratory Department, Nicosia General Hospital, 215 Nicosia-Limassol Old Road, Strovolos 2029, Nicosia, Cyprus.
² Department of Healthcare Management, Neapolis University, Pafos 8042, Cyprus.
³ Division of Pulmonology, Department of Clinical Therapeutics, School of Medicine, National and Kapodistrian University of Athens, Alexandra Hospital, 11528 Athens, Greece.

Abstract

Obstructive sleep apnea (OSA) is a chronic and prevalent disorder, strongly associated with cardiovascular disease (CVD). The apnea-hypopnea index (AHI), or respiratory event index (REI), and the oxygen desaturation index (ODI) are the clinical metrics of sleep apnea in terms of diagnosis and severity. However, AHI, or REI, does not quantify OSA-related hypoxemia and poorly predicts the consequences of sleep apnea in cardiometabolic diseases. Moreover, it is unclear whether ODI correlates with CVD in OSA. Our study aimed to examine the possible associations between respiratory sleep indices and CVD in OSA, in a non-clinic-based population in Cyprus. We screened 344 subjects of a stratified, total sample of 4118 eligible responders. All participants were adults (age 18+), residing in Cyprus. Each patient answered with a detailed clinical history in terms of CVD. A type III sleep test was performed on 282 subjects (81.97%). OSA (REI ≥ 15) was diagnosed in 92 patients (32.62%, Group A). REI < 15 was observed in the remaining 190 subjects (67.37%, Group B). In OSA group A, 40 individuals (43%) reported hypertension, 17 (18.5%) arrhythmias, 10 (11%) heart failure, 9 (9.8%) ischemic heart disease and 2 (2%) previous stroke, versus 46 (24%), 21 (11%), 7 (3.7%), 12 (6.3%) and 6 (3%), in Group B, respectively. Hypertension correlated with REI (p = 0.001), ODI (p = 0.003) and mean SaO₂ (p < 0.001). Arrhythmias correlated with mean SaO₂ (p = 0.001) and time spent under 90% oxygen saturation (p = 0.040). Heart failure correlated with REI (p = 0.043), especially in the supine position (0.036). No statistically significant correlations were observed between ischemic heart disease or stroke and REI, ODI and mean SaO₂. The pathogenesis underlying CVD in OSA is variable. According to our data, hypertension correlated with REI, ODI and mean SaO₂. Arrhythmias correlated only with hypoxemia (mean SaO₂), whereas heart failure correlated only with REI, especially in the supine position.

Keywords: arrhythmias; heart failure; hypertension; ischemic heart disease; obstructive sleep apnea (OSA); oxygen desaturation index (ODI); respiratory event index (REI); stroke.