Li Wen-Yang, Gakwaya Simon, Saey Didier, Sériès Frédéric
Unité de Recherche en Pneumologie, Centre de Recherche, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada; and.
The 1st Affiliated Hospital of China Medical University, Shen Yang City, Liao Ning Province, China.
J Appl Physiol (1985). 2017 Jul 1;123(1):116-125. doi: 10.1152/japplphysiol.00934.2016. Epub 2017 Apr 13.
Inadequate upper airway (UA) dilator muscle function may play an important role in the pathophysiology of obstructive sleep apnea (OSA). To date, tongue mechanical properties have been assessed mainly using protrusion protocol with conflicting results. Performance during elevation tasks among patients with OSA remains unknown. This study aimed at assessing tongue muscle strength, strength stability, endurance time, fatigue indices, and total muscle work, using elevation and protrusion tasks with repetitive isometric fatiguing contractions in 12 normal plus mild, 17 moderate, and 11 severe patients with OSA, and to assess the influence of body mass index (BMI) and age. Endurance time was longer in protrusion than elevation task ( = 0.01). In both tasks, endurance time was negatively correlated with baseline value of strength coefficient of variation ( < 0.01). Compared with other groups, patients with moderate OSA had the lowest total muscle work for protrusion ( = 0.01) and shortest endurance time ( = 0.04), regardless of the type of task. Additionally, in patients with moderate-severe OSA, the total muscle work for both tasks was lower in nonobese compared with obese ( < 0.05). Total muscle work for protrusion was positively correlated with apnea hypopnea index (AHI) in obese subjects ( < 0.01). Endurance time was shorter ( < 0.01) and recovery time longer ( = 0.02) in the old compared with young subjects. In conclusion, the tongue is more prone to fatigue during the elevation task and in patients with moderate OSA. Obesity appeared to prevent alteration of tongue mechanical properties in patients with OSA. Baseline strength stability and endurance were related, illustrating the role of central neuromuscular output in tongue resistance to fatigue. To our knowledge, this is the first study to assess and compare tongue function using both elevation and protrusion tasks with repetitive isometric fatiguing contractions in subjects with different OSA status. Tongue mechanical performance seemed to differ between protrusion and elevation tasks and depend on the severity of OSA.
上气道（UA）扩张肌功能不足可能在阻塞性睡眠呼吸暂停（OSA）的病理生理学中起重要作用。迄今为止，主要使用前伸方案评估舌的力学特性，但结果相互矛盾。OSA患者在抬高任务中的表现仍不清楚。本研究旨在通过对12名正常及轻度、17名中度和11名重度OSA患者进行重复等长疲劳收缩的抬高和前伸任务，评估舌肌力量、力量稳定性、耐力时间、疲劳指数和总肌肉功，并评估体重指数（BMI）和年龄的影响。前伸任务中的耐力时间比抬高任务更长（P = 0.01）。在两项任务中，耐力时间与力量变异系数的基线值呈负相关（P < 0.01）。与其他组相比，中度OSA患者无论任务类型如何，前伸的总肌肉功最低（P = 0.01），耐力时间最短（P = 0.04）。此外，在中重度OSA患者中，非肥胖者两项任务的总肌肉功均低于肥胖者（P < 0.05）。肥胖受试者前伸的总肌肉功与呼吸暂停低通气指数（AHI）呈正相关（P < 0.01）。与年轻受试者相比，老年受试者的耐力时间更短（P < 0.01），恢复时间更长（P = 0.02）。总之，在抬高任务中以及中度OSA患者中，舌更容易疲劳。肥胖似乎可防止OSA患者舌力学特性的改变。基线力量稳定性和耐力相关，说明了中枢神经肌肉输出在舌抗疲劳中的作用。据我们所知，这是第一项在不同OSA状态的受试者中使用重复等长疲劳收缩的抬高和前伸任务来评估和比较舌功能的研究。舌的力学表现似乎在前伸和抬高任务之间有所不同，并取决于OSA的严重程度。
