Changes in Plasma Angiotensin II and Circadian Rhythm of Blood Pressure in Hypertensive Patients with Sleep Apnea Syndrome Before and After Treatment

Objective To explore the changes in plasma angiotensin II （Ang Ⅱ） and circadian rhythm of blood pressure among hypertensive patients with sleep apnea syndrome （SAS） before and after continuous positive airway pressure （CPAP） or surgical treatment. Methods A total of 180 essential hypertension patients were enrolled in our study. The determination of plasma Ang Ⅱ concentration, ambulatory blood pressure （ABP）, and polysomnography （PSG） monitoring were performed before and 3 months after CPAP or surgical treatment. Results Patients were classified into three groups by their apnea-hypopnea index （AHI）： essential hypertension group （EH group, n=72; AHI〈5）, essential hypertension with mild SAS group （EH＋mild SAS group, n=60, 5≤AHI〈20）, and essential hypertension with moderate and severe SAS group （EH＋moderate-severe SAS group, n=48, AHI_〉20）. The concentrations of plasma AngⅡ in the above three groups were 13.42±3.27, 16.17±3.82, and 18.73±4.05 ng/mL respectively before treatment, and AngⅡ concentration in EH patients combined with SAS was significantly higher than that in EH group （all P〈0.05）. After treatment the values in the latter two groups significantly decreased to 14.67±2.56 and 15.03±3.41 ng/mL respectively （P〈0.05）. The incidence of non-dipper blood pressure curve in EH patients was 31.9%, and those in hypertensive patients with mild SAS and moderate-severe SAS were 51.7% and 58.3%, respectively before treatment. The incidence of non-dipper blood pressure curve in the EH patients with mild SAS was significantly higher than that of patients with EH alone （P〈0.05）. After CPAP treatment or surgery, the incidence of non-dipper blood pressure curve in the two SAS groups was significantly decreased to 38.3% and 39.6%, respectively （P〈0.05）. Conclusions Ang Ⅱ might play a role in blood pressure variability in patients with obstructive SAS. CPAP or surgical treatment can improve blood pressure disorder and decrease plasma Ang Ⅱ level in patients with obstructive SAS.

Effect of Chinese Herbal Medicine for Calming Gan(肝) and Suppressing Hyperactive Yang on Arterial Elasticity Function and Circadian Rhythm of Blood Pressure in Patients with Essential Hypertension

Objective：To observe the effect of Chinese herbal medicine for calming Gan（肝） and suppressing hyperactive yang（平肝潜阳,CGSHY） on arterial elasticity function and the circadian rhythm of blood pressure in patients with essential hypertension（EH）.Methods：Adopting a parallel,randomized design,sixty-four patients with EH of stagesⅠandⅡwere randomly divided into two groups according to a random number table,with 32 in each group.The patients in the treatment group were treated with CGSHY and those in the control group were treated with Enalapril.All patients were given 24-h ambulatory blood pressure monitoring（ABPM） before and after a 12-week treatment.Trough/peak（T/P） ratios of systolic and diastolic blood pressure（SBP DBP） of each group were calculated.The circadian rhythm of their blood pressure was observed at the same time. The changes in elasticity of the carotid artery in the patients,including stiffness parameter（β）,pressure-strain elastic modulus（Ep）,arterial compliance（AC）,augmentation index（Al）,and pulse wave velocity（PVWβ） were determined by the echo-tracking technique before and after a 12-week treatment.In the meantime,their levels of nitric oxide（NO） and endothelin-1（ET-1） were measured respectively.Results：After treatment,all parameters in the 24-h ABPM and the elasticity of the carotid artery（β,Ep,AC and PVWβ） were markedly improved,the level of NO was increased,and ET-1 was decreased in both groups as compared with values before treatment （P0.05 or P0.01）.Further,the improvements in the ratio of T/P of SBP DBP and in the level of NO and ET-1 in the treatment group were more significant than those in the control group（P0.05）.There were no significant differences in all parameters in the ABPM monitoring and the elasticity of the carotid artery,the recovery of blood pressure circadian rhythm,and the therapeutic effect of antihypertension in EH patients between the two groups （P0.05）.Conclusions：Chinese herbal medicine for CGSHY may lower the blood pressure smoothly and recover the circadian rhythm of blood pressure in EH patients.They may also improve the carotid elasticity of EH patients similar to that of Enalapril.The mechanism of action of Chinese herbs on EH might be related to the regulation of vascular endothelium function.