Faulx Michael D, Larkin Emma K, Hoit Brian D, Aylor Joan E, Wright Andrew T, Redline Susan
Division of Cardiology, Case Western Reserve University, University Hospitals of Cleveland, OH, USA.
Sleep. 2004 Sep 15;27(6):1113-20. doi: 10.1093/sleep/27.6.1113.
The bases for the association between sleep-disordered breathing (SDB) and cardiovascular disease are poorly understood. Endothelial dysfunction, assessed with brachial artery ultrasonography, may predict cardiovascular risk and represent preclinical vascular disease. We determined whether flow-mediated dilation (FMD) and peak blood flow (PBF) increase after cuff occlusion is altered with SDB.
193 participants (58% women) in a cohort study were studied with overnight polysomnography and subsequent brachial artery ultrasonography. SDB was quantified using the apnea-hypopnea index (AHI) and indexes of overnight desaturation and arousal frequency. Two-dimensional and Doppler-velocity measurements of the brachial artery were obtained at baseline and after 5 minutes of upper-arm cuff occlusion. FMD and PBF were defined as the percentage changes from baseline in brachial artery diameter and flow, respectively.
In the entire sample, the AHI was inversely associated with both FMD (r = -0.30, P < .001) and PBF (r = -0.20, P < .001). However, sex-stratified univariate analyses showed that these relationships were exclusive to women. Specifically, FMD was significantly lower in women with an AHI > or = 15 than in women with lower AHI scores (P < .005), with no relationship between AHI and FMD in men. Additionally, PBF decreased significantly with increasing AHI (r = -0.29, P = .010) in women alone. Statistical modeling, adjusting for body mass index, age, and other covariates, similarly showed that SDB severity significantly influenced FMD and PBF, with significant interactions between sex and AHI, reinforcing that the associations between SDB severity and endothelial function were stronger in women than in men.
Moderate levels of SBD are associated with impaired conduit and resistance endothelial function in women. Women with SDB may be more vulnerable to early SDB-related cardiovascular disease than are men.
睡眠呼吸紊乱（SDB）与心血管疾病之间关联的基础尚不清楚。通过肱动脉超声检查评估的内皮功能障碍可能预测心血管风险并代表临床前血管疾病。我们确定了SDB是否会改变袖带阻断后血流介导的血管舒张（FMD）和峰值血流量（PBF）的增加。
对队列研究中的193名参与者（58%为女性）进行了整夜多导睡眠图检查及随后的肱动脉超声检查。使用呼吸暂停低通气指数（AHI）以及整夜低氧饱和度和觉醒频率指数对SDB进行量化。在基线时以及上臂袖带阻断5分钟后获取肱动脉的二维和多普勒速度测量值。FMD和PBF分别定义为肱动脉直径和血流量相对于基线的百分比变化。
在整个样本中，AHI与FMD（r = -0.30，P <.001）和PBF（r = -0.20，P <.001）均呈负相关。然而，按性别分层的单变量分析表明，这些关系仅在女性中存在。具体而言，AHI≥15的女性的FMD显著低于AHI得分较低的女性（P <.005），而男性中AHI与FMD之间无关联。此外，仅在女性中，PBF随AHI增加而显著降低（r = -0.29，P =.010）。在对体重指数、年龄和其他协变量进行调整的统计模型中，同样显示SDB严重程度显著影响FMD和PBF，性别与AHI之间存在显著交互作用，进一步证实SDB严重程度与内皮功能之间的关联在女性中比在男性中更强。
中度SBD与女性的血管传导和阻力内皮功能受损有关。患有SDB的女性可能比男性更容易患早期SDB相关的心血管疾病。
