Imadojemu Virginia A, Gleeson Kevin, Quraishi Sadeq A, Kunselman Allen R, Sinoway Lawrence I, Leuenberger Urs A
Division of Pulmonary, Allergy and Critical Care, and Department of Health Evaluation Sciences, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA.
Am J Respir Crit Care Med. 2002 Apr 1;165(7):950-3. doi: 10.1164/ajrccm.165.7.2102003.
Obstructive sleep apnea causes cardiovascular morbidity and premature death. Potential links between sleep apnea and cardiovascular complications are chronically elevated activity of the sympathetic nervous system and abnormal vascular function. To explore vascular function, we determined the reactive hyperemic blood flow (RHBF) responses to 10 minutes of forearm arterial occlusion (plethysmography), blood pressure, and muscle sympathetic nerve activity (MSNA, microneurography) in eight patients with sleep apnea and in nine nonapneic control subjects. Peak RHBF and vascular conductance were markedly attenuated in sleep apnea compared with control subjects (p < 0.05). Seven sleep apnea patients were retested after at least two weeks of continuous positive airway pressure (CPAP) therapy. MSNA decreased after CPAP therapy (p < 0.05, n = 6), whereas blood pressure did not change. After CPAP therapy, peak RHBF and vascular conductance were increased compared with before treatment (p < 0.05; n = 7). Thus, vascular function is abnormal in sleep apnea and is improved by CPAP therapy. Furthermore, effective CPAP therapy decreases sympathetic activity in sleep apnea. Thus, sympathoexcitation and abnormal vascular function in patients with sleep apnea appear to be linked to the repetitive nocturnal apneic events.
阻塞性睡眠呼吸暂停会导致心血管疾病和过早死亡。睡眠呼吸暂停与心血管并发症之间的潜在联系是交感神经系统的长期活动增强和血管功能异常。为了探究血管功能，我们测定了8名睡眠呼吸暂停患者和9名无呼吸对照组受试者对10分钟前臂动脉闭塞（体积描记法）的反应性充血血流（RHBF）、血压以及肌肉交感神经活动（MSNA，微神经ography）。与对照组相比，睡眠呼吸暂停患者的RHBF峰值和血管传导明显减弱（p < 0.05）。7名睡眠呼吸暂停患者在接受至少两周的持续气道正压通气（CPAP）治疗后进行了重新测试。CPAP治疗后MSNA降低（p < 0.05，n = 6），而血压未改变。CPAP治疗后，与治疗前相比，RHBF峰值和血管传导增加（p < 0.05；n = 7）。因此，睡眠呼吸暂停患者的血管功能异常，CPAP治疗可改善这种异常。此外，有效的CPAP治疗可降低睡眠呼吸暂停患者的交感神经活动。因此，睡眠呼吸暂停患者的交感神经兴奋和异常血管功能似乎与夜间反复出现的呼吸暂停事件有关。
