Grebe Mathias, Eisele Hans Joachim, Weissmann Norbert, Schaefer Christian, Tillmanns Harald, Seeger Werner, Schulz Richard
Division of Cardiology and Angiology, Department of Internal Medicine, Justus-Liebig University, Giessen, Germany.
Am J Respir Crit Care Med. 2006 Apr 15;173(8):897-901. doi: 10.1164/rccm.200508-1223OC. Epub 2006 Jan 26.
Obstructive sleep apnea (OSA) is associated with oxidative stress, endothelial dysfunction, and increased cardiovascular morbidity and mortality.
We tested the hypothesis that endothelial dysfunction in patients with OSA is linked to oxidative stress.
In the present study, we measured flow-mediated dilation (FMD) of the brachial artery by ultrasound in 10 otherwise healthy, untreated patients with OSA and 10 age-and sex-matched control subjects without sleep-disordered breathing before and after intravenous injection of the antioxidant vitamin C. The investigator performing the FMD measurements was blinded to the status of the patients.
When compared with control subjects, baseline FMD was significantly reduced in the patients with OSA. After intravenous injection of 0.5 g vitamin C, vasoreactivity remained unchanged in the control subjects. In the patients with OSA, ascorbate led to an increase in FMD to a level comparable to that observed in the control group.
The reduced endothelial-dependent vasodilation in untreated patients with OSA acutely improves by the free radical scavenger vitamin C. These results are in favor of oxidative stress being responsible for the endothelial dysfunction in OSA. Antioxidant strategies should be explored for the treatment of OSA-related cardiovascular disease.
阻塞性睡眠呼吸暂停（OSA）与氧化应激、内皮功能障碍以及心血管疾病发病率和死亡率增加有关。
我们检验了OSA患者内皮功能障碍与氧化应激相关的假说。
在本研究中，我们通过超声测量了10名其他方面健康的未经治疗的OSA患者和10名年龄及性别匹配、无睡眠呼吸紊乱的对照受试者在静脉注射抗氧化剂维生素C前后肱动脉的血流介导的血管舒张（FMD）。进行FMD测量的研究人员对患者的状态不知情。
与对照受试者相比，OSA患者的基线FMD显著降低。静脉注射0.5 g维生素C后，对照受试者的血管反应性保持不变。在OSA患者中，抗坏血酸导致FMD增加至与对照组相当的水平。
未经治疗的OSA患者内皮依赖性血管舒张功能降低可通过自由基清除剂维生素C得到急性改善。这些结果支持氧化应激是OSA内皮功能障碍的原因。应探索抗氧化策略用于治疗OSA相关的心血管疾病。
