Impact of CPAP on Functional Outcomes in Milder OSA

描述（由申请人提供）：阻塞性睡眠呼吸暂停（OSA）根据美国睡眠医学学会定义的每小时睡眠呼吸障碍（RDI）次数，可分为轻度、中度或重度。持续气道正压通气（CPAP）是睡眠呼吸暂停的主要治疗方法。当应用该装置时，通过该装置输送到上气道的压力柱立即消除呼吸干扰。来自随机对照研究的证据表明，CPAP还可以改善严重OSI患者的功能状态和OSA的主要表现，即白天过度嗜睡，即，RDI >30。然而，探索改善不太严重的OSA患者的功能状态的工作有限，即，轻度（RDI 5-15）或中度（RDI 16-30）疾病。在与OSA相关的功能结局的对照研究中报告的大安慰剂效应要求在评估这种治疗的真实影响的研究中需要安慰剂。三项针对轻度阻塞性睡眠呼吸暂停的随机对照研究的结果主要是由于严重的方法学局限性而模棱两可。目前尚不清楚CPAP治疗是否改善了轻度疾病患者的日常功能（RDI 5-30）。这是一个关键问题，因为这种疾病严重程度代表了OSA的最大部分，占美国人口的15%。使用格兰杰功能评估模型，我们的主要目的是确定轻度OSA患者在CPAP治疗后功能状态是否改善。我们将采用随机安慰剂对照平行组设计，使用假CPAP装置作为安慰剂，在大样本中显示显著的日间嗜睡。我们将检验以下假设：与假CPAP相比，接受活性CPAP治疗的患者在治疗8周后的功能状态变化（通过睡眠功能结局问卷测量）更大。该研究的次要目的是：1）检查CPAP是否也能改善日间嗜睡; 2）确定CPAP是否能降低夜间血压，以降低与OSA相关的中风和高血压风险。

DESCRIPTION (provided by applicant): Obstructive sleep apnea (OSA) is characterized as mild, moderate, or severe according to the number of respiratory disturbances per hour of sleep (RDI) as defined by the American Academy of Sleep Medicine. Continuous positive airway pressure (CPAP) is the primary treatment for sleep apnea. The column of pressure delivered to the upper airway by this device immediately eliminates the respiratory disturbances when it is applied. There is evidence from randomized controlled studies that CPAP also improves functional status, and the key manifestation of OSA, excessive daytime sleepiness, in individuals with severe OSI, i.e., RDI >30. However, there has been limited work exploring improvement in functional status in patients with less severe OSA, i.e., those with mild (RDI 5-15) or moderate (RDI 16-30) disease. The large placebo effect that has been reported in controlled studies of functional outcomes associated with OSA mandates the need for a placebo in investigations evaluating the true impact of this treatment. Results from the three randomized controlled studies in milder OSA that have examined this issue have been equivocal principally because of serious methodological limitations. It remains unclear whether CPAP treatment improves daily functioning in those with milder disease (RDI 5-30). This is a critical issue as this level of disease severity represents the largest segment of OSA and comprises 15% of the US population. Using Granger's model of functional assessment our primary aim is to determine whether functional status improves in patients with milder OSA following CPAP treatment. We will employ a randomized placebo-controlled parallel groups design using a sham-CPAP device as the placebo in a large sample manifesting significant daytime sleepiness. We will test the hypothesis that the change in functional status (measured by the Functional Outcomes of Sleep Questionnaire) after 8 weeks of treatment will be greater for patients treated with active CPAP compared to sham CPAP. Secondary aims of the study are: 1) to examine whether CPAP also improves daytime sleepiness; 2) to determine whether CPAP can reduce nocturnal blood pressure to lower the risk for stroke and hypertension linked to OSA.