[Association of obstructive sleep apnea hypopnea syndrome with carotid atherosclerosis and the efficacy of continuous positive airway pressure treatment].

OBJECTIVE: To evaluate the association of obstructive sleep apnea hypopnea syndrome (OSAHS) with carotid atherosclerosis and the efficacy of continuous positive airway pressure (CPAP) treatment.

METHODS: A total of 93 OSAHS patients diagnosed by polysomnography (PSG) were selected from Sleep Disorders Center at Affiliated Hospital of Xuzhou Medical College between March 2013 and December 2014. Based on the results of apnea-hypopnea index (AHI), they were divided into mild (n=22), moderate (n=37), and severe OSAHS group (n=34). Meanwhile, 28 healthy adult individuals matched for age and body mass index (BMI) were enrolled as the control group. The carotid intima-mesa thickness (IMT) was measured by color Doppler uhrasonography, and plasma levels of tumor necrosis factor-α (TNF-α), endothelin-1 (ET-1) and nitric oxide (NO) were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The correlations between carotid IMT and plasma levels of TNF-α, ET-1 and NO were analyzed. A total of 24 patients with moderate to severe OSAHS underwent CPAP treatment and the carotid IMT, plasma levels of TNF-α, ET-1 and NO were compared before and after CPAP treatment.

RESULTS: OSAHS patients had significant increase of carotid IMT with the increasing disease severity, and the carotid IMT in mild, moderate and severe OSAHS groups were all significantly higher than that in the control group ((0.73 ± 0.31), (0.86 ± 0.07), (1.07 ± 0.14) vs (0.65 ± 0.10) mm, all P<0.05). The plasma levels of TNF-α and ET-1 in mild to severe OSAHS group were significantly higher than those in controls ((17.45 ± 3.02), (23.81 ± 2.91), (35.16 ± 3.43) vs (12.53 ± 3.48) ng/L and (0.81 ± 0.13), (1.06 ± 0.21), (1.66 ± 0.30) vs (0.64 ± 0.12) ng/L, all P<0.05 ), whereas plasma levels of NO in the three OSAHS groups were significantly decreased compared with the control group ((35.46 ± 10.12), (29.32 ± 9.47), (20.16 ± 7.41) vs (45.43 ± 7.92) µmol/L, all P<0.05). Furthermore, there were significant differences in plasma levels of TNF-α, ET-1 and NO among the three OSAHS groups (all P<0.05). Carotid IMT was positively correlated with plasma TNF-α and ET-1 (r=0.56 and 0.51) and negatively correlated with plasma NO (r=-0.46) (all P<0.05). After 3 months of CPAP treatment, plasma levels of TNF-α and ET-1 in OSAHS patients were significantly reduced ((19.64 ± 5.28), (0.94 ± 0.21) vs (28.72 ± 5.36), (1.36 ± 0.36) ng/L), and plasma NO was markedly increased ((33.57 ± 6.32) vs (24.34 ± 4.46) µmol/L, all P<0.05). However, CPAP treatment did not have a significant effect on carotid IMT ((0.91 ± 0.21) vs (0.96 ± 0.14) mm), P>0.05).

CONCLUSIONS: Systemic inflammation and vascular endothelial dysfunction may play an important role in pathogenesis and development of carotid artery atherosclerosis in OSAHS. Short-term CPAP therapy alleviates systemic inflammation and improves endothelial function, but does not influence the increased carotid IMT in OSAHS patients.