Obesity & OSA: Understanding the Importance of Tongue Fat and Metabolic Function

描述（由申请人提供）：睡眠呼吸暂停是一种常见的疾病，发病率很高，影响至少4%的中年男性和2%的中年女性。肥胖被认为是阻塞性睡眠呼吸暂停最重要的危险因素，但我们不知道肥胖是如何导致睡眠呼吸暂停的。并非所有肥胖者都有睡眠呼吸暂停。本提案的重点是通过检查舌头的组织特性和生物学行为来理解肥胖和阻塞性睡眠呼吸暂停之间的关系。特别是，我们将使用高清晰度体积自旋回声MRI检查舌头脂肪，Dixon成像检查脂肪和水以及磁共振光谱，并使用PET成像检查睡眠呼吸暂停患者和体重匹配对照组在减肥前后的舌头代谢功能。一半的受试者通过药物减肥，另一半通过手术减肥。了解肥胖如何影响上呼吸道功能是至关重要的，这样我们才能为睡眠呼吸暂停患者确定更好的治疗方案和预防策略。这一建议是基于一个总体假设，即与体重匹配的对照组相比，睡眠呼吸暂停患者的舌头会有更多的脂肪，舌头的代谢活动也会增加。我们的具体目的是：1)比较呼吸暂停和体重匹配对照组的舌部和其他上呼吸道软组织结构的组织特性和代谢功能；2)确定减肥后这些结构的组织特性和代谢功能的差异。我们的资源，包括先进的静态和动态磁共振成像技术，新颖的体积计算机图形图像分析范式，世界知名的PET成像中心以及睡眠呼吸暂停生物统计，多导睡眠图，上呼吸道成像，减肥研究，Pcrit和舌力测量方面的专业知识，将使我们能够实现我们的具体目标。

DESCRIPTION (provided by applicant): Sleep apnea is a common disorder with significant morbidity that affects at least 4% of middle-aged males and 2% of middle-aged females. Obesity is thought to be the most important risk factor for obstructive sleep apnea yet we do not understand how obesity predisposes to sleep apnea. Not all obese subjects have sleep apnea. The focus of this proposal is directed towards understanding the relationship between obesity and obstructive sleep apnea by examining tissue properties and the biologic behavior of the tongue. In particular we will examine tongue fat with high definition volumetric spin echo MRI, Dixon imaging for fat and water and MR spectroscopy and the metabolic function of the tongue with PET imaging in patients with sleep apnea and weight matched controls before and after weight loss. Weight loss will be achieved medically in half the subjects and surgically in half of the subjects. It is critical to understand exactly how obesity affects upper airway function in order for us to determine better treatment options and preventive strategies for patients with sleep apnea. This proposal is based on the overall hypotheses that patients with sleep apnea will have more fat in the tongue and increased metabolic activity of the tongue as compared to weight matched controls. Our specific aims are: 1) To compare the tissue properties and metabolic function of the tongue and other upper airway soft tissue structures in apneics and weight-matched controls without apnea; and 2) to determine the differences in the tissue properties and metabolic function of the these structures after weight loss. Our resources, which include advanced static and dynamic MR imaging techniques, novel volumetric computer graphics image analysis paradigms, a world renown PET imaging center and expertise in sleep apnea biostatistics, polysomnography, imaging the upper airway, weight loss studies, Pcrit and tongue force measurements will allow us to achieve our specific aims. PUBLIC HEALTH RELEVANCE: Obesity is reaching epidemic proportions in this country. Obesity is the biggest risk factor for obstructive sleep apnea, a condition characterized by snoring, daytime sleepiness and airway closure during sleep. This grant is designed to understand the relationship between obesity and sleep apnea so that we can determine optimal treatment strategies for this disorder.