Effect of obstructive sleep apnea on carotid artery intima media thickness related to inflammation

Obstructive sleep apnea hypopnea syndrome (OSAHS) is an independent risk factor for atherosclerosis. To ascertain the effect of OSAHS on the development of atherosclerosis in Chinese OSAHS patients, we evaluated markers of atherosclerosis as well as vascular endothelial function and inflammation.

Chinese men with polysomnography-diagnosed OSAHS were subgrouped into mild-moderate (n = 28) and severe (n = 54) OSAHS groups on the basis of apnea hypopnea index (AHI) scores. The control group was made up of 30 healthy men. Atherosclerosis was assessed by carotid artery intima-media thickness (IMT) of both sides, flow-mediated dilation (FMD), and inflammation by interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) levels.

Linear regression analysis was used to identify significant associations among risk factors and carotid IMT. The following parameters were significantly higher in patients with severe OSAHS than in the control group: waking triglycerides, total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, blood uric acid, blood glucose, IL-6 and hs-CRP. FMD in severe OSAHS patients was lower than in the control group. AHI score, waking hs-CRP, waking oxidized low-density lipoprotein, blood glucose, and vascular endothelial growth factor (VEGF) level were positively associated with IMT.

In Chinese male patients with severe OSAHS, the significantly higher carotid IMT and levels of inflammatory factors (IL-6 and hs-CRP) and lower FMD suggest that arterial endothelial damage and inflammation may play important roles in the development of atherosclerosis in OSAHS patients.