The Effect Of Continuous Positive Airway Pressure Treatment On Concentrations Of Endothelin And Angiotensin Ⅱ In Plasma Of Patients With Obstructive Sleep Apnea Syndrome

Objectives: (1) To evaluate the concentrations of endothelin and angiotensin â…¡ in plasma of patients with obstructive sleep apnea syndrome. (2) To discuss the effect of continuous positive airway pressure treatment on concentrations of endothelin and angiotensin â…¡ in plasma of obstructive sleep apnea syndrome patients with hypertension and the therapeutic effect on their hypertension.Methods: (1) Thirty-four patients with obstructive sleep apnea syndrome in our hospital and twenty healthy people were selected. They were carefully inquired for medical records, especially the histories of sleep apnea, including by questionnaires. The blood pressures of all subjects under quiescent condition and their blood samples were taken before getting up in the morning. The plasma samples were detected for endothelin and angiotension â…¡ with radio-immunity kit together. The sleep structures, blood pressures and the concentrations of ET and Ang â…¡ in plasma of OSAS patients and the control group were compared for differences. The MAP and the concentrations of ET and Ang â…¡ of the OSAS patients were analyzed for correlation. And the correlation between their concentrations of ET and Ang â…¡ and AHI and saturation of blood oxygen were analysed , too. (2) Twenty-six obstructivesleep apnea syndrome patients with hypertension which were suitable for continuous positive airway pressure were selected as the treatment group. They were treated with continuous positive airway pressure for three months and followed up and rechecked all mentioned above. And the concentrations of endothelin and angiotension II and blood pressures and indexes of life quality in the treatment group were compared with before.Results: ? The stage I sleep increased and NREM sleep decreased in OS AS patients. (2) The mean arterial pressures(MAP) and the concentrations of endothelin and angiotension II in plasma were higher in OSAS patients than in the control group. (3) The MAP was correlated with the concentrations of endothelin and angiotension II in OSAS patients. The coefficients of correlation were 0.416 (P< 0.05) and 0.390 (.P <0.05) , and-0.364 (P <0.05). (4) After three months' CPAP treatment, twenty patients returned. Their mean saturation of blood pressure of OSAS patients increased and AHI, MAP, and the levels of ET and Ang II reduced significantly.Conclusions: 1. The levels of Endotheline and Angiotension II in blood are higher in OSAS patients than healthy people, and they are at high risk of developing hypertension. 2. The endotheline and angiotension II play an important role in the pathogensis of hypertension in OSAS patients. 3. The endotheline and angiotension II are correlated with hypoxemia and AHI. 4. CPAP can improve the hypoxia, then reduces the levels of endothelin and angiotensin II in OSAS patients, thus it takes a therapeutical effect on the hypertension in OSAS patients.