Hoyos Camilla M, Yee Brendon J, Wong Keith K, Grunstein Ronald R, Phillips Craig L
Sleep and Circadian Group, Centre for Integrated Research and Understanding of Sleep, Woolcock Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia; Discipline of Sleep Medicine, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia;
Sleep and Circadian Group, Centre for Integrated Research and Understanding of Sleep, Woolcock Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia; Discipline of Sleep Medicine, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia; Department of Respiratory and Sleep Medicine, Royal North Shore Hospital, Sydney, New South Wales, Australia.
Am J Hypertens. 2015 Oct;28(10):1222-8. doi: 10.1093/ajh/hpv023. Epub 2015 Mar 28.
Obstructive sleep apnea (OSA) is a risk factor for hypertension and randomized controlled trials have shown that OSA treatment with continuous positive airway pressure (CPAP) reduces peripheral blood pressure and arterial stiffness. Arterial stiffness is known to augment central aortic blood pressure independent of peripheral brachial blood pressure. Currently, it is unclear whether the reduction in blood pressure with CPAP is similar between central and peripheral sites. It is also unknown whether there are any time-of-day influences on central blood pressure changes after CPAP.
Thirty-eight patients received therapeutic and sham CPAP in random order for 8 weeks each with an intervening 1-month washout. Peripheral and central blood pressure and arterial stiffness (augmentation index and time to reflection) were measured by pulse wave analysis at end-of-treatment visits. Measurements were taken in the afternoon (2 pm) and the next morning (9 am).
Compared to sham, CPAP significantly reduced central systolic (mean difference: -4.1 mm Hg; P = 0.003), central diastolic (-3.9 mm Hg; P = 0.0009), peripheral systolic (-4.1mm Hg; P = 0.004), and peripheral diastolic (-3.8 mm Hg; P = 0.001) blood pressure. These effects were not influenced by time-of-day. Time to reflection was improved with CPAP compared to sham (3.7 ms; P = 0.01). There was no overall difference in augmentation index however when examined by time-of-day, a modest reduction with CPAP was observed in the morning (-2.5%; P = 0.03) but not in the evening (0.12%; P = 0.91).
CPAP reduces both central and peripheral blood pressure independent of the time-of-day. In contrast, modest improvements in conduit arterial stiffness after CPAP may only occur in the morning.
阻塞性睡眠呼吸暂停（OSA）是高血压的一个危险因素，随机对照试验表明，持续气道正压通气（CPAP）治疗OSA可降低外周血压和动脉僵硬度。已知动脉僵硬度会增加中心主动脉血压，而与外周肱动脉血压无关。目前尚不清楚CPAP降低血压的效果在中心和外周部位是否相似。也不清楚CPAP治疗后中心血压变化是否受一天中不同时间的影响。
38例患者随机接受治疗性CPAP和假CPAP，各治疗8周，期间有1个月的洗脱期。在治疗结束时的访视中，通过脉搏波分析测量外周和中心血压以及动脉僵硬度（增强指数和反射时间）。测量在下午（约下午2点）和次日上午（约上午9点）进行。
与假CPAP相比，CPAP显著降低了中心收缩压（平均差值：-4.1 mmHg；P = 0.003）、中心舒张压（-3.9 mmHg；P = 0.0009）、外周收缩压（-4.1 mmHg；P = 0.004）和外周舒张压（-3.8 mmHg；P = 0.001）。这些效果不受一天中不同时间的影响。与假CPAP相比，CPAP改善了反射时间（3.7 ms；P = 0.01）。增强指数总体上没有差异，然而按一天中不同时间检查时，上午CPAP有适度降低（-2.5%；P = 0.03），但晚上没有（0.12%；P = 0.91）。
CPAP可降低中心和外周血压，且与一天中不同时间无关。相比之下，CPAP治疗后传导动脉僵硬度的适度改善可能仅发生在上午。
