Sleep Research Laboratory, St. Vincent's University Hospital, Dublin, Ireland.
Respir Physiol Neurobiol. 2012 Aug 15;183(2):59-66. doi: 10.1016/j.resp.2012.05.024. Epub 2012 Jun 4.
Obstructive sleep apnea (OSA) is a prevalent disorder that may cause cardiovascular disease and fatal traffic accidents but the pathophysiology remains incompletely understood. Increased fatigability of the genioglossus (the principal upper airway dilator muscle) might be important in OSA pathophysiology but the existing literature is uncertain. We hypothesized that the genioglossus in OSA subjects would fatigue more than in controls. In 9 OSA subjects and 9 controls during wakefulness we measured maximum voluntary tongue protrusion force (Tpmax). Using surface electromyography arrays we measured the rate of decline in muscle fiber conduction velocity (MFCV) during an isometric fatiguing contraction at 30% Tpmax. The rate of decline in MFCV provides an objective means of quantifying localized muscle fatigue. Linear regression analysis of individual subject data demonstrated a significantly greater decrease in MFCV in OSA subjects compared to control subjects (29.2 ± 20.8% [mean ± SD] versus 11.2 ± 20.8%; p=0.04). These data support increased fatigability of the genioglossus muscle in OSA subjects which may be important in the pathophysiology of OSA.
阻塞性睡眠呼吸暂停（OSA）是一种普遍存在的疾病，可能导致心血管疾病和致命的交通事故，但病理生理学仍不完全清楚。颏舌肌（主要的上气道扩张肌）的疲劳增加可能在 OSA 病理生理学中很重要，但现有文献并不确定。我们假设 OSA 患者的颏舌肌比对照组更容易疲劳。在 9 名 OSA 患者和 9 名对照组在清醒期间，我们测量了最大自主舌伸肌力（Tpmax）。使用表面肌电图阵列，我们在 30%Tpmax 的等长疲劳收缩期间测量了肌纤维传导速度（MFCV）下降的速率。MFCV 的下降速率提供了量化局部肌肉疲劳的客观手段。个体受试者数据的线性回归分析表明，与对照组相比，OSA 患者的 MFCV 下降幅度明显更大（29.2±20.8%[平均值±标准差]与 11.2±20.8%；p=0.04）。这些数据支持 OSA 患者颏舌肌疲劳增加，这可能在 OSA 的病理生理学中很重要。
