Daytime variability of baroreflex function in patients with obstructive sleep apnoea: implications for hypertension
Daytime variability of baroreflex function in patients with obstructive sleep apnoea: implications for hypertension
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DOI：
10.1113/expphysiol.2006.035584
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发表时间：
2007-03-01
影响因子：
2.7
通讯作者：
Hainsworth, R.
中科院分区：
文献类型：
--
作者：
Cooper, V. L.;Elliott, M. W.;Hainsworth, R.
阻塞性睡眠呼吸暂停（OSA）患者睡眠期间的阻塞性事件会导致血压发生较大变化，这可能会导致压力反射功能的变化，并对长期血压控制产生影响。本研究探讨了OSA患者颈动脉压力感受器刺激反应的日间变化。我们确定了心脏和血管的反应，每3小时之间的09.00和21.00小时在20例OSA患者，使用分级吸引和压力施加到颈部衣领。将这些反应与估计的颈动脉窦压力作图，并从这些图中，分别将压力反射敏感性和工作点作为最大斜率和相应的颈动脉窦压力。我们发现，在09.00小时，控制血管阻力的敏感性最低（-1.2 +/-0.2%mmHg（-1），与12.00 h时的-1.9 +/-0.3%mmHg（-1，P < 0.02）相比），控制平均动脉压的操作点最高（101.1 ± 5.8 mmHg，12.00 h时为94.1 ± 5.8 mmHg，P < 0.05）。这与正常受试者的先前数据相反，正常受试者在09.00 h时灵敏度最高，工作点最低。我们认为，较高的压力反射敏感性和较低的工作点在早上看到正常人可能提供了一种保护机制，对高血压和这种保护是不存在的OSA患者。这是可能的反射灵敏度降低和增加工作点在早上实际上可能会促进高血压。
Obstructive events during sleep in patients with obstructive sleep apnoea (OSA) cause large alterations in blood pressure, and this may lead to changes in baroreflex function with implications for long-term blood pressure control. This study examined the daytime variations in the responses to carotid baroreceptor stimulation in OSA patients. We determined the cardiac and vascular responses every 3 h between 09.00 and 21.00 h in 20 patients with OSA, using graded suctions and pressures applied to a neck collar. These responses were plotted against estimated carotid sinus pressures and, from these plots, baroreflex sensitivities and operating points were taken as the maximal slopes and the corresponding carotid sinus pressures, respectively. We found that at 09.00 h, sensitivity for the control of vascular resistance was at its lowest (-1.2 +/- 0.2% mmHg(-1), compared with -1.9 +/- 0.3% mmHg(-1) at 12.00 h, P < 0.02) and operating point for control of mean arterial pressure was at its highest (101.1 +/- 5.8 mmHg, compared with 94.1 +/- 5.8 mmHg at 12.00 h, P < 0.05). This is in contrast to previous data from normal subjects, in whom sensitivity was highest and operating point lowest at 09.00 h. We suggest that the higher baroreflex sensitivity and lower operating point seen in the mornings in normal subjects may provide a protective mechanism against hypertension and that this protection is absent in patients with OSA. It is possible that the reduced reflex sensitivity and increased operating point in the mornings may actually promote hypertension.