Prevalence of Obstructive Sleep Apnoea and Its Association With Atherosclerotic Plaques in a Cohort of Subjects With Mild–Moderate Cardiovascular Risk

Introduction: Classic cardiovascular risk factors do not explain all the cardiovascular events. Obstructive sleep apnoea (OSA) has been proposed as a potential and prevalent cardiovascular risk factor. Our study aimed to describe the prevalence of OSA in a middle-aged cohort with mild–moderate cardiovascular risk and evaluate its association with atherosclerotic disease. Methods: This is an observational cross-sectional ancillary study of the ILERVAS project which was aimed to study subclinical arterial disease in a cohort with mild–moderate cardiovascular risk. In a sample of consecutive subjects, we performed a sleep study and evaluate OSA prevalence and its association with carotid and femoral atheroma plaques and atherosclerotic burden. Results: Overall, 966 subjects with a median age of 57 years (25–75th percentile; 52–62) and a body mass index (BMI) of 28.5kg/m2 (25.6–31.6) were included. Of these, 72.6% (69.7%–75.3%) had OSA (apnoea–hypopnoea index (AHI)≥5/h); 35.7% (32.8%–38.8%) had mild OSA (AHI 5–14.9/h) and 36.9% (33.9%–39.9%) had moderate/severe OSA (AHI≥15/h). Mean oxygen saturation and the percentage of time with oxygen saturation<90% (CT90) were associated with atherosclerotic burden (eβ (95%CI) 0.932 (0.892, 0.974); 1.005 (1.002, 1.009), respectively) and total plaque (OR (95%CI) 0.88 (0.797,0.971); 1.013 (1.004,1.021), respectively). No association with the AHI or oxygen desaturation index was found. Conclusions: This study confirms a high prevalence of OSA in patients with mild–moderate cardiovascular risk and shows an association between atherosclerotic burden, total and femoral plaque with CT90 and mean oxygen saturation, suggesting the importance of OSA-related hypoxaemia in the induction of atherosclerotic disease. (AU)