Objective: To explore the role of endothelin-1 (ET-1) in the pathogenesis of hypertension in obstructive sleep apnea hypopnea syndrome (OSAHS).
Methods: The levels of serum ET-1 in 30 OSAHS patients accompanied by hypertension, 30 normotensive OSAHS patients and 30 healthy controls were measured by ET-1 enzyme immunoassay kit. Meanwhile the correlation about the concentration of ET-1 in OSAHS patients with the clinic, polysomnography (PSG) parameters was analyzed.
Results: OSAHS patients with or without hypertension compared with snoring group and normal people, the sleep structure was significantly disturbed. The time percentages of awake and stage I sleep were increased, while stage II sleep decreased significantly in OSAHS patients than those in snoring group (P < 0.01, respectively). There were no significantly difference about the sleep structure in the two OSAHS groups. The levels of serum ET-1 (mean +/- s) were significantly higher in OSAHS patients accompanied by hypertension and normotensive OSAHS patients(42.5 +/- 8.4) ng/L and (38.6 +/- 4.7) ng/L respectively than those in the healthy controls(33.1 +/- 5.4) ng/L (P < 0.01, respectively). In the two OSAHS groups, the levels of serum ET-1 were significantly higher in OSAHS patients accompanied by hypertension than those in the normotensive OSAHS patients (P < 0.05). There were positive correlations between the concentration of ET-1 and the apnea hypopnea index (AHI) in all the 60 OSAHS patients with and without hypertension (r = 0.334, P < 0.01). There were negative correlations between the concentration of ET-1 and the lowest oxygen desaturation in all the 60 OSAHS patients with and without hypertension (r = -0.230, P < 0.05).
Conclusion: These results indicate that the sleep disordered breathing and hypoxia may contribute to the elevation of ET-1 in the OSAHS patients and OSAHS patients accompanied by hypertension. ET-1 may play an important role in the pathogenesis of OSAHS-induced hypertension.