Impact of inflammation and oxidative stress on carotid intima-media thickness in obstructive sleep apnea patients without metabolic syndrome

Obstructive sleep apnea (OSA) increases the risk of cardiovascular diseases, and carotid intima-media thickness (IMT) is a good indicator of the severity of atherosclerotic disease. This study tested the hypothesis that inflammation and oxidative stress determined carotid IMT in patients with OSA. The carotid IMT, mean systolic and diastolic pressure (night and morning) were significantly higher and the level of thiols and high-density lipoprotein were significantly lower in our 121 OSA patients than in 27 controls (P < 0.05). The apnea/hypopnea index was correlated positively with E-selectin (r = 0.222, P = 0.014), total cholesterol (r = 0.185, P = 0.042), low-density lipoprotein (r = 0.264, P = 0.003) and HbA1c levels (r = 0.304, P = 0.001), but inversely with high-density lipoprotein level (r = −0.203, P = 0.025) in the 121 patients with OSA. In OSA subjects, multiple linear regression analysis revealed that age, systolic blood pressure and intercellular cell adhesion molecule-1 level associated independently with carotid IMT. Besides both age and systolic blood pressure, our study demonstrated that intercellular cell adhesion molecule-1 level was associated significantly with carotid IMT in those patients who had OSA but without metabolic syndrome.