Carlson J T, Hedner J, Elam M, Ejnell H, Sellgren J, Wallin B G
Department of Pulmonary Medicine, Reström's Hospital, Goteborg, Sweden.
Chest. 1993 Jun;103(6):1763-8. doi: 10.1378/chest.103.6.1763.
Muscle nerve sympathetic activity (MSA) was recorded during wakefulness in 11 patients with obstructive sleep apnea (OSA) and in 9 sex- and age-matched healthy control subjects. Plasma levels of norepinephrine (NE) and neuropeptide Y were analyzed. Five patients had established hypertension (resting supine systolic BP/diastolic BP > or = 160/95 mm Hg). The investigation was performed after a minimum of 3 weeks' washout period of antihypertensive medication. Muscle sympathetic activity during supine rest was higher in patients compared with controls (p < 0.01) with no difference between normotensive and hypertensive patients. However, systolic, but not diastolic, BP was positively related to resting MSA (n = 20, p < 0.01). There was no significant correlation between body mass index and MSA. Resting MSA was unrelated to disease severity expressed as apnea frequency or minimum SaO2 during the overnight recording. Both the arterial and venous plasma norepinephrine was higher in patients compared with controls (p < 0.05). Plasma levels of NE correlated to resting MSA (p < 0.01) in the whole study group (patients and controls) but not within the respective subgroups. No significant correlation, however, was found between plasma NE (arterial and venous) and BP. Plasma neuropeptide Y-like immunoreactivity was similar in patients and controls. However, one patient with hypertension had approximately twice this level in repeated samples. It is concluded that neurogenic sympathetic activity as well as circulating plasma NE is increased in patients with OSA. This increased sympathetic activity during awake supine rest may reflect a pathophysiologic adaptation to hypoxia and hemodynamic changes occurring at repetitive apneas during sleep. The correlation between MSA and systolic BP implies that this mechanism may be directly or indirectly involved in the development of cardiovascular complications in OSA.
在11例阻塞性睡眠呼吸暂停（OSA）患者和9名性别及年龄匹配的健康对照者清醒状态下记录肌肉神经交感神经活动（MSA）。分析去甲肾上腺素（NE）和神经肽Y的血浆水平。5例患者患有确诊的高血压（静息仰卧位收缩压/舒张压≥160/95mmHg）。在至少停用抗高血压药物3周的洗脱期后进行该研究。与对照组相比，患者仰卧位休息时的肌肉交感神经活动更高（p<0.01），血压正常和高血压患者之间无差异。然而，收缩压而非舒张压与静息MSA呈正相关（n=20，p<0.01）。体重指数与MSA之间无显著相关性。静息MSA与以夜间记录期间的呼吸暂停频率或最低血氧饱和度表示的疾病严重程度无关。与对照组相比，患者的动脉和静脉血浆去甲肾上腺素均更高（p<0.05）。在整个研究组（患者和对照组）中，NE的血浆水平与静息MSA相关（p<0.01），但在各个亚组中不相关。然而，未发现血浆NE（动脉和静脉）与血压之间存在显著相关性。患者和对照组的血浆神经肽Y样免疫反应性相似。然而，一名高血压患者的重复样本中该水平约为两倍。结论是，OSA患者的神经源性交感神经活动以及循环血浆NE增加。清醒仰卧位休息期间这种交感神经活动增加可能反映了对睡眠期间反复呼吸暂停时发生的缺氧和血流动力学变化的病理生理适应。MSA与收缩压之间的相关性意味着该机制可能直接或间接参与OSA心血管并发症的发生。
