Effect of overnight nasal continuous positive airway pressure treatment on the endothelial function in patients with obstructive sleep apnea.

<bold>Objective: </bold>In this prospective study, we aimed to investigate acute effect of nasal continuous positive airway pressure (CPAP) therapy on the endothelial function of patients with obstructive sleep apnea syndrome (OSA) by using brachial artery flow mediated dilatation (FMD) method. <bold>Methods: </bold>Newly diagnosed thirty OSA patients with ages between 29 and 72 years were included in this study. FMD and high sensitivity C-reactive protein (hsCRP) values of patients obtained before and after CPAP dose titration test were compared with paired samples t test or Wilcoxon signed ranks test. <bold>Results: </bold>With CPAP therapy apnea hypopnea indices were reduced (60.6±24.9/h vs. 9.6±7.9/h; p<0.001) and oxygen desaturation indices recovered (50±27/h vs. 6±7/h; p<0.001). Heart rates of patients decreased after CPAP therapy (80±10/min vs. 73±8/min; p=0.003). FMD values significantly increased after CPAP (8.55±5.82 percent vs. 12.08±7.17 percent; p=0.003). HsCRP values after CPAP were not different from baseline values. <bold>Conclusion: </bold>Acute improvement of the endothelial function with one night CPAP therapy suggests endothelial dysfunction in OSA patients to be result of acute pathophysiologic factors. In intermediate and severe OSA patients, CPAP therapy may be considered in acute treatment of diseases associated with endothelial dysfunction. [ABSTRACT FROM AUTHOR]