Ziegler M G, Nelesen R A, Mills P J, Ancoli-Israel S, Clausen J L, Watkins L, Dimsdale J E
Department of Medicine, University of California at San Diego 92103-8341, USA.
Sleep. 1995 Dec;18(10):859-65.
Many persons with sleep apnea are hypertensive. Forty-two subjects of similar age and weight were divided into four groups of hypertensives and normotensives with and without sleep apnea. All subjects had heart rate, blood pressure (BP), baroreflex sensitivity and pressor sensitivity to phenylephrine measured while breathing room air or 15% oxygen. Hypoxia raised heart rate and lowered BP in all groups (p < 0.001), with the greatest hypotensive effect among hypertensives. Hypertensives had blunted baroreflex sensitivity, and breathing a hypoxic mixture lowered baroreflex sensitivity of all four groups (p = 0.008). The apneic subjects tended to lower their baroreflex sensitivity more in response to hypoxia and also had an enhanced pressor response to phenylephrine, whether breathing room air or 15% oxygen. Episodes of sleep apnea lead to hypoxia, an initial period of hypotension and a subsequent increase in sympathetic nervous activity. Our studies suggest that apneics could have an exaggerated pressor sensitivity to norepinephrine. They might also have difficulty returning BP to normal levels, because hypoxia impaired baroreflexes.
许多患有睡眠呼吸暂停的人都患有高血压。42名年龄和体重相近的受试者被分为四组，分别是有睡眠呼吸暂停的高血压患者、无睡眠呼吸暂停的高血压患者、有睡眠呼吸暂停的血压正常者和无睡眠呼吸暂停的血压正常者。在呼吸室内空气或15%氧气时，对所有受试者的心率、血压（BP）、压力反射敏感性和对去氧肾上腺素的升压敏感性进行了测量。低氧使所有组的心率升高，血压降低（p<0.001），其中高血压患者的降压效果最为显著。高血压患者的压力反射敏感性减弱，呼吸低氧混合气降低了所有四组的压力反射敏感性（p = 0.008）。无论呼吸室内空气还是15%氧气，呼吸暂停受试者对低氧的反应往往会使其压力反射敏感性降低得更多，并且对去氧肾上腺素的升压反应增强。睡眠呼吸暂停发作会导致低氧、最初的低血压期以及随后交感神经活动增加。我们的研究表明，呼吸暂停患者对去甲肾上腺素可能具有过度的升压敏感性。他们可能也难以使血压恢复到正常水平，因为低氧会损害压力反射。
