Hoffstein V, Mateika J
Department of Medicine, St. Michael's Hospital, University of Toronto, Ontario, Canada.
Chest. 1992 Feb;101(2):379-84. doi: 10.1378/chest.101.2.379.
This study was designed to test a hypothesis that patients with sleep apnea have higher blood pressure in the morning, following a night spent in apnea and hypoxemia, than in the evening. To accomplish this, we prospectively studied a set of 611 patients referred to our clinic because of suspicion of sleep apnea. All patients had full nocturnal polysomnography, including measurement of snoring. Blood pressure was measured in the evening, prior to onset of sleep, and in the morning, immediately on awakening. We found that patients without apnea and hypoxemia had lower blood pressure in the morning compared with the evening value, while patients with severe sleep apnea and hypoxemia had higher blood pressure in the morning; these evening-to-morning blood pressure differences, although statistically significant, were small, typically 1 to 4 mm Hg. Morning blood pressures were higher in patients with sleep apnea and hypoxemia than in nonapneic normoxic patients. However, this difference disappeared after the groups were matched for age and body mass index. We conclude that (1) patients with sleep apnea and nocturnal hypoxemia lose the expected morning dip in arterial blood pressure, and (2) age and body mass index are more important correlates of blood pressure than apnea and nocturnal oxygen desaturation. We speculate that the loss of evening-to-morning drop in blood pressure, if present over a long period of time, may lead to sustained elevations in arterial blood pressure frequently observed in patients with sleep apnea.
睡眠呼吸暂停患者在经历一夜的呼吸暂停和低氧血症后，早晨的血压高于晚上。为实现这一目标，我们前瞻性地研究了一组因疑似睡眠呼吸暂停而转诊至我们诊所的611例患者。所有患者均进行了全夜多导睡眠监测，包括打鼾测量。在晚上睡眠开始前和早晨醒来后立即测量血压。我们发现，无呼吸暂停和低氧血症的患者早晨血压低于晚上的值，而患有严重睡眠呼吸暂停和低氧血症的患者早晨血压较高；这些早晚血压差异虽有统计学意义，但很小，通常为1至4毫米汞柱。睡眠呼吸暂停和低氧血症患者的早晨血压高于无呼吸暂停的正常氧合患者。然而，在根据年龄和体重指数对两组进行匹配后，这种差异消失了。我们得出结论：（1）睡眠呼吸暂停和夜间低氧血症患者失去了预期的早晨动脉血压下降；（2）年龄和体重指数比呼吸暂停和夜间氧饱和度下降更重要的血压相关因素。我们推测，如果长时间存在早晚血压下降的缺失，可能会导致睡眠呼吸暂停患者经常观察到的动脉血压持续升高。
