Which Is the Ideal Marker for Early Atherosclerosis in Obstructive Sleep Apnea (OSA) – Carotid Intima-Media Thickness or Mean Platelet Volume?

BACKGROUND: Obstructive sleep apnea (OSA) is known to be closely associated with cardiovascular disease. Carotid intima-media thickness (IMT) is widely used for assessment of atherosclerosis. Mean platelet volume (MPV) is a new marker associated with atherothrombosis. In this study, we aimed to detect early atherosclerosis by measuring carotid intima-media thickness and to investigate the relationship between MPV and IMT and OSA severity. MATERIAL/METHODS: The study population consisted of 158 patients who underwent polysomnography and did not have any overt cardiac disease or risk factors. Carotid IMT was measured by ultrasonography. Blood samples were taken for MPV determination. Subjects were divided into 4 groups according to OSA severity: control, mild, moderate, and severe OSA. RESULTS: The patients with OSA (mild, moderate, severe) had an increased carotid IMT (0.59±0.2, 0.60±0.1, 0.64±0.1, respectively) compared to controls (0.50±0.1, p<0.05). There were no differences found between groups regarding mean platelet volume. Carotid IMT was found to be positively correlated with age, systolic blood pressure, apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and time duration with oxygen saturation <90% (T90), and negatively correlated with minimum SpO(2) and mean SpO(2). MPV was not correlated with OSA severity or other parameters. Carotid IMT was found to be effective in predicting the presence of OSA [AUC=0.769 (0.683, 0.855), p<0.001)] but MPV was not found to be effective [AUC=0.496 (0.337,0.614) p=0.946)]. CONCLUSIONS: OSA patients appear to have increased carotid IMT suggestive of an atherosclerotic process. Carotid IMT could be a more useful indicator than MPV in these patients. Long-term prospective studies are needed to confirm these results.