Research On Blood ET And CGRP In Patients With OSAHS Complicated By Hypertension

bjective: To investingate the relation between hypoxemia in patients with OSAHSand hypertension. To evaluate the changes of plasma calcitonin gene related peptideand plasma endothelin-1 in patients with OSAHS and explore' the correlation betweenOSAHS and hypertension.Methods: Polysomnography(PSG) was performed in 104 patients with OSAHS andin 30 healthy controls(groupⅢ). the relation between various sleep disorderedbreathing events and blood pressure in patients with OSAHS was analyzed. Accordingto the presence of hypertension or not, OSAHS patients were divided into twogroups, OSAHS with hypertension group(57patients, groupⅠ)and OSAHSwithout hypertension group(47 patients, groupⅡ).The PSG results were comparedamong three groups. After excluded the patients who were taking medicine andcomplicated with the serious infect and the heart and lung disease, we selected 22OSAHS patients with hypertension diagnosed for the first time(group A) from groupⅠ.Matched age, gender and body mass index(BMI) Matched, 20 OSAHS patientswithout hypertension were randomly selected from groupⅡas simple OSAHSgroup(group B).23 healthy controls were randomly selected as group C. Bloodsamples from 65 patients were taken in the morning, plasma ET-1 and CGRP, weremeasured by radioimmunoassay.Results:1. the relation between hypoxemia in patients with OSAHS and hypertension.l)OSAHS patients with hypertension showed more frequently apnea-hypopneaindex(AHI 50.31±25.54 vs38.95±24.54 P＜0.05).But, compared with OSAHSwithout hypertension group,. hypoxia index increased(48.59±25.66vs36.98±22.31 P＜0.01). 2) Changes in systolic blood pressure and diastolic bloodpressure level in OSAHS patients(groupⅠ+Ⅱ)were correlated statistically withchanges in BMI, apnea-hypopnea index (AHI), hypoxia index respectively. Furthermore, stepwise regression analysis showed that hypoxia index was mostcontributed to change of diastolic blood pressure in patients with OSAHS(R~2:0.216P=0.000).2. Study of blood level of ET 1 and CGRP in patients with OSAHS1) Matched age, gender and BMI, plasma ET-1 level in group C, group B and group Aincreased progressively, plasma CORP level did not change significantly andCGRP/ET-1 decreased progressively(15.23±3.66 pg/ml vs 11.75±4.11 pg/ml, P＜0.01;15.23±3.66 pg/ml vs 7.02±2.81 pg/ml P＜0.01 CGRP/ET-1 2.45±1.69 vs 7.29±3.02P＜0.01;).2) Changes in plasma ET-1 level in OSAHS patients(group A+B) were correlatedstatistically with changes in AHI, hypoxia index and OLT90％(r=0.621,P=0.000; r=0.655, P=0.000; r=0.411, P=0.030), respectively. Furthermore,stepwise regression nalysis showed that hypoxia index was most contributedto change of plasma ET-1 level in patients with OSAHS( R~2:0.407 P=0.000)。3) Changes in plasma ET-1 level in patients with OSAHS were positively correlatedwith changes in diastolic blood pressure, but not with changes in systolic bloodpressure(r=0.546, P=0.003)。.Conclusions1) The degree of AHI were correlated statistically with changes in systolic bloodpressure, diastolic blood pressure in OSAHS patients. 2) There was vascularendothelial dysfunction, which featured by the elevated ET-1 level, in patients withOSAHS.3) Repetitive episodic hypoxia, which is among the pathogenesis caused bysleep apnea, may play the important role in the elevated ET-1 level in patients withOSAHS. And plasma ET-1 level in patients with OSAHS were poitively correlatedwith diastolic blood pressure.