Objective To investigate the correlation between PSG parameters and high blood pressure in night and day for obstructive sleep apnea-hypopnea syndrome (OSAHS) patients. Method 223 cases were divided into three groups: the simple OSAHS group of 96 cases, the OSAHS with hypertension of 66 cases and the normal control group of 61 cases. All subjects were subjected to ABPM monitoring for two periods, from 7:00 to 21:00 and from 21:00 to 7:00 the next day. While these subjects were subjected to PSG monitoring from 21:00 to 7:00 on the next day . Regression analysis was separately performed to find the correlation between blood pressure (ABPM) parameters and PSG parameters in OSAHS patients with hypertension. Result PSG parameters of AHI, night-awakening index, below 90 percent by oxygen and oxygen saturation index were different between the simple OSAHS group, the OSAHShypertension group and the normal control group (P＜0.01). The multiple regression analysis on the correlation of DABPS and PSG parameters for OSAHS patients with hypertension showed that only nightawakening number (times/H) was introduced into the regression equation（partial regression coefficient=0.55249, P=0.0001）; of DABPS, only the aerobic index was introduced into the regression equation（partial regression coefficient=0.34201, P=0.0293）; of NABPS, microawakening index, apnea+low ventilation and oxygen by the time were introduced into the regression equation（partial regression coefficient=0.34216, P=0.0287; partial regression coefficient=0.46876, P=0.0308; partial regression coefficien=0.40204, P=0.0249）; of DABPS, apnea hypopnea+total time, 90 percent oxygen by saturation index (time/h) and oxygen index were introduced into the regression equation(partial regression coefficien=0.39443, P=0.0390;partial regression coefficient=0.39142, P=0.0399; partial regression coefficient=0.40360, P=0.0246). Conclusions The blood pressure of OSAHS patients lost normal rhythm variation, representing that the blood pressure increases in day and night.For all OSAHS patients, the higher the AHI, night-awakening index, 90 percent low saturation index and oxygen desaturation index, the more probably the patient sufferes from hypertension.For OSAHS patients with hypertension, daytime shrink pressure positively correlated with night-awakening index; daytime diastolic pressure is positively correlated with oxygen desaturation index; night shrink pressure is positively correlated with night-awakening index, apnea+hypopnea total time and oxygen desaturation index; the night diastolic pressure is positively correlated with apnea+hypopnea total time, 90 percent low saturation index and oxygen desaturation index.
