[Effect of movement arousal and hypoxia on circardian blood pressure in hypertensive patients with obstructive sleep apnea syndrome].
OBJECTIVE
To investigate whether repeated arousals and hypoxia at the end of apnea contribute to nocturnal and diurnal elevation of blood pressure in obstructive sleep apnea syndrome (OSAS) patients with hypertension.


METHODS
30 OSAS patients with hypertension and 30 OSAS patients without hypertension were studied. Movement arousal index (MAI), cortical arousal index (CAI), length of time during which nocturnal oxygen saturation decreased below 90% (OLT90%), apnea/hypopnea index (AHI), 24 h average systolic and diastolic blood pressure (ASBP and ADBP) were measured. Multiple stepwise regression analysis was performed to find the correlation between 24 h ASBP, ADBP and MAI, CAI, OLT90%, AHI, age, body mass index in OSAS patients with hypertension.


RESULTS
MAI made the most significant contribution to 24 h ASBP and ADBP in OSAS patients with hypertension (ASBP: r = 0.485, P < 0.01; ADBP: r = 0.407, P < 0.05). OLT90% was the second most important contributing factor (ASBP: r = 0.382, P < 0.05; ADBP: r = 0.369, P < 0.05).


CONCLUSIONS
Movement arousal and hypoxia may make an important contribution to circardian elevation of blood pressure in OSAS patients with hypertension. Both of them may contribute to the development of nocturnal and diurnal hypertension in patients with OSAS.
Zhang
Li-qiang
LQ
Department of Respiratory Diseases, The Third Hospital, Beijing University, Beijing 100083, China.
Yao
Wan-zhen
WZ
He
Quan-ying
QY
Wang
Yu-zhu
YZ
Ren
Bin
B
D000328:Adult; D001143:Arousal / Q000502:physiology*; D001794:Blood Pressure; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*