Abstract: Objective    To explore the relationship between serum fetuin A, carotid atherosclerosis index(CSI) and carotid intima-media thickness(cIMT) in normotensive patients with obstructive sleep apnea syndrome. Methods    64 cases of OSAS patients with normal blood pressure were selected as experimental group while 30 healthy people as control. Differences of serum fetuin A, carotid atherosclerosis index  and carotid intima-media thickness between the two groups were measured and compared. Apnea hypopnea index (AHI) was determined with sleep monitor. The relationship between AHI and CSI/cIMT and correlation of fetuin-A with CSI/cIMT were analyzed. Results    The carotid atherosclerosis index and carotid intima-media thickness in experimental group were significantly higher than the control group,  but serum fetuin-A was significantly lower (P<0.05). Meanwhile, AHI of the experimental group was also significantly higher than the control (P<0.05), while the lowest oxygen saturation was significantly lower (68.42±11.65% vs. 92.55±4.64%, P<0.05). In the experimental group, Pearson correlation analysis showed AHI was positively correlated with cIMT and CSI (r=0.421, r=0.502; P<0.05) when fetuin-A was negatively correlated with cIMT and CSI (r=-0.515, r=-0.404; P<0.05). Conclusion    Reduction of serum fetuin-A is associated with subclinical carotid atherosclerosis in the patients with normotensive OSAS.

Key words: Carotid intima-media thickness, Sleep apnea hypopnea syndrome, obstructive； Fetuin A, Carotid atherosclerosis index