Vascular Functions in Children with Sleep Disorder Breathing

描述（由申请人提供）：儿童睡眠呼吸障碍综合征（SDB）包括单纯打鼾、阻塞性低通气（OH）和不同程度的阻塞性睡眠呼吸暂停（OSA）。在所有儿童中，有超过12%的儿童患有该综合征，其中大多数属于轻度至中度的严重程度范围。虽然严重SDB的长期心血管后遗症已得到充分认识，但那些继发于轻度SDB的后遗症仍未明确。由于对不太严重的SDB形式的长期心血管发病率缺乏了解，因此无法对患有该疾病的儿童进行适当的管理，也无法在成年期预防心血管疾病。我们之前报道了一项新的观察结果，SDB患儿的左心室重构和肥厚独立于持续的高血压和肥胖发生。然而，左心室重构的机制尚不清楚。我们在患有SDB的儿童中提供了新的初步数据，显示血浆急性期反应物水平与左心室质量之间有很强的关联。此外，我们提出了有趣的初步数据，首次表明与对照组相比，患有SDB的瘦弱和肥胖儿童颈动脉的结构和功能发生了变化，收缩压更高，脉压更宽。这些都是血管硬度的重要指标和左心室负荷和质量的决定因素。本研究的目的有三个方面：1)比较5- 13岁不同程度SDB儿童与正常对照组的炎症性心血管疾病机制；2)确定血浆中细胞因子水平与扁桃体中细胞因子水平的关系；3)检查炎症标志物与预后重要心血管指标（如颈动脉内膜厚度、颈动脉顺应性、脉压、主动脉硬度、左心室质量和功能）在腺扁桃体切除术前后的关系。

DESCRIPTION (provided by applicant): The pediatric syndrome of sleep disordered breathing (SDB) encompasses children with simple snoring, obstructive hypoventilation (OH), and varying degrees of obstructive sleep apnea (OSA). The syndrome occurs in more than 12% of all children, with most falling within the mild to moderate range of the severity spectrum. Although the long-term cardiovascular sequelae of severe SDB are well recognized, those that develop secondary to milder forms of SDB remain undefined. The lack of knowledge regarding the long-term cardiovascular morbidity of less severe forms of SDB precludes adequate management of children with the disorder and prevention of cardiovascular disease during adulthood. We have previously reported a novel observation that left ventricular remodeling and hypertrophy in children with SDB occurs independently of sustained hypertension and obesity. The mechanism of left ventricular remodeling however remains undefined. We present novel preliminary data in children with SDB showing a strong association between plasma level of acute phase reactants and left ventricular mass. Moreover, we present intriguing preliminary data demonstrating for the first time that compared to controls, lean and obese children with SDB have structural and functional changes of the carotid artery, higher systolic blood pressure and wider pulse pressure. All are important indicators of blood vessel stiffness and determinants of left ventricular load and mass.The goals of this study are threefold: 1) to compare inflammatory cardiovascular disease mechanisms in 5- to 13-year-old children with varying degrees of SDB to those in normal controls; 2) to determine how cytokine levels in plasma relate to those in tonsils; 3) to examine the relationship between inflammatory markers and prognostically important cardiovascular measures such as carotid intima thickness, carotid compliance, pulse pressure, aortic stiffness and left ventricular mass and function before and after adenotonsillectomy.