Determination of subclinical atherosclerosis in obstructive sleep apnea syndrome patients without traditional risk factors for atherosclerosis

Objective: Obstructive sleep apnea-hypopnea syndrome (OSAS) is associated with high cardiovascular morbidity and mortality. Recent studies have suggested a pathophysiological link between OSAS and atherosclerosis; for which carotid intima-media thickness (CIMT) and pulse wave velocity (PWV) has been considered as an early marker. The aim of this study was to assess the presence of early signs of atherosclerosis and cardiovascular effects of OSAS depending on its severity, in patients without clinically diagnosed cardiovascular disease and any coincident risk factors for atherosclerosis. Material and Method: Thirty one healthy subjects without any systemic disease and OSAS, and patients with OSAS without known atherosclerosis and also without any risk factors for atherosclerosis were examined in the study. According to the severity, 30 patients were in mild OSAS, 32 were in moderate OSAS and 31 patients were in severe OSAS group. Bilateral CIMT assesment and PWV analysis were performed in patients and controls. Results: Significant differences existed between control subjects and patients with mild, moderate and severe OSAS in PWV (5.70±0.48, 6.76±0.61, 7.72±0.82, 8.94±1.72 m/sec respecitively; p<0.0001) and CIMT (0.712±0.040, 0.812±0.037, 0.900±0.056, 0.971±0.74 mm respectively; p<0.0001). AHI and TST% were positively correlated with the following; the PWV (p<0.001- r=0.67 / p<0.001- r=0,70 respectively), the maximal CIMT (p<0.001- r=0.79 / p<0.001- r=0.74 respectively), The minimal SaO₂ values were negatively correlated with the following; the PWV (p<0.001, r=-0.66), the maximal CIMT (p<0.001, r=-0.68). Conclusion: OSAS patients have tendency to atherosclerosis development, and this process increases proportionally with the severity of the disease.