Popovic R M, White D P
University of Colorado Health Sciences Center, Denver Veterans Administration Medical Center 80220, USA.
Am J Respir Crit Care Med. 1995 Aug;152(2):725-31. doi: 10.1164/ajrccm.152.2.7633734.
Obstructive sleep apnea is generally recognized as more common in men than in women. This could relate to gender differences in either ventilatory control mechanisms or the structure and function of the pharyngeal airway. Most studies suggest that women have a structurally smaller pharyngeal airway than men, which would likely predispose rather than protect them from airway collapse. However, pharyngeal airway patency is actually a dynamic interaction between anatomy and pharyngeal muscle activity. We therefore hypothesized that females may have increased pharyngeal dilator muscle activity, thereby protecting them from airway collapse during sleep. To test this hypothesis, we compared genioglossal EMG (GG-EMG, measured as a percentage of maximal muscle activity) and upper airway resistance in 22 healthy subjects, 11 males and 11 females, during wakefulness. No significant difference in pharyngeal resistance could be found between the genders. However, inspiratory peak phasic and expiratory tonic GG-EMG activity were both significantly greater in females (GG-EMG peak phasic; 24.3 +/- 3.8 versus 13.1 +/- 4.5% of maximum, p < 0.02; GG-EMG tonic; 12.2 +/- 2.8 versus 4.7 +/- 1.2% of maximum, p < 0.01). In addition, females demonstrated a significant EMG response to inspiratory loading that was not observed in men. We conclude that women have, under basal conditions during wakefulness, augmented genioglossal muscle activity compared with men. To the extent that this augmented muscle activity is maintained across states, the female airway may be more stable and less collapsible.
阻塞性睡眠呼吸暂停通常被认为在男性中比在女性中更为常见。这可能与通气控制机制或咽气道的结构和功能方面的性别差异有关。大多数研究表明，女性的咽气道在结构上比男性小，这可能使她们更容易发生气道塌陷，而不是起到保护作用。然而，咽气道通畅实际上是解剖结构与咽部肌肉活动之间的动态相互作用。因此，我们推测女性可能具有增强的咽部扩张肌活动，从而在睡眠期间保护她们不发生气道塌陷。为了验证这一假设，我们比较了22名健康受试者（11名男性和11名女性）在清醒状态下的颏舌肌肌电图（GG-EMG，以最大肌肉活动的百分比来衡量）和上气道阻力。两性之间在咽部阻力方面未发现显著差异。然而，女性的吸气相峰值和呼气相持续性GG-EMG活动均显著更高（GG-EMG峰值吸气相；分别为最大值的24.3±3.8%与13.1±4.5%相比，p<0.02；GG-EMG持续性；分别为最大值的12.2±2.8%与4.7±1.2%相比，p<0.01）。此外，女性对吸气负荷表现出显著的肌电图反应，而男性未观察到这种反应。我们得出结论，在清醒状态下的基础条件下，与男性相比，女性的颏舌肌活动增强。就这种增强的肌肉活动在不同状态下得以维持而言，女性气道可能更稳定，更不易塌陷。
