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 (e^β (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.