Sorbonne Université, INSERM UMRS 1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France.
AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pathologies du Sommeil, Département R3S, Paris, France.
Exp Physiol. 2019 Jun;104(6):887-895. doi: 10.1113/EP087468. Epub 2019 Mar 20.
What is the central question of this study? Moving to supine induces upper airway modifications and a fluid shift to the neck, which represent inspiratory load that predisposes to upper airway collapse. Is there cortical participation in the response to the load induced by transition to a supine posture in awake healthy subjects? What is the main finding and its importance? Moving to supine induces transient cortical activation in awake healthy subjects, with greater fluid shift, supporting possible cortical participation in the response to upper airway load induced by transition to a supine posture. Our findings open new perspectives in the understanding of the pathogenesis of obstructive sleep apnoea.
Moving from sitting upright to lying supine causes anatomical modifications and a fluid shift to the neck, which represent inspiratory loads that predispose to upper airway collapse. The pre-inspiratory potential (PIP) corresponds to the cortical activity observed during inspiratory load. In the sitting position during wakefulness, some obstructive sleep apnoea patients exhibit PIP, probably in relationship to upper airway abnormalities. The aim of this study was to investigate whether moving to the supine position induces respiratory-related cortical activation (PIP) in awake healthy subjects. The ECG was analysed to detect PIP, and EMG activity of the genioglossus muscle and ventilation were measured in the sitting position, immediately after moving to the supine position, and during application of leg positive pressure in the supine position to promote fluid shift, which was measured by bioelectrical impedance. Twenty-four subjects were included. From sitting to lying, PIP prevalence increased from 1/24 to 11/24 (P = 0.002), and ventilation decreased with no change in genioglossus activity. The fluid shift from sitting to supine was higher in the subjects exhibiting PIP while supine compared with the subjects without PIP [median (25th; 75th centiles) 440 (430; 520) versus 320 (275; 385) ml, P = 0.018], without any other differences. From before to during leg positive pressure, PIP disappeared (P = 0.006). These results indicate that moving from sitting to lying induces transient respiratory-related cortical activity in awake healthy subjects with greater fluid shift, supporting possible cortical participation in the response to upper airway loading induced by moving from sitting upright to lying supine. This study offers new perspectives in the understanding of obstructive sleep apnoea pathogenesis.
本研究的核心问题是什么？从坐姿改为仰卧位会引起上气道结构改变和液体向颈部转移，这代表吸气负荷，易导致上气道塌陷。清醒健康受试者由仰卧位改为仰卧位时，是否存在皮质参与对负荷的反应？主要发现及其重要性是什么？从坐姿改为仰卧位会引起清醒健康受试者的短暂皮质激活，液体转移量更大，支持皮质可能参与由改为仰卧位引起的上气道负荷的反应。我们的发现为理解阻塞性睡眠呼吸暂停的发病机制开辟了新的视角。
从坐立位改为仰卧位会引起解剖学改变和液体向颈部转移，这代表吸气负荷，易导致上气道塌陷。预吸气电位（PIP）对应于清醒时吸气负荷期间观察到的皮质活动。在清醒时的坐姿中，一些阻塞性睡眠呼吸暂停患者表现出 PIP，可能与上气道异常有关。本研究旨在探讨改为仰卧位是否会引起清醒健康受试者的呼吸相关皮质激活（PIP）。分析心电图以检测 PIP，测量颏舌肌的肌电图活动和通气，在坐姿、改为仰卧位后即刻以及仰卧位时施加腿部正压以促进液体转移时进行测量，液体转移通过生物电阻抗测量。共纳入 24 名受试者。从坐姿改为仰卧位时，PIP 的发生率从 1/24 增加到 11/24（P=0.002），通气减少而颏舌肌活动无变化。改为仰卧位时，表现出 PIP 的受试者与没有 PIP 的受试者相比，液体转移量更高[中位数（25 分位；75 分位）440（430；520）与 320（275；385）ml，P=0.018]，无其他差异。从施加腿部正压前到施加腿部正压期间，PIP 消失（P=0.006）。这些结果表明，从坐姿改为仰卧位会引起清醒健康受试者的短暂呼吸相关皮质活动，液体转移量更大，支持皮质可能参与由从坐姿改为仰卧位引起的上气道负荷的反应。本研究为理解阻塞性睡眠呼吸暂停的发病机制提供了新的视角。
