Abstract:
Obesity is a common finding and a major pathogenetic factor in obstructive sleep apnea (OSA) in adults. To understand the mechanisms behind this, the present study investigated the tissue properties and respiratory kinematics of the tongue base and soft palate in the obese OSA minipig model. In 4 verified obese/OSA and 3 non-obese/non-OSA control minipigs, MRI fat-weighted images, ultrasound elastography (USE), and sleep video-fluoroscopy (SVF) were performed to quantify the fat composition, tissue stiffness, and respiratory kinematics of the tongue base and soft palate during sedated sleep. The results indicated that the fat composition gradually increased from the rostral to caudal tongue base, particularly in the posterior 1/3 of the tongue base, regardless of the presence of obesity and OSA. However, this trend was not seen in the soft palate and pharyngeal wall. The pharyngeal wall presented the highest fat composition as compared with the tongue base and soft palate. Overall, obese OSA minipigs showed stiffer tongue tissue than the controls, particularly in the rostral region of the tongue in obese Yucatan minipigs. The respiratory moving ranges of the soft palate were greater in both dorsal-ventral and rostral-caudal directions and during both respiratory and expiratory phases in OSA obese than control minipigs, and the largest moving ranges were seen in OSA obese Panepinto minipigs. The moving range of the tongue base was significantly smaller. These results suggest more fat infiltration in the caudal region of the tongue base regardless of the presence of obesity and/or OSA. The greater tissue stiffness of the tongue in obese OSA minipigs may result from altered neuromuscular drive.
摘要:
肥胖是成人阻塞性睡眠呼吸暂停(OSA)的常见发现和主要致病因素。为了理解这背后的机制,本研究调查了肥胖OSA小型猪模型中舌根和软腭的组织特性和呼吸运动学。在4只经过验证的肥胖/OSA和3只非肥胖/非OSA对照小型猪中,MRI脂肪加权图像,超声弹性成像(USE),和睡眠视频透视(SVF)进行量化脂肪成分,组织硬度,以及镇静睡眠期间舌根和软腭的呼吸运动学。结果表明,从鼻端到尾端舌根的脂肪成分逐渐增加,特别是在舌根的后部1/3,无论是否存在肥胖和OSA。然而,这种趋势在软腭和咽壁未见。与舌根和软腭相比,咽壁的脂肪成分最高。总的来说,肥胖的OSA小型猪表现出比对照组更硬的舌头组织,特别是在肥胖的尤卡坦小型猪的舌首区域。OSA肥胖者在背腹侧和头尾方向以及呼吸和呼气阶段的软腭呼吸移动范围均大于对照小型猪,最大的移动范围见于OSA肥胖Panepinto小型猪。舌根的移动范围明显较小。这些结果表明,无论是否存在肥胖和/或OSA,舌根的尾部区域都有更多的脂肪浸润。肥胖OSA小型猪的舌头组织硬度较大可能是由于神经肌肉驱动改变所致。